KR20100060521A - Porous charged particles having improved reflecting efficiency for image display device and method for manufacturing the same - Google Patents

Abstract

PURPOSE: Porous charged particles are provided to enable a user to conveniently control used amount of a fluorescent pigment and to improve optical properties of an electronic paper display device by increasing white reflectivity of a first layer of the charged particles. CONSTITUTION: Porous charged particles(50) for an image display device comprises pigment having a grain diameter size more than 0.2 micron. A method for manufacturing the charged particles comprises the following steps: preparing continuous phase liquid; preparing a dispersed solution by dispersing pigment with a diameter size more than 0.2 micron on a solution including an acrylic monomer, a crosslinking agent, and a charge control agent; manufacturing dispersed phase liquid by adding a cosolvent to the dispersed solution; and forming a polymer by the continuous phase liquid and the dispersed phase liquid.

Description

POROUS CHARGED PARTICLES HAVING IMPROVED REFLECTING EFFICIENCY FOR IMAGE DISPLAY DEVICE AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a charged particle used in an image display device and a manufacturing method thereof. More particularly, the present invention relates to a porous charged particle filled for image realization of an image display apparatus such as electronic paper, and to a charged particle having improved reflectance and a method of manufacturing the same.

An image display apparatus using charged particles is a reflective display that forms a substrate by coating a transparent conductive film on a thin, bendable film substrate such as paper or plastic, drives charged particles between the substrates, and requires no external light source.

Such an image display device is also drawing attention as a next-generation e-paper that will follow a liquid crystal display (LCD), a plasma display panel (PDP) and an organic light emitting device.

In particular, the electronic paper display device is a key element for implementing a flexible display, and is driven based on a principle of applying mobility to a conductive material by applying an electromagnetic field. That is, after the charged particles are distributed between the thin flexible substrates, the data is expressed by the change in the arrangement of the charged particles due to the change in polarity of the electric field.

In this case, if the orientation of the charged particles occurs at any of the poles, there is no change in the position of the particles even when the voltage is removed due to the memory effect, so that the image is maintained as it is and the same effect as printing ink on paper can be obtained.

Therefore, since the visual fatigue is very low because there is no self-luminous, comfortable viewing such as viewing a real book or paper document is possible. In addition, the use of a flexible substrate has the advantage of ensuring flexibility and portability, and thus, great expectations are expected for future flat panel display technologies.

In addition, as mentioned above, since the image once implemented is maintained for a long time unless the substrate is reset, the power consumption is very low, and thus it is useful as a portable display device.

1 is a cross-sectional view showing the structure of a general electronic paper display device.

As shown in FIG. 1, the cell structure of a conventional electronic paper display device using charged particles is characterized in that the upper and lower substrates 10 and 60 are formed of either plastic or glass, and the driving voltage of the device on the upper and lower substrates. Upper and lower electrodes 20 and 70 formed of transparent electrodes ITO to be applied, upper and lower insulating layers 30 and 80 selectively coated on the upper and lower electrodes, and partition walls 40 that separate cells from the cells. And black and white charged particles 50 charged with (-) and (+) charges respectively present between the electrodes.

In the electronic paper display device having such a structure, when sufficient voltage is applied to the electrodes 20 and 70, the charged particles 50 move to each electrode according to the polarity. For example, when a negative voltage and a positive voltage are applied to the upper and lower electrodes 20 and 70, respectively, the black and white charged particles are directed toward the lower substrate 10 and the upper substrate 60 by the Coulomb force. Will move. Therefore, when the upper substrate is the observation surface, it is displayed in white. Using this principle, voltages are initially applied to make all cells appear white, and then only black cells are displayed by applying opposite voltages to the desired cells to express pictures or characters.

As such, an electronic paper having a structure in which black and white charged particles are included between the substrate and the partition walls to express a picture or a character is called a toner type electronic paper, and the most important characteristic of the toner type electronic paper display device is a display. High contrast ratio of.

In order to show the high contrast ratio of the electronic paper, the white particles should be sufficiently bright and the black particles should be dark enough. In other words, the white particles should have high white reflectance, while the black particles should have low reflectance.

