KR101098538B1 - Fluent particle composition and method of manufacuring fluent particle using teos - Google Patents

Abstract

The present invention relates to a fluid particle composition using TEOS and a method for producing fluid particles using the same, wherein the fluid particle composition using TEOS according to the present invention is based on a solvent and 100 parts by weight of a monomer, 5 to 20 parts by weight, and polymerization. It comprises 0.1 to 3 parts by weight of initiator, 0.5 to 15 parts by weight of dispersion stabilizer, 0.5 to 2 parts by weight of tetranomal butyl titanate, and 0.7 to 5 parts by weight of tetraethyl orthosilicate.

According to the flowable particle composition using TEOS according to the present invention and a method for producing the flowable particles using the same, the reflectivity is significantly improved by using tetranomal butyl titanate, and by using tetraethylorthosilicate, the composition is converted into silica (SiO ₂ ). High conversion, easy formation of particles, use of dispersion stabilizer can improve the dispersion stability of particles, control the generation of aggregation between particles, and due to dispersion polymerization, tetraethylorthosilicate, tetra Adsorption with nomalbutyl titanate is improved, binding particle formation is easy, silane surface treatment can solve the aggregation phenomenon between the charged particles, there is an advantage that can lower the initial drive voltage of the fluid particles.

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

Description

Fluid particle composition using TEOS and manufacturing method of fluid particle using same {FLUENT PARTICLE COMPOSITION AND METHOD OF MANUFACURING FLUENT PARTICLE USING TEOS}

The present invention relates to a flowable particle composition using TEOS and a method for producing a flowable particle using the same, and more particularly, by dispersion polymerization of flowable particles in which tetraethyl orthosilicate and tetranomal butyl titanate are bound to a polymer. The present invention relates to a flowable particle composition using TEOS, which improves reflectance, controls agglomeration between charged particles, provides flowable particles with low initial driving voltage, and excellent durability and fluidity, and a method of manufacturing the flowable particles using the same. will be.

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 an 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, using tetraethyl orthosilicate (tetraethyl orthosilicate) and tetranomal butyl titanate, titanium dioxide (TiO ₂ ) and the monomer by one dispersion polymerization By chemically bonding silica (SiO ₂ ), there is no need for a separate process, so it is economically effective, and unlike the conventional method, it is a chemical bond, and thus, a flowable particle composition using TEOS having excellent bonding durability and excellent fluidity. And it provides a method for producing the flowable particles using the same.

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 fluid particles using TEOS that can control the.

In addition, the dispersion polymerization, compared with the emulsion polymerization, improves the adsorption of tetraethyl orthosilicate and tetranomal butyl titanate, facilitates the formation of binding particles, and can solve the aggregation phenomenon between charged particles due to the silane surface treatment. To provide a method for producing fluid particles using TEOS that can lower the initial driving voltage of the fluid particles.

The flowable particle composition using TEOS of the present invention for achieving the above object is 5 to 20 parts by weight of monomer, 0.1 to 3 parts by weight of polymerization initiator, 0.5 to 15 parts by weight of dispersion stabilizer based on 100 parts by weight of solvent and solvent. , Tetraolemal butyl titanate 0.5 to 2 parts by weight, tetraethyl orthosilicate (Tetraethyl Orthosilicate) is characterized in that it comprises a.

In addition, the dispersion stabilizer is polyvinylpyrrolidone (Poly Vinyl pyrrolidone), characterized in that the monomer is styrene, methyl methacrylate, ethylene terephthalate, styrene sulfonate, vinyl acetate, methyl styrene, acrylic acid, butyl meta It is characterized in that at least one of acrylate, ethyl methacrylate, 2-ethylhexyl acrylate, N-vinyl caprolactam.

In addition, the polymerization initiator is characterized in that the 2,2'-azobis (isobutyramidine) hydrochloride (2,2'-azobis (isobuty ramidine) hydrochloride), the solvent is 20 to 40% by weight of water and It characterized in that it comprises 40 to 80% by weight of ethanol, the flowable particle composition is characterized in that the hydrogen ion index (pH) is 8 to 13.

