KR101098536B1 - METHOD OF MANUFACURING FLUENT PARTICLE USING Ti(Obu)4 - Google Patents

Abstract

The present invention relates to a method for producing flowable particles using tetraolmalbutyl titanate. The method for producing flowable particles using tetraolmalbutyl titanate according to the present invention includes monomers 5 to 20 based on a solvent and 100 parts by weight of a solvent. A core forming step of forming a core by mixing parts by weight, 0.1 to 3 parts by weight of a polymerization initiator, and 0.5 to 15 parts by weight of a dispersion stabilizer; A dissolution step of dissolving tetranomal butyl titanate in ethanol (EtOH); A first mixing step of preparing a first mixed solution by mixing silica in the core with 0.7 to 3 parts by weight based on 100 parts by weight of the solvent; A second mixing step of preparing the second mixed solution by mixing the tetranomal butyl titanate in the first mixed solution with respect to 100 parts by weight of the solvent and the ethanol, 0.5 to 2 parts by weight; A polymerization step of polymerizing the second mixed solution at a temperature of 40 to 90 ° C. for 30 to 50 hours to produce fluid particles; It comprises a; drying step of drying the flowable particles.

According to the manufacturing method of the fluid particle | grains using the tetranomal butyl titanate which concerns on this invention, reflectance improves significantly by using tetranomal butyl titanate, and dispersion stability of a particle can be improved by using a dispersion stabilizer, and a particle It has the advantage of controlling the occurrence of hepatic aggregation, and by dispersion polymerization, it has the advantage of improving the adsorption property with silica and tetranomal butyl titanate, easily forming the bonded particles, and the aggregation of charged particles due to the silane surface treatment. The phenomenon can be solved, there is an advantage that can lower the initial drive voltage of the fluid particles.

Fluid particles, dispersion polymerization, electronic paper, initiator, silica, dispersion stabilizer, durability, reflectance

Description

Method for producing fluid particles using tetranomal butyl titanate {METHOD OF MANUFACURING FLUENT PARTICLE USING Ti (Obu) 4}

The present invention relates to a method for producing fluid particles using tetranomal butyl titanate, and more particularly, by producing polymerized fluid particles in which polymer dioxide (TiO ₂ ) and silica (SiO ₂ ) are bonded to the polymer by dispersion polymerization. The present invention relates to a method for producing flowable particles using tetranomal butyl titanate, which improves reflectance, controls aggregation between charged particles, and provides flowable particles having low initial driving voltage and excellent durability and fluidity.

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 conventional technologies are considered to be a technology that can be used for an inexpensive image display device because of the advantages of having a wider viewing angle closer to that of a normal printed matter, a smaller power consumption, and a memory function than LCDs, and thus making it possible to use an image display device for a mobile terminal. 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 moved 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, by chemically bonding titanium dioxide (TiO ₂ ) and silica (SiO ₂ ) to the monomer by one dispersion polymerization, a separate process is not required. The economic effect is excellent, and because of the chemical bonding unlike the prior art, to provide a method for producing flowable particles excellent in durability and excellent fluidity of the bond.

In addition, by using tetraol-malbutyl titanate, the reflectance is greatly improved, the particle pH can be easily controlled by adjusting to the optimum pH, and by using a dispersion stabilizer, the dispersion stability of particles is increased, and the aggregation between particles is generated. It is to provide a method for producing flowable particles that can control the.

In addition, the dispersion polymerization, compared with the emulsion polymerization, the adsorption of silica and tetranoyl butyl titanate is improved, the binding particle formation is easy, the silane surface treatment can solve the agglomeration between the charged particles, flowable particles It is to provide a method for producing a flowable particles that can lower the initial drive voltage of.

In order to achieve the above object, the method for producing fluid particles using the tetranomal butyl titanate of the present invention includes 5 to 20 parts by weight of monomer, 0.1 to 3 parts by weight of polymerization initiator, and dispersion with respect to 100 parts by weight of a solvent and a solvent. A core forming step of forming a core by mixing 0.5 to 15 parts by weight of a stabilizer; A dissolution step of dissolving tetranomal butyl titanate in ethanol (EtOH); A first mixing step of preparing a first mixed solution by mixing silica in the core with 0.7 to 3 parts by weight based on 100 parts by weight of the solvent; A second mixing step of preparing the second mixed solution by mixing the tetranomal butyl titanate in the first mixed solution with respect to 100 parts by weight of the solvent and the ethanol, 0.5 to 2 parts by weight; A polymerization step of polymerizing the second mixed solution at a temperature of 40 to 90 ° C. for 30 to 50 hours to produce fluid particles; It characterized in that it comprises a; drying step of drying the flowable particles.

