JP5660853B2 - Electrophoretic display medium sheet and electrophoretic display medium using the same - Google Patents

Description

  The present invention relates to a sheet for an electrophoretic display medium capable of reversibly changing a visual state by the action of an electric field or the like, and an electrophoretic display medium using the same.

  In recent years, there has been an increasing demand for display devices with lower power consumption, thinner and lighter, more flexible, and the electronic paper has been attracting attention as one of them. An electrophoretic display device using electrophoretic ink or the like is known as one of such electronic papers. This electrophoretic display device has a configuration in which two electrode substrates, at least one of which is transparent, are arranged to face each other, and an electrophoretic ink is provided between the electrodes arranged to face each other to form a display panel. A display is obtained on the transparent electrode surface by applying an electric field to the display panel.

  The electrophoretic ink to be used is one in which one or more kinds of electrophoretic particles are dispersed in a dispersion medium. By applying an electric field from the outside, the particles move in the dispersion medium, An arbitrary display is obtained. In addition to the electrophoretic particles, the electrophoretic ink may be provided with additives such as uncharged particles, surfactants, dyes, and dispersants.

Such an electrophoretic display device can obtain a desired display by moving the electrophoretic particles in the electrophoretic ink by controlling the direction of the electric field. It has the advantages of being as wide as ordinary printed matter, having low power consumption, and having a display memory property.
However, the electrophoretic particles used in the electrophoretic ink have a problem that the particles are likely to aggregate due to long-term storage, and the display is liable to be deteriorated due to uneven distribution of particles during repeated display. Therefore, there has been proposed a method for suppressing aggregation and uneven distribution of particles by dividing and filling electrophoretic ink into a large number of finely isolated cells (small sections).

For the formation of cells (small compartments) for finely separating electrophoretic ink, microcapsules, embossing, photoresist, etc. are used. When using methods other than microcapsules, electrophoretic particles are used. In order to suppress the aggregation and uneven distribution of each other, it is necessary to prevent a gap between the structure formed on one substrate side and the other substrate.
Therefore, as a structure or manufacturing method in which the upper surface of the structure and the counter substrate are bonded together without any gap, for example, 1-1) sandwiched between the first base material or electrode layer and the second base material or electrode layer. An electrophoretic display comprising a display cell filled with an electrophoretic fluid and top-sealed, wherein the adhesive composition comprises a high dielectric polymer or oligomer and a radiation curable composition, Second substrate or electrode layer filled with electrophoretic fluid and electrophoretic display laminated to top-sealed display cell, 1-2) filled with electrophoretic fluid, high dielectric polymer or oligomer and radiation curing An electrophoretic display comprising a display cell top-sealed with a top-sealing composition comprising an active composition, 1-3) A method for improving the physico-mechanical and electro-optical properties of an electrophoretic display, wherein a top-sealing composition comprising the high dielectric polymer or oligomer and a radiation curable composition is used to fill the electrophoretic fluid. 1-4) a) an array of top-sealed display cells filled with electrophoretic fluid on the temporary substrate layer, and b) high dielectric properties. An adhesive layer formed from an adhesive composition comprising a polymer or oligomer and a radiation curable composition, comprising an electrode or substrate layer adhered to the top of a display cell that is filled with the electrophoretic fluid and top-sealed. Semi-finished display panel comprising 1-5) a) display cell filled with electrophoretic fluid or liquid crystal on electrode or substrate layer A display cell filled with the electrophoretic fluid or liquid crystal is top-sealed with a top-seal composition comprising a high dielectric polymer or oligomer and a radiation curable composition; and b) A semi-finished display panel comprising a temporary substrate laminated to the top of a top-sealed display cell filled with the electrophoretic fluid or liquid crystal, 1-6) a) electrophoresis on the temporary substrate An array of display cells filled with fluid, wherein the display cells filled with electrophoretic fluid are top-seal compositions comprising a high dielectric polymer or oligomer and a radiation curable composition, top-seal And b) an electrode or substrate laminated to the top of a display cell that is filled and top-sealed with the electrophoretic fluid. A semi-finished display panel including a material layer is known (for example, see Patent Document 1).

  However, in each of the structures 1-1) to 1-5) described in Patent Document 1 and the electrophoretic display medium obtained by the production method thereof, the top-seal composition and the ink are compatible. There is still a problem in structural durability and display durability because the liquid top-seal composition is applied on the electrophoretic fluid or liquid crystal which is liquid deterioration, and further structural durability At present, electrophoretic display media having excellent display durability are desired.

JP-T-2006-517038 (Claims, Examples, etc.)

  The present invention has been made in view of the above-described problems and current state of the prior art, and is intended to solve this problem, and an electrophoretic display medium sheet capable of improving the structural durability and display durability of an electrophoretic display medium, and An object of the present invention is to provide an electrophoretic display medium using the same.

  As a result of intensive studies to solve the above-described conventional problems, the present inventors have sealed the electrophoretic ink that is disposed opposite to the substrate, the electrophoretic ink having specific properties, and the electrophoretic ink having specific properties. It has been found that a sheet for an electrophoretic display medium can be obtained by having a film having specific physical properties, and a structure formed between the substrate and the film having the specific physical properties. The inventors have found that the electrophoretic display medium can be obtained by laminating the electrophoretic display medium sheet on an arbitrary substrate, and the present invention has been completed.

That is, the present invention resides in the following (1) to (9).
(1) A substrate having optical transparency, an electrophoretic ink having a volume specific resistance of 1 × 10 ⁷ to 1 × 10 ¹³ Ω · cm when an alternating current of 100 Hz is applied, and an electrophoretic ink disposed opposite to the substrate It has a film whose resistance value when applying alternating current of 100 Hz or more for sealing is 5 times or less of the resistance value of electrophoretic ink, and a structure formed between the substrate and the sealing film. Sheet for electrophoretic display medium.
(2) The film is at least one selected from a polyvinylidene chloride film, a polyvinylidene fluoride film, a film containing vinylidene chloride or vinylidene fluoride as a constituent unit, and a film containing vinylidene chloride or vinylidene fluoride as a polymer blend. The sheet for electrophoretic display media as described in (1) above, wherein
(3) The sheet for electrophoretic display media according to (1) or (2), wherein the film contains a plasticizer.
(4) The sheet for electrophoretic display media according to any one of (1) to (3), wherein the structure is formed on a substrate.
(5) The sheet for electrophoretic display media according to (4), wherein the structure is laminated with the film via an adhesive layer.
(6) The sheet for electrophoretic display media according to any one of (1) to (3), wherein the structure is formed on the film.
(7) The sheet for electrophoretic display media according to (6) above, wherein the structure is laminated with the substrate via an adhesive layer.
(8) The sheet for electrophoretic display media according to (5) or (7), wherein the adhesive layer is a hot-melt adhesive layer.
(9) An electrophoretic display medium, wherein a substrate is laminated on the film of the electrophoretic display medium sheet according to any one of (1) to (8).

