WO2013024735A1 - Electrophoretic display sheet and electrophoretic display medium using same - Google Patents

Abstract

The purpose of the present invention is to provide the following: a low-cost, high-quality electrophoretic display sheet that is highly durable, exhibits excellent display characteristics, and can be produced with high yield; and an electrophoretic display medium using said electrophoretic display sheet. This electrophoretic display sheet (A) can be obtained, for example, by: using diving walls (15) comprising an insulating material to form a cell structure (20) on a light-transmitting electrode surface (11) formed on a light-transmitting substrate material (10); filling said cell structure (20) with an electrophoretic ink (25); and bonding a film (35) on which an adhesive sealing layer or pressure-sensitive adhesive sealing layer (30) is formed to the top surface of the cell structure (20).

Description

Electrophoretic display sheet and electrophoretic display medium using the same

The present invention relates to an electrophoretic display sheet and an electrophoretic display medium using the same.

In recent years, there has been an increasing demand for display devices with low power consumption, thin and light weight, flexibility, etc. As one of them, electronic paper is attracting attention. An electrophoretic display device using electrophoretic ink or the like is known as one of such electronic papers.

In general, an 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.
This 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 printed materials, consuming less power, and having memory properties for display.

In such an electrophoretic display device, an electrophoretic display device using an electrophoretic display sheet (front plane) is known in which the electrophoretic display sheet is attached to various electrode substrates (back planes). The electrophoretic display sheet used does not need to form partition walls (ribs) directly on the backplane (TFT, segment substrate, etc.), and can be used in any combination with various backplanes. It can be mass-produced on a roll-to-roll basis, can be produced without matching the size of the backplane, and can be cut and used as needed. This electrophoretic display sheet has a configuration in which an electrophoretic ink layer is formed on a light-transmitting electrode surface formed on a light-transmitting substrate material.

In an electrophoretic display device having such a structure, for example, a sealing method for manufacturing an electrophoretic display, in which a) filling an array of microcups with an electrophoretic fluid; b) accommodating in a cell The electrophoretic fluid is overcoated with a sealing composition (sealing liquid) that contains a thermoplastic elastomer and a solvent or solvent mixture that is immiscible with the electrophoretic fluid and has a specific gravity lower than that of the electrophoretic fluid. And c) a method including drying a sealing composition (sealing liquid) so as to form a sealing layer is known (see, for example, Patent Document 1).
However, in this manufacturing method, the sealing liquid is cured after overcoating such as application or spraying. However, when the electrophoretic fluid has a lower specific gravity than the sealing composition, the surface is cured before the sealing liquid is cured. There is a problem that it cannot be sealed because it sinks.

On the other hand, in order to provide a manufacturing method of an image display medium with excellent molding accuracy, low manufacturing cost, low density unevenness, high density, high resolution, and at least two opposing substrates, A method of manufacturing an image display medium having a partition wall provided between the substrates, wherein an end width a on the image display side and an end width b on the opposite side of the image display side in the cross section of the partition wall There is known a method for manufacturing an image display medium (see, for example, Patent Document 2), which includes a step of integrally forming a partition so that the ratio (a / b) is 0.8 or less. .
In this manufacturing method, the ratio (a / b) between the end width a and the end width b on the image display side of the partition provided between at least two opposing substrates is set to 0.8 or less. In the present invention, the width of the end portion is narrowed toward the image display side (front plate side) to ensure the aperture ratio on the image display side and the strength as a partition wall. The electrophoretic display sheet (front plane) is affixed to the back plane without directly forming partition walls on various electrode substrates such as TFT and segment substrates, and the end width of the partition walls is opposite to the image display side. It is narrowed toward the back plate side, which is the side, to further improve the sealing performance of the electrophoretic ink, and the technical ideas (configuration and operational effects) of both are different.

JP 2005-509690A (Claims, Examples, FIG. 4, FIG. 5 etc.) Japanese Unexamined Patent Publication No. 2003-208107 (Claims, Examples, FIG. 1, FIG. 7, etc.)

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and is intended to solve this problem. A high-quality electrophoretic display sheet excellent in durability, display characteristics, and productivity at low cost, and electrophoretic display using the same The purpose is to provide a medium.

As a result of intensive studies to solve the above-described conventional problems, the inventor of the present invention has a cell-like structure configured by partition walls made of an insulating material on a light-transmitting electrode surface formed on a light-transmitting substrate material. Forming the body, filling the inside of the cellular structure with the electrophoretic ink, and bonding the film having a specific structure to the electrophoretic ink layer, it is found that the target electrophoretic display sheet can be obtained, Further, the inventors have found that the electrophoretic display medium can be obtained by laminating the electrophoretic display sheet on an arbitrary substrate, and the present invention has been completed.

That is, the present invention resides in the following (1) to (16).
(1) A cellular structure composed of partition walls made of an insulating material is formed on a transparent electrode surface formed on a transparent substrate material, and electrophoretic ink is filled in the cellular structure. An electrophoretic display sheet, wherein a film on which a sealing adhesive layer or a sealing adhesive layer is formed is bonded to the electrophoretic ink layer.
(2) The partition wall of the insulating material is characterized in that the width of the short axis of the partition wall decreases from the light-transmitting electrode surface side toward the sealing adhesive layer or the sealing adhesive layer (1 ) The electrophoretic display sheet described in the above.
(3) The width of the short axis of the partition wall on the side of the sealing adhesive layer or the sealing adhesive layer is smaller than the particle diameter of at least one of the electrophoretic particles contained in the electrophoretic ink layer. The electrophoretic display sheet described in 1.
(4) The electrophoretic display sheet according to any one of (1) to (3) above, wherein a gap smaller than at least one of the particle diameters is formed in the partition wall of the insulating material. .
(5) A cellular structure composed of partition walls made of an insulating material is formed on a transparent electrode surface formed on a transparent substrate material, and electrophoretic ink is filled in the cellular structure. Then, after the film on which the sealing precursor layer was formed was bonded to the electrophoretic ink layer, the sealing precursor layer was cured to form a sealing layer, thereby sealing the electrophoretic ink layer. Then, the electrophoretic display sheet, wherein the film is peeled from the sealing layer.
(6) The electrophoresis according to (5), wherein the partition wall of the insulating material has a width of a short axis of the partition wall becoming narrower from the light-transmitting electrode surface side toward the sealing layer. Display sheet.
(7) The electrophoresis according to (6), wherein the width of the minor axis of the partition wall on the sealing adhesion layer side is smaller than the particle diameter of at least one of the electrophoretic particles contained in the electrophoretic ink layer. Display sheet.
(8) The electrophoretic display sheet according to any one of (5) to (7) above, wherein a gap smaller than at least one of the particle diameters is formed in the partition wall of the insulating material. .
(9) The electrophoretic display sheet according to any one of the above (5) to (8), wherein an adhesive layer or an adhesive layer is further formed on the outer surface of the sealing layer of the electrophoretic display sheet.
(10) A cellular structure composed of partition walls made of an insulating material is formed on a light transmissive electrode surface formed on a light transmissive substrate material, and electrophoretic ink is filled into the cellular structure. An electrophoretic display sheet, wherein the electrophoretic ink layer is sealed by bonding the sealing film on which the adhesive layer is formed to the electrophoretic ink layer and then curing the adhesive layer. .
(11) The electric barrier according to (10), wherein the partition wall of the insulating material has a width of a short axis of the partition wall becoming narrower from the light-transmitting electrode surface side toward the sealing film side. Electrophoresis display sheet.
(12) The electrophoresis according to (11) above, wherein the width of the short axis of the partition wall on the sealing layer side is smaller than the particle diameter of at least one of the electrophoretic particles contained in the electrophoretic ink layer. Display sheet.
(13) The electrophoretic display sheet according to any one of (10) to (12) above, wherein a gap smaller than at least one of the particle diameters is formed in the partition wall of the insulating material. .
(14) The electrophoretic display sheet as described in any one of (10) to (13) above, wherein an adhesive layer or an adhesive layer is formed on the outer surface of the sealing layer of the electrophoretic display sheet.
(15) Formed by peeling and bonding the film of the electrophoretic display sheet according to any one of (1) to (4) above on a substrate on which one or more electrodes are formed. An electrophoretic display medium characterized by the above.
(16) Electrophoresis characterized in that the electrophoretic display sheet according to (9) or (14) is bonded via an adhesive layer or an adhesive layer on a substrate on which one or more electrodes are formed. Display medium.