In addition, the surface treatment step of treating the surface of the flowable particles with silane; In the first mixing step or the second mixing step, pH adjustment step of adjusting the pH of the hydrogen ion index (pH) to 8 to 13 by adding an acid or alkaline solution to the first mixture solution or the second mixture solution; It further comprises.

Further, in the core forming step, the monomer is styrene, methyl methacrylate, ethylene terephthalate, styrene sulfonate, vinyl acetate, methyl styrene, acrylic acid, butyl methacrylate, ethyl methacrylate, 2-ethylhexyl acrylate , N-vinyl caprolactam is characterized in that at least one.

In the core forming step, the polymerization initiator is 2,2'-azobis (isobutyramidine) hydrochloride (2,2'-azobis (isobutyramidine) hydrochloride), characterized in that in the core forming step, Dispersion stabilizer is characterized in that the poly vinyl pyrrolidone (Poly Vinyl pyrrolidone).

Further, in the core forming step, the solvent comprises water and ethanol, and in the surface treatment step, the silane is tridecafluoro-1,1,2,2-tetrahydrooctyl triethoxy Silane (tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane) or 3,3,3-trifluoropropyltrimethoxysilane (3,3,3-trifluoropropryl methoxysilane) or ethoxytrimethylsilane (ethoxy

trimethylsilane) is characterized in that at least one.

In addition, in the surface treatment step, the hydrogen ion index (pH) is maintained at 8 to 13, the silane is characterized in that it comprises 5 to 10 parts by weight based on 100 parts by weight of the solvent.

According to the method for preparing flowable particles using tetranomal butyl titanate of the present invention, chemically bonding titanium dioxide (TiO ₂ ) and silica (SiO ₂ ) to a monomer by one dispersion polymerization does not require a separate process. It does not have an economic effect, and because of the conventional chemical bonding, unlike the conventional, there is an advantage of excellent durability and excellent fluidity.

In addition, by using tetranomal butyl titanate, the reflectance is greatly improved, and the particle distribution can be easily controlled by adjusting to an optimum pH.

In addition, by using the dispersion stabilizer, it is possible to increase the dispersion stability of the particles, there is an advantage that can control the generation of aggregation between particles.

In addition, the dispersion polymerization, compared with the emulsion polymerization, has the advantage that the adsorption with silica, tetranomal butyl titanate is improved, and the binding particle formation is easy.

In addition, due to the silane surface treatment it is possible to solve the aggregation phenomenon between the charged particles, there is an advantage that can lower the initial drive voltage of the fluid particles.

EMBODIMENT OF THE INVENTION Hereinafter, the manufacturing method of the fluid particle | grains using the tetranomal butyl titanate which concerns on this invention is described in detail with reference to attached drawing. The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

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 suggested that a method of increasing the yield by reducing the number of process steps and economical efficiency in which fluid particles can be obtained by performing polymerized dispersion is obtained by polymerizing polymer particles alone. It became.

According to the dispersion polymerization according to the present invention, the surfactant does not enter during the polymerization process, but includes a polymerization initiator, a dispersion stabilizer 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 polymerization initiator and the silica (SiO ₂ ) and titanium dioxide (TiO ₂ ) anions, a strong chemical bond between the external additive and the polymer particles is already generated at the time of polymer particle generation. there was.

According to the above production method, the silica particles and the titanium dioxide particles 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.

The flowable particle composition according to the present invention comprises a solvent, a monomer, a polymerization initiator, a dispersion stabilizer, tetranomal butyl titanate (Ti (Obu) ₄ ), and silica.

It is preferable to use the solvent which mixed water and ethanol. In the case where water and ethanol are not mixed, dispersion polymerization is not performed smoothly, and therefore, a bond between tetranomal butyl titanate (Ti (Obu) ₄ ) and silica is difficult to form normally.

The monomer is not particularly limited as long as it can be dispersed and polymerized, but methyl methacrylate, ethylene terephthalate, styrene sulfonate, vinyl acetate, methyl styrene, acrylic acid, butyl methacrylate, ethyl methacrylate, 2-ethylhexyl Monomer particles, such as acrylate and N-vinyl caprolactam, can be used alone or in a copolymerized manner, and preferably styrene is most effective.

