JP4587682B2 - Manufacturing method of image display panel - Google Patents

Description

  In the present invention, at least one of the substrates is a transparent opposing substrate, and at least one of the substrates is formed by stacking two substrates on the surface of which partition walls defining display cells are formed, and a particle group or The present invention relates to a method for manufacturing an image display panel having a structure for sealing a powder fluid.

  2. Description of the Related Art Conventionally, image display devices using techniques such as an electrophoresis method, an electrochromic method, a thermal method, and a two-color particle rotation method have been proposed as image display devices that can 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 image 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, and it is difficult to maintain the stability of the dispersed state, and there is a problem of lack of image repetition stability. . 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 inject the charges into the conductive particles.

As a method for solving the various problems described above, a cell isolated from each other by a partition is formed between a front substrate and a rear substrate, and a particle group or a powder fluid is enclosed in the cell. 2. Description of the Related Art An image display device including an image display panel that displays an image by applying an electric field to a fluid and moving particles or powdered fluid by Coulomb force or the like 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 above-described image display device, usually, at least one of the substrates is a transparent opposing substrate, and at least one of the substrates is formed by superimposing two substrates on which a partition wall defining a display cell is formed, In the meantime, an image display panel having a structure in which a particle group or powder fluid is sealed is used. In this image display panel, a process of filling a particle group or a powder fluid into a display cell defined by partition walls is important. Conventionally, a device similar to a dry LCD spacer spraying device has been used in the particle group or powder fluid filling step.

  In the image display panel and liquid crystal panel using the particle group or powdered fluid that are the subject of the present invention, the amount of charging of the particle group or powdered fluid and the charging characteristics vary greatly. If it is used as it is, problems such as a slow filling speed and a non-uniform filling amount of particle groups and the like have occurred. As described above, when the filling amount is not uniform in each display cell of the panel, there is a problem that unevenness occurs in the display of the image display panel.

  An object of the present invention is to solve the above-described problems, and to provide a method for manufacturing an image display panel that has a high filling speed and a uniform amount of particles or powder fluid, and as a result, has no image display unevenness. To do.

The method for producing an image display panel according to the present invention comprises two substrates, at least one of which is a transparent opposing substrate, on which at least one substrate is formed with a partition wall defining a display cell. In the method of manufacturing an image display panel having a structure in which particle groups or powdered fluid is sealed between the two, the absolute value of the charge amount of the particle groups or powdered fluid when the particle groups or powdered fluid is dispersed in the display cell. The powder supply box having a gas injection port and a gas discharge port connected to the powder ejection nozzle is filled with particles or powder fluid so as to be 5 (μC / g) or more . the by keeping a positive pressure, by spraying the particles or liquid powders, which consisted powder ejection nozzle and a floating state, to fill the required amount of the particles or the liquid powders and in the display cells on the board It is a feature.

Further, as a preferable embodiment of the production method of the image display panel of the present invention is to the absolute value of the charge amount of the particles or the liquid powders and 100 (μC / g) or less, 1 from the powder feed box (g / min) Disperse the particle group or powder fluid at a speed of at least, and the pipe connecting the powder supply box and the powder ejection nozzle is 500 mm or more, and connect the powder supply box and the powder ejection nozzle The value obtained by dividing the inner wall length of the cross-section of the thinnest portion by the inner cross-sectional area among the pipes connecting the powder supply box and the powder jet nozzle is 0.66 (mm ^{− 1} ) It is more than that, and the structure of the piping connecting the powder supply box and the powder jet nozzle is divided into a plurality of pipes on the way and joined again.

  According to the present invention, when the particle group or the powder fluid is dispersed in the display cell, the particle group or the powder fluid is added so that the absolute value of the charge amount of the particle group or the powder fluid is 5 (μC / g) or more. By dispersing the particles in the display cells and filling the display cells on the substrate defined by the partition walls with the required amount of particles or powder fluid, the particles or powder fluid is evenly distributed in the display cells between the substrates. Can be filled. Even if the filling speed is increased, uniform filling is possible. As a result, image display unevenness can be eliminated in the image display panel.

