JP2008009422A - Particle for display medium, and panel for displaying information - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide particles for display media having proper retention characterists of charged amount, which particles can eliminate the trouble of deterioration in a display performance, such as decrease in image concentration, and deterioration in drive performance, and to provide a panel for displaying information that uses the same. <P>SOLUTION: The particles 3 constitute the display media used for the panel for displaying information, wherein the panel encloses the display medium between two substrates, either of which is at least transparent; and the panel displays information such as images by applying the electric field to the display media to move the display media. The volume resistivity of resin that constitutes the particles 3 is ≥1×10<SP>14</SP>Ω cm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is used for an information display panel that displays information such as an image by moving a display medium by enclosing a display medium between two substrates, at least one of which is transparent, and applying an electric field to the display medium. The present invention relates to particles constituting a display medium and an information display panel using the particles.

  As an information display device that replaces a liquid crystal (LCD), an information display device using a technique such as an electrophoresis method, an electrochromic method, a thermal method, or a two-color particle rotation method has been proposed.

  Compared to LCDs, these conventional technologies have advantages such as a wide viewing angle close to that of ordinary printed materials, low power consumption, and a memory function. It is considered as a technology that can be used for mobile phones, and is expected to expand to information display for mobile terminals, electronic paper, and the like. Particularly recently, an electrophoretic method in which a dispersion liquid composed of dispersed particles and a solution is encapsulated and disposed between opposing substrates has been proposed and is expected.

  However, the electrophoresis method has a problem that the response speed becomes slow due to the viscous resistance of the liquid because the particles migrate in the liquid. In addition, since particles with high specific gravity such as titanium oxide are dispersed in a solution with low specific gravity, it is easy to settle, and it is difficult to maintain the stability of the dispersed state, and there is a problem that the stability of repeated information display is lacking. ing. Even when microencapsulation is performed, the cell size is set to the microcapsule level, and the above-described drawbacks are hardly made to appear, and the essential problems are not solved at all.

As one method for solving the above-described problem, an image is moved by enclosing a display medium between gas cavities between two substrates, at least one of which is transparent, and applying an electric field to the display medium. An information display panel that displays such information is known (Patent Document 1).
International Publication WO2005 / 062112 Pamphlet

  In the information display panel described above, the particles constituting the display medium (display medium particles) have different charge retention properties depending on the type of resin particles as the main component thereof. In an information display panel using a display medium composed of resin particles, there has been a problem that problems such as a deterioration in display state such as a decrease in image density and a deterioration in driving performance occur.

  The object of the present invention is to eliminate the above-mentioned problems and obtain particles for a display medium having good charged state retention characteristics. When an information display panel is configured using the particles, the image density decreases. It is an object of the present invention to provide a display medium particle and an information display panel using the same, which can eliminate problems such as deterioration in display state and drive performance.

The particles for display medium of the present invention are information for displaying information such as images by moving the display medium by enclosing the display medium between two transparent substrates at least one and applying an electric field to the display medium. In the particles constituting the display medium used for the display panel, the volume resistivity of the resin constituting the particles is 1 × 10 ¹⁴ Ω · cm or more.

  As a preferred example of the particles for display medium of the present invention, the decay rate of the particle charge amount is 0.3 μC / g · day or less when left for 30 days after being initially charged to 20 μC / g. .

  In addition, the information display panel of the present invention displays information such as images by moving the display medium by enclosing the display medium between two substrates, at least one of which is transparent, and applying an electric field to the display medium. In the information display panel, the above-described particles for a display medium are used as a display medium.

According to the present invention, an information display panel for displaying information such as an image by moving a display medium by enclosing the display medium between two substrates, at least one of which is transparent, and applying an electric field to the display medium. In the particles constituting the display medium used in the above, by using the particles for the display medium in which the volume resistivity of the resin constituting the particles is 1 × 10 ¹⁴ Ω · cm or more, the display state deteriorates such as a decrease in image density, It is possible to obtain an information display panel that can eliminate problems such as deterioration in driving performance.

  First, the basic configuration of the information display panel of the present invention will be described. In the information display panel of the present invention, an electric field is applied to the display medium sealed between the gas cavities between two opposing substrates. In accordance with the applied electric field direction, the charged display medium is attracted by the force of the electric field or the Coulomb force, and the moving direction of the display medium is switched by the change in the electric field direction, whereby information such as an image is displayed. Therefore, it is necessary to design the information display panel so that the display medium can move uniformly and maintain the stability when the display information is rewritten or when the display information is continuously displayed. Here, as the force applied to the particles constituting the display medium, in addition to the force attracting each other by the Coulomb force between the particles, an electric mirror image force between the electrode and the substrate, an intermolecular force, a liquid cross-linking force, gravity and the like can be considered.