  ADVANTAGE OF THE INVENTION According to this invention, the sheet | seat for electrophoretic display media which improved the structural durability and display durability of the electrophoretic display medium, and an electrophoretic display medium using the same are provided.

It is a schematic longitudinal cross-sectional view which shows the sheet | seat for electrophoretic display media of 1st Embodiment of this invention. (A)-(d) is the schematic drawing explaining the manufacturing process of the sheet | seat for electrophoretic display media of 1st Embodiment of this invention for every process. (A)-(d) is the schematic drawing explaining the manufacturing process of the sheet | seat for electrophoretic display media of 2nd Embodiment of this invention for every process. It is a schematic longitudinal cross-sectional view which shows the sheet | seat for electrophoretic display media of 3rd Embodiment of this invention. (A)-(e) is the schematic drawing explaining the manufacturing process of the sheet | seat for electrophoretic display media of 3rd Embodiment of this invention for every process. It is a schematic longitudinal cross-sectional view which shows the sheet | seat for electrophoretic display media of 4th Embodiment of this invention. (A)-(d) is the schematic drawing explaining the manufacturing process of the sheet | seat for electrophoretic display media of 4th Embodiment of this invention for every process. (A)-(d) is the schematic drawing explaining the manufacturing process of the sheet | seat for electrophoretic display media of 5th Embodiment of this invention for every process. It is a schematic longitudinal cross-sectional view which shows the sheet | seat for electrophoretic display media of 6th Embodiment of this invention. (A)-(e) is the schematic drawing explaining the manufacturing process of the sheet | seat for electrophoretic display media of 7th Embodiment of this invention for every process. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 and FIG. 2 are schematic longitudinal sectional views showing an electrophoretic display medium sheet according to the first embodiment of the present invention, and schematic diagrams for explaining the manufacturing process of the electrophoretic display medium sheet step by step.
As shown in FIGS. 1 and 2, the sheet A for electrophoretic display medium according to the first embodiment of the present invention is obtained when a substrate 10 having optical transparency, electrophoretic ink 20, and an alternating current of 100 Hz are applied. The resistance value when the electrophoretic ink 20 having a volume resistivity of 1 × 10 ⁷ to 1 × 10 ¹³ Ω · cm and an alternating current of 100 Hz or more that is disposed opposite to the substrate and seals the electrophoretic ink is applied. And a structure 15 formed between the substrate 10 and the ink sealing film 30.

The light-transmitting substrate 10 may be any substrate that is light-transmitting and has electrodes. For example, the electrode layer 12 is provided on the base material 11, and the insulating structure is provided on the electrode layer 12. The body 15 can be formed.
The substrate 11 is, for example, a transparent inorganic material such as glass, quartz, sapphire, MgO, LiF, CaF ₂ , an organic polymer film such as fluororesin, polyester, polycarbonate, polyethylene, polyethylene terephthalate (PET), or ceramic. Can be used.

The electrode layer 12 is made of, for example, a transparent conductive material such as ITO, ZnO, SnO ₂ , aluminum (Al), gold (Au), platinum (Pt), copper (Cu), silver (Ag), nickel (Ni). It can be formed using a metal such as chromium (Cr). Further, conductive polymers such as PODET / PVS and PODET / PSS, and transparent conductive materials such as titanium oxide, zinc oxide, and tin oxide may be used. These materials can be formed by methods such as vapor deposition, ion plating, and sputtering. The shape of the electrode layer 12 can be appropriately selected according to the shape of a second electrode layer that will be a counter electrode described later. The electrode layer 12 may be provided in contact with the base material 11 or a TFT element or the like may be provided on the base material 11.

  In the first embodiment, when the electrode substrate 10 is a front electrode substrate, the base material 11 and the electrode layer 12 are used to visually recognize the display of characters and the like formed from the electrophoretic ink through the electrode substrate 10. As for, it forms with the material which has translucency.

A structure 15 is erected on the light-transmitting substrate 10 as shown in FIG. The structure 15 can be formed using a resin material such as a PET film. For example, a plurality of cells 16 can be formed by laser processing a synthetic resin such as a PET film having a certain thickness to form a square, hexagon, circle, or the like. Moreover, after forming an insulating layer on the electrode layer 12, the plurality of cells 16 can be formed by patterning the insulating layer using a photolithography method. In addition, it is possible to form a cell 16 composed of a cross-shaped structure 15 by forming a thermoplastic resin on the electrode layer 12 and using a method such as hot embossing.
A plurality of small chambers (cells 16, 16...) Are formed by the insulating structures 15, 15... Standing on the light-transmitting substrate 10. And can be provided in various shapes such as a circle, a rectangle (rectangle, square), and a hexagon. Note that the structure 15 may be referred to as a spacer, a column, a wall, a partition wall, a rib, or the like depending on the shape and purpose.

  The cells 16 formed on the electrode substrate 10 are filled with the electrophoretic ink 20. As a method for filling the electrophoretic ink 20, for example, coating with a die coater or the like, and the electrophoretic ink 20 disposed at an arbitrary position of the electrode substrate is spread by substantially contact with a bar coater, a doctor blade, a comma roll, or the like. Various methods can be used as long as they can fill the cells with ink, such as a printing method using screen printing or a filling method using an ink jet or a dispenser.

