JP2016075877A - Electrophoretic display medium sheet and electrophoretic display medium using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophoretic display medium sheet that eliminates necessity of an adhesion layer for electrical connection with an electrode plane, and an electrophoretic display medium using the same.SOLUTION: An electrophoretic display medium sheet A comprises: a substrate 10 with light permeability; an electrophoretic ink 20; an ink encapsulation film 30 arranged facing the substrate 10 and encapsulating the electrophoretic ink 20; and structures 15, 15 ... formed between the substrate 10 and the ink encapsulation film 30. The ink encapsulation film 30 includes a thermoplastic resin film which is composed of at least composed a thermoplastic resin composition containing a thermoplastic resin and a polymer type antistatic agent, and in which an ohmic value of the ink encapsulation film reaches 10 times or less the ohmic value of the electrophoretic ink.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sheet for an electrophoretic display medium that can reversibly change its visual state by the action of an electric field or the like, and an electrophoretic display medium using the same, and more particularly to electrical connection with an electrode surface. The present invention relates to an electrophoretic display medium sheet that does not require an adhesive layer 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.

  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.

For example, 1) a process for producing an encapsulated electrophoretic display, which is dispersed in a suspension fluid. Providing an electrophoretic medium with a plurality of separate droplets, each containing a plurality of charged particles that can move in the suspending fluid when an electric field is applied, in a polymer binder, and a backplane having at least one electrode And a step of laminating the electrophoretic medium to the backplane, wherein the electrophoretic medium is in direct contact with the backplane at a temperature at which the polymer binder flows. The display medium is formed by fixing the electrophoretic medium to the backplane. Seth (see, for example, Patent Document 1) 2) A composition suitable for sealing an electrophoresis cell, a) immiscible with the display fluid contained in the cell, and the specific gravity of the display fluid A composition comprising a solvent or a solvent mixture exhibiting a smaller specific gravity and b) a thermoplastic elastomer (see, for example, Patent Document 2), 3) dispersing particles that move at least by applying an electric field on the first substrate A display panel front plate (see, for example, Patent Document 3), in which a display body made of microcapsules dispersed and enclosed in a medium and a barrier layer are sequentially laminated, 4) a first substrate, and a second substrate A substrate, a partition provided on the first substrate, an electrophoretic material layer filled in a cell formed by the first substrate, the second substrate, and the partition, and the second Substrate and the partition wall A thin film layer provided between the thin film layer and the second substrate, and the sealing layer is formed on a surface facing the first substrate. An electrophoretic display device having a recess in a region in contact with the partition through the thin film layer (see, for example, Patent Document 4), 5) a light-transmitting substrate, and a volume resistivity when an alternating current of 100 Hz is applied Is the resistance value of the electrophoretic ink when the electrophoretic ink 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. For an electrophoretic display medium, comprising a polyvinylidene chloride film, a polyvinylidene fluoride film, a vinylidene chloride film, a vinylidene fluoride film, or the like, and a structure formed between the substrate and the sealing film. A sheet (see, for example, Patent Document 5) is known.

However, the technique described in Patent Document 1 is an electrophoretic display medium using a microcapsule layer, and is not an electrophoretic display medium using an electrophoretic ink, but is poured and fixed in a liquid state. Thus, it cannot be used for sealing electrophoretic ink, and is different from the present invention in the problem of the invention and its technical idea (configuration and operation and effect, the same applies hereinafter).
The technique described in Patent Document 2 described above is that after applying electrophoretic ink, a sealing liquid containing a thermoplastic elastomer having a specific gravity lower than that of electrophoretic ink is allowed to flow, and UV or heat is applied to form a film or seal. In this system, the electrophoretic ink to be used is limited, and this is not a film, but a liquid flow. Further, regarding the electrical connection with the electrode after film formation, As described in paragraph [0064], this is realized using an adhesive layer or an adhesive layer. In the configuration of the above-mentioned document 2 in which the adhesive layer is provided, there are problems such as loss of power because the adhesive layer or the adhesive layer also has resistance, and the conductive performance of the film decreases with time. The present invention is different from the present invention in the problem of the invention and its technical idea (configuration and its operational effects, the same applies hereinafter).

  The technique of the said patent document 3 provides a barrier layer on a microcapsule layer, and there exists description that an adhesive layer is further provided on a barrier layer. In addition, paragraph [0014] includes a statement that “if the barrier layer has adhesiveness by including a thermoplastic resin, the adhesive layer is not particularly required”. Is disclosed, but is completely different in the following points. The “barrier layer having adhesiveness” described in this document 3 is formed on a microcapsule sheet, whereas the present invention is an ink sealing film for sealing electrophoretic ink. . In order to function as a film for sealing ink, a certain thickness is required. With reference to the description in paragraph [0027] of the examples, the barrier layer described in Document 3 is “a barrier layer made of a silicon oxide film having a thickness of 50 nm was formed by a vacuum deposition method”. "It refers to what has formed a thin film structure by itself after molding, and those that cannot be practically separated from the molded substrate alone often use terms such as" film "or" layer " The barrier layer described in Document 3 is not a film. Further, the thickness of 50 nm is a thickness that cannot be bonded in the process after the barrier layer is formed first, and it can be said that the technical idea is different from the present invention.

The technology of Patent Document 4 includes a thin film layer provided between a second substrate and a partition, and a sealing layer provided between the thin film layer and the second substrate, and the sealing Since the layer is configured to have a recess in a region in contact with the partition wall through the thin film layer on the surface facing the first substrate, a double structure of the thin film layer and the sealing layer is obtained. Even in this configuration, since there is an electrical resistance, a power loss occurs, and there are problems in manufacturability and the like. Further, there is no detailed description on the means for laminating the substrate having the electrode layer, and the present invention is different from the present invention in terms of the technical problem and the technical idea, as in the case of Patent Document 3, as long as the adhesive layer is interposed. To do.
In the technique of Patent Document 5, the obtained electrophoretic display medium sheet improves unprecedented structural durability and display durability, but is laminated by bonding to an arbitrary substrate or the like. In the present situation, there is a power loss and further improvement is desired.

JP 2011-253201 A (Claims, Examples, etc.) JP-T-2005-509690 (Claims, Examples, etc.) JP 2003-270673 A (Claims, Examples, etc.) JP 2011-248065 A (Claims, Examples, etc.) JP 2012-098640 A (Claims, Examples, etc.)