  An example of an information display panel that is an object of the present invention will be described with reference to FIGS. 1 (a) and (b) to FIGS. 3 (a) and 3 (b).

  In the example shown in FIGS. 1A and 1B, at least two kinds of display media 3 (here, white display medium particles 3Wa) having at least one kind of particles and having different optical reflectance and charging characteristics. A white display medium 3W composed of a group of particles and a black display medium 3B composed of a group of particles 3Ba for black display medium) are perpendicular to the substrates 1 and 2 according to the electric field applied from the outside of the substrates 1 and 2. The black display medium 3B is visually recognized by the observer and black display is performed, or the white display medium 3W is visually recognized by the observer and white display is performed. In the example shown in FIG. 1B, in addition to the example shown in FIG. 1A, a partition 4 is provided between the substrates 1 and 2, for example, in the form of a lattice to form a cell. In addition, in FIG. 1B, the partition in front is omitted.

  In the example shown in FIGS. 2 (a) and 2 (b), at least two or more types of display media 3 (here, white display medium particles 3Wa) having at least one or more types of particles and having different optical reflectance and charging characteristics are used. Between the electrode 5 provided on the substrate 1 and the electrode 6 provided on the substrate 2 is a voltage between the electrode 5 provided on the substrate 1 and the electrode 6 provided on the substrate 2. In accordance with the electric field generated by applying, the substrate is moved perpendicularly to the substrates 1 and 2 and the black display medium 3B is visually recognized by the observer to display black, or the white display medium 3W is provided to the observer. A white display is made by visual recognition. In the example shown in FIG. 2B, a cell is formed by providing partition walls 4 between the substrates 1 and 2, for example, in a lattice shape. Further, in FIG. 2 (b), the front partition is omitted.

In the example shown in FIGS. 3A and 3B, the display medium 3 (in this case, from the particle group of white display medium particles 3Wa) having at least an optical reflectance and a charging property composed of at least one kind of particles. The white display medium 3W is moved in a direction parallel to the substrates 1 and 2 in accordance with an electric field generated by applying a voltage between the electrode 5 and the electrode 6 provided on the substrate 1 to display a white color. The medium 3W is visually recognized by the observer and white display is performed, or the color of the electrode 6 or the substrate 1 is visually recognized by the observer and the color of the electrode 6 or the substrate 1 is displayed. In the example shown in FIG. 3B, for example, a lattice-shaped partition wall 4 is provided between the substrates 1 and 2 to form a cell. Moreover, in FIG.3 (b), the partition in front is abbreviate | omitted.
The electrode may be provided outside the substrate or may be provided so as to be embedded inside the substrate.

  When the information display panel is driven, the positive and negative white display medium and the black display medium are triboelectrically charged in the panel, so that the equilibrium charge amount of each display medium can be maintained. However, when driving of the information display panel is stopped, the charge of the display medium inside the panel is attenuated, and there is a concern that the display performance of the information display panel may deteriorate due to a long-term neglect state. The

A feature of the present invention is that a resin having a volume specific resistance of 1 × 10 ¹⁴ Ω · cm or more is selected as a resin used when producing particles constituting the display medium 3 used in the information display panel described above. The material can be designed so that the charge decay rate of the display medium 3 is 0.3 μC / g · day or less, so that the display medium 3 with an initial charge amount of 20 μC / g can be left for 30 days. On the other hand, since the charge amount can be maintained at 10 μC / g or more, it has been found that excellent charge amount retention characteristics are exhibited. Therefore, according to the information display panel using the display medium particles of the present invention as the display medium 3, it is possible to effectively prevent deterioration of the display state and drive characteristics such as significant deterioration of image density.

The upper limit of the volume resistivity of the resin constituting the display medium particle of the present invention is not particularly limited from the viewpoint of maintaining the charge amount. Actually, even if the volume resistivity is to be increased, the range of the volume resistivity obtained by the type of resin used and the manufacturing method is determined. In either case, the volume resistivity currently obtained is about 1 × 10 ¹⁶ Ω · cm, and is determined within that range.

  Hereinafter, each member which comprises the information display panel of this invention is demonstrated.