Method for producing fluid particles using the TEOS of the present invention for achieving the above object, 5 to 20 parts by weight of monomer, 0.1 to 3 parts by weight of polymerization initiator, 0.5 to 15 dispersion stabilizer with respect to 100 parts by weight of solvent and solvent. A core forming step of forming a core by mixing parts by weight; A dissolution step of dissolving tetranomalbutyl titanate in ethanol (EtOH); A first mixing step of preparing a first mixed solution by mixing tetraethyl orthosilicate in the core in an amount of 0.7 to 5 parts by weight based on 100 parts by weight of the solvent; A second mixing step of preparing a second mixed solution by mixing tetraolmalbutyl titanate with 0.5 to 2 parts by weight with respect to 100 parts by weight of the solvent to the first mixed solution; 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 (pH) to 8 to 13 by adding an acid or alkaline solution to the first mixture solution or the second mixture solution; It is characterized in that it further comprises; particle selection step of selecting particles using a sieve made of a hole of 10 to 30㎛.

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 It is characterized in that at least one of the vinyl caprolactam, the polymerization initiator is characterized in that the 2,2'-azobis (isobutyramidine) hydrochloride (2,2'-azobis (isobutyramidine) hydrochloride).

In the core forming step, the dispersion stabilizer is polyvinylpyrrolidone (Poly Vinyl pyrrolidone), characterized in that the solvent comprises 20 to 40% by weight of water and 40 to 80% by weight of ethanol.

In the surface treatment step, the silane is tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane or 3,3,3-tree Fluoropropyltrimethoxysilane (3,3,3-trifluoropropryl methoxy

silane) or ethoxytrimethylsilane, and the hydrogen ion index (pH) is maintained at 8 to 13, and the silane includes 5 to 10 parts by weight based on 100 parts by weight of the solvent. Characterized in that.

According to the flowable particle composition using the TEOS of the present invention, by using tetraethyl orthosilicate and tetraol malbutyl titanate chemically bonds titanium dioxide (TiO ₂ ) and silica (SiO ₂ ) to the monomer, Unlike chemical bonds, the bonds have excellent durability and excellent fluidity.

In addition, by chemically bonding the titanium dioxide (TiO ₂ ) and silica (SiO ₂ ) to the monomer by one dispersion polymerization, there is no need for a separate process has the advantage of excellent economic effect.

In addition, unlike conventional, by using tetraethyl ortho silicate, the conversion to silica (SiO ₂ ) is high, there is an advantage that the formation of particles is easy.

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 of improving the adsorption of tetraethyl orthosilicate and tetranomal butyl titanate, and easy formation of binding particles.

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.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings for a fluid particle composition using TEOS according to the present invention and a method for producing fluid particles using the same. 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 of the composition of the fluid particle composition using the TEOS according to the present invention, and then look at the effect of the present invention through the production method and various examples.

The flowable particle composition using TEOS according to the present invention includes a solvent, a monomer, a polymerization initiator, a dispersion stabilizer, tetranomal butyl titanate (Ti (Obu) ₄ ), and tetraethyl orthosilicate (hereinafter referred to as TEOS). Is done.

The solvent is a mixture of water and ethanol, it is preferable to include 20 to 40% by weight of water, 40 to 80% by weight of ethanol. More preferably, it is most effective to include 28 to 32% by weight of water and 65 to 75% by weight of ethanol. If the content of water and ethanol is out of the range of the above preferred content, the dispersion polymerization is not performed smoothly, therefore, the combination of tetranomal butyl titanate (Ti (Obu) ₄ ) and tetraethylorthosilicate (TEOS) is also normal. There is a problem that is difficult to form.

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 have chargeability. When the monomer is more than 20 parts by weight, silica (SiO ₂ ) and titanium dioxide (TiO ₂ ) as external additives are polymer particles. There is a problem that the durability and fluidity is lowered not enough to surround the surface of the.