  The present invention has been made in view of the above-mentioned problems and the present state of the art, and eliminates the need for an adhesive layer or the like for electrical connection with the electrode surface, and is superior in power efficiency and manufacturability. It is an object of the present invention to provide a display medium sheet and an electrophoretic display medium using the same.

As a result of diligent studies to solve the above-described conventional problems, the present inventor has obtained a light-transmitting substrate, electrophoretic ink, an ink sealing film that is disposed opposite to the substrate and seals the electrophoretic ink, and , A sheet for an electrophoretic display medium having a structure formed between a substrate and an ink sealing film, wherein the ink sealing film is made of a specific thermoplastic resin composition and has a specific physical property It has been found that by using a resin film, the above-mentioned sheet for electrophoretic display medium can be obtained, and this electrophoretic display medium sheet can be used without interposing an adhesive layer on a substrate having an electrode layer. The inventors have found that the above-described electrophoretic display medium can be obtained by laminating, and have completed the present invention.

That is, the present invention resides in the following (1) to (9).
(1) having a light-transmitting substrate, electrophoretic ink, an ink sealing film disposed opposite to the substrate and sealing the electrophoretic ink, and a structure formed between the substrate and the ink sealing film An electrophoretic display medium sheet, wherein the ink sealing film is composed of a thermoplastic resin composition containing at least a thermoplastic resin and a polymer type antistatic agent, and the resistance value of the ink sealing film is as described above. An electrophoretic display medium sheet comprising a thermoplastic resin film having a resistance value of 10 times or less of the electrophoretic ink.
(2) A pair of ink sealing films, electrophoretic ink, and the electrophoretic ink are sealed with a pair of ink sealing films opposed to each other, and a structure formed between the ink sealing films. A sheet for electrophoretic display media, wherein the pair of ink sealing films is composed of a thermoplastic resin composition containing at least a thermoplastic resin and a polymer antistatic agent, and the resistance of the ink sealing film portion A sheet for electrophoretic display media, comprising a thermoplastic resin film having a value of 10 times or less of the resistance value of the electrophoretic ink portion.
(3) The sheet for electrophoretic display media according to (1) or (2) above, wherein the ink sealing film has a volume resistivity of 1 × 10 ¹¹ Ω · cm or less.
(4) The sheet for electrophoretic display media according to any one of (1) to (3) above, wherein the polymer antistatic agent has a polyethylene oxide (PEO) chain.
(5) The thermoplastic resin composition containing a polymer-type antistatic agent further contains a conductive compound, as described in any one of (1) to (4) above, Sheet for electrophoretic display medium.
(6) The sheet for electrophoretic display media as described in (5) above, wherein the conductive compound is an ionic conductive compound.
(7) The sheet for electrophoretic display media according to any one of (1) to (6) above, wherein the ink sealing film has a thickness of 1 to 100 μm.
(8) On the ink-sealing film of the electrophoretic display medium sheet according to any one of (1) to (7), a substrate having an electrode layer is laminated without using an adhesive layer. An electrophoretic display medium characterized by the above.
(9) The electrophoretic display medium as described in (8) above, wherein the ink sealing film and the substrate having an electrode layer are laminated by heat fusion.

  According to the present invention, the ink sealing film is composed of a thermoplastic resin composition containing at least a thermoplastic resin and a polymeric antistatic agent, and the resistance value of the ink sealing film is that of the electrophoresis ink. When a thermoplastic resin film having a resistance value of 10 times or less is used, heat can be applied to the ink sealing film to generate adhesiveness, so an adhesive layer or the like is not required for electrical connection with the electrode surface. An electrophoretic display medium sheet excellent in power efficiency and manufacturability and an electrophoretic display medium using the same are provided.

It is a schematic longitudinal cross-sectional view which shows an example of embodiment of the sheet | seat for electrophoretic display media of this invention. It is a schematic longitudinal cross-sectional view explaining the process of laminating | stacking the board | substrate which has an electrode layer on the sheet | seat for electrophoretic display media of FIG. It is a schematic longitudinal cross-sectional view which shows an example of the electrophoretic display medium obtained from FIG. It is a schematic longitudinal cross-sectional view which shows the other example of embodiment of the sheet | seat for electrophoretic display media of this invention. It is a schematic longitudinal cross-sectional view explaining the process of laminating | stacking the board | substrate which has an electrode layer on the sheet | seat for electrophoretic display media of FIG. It is a schematic longitudinal cross-sectional view which shows an example of the electrophoretic display medium obtained from the sheet | seat for electrophoretic display media of FIG. (A) And (b) is each schematic longitudinal cross-sectional view explaining the other process of laminating | stacking the board | substrate which has an electrode layer on the sheet | seat for electrophoretic display media. It is each schematic longitudinal cross-sectional view explaining the other process of laminating | stacking the board | substrate which has an electrode layer on the sheet | seat for electrophoretic display media.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 3 show an example of an embodiment of the present invention, FIG. 1 is a schematic longitudinal sectional view showing an example of an electrophoretic display medium sheet, and FIG. 2 is an electrophoretic display medium sheet of FIG. FIG. 3 is a schematic longitudinal sectional view illustrating an example of an electrophoretic display medium obtained from FIG. 1. FIG. 3 is a schematic longitudinal sectional view illustrating a process of laminating a substrate having an electrode layer on the substrate.
As shown in FIG. 1, the sheet A for electrophoretic display medium of the present embodiment includes a substrate 10 having optical transparency, an electrophoretic ink 20, and an ink that is disposed opposite to the substrate 10 and seals the electrophoretic ink 20. It has the sealing film 30, and the structure 15 formed between the board | substrate 10 and the ink sealing film 30, The said ink sealing film 30 is a thermoplastic containing at least a thermoplastic resin and a polymeric antistatic agent. The resin composition is composed of a thermoplastic resin film having a resistance value of the ink sealing film of 10 times or less than the resistance value of the electrophoretic ink.

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 is not particularly limited and can be appropriately selected. 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 present embodiment, when the electrode substrate 10 is the front electrode substrate (when viewed from the arrow side in FIG. 1 (the same applies to FIGS. 3, 4 and 6 described later)), In order to visually recognize the display of characters and the like formed with the electrophoretic ink through 10, the base material 11 and the electrode layer 12 are formed of a light-transmitting material.