  As for the substrate, at least one substrate is the transparent substrate 2 from which the color of the display medium can be confirmed from the outside of the information display panel, and a material having high visible light transmittance and good heat resistance is preferable. The substrate 1 may be transparent or opaque. Examples of substrate materials include polymer sheets such as polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyethylene, polycarbonate, polyimide, and acrylic, flexible materials such as metal sheets, and glass and quartz. An inorganic sheet having no flexibility is mentioned. The thickness of the substrate is preferably from 2 to 5000 μm, more preferably from 5 to 2000 μm. If it is too thin, it will be difficult to maintain the strength and the spacing uniformity between the substrates, and if it is thicker than 5000 μm, it will be a thin information display panel. Is inconvenient.

As an electrode forming material when an electrode is provided on an information display panel as required, metals such as aluminum, silver, nickel, copper, and gold, indium tin oxide (ITO), indium oxide, indium zinc oxide (IZO) Conductive metal oxides such as conductive tin oxide, antimony tin oxide (ATO), and conductive zinc oxide, and conductive polymers such as polyaniline, polypyrrole, and polythiophene are exemplified and used as appropriate. As a method for forming the electrode, sputtering, vacuum deposition, CVD (chemical vapor deposition), and a method of laminating a metal foil (for example, rolled copper foil)
A method of forming a thin film by a coating method or a method of applying a conductive agent mixed with a solvent or a synthetic resin binder is used. The electrode provided on the display surface side substrate 2 which is on the viewing side and needs to be transparent needs to be transparent, but the electrode provided on the back side substrate 1 does not need to be transparent. In any case, the above-mentioned material that can be patterned and is electrically conductive can be suitably used. In addition, the electrode thickness should just be sufficient if electroconductivity is ensured and there is no trouble in light transmittance, and 0.01-10 micrometers, Preferably 0.05-5 micrometers is suitable. The material and thickness of the electrode provided on the back side substrate 1 are the same as those of the electrode provided on the display surface side substrate described above, but need not be transparent. In this case, the external voltage input may be superimposed with direct current or alternating current.

The shape of the partition walls 4 provided on the substrate as required is appropriately set appropriately depending on the type of display medium involved in display, the shape and arrangement of electrodes to be arranged, and is not limited in general. The height of the partition is adjusted to 100 to 100 μm, preferably 3 to 50 μm, and the height of the partition wall to 10 to 100 μm, preferably 10 to 50 μm.
In forming the partition wall, a both-rib method in which ribs are formed on each of the opposing substrates 1 and 2 and then bonded, and a single-rib method in which ribs are formed only on one substrate are conceivable. In the present invention, any method is preferably used.
As shown in FIG. 4, the cells formed by the partition walls made up of these ribs are exemplified by a square shape, a triangular shape, a line shape, a circular shape, and a hexagonal shape as viewed from the plane of the substrate. And a mesh shape. It is better to make the portion corresponding to the cross section of the partition wall visible from the display surface side (the area of the cell frame) as small as possible, and the display state becomes clearer.
Examples of the method for forming the partition include a mold transfer method, a screen printing method, a sand blast method, a photolithography method, and an additive method. Any of these methods can be suitably used for the information display panel of the present invention, and among these, a photolithography method using a resist film and a mold transfer method are suitably used.

Next, display medium particles (hereinafter also referred to as particles) constituting the display medium in the information display panel of the present invention will be described. The display medium particles are used as they are as they are, which are composed of the display medium particles alone or in combination with other particles as a display medium.
The base particles can contain a charge control agent, a colorant, an inorganic additive, and the like, if necessary, in the resin as the main component, as in the conventional case. In the present invention, the volume resistivity of the resin as the main component needs to be 1 × 10 ¹⁴ Ω · cm or more. Examples of resins, charge control agents, colorants, and other additives will be given below.

  Examples of the resin include urethane resin, urea resin, acrylic resin, polyester resin, acrylic urethane resin, acrylic urethane silicone resin, acrylic urethane fluororesin, acrylic fluororesin, silicone resin, acrylic silicone resin, epoxy resin, polystyrene resin, styrene Acrylic resin, polyolefin resin, butyral resin, vinylidene chloride resin, melamine resin, phenol resin, fluororesin, polycarbonate resin, polysulfone resin, polyether resin, polyamide resin and the like can be mentioned, and two or more kinds can be mixed. In particular, acrylic urethane resin, acrylic silicone resin, acrylic fluororesin, acrylic urethane silicone resin, acrylic urethane fluororesin, fluororesin, and silicone resin are suitable from the viewpoint of controlling the adhesive force with the substrate.