According to the present invention, a high-quality electrophoretic display sheet having excellent durability, display characteristics, and productivity at low cost and an electrophoretic display medium using the same are provided.

(A) is a schematic longitudinal cross-sectional view of the electrophoretic display sheet which shows 1st Embodiment used as an example of this invention, (b) is an expanded schematic longitudinal cross-sectional view of (a). (A)-(c) is a schematic drawing explaining the manufacturing process of the electrophoretic display sheet of 1st Embodiment for every process. (A) is explanatory drawing in case the width | variety of the short axis of a partition is narrowing toward the sealing adhesive layer (or sealing adhesion layer) side, (b) is the width | variety of the short axis of a partition wall sealingly bonded. It is explanatory drawing in the case where it does not become narrow toward the layer (or sealing adhesion layer) side. (A)-(d) is explanatory drawing which shows the other example of each shape (vertical cross-sectional shape) of the short axis of a partition. (A) to (c) are a partial plan view, a partial front view, and a partial perspective view showing an example of a cellular structure (cross-girder type) constituted by partition walls. (A) to (c) are a partial plan view, a partial front view, and a partial perspective view showing another example (hexagonal shape type) of a cellular structure constituted by partition walls. It is explanatory drawing explaining the state of the electrophoretic ink layer using the cellular structure (hexagon shape type | mold) comprised by the partition. (A) And (b) is explanatory drawing explaining the state which formed the communicating hole in each cell of the cellular structure (hexagon shape type, cross-girder type) comprised by the partition. (A) is a schematic longitudinal sectional view showing a state in which the release film of the electrophoretic display sheet is peeled off, and (b) is a state in which the release film is peeled off from the electrophoretic display sheet in the backplane (TFT, segment substrate, etc.) It is explanatory drawing which shows the state which bonds. (A) is a schematic longitudinal cross-sectional view of the electrophoretic display sheet which shows an example of 2nd Embodiment of this invention, (b) is an expanded schematic longitudinal cross-sectional view of (a). (A)-(d) is a schematic drawing explaining the manufacturing process of the electrophoretic display sheet of 2nd Embodiment of this invention for every process. (A) is a schematic longitudinal cross-sectional view which shows the state which peels the peeling film of the electrophoretic display sheet of 2nd Embodiment of this invention, (b) is the state which peeled the peeling film from the electrophoretic display sheet, and back It is explanatory drawing which shows the state which bonds a plane (TFT, a segment board | substrate, etc.). (A) is a schematic longitudinal cross-sectional view of the electrophoretic display sheet of 3rd Embodiment of this invention, (b) is an expansion schematic longitudinal cross-sectional view of (a). (A)-(c) is a schematic drawing explaining the manufacturing process of the electrophoretic display sheet of 3rd Embodiment of this invention for every process. It is explanatory drawing which shows the state which bonds a back plane (TFT, segment substrate, etc.) through the contact bonding layer or adhesion layer formed in the outer surface of the electrophoretic display sheet of 3rd Embodiment of this invention.

Embodiments of the present invention will be described below in detail with reference to the drawings. In each figure, the same numerals indicate the same or equivalent components.
In the present invention, the electrophoretic display sheet of each embodiment forms a cellular structure composed of partition walls of an insulating material on a light transmissive electrode surface formed on a light transmissive substrate material, Each cell structure is filled with an electrophoretic ink, and a film having a specific structure according to any one of the first to third embodiments, which will be described in detail below, is bonded to the electrophoretic ink layer. The electrophoretic display sheet of the embodiment is configured, and the electrophoretic display medium is formed by peeling the film of the electrophoretic display sheet of each embodiment on a substrate on which one or more electrodes are formed. It is formed by pasting.

(First embodiment, FIGS. 1 to 9)
FIGS. 1 to 9 are explanatory views of a first embodiment as an example of the present invention. FIG. 1 is a schematic longitudinal sectional view and an enlarged schematic longitudinal sectional view of an electrophoretic display sheet. FIG. It is the schematic explaining the manufacturing process of the electrophoretic display sheet of one Embodiment for every process.
As shown in FIGS. 1 and 2, the electrophoretic display sheet A according to the first embodiment includes a light transmissive electrode surface 11 formed on a light transmissive substrate material 10 and the light transmissive electrode. A cellular structure 20 constituted by partition walls 15, 15... Of an insulating material on the surface 11, an electrophoretic ink (layer) 25 filled in the cellular structure 20, and a sealing adhesive layer (or sealing). And a film 35 on which an adhesive layer 30 is formed.

The light transmissive substrate material 10 may be any material as long as it has light transmissive properties, such as transparent inorganic materials such as glass, quartz, sapphire, MgO, LiF, and CaF ₂ , fluororesin, polyester, polycarbonate, polyethylene, Examples thereof include resin films or ceramics of organic polymers such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN).
Preferably, it is desirable to use a flexible resin film for roll-to-roll production and large area.

The light transmissive electrode surface (electrode layer) 11 is made of, for example, a transparent conductive material such as ITO, ZnO, SnO ₂ , aluminum (Al), gold (Au), platinum (Pt), copper (Cu), silver It can be formed using a metal such as (Ag), nickel (Ni), or 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.

On the light transmissive electrode surface 11, as shown in FIG. 1 and FIG. 2A, a cellular structure 20 composed of partition walls 15, 15. For example, a cellular structure 20 is formed by laser processing an insulating resin material such as a PET film having a certain thickness to form a square, hexagon, circle, or the like and bonding it onto the electrode surface 11. can do. Moreover, after forming a photocurable insulating layer on the electrode surface 11, the cellular structure 20 can be formed by patterning the insulating layer using a photolithography method. In addition, it is also possible to form a cellular structure 20 by a method such as hot embossing by forming a thermoplastic insulating resin material on the electrode surface 11. In addition, the partition 15 may be called a spacer, a pillar, a wall, a rib, etc. from the shape and the objective.

In the present invention, the shape of the partition wall 15 made of an insulating material is such that the width of the short axis of the partition wall 15 decreases from the light-transmitting electrode surface 11 side toward the sealing adhesive layer (or sealing adhesive layer) 30 side. In this embodiment, the longitudinal section has a triangular shape (isosceles triangular shape).
More preferably, the width of the minor axis (top) of the partition wall 15 on the sealing adhesive layer (or sealing adhesive layer) 30 side is larger than the particle diameter of at least one of the electrophoretic particles contained in the electrophoretic ink 25 described later. Small is desirable. Specifically, as shown in FIG. 3A, the top 15a side is narrowed so that the electrophoretic particles do not remain on the top 15a of the partition wall 15 when the electrophoretic ink is filled. When the electrophoretic ink is filled, as shown in FIG. 3B, when the electrophoretic particles have a width that remains on the top portion 15b of the partition wall 15, the sealing adhesive layer (or sealing adhesive layer) 30 and The removal of the electrophoretic particles (cleaning) is necessary because it hinders adhesion, but as shown in FIG. 3A, the width of the short axis (top) 15a of the partition wall 15 is at least that of the electrophoretic particles used. Removal of the electrophoretic particles (cleaning) can be omitted by making the particle diameter smaller than one particle diameter, particularly preferably smaller than the minimum particle diameter of the electrophoretic particles, and the top portion 15a is sealed. Since it will bite into the adhesive layer (or sealing adhesive layer) 30, it is possible to suppress deviation during production and to increase the contact area, so that the sealing property is excellent. In FIG. 3, 26 and 27 indicate electrophoretic particles, 26 is black particles (carbon black-containing resin particles), and 27 is white particles (titanium oxide particles).