Structures 15, 15... Are erected on the light-transmitting substrate 10. The structure 15 can be formed using a resin material such as a PET film. For example, a plurality of cells (not shown) are formed by the structures 15, 15... By laser processing a synthetic resin such as a PET film having a certain thickness to form a square, hexagon, circle, or the like. can do. A plurality of cells can be formed by forming an insulating layer over the electrode layer 12 and then patterning the insulating layer using a photolithography method. In addition, it is also possible to form a thermoplastic resin on the electrode layer 12 and form a cell made of a cross-shaped structure 15 by a method such as hot embossing.
A plurality of cells (small chambers) are formed by the insulating structures 15, 15... Standing on the light-transmitting substrate 10, and these cells are separated by the standing structures 15. It 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 formed on the electrode substrate 10 are filled with the electrophoretic ink 20. As the filling of the electrophoretic ink 20, for example, coating with a die coater or the like, and the electrophoretic ink 20 disposed on an arbitrary portion of the electrode substrate may be spread by substantially contact with a bar coater, a doctor blade, a comma roll, or the like. Any method can be used as long as it is a printing method that uses screen printing or the like, or a method that can fill the cells with ink, such as ink jet or dispenser filling.

The electrophoretic ink 20 used in the present invention is not particularly limited. For example, any electrophoretic ink may be used as long as it contains at least one kind of electrophoretic particles and a solvent such as a solvent.
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 types to be used, and is preferably contained so as to be 20 to 80% by mass, more preferably, based on the total amount of electrophoretic ink. It is desirable to set it as 35-65 mass%.

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 contained so as to be 0.01 to 50.0% by mass with respect to the total amount of electrophoretic ink. More preferably, the content is preferably 0.5 to 30% by mass. As the charge control agent, various types used for electrophoretic display can be used.
The electrophoretic ink 20 used in the present invention can be adjusted to an electrophoretic ink having various characteristics by suitably combining the types of components constituting the electrophoretic ink and the content of each component.

In the present invention, the ink sealing film 30 can be formed (formed) from a thermoplastic resin composition containing at least a thermoplastic resin and a polymer antistatic agent, and the resistance value of the ink sealing film is as follows. It consists of a thermoplastic resin film that is 10 times or less the resistance value of the electrophoretic ink portion. Preferably, in terms of power efficiency at the time of rewriting, due to the structure of the rewriting machine (if the film resistance value is high, the voltage required for driving also increases, and as a result, the performance of the booster circuit mounted on the rewriting machine must be improved. The resistance value of the ink sealing film is not more than 5 times the resistance value of the electrophoretic ink portion, in particular, the resistance of the ink sealing film. When the value includes a single segment electrophoretic display medium of 1 pixel or less than the resistance value of the electrophoretic ink part, the lower limit is not particularly limited, but preferably the resistance of the ink sealing film It is desirable that the value is 0.1 times or more, more preferably 0.5 times or more the resistance value of the electrophoretic ink portion.
The ink sealing film 30 used in the present invention is made of a thermoplastic resin film having a resistance value as described above, and more preferably has a volume specific resistance of 1 × 10 ¹¹ Ω · cm or less, particularly a volume specific. When the resistance is 1 × 10 ¹⁰ Ω · cm or less and a single-segment electrophoretic display medium of one pixel is included, the lower limit is not particularly limited, but the volume resistivity is 1 × 10 ⁷ Ω · cm or more, It is particularly preferable that the volume resistivity is 1 × 10 ⁸ Ω · cm or more.
The ink sealing film 30 made of a thermoplastic resin film having a volume resistivity and a resistance value is composed of the thermoplastic resin species used in the thermoplastic resin composition, the polymer antistatic agent species, and the content and thickness thereof. The electrophoretic ink species to be used can be suitably combined, and can be prepared by combining, for example, the inclusion of a conductive compound species to be described later if necessary.
In the present invention, the method for measuring “volume resistivity” in the electrophoretic ink and ink sealing film refers to a value measured by an impedance measuring device. Further, the “resistance value” in the electrophoretic ink and the ink sealing film is calculated by resistance value = [(volume specific resistance × thickness) / area].

Examples of the thermoplastic resin that can be used include polyolefin (PO) resins such as homopolymers or copolymers containing ethylene, polyolefin elastomers, amorphous polyolefin resins (APO) such as cyclic polyolefins, polystyrene ( PS), ABS, SBS, SIS and other polystyrene resins or SEBS, SEPS, SEEPS, etc. hydrogenated styrene elastomers, polyvinyl chloride (PVC) resins, polyvinylidene chloride (PVDC) resins, polymethyl methacrylate ( PMMA), acrylic resins such as copolymer acrylic, polyester resins such as polyethylene terephthalate (PET), nylon 6, nylon 12, polyamide (PA) resins such as copolymer nylon, polyvinyl alcohol (PVA) resin, ethylene- Bi Polyvinyl alcohol resins such as nyl alcohol copolymer (EVOH), polyimide (PI) resin, polyetherimide (PEI) resin, polysulfone (PS) resin, polyethersulfone (PES) resin, polyamideimide (PAI) resin , Polyether ether ketone (PEEK) resin, polycarbonate (PC) resin, polyvinyl butyral (PVB) resin, polyarylate (PAR) resin, (meth) acrylate resin, and the like.
Preferably, polyethylene terephthalate (PET) or polycarbonate (PC) is used from the viewpoint of further exerting the effects of the present invention and resistance to the ink to be sealed.
The content of this thermoplastic resin is preferably 30 to 95% by mass, more preferably 50 to 90% by mass, based on the total amount of the thermoplastic resin composition.

  If the content of this thermoplastic resin is less than 30% by mass, the solvent resistance and fastness will decrease, whereas if it exceeds 95% by mass, the volume resistivity of the film will increase and the conductivity will increase. It does not develop and is not preferred.