  The charge control agent is not particularly limited. Examples of the negative charge control agent include salicylic acid metal complexes, metal-containing azo dyes, metal-containing oil-soluble dyes (including metal ions and metal atoms), and quaternary ammonium salt systems. Examples thereof include compounds, calixarene compounds, boron-containing compounds (benzyl acid boron complexes), and nitroimidazole derivatives. Examples of the positive charge control agent include nigrosine dyes, triphenylmethane compounds, quaternary ammonium salt compounds, polyamine resins, imidazole derivatives, and the like. In addition, metal oxides such as ultrafine silica, ultrafine titanium oxide, ultrafine alumina, nitrogen-containing cyclic compounds such as pyridine and derivatives and salts thereof, various organic pigments, resins containing fluorine, chlorine, nitrogen, etc. are also charged. It can also be used as a control agent.

  As the colorant, various organic or inorganic pigments and dyes as exemplified below can be used.

Examples of the black colorant include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon and the like.
Examples of blue colorants include C.I. I. Pigment blue 15: 3, C.I. I. Pigment Blue 15, Bituminous Blue, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Phthalocyanine Blue, Metal-free Phthalocyanine Blue, Phthalocyanine Blue Partial Chlorides, Fast Sky Blue, Indanthrene Blue BC, and the like.
Examples of red colorants include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, resol red, pyrazolone red, watching red, calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, Alizarin Lake, Brilliant Carmine 3B, C.I. I. Pigment Red 2 etc.

Yellow colorants include chrome yellow, zinc yellow, cadmium yellow, yellow iron oxide, mineral first yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake, C.I. I. Pigment Yellow 12 etc.
Examples of green colorants include chrome green, chromium oxide, pigment green B, C.I. I. Pigment Green 7, Malachite Green Lake, Final Yellow Green G, etc.
Examples of the orange colorant include red chrome yellow, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK, C.I. I. Pigment Orange 31 etc.
Examples of purple colorants include manganese purple, first violet B, and methyl violet lake.
Examples of white colorants include zinc white, titanium oxide, antimony white, and zinc sulfide.

  Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white. Examples of various dyes such as basic, acidic, disperse, and direct dyes include nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue.

Examples of inorganic additives include titanium oxide, zinc white, zinc sulfide, antimony oxide, calcium carbonate, lead white, talc, silica, calcium silicate, alumina white, cadmium yellow, cadmium red, cadmium orange, titanium yellow, Examples include bitumen, ultramarine blue, cobalt blue, cobalt green, cobalt violet, iron oxide, carbon black, manganese ferrite black, cobalt ferrite black, copper powder, and aluminum powder.
These pigments and inorganic additives can be used alone or in combination. Of these, carbon black is particularly preferable as the black pigment, and titanium oxide is preferable as the white pigment.
The above colorant can be blended to produce display medium particles having a desired color.

  The particles for display medium of the present invention (hereinafter also referred to as “particles”) have an average particle diameter d (0.5) in the range of 0.1 to 20 μm and are preferably uniform. If the average particle diameter d (0.5) is larger than this range, the display is not clear. If the average particle diameter d (0.5) is smaller than this range, the cohesive force between the particles becomes too large, which hinders movement as a display medium.

  Furthermore, regarding the correlation between the particles for each display medium, the ratio of d (0.5) of the particles having the minimum diameter to d (0.5) of the particles having the maximum diameter among the used particles is 50 or less, preferably 10 or less. It is important to do. Even if the particle size distribution Span is reduced, particles with different charging characteristics move in opposite directions, so that the particle size is close to each other and each particle can be easily moved in the opposite direction by the equivalent amount. This is within this range.

The particle size distribution and the particle size can be obtained from a laser diffraction / scattering method or the like. When laser light is irradiated onto particles to be measured, a light intensity distribution pattern of diffracted / scattered light is spatially generated, and this light intensity pattern has a corresponding relationship with the particle diameter, so that the particle diameter and particle diameter distribution can be measured. .
Here, the particle size and particle size distribution in the present invention are obtained from a volume-based distribution. Specifically, using a Mastersizer2000 (Malvern Instruments Ltd.) measuring instrument, particles are introduced into a nitrogen stream, and the attached analysis software (software based on volume-based distribution using Mie theory) The diameter and particle size distribution can be measured.

  The charge amount of the display medium particles naturally depends on the measurement conditions, but the charge amount of the display medium particles in the information display panel is almost the same as the initial charge amount, the contact with the partition walls, the contact with the substrate, and the elapsed time. It was found that depending on the charge decay, the saturation value of the charging behavior of the particles for the display medium is a dominant factor.