The vertical cross-sectional shape of the partition wall 15 made of this insulating material may be any shape as long as the width of the short axis of the partition wall 15 becomes narrower toward the sealing adhesive layer (or sealing adhesive layer) 30. Examples of the vertical cross-sectional shapes shown in FIGS. 4 (a) to 4 (d) are given. Also in each of these shapes, the width of each top portion 15a of each partition wall 15 is smaller than the particle diameter of at least one of the electrophoretic particles to be used, and particularly preferably smaller than the minimum particle diameter of the electrophoretic particles. It is desirable.
The length X of the minor axis on the electrode surface 11 side of the partition wall 15 varies depending on the type of electrophoretic ink, the electrophoretic display medium, etc., as shown in FIG. In order to ensure a sufficient aperture ratio, it is preferable to set it to 20 μm or less. The height of the partition wall 15 is preferably slightly higher than the height Y of the electrophoretic ink layer 20 to be filled: 20 to 40 μm.

A cellular structure 20 in which a plurality of small chambers ( cells 16, 16...) Are formed by partition walls 15, 15... Standing on the light-transmitting electrode surface 11. These cells 16 are separated from each other by a partition wall 15 and can be provided in various shapes such as a circle, a rectangle (rectangle, square), and a hexagon.
FIG. 5 and FIG. 6 show an example and other examples of the cellular structure 20 constituted by the partition walls 15, 15... Of an insulating material having the above-described longitudinal cross section having a triangular shape (isosceles triangular shape). FIG. 5 shows a cellular structure 20 of a cross-beam type, and FIG. 6 shows a cellular structure 20 of a hexagonal shape.

The cellular structure 20 formed on the electrode surface 11 is filled with the electrophoretic ink 25 as shown in FIG. As a method of filling the electrophoretic ink 25, for example, coating with a die coater or the like, and the electrophoretic ink 25 disposed at an arbitrary position of the electrode substrate are spread by substantially contacting with a bar coater, a doctor blade, a comma roll, or the like. Any method can be used as long as it is a method that can fill the cells with ink, such as a printing method using screen printing or the like, or filling with an ink jet or a dispenser.

The electrophoretic ink 25 to be used is not particularly limited, and any electrophoretic ink that includes at least one type of electrophoretic particles and a solvent such as a solvent may be used.
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 an example of the electrophoretic ink 25 that can be used, it can be formed of 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 size of 0.05 to 20 μm, and particularly preferably an average particle size of 0.1 to 10 μm. The total content of these fine particles is preferably 5 to 95% by mass, more preferably 10 to 80% by mass, based on 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 20 to 80%, more preferably 35%, based on the total amount of electrophoretic ink. It is desirable to set it to ~ 65%.

The electrophoretic ink 25 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 in an amount of 0.5 to 30%.
As the charge control agent, various types conventionally used for electrophoresis inks can be used.

When the electrophoretic ink 25 is filled, preferably, a wettability adjusting step for improving the wettability of the electrophoretic ink 25 may be added to the surface of the substrate 10. The electrophoretic ink 25 is sufficiently distributed to the inner walls and corners of the plurality of cells 16, 16... Composed of the insulating partition walls 15, and a gas such as air is supplied to the cells 16 composed of the insulation partition walls 15, 15. , 16... Is a preferred process for expelling from within.
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 filling the electrophoretic ink 25, it is dissolved in the electrophoretic ink 25 before filling, at the time of filling, or after filling so that bubbles such as air do not enter or remain 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. This facilitates the replacement of the voids in the electrophoretic ink 25 and the air in the cells with the electrophoretic ink 25, thereby reducing the possibility of bubbles remaining in the panel. After the film 35 on which the adhesive layer (or sealing pressure-sensitive adhesive layer) 30 is formed is bonded (after sealing), air bubbles are prevented from being mixed.

As a method of deaeration before filling, for example, a method of stirring the electrophoretic ink 25 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.

In this 1st Embodiment, since the upper surface of the partition 15, 15 ... is bonded by the film 35 in which the sealing adhesive layer (or sealing adhesion layer) 30 mentioned later was formed, the said deaeration process is performed. However, the internal pressure changes due to the bonding load and temperature change at the time of bonding, and each cell 16 from which the cellular structure 20 is separated becomes a reduced pressure state. As shown in FIG. .. (Saturated state) 17, 17. Therefore, as shown in FIGS. 8A and 8B, at least one particle diameter contained in the electrophoretic ink 25, particularly preferably electric, is formed at a portion where the partition walls 15, 15. It is desirable to form communication holes 18, 18... Having gaps smaller than the minimum particle diameter of the migrating particles. Electrophoretic particles cannot pass through, but by forming communication holes 18, 18... With gaps that allow the solvent to pass through, local pressure changes inside each cell 16 are dispersed and evenly distributed by the movement of the solvent. It is alleviated, bubbles are less likely to be generated, and display characteristics can be improved. In addition, when the gap is smaller than one particle diameter but larger than the other particle diameter, one large particle closes the gap, so that the movement of small particles that affect display is not caused. Is. The communication hole made up of the small gap is preferably formed in a portion where the partition walls 15, 15... Of the insulating material intersect, but similarly, a communication hole made up of a small gap can be provided in addition to the crossed portion. is there.

FIG. 8A shows a cell-like structure (hexagonal shape) 20 constituted by the partition walls 15, 15... At the portions 18, 18. Are formed with communication holes 18, 18. FIG. 8 (b) shows the above characteristics for each unit of a portion where the partition walls 15, 15 of the insulating material intersect in the cellular structure (cross-beam type) 20 constituted by the partition walls 15, 15,. Are formed with communication holes 18, 18.

In the first embodiment, as shown in FIG. 2 (c), a sealing adhesive layer (or sealing adhesive) that is disposed opposite to the electrode surface 11 filled with the electrophoretic ink 25 and seals the electrophoretic ink 25. The target electrophoretic display sheet A can be obtained by bonding the film 35 on which the (layer) 30 is formed to the upper surface of each structure 15.
The sealing adhesive layer (or sealing adhesive layer) 30 can be sealed to the extent that electrophoretic ink does not leak from the cell, and can be bonded (or adhered) to the backplane described later. For example, a polymer or a polymer precursor material such as polyvinylidene fluoride, polyurethane, nitrocellulose, or cellulose acetate that becomes a high dielectric constant, low volume resistivity material is desirable. Further, using the above polymer as a base polymer, in order to further increase the dielectric constant, alkyl quaternary ammonium salts such as tetrabutylammonium hydrogen sulfate (TBAHS) and tetrabutylammonium hexafluorophosphate (TBAHP), fine particles of barium titanate, titanium It can also be configured by blending strontium acid or the like at a predetermined ratio. Further, various materials such as ultraviolet curable, thermoplastic, thermosetting, two-component curable, moisture curable, and catalyst curable can be used as the material.