In order to increase the white reflectance of the white particles, a method of stacking the particles in multiple layers in the partition wall may be considered. However, when stacking the particle layer of several layers, there is a disadvantage that the driving voltage is increased due to the height of the partition wall.

It is also important to increase the white reflectance of the electronic paper display device, but it is also important to display a low driving voltage in consideration of ease of use. Therefore, in order to exhibit a low driving voltage, it is necessary to lower the height of the partition walls that can fill the particles together. Therefore, the height of the partition walls is limited, and it is most preferable that only one layer of particles are filled in the partition walls of the limited height.

On the other hand, most white particles show more than 90% of white reflectance when stacked in multiple layers, but more than 10% of white reflectance is difficult with one layer, and the reflectance is more canceled when partitions exist. Research is ongoing to increase white reflectance.

For example, a technique for forming a pigment having a specific particle size on the surface of white particles with an external additive has been studied, but such a technique adds a process of forming a pigment on the surface of white particles, thereby producing a manufacturing cost of an electronic paper display device. Since the amount of the pigment that can be used is limited, the desired white reflectance enhancement effect is difficult to be expected, and there is a problem that the image quality may be degraded.

Accordingly, there is a need for a technology that can be manufactured by a simple manufacturing process and that can effectively improve the white reflectance of a single layer of white particles in an electronic paper display device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a charged particle for an image display device and a method of manufacturing the same, which can further improve the optical characteristics of an electronic paper display device even when only one layer is filled in a partition wall by increasing the white reflectance of one charged particle layer. .

In order to solve the above problems, the present invention provides a charged particle for an image display device as a charged particle for an image display device, containing a pigment having a particle size of 0.2 ㎛ or more.

In general, the charged particles for electronic paper show an image by reversing black and white, and since white particles play a role of paper, white particles having a high white reflectance at the paper level are required.

Therefore, since the charged particles for the image display device according to the present invention contain a pigment having a particle size of 0.2 μm or more, the pigments have excellent dispersibility in the charged particles, and thus a larger amount can be added than the smaller pigments. Therefore, in the image display apparatus, the white reflectance of one particle layer can be further improved.

The present invention also provides an image display apparatus including the upper and lower substrates, partitions provided between the substrates, and charged particles according to the present invention, which are filled between the partitions.

The present invention also includes the steps of (a) preparing a continuous aqueous solution, (b) preparing a dispersion by dispersing a pigment having a particle size of 0.2 ㎛ or more in a solution containing an acrylic monomer, a crosslinking agent, a charge control agent, (c (D) preparing a dispersed phase liquid by adding a cosolvent to the dispersion, and (d) mixing the aqueous continuous phase liquid and the dispersed phase liquid to form a polymer. Provide a method.

According to the present invention, it is possible to conveniently adjust the amount of fluorescent pigment used, and to provide a charged particle for an image display device with remarkably improved reflection efficiency and an image display device including the same.

In order to increase the white reflectivity of one layer of charged particles, a charged particle including a white pigment was prepared, and the white reflectivity of the first layer of particles was measured. As a result, the white reflectance increased as the amount of the pigment, such as titanium dioxide, increased.

However, the general white particles have a limited content of pigments such as titanium dioxide, and even when the amount of the pigment is added, the dispersibility of the pigment is poor, which may lower the image quality of the image display device. There is a problem that the viscosity is rapidly increased, making white particles difficult, and there is a limit in sufficiently increasing the reflectance of the particle 1 layer to a predetermined level or more.

The inventors of the present invention have been able to effectively improve the white reflectance of one layer of charged particles by incorporating a pigment having a particle size of 0.2 µm or more into charged particles for an image display device after extensive research.

Hereinafter, the present invention will be described in detail.

In the charged particles according to the present invention, the pigment having a particle size of 0.2 μm or more may be present in a sufficiently dispersed form in the resin constituting the charged particles. The type of resin may be those known in the art.

Preferably, the charged particles have a particle size of 0.5 to 50 μm, and when the particle size is less than 0.5 μm, the white reflectance drops and the cohesion between particles increases. When the charged particle exceeds 50 μm, the driving voltage becomes high and moves within a limited partition cell. There is a problem that many particles that are not.

The charged particles are not particularly limited as long as they can be used as the white particles of the image display device, but may be porous charged particles having a structure in which regular or irregular irregularities are formed on the particle surface.

