KR20090127554A - Fluent particle composition and method of manufacuring fluent particle using thereof - Google Patents

Abstract

PURPOSE: A fluent particle composition is provided to ensure excellent bond durability and low aggregation between particles by forming chemical bond of external additive agent and polymer particles. CONSTITUTION: A method for preparing a fluent particle composition comprises the steps of: mixing solvent 100.0 parts by weight, monomer particles 5-20 parts by weight, synthetic initiator 0.01-0.5 parts by weight, and silica nanoparticle synthesized material 0.5-10 parts by weight; polymerizing the mixed solution at a temperature of 40-90 °C for 15-24 hours; and drying the solution.

Description

FLUENT PARTICLE COMPOSITION AND METHOD OF MANUFACURING FLUENT PARTICLE USING THEREOF

The present invention relates to a flowable particle composition and a method for producing the flowable particles using the same, and more particularly, to generate charged particles by an emulsion-free polymerization method by appropriately using a reaction such as a synthetic initiator and a silica nanocomposite. The present invention relates to a flowable particle composition for an electronic paper image display device that controls agglomeration of ions and provides flowable particles with excellent durability and flowability, and a method of manufacturing the flowable particles using the same.

BACKGROUND ART Conventionally, as an image display apparatus replacing a liquid crystal display (LCD), an electronic paper image display apparatus using techniques such as an electrophoresis method, an electrochromic method, a thermal method, and a two-color particle rotation method has been proposed. These prior arts are considered to be a technology that can be used in an inexpensive image display device because of the advantages of having a wider viewing angle closer to a normal printed matter, a smaller power consumption, and a memory function than LCDs. The development of electronic paper image display devices and the like is expected.

The dual electronic paper image display device uses a rapid movement of microparticles by an electric field to electrostatically move charged particles floating in a certain space to display colors. Due to the memory effect, even if the voltage is removed, the image does not disappear because there is no change in the position of the particles, so that the effect is printed on paper as ink. In other words, it does not emit light by itself, but the visual fatigue is very low, so it is possible to enjoy a comfortable viewing like a real book, and the panel's flexibility is high enough to bend and the thickness can be formed very thin. There is great expectation as a display device technology. In addition, as mentioned, power consumption is extremely low since the displayed image is maintained for a long time unless the panel is reset, thereby making it excellent as a portable display device. In particular, the low cost due to the simple process and low cost materials is expected to contribute to the popularization of electronic paper image display devices.

Electronic paper image display device technology generally used includes an electrophoretic method of microencapsulating a dispersion consisting of dispersed particles and a colored solution and disposing it between opposing substrates to cause particles to move in the liquid; Without using a solution, two or more kinds of particles having different colors and charging characteristics are enclosed between at least one transparent substrate, and an electric field is applied to the particles from an electrode pair consisting of electrodes formed on one or both of the substrates. A collision charging method has been proposed in which a charged particle having a different polarity is driven and moved in different directions by a Coulomb force to display an image.

1 is a cross-sectional view showing a cell structure of such a collision charging type electronic paper image display apparatus. As illustrated, the collision charging type electronic paper image display device includes an upper substrate 10 and a lower substrate 20 formed of any one of the plastics and glass, and a driving voltage of an element on the substrate. The upper electrode 30 and the lower electrode 40, the upper substrate 10 and the lower substrate 20 formed to maintain a constant distance between the partition wall 50 separating the cells and the cell, and the upper electrode ( It comprises a positive charge particle 60 and a negative charge particle 70 present between the 30 and the lower electrode 40.

In the collision charging type electronic paper image display device having the above structure, when sufficient voltage is applied to the upper electrode 30 and the lower electrode 40, the charged particles 60 and 70 are charged according to the applied electrode polarity. Drawn to each electrode. For example, when − voltage is applied to the lower electrode 40 and + voltage is applied to the upper electrode 30, the black charged particles 60 positively charged by the coulomb force move toward the lower substrate 20. In addition, the negatively charged white charged particles 70 move toward the upper substrate 10. As a result, since the white charged particles 70 are located on the upper substrate 10 side, the white charged particles 70 appear white when viewed from the outside. On the contrary, when + voltage is applied to the lower electrode 40 and − voltage is applied to the upper electrode 30, the black charged particles 60 move toward the upper substrate 10, and thus appear black.