The electrophoretic ink 20 used in the present invention is not particularly limited as long as it becomes an electrophoretic ink having a volume resistivity of 1 × 10 ⁷ to 1 × 10 ¹³ Ω · cm when an alternating current of 100 Hz is applied. For example, any material having at least the above physical properties including at least one type of electrophoretic particles and a solvent such as a solvent may be used. In the present invention, the method for measuring “volume resistivity” in electrophoretic ink and an ink sealing film described later refers to a value measured by an impedance measuring device. Further, the “resistance value” in the electrophoretic ink and the ink sealing film described later is calculated by the resistance value = [(volume resistivity x thickness) / area].
As the electrophoretic particles that can be used, for example, colored or colorless (white) inorganic pigment particles, organic pigment particles, polymer fine particles, and the like can be used, and these can be used alone (one type) or two or more types. It can be used by mixing. Moreover, the fine particle by which the lipophilic surface treatment was carried out may be sufficient.
As a specific example, it can be formed with positively charged white particles, negatively charged black particles, and a solvent (solvent) in which these particles are dispersed. As the white particles, white pigments such as titanium oxide, white resin particles, or resin particles colored in white can be used. As the black particles, black pigments such as titanium black and carbon black, resin particles colored in black, and the like can be used. These particles can be arbitrarily used in various colors as long as the contrast can be displayed, and can be a combination of white and red, white and blue, yellow and black, and the like. Alternatively, only one type of charged particle such as only white particles or only black particles may be used.
These electrophoretic particles have an average particle diameter of 0.05 to 20 μm, and particularly preferably an average particle diameter of 0.1 to 10 μm. Further, the total content of these fine particles is preferably 5 to 95% by mass, more preferably 10 to 80% by mass with respect to the total amount of electrophoretic ink.
In addition, as the solvent, for example, hydrocarbon-based, aromatic-based, ester-based, ketone-based, terpene-based, alcohol-based, silicone-based, and fluorine-based solvents may be used alone or in combination of two or more. it can. The content of these solvents can be appropriately selected according to the electrophoretic particles and solvent type to be used, and is preferably contained so as to be 20 to 80%, more preferably 35% with respect to the total amount of the electrophoretic ink. It is desirable to set it to -65%.

The electrophoretic ink 20 may further contain a dispersant and a charge control agent in addition to one or more types of electrophoretic particles and a solvent. Examples of the dispersant that can be used include various commonly used dispersants, surfactants and polymer surfactants such as nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. Examples thereof include, but are not limited to, system surfactants and polymer surfactants. The content of these dispersants is appropriately determined depending on the electrophoretic particles and solvent type to be used, but is preferably 0.01 to 50.0% with respect to the total amount of electrophoretic ink, More preferably, it is contained so that it may become 0.5 to 30%.
As the charge control agent, various types used for electrophoretic display can be used.
The electrophoretic ink 20 used in the present invention suitably combines the above-mentioned characteristics, that is, the volume resistivity when an alternating current of 100 Hz is applied, by suitably combining the types of components constituting the electrophoretic ink and the content of each component. Can be adjusted to an electrophoretic ink of 1 × 10 ⁷ to 1 × 10 ¹³ Ω · cm.
In the present invention, if the volume resistivity when applying an alternating current of 100 Hz to the electrophoretic ink is smaller than 1 × 10 ⁷ Ω · cm, a voltage is not sufficiently applied at 100 Hz, whereas 1 × 10 ¹³ Ω. -If it exceeds cm and the voltage does not drop even when an alternating current of 100 Hz is applied, it becomes almost a direct current, so 1 × 10 ⁷ to 1 × 10 ¹³ Ω · cm is desirable.

When filling the electrophoretic ink 20, it is preferable that a wettability adjusting step for improving the wettability of the electrophoretic ink 20 may be added to the surface of the substrate 10. The electrophoretic ink 20 is sufficiently distributed to the inner walls and corners of the plurality of cells 16, 16... Made of the insulating structure 15, and a gas such as air is supplied to the plurality of cells made of the insulating structures 15, 15. This is a preferred process for expelling from within the cells 16, 16.
As this wettability adjustment step, for example, solvent treatment, acid treatment, alkali treatment, ozone treatment, plasma treatment, corona discharge treatment, UV treatment, UV ittro treatment, laser treatment, treatment with electron beam, treatment by ion implantation method, Ion beam treatment, ion irradiation treatment, primer treatment, surfactant treatment, sputtering treatment, (physical vapor deposition), CVD (chemical vapor deposition), polymer layer formation and inorganic layer formation, etc. Is mentioned. These may be used in combination, and are not limited to these.
Further, in order to remove the contamination on the substrate surface in advance, the wettability can be adjusted more effectively by combining treatment such as washing with a solvent, for example, washing with alcohol.

  Further, when the electrophoretic ink 20 is filled, it is dissolved in the electrophoretic ink 20 before filling, at the time of filling, or after filling in order to prevent bubbles such as air from entering or remaining in the display area as much as possible. It is preferable to sufficiently deaerate and remove the gas or the air that is entrained (the environmental atmosphere is a reduced pressure environment). Specifically, the filling step is performed in a reduced pressure environment or after being applied, it is left in a reduced pressure environment. As a result, the gap between the electrophoretic ink 20 and the replacement of the air in the cell with the electrophoretic ink 20 can be promoted, and the possibility that air bubbles remain in the panel can be reduced. Since the bubbles are prevented from being mixed in between the films (after sealing) to become a stop film, display irregularities, display defects, deterioration due to bubble growth, etc. are suppressed, and stable display quality over a long period of time. It is possible to obtain an electrophoretic display medium sheet having an electrophoretic display medium and an electrophoretic display medium.

  As a method of deaeration before filling, for example, a method of stirring the electrophoretic ink 20 with a stirring rod, a method of heating, a method of stirring while warming, a method using ultrasonic waves, a method using reduced pressure, or a method using centrifugal force Examples thereof include a method and a method by adding additives such as an antifoaming agent, but are not limited thereto. Furthermore, these methods can be used in combination.