Furthermore, after applying a polymer solution dissolved in a solvent to the film, it is also possible to remove the excess solvent before use.
Preferably, the above materials are suitably combined to form a sealing adhesive layer (or sealing adhesive layer) 30 having a volume resistivity of 10 ⁸ to 10 ¹⁴ Ωcm and a dielectric constant of 3 to 11.
The thickness of the sealing adhesive layer (or sealing adhesive layer) 30 varies depending on the volume specific resistance, dielectric constant and electrophoretic ink layer height of the electrophoretic ink to be used. In order to make it possible to apply an appropriate voltage and seal the electrophoretic ink, it is preferably 1 to 10 μm, more preferably 0.5 to 5 μm.

Moreover, the film 35 to be used is a film for peeling, and is a so-called release sheet, release film, which is obtained by coating a surface of PET, PE, paper or the like with a silicone release agent, a fluorine release agent, or the like. Release paper or the like can be used, and is determined as appropriate in combination with the sealing adhesive layer (or sealing adhesive layer) to be used.
As a method of forming a sealing adhesive layer (or sealing adhesive layer) on the film, for example, a liquid obtained by dissolving a polymer material in an organic solvent is applied using a coater, and then the excess solvent is removed to form. After a method, a polymer precursor material such as a monomer or an oligomer is applied on a film together with a catalyst, and then formed by polymerizing using heat or light, a photocurable material is applied on the film, A method of forming a semi-cured state by irradiation with light (not a state of complete curing but a tacky or viscous state) can be raised, but is not limited thereto. Further, two or more kinds of materials such as a combination of a thermoplastic material and a photocurable material, or a combination of a thermosetting material and a photocurable material can be mixed and used.
The sealing adhesive layer (or sealing adhesive layer) 30 has a function of sealing the electrophoretic ink inside the cell in contact with the partition wall, and it melts into the electrophoretic ink or sinks away from the film. In addition to having a viscosity, hardness, etc., there is also a function of bonding with a backplane described later. Therefore, the thickness, viscosity, tackiness, hardness, etc. of the sealing adhesive layer (or sealing adhesive layer) are appropriately adjusted so as to have the above function.

Each of the films 35 having the sealing adhesive layer (or sealing adhesive layer) 30 having the above-described properties that is disposed opposite to the substrate 10 on which the electrode 11 filled with the electrophoresis ink 25 is formed and that seals the electrophoresis ink 25 is provided. As a method of bonding to the upper surface of the partition wall 15, for example, after sealing one end of the film 35 having the sealing adhesive layer (or sealing adhesive layer) 30, the sealing adhesive layer is passed by passing between rollers disposed opposite to each other. The electrophoretic display medium sheet A shown in FIG. 1 can be obtained by bonding (or sealing adhesive layer) 30 to the upper surface of each partition wall 15.
At this time, as an auxiliary of bonding, pressurization with a roller, heating, light irradiation, and the like can be performed together.
As described above, after making various adjustments, a sealing adhesive layer (or sealing adhesive layer) is formed on the film, and then bonded to the upper surface of each partition wall 15 so that the electrophoretic ink becomes a sealing adhesive material (or sealing). Even when the specific gravity is smaller than that of the adhesive material, the sealing adhesive material (or sealing adhesive material) can be sealed without sinking from the surface.

In the first embodiment, the electrophoretic display medium is obtained by peeling off the film 35 of the obtained electrophoretic display sheet A and bonding an electrode substrate (backplane) on which one or more electrodes are formed. An electrophoretic display device can be obtained by providing a control unit and the like.
Examples of the substrate on which one or more electrodes are formed include various electrode substrates conventionally used in electronic paper and electrophoretic display devices, such as a TFT substrate, a segment substrate, and a solid substrate.
FIG. 9 shows, after peeling the release film 35 of the obtained electrophoretic display medium sheet A (see FIG. 9A), for example, a TFT substrate 60 serving as a backplane is attached to a sealing adhesive layer (or sealing adhesive layer). ) 30 and the electrophoretic display medium can be manufactured.
At this time, as an auxiliary of bonding, pressurization with a roller, heating, light irradiation, and the like can be performed together.
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.

(Second Embodiment, FIGS. 10 to 12)
10 to 12 are explanatory diagrams for explaining the second embodiment of the present invention.
In the electrophoretic display sheet of the second embodiment, a sealing precursor layer 40 is formed instead of the film 35 on which the sealing adhesive layer (or sealing adhesive layer) 30 used in the first embodiment is formed. After the film 45 is bonded to the electrophoretic ink layer 25, the sealing precursor layer 40 is cured to form a sealing layer 41, and the electrophoretic ink layer 25 is sealed. It differs only in that it is configured by peeling from the sealing layer 41, and each configuration of the substrate material 10, the electrode surface 11, the partition wall 15, the cellular structure 20, and the electrophoretic ink (layer) 25, and FIG. 3 to 8 and the description thereof (a configuration in which the width of the short axis of the partition wall 25 is narrowed, the width of the short axis of the partition wall is smaller than the particle diameter of at least one of the electrophoretic particles, A gap smaller than the particle size of Since the fact that) etc. are the same as the electrophoretic display sheet of the first embodiment, description thereof will be omitted. 10 to 12, the same contents as those in the first embodiment are denoted by the same reference numerals in each drawing, and the description thereof is omitted.
As shown in FIGS. 10 and 11, the electrophoretic display sheet B according to the second embodiment includes a light transmissive electrode surface 11 formed on a light transmissive substrate material 10, and the light transmissive electrode. A cellular structure 20 constituted by partition walls 15, 15... Of an insulating material on the surface 11, an electrophoretic ink (layer) 25 filled in the cellular structure 20, and a sealing precursor layer 40. And a formed film 45.

In the second embodiment, as shown in FIG. 11C, a sealing precursor that is a precursor material that is disposed so as to face the electrode surface 11 filled with the electrophoretic ink 25 and seals the electrophoretic ink 25. After the film 45 on which the layer 40 is formed is bonded to the upper surface of each structure 15, the sealing precursor layer 40 is cured to form the sealing layer 41 and seal the electrophoretic ink layer 20. As shown in FIG. 11 (d), the target electrophoretic display sheet B can be obtained by peeling the film 45 from the sealing layer 41.
As the sealing precursor layer 40, the sealing layer 41 is formed by curing, and is particularly limited as long as the electrophoretic ink can be sealed by curing to the extent that the electrophoretic ink does not leak from the cell. Not, for example, UV curable resins such as epoxy acrylate, urethane acrylate, urethane, thermosetting resins such as phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, polyurethane resin, two-component urethane, etc. Various materials such as a two-component curable resin, a moisture curable resin such as a moisture curable urethane resin, and a catalyst curable resin such as epoxy and isocyanate can be used.

Furthermore, after applying the material solution of the sealing precursor dissolved in the solvent to the film, it is possible to remove the excess solvent and use it.
In addition, by adding a predetermined proportion of alkyl quaternary ammonium salts such as tetrabutylammonium hydrogen sulfate (TBAHS) and tetrabutylammonium hexafluorophosphate (TBAHP), fine particle barium titanate, strontium titanate and the like, It can also be configured by adjusting the volume resistivity.
Preferably, the above-described materials are suitably combined to form a sealing precursor layer 40 having a volume resistivity of 10 ⁸ to 10 ¹⁴ Ωcm and a dielectric constant of 3 to 11.
The thickness of the sealing precursor layer 40 varies depending on the volume resistivity, the dielectric constant value, and the height of the electrophoretic ink layer to be used, but a sufficient voltage can be applied to the electrophoretic ink. In order to seal the electrophoretic ink, it is preferably 1 to 10 μm, more preferably 0.5 to 5 μm.