Regardless of any of the above electrophoretic and collision charging methods, a technique for forming a charged particle having a fluidity (hereinafter, referred to as a 'fluid particle') should be accompanied, and the fluid particle is generally illustrated in FIG. 2. As shown, the structure in which the inorganic external additive 4, such as a silicon particle and a coupling agent, is coated on the surface of the polymer particle 1 containing the charge control agent 2 and the pigment | dye / dye 3 is shown.

The flowable particles include an external blending method using a mixer by adding an external additive 4 to a dispersion solvent including a polymer particle, a charge control agent, and a dye / dye (3). have. In the flowable particles in this manner, the polymer particles 1 and the external additives 4 are physically bonded, and due to the limitation of the durability of the physical bonding, the external components easily fall off. When the external additive 4 easily falls in this way, the charged particles cannot sufficiently respond to the same applied voltage, and since the charging characteristics also change easily, there arises a problem of deterioration in image quality. In addition, the longer the use time due to the departure of the external additive, there is a problem that the probability of occurrence of aggregation between the particles increases.

The present invention is to solve the above problems, an object of the present invention is to form a bond between the external additive and the polymer particles by chemical bonding, excellent durability of the bond, and provides a flowable particle composition with little occurrence of aggregation between particles It is.

In addition, another object of the present invention, by using a monomer as a seed (seed), without using a separate polymer particles to produce flow particles for the electronic paper image display device in the polymer polymerization step, it is economically effective fluid particles It is to provide a manufacturing method.

Hereinafter, a flowable particle composition and a method for preparing flowable particles using the same according to the present invention will be described.

The fluid particle composition which concerns on this invention consists of 5-20 weight part of monomer particles, 0.01-0.5 weight part of synthesis initiators, and 0.5-10 weight part of silica nanoparticles with respect to 100 weight part of solvents.

In addition, the method for producing flowable particles according to the present invention includes a mixing step of mixing the flowable particle composition; A polymerization step of polymerizing the dispersed solution at the temperature of 40 to 90 ° C. for 15 to 24 hours; It characterized in that it comprises a drying step of drying the solution.

That is, the present invention is a composition and a polymerization method for polymerizing polymer particles by a monomer and a synthesis initiator. More specifically, the flowable particle composition according to the present invention, specifically for surfactant-soap-free emulsion polymerization of a polymer without a surfactant (surfactant) by the combination of the synthetic initiator and silica nanoparticles, specifically The emulsion polymerization composition excluded and the fluid particle manufacturing method using the same are provided.

Polymerization of the polymer is mainly performed by emulsion polymerization using a surfactant such as sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB), dispersion polymerization and suspension polymerization. Can be divided into In general, when the surfactant is used, small nanoparticles of 100 nm or less can be obtained, the particle size distribution is narrow, and the reaction rate is faster than dispersion and suspension polymerization. This is because by adding a ionic surfactant, micelles surrounding the polymer particles are formed to obtain a more stable colloidal phase.

However, in order to manufacture the flowable particles for electronic paper, since the process of reacting the silica nanoparticles to the polymer particles thus formed is required, the number of processes is increased, and cumbersome operations such as attaching a separate hydrophilic functional group to the formed polymer are required. As a result of repeated experiments, the inventors of the present invention have carried out a soap-free emulsion polymerization (hereinafter referred to as 'emulsification-free polymerization') excluding a surfactant to prepare the flowable particles. It has been proposed a manufacturing method that can increase the yield by reducing the number of operations and economical to obtain particles.

According to the non-emulsification polymerization according to the present invention, the surfactant is not entered during the polymerization process, but the surfactant is added by the interaction thereof, including an ionic synthesis initiator or a functional group having ionic properties in the polymer chain to be polymerized. Similar levels of colloidal stabilization were achieved.

In addition, by utilizing the electrostatic attraction between the cation of the synthetic initiator and the anion of the silica nanoparticles, it was possible to obtain the effect that a strong chemical bond between the external additive and the polymer particles is already generated at the time of polymer particle generation.

As a result of the experiment, the silica nanoparticles adhered well to the surface of the polymer particles, and were able to form flowable particles having a small particle size distribution.

Thus, first look at each configuration of the fluid particle composition according to the present invention, and then look at the effects of the present invention through the production method and various embodiments.

As the solvent used in the present invention, water or alcohols may be used alone or mixed. The monomer particles are not particularly limited as long as they are capable of non-emulsifying polymerization. Preferably, styrene, methyl methacrylate and ethylene tere are. Monomer particles such as phthalate, styrene sulfonate, vinyl acetate, methyl styrene, acrylic acid, butyl methacrylate, ethyl methacrylate, 2-ethylhexyl acrylate and N-vinyl caprolactam can be used alone or in a copolymerized manner. .