  After the electrophoretic ink 20 is filled, as shown in FIG. 2 (c), the electrode substrate 10 is contacted with the structures 15 and 15 of the cells 16 and 16 which are the outermost peripheral portions in the display area. Seal portions 16 and 16 are formed. As a method of forming the seal portions 16 and 16, a thermoplastic, thermosetting or photo-curing precursor material or the like is used in various printing methods [screen printing method, letterpress printing method, intaglio printing (gravure) printing], using a dispenser. It can be formed by a coating method. The height of the seal portions 16, 16 when forming the seal portions 16, 16 is set to be about 0.01 to 2 mm higher than the height of the insulating structures 15, 15... .5mm higher. Moreover, the seal parts 16 and 16 of this embodiment were formed by dripping UV curable resin with a dispenser.

In this embodiment, as shown in FIG. 2 (d), each structure 15 includes an ink sealing film 30 that is disposed opposite to the electrode substrate 10 filled with the electrophoretic ink 20 and seals the electrophoretic ink 20. The target electrophoretic display medium sheet A can be obtained by pasting on the upper surfaces of the seal portions 26 and 26.
The ink sealing film 30 to be used is particularly a film that has a resistance value equal to or less than five times the resistance value of the electrophoretic ink when an alternating current of 100 Hz or more that is disposed opposite to the substrate and seals the electrophoretic ink is applied. Without limitation, for example, polyvinylidene chloride film, polyvinylidene fluoride film, film containing vinylidene chloride or vinylidene fluoride as a constituent unit, and film containing vinylidene chloride or vinylidene fluoride as a polymer blend, polyvinyl chloride film, chloride The film etc. which contain vinylidene as a structural unit can be mentioned.
Preferably, the polyvinylidene fluoride film is preferably used as the ink sealing film 30 from the viewpoint that the volume resistivity decreases at a lower frequency and the effects of the present invention are further exhibited.
This polyvinylidene chloride film, polyvinylidene fluoride film, film containing vinylidene chloride or vinylidene fluoride as a constituent unit, film containing vinylidene chloride or vinylidene fluoride as a polymer blend has high gas barrier properties against oxygen, water vapor, etc. Light transmittance, high dielectric constant, durability, and preferably a polyvinylidene chloride single film, polyvinylidene fluoride single film, vinylidene chloride or vinylidene fluoride as a constituent unit A copolymer film having a vinylidene chloride content ratio of 50% by mass or more, and a polymer blend having a vinylidene chloride content ratio or a vinylidene fluoride content ratio of 50% by mass or more is preferable. More preferably a film containing 70 mass% or more as a de.
Further, if the resistance value when an alternating current of 100 Hz or more is applied to the ink sealing film 30 is more than 5 times the resistance value of the electrophoretic ink, the resistance value is not applied to the ink and display is obtained. Since there is no, 5 times or less is desirable. When this resistance value is compared, it is desirable that the ink sealing film is lower than the ink, and it is more desirable that the numerical value is 1 or less, and the lower the value, the better.

The copolymer film containing vinylidene chloride as a structural unit that can be used may be a film made of a copolymer using vinylidene chloride and a monomer copolymerizable with vinylidene chloride. As the monomer, any monomer can be used as long as it is a substance copolymerizable with vinylidene chloride, and one or more monomers can be used.
Examples of the monomer copolymerizable with vinylidene chloride include vinyl chloride; acrylic acid esters such as methyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; methyl metaacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, and lauryl. Methacrylates such as acrylates,
And the like.
Among these, a vinylidene chloride / vinyl chloride copolymer film and a vinylidene chloride / acrylonitrile copolymer film are particularly desirable.
The vinylidene chloride / vinyl chloride copolymer that can be used is represented by the following formula (I), and in this copolymer, the vinylidene chloride content is preferably 50% by mass.

The copolymer film containing vinylidene fluoride as a structural unit that can be used is a homopolymer of vinylidene fluoride, a copolymer of vinylidene fluoride and other monomers, or a modified product of the above copolymer. Among them, polyvinylidene fluoride which is a homopolymer of vinylidene fluoride is particularly preferable.
Examples of the copolymer of vinylidene fluoride and other monomers include, for example, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, and vinylidene fluoride-chlorotrifluoroethylene copolymer. , Vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, or a copolymer obtained by further copolymerizing another ethylenically unsaturated monomer with the above exemplified copolymer. More specific examples of the copolymerizable ethylenically unsaturated monomer include, for example, acrylic ester, methacrylic ester, vinyl acetate, acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride, butadiene, styrene, N- Examples include vinyl pyrrolidone, N-vinyl pyridine, glycidyl methacrylate, hydroxyethyl methacrylate, and methyl vinyl ether.
In addition, in the polyvinylidene fluoride resin that is a modified product of the above-mentioned copolymer, examples of the modified product include those modified with an alcoholic hydroxyl group, a carboxyl group, or the like. The alcoholic hydroxyl group or carboxyl group can be introduced by substituting another group with an alcoholic hydroxyl group or carboxyl group or by copolymerizing a monomer having an alcoholic hydroxyl group or carboxyl group.

The film containing the vinylidene chloride or vinylidene fluoride as a polymer blend may be any film that can be polymerized as a polymer blend of vinylidene chloride or vinylidene fluoride, and can be copolymerized with the vinylidene chloride or vinylidene fluoride. Monomer components can be used.
Furthermore, each single film, copolymer film, or film containing a polymer blend containing vinylidene chloride or vinylidene fluoride as a constituent unit preferably has a weight average molecular weight of 30,000 to 200,000, preferably 70,000 to 150,000. Are more preferred. The content of vinylidene chloride contained as a vinylidene chloride copolymer and polymer blend, the content of vinylidene fluoride contained as a vinylidene fluoride copolymer and polymer blend, and the weight average molecular weight are in terms of extrudability, gas barrier properties, mechanical properties, etc. The above range is preferred. The single film, copolymer film, and film included as a polymer blend used in the present invention can be obtained by a known suspension polymerization method, emulsion polymerization method, solution polymerization method or the like.
Moreover, what contained various additives can be used for each said film to be used. As various additives, plasticizers such as phthalate ester, adipate ester, citrate ester, phosphate ester, dibutyl sebacate (DBS), acetyltributyl citrate (ATBC) with suitable contents; epoxidized soybean oil Epoxy compounds such as epoxidized linseed oil, bisphenol A diglycidyl ether, epoxidized polybutadiene, epoxidized octyl stearate; antioxidants such as vitamin E, butylhydroxytoluene (BHT), alkyl thiodipropionate; pyrophosphoric acid Thermal stabilizers such as soda, sodium tripolyphosphate, disodium ethylenediaminetetraacetate (EDTA-2Na), magnesium oxide; various light stabilizers; various lubricants; various colorants, flame retardants, ultraviolet absorbers, etc. it can. Some of these additives may be added simultaneously with or during the polymerization of the vinylidene chloride copolymer.
Preferably, each of the above films contains 1 to 30% by mass of the plasticizer in the film from the viewpoint of imparting flexibility to the film.

