WO2012141530A2

WO2012141530A2 - Method for manufacturing external additive for electronic paper particle using titanium dioxide and external additive for electronic paper particle using titanium dioxide manufactured thereby

Info

Publication number: WO2012141530A2
Application number: PCT/KR2012/002823
Authority: WO
Inventors: 이상국; 최경호; 신교직; 김은경; 정승용
Original assignee: 한국생산기술연구원
Priority date: 2011-04-14
Filing date: 2012-04-13
Publication date: 2012-10-18
Also published as: WO2012141530A3; KR20120117247A; KR101215895B1

Abstract

The present invention relates to a method for manufacturing an external additive for an electronic paper particle using titanium dioxide, and to the external additive for the electronic particle using the titanium dioxide manufactured thereby, and comprises: an amino group provision step of adding hydrochloric acid to a first solvent, to which the titanium dioxide is added, reacting same, and manufacturing the titanium dioxide having the amino group; and a charge provision step of adding ammonia water to a second solvent, to which the titanium dioxide having the amino group is added, and reacting same. According to the present invention, the external additive can be more quantitatively and uniformly adsorbed to the particle by using a solution adsorption method, and a chemical combination can significantly enhance durability. Furthermore, by synthesizing the amino group to the titanium dioxide, clumping between the particles can be prevented and advantageously and significantly increases particle mobility.

Description

Method for preparing electronic particle external additive using titanium dioxide and particle external additive for electronic paper using titanium dioxide prepared using the same

The present invention relates to a method for preparing an electronic paper particle additive using titanium dioxide and an electronic paper particle additive using titanium dioxide prepared using the same. More specifically, unlike the conventional method, a solution adsorption method is used. And chemically adsorbing functional groups on the external additives to impart a strong charge to the particles, prevent the aggregation of particles, and significantly improve the durability and fluidity. It relates to a particle external additive for electronic paper using titanium dioxide prepared using the same.

BACKGROUND ART Conventionally, as an image display device replacing a liquid crystal display device (LCD), electronic paper using techniques such as an electrophoretic 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. , Electronic paper and the like are expected.

The dual electronic paper technology uses the rapid movement of microparticles by an electric field to electrostatically move charged particles floating in a certain space to display colors. Therefore, 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 as if printed on paper is printed. 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, low prices due to simple processes and low cost materials are expected to contribute to the popularization of electronic paper.

Electronic paper techniques generally used include electrophoretic methods for microencapsulating a dispersion consisting of dispersed particles and a colored solution, and disposing the dispersion liquid 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.

Regardless of which type of electrophoresis method or collision charging method is used, a technique for forming a charged particle having a fluidity (hereinafter referred to as a 'fluid particle') should be accompanied, and the fluid particle may have a coupling agent or the like on the surface of the particle. The structure which gives fluidity | liquidity is shown by coating the same external additive.

The flowable particles include an external blending method using a mixer by adding an external additive to a dispersion solvent containing the particles. The flowable particles in this manner, the particles and the external additives are physically bonded, due to the limitation of the durability of the physical bonds, there is a problem that the external components easily fall off.

When the external additives fall easily in this way, the charged particles cannot sufficiently respond to the same applied voltage, and the charge characteristics also change easily, resulting in 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.

In addition, since the physical bonding, due to the electrostatic attraction between the particles and the external additive, there is a problem that the binding between the particles and the external additive is not quantitatively and uniformly.

In addition, in the case of the polymer particles used in the flowable particles, a polymerization method according to emulsion polymerization, dispersion polymerization or suspension polymerization is used. Since the polymer particles thus prepared mostly exhibit lipophilic surface properties, hydrophilic functional groups are formed on the surface. It is difficult to apply a new polymerization method for the introduction of the hydrophilic functional group in order to obtain the polymer particles bound, and unlike most commercial lipophilic polymer particles, very high in order to obtain the polymer particles into which the hydrophilic functional groups are introduced. In addition to the cost, there is a problem in that a cumbersome and inexpensive manufacturing method such as using a surfactant is used.

In addition, the binding problem between the particles and the external additives causes the same problems as described above in the binding of the external additives and the substances added to the external additives.

Therefore, in order to solve various problems such as fluidity, durability, and prevention of particle aggregation of the fluid particles, the development of a method for solving such problems by modifying the external additive itself is required, and effectively There is a need for development of a process for bonding, and a process for chemically and uniformly bonding external additives to flowable particles, rather than physically, and simply implementing such bonding.

The present invention is to solve the above problems, unlike the prior art, by using a solution adsorption method, not only can adsorb functional groups to the external additive more quantitatively and uniformly, but also due to chemical bonding, significantly improve the durability It is an object of the present invention to provide a method for producing an electronic paper particle additive using titanium dioxide and an electronic paper particle additive using titanium dioxide prepared using the same.