Examples of the polymer antistatic agent that can be used include polyether ester amide (PEEA), polyether ester amide imide (PEAI), polyethylene glycol methacrylate copolymer, polyether amide imide, polyether ester, and polyethylene oxide. -Epichlorohydrin copolymer, polyethylene oxide-polypropylene oxide (PEO-PPO) copolymer, polyether olefin block copolymer and the like.
Preferably, from the viewpoint of forming a polymer solid electrolyte, the polymer antistatic agent used is desirably a polymer compound having a PEO (polyethylene oxide) chain as a conductive unit in the molecule. , Polyethylene glycol methacrylate copolymer, polyether ester amide block copolymer (PEEA), polyether ester amide imide copolymer (PEAI), polyethylene oxide-polypropylene oxide (PEO-PPO) copolymer, polyether olefin block The use of a copolymer is desirable.

  In addition to being a thermoplastic resin, the polymer type antistatic agent has a feature that it has a low volume resistivity and has a permanent antistatic effect even when used alone. Unlike the “low molecular weight antistatic agent” based on the principle of reducing resistance, it has the advantage of having antistatic properties and reliability.

The content of the polymer type antistatic agent is preferably 5 to 70% by mass, more preferably 10 to 50% by mass, based on the total amount of the thermoplastic resin composition.
If the content of the polymer type antistatic agent is less than 5% by mass, the conductivity may not be exhibited. On the other hand, if it exceeds 70% by mass, the solvent resistance and the fastness are deteriorated. Absent.

Furthermore, in the present invention, it is desirable that the thermoplastic resin composition contains a conductive compound together with the above-mentioned polymer type antistatic agent from the viewpoint of further improving the conductive performance and facilitating control of the conductive performance. .
Examples of the conductive compound that can be used include compounds having an alkali metal salt, an ether, or an ester bond.
Examples of the alkali metal salt include metal salts such as lithium, sodium, potassium, and magnesium, and metal salts of lithium and sodium are preferable. For example, lithium perchlorate, sodium perchlorate, sodium dodecylbenzene sulfonate, and lithium fluoroalkane sulfonate represented by [LiC _n F _{2n + 1} SO ₃ ], Li ₂ (C _n F _2n ) (SO ₃ ) ₂ , LiN (C _n F _{2n + 1} SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiN (CF ₃ CO) ₂ , LiC _n F _{2n + 1} CO ₂ , LiB (C ₆ H ₅ ) ₄ , LiClO ₄ , LiPF ₆ , fluorine-containing lithium salts such as LiAsF ₆ , LiSbF ₆ , and LiBF ₄ . In the above chemical formula, n is an integer.

Examples of the compound having an ether or ester bond include adipates, phthalates, and polyether polyols.
Among these conductive compounds, the inclusion of a polymer type antistatic agent and a synergistic effect on antistatic properties, the substrate (film) in addition to the case of using the polymer type antistatic agent alone It is preferable to use ion conductive compounds such as lithium and sodium metal salts such as the above-mentioned fluorine-containing lithium salts, more preferably bis (Trifluoromethanesulfonyl) imidolithium Li (CF ₃ SO ₂ ) ₂ N, tris (trifluoromethanesulfonyl) methidolithium Li (CF ₃ SO ₂ ) ₃ C, lithium trifluoromethanesulfonate Li (CF ₃ SO ₃ ) and the like are desirable. In particular, bis (trifluoromethanesulfonyl) imidolithium and trifluoro Lithium methanesulfonate is preferred.
Since lithium ions have the smallest ion radius and the highest degree of freedom of ion movement among alkali metals, it is assumed that lithium ions can quickly dissipate static electricity by ion conduction and attenuate the charged voltage.

The content of these conductive compounds is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, based on the total amount of the thermoplastic resin composition.
When the content of the conductive compound is less than 0.1% by mass, the effect of containing the conductive compound cannot be exhibited. On the other hand, when the content is more than 10% by mass, the conductive compound is uniformly dispersed in the film. Is difficult and undesirable.

  As the commercially available polymer antistatic agent used in the present invention, commercially available polymers can be used as various polymer antistatic agents, preferably commercially available as polymer antistatic agents containing an ion conductive compound. Polyether ester amide block copolymer containing trifluoromethanesulfonic acid Li (Li salt, ion conductive compound) [manufactured by Sanko Chemical Co., Ltd., trade name “Sanconol TBX-25 (Li salt concentration 5 mass%), TBX -65 (Li salt concentration 5% by mass), TBX-310 (Li salt concentration 10% by mass) ", a polyether olefin block copolymer containing sodium dodecyl benzan sulfonate (ionic conductive compound) (Sanyo Kasei Kogyo Co., Ltd.) Product name "Peletron HS", "Peletron PVH"), sodium dodecyl benzan sulfonate (ionic conductivity) Polyetheresteramide block copolymers containing compound) (manufactured by Sanyo Chemical Industries, Ltd., trade name "PELESTAT NC6321", "PELESTAT 230"), and the like.

  In the present invention, the thermoplastic resin composition containing at least the above-mentioned thermoplastic resin, polymer type antistatic agent, and the like, as long as the effect of the present invention is not impaired, the thermoplastic resin serving as the substrate and the high Addition of compatibilizers, as well as antioxidants, heat stabilizers, UV absorption to improve compatibility with molecular antistatic agents (homogeneous and good dispersion of polymeric antistatic agents in the substrate) Various additives such as an agent, a flame retardant, a flame retardant aid, a colorant, a pigment, an antibacterial / antifungal agent, a light fastener, and a plasticizer can be contained.

The ink sealing film 30 of the present invention is formed by molding the thermoplastic resin composition, specifically, a mixture obtained by simply mixing the above components by dry blending, or an extruder such as a twin-screw kneader. It can be obtained by using a melt-kneaded and pelletized material as a raw material for various molded products, forming a film by a T-die extrusion method, or performing a stretching process or an annealing process thereafter.
For example, the above mixture and pellets can be put into an extrusion molding machine, injection molding machine, etc., and processed into an ink sealing film having a suitable specific resistance and thickness, and a stretching process and an annealing process can be carried out. It can be processed into an ink sealing film having a specific resistance and thickness.

In the present invention, the thickness of the ink sealing film formed from the thermoplastic resin composition is preferably 1 μm or more, more preferably 5 μm or more, and further preferably 10 μm from the viewpoint of maintaining sealing performance. On the other hand, from the viewpoint of ensuring the bendability of the film and lowering the resistance value of the film, it is preferably 100 μm or less, more preferably 50 μm or less, and in the preferred range 1 to 100 μm, especially 10 ˜50 μm is desirable.
When the thickness of the ink sealing film 30 is less than 1 μm, the gas barrier property is insufficient and the solvent in the electrophoretic ink evaporates. On the other hand, when the thickness exceeds 100 μm, the resistance value of the ink sealing film is low. A high voltage is not preferable because a voltage is not sufficiently applied to the electrophoretic ink and display performance is deteriorated.