The content of the monomer particles is preferably 5 to 20 parts by weight, more preferably 8 to 15 parts by weight with respect to 100 parts by weight of the solvent. When the monomer particles are added in less than 5 parts by weight, there is a problem that the resulting polymer particles are less likely to have a chargeability, when exceeding 20 parts by weight, silica nanoparticles as external additives do not sufficiently wrap the surface of the polymer particles There is a problem that the durability and fluidity is lowered.

As described above, in the present invention, the silica nanoparticles are chemically bonded to the surface of the polymer particles produced by the polymerization of the monomer due to the action of the synthesis initiator and the silica nanoparticles, which is a synthesis initiator is a cationic initiator In the case of the cation and the negative charge of the silica nanoparticles is bonded as a mechanism that has a strong ionic bond. On the other hand, when the synthetic initiator is an anionic initiator, a separate anionic monomer may be added together to form a bond between the polymer particles and the silica nanoparticles.

Synthetic initiators used in the present invention include all free radical polymerization initiators capable of triggering non-emulsification polymerization generally used. Synthetic initiators may in principle comprise both peroxides and azo compounds. The peroxide may in principle be a mono- or di-alkali metal salt or an ammonium salt of an inorganic peroxide such as hydrogen peroxide or peroxodisulfate such as peroxodisulfate, for example mono- and di-sodium and -Potassium salts, or ammonium salts, or can be organic peroxides such as alkyl hydroperoxides, for example tert-butyl, p-mentyl and cumyl hydroperoxides, and also dialkyl or diaryl peroxides Such as di-tert-butyl peroxide or dicumyl peroxide. The compounds used are mainly 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile) and 2,2'-azobis (amidinopropyl) Dihydrochloride (AIBA)).

Furthermore, suitable oxidizing agents for the redox initiator system are essentially the peroxides mentioned above. Correspondingly, the reducing agents used are compounds of low sulfur state, such as alkali metal sulfites such as potassium and / or sodium sulfite, alkali metal hydrogen sulfites such as potassium and / or sodium hydrogen sulfite, Alkali metal metabisulfite, for example potassium and / or sodium metabisulfite, formaldehyde-sulfoxylate, for example potassium and / or sodium formaldehyde-sulfoxylate, alkali metal salts, in particular potassium of aliphatic sulfinic acid Salts and / or sodium salts, and alkali metal hydrogen sulfides such as potassium and / or sodium hydrogen sulfide, salts of polyvalent metals such as iron (II) sulfate, iron (II) ammonium sulfate, iron (II) ) Sulfates, endiols such as dihydroxymaleic acid, benzoin and / or ascorbic acid, and reduced saccharides such as sorbose, glucose, fructose and / or Dihydroxyacetone.

In the present invention, 2,2'-azobis (amidinopropyl) dihydrochloride (hereinafter referred to as 'AIBA') is preferably used as a cationic initiator used to prepare positively charged particles. Potassium persulfate (KPS) is used as the anion initiator to be preferably used.

In particular, in the present invention, a bond is formed due to the interaction between the cationic initiator AIBA and the silicon nanoparticles, which is negatively charged at pH 3 or above, and therefore, under the basic environment, the anion of the silicon nanoparticles This is because cations by amine groups contained in AIBA bind to each other to perform chemical ion bonding.

When using KPS which is an anion initiator alone, since the interaction between the said anion initiator and a silicon nanoparticle is weak, it is preferable to use together the anionic monomer mentioned later.

As a result of several experiments, the particle size distribution is good, and the weight ratio of the silica nanoparticles and the synthesis initiator to be preferable for good interaction between the silica nanoparticles and the polymer particles is less than 100: 1, more preferably 1: 1. To 80: 1.

The silica nanoparticles used in the present invention are not particularly limited as long as they can form a stabilizing layer as an external additive of the flowable particles, but preferably LUDOX AM30®, SS-SOL 30F®, Aerosil®, and the like.

The flowable particle composition according to the present invention may further include a functional monomer of any one of a cationic monomer or an anionic monomer so that the prepared particles have a stronger cation or anion.

