JP4863644B2 - Manufacturing method of information display panel - Google Patents

Description

  The present invention provides at least one or more kinds of optical reflectance and chargeability composed of at least one kind of particles in a cell formed by a partition between two opposing substrates, at least one of which is transparent. The present invention relates to a method for manufacturing an information display panel that encloses a display medium and applies an electric field to the display medium to move the display medium to display information such as an image.

  2. Description of the Related Art Conventionally, information display devices using techniques such as electrophoresis, electrochromic, thermal, and two-color particle rotation have been proposed as information display devices that replace liquid crystal (LCD).

  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 colored 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. Furthermore, since particles with high specific gravity such as titanium oxide are dispersed in a solution with low specific gravity, it is easy to settle, it is difficult to maintain the stability of the dispersed state, and the stability of repeated rewriting of information display is lacking. Have 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.

  On the other hand, a method in which conductive particles and a charge transport layer are incorporated into a part of a substrate without using a solution is proposed instead of an electrophoresis method using behavior in a solution (see, for example, Non-Patent Document 1). ). However, the structure is complicated because the charge transport layer and further the charge generation layer are arranged, and it is difficult to uniformly inject the charge into the conductive particles.

As a method for solving the various problems described above, an optical reflectance composed of at least one kind of particles in a cell formed by a partition between two opposing substrates, at least one of which is transparent. In addition, an information display panel that displays information such as an image by moving the display medium by enclosing at least one display medium having charging properties and applying an electric field to the display medium is known.
趙 Kuniori and three others, “New Toner Display Device (I)”, July 21, 1999, Annual Meeting of the Imaging Society of Japan (83 times in total) “Japan Hardcopy'99” Proceedings, p.249-252

  In the method for manufacturing an information display panel described above, as a method for enclosing a display medium (in other words, display medium particles constituting the display medium) between substrates, charged colored particles for display medium are filled with particles. There has been an attempt to fill the colored particles for the display medium by applying a potential opposite to the particles to the back side of the substrate so that the charged particles are guided into the cell.

  However, the charged particles are placed on a charging medium such as a photoconductor, and a charged electrode is introduced into the cell by applying a potential opposite to the particles to the back side of the substrate to be filled with the particles. In an attempt to fill the display medium with colored particles, some of the charged particles on the charging medium do not fly and move to the substrate cell side while remaining on the charging medium. There was a problem that a cell that was not filled was formed. The above problem is likely to occur when the height of the partition walls forming the cell is high. In the panel manufacturing in which the height of the partition wall exceeds 30 μm, the display medium (particles) cannot be filled in the cell by this method. It was.

  An object of the present invention is to solve the above-described problems and to provide a method for manufacturing an information display panel capable of reliably filling a display medium without generating cells that are not filled with the display medium. .

The method for producing an information display panel according to the present invention comprises an optical reflectance and charging comprising at least one kind of particles in a cell formed by a partition between two opposing substrates, at least one of which is transparent. In a method of manufacturing an information display panel for enclosing at least one type of display medium having a property and applying an electric field to the display medium to display information such as images by moving the display medium, In addition, a mixture of a display medium charged with one polarity and a display medium having a charge amount larger than that of the display medium is arranged, and a potential of the other polarity opposite to the display medium is applied from the back side of the substrate. giving the display medium is characterized in the Turkey be filled in the cell.

  As a preferred example of the method for producing the information display panel of the present invention, a display medium (particles for display medium) in which the mixing amount of a display medium (display medium particles) having a large charge amount has the predetermined charge amount. On the other hand, it may be 3 to 30%, and the display medium may be a particle group or a powder fluid.

  According to the method for manufacturing an information display panel of the present invention, when a display medium is filled, first, particles having large charge amount that are easy to fly start to fly and have a polarity opposite to that of the display medium given to the back side of the substrate. In addition to being guided into the cell by this potential, other slightly charged particles also fly together, so that the display medium can be surely filled without producing cells that are not filled with the display medium.