In the present invention, the ink sealing film 30 that seals the electrophoretic ink 20 having the above-described characteristics is, for example, as shown in FIG. By bonding, the target electrophoretic display medium sheet A can be obtained.
Specifically, reference numerals 16 and 16 in FIG. 1 are seal portions formed on the electrode substrate 10 so as to be in contact with the structures 15 and 15 that are the outermost peripheral portions in the display area. The seal portions 16 and 16 are formed of a thermoplastic, thermosetting, or photocurable precursor material by various printing methods (screen printing method, letterpress printing method, intaglio (gravure) printing), and a coating method using a dispenser. be able to. 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 the present embodiment, as shown in FIG. 1, 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 is provided for each structure 15 and the seal portion 16. The target electrophoretic display medium sheet A can be obtained by pasting on the upper surface of 16.

  In the present embodiment, the electrode substrate 10 filled with the electrophoretic ink 20 is attached to the upper surface of each structural body 15 and the seal portions 26 and 26 with the ink sealing film 30 having the above characteristics that is disposed so as to seal the electrophoretic ink. As an alignment method, for example, after aligning one end of the ink sealing film 30, the ink sealing film 30 is bonded to the upper surface of each structure 15, the seal portions 26, 26 by passing between rollers disposed opposite to each other. Then, the electrophoretic display medium sheet A shown in FIG. 1 can be obtained by curing by irradiating the seal portion with UV or by heating.

Further, the electrophoretic display medium of the present invention is obtained by laminating a substrate having an electrode layer on the ink sealing film 30 of the obtained electrophoretic display medium sheet A without interposing an adhesive layer. The electrophoretic display device can be obtained by providing a control unit and the like.
As a board | substrate which has an electrode layer, the structure etc. which provided the electrode layer 12 on the base material 11 used with the board | substrate 10 which has the above-mentioned light transmittance, etc. are mentioned, for example, ITO etc. on a transparent resin film, transparent glass, etc. A light-transmitting material formed by a deposition method such as a coating method, an ion plating method, a sputtering method, or the like can be used. Moreover, what formed the electroconductive material film (layer), such as a metal, on the surface of nonelectroconductive substances, such as a resin film, a resin plate, glass, ceramics, and a metal plate can also be used.

2 and 3 show an embodiment of an electrophoretic display medium B obtained using the electrophoretic display medium sheet A of FIG.
The substrate 14 having the electrode layer 13 is configured in the same manner as the substrate 11 having the viewing-side electrode layer 12 described above, for example.
As shown in FIGS. 2 and 3, the electrophoretic display medium B includes a substrate 14 having an electrode layer 13 on an ink sealing film 30 of the electrophoretic display medium sheet A of FIG. In this embodiment, the electrophoretic display medium can be manufactured by laminating without using an adhesive layer by heat fusion using an iron. To describe this lamination in detail, the ink sealing film 30 is composed of a thermoplastic resin composition containing at least a thermoplastic resin and a polymer antistatic agent, and the resistance value of the ink sealing film is determined by the electrophoretic ink. Therefore, the ink sealing film 30 is heated by the heat source 40 (the arrow in FIG. 2 indicates the heat from the heat source (FIGS. 5 and 7A described later)). In the same manner, the adhesive property can be generated, and the ink sealing film 30 and the substrate 14 having the electrode layer 13 can be fixed by thermal fusion, and the substrate 14 having the electrode layer 13 can be fixed. A conventional adhesive layer, adhesive layer, and the like are not required for electrical connection with the electrode surface, so that an electrophoretic display medium sheet excellent in power efficiency and manufacturability and an electrophoretic display medium using the same can be obtained. It made.

In the present embodiment, the heat source 40 is pressed from the viewing side. However, the heat source 40 may be pressed from the substrate 14 side having the electrode layer 13, and the temperature of the heat source 40 is set to each heat of the ink sealing film 30. The temperature varies depending on the heat melting temperature and thickness of the plastic resin type, the polymer type antistatic agent type, etc., the influence on the electrophoretic ink 30, the material type and thickness of the substrate 14 having the electrode layer 13 to be laminated, and the like. A temperature that is sufficient to bond, but not enough to melt the entire film, is preferred, and a range of 70-160 ° C is desirable.
Depending on the application (use application, rewriting method, etc.) of the electrophoretic display medium, another light-transmitting electrode, non-light-transmitting 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 of FIG. 1 according to the present invention configured as described above, a light-transmitting substrate, electrophoretic ink, and ink sealing that is disposed opposite to the substrate and seals the electrophoretic ink. An electrophoretic display medium sheet comprising a film and a structure formed between the substrate and the ink sealing film, wherein the ink sealing film is a heat containing at least a thermoplastic resin and a polymer antistatic agent. It is made of a thermoplastic resin composition, and the resistance value of the ink sealing film is made of a thermoplastic resin film that is 10 times or less than the resistance value of the electrophoretic ink. Therefore, an adhesive layer or the like is not required for electrical connection with the electrode surface, and an electrophoretic display medium sheet excellent in power efficiency and manufacturability can be obtained.

  In addition, the electrophoretic display medium obtained from the electrophoretic display medium sheet 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.

The resistance value of the ink sealing film calculated from the volume specific resistance of the ink sealing film 30 and the thickness of the sealing film is the resistance of the electrophoretic ink calculated from the volume specific resistance of the electrophoretic ink 20 and the thickness of the ink portion. If it exceeds 10 times (1 × 10) the resistance value, the voltage applied to the ink is remarkably lowered, which is not preferable. Therefore, it is desirable that the resistance value of the ink sealing film portion is lower than that of the electrophoretic ink. However, a panel having a plurality of pixels such as an active matrix panel or a segment panel is 0.1 times (1 ×) the resistance value of the electrophoretic ink calculated from the volume specific resistance of the electrophoretic ink 20 and the thickness of the ink portion. If it is lower than 10 ⁻¹ ), a voltage may be applied to adjacent pixels through the ink sealing film 30, which is not preferable. Accordingly, it is desirable that the resistance value of the ink sealing film part is lower than that of the electrophoretic ink, and the electrophoretic ink 20 having a volume specific resistance and a resistance value more suitable for the volume specific resistance and resistance value of the ink sealing film 30 is prepared. It can be finely prepared by combining suitable electrophoretic particle species, solvent species, and the like. However, when segment display is not performed, that is, when only one pixel is used, the lower limit value of the volume specific resistance of the ink sealing film 30 is not particularly limited.