  First, a basic configuration of an image display panel that is an object of the present invention will be described. In the image display panel used in the present invention, an electric field is applied to a particle group or powder fluid sealed between two opposing substrates. Along the applied electric field direction, particles or powder fluid charged at a low potential toward the high potential side is attracted by Coulomb force, and particles charged at a high potential toward the low potential side. Alternatively, the powder fluid is attracted by Coulomb force or the like, and the particle group or the powder fluid reciprocates due to the change in the electric field direction due to the potential switching, thereby displaying an image. Therefore, it is necessary to design the image display panel so that the particle group or the powder fluid can move uniformly and maintain the stability at the time of repetition or storage. Here, the force applied to the particles or the powder fluid may be an electric image force with the electrode or the substrate, an intermolecular force, a liquid bridge force, gravity, etc., in addition to the force attracted by the Coulomb force between the particles or the powder fluid. .

  Next, an image display operation in the basic configuration of the above-described image display panel will be described. The image display panel used in the present invention is, for example, by moving particles 3 of two different colors (see FIG. 1; here, white particles 3W and black particles 3B) are moved in a direction perpendicular to the substrates 1 and 2. The present invention can be applied to both a panel used for a display method and a panel using a display method by moving particles 3W of one kind of color (see FIG. 2) in a direction parallel to the substrates 1 and 2. An example of a panel structure for display is shown in FIG. 1 to 3, reference numeral 4 denotes partition walls provided for forming cells, and reference numerals 5 and 6 denote electrodes provided as necessary to give an electric field to the particles 3. The above description can be similarly applied to the case where the white particles 3W are replaced with the white powder fluid and the black particles 3B are replaced with the black powder fluid.

Hereinafter, a method for producing an image display panel, which is a feature of the present invention, will be described in detail.
The manufacturing method of the image display panel of the present invention has been completed by the inventors' efforts to improve the spraying speed of the particle group or the powder fluid. First, the research flow will be described.

  First, the present inventors tried to cope with the problem by increasing the rotation speed of the powder supply feeder in order to improve the spraying speed of the particle group or the powder fluid. Increasing the number of revolutions increased the supply of particles or powdered fluid, enabling the expected amount of spraying. However, in the process of increasing the number of rotations and spraying, the image display panel to be manufactured often suffers from a decrease in contrast and unevenness. It has been found that this is caused by spilling of the particle group or the powder fluid in a step after the filling process of the particle group or the powder fluid. As a result of further investigation, as the spraying speed is increased, the charged amount of the dispersed particles or powdered fluid is significantly reduced, and the adhesion force of the particles or powdered fluid to the substrate is reduced. Thus, it became clear that the bulk of the filled particle group or the powder fluid 51 becomes high and the required amount does not fall below the height of the partition wall 52.

  From these findings, in the manufacture of the image display panel, an appropriate amount of charge is required to appropriately attach the particle group or powder fluid 52 to the substrate 53, and the particle group or powder fluid 52 is applied to the substrate 53. It was found that a technique for maintaining an appropriate charge amount without reducing the filling speed is important. Based on the above-mentioned knowledge, the optimum charge amount which is a feature of the present invention is obtained from the experiment of the charge amount of the particle group or the powder fluid, and as a preferred example, the pipe length dependency of the charge amount of the particle group or the powder fluid, the particle The dependence of the charge amount of the group or powder fluid on the pipe diameter and the dependence of the charge amount on the number of branch pipes were determined. Hereinafter, it demonstrates in order.

<Regarding the charge amount of particles or powder fluid>
Using particle groups or powder fluids having various charge amounts, the particle groups or powder fluids were actually filled in the display cells on the substrate, and it was determined whether or not there was a defect in the uniform example at the time of filling. The results when using the powder fluid 3 are shown in Table 1 below. Similar results were obtained when similar experiments were performed using particle group 3.

  From the results in Table 1, it was found that the charge amount of the particle group or powdered fluid after spraying must be 5 (μC / g) or more. Note that if the charge amount of the particle group or powder fluid is too large, the voltage required to first drive the particle group or powder fluid when the panel is assembled becomes too high, and initialization as an image display panel is difficult. Become. Initialization is a process performed to make the charge amount of the particle group or the powder fluid appropriate, and is first performed after the panel is assembled. Once this process is performed, subsequent driving can be performed smoothly. From that viewpoint, it is preferable to set it to 100 (μC / g) or less. The charge amount (μC / g) is calculated by measuring the charge amount and weight of particles or powder fluid dispersed on the substrate using the “q / m Meter Model 210HS-2A” from TREK. did.