The charged particles may be formed by polymerizing an acrylic monomer including a cosolvent, a crosslinking agent, a charge control agent and a pigment in an aqueous continuous phase liquid.

In general, when preparing charged particles, the method includes attaching silica to the surface of the charged particles, but the charged particles prepared by the above method may have a porous surface to ensure sufficient fluidity without adhesion of the silica particles. . In addition, the silica particles adhering to the surface of the charged particles are desorbed during the driving of the image display device, thereby reducing the image quality.

In this case, the charged particles can be easily produced by the method of adding the dispersed phase liquid containing the acrylic monomer, the crosslinking agent, the charge control agent, the pigment and the cosolvent to the aqueous continuous phase liquid.

In this case, the co-solvent enters the dispersed phase solution together with the acrylic monomer, the cross-linking agent, the charge control agent, and the white pigment, and undergoes a polymerization reaction. As the co-solvent exits out of the polymerization process, pores are formed at the co-solvent site. Is formed.

The pigment is titanium dioxide as a white pigment (TiO _2), barium sulfonic fade (BaSO _4), barium titanate marinade (BaTiO _3), strontium titanate marinade (SrTiO _3), calcium titanate (CaTiO _3), lead titanate marinade (PbTiO ₃ ), tin dioxide (SnO ₂ ), magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), silica (SiO ₂ ), iron oxide (Fe ₂ O ₃ ), zirconia (ZrO ₂ ) and the like can be used. It is particularly preferable to use titanium dioxide.

In addition, the pigment is preferably used in an amount of 5 to 100 parts by weight, more preferably 5 to 50 parts by weight, per 100 parts by weight of the mixture of the acrylic monomer and the crosslinking agent. When the pigment is less than 5 parts by weight, the coloring effect is insignificant, and when the pigment is more than 100 parts by weight, a problem that the pigment comes out of the particles occurs.

For reference, a pigment having a particle size of 1 μm or less, which was conventionally used, could be added up to 10 parts by weight per 100 parts by weight of the mixture. There was a problem. However, the pigment having a particle size of 0.2㎛ or more can be added 10 parts by weight or more.

On the other hand, the pigment is not particularly limited as long as it has a particle size of 0.2 μm or more, preferably has a particle size of 0.2 to 1 μm, and particularly preferably has a particle size of 0.2 to 0.5 μm.

The aqueous continuous supernatant may be prepared by dissolving a dispersion stabilizer in water. The dispersion stabilizer is polyvinyl alcohol, methyl cellulose, ethyl cellulose, polyvinyl pyrrolidone, styrene-methylmethacrylate copolymer Water-soluble polymers such as styrene-maleic anhydride copolymer; Anionic surfactants such as sodium oleic acid, sodium lauryl sulfate, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxy Nonionic surfactants such as ethylene fatty acid esters, sorbitane fatty acid esters, polyoxy sorbitan fatty acid esters, polyoxyethylene alkyl amines and glycerin fatty acid esters, and lauryl amine acetate, alkyl amine salts, Surfactants such as cationic surfactants including quaternary ammonium such as lauryltrimethyl ammonium chloride; Or phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, pyrophosphoric acid calcium, pyrophosphoric acid magnesium, pyrophosphoric acid aluminum, and pyrophosphoric acid zinc pyrophosphoric acid salts; Inorganic dispersants such as calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium lactate, barium sulfate, colloidal silica and fumed silica can be used. Preferably, polyvinyl alcohol can be dissolved in water to prepare an aqueous continuous supernatant.

In addition, the dispersion stabilizer is preferably used 0.1 to 10 parts by weight based on 100 parts by weight of the acrylic monomer or copolymer. When the dispersion stabilizer is less than 0.1 part by weight, dispersion stability is not sufficient, and when the dispersion stabilizer exceeds 10 parts by weight, it is difficult to remove the remaining dispersion stabilizer.