4 to 6 are schematic diagrams showing an outline of an electrophoretic display medium sheet C showing an example of another embodiment of the present invention, and an electrophoretic display medium D using the sheet. In addition, the same structure as embodiment of FIGS. 1-3 is displayed on a drawing, and the description is abbreviate | omitted.
As shown in FIG. 4, the electrophoretic display medium sheet C of the present embodiment includes a pair of ink sealing films 30, 30, an electrophoretic ink 20, and a pair of inks that are arranged to face each other. It seals with the sealing films 30 and 30, and has the structures 15, 15 ... formed between the ink sealing films 30 and 30, and the pair of ink sealing films 30 and 30 is at least a thermoplastic resin. And a thermoplastic resin composition containing a polymer-type antistatic agent, wherein the resistance value of the ink sealing film is 10 times or less than the resistance value of the electrophoretic ink. Thus, it is different from the electrophoretic display medium sheet A of the embodiment of FIG.
In the electrophoretic display medium sheet A of the embodiment of FIG. 1, the substrate 12 having the electrode layer 11 is provided only on the viewer side, but in this embodiment, the rear side is opposite to the viewer side. The ink sealing film 30 is also provided on the side. The structures 15, 15..., The seal portion 16, etc. are formed on the ink sealing film 30 on the viewing side in the same manner as in the embodiment of FIG. The ink sealing films 30 and 30 are also formed in the same manner as the electrophoretic display medium sheet A of the embodiment of FIG. Furthermore, the heat source 40 is configured to be pressed from both the viewing side and the rear side opposite to the viewing side.

5 and 6 show an embodiment of an electrophoretic display medium D obtained by using the electrophoretic display medium sheet C of FIG.
5 and 6, the electrophoretic display medium D is ironed from both sides of the substrate 14 having the electrode layers 13 on the pair of ink sealing films 30 and 30 of the electrophoretic display medium sheet C of FIG. The electrophoretic display medium can be manufactured by laminating without using an adhesive layer by heat fusion using a heat source 40 such as the above. In this embodiment, the pair of ink sealing films 30 and 30 is composed of a thermoplastic resin composition containing at least a thermoplastic resin and a polymer type antistatic agent, and the resistance value of the ink sealing film is equal to the electrical resistance. Since it is a thermoplastic film having a resistance value of 10 times or less of the migration ink, it is possible to generate adhesiveness by applying heat to the ink sealing film, and the pair of ink sealing films 30, 30 and the electrode layer 13. It can be fixed to the substrate 14 having heat resistance by heat fusion, and a conventional adhesive layer, adhesive layer, or the like is not required for electrical connection with the electrode surface of the substrate 14 having the electrode layer 13. Thus, an electrophoretic display medium sheet having excellent properties and an electrophoretic display medium using the same can be obtained.

7 and 8 show other forms of the heat source 40 used when the ink sealing film 30 is thermally fused to the electrophoretic display medium sheet in the present invention.
7A, the heat source 40 is a rotary roller type, and the electrode layer 13 is formed on the ink sealing film 30 in order from the left side to the right side in the drawing while pressing the rotary heat source 40 from the viewing side. In this embodiment, the electrophoretic display media B and D shown in FIG. 3 or FIG. 6 can be manufactured.

  FIG. 7B shows a rotary process of bonding the structure 15 of the ink sealing film 30 to the upper surface of the seal portions 16 and 16 (fixing process) and fixing the substrate 14 having the electrode layer 13. This is a form that is performed almost simultaneously by the heat source 40. After the film surface is fused by the rotary heat source 40, the structure 15 and the seal parts 16 and 16 are immediately bonded to the top surface (from left to right in the drawing). The electrophoretic display media B and D shown in FIG. 3 or FIG. 6 can be manufactured.

  FIG. 8 shows a form in which the substrate 14 having the electrode layer 13 is fixed to the ink sealing film 30 by heat fusion and stacked in a heat source 40 such as an oven. Electrophoretic display media B and D can be produced. In the case of using this oven-type heat source, the substrate 14 having the electrode layer 13 on the ink sealing film 30 is formed by holding with a vise and applying pressure in the direction of the arrow in the drawing. It may be fixed by heat fusion.

  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 thereto.

(Example 1, based on FIGS. 1 to 3)
An electrophoretic display medium sheet and an electrophoretic display medium were obtained by the following steps 1) to 4).
1) A step of forming a plurality of cells made of an insulating structure on an electrode substrate A 100 μm-thick PET sheet formed as an electrode substrate with an ITO film, which is a transparent material, having a surface resistance of about 100Ω / □ 6 × 10 cm) (hereinafter referred to as “ITO-PET”).
On this electrode substrate, a photosensitive resin sheet made of an epoxy resin is bonded, exposed to UV, and alkali-developed to form a plurality of lattice-shaped cells (height 20 μm, cell size pitch) made of insulating structures. 300 μm, a gap of 20 μm, and an aperture ratio of 87%) were formed in the range of 30 × 30 mm of the PET film.