  First, the basic structure of the information display panel manufactured according to the manufacturing method 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 opposing substrates. Along with the applied electric field direction, the charged display medium is attracted by the electric field force or Coulomb force, etc., and the display medium changes the moving direction by changing the electric field direction by switching the potential, thereby displaying information such as an image. Is made. Therefore, it is necessary to design the information display panel so that the display medium can move uniformly and maintain the rewrite stability of display information or the continuous display stability of display information. Here, as the force applied to the particles constituting the display medium, in addition to the force attracted by the Coulomb force between the particles, an electric image force with the electrode, an intermolecular force, a liquid cross-linking force, gravity and the like can be considered.

  An example of an information display panel manufactured according to the manufacturing method 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 types of display media 3 (here, white display consisting of a group of particles) having at least one type of particles and different optical reflectance and charging characteristics. The substrate 1 corresponds to an electric field generated by applying a voltage between the electrode 5 provided on the substrate 1 and the electrode 6 provided on the substrate 2. 2, the black display medium 3 </ b> B is visually recognized by the observer and black display is performed, or the white display medium 3 </ b> W is visually recognized by the observer and white display is performed. In the example shown in FIG. 1B, the partition walls 4 are formed between the substrates 1 and 2, and a plurality of rectangular cells are provided in a lattice shape. (The partition in front of the figure is omitted.)

  In the example shown in FIGS. 2A and 2B, a display medium 3 (here, a white display medium consisting of a group of particles) having at least one type of optical reflectance and chargeability composed of at least one type of particles. 3W) is moved in parallel with the substrates 1 and 2 according to the electric field generated by applying a voltage between the electrode 5 and the electrode 6 provided on the substrate 1, and the white display medium 3W is moved to the observer. The color of the electrode 6 or the substrate 1 (color expressed by an optical reflectivity different from that of the white display medium 3W) is displayed by making the viewer visually recognize the electrode 6 or the substrate 1 Is displayed. In the example shown in FIG. 2B, a partition wall 4 is formed between the substrates 1 and 2, and a plurality of quadrangular cells are provided in a lattice shape. (The partition in front of the figure is omitted.)

  In the example shown in FIGS. 3A and 3B, a display medium 3 (here, a white display medium consisting of a group of particles) having one kind of optical reflectance and chargeability composed of at least one kind of particles. 3W) is moved in parallel with the substrates 1 and 2 according to the electric field generated by applying a voltage between the electrode 5 and the electrode 6 provided on the substrate 1, and the white display medium 3W is moved to the observer. The color of the electrode 6 or the substrate 1 (color expressed by an optical reflectivity different from that of the white display medium 3W) is displayed by making the viewer visually recognize the electrode 6 or the substrate 1 Is displayed. In the example shown in FIG. 3B, a partition wall 4 is formed between the substrates 1 and 2, and a plurality of quadrangular cells are provided in a lattice shape. (The partition in front of the figure is omitted.)

  The above description is similarly applied to the case where the white display medium 3W including the particle group is replaced with the white display medium including the powder fluid and the black display medium 3B including the particle group is replaced with the black display medium including the powder fluid. I can do it.

  In manufacturing the information display panel having the above-described configuration, the present invention is characterized in that a display medium charged with one polarity is disposed on a cell of a substrate, and the other polarity having the opposite polarity to the display medium from the back side of the substrate. A display medium having a charge amount larger than that of a display medium (particles for display medium) having a predetermined charge amount as a display medium to be filled and filled with the display medium in a cell by applying a polar potential It is in using what mixed (particles for display media).

  Further, the mixing amount of the display medium having a large charge amount is not particularly limited, but the mixing amount of the display medium having a large charge amount is preferably 3 to 30% with respect to the display medium having a predetermined charge amount. Here, if the mixing amount is less than 3%, the effect of mixing a display medium having a large charge amount cannot be sufficiently obtained. If the mixing amount exceeds 30%, the main display medium has a charge amount of It is not clear whether the display medium is a small display medium or a display medium with a large charge amount, and the effect of filling the display medium according to the present invention cannot be sufficiently obtained.