The film 45 to be used is a peeling film similar to that in the first embodiment, and the surface of PET, PE, paper or the like is coated with a silicone release agent, a fluorine release agent, or the like. A release sheet, a release film, a release paper, or the like can be used, and is appropriately determined in combination with the sealing adhesive layer (or sealing adhesive layer) to be used.
As a method of forming the sealing precursor layer 40 on the film, for example, a method in which a liquid obtained by dissolving a polymer material in an organic solvent is applied using a coater, and then the excess solvent is removed, a monomer, A method of forming a polymer precursor material such as an oligomer by applying it on a film together with a catalyst, or after applying a photocurable material on a film and then irradiating it with a light to a semi-cured state (in the case of irradiation that is completely cured) However, the present invention is not limited to these methods. Further, two or more kinds of materials such as a combination of a thermoplastic material and a photocurable material, or a combination of a thermosetting material and a photocurable material can be mixed and used.
The sealing precursor layer 40 has such a viscosity and hardness that it does not dissolve or sink in the electrophoretic ink away from the film, and after curing, the electrophoretic ink is brought into contact with the partition wall and the cell is passed through the cell. It has a function of sealing inside. Therefore, the thickness, viscosity, tackiness, hardness, etc. of the sealing precursor layer are appropriately adjusted so as to have the above function.

A film 45 having a sealing precursor layer 40 of the above-described characteristics that is disposed so as to seal the electrophoretic ink 25 is bonded to the upper surface of each partition wall 15 on the substrate 10 on which the electrode 11 filled with the electrophoretic ink 25 is formed. As a method, for example, after one end of the film 45 having the sealing precursor layer 40 is combined, the sealing precursor layer 40 is pasted to the upper surface of each partition wall 15 by passing between rollers disposed opposite to each other. After forming the sealing layer 41 that seals the electrophoretic ink layer 25 by curing the sealing precursor layer 40, the film 45 is peeled off as shown in FIG. An electrophoretic display medium sheet B can be obtained.
At this time, as an auxiliary of bonding, pressurization with a roller, heating, light irradiation, and the like can be performed together.
As described above, after forming the sealing precursor layer 40 on the film after making various adjustments, the electrophoretic ink has a specific gravity smaller than that of the sealing precursor material by bonding to the upper surface of each partition wall 15. Even if it exists, it becomes possible to seal, without sealing precursor material sinking from the surface.

In the second embodiment, an adhesive layer (or adhesive layer) 46 is formed on the outer surface of the sealing layer 32 of the obtained electrophoretic display sheet B as shown in FIG. An electrophoretic display medium can be produced by bonding an electrode substrate (back plane) on which the above electrodes are formed, and an electrophoretic display device can be obtained by providing a control unit or the like.
Since the adhesive layer (or adhesive layer) 46 is the same as that of the first embodiment, the description thereof is omitted.
After the release film 45 of the obtained electrophoretic display medium sheet B is peeled off as shown in FIG. 12A, an adhesive layer (or adhesive layer) 46 is formed on the outer surface of the sealing layer 41. As in the first embodiment, an electrophoretic display medium can be manufactured by bonding a TFT substrate 60 serving as a backplane to an adhesive layer (or adhesive layer) 46.
At this time, as an auxiliary of bonding, pressurization with a roller, heating, light irradiation, and the like can be performed together. Note that the use (use application, rewriting method, etc.) of the electrophoretic display medium is the same as in the first embodiment, and the description thereof is omitted.

In the electrophoretic display sheet B according to the second embodiment of the present invention configured as described above, a high-quality electrophoretic display sheet excellent in durability, display characteristics, and productivity at low cost, and an electrophoretic display using the same A medium will be provided. In the second embodiment, in particular, an electrophoretic display sheet B having a large area with excellent durability and display characteristics can be mass-produced roll-to-roll, and can be produced without matching the size of the backplane. It becomes possible to cut and use it easily if necessary.
In addition, the electrophoretic display device obtained from the electrophoretic display sheet B realizes high contrast display, and can display contrast with high reliability even during repeated display, and has excellent responsiveness and display. Deterioration of characteristics is extremely small.

(Third embodiment, FIGS. 13 to 15)
13 to 15 are explanatory diagrams for explaining the third embodiment of the present invention.
The electrophoretic display sheet of the third embodiment includes a film 35 on which the sealing adhesive layer (or sealing adhesive layer) 30 used in the first embodiment is formed, and the sealing used in the second embodiment. Instead of the film 45 having the stop precursor layer 40, the sealing film 55 on which the adhesive layer 50 is formed is bonded to the electrophoretic ink layer 25, and then the electrophoretic ink layer 25 is cured by curing the adhesive layer 50. The only difference is that the substrate material 10, the electrode surface 11, the partition wall 15, the cellular structure 20, the electrophoretic ink (layer) 25, and FIGS. 3 to 8 and Description thereof (configuration in which the width of the minor axis of the partition wall 25 is narrowed, the width of the minor axis of the partition wall is smaller than the particle diameter of at least one of the electrophoretic particles, A small gap is formed Since the) etc. are the same as the electrophoretic display sheet of the first embodiment, description thereof will be omitted. In FIGS. 13 to 15, the same contents as those in the first embodiment are denoted by the same reference numerals in each drawing, and the description thereof is omitted.
As shown in FIGS. 13 and 14, the electrophoretic display sheet C according to the third embodiment of the present invention includes a light-transmitting electrode surface 11 formed on a light-transmitting substrate material 10, and the light-transmitting surface. A cell-like structure 20 composed of partition walls 15, 15... Of the insulating material, an electrophoretic ink (layer) 25 filled in the cell-like structure 20, and an adhesive layer 50 are formed on the electrode surface 11. The sealing film 55 is made.

In the third embodiment, as shown in FIG. 14C, a sealing film in which an adhesive layer 50 that is disposed so as to be opposed to and seals the electrophoretic ink 25 is formed on the electrode surface 11 filled with the electrophoretic ink 25. After bonding 55 to the upper surface of each structure 15, the electrophoretic ink layer 25 is sealed by curing the adhesive layer 50, and the target electrophoretic display sheet C can be obtained.
The adhesive layer 50 is not particularly limited as long as it can bond the partition wall 15 and the sealing film 55 and can be bonded to the sealing film by curing to such an extent that the electrophoretic ink does not leak from the cell. However, polymers or polymer precursor materials such as polyurethane, nitrocellulose, cellulose acetate and the like are desirable. Further, with the above polymer as a base polymer, alkyl quaternary ammonium salts such as tetrabutylammonium hydrogen sulfate (TBAHS) and tetrabutylammonium hexafluorophosphate (TBAHP), fine particles of barium titanate, strontium titanate, etc. It can also comprise by mix | blending in a ratio. Furthermore, as the material, various materials such as ultraviolet curable, thermoplastic, thermosetting, two-component curable, moisture curable, and catalyst curable can be used.

Furthermore, after applying the polymer solution dissolved in the solvent to the sealing film 55, it is also possible to remove the excess solvent and use it.
Preferably, the above-mentioned materials are suitably combined to form the adhesive layer 50 having a volume resistivity of 10 ⁸ to 10 ¹⁴ Ωcm and a dielectric constant of 3 to 11.
The thickness of the adhesive layer 50 varies depending on the volume resistivity of the electrophoretic ink to be used, the value of the dielectric constant, the height of the electrophoretic ink layer, and the thickness of the sealing film. In order to seal the electrophoretic ink by adhering the partition wall 15 and the sealing film 55, the thickness is preferably 1 to 10 μm, more preferably 1 to 5 μm.