The thickness of each of the films 30 that can be used is preferably 0.1 to 20 μm, more preferably 1 to 15 μm, from the viewpoint of reducing the resistance value and securing the gas barrier property.
If the thickness of the film 30 is less than 0.1 μm, the gas barrier property is insufficient and the solvent in the ink evaporates. On the other hand, if the thickness exceeds 20 μm, the resistance value of the ink sealing film increases. Therefore, the voltage is not sufficiently applied to the electrophoretic ink, and the display performance is deteriorated.

  As an adhesion method, an ink sealing film 30 having the above characteristics that seals the electrophoretic ink disposed on the electrode substrate 10 filled with the electrophoretic ink 20 is attached to the upper surface of each structure 15 and the seal portions 26 and 26. For example, after one end of the ink sealing film 30 is aligned, the ink sealing film 30 is bonded to the upper surface of each structure 15 and the seal portions 26 and 26 by passing between rollers disposed opposite to each other. 1 is cured by UV irradiation to obtain an electrophoretic display medium sheet A shown in FIG.

In the present invention, an electrophoretic display medium can be produced by laminating the obtained electrophoretic display medium sheet A on an arbitrary substrate by adhesion or the like, and an electrophoretic display device can be obtained by providing a control unit or the like. be able to.
As an arbitrary substrate, for example, a transparent resin film or transparent glass formed of a transparent conductive material such as ITO by a coating method, an ion plating method, a vapor deposition method such as a sputtering method, or a resin A non-conductive material surface such as a film, a resin plate, glass, ceramics, or the like formed with a conductive material film (layer) such as metal, or a metal plate can be used.
Depending on the use (use application, rewriting method, etc.) of the electrophoretic display medium, another light transmissive electrode, non-light transmissive electrode, resin film, resin, wood, metal, ceramics, paper, cloth, etc. It is also possible to bond with glass.
Moreover, when a resin film is used for the substrate, the effect can be increased by bonding a resin film having a solvent permeation suppressing effect or a gas permeation suppressing effect or other base material.
In addition, in order to increase the strength of the electrophoretic display device, it is possible to attach and reinforce another base material, or to attach paper or cloth as another base material for decoration of the display device.

In the electrophoretic display medium sheet A according to the first embodiment of the present invention configured as described above, the substrate 10 having light transmissivity, the electrophoretic ink 20, and the volume specific resistance when an alternating current of 100 Hz is applied. The resistance value when the electrophoretic ink 20 of 1 × 10 ⁷ to 1 × 10 ¹³ Ω · cm and an alternating current of 100 Hz or higher that is disposed opposite to the substrate and seals the electrophoretic ink is applied is the resistance value of the electrophoretic ink. By having the ink sealing film 30 that is 5 times or less and the structure 15 formed between the substrate 10 and the ink sealing film 30, the ink sealing film that seals the electrophoretic ink is the electrophoretic ink. An electrophoretic display medium sheet excellent in structural durability and display durability of an electrophoretic display medium, and an electrophoretic display medium using the same, because it is composed of a film having a characteristic of 5 times or less the resistance value It is possible to obtain. In addition, the electrophoretic display device obtained from this electrophoretic display medium sheet realizes high contrast display, can display contrast with high reliability even during repeated display, and has excellent responsiveness and display. Deterioration of characteristics is extremely small.
In particular, the ink sealing film 30 is a film having a characteristic that is not more than 5 times the resistance value of the electrophoretic ink, and has a high gas barrier property, light transmittance, high dielectric constant, durability against oxygen, water vapor, and the like. If the polyvinylidene chloride or polyvinylidene fluoride having a film, a film containing vinylidene chloride or vinylidene fluoride as a structural unit, or a vinylidene chloride or vinylidene fluoride film as a polymer blend, the structural durability of the electrophoretic display medium It is possible to obtain an electrophoretic display medium sheet having further excellent display durability and an electrophoretic display medium using the same.

3A to 3D are schematic diagrams for explaining the manufacturing process of the electrophoretic display medium sheet according to the second embodiment of the present invention for each process. In the following embodiments (FIGS. 3 to 10) of the second embodiment, the same configurations as those of the first embodiment are denoted by the same reference numerals on the drawings, and the description thereof is omitted.
The electrophoretic display medium sheet B of the second embodiment of the present invention is obtained after obtaining the electrophoretic display medium sheet in the same manner as in the first embodiment (FIGS. 2A to 2D). As shown in FIG. 3 (d), a base film 35 is laminated on the ink sealing film 30. Specifically, a 5 μm-thick vinylidene chloride-acrylonitrile copolymer film and a 100 μm PET film are laminated by a laminator.
In this electrophoretic display medium sheet B, an ink sealing film that is thin and firm can be laminated, and an electrophoretic display sheet is obtained by removing the release film.

4 and 5 are a schematic longitudinal sectional view showing an electrophoretic display medium sheet according to a third embodiment of the present invention, and a schematic drawing for explaining the manufacturing process of the electrophoretic display medium sheet for each step.
The electrophoretic display medium sheet C according to the third embodiment of the present invention is different from the first embodiment in that the structure 15 is erected on an electrode substrate 10 as shown in FIG. This is different from the first embodiment in that the adhesive layer 17 is formed on the upper surface of the body 15 and the ink sealing film 30 is bonded.
The adhesive layer 17 can be formed by using various adhesives such as a thermosetting adhesive, a thermoplastic adhesive, and a photocurable adhesive, and it is particularly preferable to use a thermoplastic adhesive. The thermoplastic adhesive can fix the adhesive only to the upper surface of the structure 15 by forming an adhesive layer 17 on the upper surface of the structure 15 in a state of being melted or softened by heating and then cooling. . This makes it possible to suppress the inflow of the adhesive into the cell. Furthermore, since it can be melted or softened by heating again after filling of the electrophoretic ink 20, it is preferable for bonding with the ink sealing film 30.