The content of the monomer 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 is added in less than 5 parts by weight, there is a problem that the resulting polymer particles are less likely to be charged, and when it exceeds 20 parts by weight, silica and titanium dioxide (TiO ₂ ) as external additives sufficiently cover the surface of the polymer particles. There is a problem that the durability and fluidity is deteriorated due to not wrapped.

As described above, in the present invention, due to the interaction between the polymerization initiator and silica and titanium dioxide (TiO ₂ ), silica and titanium dioxide (TiO ₂ ) are chemically bonded to the surface of the polymer particles produced through the polymerization of the monomer. This is accomplished by a mechanism whereby the synthesis initiator is a cation, and the negative charge of silica and titanium dioxide (TiO ₂ ) is combined to have strong ionic bonds.

Copolymerization initiators used herein include all free radical polymerization initiators capable of triggering the dispersion polymerization generally used. The polymerization initiator may in principle comprise both peroxides and azo compounds, said peroxides being in principle inorganic peroxides such as hydrogen peroxide or peroxodisulfate such as mono- or di-alkali metals of peroxodisulfate Salts or ammonium salts, examples of which are mono- and di-sodium and -potassium salts, or ammonium salts, or may be organic peroxides such as alkyl hydroperoxides, for example tert-butyl, p- Menthyl and cumyl hydroperoxide, 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). Preferably, 2,2'-azobis (isobutyramidine) hydrochloride (2,2'-azobis (isobutyramidine) hydrochloride) (hereinafter referred to as 'AIBA') is most efficiently used as a polymerization initiator. AIBA has the following structure.

In particular, in the present invention, a bond is formed due to the interaction between the cation initiator AIBA and silica and titanium dioxide (TiO ₂ ), which is a basic environment because the silica particles have a negative charge at a pH of 3 or higher. This is because the anion of the silica particles and the cation by the amine group contained in the AIBA is bonded to perform the chemical ion bonding.

The polymerization initiator preferably contains 0.1 to 3 parts by weight, more preferably 1 to 2 parts by weight based on 100 parts by weight of the solvent. If the polymerization initiator is less than 0.1 part by weight, the interaction between silica and titanium dioxide (TiO ₂ ) is difficult, and no bond is formed. When the polymerization initiator is more than 3 parts by weight, the cation is excessive, so that the bonding strength is weak and economical inferior. there is a problem.

In addition, since the present invention forms the particles by dispersion polymerization, in order to achieve a dispersion polymerization reaction, a dispersion stabilizer is included. As a dispersion stabilizer, various materials can be used, but it is effective to use poly vinyl pyrrolidone (hereinafter, referred to as 'PVP') most preferably after several experiments. PVP increases the dispersion stability of the particles.

Herein, the dispersion stabilizer preferably contains 0.5 to 15 parts by weight, and more preferably 5 to 8 parts by weight based on 100 parts by weight of the solvent. When the dispersion stabilizer is less than 0.5 parts by weight, the dispersion of the monomer is not good, the dispersion polymerization reaction is not performed smoothly, there is a problem that the size of the flowable particles are uneven, the possibility of aggregation between particles increases.

3 is an experimental result of whether PVP affects the aggregation between particles during the formation of flowable particles. When PVP is present (a), PVP is present and the hydrogen ion index (pH) is adjusted to 10 (b), PVP In the case of (c) there was no SEM to compare the aggregation of the particles. As shown in FIG. 3, in the case of (a) and (b) with PVP, the coagulation of particles was significantly removed as compared with (c). Showed less aggregation. This proved that PVP had the most excellent effect on eliminating agglomeration of particles.

In addition, Figure 4 is an experimental result of how the PVP and pH affect the particle size and evenness, Figure 4a is a core particle in the presence of PVP, Figure 4b is a core particle in the absence of PVP, Figure 4c is Flowable Particles with PVP, FIG. 4D is a flowable particle with PVP and pH 10, FIG. 4E is a graph of the size and level of flowable particles with no PVP and pH 10. FIG. As shown in FIG. 4, when PVP is present, the particles appear to be evenly uniform, and when the pH is maintained at 10, the size of the particles is also small and even. Therefore, in the case of FIG. 4D where PVP is present and the pH is maintained at 10, it is proved by the experimental results that the performance shows the best flowable particles, so that the performance of the best flowable particles is ensured in the case of the scope of the present invention. Able to know.