Although it does not specifically limit as the sealing film 55 to be used, It is desirable to use the film material which consists of a high dielectric constant material and a low volume specific resistance material. For example, polymer films, such as a polyvinylidene chloride film, a polyvinylidene fluoride film, a polyurethane film, a nitrocellulose film, a cellulose acetate film, can be mentioned.
Preferably, a polyvinylidene fluoride simple substance film, a copolymer film having a vinylidene fluoride content ratio of 50% by mass or more, a polyurethane film, and the like are desirable.

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 Soda, sodium tripolyphosphate, disodium ethylenediaminetetraacetate (EDTA-2Na), tetrabutylammonium hydrogen sulfate (TBAHS), tetrabutylammonium hexafluorophosphate (TBAHP), etc. Thermal stabilization aids such as rutile quaternary ammonium salts, fine particles of barium titanate and strontium titanate, magnesium oxide, etc .; various light stabilizers; various lubricants; various colorants, flame retardants, UV absorbers, etc. Can be mentioned. Some of these additives may be added simultaneously with or during the polymerization of the vinylidene chloride copolymer.
Preferably, each of the above materials is contained in the film in an amount of 1 to 30% by mass.

The thickness of the sealing film 55 varies depending on the volume resistivity, dielectric constant, electrophoretic ink layer height, and adhesive layer thickness of the electrophoretic ink to be used. Is preferably 1 to 20 μm, and more preferably 5 to 10 μm in order to seal the electrophoretic ink.
The sealing film 55 preferably has a volume resistivity of 10 ⁸ to 10 ¹⁴ Ωcm and a dielectric constant of 3 to 11.

As a method for forming the adhesive layer 50 on the sealing film, for example, a method in which a solution obtained by dissolving a polymer material in an organic solvent is applied using a coater, and then an excess solvent is removed, or a monomer or oligomer is formed. After the polymer precursor material is applied onto the sealing film together with the catalyst, the photocuring material is applied onto the film, and then irradiated with light to be in a semi-cured state (irradiation that can be completely cured). However, the present invention is not limited to these methods. Further, two or more kinds of materials such as a combination of a thermoplastic material and a photocurable material, or a combination of a thermosetting material and a photocurable material can be mixed and used.
The adhesive layer 50 has a function of adhering the partition wall and the sealing film to seal the electrophoretic ink inside the cell, and does not dissolve or sink in the electrophoretic ink apart from the sealing film. It has properties. Therefore, the thickness, viscosity, tackiness, hardness, etc. of the adhesive layer are appropriately adjusted so as to have the above functions.

A method of bonding a sealing film 55 having an adhesive layer 50 disposed opposite to the substrate 10 on which the electrode 11 filled with the electrophoretic ink 25 is formed and facing the electrophoretic ink 25 to the upper surface of each partition wall 15. As one example, after one end of the sealing film 55 having the adhesive layer 50 is aligned, the adhesive layer 50 is bonded to the upper surface of each partition wall 15 by passing between rollers disposed opposite to each other, and then the adhesive layer 50 The electrophoretic display medium sheet C shown in FIG. 15 formed by sealing the electrophoretic ink layer 25 can be obtained.
At this time, as an auxiliary of bonding, pressurization with a roller, heating, light irradiation, and the like can be performed together.
As described above, after the adhesive layer 50 is formed on the sealing film 55 after various adjustments, the electrophoretic ink has a specific gravity smaller than that of the adhesive layer material by bonding to the upper surface of each partition wall 15. In addition, the sealing adhesive layer material can be sealed without sinking from the surface.

In the third embodiment, an adhesive layer (or adhesive layer) 56 is formed on the outer surface of the sealing film layer 55 of the obtained electrophoretic display sheet C as shown in FIG. An electrophoretic display medium can be produced by bonding an electrode substrate (backplane) on which electrodes are formed, and an electrophoretic display device can be obtained by providing a control unit or the like.
The adhesive layer (or adhesive layer) 56 is not particularly limited as long as it is a material that can be adhered (or adhered) to the backplane, for example. For example, a high dielectric constant, low volume resistivity material and Polymeric or polymeric precursor materials such as polyvinylidene fluoride, polyurethane, nitrocellulose, cellulose acetate are desirable. Further, using the above polymer as a base polymer, in order to further increase the dielectric constant, alkyl quaternary ammonium salts such as tetrabutylammonium hydrogen sulfate (TBAHS) and tetrabutylammonium hexafluorophosphate (TBAHP), fine particles of barium titanate, titanium It can also be configured by blending strontium acid or the like at a predetermined ratio. Furthermore, the material can be constituted by blending various materials such as ultraviolet curable, thermoplastic, thermosetting, two-component curable, moisture curable, and catalyst curable at a predetermined ratio. Further, the thickness of the adhesive layer (or adhesive layer) 56 is preferably 1 to 10 μm, more preferably 1 to 5 μm.
As the substrate on which one or more electrodes are formed, as in the first embodiment, for example, a TFT substrate, a segment substrate, a solid substrate, etc., various electrode substrates conventionally used in electronic paper and electrophoretic display devices Can be mentioned.
FIG. 15 shows an example in which an adhesive (or adhesive layer) 56 is formed on the outer surface of the sealing film 55 of the obtained electrophoretic display medium sheet C, and then, for example, the TFT substrate 60 serving as a backplane is attached to the adhesive layer (or adhesive layer). The electrophoretic display medium can be manufactured by being attached to 56. At this time, as an auxiliary of bonding, pressurization with a roller, heating, light irradiation, and the like can be performed together. Note that the use (use application, rewriting method, etc.) of the electrophoretic display medium is the same as in the first embodiment, and the description thereof is omitted.

In the electrophoretic display sheet C according to the third embodiment of the present invention configured as described above, a high-quality electrophoretic display sheet having excellent durability, display characteristics, and productivity at low cost, and an electrophoretic display using the same A medium will be provided. In the third embodiment, a large area electrophoretic display sheet having excellent durability and display characteristics can be produced in a roll-to-roll manner, and can be produced without matching the size of the backplane. It can be cut and used easily according to the conditions.
In addition, the electrophoretic display device obtained from this electrophoretic display sheet can realize high contrast display, and can display contrast with high reliability even during repeated display, excellent response, and display characteristics. Deterioration of the product becomes extremely small.

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.

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

[Examples 1 to 4, according to the first embodiment, FIGS. 1 to 10]
(Example 1)
Through the following steps, an electrophoretic display sheet and an electrophoretic display medium were obtained.
1) Step of forming a plurality of cells composed of insulating partition walls on an electrode substrate A 125 μm-thick PET sheet (10 μm) formed with an ITO film, which is a transparent material, having a surface resistance of about 300Ω / □ as an electrode substrate × 10 cm) was used.
An acrylic UV curable resin material is applied on the first electrode substrate so as to have a thickness of 40 μm, and then exposed to UV and developed to form a plurality of grid-like cells (insulating high-density cells). And a cell size of 300 × 300 μm) was formed. Vertical cross-sectional shape of partition walls: isosceles triangle shape, base = 20 μm, height = 40 μm, top width: 2 μm or less.

2) Step of filling the cell with electrophoretic ink Composition of electrophoretic ink used:
Normal dodecane 75% by mass, titanium oxide particles [volume average particle diameter when measured with Microtrack (manufactured by Nikkiso Co., Ltd.): 10% by mass, carbon black-containing acrylic particles (magnified image taken with an electron microscope (Average particle diameter when image analysis (converted into area circle) by Mountec Co., Ltd.): about 6 μm) 10% by mass, 3% by mass of hydroxyethylamine, 2% by mass of sorbitan trioleate.
The electrophoretic ink was filled into the cell using a coater.