  4 and 5 are diagrams for explaining the mixing amount in the information display panel of the present invention. In the example shown in FIGS. 4 and 5, display medium particles 3-1 with a large charge amount in the center of the display medium (3 </ b> B or 3 W) are particles 3-2 with a slightly small charge amount around them. Think about the impact on In the filled state shown in FIG. 4, assuming that 8 to 24 display medium particles 3-2 around one display medium particle 3-1 are affected, the ratio of the mixing amount is 4 to 13. %. On the other hand, in the filled state shown in FIG. 5, assuming that 6 to 18 display medium particles 3-2 around one display medium particle 3-1 are affected, the ratio of the mixing amount is 6. ~ 17%. In the present invention, the mixing amount thus determined is preferably in the range of 3 to 30%.

  FIG. 6 is a diagram for explaining an example of a method for manufacturing an information display panel according to the present invention. In the example shown in FIG. 6, first, the display medium 3 (here, the white display medium 3 </ b> W) is supplied from the display medium supply device 11 to the display medium support roller 12 (display medium supply support process). At this time, in the present invention, the white display medium 3W to be filled is a mixture of a white display medium having a predetermined charge amount and a white display medium (white display medium particles) having a charge amount larger than the charge amount. Is used.

  Next, the surface of the display medium supply drum 15 is charged by the charging device 13, and the display medium carrying roller 12 is rotated and supplied to the display medium carrying roller 12 on the surface of the display medium supply drum 15. Thus, the display medium 3 in which display medium particles having a larger charge amount are mixed with a display medium having a predetermined charge amount at a predetermined ratio is placed on the display medium supply drum 15 in an array.

  A conveyance belt 16 that conveys the panel substrate 1 runs under the display medium supply drum 15, and is arranged on the display medium supply drum 15 on the back side of the conveyance belt 16 facing the display medium supply drum 15. A transfer device 17 for transferring the display medium 3 to the substrate 1 is provided. When the substrate 1 conveyed by the conveyance belt 16 passes between the display medium supply drum 15 and the transfer device 17, the display medium 3 arranged and placed on the display medium supply drum 15 is replaced with the panel substrate 1 (or 2) While being transferred and filled in the upper cell 14, the highly charged particles that are likely to fly first start to fly, and the entire display medium flies so as to be pulled (display medium transfer filling step).

  As described above, an information display panel is obtained by bonding the other substrate 2 (or 1) to the substrate 1 (or 2) in which the predetermined display medium 3 is filled in the cell 14. (Panel bonding process).

  7 and 8 are diagrams for explaining another example of the method for manufacturing the information display panel according to the present invention. In the examples shown in FIGS. 7 and 8, the same members as those in the example shown in FIG. In the example shown in FIG. 7, in order to supply the charged display medium 3 to the display medium supply drum 15, a display medium dispersion supply device 23 including a nozzle 21 and a container 22 and a display medium carrying belt 24 are used. In the example shown in FIG. 8, the display medium supply device 11 and the display medium carrying belt 24 are used to supply the charged display medium 3 to the display medium supply drum 15. In any case, the display medium 3 used here is a white display medium 3W in which a white display medium having a predetermined charge amount is mixed with particles for a white display medium having a charge amount larger than the charge amount. The same effect as the above-described example can be obtained.

  Hereinafter, each member which comprises the information display panel used as the object 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, polyethersulfone, polyethylene, polycarbonate, polyimide, and acrylic, flexible materials such as metal sheets, and flexible materials such as glass and quartz. There are no inorganic sheets. 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.

  Electrode forming materials for providing electrodes on information display panels include metals such as aluminum, silver, nickel, copper, and gold, and conductive metal oxides such as ITO, indium oxide, conductive tin oxide, and conductive zinc oxide. , Conductive polymers such as polyaniline, polypyrrole, and polythiophene are exemplified and appropriately selected and used. As a method for forming an electrode, a method of forming the above-described materials into a thin film by sputtering, vacuum deposition, CVD (chemical vapor deposition), coating, or the like, or mixing a conductive agent with a solvent or a synthetic resin binder. The method of apply | coating 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. Note that the electrode thickness is not particularly limited as long as the conductivity can be secured and the light transmittance is not hindered, and is preferably 3 to 1000 nm, preferably 5 to 400 nm. 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 height and width of the partition provided on the substrate are appropriately set according to the type of display medium involved in display, and are not generally limited. However, the partition width is 2 to 100 μm, preferably 3 to 50 μm, and the height of the partition is 10 It is adjusted to ˜500 μm, preferably 10 to 200 μm. The cell shape in the information display panel obtained by superimposing the display side substrate and the back side substrate may be various shapes as illustrated in FIG. 9 depending on the partition wall shape. It is better to make the portion corresponding to the partition cross section visible from the display surface side (the area of the cell frame formed by the partition width) as small as possible, and the display state becomes clearer.