The acrylic monomer is a C _1-12 alkyl (meth) acrylate, isobutyl (meth) acrylate, t- which can cause a radical reaction by a polymerization initiator. Butyl (meth) acrylate [t-butyl (meth) acrylate], glycidylhexyl (meth) acrylate [glycidylhexyl (meth) acrylate], 2-hydroxyethyl (meth) acrylate [2-hydroxyethyl (meth) acrylate], polyethyleneglycol (meth) acrylate, glycidyl (meth) acrylate, and dimethyl (ethyl) aminoethyl (meth) acrylate [dimethyl (ethtyl) ) aminoethyl (meth) acrylate] may be one or more compounds selected from the group consisting of.

The crosslinking agent crosslinks the monomers to form a porous material on the surface of the charged particle, and includes divinyl benzene, diallyphtalate, diallyacrylamide, and triallyl. Allyl compounds such as iso) cyanurate, (poly) ethylene glycol di (meth) acrylate, and (poly) propylene glycol di (meth) Acrylate [(poly) propylene glycoldi (meth) acrylate], trimethylol propane tri (meth) acrylate, glycerol tri (meth) acrylate, allyl One or more compounds selected from (meth) acrylate [ally (meth) acrylate] and (poly) alkylene glycol di (meth) acrylate [(poly) alkylene glycol di (meth) acrylate] can be used.

In addition, the crosslinking agent is preferably in the range of 20 to 80 parts by weight based on 100 parts by weight of the monomer. If the content of the crosslinking agent is less than 20 parts by weight, no porous is formed on the surface of the charged particles, and if the content exceeds 80 parts by weight, the polymerization reaction may not be smooth, resulting in a drop in yield.

On the other hand, a charge control agent is used to control the charge of the monomer, but the type of the charge control agent is not particularly limited, but ions or anions may be added to the styrene resin, the acrylic resin, and the copolymer of the styrene and acrylic resin. Preference is given to using organic charge control agents which are substituted and have a positive or negative charge.

At this time, since the monomer is polymerized, the organic charge control agent is nonpolar than the polymer region in which the organic charge control agent is formed, and is polarized rather than the cosolvent, thereby causing phase separation between the polymer region and the cosolvent, thereby easily forming porous particles.

In addition to using the organic charge control agent, the charge amount is controlled by the inorganic charge control agent, and between the polymer region and the cosolvent by adding styrene and an acrylic copolymer or an acrylic polymer having intermediate polarity between the formed polymer and the cosolvent. Phase separation may occur to produce porous particles. Examples of the inorganic charge control agent include negative combinations such as sub-bonded complexes including vanadium, cobalt, nickel or copper, salicylic acid chelate metal complexes including copper, titanium, or iron, caralisrene compounds, boron-containing compounds, and the like. -) Charge charge control agent, positive charge charge control agent such as nigrosine (negrosine dyes) and quaternary ammonium salts can be selected and used.

The charge control agent is preferably used in 0.1 to 10 parts by weight per 100 parts by weight of the mixture of the acrylic monomer and the crosslinking agent. If the charge control agent is less than 0.1 parts by weight, the charge amount is too low, if it is more than 10 parts by weight, the charge amount is too high, the reaction stability is deteriorated and excessive coagulation occurs.

In order to prepare the charged particles or the porous charged particles, a cosolvent must be used together, and the cosolvent is preferably a nonpolar polymer rather than a polymer region formed by polymerization. The cosolvent is not particularly limited and may be selected from cyclohexane, normal hexane, hexane, normal-heptane, isohexane, isooctane, methyl ethyl ketone, methyl isobutyl ketone and the like.

The cosolvent content is preferably 5 to 200 parts by weight based on 100 parts by weight of the monomer. When the cosolvent content is less than 5 parts by weight, the porosity is lowered and the reflectance is lowered. When the cosolvent content is more than 200 parts by weight, the pores become large and uneven, thereby decreasing the reflectance.

The present invention also provides an image display apparatus including an upper and lower substrates, a partition wall disposed between the substrates, and the charged particles filled between the partition walls.

Since the image display apparatus including the charged particles according to the present invention includes a pigment having a particle size of 0.2 μm or more inside the charged particles, the pigment dispersibility is good, and a sufficient amount of the pigment may be included, thereby being excellent even at a low driving voltage. White reflectance.

In addition, a UV blocking film may be attached to at least one surface of the image display device if necessary, and the UV blocking film is not particularly limited as long as it is commonly used by those skilled in the art.