  Moreover, when using a thermosetting adhesive or a photocurable adhesive, it is preferable to form the adhesive layer 17 so that the inflow of the adhesive from the upper surface of the structure 15 into the cell can be suppressed. For example, the heat is applied to the upper surface of the structure 15 with a minimum amount of heat or UV irradiation so that the adhesive can be fixed, and then cured by heating or UV irradiation again when bonded to the ink sealing film 30. The method of making it adhere | attach and harden can be mentioned.

In the third embodiment, the adhesive layer 17 can be formed by using various methods such as gravure printing, screen printing, ink jetting, and transfer according to the characteristics of the adhesive to be used. In particular, a transfer method is used. It is preferable. In the present embodiment, a transfer method is used. For example, a part of the adhesive on the surface of the base material is peeled off after the base material on which the adhesive is formed is brought into contact with the upper surface of the structure 15. Can be transferred onto the upper surface of the structure 15. This is because the adhesive layer 17 can be selectively and easily formed on the upper surface of the structure 15 by using the transfer method.
In the electrophoretic display medium sheet C, the ink sealing film 30 can be further firmly fixed to the upper surfaces of the structural bodies 15, 15... And the upper surfaces of the seal portions 16, 16. And an electrophoretic display medium sheet having excellent display durability and an electrophoretic display medium using the same.

6 and 7 are a schematic longitudinal sectional view showing a sheet for electrophoretic display medium according to a fourth embodiment of the present invention, and a schematic drawing for explaining the manufacturing process of the sheet for electrophoretic display medium for each step.
The electrophoretic display medium sheet D of the fourth embodiment of the present invention is similar to the first embodiment in ink sealing as in the first embodiment, as shown in FIGS. 6 and 7A. After the structure 15 is erected on the film 30, the electrophoretic ink 20 is filled and the seal portions 16 and 16 are formed, and then the light-transmitting substrate 10 is bonded and electrophoretic displayed in the same manner as the film 30 is bonded. A medium sheet is produced.

  In this electrophoretic display medium sheet D, after the structure 15 is erected on the film 30 having the same configuration as the ink sealing film, the electrophoretic ink 20 is filled, and the seal portions 16 and 16 are formed. The light-transmitting substrate 10 is bonded to the transparent electrode when the structure is erected, and a sheet for an electrophoretic display medium having high reflectivity and an electrophoretic display medium using the same are provided. Can be obtained.

FIG. 8 is a schematic diagram for explaining the manufacturing process of the electrophoretic display medium sheet according to the fifth embodiment of the present invention for each process.
An electrophoretic display medium sheet E according to a fifth embodiment of the present invention has a base film 35 laminated on the film 30 of the fourth embodiment as shown in FIG. This is the only difference from the fourth embodiment.
As the base film 35, for example, a PET film having a thickness of 100 μm can be mentioned, and as a laminating method, a laminator can be used.
In the electrophoretic display medium sheet E, since the base film 35 is laminated on the film 30, the structure can be erected on the thin film 30 without the stiffness, and the structure is erected. Since there is no damage to the transparent electrode, a sheet for an electrophoretic display medium having high reflectivity and an electrophoretic display medium using the same can be obtained.

FIG. 9 is a schematic longitudinal sectional view showing an electrophoretic display medium sheet according to a sixth embodiment of the present invention.
The electrophoretic display medium sheet F according to the sixth embodiment of the present invention is different from the fourth embodiment in that the structure body is provided before the structure body 15 is erected on the ink sealing film 30 of the fourth embodiment. From the point of firmly fixing 15 on the ink sealing film 30, an adhesive layer 17 similar to that of the third embodiment is selected on the lower surface of the structure 15 by a transfer method or the like at the position where the structure 15 is erected. Is formed.
In the electrophoretic display medium sheet F, since the structures 15 and 15 can be firmly fixed on the ink sealing film 30, the electrophoretic display medium is further excellent in structural durability and display durability of the electrophoretic display medium. Sheet and an electrophoretic display medium using the same can be obtained.

FIG. 10 is a schematic diagram for explaining the manufacturing process of the electrophoretic display medium sheet according to the seventh embodiment of the present invention for each process.
In the electrophoretic display medium sheet G of the seventh embodiment of the present invention, the electrode substrate 10 is firmly fixed to the upper surface of the structure 15 as shown in FIG. In view of this point, the adhesive layer 19 is selectively formed on the upper surface of the structure 15 by the transfer method or the like on the upper surface of the structure 15 in the same manner as in the third embodiment.
In this electrophoretic display medium sheet G, since the electrode substrate 10 can be firmly fixed to the upper surfaces of the structures 15 and 15, the electrophoretic display medium sheet is further excellent in structural durability and display durability. In addition, an electrophoretic display medium using the same can be obtained.

The present invention is configured as described above, but is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea of the present invention.
For example, when a substrate is laminated on a film of an electrophoretic display medium sheet, an adhesive layer for improving adhesion may be provided.

  Next, examples suitable for carrying out the present invention will be shown, but the present invention is not limited thereto.

(Based on Example 1, FIG. 1 and FIG. 2)
Through the following steps, an electrophoretic display medium sheet and an electrophoretic display medium were obtained.
Step of forming a plurality of cells made of an insulating structure on an electrode substrate A 125 μm-thick PET sheet (11 ×) formed by forming an ITO film, which is a transparent material, to have a surface resistance of about 100Ω / □ as an electrode substrate 10 cm) (hereinafter referred to as “ITO-PET”).
On this first electrode substrate, a photosensitive resin sheet made of an acrylic resin is bonded, UV exposure, alkali development, and a plurality of lattice cells (height 0.05 mm) made of an insulating structure. A cell size of 0.5 × 0.5 mm and an aperture ratio of 80% was formed in a 9 × 9 cm range of the PET film.