Furthermore, in the information display panel according to the present invention in which the display medium composed of the display medium particles is driven in the gas space, it is important to manage the gas in the void surrounding the display medium between the substrates, and to improve the display stability. Contribute. Specifically, it is important that the relative humidity at 25 ° C. is 60% RH or less, and preferably 50% RH or less for the humidity of the gas in the gap.
1A, 1B, 3B, 3B, and 3B, the gaps are defined as electrodes 5 and 6 (electrodes on the inner side of the substrate). 2), the occupied portion of the display medium 3, the occupied portion of the partition wall 4 (when the partition wall is provided), and the gas portion in contact with the so-called display medium, excluding the seal portion of the information display panel.
The gas in the gap is not limited as long as it is in the humidity region described above, but dry air, dry nitrogen, dry argon, dry helium, dry carbon dioxide, dry methane, and the like are preferable. This gas needs to be sealed in an information display panel so that the humidity is maintained, for example, filling a display medium, assembling an information display panel, etc. in a predetermined humidity environment, It is important to apply a sealing material and a sealing method that prevent moisture from entering from the outside.

The distance between the substrates in the information display panel that is the subject of the present invention is not limited as long as the display medium can be moved and the contrast can be maintained, but is usually adjusted to 10 to 500 μm, preferably 10 to 200 μm.
The volume occupation ratio of the display medium in the gas space between the opposing substrates is preferably 5 to 70%, more preferably 5 to 60%. When it exceeds 70%, the movement as a display medium is hindered, and when it is less than 5%, the contrast tends to be unclear.

  A charge amount retention evaluation sample as an example and a comparative example of the present invention was prepared, and the charge retention property of the manufactured charge amount retention evaluation sample was evaluated.

<Preparation of charge amount retention evaluation sample particles (particles for display medium)>
First, the volume specific resistance is controlled by a method of changing the water absorption of the polymerized resin by combining a monomer having a high polarity and a monomer having a low polarity, and shown in Table 1 below as A1 to A6. Display medium particles having resistance were prepared as sample particles. The average particle diameter d (50) of the obtained particles A1 to A6 was in the range of 9 to 10 μm.
In addition, display medium particles having different volume specific resistances as B1 and B2 shown in Table 1 below were prepared as sample particles by a method of pulverizing a hydrophobic polymer resin material. The average particle diameter d (50) of the obtained particles B1 and B2 was in the range of 9 to 10 μm.

  In Table 1 below, A: Kyoeisha Chemical Co., Ltd. light ester TB (tert-butyl methacrylate), B: Light ester IB (isobutyl methacrylate) was used as the low polarity monomer. As the highly polar monomer, A: light acrylate MTG-A (methoxypolyethylene glycol acrylate) and B: light acrylate 3EG-A (triethylene glycol diacrylate) manufactured by Kyoeisha Chemical Co., Ltd. were used. As an initiator, V65 manufactured by Wako Pure Chemical Industries, Ltd. was used. Toyostyrene E640N manufactured by Toyo Styrene Co., Ltd. was used as the styrene = butadiene copolymer resin. As the cycloolefin resin, ZEONEX-330R manufactured by Nippon Zeon Co., Ltd. was used.

  The volume resistivity of the resin constituting the particles for the display medium is prepared by depositing gold (Au) on the upper and lower surfaces of a sheet-like volume resistance measurement sample (50 mm □ × 0.50 mmt), and a measuring device (ADVANTEST R8340A + TR42) Was used to measure the resistance value when a 500 V bias voltage was applied. The measurement environment was temperature: 23 ± 0.5 ° C. and humidity: 50 ± 5 rh%.

<Evaluation of sample charge retention>
Each of the display medium particles deposited on the aluminum flat plate at a density of 0.5 g / cm ² was charged with 20 μC / g by applying a corona discharge generated by applying 1 kV. Thereafter, an aluminum flat plate was grounded and left standing. The charge amount of the particles was measured 15 days and 30 days after charging. The charge decay rate was calculated from the charge amount decay up to 30 days. The standing and charge amount measurement were carried out in an environment of temperature: 23 ± 0.5 ° C. and humidity: 50 ± 5 rh%. The results are shown in Table 2 below. At the same time, FIG. 5 shows the relationship between the number of days left for each sample obtained from the results in Table 2 and the charge amount. The charge amount was measured with a suction type charge amount measuring device 210HS manufactured by Trek.