  Next, the powder fluid used as a display medium in the information display panel of the present invention will be described. As for the name of the powder fluid used in the information display panel of the present invention, the present applicant has obtained the right of “Electronic Powder Fluid (registered trademark): Registration No. 4636931”.

  The “powder fluid” in the present invention is a substance in an intermediate state of both fluid and particle characteristics that exhibits fluidity by itself without borrowing the force of gas or liquid. For example, liquid crystal is defined as an intermediate phase between a liquid and a solid, and has fluidity that is a characteristic of liquid and anisotropy (optical properties) that is a characteristic of solid (Heibonsha: Encyclopedia) . On the other hand, the definition of particle is an object with a finite mass even if it is negligible, and is said to be affected by gravity (Maruzen: Physics Encyclopedia). Here, even in the case of particles, there are special states of gas-solid fluidized bed and liquid-solid fluids. When gas is flowed from the bottom plate to the particles, upward force is applied to the particles according to the velocity of the gas. Is a gas-solid fluidized bed that is in a state where it can easily flow when it balances with gravity, and it is also called a liquid-solid fluidized state that is fluidized by a fluid (ordinary) Company: Encyclopedia). As described above, the gas-solid fluidized bed body and the liquid-solid fluid are in a state of using a gas or liquid flow. In the present invention, it has been found that a substance in a state of fluidity can be produced specifically without borrowing the force of such gas and liquid, and this is defined as powder fluid.

  That is, the pulverulent fluid in the present invention is in an intermediate state having both the characteristics of particles and liquid, as in the definition of liquid crystal (liquid and solid intermediate phase), and is the characteristic of the above-mentioned particles. It is a substance that is extremely unaffected and exhibits a unique state with high fluidity. Such a substance can be obtained in an aerosol state, that is, in a dispersion system in which a solid or liquid substance is stably suspended as a dispersoid in a gas, and the solid substance is regarded as a dispersoid in the information display panel of the present invention. To do.

The information display panel of the present invention encloses a powder fluid exhibiting high fluidity in an aerosol state in which solid particles are stably suspended as a dispersoid, for example, in a gas between opposing substrates, at least one of which is transparent. Yes, such a powder fluid can be easily and stably moved by a Coulomb force or the like by applying a low voltage.
As described above, for example, the powder fluid used as the display medium in the present invention is a substance in the intermediate state between the fluid and particles that exhibits fluidity by itself without borrowing the force of gas or liquid. It is. This powder fluid can be in an aerosol state in particular, and in the information display panel of the present invention, it is used as a display medium in a state where a solid substance floats relatively stably as a dispersoid in the gas.

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 composed of the display medium particles as they are to form a display medium, or are combined with other particles to form a display medium, or adjusted and configured to become a powder fluid to form a display medium. Or used.
The 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. 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.

As yellow colorants, yellow lead, 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 yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, Indanthrene Brilliant Orange RK, Benzidine Orange G, Indanthren 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.

As extender pigments, barite powder, barium carbonate, clay, silica, white carbon,
There are 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.

  Further, the particles of the present invention preferably have an average particle diameter d (0.5) in the range of 0.1 to 20 μm, and are uniform and uniform. If the average particle diameter d (0.5) is larger than this range, the display is not clear, and if it is smaller than this range, the cohesive force between the particles becomes too large, which hinders the movement of the particles.