3) The process of bonding the electrode substrate and the film having the sealing adhesive layer (or sealing adhesive layer) As the sealing adhesive layer (or sealing adhesive layer), UV curable urethane acrylate resin whose viscosity is adjusted with butyl acetate Was coated on a 125 μm thick polyethylene film (10 × 10 cm), and then butyl acetate was removed to form a thickness of 8 μm.
One end of a film having a sealing adhesive layer (or sealing adhesive layer) is combined with the electrode substrate filled with the electrophoretic ink, and then pasted together by passing between rollers placed opposite to each other, and electrophoretic display A sheet was obtained.

Bubbles were not mixed in the display area of the obtained electrophoretic display sheet, and the distance between the electrode and the film having the sealing adhesive layer (or sealing adhesive layer) was uniform.
Further, a backplane (0.7 mm glass substrate on which an ITO solid electrode was formed) was bonded to the obtained electrophoretic display sheet, and ultraviolet rays were irradiated from the backplane side to cure the ultraviolet curable urethane acrylate resin. . Thereafter, it was confirmed that high contrast monochrome display was possible by alternately applying +50 v and −50 v voltages between the two electrodes.
Furthermore, when the obtained electrophoretic display medium was evaluated for display performance after being allowed to stand for 1 month at 50 ° C. under dry conditions, an electrophoretic display in which the display characteristics did not change from the initial state and display performance was very difficult to deteriorate. A medium was obtained. In addition, no bubble was observed in the cell.

(Example 2)
In Example 1 described above, a gap of about 5 μm was formed at the intersection of the insulating partition walls.

(Example 3)
In Example 1 above, the composition of the electrophoretic ink used was 78% by mass of normal decane, and titanium oxide-containing polyethylene particles (when the image magnified by an electron microscope was image-analyzed (converted into area circles) with McView (manufactured by Mountec) (Average particle size: about 15 μm) 10% by mass, carbon black-containing acrylic particles (average particle size: about 15 μm when an image magnified with an electron microscope is image-analyzed (converted into area circles) with Mac View (manufactured by Mountec) The composition was 10% by mass and 2% by mass of sorbitan trioleate, and a gap of about 10 μm was formed at the intersection of the insulating partition walls.

(Example 4)
In Example 1 above, a thermoplastic polyurethane resin was used as the sealing adhesive layer (or sealing adhesive layer). Specifically, a thermoplastic polyurethane resin is applied on a polyethylene release film so as to have a thickness of 8 μm, and is heated when bonded with a roller, and also when bonded with a backplane. An electrophoretic sheet and an electrophoretic medium were prepared.

(Performance evaluation of electrophoretic display media of Examples 2 to 4)
No bubbles were mixed in the display area of each electrophoretic display sheet obtained in Examples 2 to 4, and the distance between the electrode and the film having the sealing adhesive layer (or sealing adhesive layer) was uniform. .
Further, an electrode substrate was bonded to each of the electrophoretic display sheets obtained in Examples 2 to 4 in the same manner as in Example 1 above, and the obtained electrophoretic display medium was left to stand at 50 ° C. for 1 month. When the display performance and the like were evaluated, an electrophoretic display medium in which the display characteristics did not change from the initial stage and display resistance was hardly deteriorated was obtained. In addition, no bubble was observed in the cell.

[Conforms to Examples 5-7, Second Embodiment, FIGS. 11-13, etc.]
(Example 5)
Through the following steps, an electrophoretic display sheet and an electrophoretic display medium were obtained.
1) Step of forming a plurality of cells composed of insulating partition walls on an electrode substrate A 125 μm-thick PET sheet (10 μm) formed with an ITO film, which is a transparent material, having a surface resistance of about 300Ω / □ as an electrode substrate × 10 cm) was used.
An acrylic UV curable resin material is applied on the first electrode substrate so as to have a thickness of 40 μm, and then exposed to UV and developed to form a plurality of grid-like cells (insulating high-density cells). And a cell size of 300 × 300 μm) was formed. Vertical cross-sectional shape of partition wall: isosceles triangle shape, base = 18 μm, height = 40 μm, top width: 5 μm or less

2) Step of filling electrophoretic ink into cell Composition of electrophoretic ink used: The electrophoretic ink having the same composition as in Example 1 was filled into the cell using a coater.
3) The process of bonding together the electrophoretic display sheet on which the backplane and the sealing layer are formed As the sealing precursor layer, a dispersion of an ultraviolet curable urethane oligomer whose viscosity is adjusted with purified water (including a photocuring initiator) Was coated on a 70 μm thick PET film (10 × 10 cm), and then the water was removed to form a thickness of 8 μm.
After aligning one end of the film having the sealing precursor layer to the electrode substrate filled with the electrophoretic ink, it is bonded by passing between rollers placed opposite to each other, and irradiated with ultraviolet rays from the PET film side. The ultraviolet curable urethane resin was cured to form a sealing layer, and the PET film was peeled off to obtain an electrophoretic display sheet.

Bubbles were not mixed in the display area of the obtained electrophoretic display sheet, and the distance between the electrode and the sealing layer was uniform.
Further, a urethane hot melt layer having a thickness of 5 μm is formed as an adhesive layer (or adhesive layer) on the outer surface of the sealing layer of the obtained electrophoretic display sheet, and a backplane (ITO) is formed on the adhesive layer (or adhesive layer). The 125 μm PET substrate on which the solid electrode was formed was heated to 80 ° C. and thermally laminated. Thereafter, it was confirmed that high contrast monochrome display was possible by alternately applying +50 V and −50 V voltages between the two electrodes.
Furthermore, when the obtained electrophoretic display medium was evaluated for display performance after being allowed to stand for 1 month at 50 ° C. under dry conditions, an electrophoretic display in which the display characteristics did not change from the initial state and display performance was very difficult to deteriorate. A medium was obtained. In addition, no bubble was observed in the cell.

(Example 6)
In Example 5 described above, a gap of about 5 μm was formed at the portion where the insulating partition walls intersect.

(Example 7)
In Example 5, the composition of the electrophoretic ink was changed in the same manner as in Example 3, and a gap of about 10 μm was formed at the portion where the insulating partition walls intersected.

No bubbles were mixed in the display areas of the electrophoretic display sheets obtained in Examples 6 and 7, and the distance between the electrode and the film having the sealing layer 31 was uniform.
Furthermore, the electrode substrate was bonded to each of the electrophoretic display sheets obtained in Examples 6 and 7 in the same manner as in Example 5 above, and the obtained electrophoretic display medium was allowed to stand for 1 month under 50 ° C. drying conditions. When the display performance and the like were evaluated, an electrophoretic display medium in which the display characteristics did not change from the initial stage and display resistance was hardly deteriorated was obtained. In addition, no bubble was observed in the cell.