From the results of Table 2 and FIG. 5, A3 to A6, A9 to A12, and B1 and B2 having a volume resistivity of 1 × 10 ¹⁴ Ω · cm or more are A1 having a volume resistivity of less than 1 × 10 ¹⁴ Ω · cm, Compared to A2, A7, and A8, it can be seen that better charge amount retention characteristics can be obtained.

<Image density of sample particles for display medium>
In the above charge retention characteristics samples A1 to A6, carbon black (Mitsubishi Chemical: Carbon-Black # 3030B) as a black pigment is mixed in 5.0 parts by weight, and the charge control agent (Orient Chemical: Bontron N07) is in parts by weight. 0.5 part of the mixture was added, and positively charged silica fine particles (Wacker (Germany) H3050) were externally attached to the surface of the 5.0 parts by weight of the particles to prepare positively charged particles. On the other hand, B1 and B2 contain 100 parts by weight of titanium oxide (Ishihara Sangyo Co., Ltd .: CR-90) as a white pigment, and 0.5 parts by weight of negatively chargeable charge control agent (Orient Chemical Co., Ltd .: E88). Further, negatively chargeable silica fine particles (Wacker (Germany) H3004) were externally attached to the particle surface of 5.0 parts by weight to prepare negatively chargeable particles.

  An image is displayed using the information display panel for evaluation in which the black particles A1 to A6 and the white particles B1 and B2 are combined and enclosed, and the image is again displayed after the evaluation solid image is displayed. The display was switched and the change in image density was evaluated. The evaluation panel used was provided with partition walls arranged in a rectangular cell grid of 300 μm square in FIG. 4 and the distance between the upper and lower substrate electrodes was 40 μm. White and black solid images are displayed by alternately applying a DC voltage of 100 V between the electrodes of the panel. The image density was evaluated by black density measurement with an absolute white standard using a RD-19 optical densitometer manufactured by Gretag Macbeth (Switzerland). In this evaluation, the density difference between black display and white display is used as an evaluation value, and this value is passed when it is left for 30 days, and it is rejected at other times. The results are shown in Table 3 below.

From Table 3, the volume specific resistance of the resin material of the display medium particles is set to 1.00 × 10 ¹⁴ Ω · It turned out that it is necessary to make it more than cm.

  The information display panel according to the present invention includes a notebook computer, an electronic notebook, a portable information device called PDA (Personal Digital Assistants), a display unit of a mobile device such as a mobile phone and a handy terminal, an electronic paper such as an electronic book and an electronic newspaper. , Billboards such as signboards, posters, blackboards (whiteboards), electronic desk calculators, display units for home appliances, automotive products, card display units such as point cards, IC cards, electronic advertisements, information boards, electronic POPs (Point Of) Presence, Point Of Purchase advertising), electronic price tag, electronic shelf label, electronic score, display unit of RF-ID device, as well as display unit of various electronic devices such as POS terminal, car navigation device, clock.

  As for the information display panel according to the present invention, a simple matrix drive display panel or static drive display panel that does not use a switching element in the panel itself, or a three-terminal switching element represented by a thin film transistor (TFT). Alternatively, it can be used as an information display panel of various types of drive systems, such as an active matrix drive display panel using a two-terminal switching element represented by a thin film diode (TFD).

(A), (b) is a figure which shows an example of the information display panel of this invention, respectively. (A), (b) is a figure which shows the other example of the information display panel of this invention, respectively. (A), (b) is a figure which shows the further another example of the information display panel of this invention, respectively. It is a figure which shows an example of the shape of the partition in the information display panel of this invention. It is a graph which shows the relationship between the leaving days of each sample in an Example, and the charge amount.

Explanation of symbols

1, 2 Substrate 3 Display medium (particle group)
3W White display medium 3Wa White display medium particles 3B Black display medium 3Ba Black display medium particles 4 Bulkhead 5, 6 Electrode

Claims (3)

A display medium used for an information display panel that displays information such as an image by moving the display medium by enclosing the display medium between two substrates transparent at least one and applying an electric field to the display medium A particle for a display medium, wherein the volume specific resistance of a resin constituting the particle is 1 × 10 ¹⁴ Ω · cm or more.   2. The display medium particle according to claim 1, wherein the particle charge decay rate is 0.3 μC / g · day or less when left for 30 days after being initially charged to 20 μC / g.   An information display panel for displaying information such as an image by moving a display medium by enclosing a display medium between two substrates transparent at least one and applying an electric field to the display medium. 2. An information display panel, wherein the display medium particle according to 2 is used as a display medium.

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