Based on the knowledge about the charge amount of the above particle group or powder fluid, a preferred example of the present invention was determined as follows.
FIG. 4 and FIG. 5 are views showing the configuration of an example of a powder supply apparatus used in a preferred example of the method for manufacturing an image display panel of the present invention. 4 and 5, the powder supply device 11 includes a particle group in a powder supply box 16 including a gas injection port 12 and a gas discharge port 15 connected to the powder injection nozzle 13 via a pipe 14. Alternatively, the powder fluid 3 is filled, and a stirring roller 17 and a blade 18 and a supply roller 19 for supplying the particle group or the powder fluid 3 to the stirring roller 17 are provided. Then, gas is supplied from the gas injection port 12 to the powder supply box 16 to keep the inside of the powder supply box 16 at a positive pressure, and a certain amount of particles or powder fluid is obtained by the rotation of the stirring roller 17 and the action of the blade 18. 3 is guided to the upper part of the powder supply box 16 so that the particle group or the powder fluid 3 can be dispersed from the powder ejection nozzle 13 through the gas outlet 15 and the pipe 14 in a floating state. In the example shown in FIG. 5, a plurality of pipes 14 are partly branched into two pipes 14-1 and 14-2 here.

<Depending on pipe length of charge amount of particles or powder fluid>
The inventors of the present invention have confirmed that the charging of the particle group or the powder fluid 3 is carried from the powder supply box 16 to the powder ejection nozzle 13 while the inner wall of the pipe 14 (14-1, 14-2) and the particle group or This was considered to be due to contact with the powder fluid 3. Therefore, at the time of high-speed filling (1 g / min), the density of the particle group or powder fluid 3 in the pipe 14 increases, and the probability that the inner wall of the pipe 14 and the particle group or powder fluid 3 come into contact decreases. Therefore, we studied to increase the pipe length. The result using the powder fluid 3 is shown in FIG. From the results shown in FIG. 6, it was found that the charge amount decreased with a remarkably short pipe, but the charge amount did not depend on the pipe length if the pipe 14 had a length of 500 mm or more, preferably 1000 mm or more. Similar results were obtained when similar experiments were performed using particle group 3.

<Depends on the particle diameter or the pipe diameter of the charge amount of the powder fluid>
The present inventors considered that since most of the particle groups or powdered fluid 3 moves along the center of the pipe 14 in a laminar flow, no increase in charge amount is observed even when the pipe length is increased. Therefore, it was examined to increase the cross-sectional area of the pipe 14. The length of the pipe 14 is fixed to 1500 mm, the supply speed of the particle group or powdered fluid 3 is fixed to 1 (g / min), and the charged amount of the particle group or powdered fluid 3 filled by changing the cross-sectional area of the pipe 14 is set. Measurements were made. The result using the powder fluid 3 is shown in FIG. From the results shown in FIG. 7, a charge amount exceeding 5 (μC / g) could be obtained with a pipe having a diameter of 6 (mm) or less. From the above results, when the diameter of the pipe 14 is 2r, the value (2 / r) obtained by dividing the inner wall length (2πr) of the cross section of the thinnest part of the pipe 14 by the inner cross-sectional area (πr ² ) is at least It is preferable that the above condition is satisfied, that is, (2 / r = 2/3 = 0.66 (mm ⁻¹ )) or more. Similar results were obtained when similar experiments were performed using particle group 3.

<Depending on the number of branch pipes of the charge amount>
As shown in an example in which the pipe 14 is branched into two in FIG. 5, the powder supply speed from the powder supply box 16 is set to 3 (g) using the powder supply device 11 having two or more branches. / Min), and the change in charge amount according to the number of branches when the diameter of the pipe 14 is 6 (mm) was obtained. The results are shown in FIG. From the results of FIG. 8, it can be seen that the charge amount can be increased as the number of branches increases. It can also be seen that under this condition, the required charge amount (5 μC / g) is reached with one or more pipes 14 having a diameter of 6 (mm) per 1 (g / min).