As the functional monomer used in the present invention, conventional ones are used without particular limitation, and representative cationic monomers include dialkylaminoalkyl acrylates and methacrylates and their quaternary or acid salts (dimethylaminoethyl acrylate methyl tetrachloride, dimethyl Amino ethyl acrylate methyl sulfate quaternary salt, dimethyl amino ethyl acrylate benzyl chloride quaternary salt, dimethyl amino ethyl acrylate sulfate, dimethyl amino ethyl acrylate hydrochloride, dimethyl amino ethyl methacrylate methyl chloride tetrachloride, dimethyl amino ethyl meth relay Tetramethyl sulfate, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfate, dimethylaminoethyl methacrylate hydrochloride, etc.), dialkylaminoalkylacrylamide or methacrylamide and their quaternary salts Or acid salts Acrylamidopropyltrimethylammonium, dimethylaminopropylacrylamidemethylsulfuric acid tetrachloride, dimethylaminopropylacrylamide sulfate, dimethylaminopropylacrylamide hydrochloride, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropylmethacrylamide methyl sulfate Salts, dimethylaminopropylmethacrylamide sulfate, dimethylaminopropylmethacrylamide hydrochloride, diethylaminoethylacrylate, diethylaminoethyl methacrylate, diallyldiethylammonium chloride and diallyldimethylammonium chloride). . Alkyl groups are generally 1-4 alkyl atoms.

Representative anionic monomers include acrylic acid, and salts thereof (including sodium acrylate and ammonium acrylate, etc.), methacrylic acid, and salts thereof (including sodium methacrylate, and ammonium methacrylate, etc.), 2-acrylamido-2- Methylpropanesulfonic acid (AMPS), sodium salt of AMPS, sodium vinyl sulfonate, styrene sulfonate, maleic acid, and salts thereof (including sodium salts and ammonium salts), sulfonate itaconate, sulfopropyl acrylate or methacryl Acid salts or other water soluble forms of these or other polymerizable carboxylic acids or sulfonic acids, sulfomethylated acrylamide, allyl sulfonate, sodium vinyl sulfonate, itaconic acid, acrylamidomethylbutanoic acid, fumaric acid, vinylphosphonic acid, vinylsulfonic acid, allylphosphate Phonic acid, sulfomethylated acrylamide, phosphonomethylated acrylamide and the like.

As a result of many experiments, the content of the functional monomer capable of causing the interaction between the silica nanoparticles and the synthetic initiator is 0.01 to 1 part by weight, more preferably 0.05 to 0.5 part by weight based on 100 parts by weight of water.

In addition, the flowable particle composition according to the present invention may include a charge control agent such as a positive (+) charge control agent or a negative (-) charge control agent, if necessary, and an organic colorant. Or inorganic colorants may be additionally included. The charge control agent may be a positively charged charge control agent such as a nigrosine dye, a triphenylmethane compound, a quaternary ammonium salt compound, a polyamine resin or an imidazole derivative, a salicylic acid metal complex, or a metal (metal ion or metal). Negative charge charge control agents such as azo dyes, oil-soluble dyes containing metals, quaternary ammonium salt compounds, calix arene compounds, boron-containing compounds (boron benzyl complex) or nitroimidazole derivatives; In addition, any charge control agent usable for the flowable particles for the electronic paper image display device may be included. The colorant may be an organic colorant such as nigrosine, methylene blue, quinoline yellow, or rose bengal, titanium oxide, zinc oxide, zinc sulfide, antimony oxide, calcium carbonate, lead white, talc, silica or calcium silicate. , Alumina white, cadmium yellow, cadmium red, cadmium orange, titanium yellow, wire blue, ultramarine blue, cobalt blue, cobalt green, cobalt violet, iron oxide, carbon black, manganese ferrite black, cobalt ferrite black, copper powder or aluminum The same inorganic colorant may be included, in addition, various colorants may be included without limitation. Generally, titanium oxide (TiO ₂ ) is used to coat white particles, and carbon black is used to coat black particles.

Next, the manufacturing method of the flowable particles according to the present invention will be described.

As described above, the method for producing fluid particles according to the present invention includes a mixing step, a polymerization step, and a drying step, and in the mixing step, the flowable particle composition is dispersed in a solvent such as water. As described above, since the synthesis initiator reacts well in a basic environment, a small amount of an acid such as hydrochloric acid and sulfuric acid or an alkaline solution such as ammonia or sodium hydroxide may be added in order to create a basic environment, if necessary. It is preferable to make it into the environment of 13 people. However, since the silicon nanoparticles are basic, a separate acid or base may not be required.