[Examples 8 to 10, according to the third embodiment, FIGS. 13 to 15 and the like]
(Example 8)
Through the following steps, an electrophoretic display sheet and an electrophoretic display medium were obtained.
1) Step of forming a plurality of cells composed of insulating partition walls on an electrode substrate A 125 μm-thick PET sheet (10 μm) formed with an ITO film, which is a transparent material, having a surface resistance of about 300Ω / □ as an electrode substrate × 10 cm) was used.
An acrylic UV curable resin material is applied on the first electrode substrate so as to have a thickness of 40 μm, and then exposed to UV and developed to form a plurality of grid-like cells (insulating high-density cells). And a cell size of 300 × 300 μm) was formed. Vertical cross-sectional shape of partition wall: isosceles triangle shape, base = 18 μm, height = 40 μm, top width: 5 μm or less

2) Step of filling electrophoretic ink into cell Composition of electrophoretic ink used: The electrophoretic ink having the same composition as in Example 1 was filled into the cell using a coater.
3) The process of bonding the sealing film which has an adhesive layer As an adhesive layer, the ultraviolet curable urethane acrylate resin which adjusted the viscosity on the 10 micrometer-thick polyvinylidene fluoride film (10x10 cm) used as a sealing film After coating, it was formed to a thickness of 5 μm.
After aligning one end of the sealing film having an adhesive layer to the electrode substrate filled with the electrophoretic ink, it is bonded by passing between rollers placed opposite to each other, and irradiated with ultraviolet rays from the polyvinylidene fluoride film side. Then, the ultraviolet curable urethane acrylate resin was cured to obtain an electrophoretic display sheet.

Bubbles were not mixed in the display area of the obtained electrophoretic display sheet, and the distance between the electrode and the sealing film having the adhesive layer was uniform.
Further, a urethane hot melt layer having a thickness of 5 μm is formed as an adhesive layer (or adhesive layer) on the outer surface of the sealing film of the obtained electrophoretic display sheet, and a backplane (ITO) is formed on the adhesive layer (or adhesive layer). The 125 μm PET substrate on which the solid electrode was formed was heated to 80 ° C. and thermally laminated. Thereafter, it was confirmed that high contrast monochrome display was possible by alternately applying +50 V and −50 V voltages between the two electrodes.
Furthermore, when the obtained electrophoretic display medium was evaluated for display performance after being allowed to stand for 1 month at 50 ° C. under dry conditions, an electrophoretic display in which the display characteristics did not change from the initial state and display performance was very difficult to deteriorate. A medium was obtained. In addition, no bubble was observed in the cell.

Example 9
In the above Example 8, the composition of the electrophoretic ink was changed in the same manner as in Example 3, and a gap of about 10 μm was formed at the portion where the insulating partition walls intersect.

(Example 10)
In Example 8 above, a thermoplastic polyurethane resin was used as the adhesive layer. Specifically, an electrophoretic display sheet is produced by applying a thermoplastic polyurethane resin on a polyvinylidene fluoride film as a sealing film so as to have a thickness of 5 μm, and heating the laminated film with a roller. The configuration.

(Performance evaluation of electrophoretic display media of Examples 9 and 10)
No bubbles were mixed in the display areas of the electrophoretic display sheets obtained in Examples 9 to 10, and the gap between the sealing film having the electrode and the adhesive layer was uniform.
Furthermore, the electrode substrate was bonded to each of the electrophoretic display sheets obtained in Examples 9 and 10 in the same manner as in Example 8 above, and the obtained electrophoretic display medium was allowed to stand for 1 month under 50 ° C. drying conditions. When the display performance and the like were evaluated, an electrophoretic display medium in which the display characteristics did not change from the initial stage and display resistance was hardly deteriorated was obtained. In addition, no bubble was observed in the cell.

The electrophoretic display sheet of the present invention and the electrophoretic display medium using the same include electronic paper such as electronic books and electronic newspapers, billboards such as signboards, posters, and blackboards, electronic price tags, electronic shelf labels, electronic advertisements, and mobile devices. It can use suitably for uses, such as a display part.

A B C Electrophoretic display sheet 10 Substrate 11 Electrode layer 15 Partition 16 Cell 20 Cellular structure 25 Electrophoretic ink 30 Sealing adhesive layer (or sealing adhesive layer)
35 Film 40 Sealing precursor layer 41 Sealing layer 45 Film 46 Adhesive layer (or adhesive layer)
50 Adhesive layer 55 Sealing film 56 Adhesive layer (or adhesive layer)
60 Backplane (TFT substrate)

Claims (16)

1. A cell-like structure composed of partition walls made of an insulating material is formed on the light-transmitting electrode surface formed on the light-transmitting substrate material. The cell-like structure is filled with electrophoretic ink and sealed. An electrophoretic display sheet, wherein a film on which an adhesive layer or a sealing adhesive layer is formed is bonded to the electrophoretic ink layer.
2. 2. The electrical barrier according to claim 1, wherein the partition wall of the insulating material has a width of a short axis of the partition wall becoming narrower from the light transmissive electrode surface side toward the sealing adhesive layer or the sealing adhesive layer. Electrophoresis display sheet.
3. 3. The electricity according to claim 2, wherein the width of the minor axis of the partition wall on the side of the sealing adhesive layer or the sealing adhesive layer is smaller than the particle diameter of at least one of the electrophoretic particles contained in the electrophoretic ink layer. Electrophoresis display sheet.
4. 4. The electrophoretic display sheet according to claim 1, wherein a gap smaller than at least one of the particle diameters is formed in the partition wall made of the insulating material.
5. A cell-like structure composed of partition walls made of an insulating material is formed on the light-transmitting electrode surface formed on the light-transmitting substrate material. The cell-like structure is filled with electrophoretic ink and sealed. After the film on which the stop precursor layer is formed is bonded to the electrophoretic ink layer, the sealing precursor layer is cured to form a sealing layer and seal the electrophoretic ink layer. An electrophoretic display sheet, wherein a film is peeled from a sealing layer.
6. 6. The electrophoretic display sheet according to claim 5, wherein the partition wall of the insulating material has a width of a short axis of the partition wall narrowing from the light transmissive electrode surface side toward the sealing layer.
7. The electrophoretic display sheet according to claim 6, wherein the width of the minor axis of the partition wall on the sealing adhesion layer side is smaller than the particle diameter of at least one of the electrophoretic particles contained in the electrophoretic ink layer.
8. The electrophoretic display sheet according to any one of claims 5 to 7, wherein a gap smaller than at least one of the particle diameters is formed in the partition wall of the insulating material.
9. The electrophoretic display sheet according to any one of claims 5 to 8, further comprising an adhesive layer or an adhesive layer formed on the outer surface of the sealing layer of the electrophoretic display sheet.
10. A cell-like structure composed of partition walls made of an insulating material is formed on a light-transmitting electrode surface formed on a light-transmitting substrate material, and electrophoretic ink is filled into the cell-like structure and bonded. An electrophoretic display sheet, wherein the electrophoretic ink layer is sealed by bonding the sealing film on which the layer is formed to the electrophoretic ink layer and then curing the adhesive layer.
11. 11. The electrophoretic display sheet according to claim 10, wherein the partition wall of the insulating material has a width of a short axis of the partition wall narrowing from the light transmissive electrode surface side toward the sealing film side.
12. The electrophoretic display sheet according to claim 11, wherein the width of the minor axis of the partition wall on the sealing adhesion layer side is smaller than the particle diameter of at least one of the electrophoretic particles contained in the electrophoretic ink layer.
13. 13. The electrophoretic display sheet according to claim 10, wherein a gap smaller than at least one of the particle diameters is formed in the partition wall of the insulating material.
14. 14. The electrophoretic display sheet according to claim 10, further comprising an adhesive layer or an adhesive layer formed on the outer surface of the sealing layer of the electrophoretic display sheet.
15. Electrophoresis characterized by being formed by peeling and bonding the film of an electrophoretic display sheet according to any one of claims 1 to 4 on a substrate on which one or more electrodes are formed. Display medium.
16. 15. An electrophoretic display medium, wherein the electrophoretic display sheet according to claim 9 or 14 is bonded via an adhesive layer or an adhesive layer on a substrate on which one or more electrodes are formed.

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