The present invention also includes the steps of (a) preparing a continuous aqueous solution, (b) preparing a dispersion by dispersing a pigment having a particle size of 0.2 ㎛ or more in a solution containing an acrylic monomer, a crosslinking agent, a charge control agent, (c A) adding a cosolvent to the dispersion to produce a dispersed solution, and (d) mixing the aqueous continuous solution and the dispersed solution to form a polymer, thereby providing a method for producing charged particles for the image display device. do.

In the method of manufacturing a charged particle for an image display device according to the present invention, by using a pigment having a particle size of 0.2 μm or more, it is easy to increase the amount of the pigment contained in the charged particle as necessary, and the white reflectance can be improved by a simple process. An excellent charged particle for an image display device can be produced.

On the other hand, the progress of the step (b) and (c) is not particularly limited in order, it may proceed in the reverse order or at the same time if necessary.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples are only for illustrating the present invention, and the protection scope of the present invention is not limited to the following Examples.

Example 1

600 g of distilled water and 2 g of polyvinyl alcohol were dissolved in a 1 L reactor, and an aqueous continuous phase liquid was prepared by maintaining the reactor temperature at 60 ° C.

90g of methylmethacrylate and 60g of ethylene glycol dimethacrylate, a crosslinking agent, were dissolved in a monomer, 0.75g of FCA201PS of Fujikura Kasei, an organic positive charge control agent, and then 0.35 in size. 15 g of COTIOX R730 and 0.3 g of 0.3 mm Zirconia beads, which are rutile titanium dioxide manufactured by Cosmo Chemical Co., Ltd., were stirred at 1000 rpm for 1 hour, and then the beads were completely removed. Dissolved solution was prepared by dissolving 0.5 g of (wako) V-65 (2-2'-azobis (2,4-dimethylvaleronitrile)) in 50 g of cyclohexane in 110.5 g of cyclohexane.

The dispersed solution was added to the aqueous continuous solution, emulsified with a homogenizer at 6500 rpm for 5 minutes, polymerized for 10 hours, and washed and dried to prepare particles.

In order to observe the surface of the prepared particles, Hitachi S4800, a scanning electron microscope, was used, and the average particle diameter and the standard diameter of the particle diameter were determined using a BECJMAN COULTER particle size analyzer.

An AR (Anti-reflective) film was used as a pressure-sensitive adhesive in order to make a specimen in which the prepared particles were arranged in one layer, and after the particles to be evaluated are sufficiently brought into contact with the pressure-sensitive adhesive side of the AR film, air was blown. Particles were removed except the particles directly adhered to the pressure-sensitive adhesive surface to prepare a specimen in which the particles were arranged in one layer.

The prepared specimens were measured for transmittance reflectance at 550 nm using a Shimadzu UV Vis spectrometer (UV-3600).

Example 2

Particles were prepared in the same manner as in Example 1, except that COTIOX KA100, an anatase titanium dioxide of 0.35 μm, was used.

Example 3

Particles were prepared in the same manner as in Example 1, except that TIPAQUE CR-60-2, an anatase-type titanium dioxide manufactured by Ishihara, which was 0.21 μm, was used.

Example 4

Particles were prepared in the same manner as in Example 1, except that Ti-PURE R706, which was rutile titanium dioxide (Dupont) having 0.35 μm, was used.

Example 5

Particles were prepared in the same manner as in Example 1, except that 30 g of COTIOX R730, a rutile titanium dioxide of 0.35 μm, was used.

Example 6

Particles were prepared in the same manner as in Example 1, except that 45 g of COTIOX R730, a rutile titanium dioxide of 0.35 μm, was used.

Comparative Example 1

Particles were prepared in the same manner as in Example 1 except that TAF502J, an anatase-type titanium dioxide manufactured by Fuji Titan of 0.1 µm, was used.

Comparative Example 2

Particles were prepared in the same manner as in Example 1, except that 7.5 g of EUSOLEX T-ECO, a rutile titanium dioxide manufactured by Merck of 0.02 μm or less, was used.

Comparative Example 3

Particles were prepared in the same manner as in Example 1, except that 7.5 g of AEROXIDE P-25, a fumed titanium dioxide manufactured by Degussa, which was 0.025 μm, was used.