Then, in the polymerization step, the polymerization is preferably carried out by stirring while maintaining a temperature of 40 to 90 ℃, more preferably 60 to 75 ℃, the polymerization step, nitrogen (N ₂ ) or argon (Ar It is preferable to carry out polymerization by an emulsion-free polymerization method by supplying an inert gas such as) to remove dissolved oxygen contained in the solvent, preferably for 15 to 24 hours, more preferably 18 to 22 hours.

Finally, the drying step may be carried out in accordance with the drying step of a conventional fluid particle manufacturing method, preferably using a supercritical process or atmospheric pressure drying of the wet gel after surface hydrophobization and solvent substitution (eg, general Oven drying) may be used. In addition, lyophilization can be performed. This may be used after cooling the mixed aqueous solution containing the polymerized polymer to -100 ° C to -10 ° C to solidify the material, and then lowering the pressure to 4.6torr or less to sublimate the water contained in the freeze powder. .

General details of the manufacturing method of the fluid particles other than the above-mentioned contents can be found in the contents of the application Nos. 10-2006-98634, 10-2007-0003528, and 10-2007-29234 that the applicant has previously filed. Jun.

As described above, according to the flowable particle composition according to the present invention, by synthesizing a synthetic initiator, a silica nanocomposite, etc. as appropriate, it is possible to control the agglomeration of charged particles, to obtain flowable particles excellent in durability and flowability. According to the method for producing flowable particles according to the invention, the silica particles can be uniformly attached to the surface of the polymer particles, it is possible to easily control the particle distribution by adjusting to the optimum pH.

Hereinafter, the preferable experimental example of this invention is described.

Experimental Example 1

In order to examine the influence of the synthetic initiator, an emulsion-free polymer polymerization was carried out while varying the content of the synthetic initiator in a certain amount of monomer.

Specifically, after dispersing 10 g of styrene particles and 2.5 g of silica nanoparticles (LUDOX AM30 (-, anionic)) as a solvent in 100 g of distilled water as a solvent, the temperature was maintained at 65 ° C. using a stirrer and nitrogen. After supplying and sufficiently removing the oxygen of the distilled water, and reacted for 21 hours while 30 minutes after the start of the reaction while changing the AIBA to the input amount shown in Table 1 as an initiator to synthesize the polystyrene (polystyrene) nanoparticles. In contrast, the change in particle size, reactivity and content of silica attached to the resulting polymer particles are as described in Table 1.

TABLE 1

Experiment number Distilled water (g) Styrene (g) AIBA (g) LUDOX AM30 (-) Response time (hours) Responsive Attached Silica Content (%) Particle size (nm) Content (g) Input time 1-1  100  10 0.05  2.5  30 minutes  21 O 2.86 227 1-2 0.1 O 25.42 780.3 1-3 0.15 O 1.24 399.4

As shown in Table 1, in all three experiments, it was possible to obtain flowable particles in which silyl particles were coated on the surface of the polymer particles, the best of which was the second experiment (AIBA 0.1 g). It was.

Experimental Example 2

Next, in order to examine the effect of the injected silica nanoparticles, the remaining experimental conditions were the same as in Experimental Example 1, the amount of the synthetic initiator (AIBA) was fixed, and the amount of the silica nanoparticles (LUDOX AM30 (-)) The polymerization was carried out while varying. The results thereof are as described in the following <Table 2> and FIG. 3 is an SEM photograph of the flowable particles formed by experiment numbers 2-1, 2-2, and 2-3 from the left side, respectively.

TABLE 2

Experiment number Distilled water (g) Styrene (g) AIBA (g) LUDOX AM30 (-) Reaction time (hours) Responsive Attached Silica Content (%) Particle size (nm) Content (g) Input time 2-1   100   10   0.05 0.62   30 minutes   21 X X - 2-2 1.25 O 27.80 531 2-3 2.5 O 2.86 227 2-4 5 X X X 2-5 10 X X X

Here, as shown in Figure 3, when the amount of the silica nanoparticles is added too little, no particle formation. In other words, the silica nanoparticles act as an emulsifier (emulsion) in the emulsion-free polymerization. If the amount of the added silica nanoparticles is too small, the particle dispersion stability is deteriorated, and thus it is considered that the polymer particles are not formed. In addition, as shown in Table 2, when the amount of the silica nanoparticles added was too large (synthetic initiator: silica nanoparticles = 1: 100 or more), silica was not formed on the surface of the polymer. That is, no reaction occurred. Thus, rather than increasing the amount of silica nanoparticles, it is determined that the content ratio of the synthesis initiator and the silica nanoparticles within a certain range affects the reaction more.