In addition, Figure 5 is a graph showing the results of the experiment according to the presence or absence of PVP and pH control by infrared spectroscopy (hereinafter referred to as IR). Again in FIG. 3 (a), (b) , (c) and that a new peak appeared when viewed as a strong peak appears in the result, 1600 ~ 2000cm ^-1 experiment under the conditions, as Ti-O-Si bonds are formed Since it is estimated, (b) also falls within the scope of the present invention, it can be seen that the bond is best formed.

6 is a graph measuring the inorganic content according to the presence or absence of PVP under the same conditions as (b) and (c) of FIG. 5, and (b) also falling within the scope of the present invention showed the highest inorganic content. The results show that the most bond is formed.

The flowable particle composition of the present invention includes tetraolmalbutyl titanate (Ti (Obu) ₄ ), which is converted into a form of titanium dioxide (TiO ₂ ) in the process of mixing with the monomer, thereby binding to the monomer, and the flowable particle It is effective to greatly increase the reflectance of. This reflectivity increase effect can be seen through the reflectance comparison test results in Table 1 below.

TABLE 1

Reflectance (%) White board 100.0 Polymer 77.5 Polymer-SiO ₂ 85.3 Polymer-SiO ₂ , TiO ₂ 92.0 to 98.0

In addition, the silica is included to bond with the monomer as an external additive of the flowable particles. The silica particles are not particularly limited as long as they can form a stabilization layer, but may include LUDOX AM30®, SS-SOL 30F®, Aerosil®, and the like, most preferably LUDOX SM30®.

In order to stabilize the bonding between the monomer and the silica and titanium dioxide (TiO ₂ ), the hydrogen ion index (pH) is preferably maintained at 8 to 13, and most preferably at 10 to 11 is effective. When the hydrogen ion index (pH) is less than 8 or greater than 13, the coupling reaction between the monomer and silica and titanium dioxide (TiO ₂ ) does not occur well, and there is a problem in that stable fluid particles cannot be prepared.

Several experiments have shown that the particle size distribution is good and the weight ratio of tetra (n) (Obu) ₄ to silica is desirable for good interaction between silica and titanium dioxide and monomers. : 3, most preferably 1: 1.4 to 1: 1.6. When tetraol-malbutyl titanate (Ti (Obu) ₄ ) is included in more than the weight ratio, there is a problem in which a reverse reaction occurs and is converted into a monomer. When silica is included in more than the weight ratio, monomer particles are present in a broken state or more silica content. There is a problem in that the hollow particles of the fluid form empty form.

Experimental results on the effect of the content ratio of silica and tetranomal butyl titanate on the particles are shown in Figs.

As shown in FIG. 7, as the content of tetranomal butyl titanate increases, it was found that agglomerated particles (TiO ₂ ) exist around the bound flowable particles, which means that titanium (Ti) is silica (SiO _2). As a phenomenon that appears because the reaction rate is faster than), it can be seen that the coagulation phenomenon is the least when maintaining the content ratio of silica and tetranomal butyl titanate of the present invention as described above.

In addition, the experimental results of FIG. 8 in which only PVP is present under the same conditions as shown in FIG. 7 form more stable particles than FIG. 7, and it can be confirmed that once more PVP is present, more stable particles can be formed. there was.

As shown in FIG. 9, when the content ratio of tetranomal butyl titanate and silica is less than 1: 0.7 (c), a reverse reaction occurs and particle separation is impossible, and the content ratio of tetranomal butyl titanate and silica is greater than 1: 3. When (a) the hollow particles of the flow is empty, when the content ratio is 1: 1.5 (b) of the range of the present invention, the flowable particles are combined monomers and silica and tetranomal butyl titanate.

Figure 10a is a core particle before the silica and tetra-butyl butyl titanate is mixed, Figure 10b is a graph of Figure 9 (a), Figure 10c is a graph of Figure 9 (b), compared to this, also the present invention In (b) it can be seen that the size of the particles is small, forming a uniform particle distribution.