2) Step of filling the cell with electrophoretic ink Composition of electrophoretic ink used:
It is 82% by mass of octane, 10% by mass of titanium oxide particles, 5% by mass of acrylic particles containing carbon black, and 3% by mass of hydroxyethylamine, and has a volume resistivity of 1 × 10 ¹⁰ Ω · cm when an alternating current of 100 Hz is applied. It was. The measurement was performed using an impedance measuring device (product name: FRA5087, manufactured by NF Circuit Block) (hereinafter the same).
The electrophoretic ink was filled into the cell by silk printing.
3) Step of forming a seal portion A UV curable resin was dropped onto the outer peripheral portion (display area) of the cell using a dispenser to form a seal portion (height 0.5 mm, width 5 mm).

4) Step of bonding electrode substrate and ink sealing film A 10 μm vinylidene chloride / vinyl chloride copolymer film (11 × 10 cm) was used as the film of the ink sealing film 30. The vinylidene chloride / vinyl chloride copolymer film had a vinylidene chloride content of 80%. Further, when the volume resistivity of the vinylidene chloride / vinyl chloride copolymer film was measured using an impedance measuring device, it was 5 × 10 ¹⁰ Ω · cm at 100 Hz.
After aligning one end of the ink sealing film to the electrode substrate filled with the electrophoretic ink, it is bonded by passing between rollers installed opposite to each other, and then cured by UV irradiation to the seal part, An electrophoretic display medium sheet was obtained.
The ink area Si at this time was Si = 9 × 9 × 0.8 = 64.8 cm ² , and the ink thickness Ti was Ti = 0.05 mm, so the ink resistance value Ri was calculated. Then, Ri = 7.7 × 10 ⁵ Ω.
Similarly, the area Sf of the ink sealing film touching the ink is Sf = 9 × 9 × 0.8 = 64.8 cm ² , and the thickness Tf of the ink sealing film is Tf = 10 μm. Therefore, when the resistance value Rf of the ink sealing film was calculated, Rf = 7.7 × 10 ⁵ Ω, and the resistance value Rf of the ink sealing film was about 1.0 times the resistance value Ri of the ink.

Bubbles were not mixed in the display area of the obtained electrophoretic display medium sheet, and the distance between the electrode and the ink sealing film was uniform.
Further, an electrode substrate (a copper film is laminated on a polyimide film and a pattern is formed by etching) is bonded to the obtained electrophoretic display medium sheet, and white display is obtained by applying +50 v 50 times at a cycle of 100 Hz. It was confirmed that black display can be obtained by applying -50v 50 times in the cycle, and that high contrast monochrome display is possible. The display was obtained here: a) When a 100 Hz alternating current is applied, the resistance value of the ink sealing film is not more than 5 times the resistance value of the electrophoretic ink, and in this embodiment, a film that is substantially the same is employed, b C) 100 Hz alternating current applied, c) electrophoretic ink volume resistivity of 1 × 10 ¹⁰ Ω · cm, 100 Hz alternating current volume electrophoretic ink volume resistivity exceeding 1 × 10 ¹³ Ω · cm When the voltage is higher, the ink voltage does not decrease and is the same as the direct current application. Therefore, the resistance value of the ink sealing film does not decrease and a sufficient voltage is not applied to the ink. In addition, when the volume resistivity of the electrophoretic ink is 1 × 10 ⁷ to 1 × 10 ¹⁰ Ω · cm, the voltage is appropriately lowered and ink is sealed by applying an alternating current of 100 Hz to the ink and the ink sealing film. This is because the resistance value of the film is lowered and a voltage capable of driving the electrophoretic ink is sufficiently applied. When the volume resistivity of the electrophoretic ink was lower than 1 × 10 ⁷ Ω · cm, the voltage of the ink immediately dropped, and display was impossible.
As described above, in the present invention, the electrophoretic display medium sheet having the above-described configuration has an electrophoretic ink having a volume resistivity of 1 × 10 ⁷ to 1 × 10 ¹³ Ω · cm when an alternating current of 100 Hz is applied to the substrate. The electrophoretic ink can be driven by using an ink sealing film in which the resistance value when applying an alternating current of 100 Hz or more that is disposed so as to seal the electrophoretic ink is 5 times or less than the resistance value of the electrophoretic ink. The voltage was sufficiently applied, and a high contrast monochrome display was obtained.
Further, when the obtained electrophoretic display medium was evaluated for display performance after being left for 1 month under conditions of a) 50 ° C. drying conditions and b) 50 ° C. and 80% humidification, both conditions were evaluated. Thus, an electrophoretic display medium in which display characteristics did not change from the initial stage and display resistance to display degradation was obtained. In addition, no bubble was observed in the cell.

(Example 2, conforming to FIG. 3)
In Example 1 above, the film was laminated to a harder film and then laminated to the substrate coated with electrophoresis ink. Specifically, a PET film having a thickness of 100 μm was laminated on a polyvinylidene fluoride single film (10 × 10 cm) having a thickness of 5 μm by a laminator. When the volume resistivity of the polyvinylidene fluoride film was measured using an impedance measuring device, it was 4.5 × 10 ¹⁰ Ω · cm at 100 Hz, and the resistance value of the ink sealing film was the same as in Example 1 above. When calculated, the resistance value of the film was about 0.45 times the resistance value of the ink.

(Example 3, according to FIGS. 4 and 5)
In Example 1 above, a thermoplastic adhesive diluted with a solvent (hot melt resin, Byron 55ss, manufactured by Toyobo Co., Ltd.) was applied to the structure formed on ITO-PET with a film thickness of 12 μm using a comma roll. Dried. Next, the PET film on which the thermoplastic adhesive layer is formed and the first electrode substrate on which the structure is formed are passed through a thermal laminator at 120 ° C. and peeled off while being heated. A part of the thermoplastic adhesive layer formed on the film was transferred to the upper surface of the structure. The film thickness of the thermoplastic adhesive layer formed on the upper surface of the structure was 6 to 8 μm.
Subsequently, an ink sealing film was bonded in the same manner as in Example 1 to obtain an electrophoretic display medium sheet and an electrophoretic display medium.