  Hereinafter, each member which comprises the image display panel used as the object of this invention is demonstrated.

  As for the substrate, at least one substrate is the transparent front substrate 2 from which the color of particles or powder fluid can be confirmed from the outside of the apparatus, and a material having high visible light transmittance and good heat resistance is suitable. The back 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 uniform spacing between the substrates, and if it is thicker than 5000 μm, a thin image display panel will be obtained. Is inconvenient.

  As for the electrodes 5 and 6 when the electrodes are provided on the substrate, the front electrode 6 provided on the side of the front substrate 2 that needs to be transparent on the viewing side is formed of a conductive material that is transparent and can be patterned. Then, metals such as indium oxide, aluminum, gold, silver, and copper, and conductive polymers such as polyaniline, polypyrrole, and polythiophene are exemplified, and examples of the forming method such as vacuum deposition and coating can be given. 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, thickness, and the like of the back electrode 5 provided on the back substrate 1 side are the same as those of the front electrode 6 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 wall 4 is optimally set according to the type of particle group or powder fluid involved in the display, and is not limited in general. However, the partition wall width is 2 to 100 μm, preferably 3 to 50 μm. Is adjusted to 10 to 500 μm, preferably 10 to 200 μm. In forming the partition walls, a both-rib method in which ribs are formed on each of the opposing substrates and then bonded, and a one-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. 9, the display 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 substrate plane direction. The shape is illustrated. It is better to make the portion corresponding to the cross section of the partition wall visible from the display side (the area of the frame portion of the display cell) as small as possible, and the sharpness of the image display increases. Here, examples of the method for forming the partition include a screen printing method, a sand blasting method, a photolithography method, and an additive method. Of these, the photolithography method using a resist film is preferably used.

  Next, the particles used in the image display panel that is the subject of the present invention will be described. 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 brie 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, risor 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 particles used in the present invention preferably have an average particle diameter d (0.5) in the range of 0.1 to 50 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 uniform particle movement becomes possible.

  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.

Next, the powder fluid used in the image display panel that is the subject of the present invention will be described.
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 body are in a state using a flow of gas or liquid. 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, a dispersion system in which a solid or liquid substance is stably suspended as a dispersoid in a gas, and the solid substance is used as a dispersoid in the image display device of the present invention. Is.

The image display panel which is an object 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 in a gas between opposite substrates, at least one of which is transparent. 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, the pulverized fluid used in the present invention is a substance in the intermediate state of both fluid and particle characteristics that exhibits fluidity by itself without borrowing the force of gas or liquid. This powder fluid can be in an aerosol state in particular, and in the image display device of the present invention, a solid substance is used in a state where it floats relatively stably as a dispersoid in the gas.

The range of the aerosol state is preferably such that the apparent volume of the pulverized fluid when it is floated is twice or more that when it is not suspended, more preferably 2.5 times or more, and particularly preferably 3 times or more. Although an upper limit is not specifically limited, It is preferable that it is 12 times or less.
If the apparent volume of the pulverized fluid is less than twice that of the unfloating state, it is difficult to control the display, and if it is more than 12 times, the powder fluid will be overloaded when sealed in the device. Inconvenience in handling occurs. The apparent volume at the maximum floating time is measured as follows. That is, the powdered fluid is put into a closed container that allows the powdered fluid to permeate, and the container itself is vibrated or dropped to create a maximum floating state, and the apparent volume at that time is measured from the outside of the container. Specifically, in a container with a lid (trade name: iBoy: manufactured by ASONE Co., Ltd.) having a diameter (inner diameter) of 6 cm and a height of 10 cm, the powder fluid corresponding to 1/5 of the volume of the fluid when not floating. And set the container on a shaker, and shake at a distance of 6 cm at 3 reciprocations / sec for 3 hours. The apparent volume immediately after stopping shaking is the apparent volume at the maximum floating time.