2) Step of filling the cell with electrophoresis ink <Preparation of white fine particles>
2 parts by mass of hydrophobizing silicone oil (KF99, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 100 parts by mass of titanium oxide (CR50, primary average particle size: 250 nm, manufactured by Ishihara Sangyo Co., Ltd.) and stirred uniformly with a kneader. . Thereafter, baking was performed at 150 ° C. for 20 minutes.
<Preparation of black fine particle solution>
Polyoxyethylene (6) sorbitan tetraoleate (dispersing agent, manufactured by Wako Pure Chemical Industries, Ltd.) is added to crosslinked acrylic copolymer particles (Labcoroll 220MD, average particle size: 9 μm, manufactured by Dainichi Seika Kogyo Co., Ltd.) containing carbon black. The resulting mixture was dispersed in normal dodecane (liquid phase dispersion medium, refractive index: 1.42, manufactured by Wako Pure Chemical Industries, Ltd.), and coarse particles were removed through a filter to obtain a black fine particle solution. The solid content concentration of this solution was measured with a measuring instrument (manufactured by METTLER TOLEDO), and the solid content concentration was adjusted to 25% by mass.
10 parts by weight of the above white fine particles and 80 parts by weight of the black fine particle solution were mixed and subjected to ultrasonic dispersion for 1 hour to prepare an electrophoretic ink.
This electrophoretic display solution had a volume specific resistance of 4.6E9 Ω · cm and a dielectric constant of 3.2. The measurement was performed using an LCR meter (product name: ZM2410, manufactured by NF Circuit Block) and a liquid measurement electrode LP-05 (manufactured by Kawaguchi Electric Co., Ltd.) (the same applies hereinafter).
The electrophoretic ink was filled in the cell with a coater.
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.

4) The process of bonding an electrode substrate and an ink sealing film The ink sealing film 30 was produced with the T-die extrusion method using the thermoplastic resin composition of the following composition.
Thermoplastic resin composition:
PET resin (Kuraray Co., Ltd., KS760K-H): 57.5% by mass
Polyether ester amide block copolymer containing trifluoromethanesulfonic acid Li (2.13 mass%): (trade name “Sanconol TBX-65” manufactured by Sanko Chemical Co., Ltd.) 42.5 mass%
When the volume resistivity of this thermoplastic film was measured using Hiresta (Mitsubishi Chemical Analytech Co., Ltd.), it was 5.0E9 Ω · cm at a measurement voltage of 100V.
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 irradiating the seal portion with UV, An electrophoretic display medium sheet was obtained.

The ink area Si at this time was Si = 4 cm × 5 cm = 20 cm ² , and the ink thickness Ti was Ti = 20 μm. Therefore, when the ink resistance value Ri was calculated, Ri = 460 kΩ. .
Similarly, the area Sf of the ink sealing film that touches the ink is Sf = 4 cm × 5 cm = 20 cm ² , and the thickness Tf of the ink sealing film was Tf = 50 μm. When the resistance value Rf of the film was calculated, Rf = 1250 kΩ, and the resistance value Rf of the ink sealing film was about 2.72 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.
Furthermore, the segmented electrode substrate (copper is laminated on the PEN film and the pattern is formed by etching) is brought into contact with the sealing film surface of the electrophoretic display sheet on the obtained electrophoretic display medium sheet, and an iron heated to 100 ° C. The electrophoretic display sheet was pressed and adhered to obtain an electrophoretic display medium.
A display was obtained when 0 ms as Vmid was applied to the common electrode of the obtained electrophoretic display medium, -60 V as VL was applied to the white display portion of the electrode substrate, and +60 V was applied as VH to the black display portion for 500 ms. When measured with a spectrocolorimeter SC-T (manufactured by Suga Test Instruments Co., Ltd.), the white reflectance was 37.7% and the black reflectance was 3.8%.

(Example 2, which can be displayed in the case of only one pixel, in accordance with FIGS. 1 to 3)
In the steps 1) to 4) of Example 1 above, the step 4) was changed to the following step to produce an electrophoretic display medium sheet.
4) The process of bonding an electrode substrate and an ink sealing film The ink sealing film 30 was produced with the T-die extrusion method using the thermoplastic resin composition of the following composition.
Thermoplastic resin composition:
PET resin (Kuraray Co., Ltd., KS760K-H): 50.0% by mass
Polyether ester amide block copolymer containing trifluoromethanesulfonic acid Li (2.5% by mass): (trade name “Sanconol TBX-65” 50.0% by mass, manufactured by Sanko Chemical Co., Ltd.)
When the volume resistivity of this thermoplastic film was measured using Hiresta (Mitsubishi Chemical Analytech Co., Ltd.), it was 1.69E8 Ω · cm at a measurement voltage of 100V.
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 irradiating the seal portion with UV, An electrophoretic display medium sheet was obtained.

The ink area Si at this time was Si = 4 cm × 5 cm = 20 cm ² , and the ink thickness Ti was Ti = 20 μm. Therefore, when the ink resistance value Ri was calculated, Ri = 460 kΩ. .
Similarly, the area Sf of the ink sealing film that touches the ink is Sf = 4 cm × 5 cm = 20 cm ² , and the thickness Tf of the ink sealing film was Tf = 50 μm. When the resistance value Rf of the film was calculated, Rf = 42.2 kΩ, and the resistance value Rf of the ink sealing film was about 0.09 times the resistance value Ri of the ink.

(Performance evaluation of the electrophoretic display medium of Example 2)
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.
Furthermore, the segmented electrode substrate (copper is laminated on the PEN film and the pattern is formed by etching) is brought into contact with the sealing film surface of the electrophoretic display sheet on the obtained electrophoretic display medium sheet, and an iron heated to 100 ° C. The electrophoretic display sheet was pressed and adhered to obtain an electrophoretic display medium.
When 0 m as Vmid was applied to the common electrode of the obtained electrophoretic display medium, -60 V as VL was applied to the white display portion of the electrode substrate, and +60 V was applied as VH to the black display portion for 500 ms, no display was obtained.
A white display was obtained when 0 ms as Vmid was applied to the common electrode of the obtained electrophoretic display medium and −60 V was applied as VL to the white display portion and the black display portion of the electrode substrate for 500 ms. Further, when 0 V as Vmid was applied to the common electrode of the obtained electrophoretic display medium and +60 V was applied as VH to the white display portion and the black display portion of the electrode substrate for 500 ms, a black display was obtained.
When measured with a spectrocolorimeter SC-T (manufactured by Suga Test Instruments Co., Ltd.), the white reflectance was 39.8%, and the black reflectance was 4.2%.