(Conforms to Example 4, FIGS. 6 and 7)
An electrophoretic display medium was obtained by the following steps.
Step of forming a plurality of cells made of an insulating structure on the ink sealing film A 15 μm vinylidene chloride / acrylonitrile copolymer film (11 × 10 cm) was used as the ink sealing film. The vinylidene chloride / acrylonitrile copolymer film had a vinylidene chloride content of 80%. When the volume resistivity of the vinylidene chloride / acrylonitrile copolymer film was measured using an impedance measuring device, it was 9.5 × 10 ¹⁰ Ω · cm at 100 Hz, and this resistance value was calculated in the same manner as in Example 1 above. Then, it was 2.2 × 10 ⁶ Ω.
A photosensitive resin sheet made of an acrylic resin is bonded to the ink sealing film, exposed to UV, and alkali-developed to form a plurality of lattice-like cells (height 0.05 mm, cell having an insulating structure) In the range of 9 × 9 cm of the ink sealing film).
) Was formed.

2) Step of filling the cell with electrophoretic ink Composition of electrophoretic ink used:
Dodecane 57% by mass, titanium oxide particles 20% by mass, carbon black-containing acrylic particles 20% by mass, hydroxyethylamine 3% by mass, and the volume resistivity when 1.2 Hz is applied is 1.2 × 10 ¹⁰ Ω · cm. Yes, when this resistance value was calculated in the same manner as in Example 1, it was 9.3 × 10 ⁵ Ω.
The electrophoretic ink was filled in the cell with a die coater.
3) Step of forming a seal portion A UV curable resin was dropped onto the outer peripheral portion of the display area using a dispenser to form a seal portion (height 0.5 mm, width 5 mm).

4) Step of bonding to electrode substrate A 125 μm thick PET sheet (11 × 10 cm) in which an ITO film, which is a transparent material, was formed to have a surface resistance of about 100 Ω / □ was used as the electrode substrate.
After aligning one end of the electrode substrate to the ink sealing film filled with the electrophoretic ink, it is bonded by passing between rollers installed opposite to each other, and then cured by UV irradiation on the seal part, An electrophoretic display medium sheet was obtained. When the resistance value of the ink sealing film was calculated in the same manner as in Example 1, it was about 2.38 times the resistance value of the ink.

(Example 5, according to FIG. 8)
In Example 4 above, the films were laminated to a harder film and then laminated to the substrate coated with the electrophoretic ink. Specifically, a 100 μm thick PET film was laminated with a laminator.

(Example 6, conforming to FIG. 10)
In Example 4 above, a thermoplastic adhesive diluted with a solvent (hot melt resin, Byron 55ss, manufactured by Toyobo Co., Ltd.) was applied to the structure formed on the ink sealing film with a film thickness of 12 μm using a comma roll. Later it was dried. Next, the PET film on which the thermoplastic adhesive layer is formed and the electrode substrate on which the structure is formed are passed through a thermal laminator at 120 ° C. and then peeled off while being heated to form a PET film. A portion of the resulting thermoplastic adhesive layer was transferred to the top surface of the structure. The film thickness of the thermoplastic adhesive layer formed on the upper surface of the structure was 6 to 8 μm.
Next, an ink sealing film was bonded in the same manner as in Example 4 to obtain an electrophoretic display medium sheet and an electrophoretic display medium.

(Performance evaluation of electrophoretic display media of Examples 2 to 6)
Bubbles were not mixed in the display area of each electrophoretic display medium sheet obtained in Examples 2 to 6, and the distance between the electrode and the ink sealing film was uniform.
Furthermore, an electrode substrate is bonded to each electrophoretic display medium sheet obtained in Examples 2 to 6, and white display is applied by applying +50 v 50 times at a cycle of 100 Hz, and −50 v is applied 50 times at a cycle of 100 Hz. By doing so, it was possible to obtain a black display, and it was confirmed that high contrast monochrome display was possible.
Further, when the obtained electrophoretic display medium was evaluated for display performance after being left for 1 month under conditions of a) 50 ° C. drying conditions and b) 50 ° C. and 80% humidification, both conditions were evaluated. Thus, an electrophoretic display medium in which display characteristics did not change from the initial stage and display resistance to display degradation was obtained. In addition, no bubble was observed in the cell.

DESCRIPTION OF SYMBOLS 10 Electrode board 11 Base material 12 Electrode layer 15 Structure 16 Cell 17 Adhesive layer 20 Electrophoresis ink board 26 Seal part 30 Film

  Sheets for electrophoretic display media and electrophoretic display media using the same according to the present invention include electronic papers such as electronic books and electronic newspapers, billboards such as signboards, posters, and blackboards, electronic price tags, electronic shelf labels, electronic advertisements, and moniles. It can be suitably used for applications such as a display unit of equipment.

Claims (9)

A substrate having optical transparency, an electrophoretic ink having a volume specific resistance of 1 × 10 ⁷ to 1 × 10 ¹³ Ω · cm when an alternating current of 100 Hz is applied, and the electrophoretic ink which is disposed opposite to the substrate and sealed. It has an ink sealing film in which a resistance value when an alternating current of 100 Hz or more is applied is five times or less of a resistance value of electrophoretic ink, and a structure formed between the substrate and the ink sealing film. An electrophoretic display medium sheet. The ink sealing film Gapo Li vinylidene chloride film, polyvinylidene fluoride film, a film containing as a structural unit of vinylidene chloride or vinylidene fluoride, and at least one selected vinylidene chloride or vinylidene fluoride from the film containing the polymer blend The sheet for electrophoretic display media according to claim 1, wherein:   The electrophoretic display medium sheet according to claim 1, wherein the ink sealing film contains a plasticizer.   The electrophoretic display medium sheet according to claim 1, wherein the structure is formed on a substrate.   The electrophoretic display medium sheet according to claim 4, wherein the structure is laminated with the ink sealing film via an adhesive layer.   The electrophoretic display medium sheet according to claim 1, wherein the structure is formed on the ink sealing film.   The sheet for electrophoretic display media according to claim 6, wherein the structure is laminated with the substrate through an adhesive layer.   The electrophoretic display medium sheet according to claim 5, wherein the adhesive layer is a hot-melt adhesive layer. An electrophoretic display medium comprising a substrate laminated on an ink-sealing film of the electrophoretic display medium sheet according to claim 1.