Moreover, in this invention, what the time change of the apparent volume of a powder fluid satisfy | fills following Formula is preferable.
V ₁₀ / V ₅ > 0.8
Here, V ₅ represents an apparent volume (cm ³ ) 5 minutes after the maximum floating time, and V ₁₀ represents an apparent volume (cm ³ ) 10 minutes after the maximum floating time. In the image display device of the present invention, the apparent volumetric change V ₁₀ / V ₅ of the powder fluid is preferably larger than 0.85, and more preferably larger than 0.9. When V ₁₀ / V ₅ is 0.8 or less, it becomes the same as when ordinary so-called particles are used, and it becomes impossible to ensure the effect of high-speed response and durability as in the present invention.

  Moreover, the average particle diameter (d (0.5)) of the particulate material constituting the powder fluid is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm, and particularly preferably 0.9 to 8 μm. . If it is smaller than 0.1 μm, it is difficult to control the display, and if it is larger than 20 μm, the display is not clear. The average particle diameter (d (0.5)) of the particulate material constituting the powder fluid is the same as d (0.5) in the next particle diameter distribution Span.

The particle substance constituting the powder fluid preferably has a particle size distribution Span represented by the following formula of less than 5, more preferably less than 3.
Particle size distribution Span = (d (0.9) -d (0.1)) / d (0.5)
Here, d (0.5) is a numerical value expressed in μm of the particle diameter that 50% of the particulate material constituting the powder fluid is larger than this and 50% is smaller than this, and d (0.1) is less than this. A numerical value in which the ratio of the particle substance constituting the powder fluid is 10%, expressed in μm, and d (0.9) is the particle diameter in which the particulate substance constituting the powder fluid is 90% μm It is a numerical value expressed by By setting the particle size distribution Span of the particulate material constituting the powder fluid to 5 or less, the sizes are uniform and uniform powder fluid movement becomes possible.

  The above particle size distribution and particle size can be obtained from a laser diffraction / scattering method or the like. When laser light is irradiated to the powder fluid to be measured, a light intensity distribution pattern of diffracted / scattered light is generated spatially, and this light intensity pattern has a corresponding relationship with the particle diameter, so the particle diameter and particle diameter distribution are measured. it can. This particle size and particle size distribution are obtained from a volume-based distribution. Specifically, using a Mastersizer2000 (Malvern Instruments Ltd.) measuring machine, the powdered fluid was introduced into a nitrogen stream, and the attached analysis software (software based on volume reference distribution using Mie theory) Measurements can be made.

  Preparation of powder fluid can be done by kneading and pulverizing the necessary resin, charge control agent, colorant, and other additives, or by polymerization from monomers, and adding existing particles to resin, charge control agent, colorant, and other It may be coated with an agent. Hereinafter, the resin, charge control agent, colorant, and other additives constituting the powder fluid will be exemplified.

  Examples of the resin include urethane resin, acrylic resin, polyester resin, urethane-modified acrylic resin, silicone resin, nylon resin, epoxy resin, styrene resin, butyral resin, vinylidene chloride resin, melamine resin, phenol resin, fluorine resin, etc. Two or more types can also be mixed. In particular, acrylic urethane resin, acrylic urethane silicone resin, acrylic urethane fluororesin, urethane resin, and fluororesin are preferable from the viewpoint of controlling the adhesive force with the substrate.

  Examples of charge control agents include quaternary ammonium salt compounds, nigrosine dyes, triphenylmethane compounds, imidazole derivatives and the like in the case of imparting positive charges, and metal-containing azo compounds in the case of imparting negative charges. Examples thereof include dyes, salicylic acid metal complexes, and nitroimidazole derivatives.

  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 brie 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, risor 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.

Furthermore, in the present invention, it is important to manage the gas in the voids surrounding the particle group or the powder fluid between the substrates, which contributes to the improvement of 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.
1 to 3, the space between the opposing substrate 1 and substrate 2 in FIGS. 1 to 3, the occupied portion of the electrodes 5, 6, the particle group (or powder fluid) 3, the occupied portion of the partition 4, and the device A gas portion that is in contact with a so-called particle group (or powder fluid) excluding the seal portion is meant.
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 the apparatus so that the humidity is maintained. For example, filling of particles or powder fluid, assembly of the substrate, etc. are performed in a predetermined humidity environment, It is important to apply a sealing material and a sealing method to prevent moisture intrusion.