(Comparative example 1, FIGS. 1 to 3 compliant, resistance value is too high)
An ink sealing film 30 was prepared by a T-die extrusion method using a thermoplastic resin composition having the following composition.
Thermoplastic resin composition:
PET resin (Kuraray Co., Ltd., KS760K-H): 60.0% by mass
Polyether ester amide block copolymer containing Li (2.0% by mass) trifluoromethanesulfonic acid: (trade name “Sanconol TBX-65” 40.0% by mass, manufactured by Sanko Chemical Co., Ltd.)
When the volume resistivity of this thermoplastic film was measured using Hiresta (Mitsubishi Chemical Analytech), it was 2.45E10 Ω · cm at a measurement voltage of 100V.
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 irradiating the seal portion with UV, An electrophoretic display medium sheet was obtained.
The ink area Si at this time was Si = 4 cm × 5 cm = 20 cm ² , and the ink thickness Ti was Ti = 20 μm. Therefore, when the ink resistance value Ri was calculated, Ri = 460 kΩ. .
Similarly, the area Sf of the ink sealing film that touches the ink is Sf = 4 cm × 5 cm = 20 cm ² , and the thickness Tf of the ink sealing film was Tf = 50 μm. When the resistance value Rf of the film was calculated, Rf = 6125 kΩ, and the resistance value Rf of the ink sealing film was about 13.32 times the resistance value Ri of the ink.
Furthermore, the segmented electrode substrate (copper is laminated on the PEN film and the pattern is formed by etching) is brought into contact with the sealing film surface of the electrophoretic display sheet on the obtained electrophoretic display medium sheet, and an iron heated to 100 ° C. The electrophoretic display sheet was pressed and adhered to obtain an electrophoretic display medium.
When 0 m as Vmid was applied to the common electrode of the obtained electrophoretic display medium, -60 V as VL was applied to the white display portion of the electrode substrate, and +60 V was applied as VH to the black display portion for 500 ms, no display was obtained.
Even when 0 V as Vmid is applied to the common electrode of the obtained electrophoretic display medium and −60 V is applied as VL to the white display portion and the black display portion of the electrode substrate for 500 ms, VH is applied to the white display portion and the black display portion of the electrode substrate. Even when +60 V was applied for 500 ms, the display did not change.

(Example 3, based on FIGS. 4 to 6)
In Example 1 above, a plurality of lattice-like cells made of an insulating structure are bonded to an ink-sealing film 30 by a photosensitive resin sheet made of an acrylic resin, exposed to UV, and alkali-developed ( A height of 20 μm, a pitch of 300 μm, a gap of 20 μm, and an aperture ratio of 87%) was formed in the range of 30 × 30 cm of the ink sealing film 30. The cell was filled with the electrophoretic ink of Example 1 using a coater. Further, a UV curable resin was dropped onto the outer peripheral portion (display area) of the cell using a dispenser to form a seal portion. After aligning one end of the ink sealing film 30 to the electrode substrate filled with the electrophoretic ink thus obtained, it is pasted by passing between rollers placed opposite to each other, and then UV is applied to the seal portion. Was cured by irradiation to obtain an electrophoretic display medium sheet. In addition, when the volume specific resistance of the ink sealing film 30 is measured using an impedance measuring device Hiresta (manufactured by Mitsubishi Chemical Analytech Co., Ltd.), it is 5.0E9 Ω · cm at a measurement voltage of 100 V, and the resistance value of the ink sealing film is When calculated in the same manner as in Example 1, the resistance value of the film was about 2.72 times the resistance value of the ink.

(Performance evaluation of the electrophoretic display medium of Example 3)
No bubbles were mixed in the display area of each electrophoretic display medium sheet obtained in Example 3, and the distance between the electrode and the ink sealing film was uniform.
Furthermore, the segmented electrode substrate (copper is laminated on the PEN film and the pattern is formed by etching) is brought into contact with the sealing film surface of the electrophoretic display sheet on the obtained electrophoretic display medium sheet, and an iron heated to 100 ° C. An electrophoretic display medium was obtained by pressing and bonding from the electrophoretic display sheet side.
A display was obtained by applying 0 ms as Vmid to the common electrode using the obtained electrophoretic display medium, -60 V as VL to the white display portion of the electrode substrate, and +60 V as VH to the black display portion for 500 ms. When measured with a spectrocolorimeter SC-T (manufactured by Suga Test Instruments Co., Ltd.), the white reflectance was 36.2%, and the black reflectance was 4.5%.

DESCRIPTION OF SYMBOLS 10 Electrode substrate 11 Base material 12 Electrode layer 13 Base material 14 Electrode layer 15 Structure 16 Seal part 20 Electrophoretic ink 30 Ink sealing film 40 Heat source

  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)

  An electrophoretic display having a light-transmitting substrate, electrophoretic ink, an ink sealing film disposed opposite to the substrate and sealing the electrophoretic ink, and a structure formed between the substrate and the ink sealing film A sheet for a medium, wherein the ink sealing film is composed of a thermoplastic resin composition containing at least a thermoplastic resin and a polymer type antistatic agent, and the resistance value of the ink sealing film is the electrophoretic ink. A sheet for electrophoretic display media, comprising a thermoplastic resin film having a resistance value of 10 times or less.   Electrophoresis comprising a pair of ink sealing films, electrophoretic ink, and a structure formed between the ink sealing films while sealing the electrophoretic ink with a pair of ink sealing films opposed to each other A sheet for a display medium, wherein the pair of ink sealing films is composed of a thermoplastic resin composition containing at least a thermoplastic resin and a polymer-type antistatic agent, and the resistance value of the ink sealing film is as described above. An electrophoretic display medium sheet comprising a thermoplastic resin film having a resistance value of 10 times or less of the electrophoretic ink. The electrophoretic display medium sheet according to claim 1, wherein the ink sealing film has a volume resistivity of 1 × 10 ¹¹ Ω · cm or less.   The sheet for an electrophoretic display medium according to claim 1, wherein the polymer type antistatic agent has a polyethylene oxide (PEO) chain.   The sheet for an electrophoretic display medium according to claim 1, wherein the thermoplastic resin composition containing the polymer type antistatic agent further contains a conductive compound. .   6. The electrophoretic display medium sheet according to claim 5, wherein the conductive compound is an ion conductive compound.   The electrophoretic display medium sheet according to claim 1, wherein the ink sealing film has a thickness of 1 to 100 μm.   A substrate having an electrode layer is laminated on the ink-sealing film of the electrophoretic display medium sheet according to any one of claims 1 to 7 without interposing an adhesive layer. Electrophoretic display medium.   9. The electrophoretic display medium according to claim 8, wherein the ink sealing film and the substrate having the electrode layer are laminated by heat fusion.

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