As described above, in the present invention, due to the interaction between the polymerization initiator, tetraethylorthosilicate (TEOS) and tetranomalbutylbutyl titanate (Ti (Obu) ₄ ), silica is formed on the surface of the polymer particles produced through the polymerization of the monomer. And titanium dioxide (TiO ₂ ) to form a chemical bond, which is carried out as a mechanism in which the synthetic initiator is a cation, the negative charge of silica and titanium dioxide (TiO ₂ ) is bonded to have a strong ionic bond.

Polymerization 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 charge because the silica particles have a negative charge at a hydrogen ion index (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, it is confirmed that the performance of the best flowable particles 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). Here too, as a result of experiments under the conditions of (a), (b), and (c) of FIG. 3, strong peaks appeared at 1600 to 2000 cm ⁻¹ , and new peaks appeared as Ti-O-Si bonds were formed. Since it is estimated, the case of (b), which also falls within the scope of the present invention, can be seen that the bonding 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 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 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.

Several experiments have shown that the particle size distribution is good and the weight ratio of tetraol-butylbutyl titanate (Ti (Obu) ₄ ) to tetraethyl orthosilicate is preferred for good interaction of silica and titanium dioxide with monomers. Is 1: 1 to 1:10, most preferably 1: 4 to 1: 7. When tetraol-malbutyl titanate (Ti (Obu) ₄ ) is contained in more than the weight ratio, there is a problem in that a reverse reaction occurs and is converted into monomers. As the ethyl orthosilicate content increases, there is a problem that the inside of the fluid particles becomes hollow.

Experimental results on the effect of the content ratio of tetraethylorthosilicate and tetraolmalbutyl titanate on the particles are shown in FIGS. 7 to 11.

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 aggregation phenomenon is the least when maintaining the content ratio of tetraethyl orthosilicate 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.

Tetraolmalbutyl titanate is converted to titanium dioxide (TiO ₂ ), tetraethylorthosilicate (TEOS) to silica (SiO ₂ ) is combined with the monomer, Figure 9 and Table 2 is tetraolmalbutyl titanate and tetra As a result of experiments on the conversion rate according to the content of ethyl orthosilicate (TEOS), it can be seen that the conversion ratio decreases as the content of tetranomal butyl titanate increases. Therefore, it is necessary to maintain the content within the scope of the present invention to properly convert and react, thereby forming a flowable particle combined with a monomer, tetranomal butyl titanate, tetraethyl orthosilicate.

The conversion of tetraolmalbutyl titanate is about 23.5% and the conversion of tetraethylorthosilicate is about 28.9%.

TABLE 2

Ti (Obu) ₄ (g) TEOS (g) TEOS / Ti (Obu) ₄ Volume switched (g) % Of monomer 10g 0 2.5 - 0.72 7.2 0.2 2.3 10 0.71 7.1 0.5 2 4 0.70 7.0 One 1.5 1.5 0.67 6.7 1.67 0.83 0.5 0.63 6.3 2.5 0 - 0.59 5.9

10A is a core particle before tetraethylorthosilicate and tetranomalbutyl titanate are mixed, and FIG. 10B is a case in which the content ratio of TEOS / Ti (Obu) ₄ is 10. FIG. 10C is a diagram of TEOS / Ti (Obu) ₄ . In the case where the content ratio is 4, FIG. 10D is a case where the content ratio of TEOS / Ti (Obu) ₄ is 1.5, and FIG. 10E is a case in which the content ratio of TEOS / Ti (Obu) ₄ is 0.5. As a result of the comparison, in the case of FIGS. 10A and 10B belonging to the TEOS / Ti (Obu) ₄ content range of the present invention, the size of the particles appeared small and evenly, indicating that the particles were well bonded.

11 is a graph measuring the initial driving voltage (v) according to the content ratio of tetraethylorthosilicate and tetranomal butyl titanate, when TEOS / Ti (Obu) ₄ content ratio is 4 (a), TEOS / Ti Comparing (b) in the case of (Obu) ₄ content ratio of 1.5, the initial operating voltage of (a) in the TEOS / Ti (Obu) ₄ content range of the present invention is 120v, which is much lower than 160v of (b). It can be seen that it represents the driving voltage.