The (a), (b) of Figure 11 is the Figure 3 in a graph compared by infrared spectroscopy (hereinafter referred to as Infrared Spectroscopy, hereinafter IR), styrene also peak at 900 ~ 1200cm ^-1 in the present inventions (b) ( In addition to the peak), a Si-O-Si peak was generated, and two Si-OH peaks were formed at 600 cm ⁻¹ or less, indicating that the monomer, silica, and tetranomal butyl titanate were combined.

Therefore, the tetranomal butyl titanate (Ti (Obu) ₄ ) preferably contains 0.5 to 2 parts by weight based on 100 parts by weight of the solvent and ethanol, and the silica is 0.7 to 3 parts by weight based on 100 parts by weight of the solvent. It is preferable to include a part.

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.

Next, the manufacturing method of the flowable particles according to the present invention will be described. The method for producing the flowable particles is the same as the description of the flowable particle composition, and will be described below mainly on the characteristics of the production method.

As shown in Figure 12, the manufacturing method of the flowable particles according to the present invention core forming step (S10), dissolution step (S20), the first mixing step (S30), the second mixing step (S40), the polymerization stage (S50), drying step (S60), surface treatment step (S70), pH adjustment step (S31, S41) is made to include.

The core forming step (S10) is a step of forming a core by mixing 5 to 20 parts by weight of monomer and 0.1 to 3 parts by weight of a polymerization initiator with respect to 100 parts by weight of a solvent and a solvent. The core particles are formed by mixing about 15 to 24 hours, including the type and content of monomers and polymerization initiators as discussed in the fluid particle composition. Core particles formed by the core forming step (S10) is as shown in FIG.

Dissolution step (S20) is a step of dissolving tetranol butyl titanate in ethanol (EtOH). This is a step for controlling the reaction rate of tetranomal butyl titanate and silica, and after dissolving tetranomal butyl titanate in ethanol proceeds to the following mixing process.

The first mixing step (S30) is a step of preparing a first mixed solution by mixing silica in the core 0.7 to 3 parts by weight based on 100 parts by weight of the solvent.

In addition, the second mixing step (S40) is a step of preparing a second mixed solution by mixing 0.5 to 2 parts by weight of the tetranomal butyl titanate, 100 parts by weight of the solvent and the ethanol in the first mixture solution to be. Tetranomal butyl titanate has an effect of significantly improving the reflectance of the flowable particles.

As shown in FIG. 14, when only tetranomal butyl titanate is mixed without adding silica (a), when silica is mixed first and then tetranomal butyl titanate is mixed (b), tetranomal butyl titanate is added. In the case of mixing first and then mixing silica (c), the SEM image shows that in the case of (a), reverse reaction occurs and is converted into monomer, so no particles are formed, and in case of (c), separation is impossible. Since the particles are not formed, the flowable particles are normally formed only when the silica is mixed as in the present invention (b). This data demonstrates that the mixing order also has an important effect on particle formation.

In addition, Figure 15a is a graph of the size of the core particles through the core forming step (S10), Figure 15b is a particle size graph for Figure 14 (a), Figure 15c is a particle size graph for Figure 14 (b) In addition, it can be seen that (b) of the present invention even more (a) the size of the particles, silica and titanium dioxide is combined without forming a particle.

pH adjustment step (S31, S41) is the first mixing step or the second mixing step, by adding an acid or alkaline solution to the first mixture solution or the second mixture solution to the hydrogen ion index (pH) 8 to Step 13 is adjusted. As described above, since the polymerization 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 is added to make a basic environment as necessary. It is desirable to make a phosphorus environment. Most preferably it is effective that the pH is 10-11. When the hydrogen ion index (pH) is less than 8 or more than 13, the coupling reaction between the monomer and silica and titanium dioxide (TiO ₂ ) does not occur well, and thus there is a problem in that stable fluid particles cannot be prepared. However, since silica particles are basic, a separate acid or base may not be required.

The polymerization step (S50) is a step of polymerizing the second mixed solution at a temperature of 40 to 90 ° C. for 30 to 50 hours to prepare flowable particles. The polymerization temperature is preferably maintained at a temperature of 40 to 90 ° C, more preferably 60 to 75 ° C. The polymerization step (S50) is to perform the polymerization while stirring, supplying an inert gas such as nitrogen (N ₂ ) or argon (Ar), while removing the dissolved oxygen contained in the solvent, preferably 15 to 24 hours More preferably, the polymerization by the non-emulsification polymerization method is performed for 18 to 22 hours. If the polymerization time is less than 15 hours or more than 24 hours, the polymerization reaction is not smoothly performed, there is a problem that a stable fluid particles can not be produced.