Comparative Example 4

Particles were prepared in the same manner as in Example 1, except that 7.5 g of AEROXIDE NKT-90, a fumed titanium dioxide manufactured by Degussa, which was 0.014 μm, was used.

Comparative Example 5

Particles were prepared in the same manner as in Example 1 except that 45 g of anatase-type titanium dioxide TAF502J manufactured by Fuji Titan of 0.1 µm was used, but the particles could not be prepared because the viscosity of the dispersed solution was rapidly increased. .

Comparative Example 6

Particles were manufactured in the same manner as in Example 1 except that 15 g of EUSOLEX T-ECO, a rutile titanium dioxide manufactured by Merck of 0.02 μm or less, was used to prepare particles by rapidly increasing the viscosity of the dispersed solution. I could not.

Comparative Example 7

Particles were prepared in the same manner as in Example 1 except that 15 g of AEROXIDE P-25, a fumed titanium dioxide of 0.025 μm, was used, but the viscosity of the dispersed phase solution was rapidly increased. I could not.

Comparative Example 8

Particles were prepared in the same manner as in Example 1 except that 15 g of AEROXIDE NKT-90, a fumed titanium dioxide of 0.014 μm, was used. I could not.

The content and type of the composition used in Examples 1 to 6 are shown in Table 1, and the physical properties of the charged particles used in Examples 1 to 6 are shown in Table 3.

The content and type of the composition used in Comparative Examples 1 to 8 are shown in Table 2, and the physical properties of the charged particles used in Comparative Examples 1 to 4 are shown in Table 4.

 TABLE 1

TABLE 2

[Table 3]

[Table 4]

In Examples 1 to 4, 10 wt% of titanium dioxide having a size of 0.2 μm was added based on 100 parts by weight of the monomer and the crosslinking agent. Although there is a slight difference depending on the type of titanium dioxide, most of them show good particle single layer white reflectance.

In Examples 5 and 6, to increase the white reflectance of the particle 1 layer, the COTIOX R730 manufactured by Cosmo Chemical Co., Ltd. used in Example 1 was increased by 20 wt% and 30 wt%, respectively, based on 100 parts by weight of the monomer and the crosslinking agent. As the amount of titanium dioxide added increased, the white reflectance of one particle layer could be increased.

In Comparative Examples 1, 3 and 4, titanium dioxide having a size of 0.2 μm or less was used, and the particle one layer white reflectance was lower than that of titanium dioxide having a size of 0.2 μm or more.

In Comparative Example 5, the Fuji titanium TAF502J used in Comparative Example 1 was increased to 30% by weight based on 100 parts by weight of the monomer and the crosslinking agent, but there was a problem in that the viscosity of the dispersed phase solution rapidly increased due to the dispersibility of titanium dioxide.

In Comparative Example 2 using Merck's EUSOLEX2 T-ECO, even though the size of titanium dioxide was as small as 0.02 µm or less, good white reflectance was obtained. However, titanium dioxide having a size of 0.025 µm or less was used as in Comparative Examples 2, 3 and 4. Since the dispersibility is further lowered, even if only 10% by weight based on 100 parts by weight of the monomer and the crosslinking agent, there is a problem that the viscosity of the dispersed solution is rapidly increased, there is a limit to increase the white reflectance of the particles.

In conclusion, the charged particles for an image display apparatus including titanium dioxide having a particle size of 0.2 μm or more according to the present invention can add a large amount of titanium dioxide into the charged particles and have good dispersibility of titanium dioxide. The white reflectance of was found to be excellent.

1 is a cross-sectional view illustrating a structure of an electronic paper display device using general charged particles.

<Description of Major Symbols in Drawing>

10: Upper part

20: upper electrode

30: upper insulating layer

40: bulkhead

50: charged particle

60: lower substrate

70: lower electrode

80: lower insulating layer

Claims (21)