Accordingly, the tetraolmalbutyl titanate (Ti (Obu) ₄ ) preferably contains 0.5 to 2 parts by weight based on 100 parts by weight of the solvent, and the tetraethylorthosilicate is 0.7 to 5 parts by weight of 100 parts by weight of the solvent. It is preferred to include parts by weight.

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 using TEOS according to the present invention will be described. The manufacturing method of the fluid particle using TEOS is the same as the description of the fluid particle composition using the TEOS, and will be described below mainly on the characteristics of the manufacturing 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 step ( S50), drying step (S60), surface treatment step (S70), pH adjustment step (S31, S41) is made to include.

Core forming step (S10) is a step of forming a core by mixing 5 to 20 parts by weight of monomer, 0.1 to 3 parts by weight of polymerization initiator, 0.5 to 15 parts by weight of dispersion stabilizer based on 100 parts by weight of the solvent and the 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 tetraethyl orthosilicate, and proceeds with the following mixing process after dissolving tetranomal butyl titanate in ethanol.

The first mixing step (S30) is a step of preparing a first mixed solution by mixing tetraethyl orthosilicate (0.7 to 5 parts by weight) with respect to 100 parts by weight of the solvent in the core.

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 tetranomal butyl titanate to 100 parts by weight of the solvent in the first mixture solution. 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 tetraethyl orthosilicate (a), when tetraethyl orthosilicate is mixed first and then tetranomal butyl titanate is mixed (b), Comparing the case of first mixing tetranomal butyl titanate and then mixing tetraethyl orthosilicate (c) in the SEM picture, in the case of (a) in the case of the reverse reaction is converted into monomers, no particles are formed, In the case of (c), particles cannot be formed because separation is impossible, and thus, fluid particles are normally formed only when tetraethylorthosilicate 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 15 to 24 hours to prepare fluid 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. .

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 reaction 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>

FIG. 16 and Table 3 show the results of Experiment 1, FIG. 17 and Table 4 show the results of Experiment 2, except that only the weight ratio of tetraethylorthosilicate and tetranomal butyl titanate was varied, and the results of the silane treatment were performed. FIG. 16 and FIG. As shown in 17, Table 3, and Table 4, the silane-treated particles were noticeably lower than the silane-treated particles, among which CF ₃ -TES and CF ₃ -TMS treatments were more effective than ETMS. It was found that the initial driving voltage can be lowered.

TABLE 3

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

TABLE 4

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 5 are the experimental results of measuring the change in the initial drive voltage according to the content of the silane, as shown in Figure 18 and Table 5, when the silane is included in 100 parts by weight of solvent, 3 parts by weight 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 5

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 6 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 6

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

In addition, the particle selection step (S80) is a step of selecting only particles of an appropriate size by passing the manufactured fluid particles through a sieve in which a plurality of holes exist. It is preferable that the hole size of the sieve in the particle selection step (S80) is 10 to 30㎛, most preferably 15 to 25㎛. If the size of the hole is less than 10㎛, there is a problem that most of the particles are filtered smaller than the size of the particles, if the size exceeds 30㎛ most of the particles are not filtered, there is a problem that the effect of particle selection.

As shown in FIG. 20 and Table 7, the initial driving voltage (v) was compared when the sieve was not sifted, when the sieve was hit with a 25 μm sieve, and when the sieve was hit with a 15 μm sieve. When the sieve was high, the initial driving voltage was measured to be low, and the sieve stage showed excellent flowable particle performance.