Drying step (S60) is a step of drying the flowable particles. This may be carried out in accordance with the drying step of the conventional method for producing a fluid particle, preferably dry using a supercritical process or atmospheric pressure drying of the wet gel subjected to surface hydrophobization and solvent substitution (for example, normal oven drying), etc. Can 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. . The flowable particles produced through the drying step S60 have a structure as shown in FIG. 3.

Surface treatment step (S70) is a step of treating the surface of the flowable particles with silane. This is a process of hydrophobizing the surface of the flowable particles in order to prevent agglomeration between particles due to the presence of OH groups at the ends of the prepared flowable particles. As a surface treatment method, the OH group of the fluid particles is removed by causing hydrolysis and condensation using salane.

Here, the silane may be any kind of silane, but tridecafluoro

-1,1,2,2-tetrahydrooctyltriethoxysilane (tridecafluoro-1,1,2,2-tetrahydro

octyltriethoxysilane, CF ₃ -TES) or 3,3,3-trifluoropropyltrimethoxysilane

(3,3,3-trifluoropropryl methoxysilane, CF ₃ -TMS) or ethoxytrimethylsilane

The use of at least one of (ethoxytrimethylsilane, ETMS) is the most effective to suppress the flocculation between the flowable particles after several experiments.

_{<CF 3 -TES><CF 3} -TMS><ETMS>

16 and Table 2 are the results of Experiment 1, 17 and Table 3 are the results of Experiment 2, except that only the weight ratio of silica and tetranomalbutyl titanate was changed, and the results of experiments on silane treatment were performed. 2, as shown in Table 3, the silane-treated particles noticeably lower the initial driving voltage than the silane-treated particles, among which CF ₃ -TES, CF ₃ -TMS treatment is more initial than the ETMS It can be lowered.

TABLE 2

Initial drive voltage (V) No silane treatment 160 ETMS processing 130 CF ₃ -TES treatment 130

TABLE 3

Initial drive voltage (V) No silane treatment 130 ETMS processing 120 CF ₃ -TES treatment 100 CF ₃ -TMS processing 100

In the surface treatment step (S70), the silane preferably contains 5 to 10 parts by weight, and most preferably 6.5 to 8 parts by weight based on 100 parts by weight of the solvent. If it is less than 5 parts by weight, the effect of preventing aggregation between the fluid particles is insignificant, and if it exceeds 10 parts by weight, there is a problem that the initial driving voltage of the fluid particles is increased.

18 and Table 4 are experimental results of measuring the change in the initial driving voltage according to the content of the silane, as shown in Figure 18 and Table 4, when the silane is included in 3 parts by weight with respect to 100 parts by weight of the solvent When the drive voltage 130V, 7 parts by weight is included, it can be seen that the initial drive voltage can be lowered as much as possible by maintaining the content of silane corresponding to the scope of the present invention to the initial drive voltage 110V.

TABLE 4

Initial drive voltage (V) ETMS treatment (3% by weight) 130 ETMS treatment (7% by weight) 110

In addition, the hydrogen ion index (pH) in the surface treatment step (S70) is preferably maintained at 8 to 13, most preferably at 10 to 11 is effective. If the hydrogen ion index (pH) is less than 8 or exceeds 13, there is a problem that the initial drive voltage increases.

19 and Table 5 are experimental results of measuring the change in the initial driving voltage according to the hydrogen ion index (pH), since the effect of the silane treatment varies depending on the hydrogen ion index (pH), the optimal hydrogen ion index (pH) It is an experiment to prove that it should be maintained. As shown in FIG. 19 and Table 5, it can be seen that the initial drive voltage is the lowest when the hydrogen ion index (pH) is maintained at 10, which is the range of the present invention, and silane treatment.

TABLE 5

Initial drive voltage (V) no pH adjustment 130 pH 10 100 pH 2 110

The order of the above steps is not absolute and can be changed in some cases, and it is also within the scope of the present invention.

Although preferred embodiments of the present invention have been described above, the present invention may use various changes, 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

Figure 3 is a TEM photograph of the particles produced according to the PVP addition and pH control

4 is a graph showing the particle size distribution according to FIG.

5 is a graph analyzing the particles according to FIG. 3 according to an infrared spectroscopy method

6 is a graph measuring the inorganic content according to the temperature of the particles according to FIG.