A charged particle for an image display device, wherein the charged particle for an image display device contains a pigment having a particle size of 0.2 µm or more. The charged particle for an image display device according to claim 1, wherein the charged particle is formed by polymerizing an acrylic monomer including a cosolvent, a crosslinking agent, a charge control agent and a pigment in an aqueous continuous phase liquid. The charged particle for an image display apparatus according to claim 2, wherein the charged particle is prepared by adding a dispersed phase liquid containing an acrylic monomer, a crosslinking agent, a charge control agent, a pigment, and a cosolvent to an aqueous continuous phase liquid. The charged particle for an image display device according to claim 1, wherein the charged particle is porous. The method according to claim 1, wherein the pigment is titanium dioxide (TiO _2), barium sulfonic fade (BaSO _4), barium titanate marinade (BaTiO _3), strontium titanate marinade (SrTiO _3), calcium titanate (CaTiO _3), lead titanate marinade (PbTiO ₃ ), tin dioxide (SnO ₂ ), magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), silica (SiO ₂ ), iron oxide (Fe ₂ O ₃ ) and zirconia (ZrO ₂ ) Charged particles for an image display device, characterized in that selected. The charged particle for an image display device according to claim 1, wherein the pigment is titanium dioxide (TiO ₂ ). The charged particle of claim 1, wherein the pigment has a particle size of 0.2 to 1 μm. The charged particle of claim 1, wherein the pigment has a particle size of 0.2 μm to 0.5 μm. The method according to claim 2, wherein the aqueous continuous supernatant is a water-soluble polymer; Surfactants; Or a dispersion stabilizer. The allyl compound of claim 2, wherein the crosslinking agent is divinyl benzene, diallyl phthalate, diallyacrylamide, triallyl (iso) cyanurate, or the like. ((Poly) ethylene glycol di (meth) acrylate], (poly) propylene glycol di (meth) acrylate [(poly) propylene glycoldi (meth) acrylate], trimethylol Propane tri (meth) acrylate [trimethylol propane tri (meth) acrylate], glycerol tri (meth) acrylate [glycerol tri (meth) acrylate], allyl (meth) acrylate [ally (meth) acrylate], and (poly A charged particle for an image display device comprising at least one compound selected from the group consisting of: (alkyl) glycol di (meth) acrylate [(poly) alkylene glycol di (meth) acrylate]. The charged particle for an image display device according to claim 2, wherein the charge control agent is more polar than the polymer region formed while the monomer is polymerized and is nonpolar than the cosolvent. The method of claim 2, wherein the charge control agent is a group consisting of a styrene-based resin, an acrylic resin and a charge control agent having a positive (+) charge or a negative (-) charge by the substitution of a cation or an anion to a copolymer of styrene-based and acrylic-based acrylics. Charged particles for an image display device, characterized in that selected from. The method of claim 2, wherein the cosolvent is selected from the group consisting of cyclohexane, normal hexane, hexane, normal-heptane, isohexane, isooctane, methyl ethyl ketone and methyl isobutyl ketone Charged particles for an image display device. The charged particle for an image display apparatus according to claim 2, wherein the dispersion stabilizer is mixed in a range of 0.1 to 10 parts by weight based on 100 parts by weight of the monomer. The charged particle of claim 2, wherein the charge control agent is mixed in a range of 0.1 to 10 parts by weight based on 100 parts by weight of the mixture of the monomer and the crosslinking agent. The charged particle for an image display apparatus according to claim 2, wherein the crosslinking agent is mixed in a range of 20 to 80 parts by weight based on 100 parts by weight of the monomer. The charged particle for an image display apparatus according to claim 2, wherein the pigment is mixed in the range of 5 to 100 parts by weight based on 100 parts by weight of the mixture of the monomer and the crosslinking agent. The charged particle for an image display apparatus according to claim 2, wherein the cosolvent is mixed in a range of 5 to 200 parts by weight based on 100 parts by weight of the monomer. An image display device comprising the upper and lower substrates, partitions provided between the substrates, and charged particles for the image display device according to any one of claims 1 to 18, which are filled between the partitions. The image display apparatus according to claim 19, wherein a UV blocking film is attached to at least one surface of the upper and lower substrates. (a) preparing an aqueous continuous supernatant, (b) preparing a dispersion by dispersing a pigment having a particle size of 0.2 μm or more in a solution containing an acrylic monomer, a crosslinking agent, and a charge control agent, and (c) sharing the dispersion solution. A method for charging an image display device according to any one of claims 1 to 18, which comprises adding a medium to prepare a dispersed liquid and (d) mixing the aqueous continuous liquid and the dispersed liquid to form a polymer. Method of producing the particles.

Images