<Table 7>

Initial drive voltage (v) If not hit 130 When hit with 25㎛ sieve 80 When hit with a 15㎛ sieve 80

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 of the particles according to the content ratio of tetranomal butyl titanate and tetraethyl orthosilicate

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

FIG. 9 is a graph showing the conversion rate of tetraolmalbutyl titanate according to the content ratio of tetraethylorthosilicate and tetraolmalbutyl titanate

10 is a graph showing the size distribution of particles according to the content ratio of tetraethylorthosilicate and tetraolmalbutyl titanate

11 is a graph showing the driving voltage (V) according to the content ratio of tetraethylorthosilicate and tetraolmalbutyl titanate

12 is a flow chart sequentially showing a method for producing flowable particles using TEOS 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 tetraethylorthosilicate and tetraolmalbutyl 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

20 is a graph showing the driving voltage (V) when sifting fluid particles

<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 (16)

5 to 20 parts by weight of monomer, 0.1 to 3 parts by weight of polymerization initiator, 0.5 to 15 parts by weight of dispersion stabilizer, 0.5 to 2 parts by weight of tetranomal butyl titanate, tetraethyl orthosilicate (Tetraethyl Orthosilicate) ) 0.7 to 5 parts by weight, including The monomer is at least one of styrene, methyl methacrylate, ethylene terephthalate, styrene sulfonate, vinyl acetate, methyl styrene, acrylic acid, butyl methacrylate, ethyl methacrylate, 2-ethylhexyl acrylate, and N-vinyl caprolactam Flowable particle composition using TEOS, characterized in that one. The method of claim 1, The dispersion stabilizer is a fluid particle composition using TEOS, characterized in that the poly vinyl pyrrolidone (Poly Vinyl pyrrolidone). delete The method according to claim 1 or 2, The polymerization initiator is 2,2'- azobis (isobutyramidine) hydrochloride (2,2'-azobis (isobuty ramidine) hydrochloride) characterized in that the fluid particle composition using TEOS. The method according to claim 1 or 2, The solvent is a flowable particle composition using TEOS, characterized in that 20 to 40% by weight of water and 40 to 80% by weight of ethanol. The method according to claim 1 or 2, The flowable particle composition is a flowable particle composition using TEOS, characterized in that the hydrogen ion index (pH) is 8 to 13. 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 tetraethyl orthosilicate in the core in an amount of 0.7 to 5 parts by weight based on 100 parts by weight of the solvent; A second mixing step of preparing a second mixed solution by mixing 0.5 to 2 parts by weight of the tetranomal butyl titanate with respect to 100 parts by weight of the solvent in the first mixed solution; A polymerization step of polymerizing the second mixed solution at a temperature of 40 to 90 ° C. for 15 to 24 hours to produce fluid particles; And It includes; drying step of drying the flowable particles, 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 Method for producing fluid particles using TEOS, characterized in that at least one of-vinyl caprolactam. The method of claim 7, wherein The surface treatment step of treating the surface of the flowable particles with silane; Method of producing a flowable particles using TEOS, characterized in that it further comprises. The method according to claim 7 or 8, 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; Method for producing flowable particles using TEOS, characterized in that it further comprises. The method according to claim 7 or 8, Selecting the particles to select the particles using a sieve made of a hole of 10 to 30㎛; Method for producing flowable particles using TEOS, characterized in that it further comprises. delete The method according to claim 7 or 8, In the core forming step, the polymerization initiator is 2,2'-azobis (isobutyramidine) hydrochloride (2,2'-azobis (isobutyramidine) hydrochloride) characterized in that the manufacturing method of the fluid particles using TEOS . The method according to claim 7 or 8, In the core forming step, the dispersion stabilizer is polyvinyl pyrrolidone (Poly Vinyl pyrrolidone) characterized in that the manufacturing method of the fluid particles using TEOS. The method according to claim 7 or 8, In the core forming step, the solvent is 20 to 40% by weight of water and 40 to 80% by weight of ethanol, characterized in that the manufacturing method of the fluid particles using TEOS. The method of claim 8, In the surface treatment step, the silane is tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane or 3,3,3-tree A fluoropropyl trimethoxysilane (3,3,3-trifluoropropryl methoxysilane) or ethoxytrimethylsilane (ethoxytrimethylsilane), characterized in that at least one of the manufacturing method of the fluid particles using TEOS. The method of claim 8, In the surface treatment step, the hydrogen ion index (pH) is maintained at 8 to 13, wherein the silane comprises 5 to 10 parts by weight based on 100 parts by weight of the solvent, characterized in that the manufacturing method of the fluid particles using TEOS.

Images