Experimental Example 3-1

First, in order to increase the interaction between the polymer particles and the silica nanoparticles, except that silica nanoparticles (LUDOX SM30 (pH = 10)) having higher zeta potential than Experimental Examples 1 and 2 were applied. And the experiment was carried out under the same conditions as in Experimental Example 1. The results are shown in Table 3 below.

TABLE 3

Experiment number Distilled water (g) Styrene (g) AIBA (g) LUDOX SM30 (-) Reaction time (hours) Responsive Attached Silica Content (%) Particle Size (nm)  Zeta Potential (mV) Content (g) Input time 3-1  100  10 0.05  2.5  30 minutes  21 O 3.4 480.4 -55.81 3-2 0.1 X X X X 3-3 0.15 X X X X

As shown in Table 3, unlike Experimental Example 1, in Experimental Example 3-1, the reaction did not occur with the increase of the synthesis initiator (the relative amount of the silica nanoparticles decreased).

Experimental Example 3-2

Thus, Experimental Example 3- by adding a base solution to the flowable particle composition so that the pH of the solvent-styrene-synthetic initiator dispersion, which is a reaction medium, is equal to the pH of the silica nanoparticle LUDOX SM30 solution (pH = 10). The same experiment as in Experiment 3-1 was carried out while varying the input amount of the silicon nanoparticles to the content of the synthetic initiator (AIBA 0.1 g) that did not react in 1. The results are shown in <Table 4>.

TABLE 4

Experiment number Distilled water (g) Styrene (g) AIBA (g) LUDOX SM30 (-) Response time (hours) pH Responsive Attached Silica Content (%) Particle Size (nm) Zeta Potential (mV) Content (g) Input time 3-4  100  10  0.1 1.25  0 min  21  10 O 0.7 524 -30.70 3-5 2.5 O 11.5 576.9 -29.15 3-6 5.0 O 9.9 429 -34.48

As shown in Table 4, the experiment was carried out with a pH of the reaction medium of 10. As a result, the reaction proceeded with the amount of the synthetic initiator that was not reacted in Experiment 3-1. In addition, it can be seen that the larger the content of silica attached to the polymer particles in the experiment, the smaller the zeta potential value.

Experimental Example 3-3

In order to examine the effect of the pH of the flowable particle composition in more detail, the same experiment as in Experimental Example 3-1 was performed while fixing the remaining conditions and changing the pH. The results are as shown in Table 5 and FIG. 4 below. 4 is an SEM photograph of the flowable particles formed by Experiment Nos. 3-7, 3-8, and 3-9 from the left side, respectively.

TABLE 5

Experiment number Distilled water (g) Styrene (g) AIBA (g) LUDOX SM30 (-) Response time (hours) pH Responsive Attached Silica Content (%) Particle Size (nm)  Zeta Potential (mV) Content (g) Input time 3-7  100  10  0.1  2.5  0 min  21 10 O 0.7 524 -29.15 3-8 7 O 11.5 576.9 -54.41 3-9 4 O 9.9 429 -53.08

As shown in Table 5 and FIG. 4, all three reactions proceeded, but the lower the pH value, the larger the particle size distribution. Thus, it was found that the state of the most suitable composition was a basic environment. As a result of other experiments, the pH at which the excellent experimental results were obtained was in the range of 8 to 13.

Experimental Example 4

Next, experiments were performed using an anionic initiator (KPS) to produce negative charge particles. The other conditions were the same as those of Experimental Example 1, but the synthetic initiator was used as an anionic initiator KPS, a cationic SS-SOL 30A as silicon nanoparticles, and the pH was changed to find the most suitable pH environment. The results are as described in Table 6 below.

TABLE 6

Experiment number Distilled water (g) Styrene (g) KPS (g) SS-SOL 30A (+) Response time (hours) pH Responsive Particle size (nm) Content (g) Input time 4-1  100  10  0.1  2.5  0 min  21 2.3 O 795.1 4-2 7 O 410.1 4-3 10 O 388.7

As can be seen from Table 6, even when an anionic initiator was used, it was found that the reactivity of the silica and the polymer particles was good in a basic environment at pH 10.