7 is a TEM photograph taken of particles according to the content ratio of tetranomal butyl titanate and silica

FIG. 8 is a TEM photograph of particles (with PVP) according to the content ratio of tetranomal butyl titanate and silica

9 is a TEM photograph of the particles according to the content ratio of tetranomal butyl titanate and silica

10 is a graph showing the size distribution of particles according to the content ratio of tetranomal butyl titanate and silica

11 is an infrared spectroscopy (IR) analysis graph of particles according to the content ratio of tetranomal butyl titanate and silica

12 is a flow chart sequentially showing a method for producing flowable particles using tetranomal butyl titanate according to the present invention

Figure 13 is a TEM photograph of the core particles formed by the core forming step (S10) of the present invention

FIG. 14 is a TEM photograph of particles produced according to a mixing sequence of silica and tetranomal butyl titanate. FIG.

15 is a graph showing particle size distribution according to FIG. 14.

16 is a graph showing the driving voltage (V) of the particles according to the silane treatment

17 is a graph showing the driving voltage (V) of the particles according to the silane treatment

18 is a graph showing the driving voltage (V) of the particles according to the content of silane

19 is a graph showing the driving voltage (V) of the particles according to the hydrogen ion index (pH) of the silane

<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 (9)

A core forming step of mixing 5 to 20 parts by weight of the monomer, 0.1 to 3 parts by weight of the polymerization initiator, and 0.5 to 15 parts by weight of the dispersion stabilizer based on the solvent and 100 parts by weight of the solvent until the core is formed; A dissolution step of dissolving tetranomal butyl titanate in ethanol (EtOH); A first mixing step of preparing a first mixed solution by mixing silica in the core with 0.7 to 3 parts by weight based on 100 parts by weight of the solvent; A second mixing step of preparing the second mixed solution by mixing the tetranomal butyl titanate in the first mixed solution with respect to 100 parts by weight of the solvent and the ethanol, 0.5 to 2 parts by weight; A polymerization step of polymerizing the second mixed solution at a temperature of 40 to 90 ° C. for 30 to 50 hours to produce fluid particles; And It includes; drying step of drying the flowable particles, In the core forming step, the monomer, styrene, methyl methacrylate, ethylene terephthalate, styrene sulfonate, vinyl acetate, methyl styrene, acrylic acid, butyl methacrylate, ethyl methacrylate, 2-ethylhexyl acrylate, A method for producing fluid particles using tetranomal butyl titanate, characterized in that at least one of N-vinyl caprolactam. The method of claim 1, A surface treatment step of treating the surface of the flowable particles with silane; Method of producing a flowable particles using a tetranomal butyl titanate, characterized in that it further comprises. The method according to claim 1 or 2, In the first mixing step or the second mixing step, pH adjustment step of adjusting the pH of the hydrogen ion index (pH) to 8 to 13 by adding an acid or alkaline solution to the first mixture solution or the second mixture solution; A method for producing fluid particles using tetranomal butyl titanate, further comprising. delete The method according to claim 1 or 2, In the core forming step, the polymerization initiator is 2,2'-azobis (isobutyramidine) hydrochloride (2,2'-azobis (isobutyramidine) hydrochloride) characterized in that the fluidity using tetranomal butyl titanate Method for Producing Particles. The method according to claim 1 or 2, In the core forming step, the dispersion stabilizer is polyvinylpyrrolidone (Poly Vinyl pyrrolidone) characterized in that the manufacturing method of the fluid particles using tetranoyl butyl titanate. The method according to claim 1 or 2, In the core forming step, the solvent comprises water and ethanol, characterized in that the manufacturing method of the fluid particles using tetranomal butyl titanate. 3. The method of claim 2, In the surface treatment step, the silane is tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane or 3,3,3-tree A method for producing fluid particles using tetranomal butyl titanate, characterized in that at least one of fluoropropyltrimethoxysilane (3,3,3-trifluoropropryl methoxysilane) or ethoxytrimethylsilane (ethoxytrimethylsilane). 3. The method of claim 2, In the surface treatment step, the hydrogen ion index (pH) is maintained at 8 to 13, the silane is fluid particles using tetranomal butyl titanate, characterized in that it comprises 5 to 10 parts by weight based on 100 parts by weight of the solvent. Manufacturing method.

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