Furthermore, in the present invention, regarding the particle size distribution of each particle, the particle size distribution Span represented by the following formula is less than 5, preferably less than 3.
Span = (d (0.9) −d (0.1)) / d (0.5)
(However, d (0.5) is a numerical value expressing the particle diameter in μm that 50% of the particles are larger than this and 50% is smaller than this, and d (0.1) is a particle in which the ratio of the smaller particles is 10%. (Numerical value expressed in μm, and d (0.9) is a numerical value expressed in μm for a particle diameter of 90% or less.)
By keeping Span within a range of 5 or less, the size of each particle is uniform, and the display medium can be moved uniformly.

  Furthermore, regarding the correlation between the particles, 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 set to 50 or less, preferably 10 or less. It is essential. 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.

  As a result of intensive studies, the inventors of the present invention have been able to evaluate the range of proper charging characteristics of display medium particles by measuring the charge amount of display medium particles using the same carrier particles in the blow-off method. I found it.

Furthermore, when the present invention is used for a dry information display panel, it is important to manage the gas in the gap surrounding the display medium, which contributes to improved display stability. Specifically, it is important that the relative humidity at 25 ° C. is 60% RH or less, preferably 50% RH or less, more preferably 35% RH or less with respect to the humidity of the gas in the gap.
1A, 1B, 3A, and 3B, the gaps are defined by the electrodes 5 and 6 (the electrodes are placed on the inside of the substrate). Gas portion in contact with the so-called display medium, excluding the occupied portion of the display medium 3 (particle group or powdered fluid), the occupied portion of the partition wall 4 (when the partition wall is provided), and the seal portion of the information display panel. Shall be pointed to.
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 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.
In the case of a dry information display panel, the volume occupancy of the display medium in the space between the opposing substrates is preferably 5 to 70%, more preferably 5 to 60%. When it exceeds 70%, the movement of the display medium is hindered, and when it is less than 5%, the contrast tends to be unclear.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples and comparative examples of the present invention, but the present invention is not limited to the following.

"Preparation of display media"
In Examples and Comparative Examples, the display medium used was prepared by mixing and mixing particle groups (particle group A and particle group B) composed of white display medium particles having the following two types of chargeability.

Particle group A was prepared by dissolving 0.5 parts by weight of AIBN (azobisisobutyronitrile) in 80 parts by weight of tertiary butyl methacrylate monomer and 20 parts by weight of 2- (diethylamino) ethyl methacrylate. The liquid obtained by dispersing 20 parts by weight of titanium oxide made lipophilic by treatment with an agent is suspended and polymerized in an aqueous solution of 0.5% surfactant (sodium lauryl sulfate), filtered, dried. Then, it was prepared using a classifier (MDS-2: Nippon Numatic Industries). The produced particle group A was a positively charged spherical white particle group having an average particle diameter of 8.5 μm and a charge amount of +10 μC / g.
Particle group B was prepared in the same manner as particle group A except that 2 parts by weight of charge control agent Bontron N07 (manufactured by Orient Chemical Co., Ltd.) was added to particle group A. The produced particle group B was a positively chargeable spherical white particle group having an average particle diameter of 8.2 μm and a charge amount of +17 μC / g.

"Production of panel substrate"
A glass transparent substrate with ITO electrodes (7 cm × 7 cm □) was prepared, ribs having a height of 50 μm were formed on one substrate, and square-shaped and grid-shaped partition walls were formed.
The partition wall was formed as follows. A dry film photoresist NIT250 made by Nichigo Morton, which is a photosensitive film, was laminated on a glass with ITO, and a partition wall having desired lines of 30 μm, spaces of 320 μm, and pitch of 350 μm was formed by exposure and development. As the other substrate, a glass transparent substrate (7 cm × 7 cm □) with an ITO electrode was prepared.

<Example 1>
A white display medium in which a small amount of the particle group B is mixed with the particle group A (the mixing ratio of the particle group B is 3% by weight) is prepared, and the partition wall is formed by the display medium filling step shown in FIG. The cells of the substrate were continuously filled. The filling arrangement amount was adjusted so that the volume occupation ratio between the substrates formed by bonding the two substrates was 25 vol%.