The distance between the substrate in the image display panel of the present invention is not limited as long as the particle group or powder fluid can move and maintain the contrast, but is usually adjusted to 10 to 500 μm, preferably 10 to 200 μm.
The volume occupancy of the particle group or powder fluid in the space between the opposing substrates is preferably 5 to 70%, more preferably 5 to 60%. If it exceeds 70%, the movement of particles or powder fluid is hindered, and if it is less than 5%, the contrast tends to be unclear.

  The image display panel manufactured according to the manufacturing method of the present invention has no image unevenness, display unit of mobile devices such as notebook computers, PDAs, mobile phones, handy terminals, electronic paper such as electronic books and electronic newspapers, signs, posters, Suitable for bulletin boards such as blackboards, display units for calculators, home appliances, automotive products, card display units such as point cards and IC cards, electronic advertisements, electronic POPs, electronic price tags, electronic musical scores, and display units for RF-ID devices Used for.

It is a figure which shows an example of the drive method in the image display panel used as the object of the manufacturing method of this invention. It is a figure which shows the other example of the drive method in the image display panel used as the object of the manufacturing method of this invention. It is a figure which shows an example of the structure of the image display panel used as the object of the manufacturing method of this invention. It is a figure which shows the structure of an example of the powder supply apparatus used with the suitable example of the manufacturing method of the image display panel of this invention. It is a figure which shows the structure of the other example of the powder supply apparatus used with the suitable example of the manufacturing method of the image display panel of this invention. It is a graph for demonstrating the pipe length dependence of the charging amount in the manufacturing method of the image display panel of this invention. It is a graph for demonstrating the pipe diameter dependence of the charge amount in the manufacturing method of the image display panel of this invention. It is a graph for demonstrating the branch pipe number dependence of the charge amount in the manufacturing method of the image display panel of this invention. It is a figure which shows an example of the shape of the partition in the image display panel used as the object of the manufacturing method of this invention. It is a figure for demonstrating the subject in the process of finding the manufacturing method of the image display panel of this invention.

Explanation of symbols

1 Rear substrate 2 Front substrate 3 Particles (powder fluid)
3W white particles (white powder fluid)
3B Black particles (black powder fluid)
4 Partition 5 Back electrode 6 Front electrode 11 Powder supply device 12 Gas injection port 13 Powder injection nozzle 14, 14-1, 14-2 Pipe 15 Gas discharge port 16 Powder supply box 17 Stirring roller 18 Blade 19 Supply roller

Claims (6)

Two substrates, at least one of which is a transparent opposing substrate, on which at least one substrate is formed with a partition wall defining a display cell are overlaid, and a particle group or powder fluid is sealed between them. In the manufacturing method of the image display panel having a structure to stop, when the particle group or powder fluid is dispersed in the display cell, the absolute value of the charge amount of the particle group or powder fluid is 5 (μC / g) or more. The powder supply nozzle having a gas injection port and a gas discharge port connected to the powder injection nozzle is filled with a particle group or powder fluid, and the powder supply box is kept at a positive pressure, whereby the powder injection nozzle floating state since particles or the liquid powders by spraying, image producing method of a display panel, which comprises filling the required amount of the particles or the liquid powders and in the display cells on the board from.   2. The method for manufacturing an image display panel according to claim 1, wherein the absolute value of the charge amount of the particle group or the powder fluid is 100 (μC / g) or less. The particle group or the powder fluid is sprayed from the powder supply box at a speed of 1 (g / min) or more, and the pipe connecting the powder supply box and the powder ejection nozzle is 500 mm or more. Item 3. A method for producing an image display panel according to Item 1 or 2 . Method of manufacturing an image display panel according to claim 1 or 2, wherein the pipe connecting the a powder ejection nozzle powder feed box is not less than 1000 mm. A value obtained by dividing the inner wall length of the cross section of the narrowest portion by the inner cross sectional area of the pipe connecting the powder supply box and the powder jet nozzle is 0.66 (mm ⁻¹ ) or more. The manufacturing method of the image display panel of any one of Claims 1-4 . The structure of pipe connecting the powder feed box and the powder ejection nozzle, branches into a plurality of in the middle, according to claim 1, characterized in that it has a structure to join again Manufacturing method of image display panel.

Images