Experimental Example 5

Next, with the styrene monomer, the amount of 4-styrenesulfonic acid sodium salt as an anionic monomer for imparting a stronger negative charge to the polymer particles is changed, the same conditions as in Experimental Example 4 The experiment (copolymerization) of was performed. The results are as described in Table 7 below.

TABLE 7

Experiment number Distilled water (g) Styrene (g) 4-styrene sodium sulfonate (g) KPS (g) SS-SOL 30A (+) pH Response time (hours) Responsive Particle size (nm) Content (g) Input time 7-1  100  10 0.05  0.1  2.5  0 min 7  21 O 206.7 7-2 0.1 7 O 163.1 7-3 0.1 10 O 203.8 7-4 One 7 X X

As can be seen from Table 7, when the anionic monomer was added 10% by weight based on 100% by weight of styrene, the reaction did not proceed even though the silica nanoparticles were present. In addition, the electrostatic interaction of the silica nanoparticles and the polymer particles was found to be good at pH 10 conditions.

Although preferred embodiments of the present invention have been described above, the present invention may use various changes and modifications and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

1 is a cross-sectional view showing a cell structure of a collision charging type electronic paper image display apparatus according to the prior art;

Figure 2 is a cross-sectional view showing the particles used in the electronic paper image display device according to the prior art

3 is a SEM photograph of the flowable particles formed by Experimental Example 2 of the present invention.

4 is a SEM photograph of the flowable particles formed by Experimental Example 3-3 of the present invention.

<Description of Signs of Major Parts of Drawing>

1: polymer particle 2: charge control agent

3: pigment / dye 4: external additive

10: upper substrate 20: lower substrate

30: upper electrode 40: lower electrode

50: bulkhead 60,70: charged particles

Claims (14)

5-20 weight part of monomer particles, 0.01-0.5 weight part of synthesis initiators, and 0.5-10 weight part of silica nanoparticles are contained with respect to 100 weight part of solvents, The fluid particle composition characterized by the above-mentioned. The method of claim 1, The flowable particle composition further comprises a functional monomer of any one of a cationic monomer and an anionic monomer, wherein the functional monomer is 0.01 to 1 part by weight based on 100 parts by weight of the solvent. The method of claim 1, The monomer particles are styrene, methyl methacrylate, ethylene terephthalate, styrene sulfonate, vinyl acetate, methyl styrene, acrylic acid, butyl methacrylate, ethyl methacrylate, 2-ethylhexyl acrylate, N-vinyl caprolactam Flowable particle composition, characterized in that at least one of. The method according to any one of claims 1 to 3, The flowable particle composition further comprises at least one of a charge control agent or a colorant. The method of claim 2, The functional monomer is a flowable particle composition, characterized in that the cationic monomer. The method according to claim 1 or 5, The synthetic initiator is a flowable particle composition, characterized in that the cationic initiator. The method of claim 6, The cationic initiator is 2,2'-azobis (2-methylpropionamidine) dihydrochloride (2,2'-azobis (2-methylpropionamidine) dihydrochloride) characterized in that the fluid particle composition. The method of claim 2, The functional monomer is an anionic monomer, The synthetic initiator is a flowable particle composition, characterized in that the anionic initiator. The method of claim 8, The anionic initiator is potassium persulfate (potassium persulfate; KPS), characterized in that the flowable particle composition. The method according to any one of claims 1 to 3, The flowable particle composition is pH 8 to 13, characterized in that the flowable particle composition. A mixing step of mixing the flowable particle composition including 5 to 20 parts by weight of the monomer particles, 0.01 to 0.5 parts by weight of the synthesis initiator, and 0.5 to 10 parts by weight of the silica nanoparticle composite; A polymerization step of polymerizing the mixed solution at a temperature of 40 to 90 ° C. for 15 to 24 hours; Method for producing a fluid particle, characterized in that it comprises a drying step of drying the solution. The method of claim 11, The mixing step further comprises a pH adjusting step of adjusting the pH of the flowable particle composition to 8 to 13 by adding an acid or alkaline solution. The method of claim 12, The polymerization step is supplying an inert gas, fluidized particles manufacturing method characterized in that it further comprises an oxygen removal step of removing the dissolved oxygen contained in the solvent. The method of claim 11, The flowable particle composition is a flowable particle composition according to any one of claims 2, 3, 5, 8 or 9, characterized in that the flowable particle composition.

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