<Example 2>
The display medium was filled in the same procedure as in Example 1 except that a white display medium in which a small amount of the particle group B was mixed with the particle group A (the mixing ratio of the particle group B was 30% by weight) was prepared.

<Example 3>
The display medium was filled in the same procedure as in Example 1 except that a white display medium in which a small amount of the particle group B was mixed with the particle group A (the mixing ratio of the particle group B was 10% by weight) was prepared.

<Example 4>
The display medium was filled in the same procedure as in Example 1 except that a white display medium in which a small amount of the particle group B was mixed with the particle group A (the mixing ratio of the particle group B was 20 wt%) was prepared.

<Comparative Example 1>
The display medium was filled in the same procedure as in Example 1 except that a white display medium in which a large amount of the particle group B was mixed with the particle group A (the mixing ratio of the particle group B was 40% by weight) was prepared.

<Comparative example 2>
The display medium was filled in the same procedure as in Example 1 except that a white display medium in which a small amount of the particle group B was mixed with the particle group A (the mixing ratio of the particle group B was 1 wt%) was prepared.

  The results are shown in Table 1.

  From the results in Table 1, in Examples 1 to 4 using the display medium in which the mixing ratio of the highly charged display medium particles in the display medium is in the range of 3 to 30% by weight, a predetermined amount to be filled in the cell on the substrate In Comparative Examples 1 and 2 using a display medium in which the mixing ratio of the highly charged display medium particles in the display medium is not in the range of 3 to 30% by weight, the display medium can be filled into the cell on the substrate. It was found that the display medium could not be filled with high accuracy, and an unfilled cell was formed.

  Information display panels subject to the manufacturing method of the present invention include display units of mobile devices such as notebook computers, PDAs, mobile phones, and handy terminals, electronic papers such as electronic books and electronic newspapers, signboards, posters, and blackboards. For bulletin boards, calculators, home appliances, automobile supplies, etc., card displays such as point cards, IC cards, electronic advertisements, electronic POPs, electronic shelf labels, electronic price tags, electronic musical scores, RF-ID device displays, etc. Preferably used.

(A), (b) is a figure which shows the structure of an example of the information display panel used as the object of the manufacturing method of this invention, respectively. (A), (b) is a figure which shows the structure of the other example of the information display panel used as the object of the manufacturing method of this invention, respectively. (A), (b) is a figure which shows the structure of the further another example of the information display panel used as the object of the manufacturing method of this invention, respectively. It is a figure for demonstrating an example of the mixing amount in the manufacturing method of the information display panel of this invention. It is a figure for demonstrating the other example of the mixing amount in the manufacturing method of the information display panel of this invention. It is a figure for demonstrating an example of the manufacturing method of the information display panel of this invention. It is a figure for demonstrating the other example of the manufacturing method of the information display panel of this invention. It is a figure for demonstrating the further another example of the manufacturing method of the information display panel of this invention. It is a figure which shows an example of the shape of the partition in the information display panel used as the object of the manufacturing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Substrate 3 Display medium 3W White display medium 3B Black display medium 4 Bulkhead 5, 6 Electrode 11 Display medium supply device 12 Display medium carrying roller 13 Charging device 14 Cell 15 Display medium supply drum 16 Conveying belt 17 Transfer device 21 Nozzle 22 Container 23 Display medium dispersion supply device 24 Display medium carrying belt

Claims (3)

At least one type of display medium having optical reflectivity and chargeability composed of at least one type of particles is enclosed in a cell formed by a partition between two opposing substrates, at least one of which is transparent. and, by applying an electric field to the display media, in the production method of the information display panel by moving the display media to display information such as an image, on a cell substrate, a display medium Toko charged to one polarity place a mixture of a display medium having a larger charge amount than the display medium, the display medium from the backside of the substrate to fill the display media by applying the other polarity of the potential is opposite polarity to the cell Turkey A method for producing an information display panel characterized by:   2. The method for manufacturing an information display panel according to claim 1, wherein a mixing amount of the display medium having a large charge amount is 3 to 30% with respect to the display medium having the predetermined charge amount.   The method for manufacturing an information display panel according to claim 1, wherein the display medium is a particle group or a powder fluid.

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