In addition, by synthesizing an amino group to titanium dioxide, a method of preparing an external particle additive for electronic paper using titanium dioxide that can suppress particle aggregation and significantly improve fluidity, and electronic paper using titanium dioxide prepared using the same It is an object to provide a particle external additive.

In addition, by reacting titanium dioxide with an amino group with ammonia water and giving sufficient charge to the external additive, a strong charge is formed throughout the particles, thereby increasing the fluidity of the particles and significantly reducing the interference between particles. It is an object of the present invention to provide a method for producing an electronic paper particle additive using titanium dioxide and an electronic paper particle additive using titanium dioxide prepared using the same.

In addition, by effectively preparing the external additive through the optimal material and its content, it is possible to form chemical bonds simply and economically, and in particular, by increasing the color of the white particles, the external additive improves the contrast ratio in the electronic paper apparatus. An object of the present invention is to provide an electronic paper particle additive for electronic paper using titanium dioxide and an electronic paper particle additive for titanium paper prepared using the same.

Method for producing an electronic paper particle additive using titanium dioxide according to the present invention for achieving the above object, the purification step of purifying titanium dioxide by heat treatment at 300 to 500 ℃ for 15 to 30 hours; And an amino group substitution step of adding titanium dioxide to a solvent and reacting to produce titanium dioxide having an amino group.

In the amino-substituted step, the solvent is characterized in that toluene, the amino-substituted step, after the addition of the titanium dioxide to the solvent, dispersing to prepare a reaction solution to prepare a reaction solution; A heating step of heating the reaction solution under a nitrogen atmosphere; An ethoxysilane addition step of adding (3-aminopropyl) triethoxysilane to the reaction solution; And a stirring step of stirring the reaction solution.

In addition, in the reaction solution preparation step, the titanium dioxide is characterized in that 20 to 50 parts by weight with respect to 100 parts by weight of the solvent, the heating step, the temperature of the reaction solution to a temperature of 60 ℃ to 90 ℃ It is characterized by maintaining.

In the ethoxysilane addition step, based on 100 parts by weight of the solvent, the (3-aminepropyl) triethoxysilane is characterized in that 20 to 50 parts by weight, the stirring step, the reaction solution to 60 ℃ It is characterized by stirring for 15 to 30 hours at a temperature of 90 ℃.

According to the present invention, a method for producing an electronic paper particle additive using titanium dioxide and an electronic paper particle additive using titanium dioxide prepared by using the same, unlike the conventional method, is more quantitative and uniform by using a solution adsorption method. Not only can the functional group be adsorbed to the external additive, but also due to the chemical bonding, there is an advantage that can significantly improve the durability.

In addition, by effectively synthesizing the amino group in titanium dioxide, there is an advantage that can suppress the aggregation between particles and significantly improve the fluidity.

In addition, by reacting titanium dioxide with an amino group with ammonia water and giving sufficient charge to the external additive, a strong charge is formed throughout the particles, thereby increasing the fluidity of the particles and significantly reducing the interference between particles. There is an advantage.

In addition, by effectively preparing the external additive through the optimal material and its content, it is possible to form chemical bonds simply and economically, and in particular, by increasing the color of the white particles, the external additive improves the contrast ratio in the electronic paper apparatus. There is an advantage to this.

1 is a flow chart sequentially showing a manufacturing method of the particle external additive for electronic paper using titanium dioxide according to the present invention.

Figure 2 is a cross-sectional view showing that the electronic particle external additive for electronic paper using titanium dioxide prepared by using the method for producing an electronic paper particle external additive using titanium dioxide according to the present invention attached to the electronic paper particles

Hereinafter, a method for producing an electronic paper particle additive using titanium dioxide according to the present invention and an electronic paper particle additive using titanium dioxide prepared by using the same according to an embodiment of the present invention. It demonstrates in detail with reference. 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.

As shown in FIG. 1, the method for preparing an external particle for electronic paper using titanium dioxide according to the present invention is characterized in that it comprises a purification step (S10) and an amino group substitution step (S20).

The purification step (S10) is a step of purifying titanium dioxide by heat treatment at 300 to 500 ℃ for 15 to 30 hours. This is a heat treatment process that effectively removes and purifies moisture and impurities in titanium dioxide without damaging titanium dioxide.

In addition, the heat treatment temperature is preferably 300 to 500 ° C, more preferably 350 to 450 ° C. If the temperature is less than 300 ° C., there is a problem in that the moisture and impurities are not sufficiently purified, and if the temperature exceeds 500 ° C., there is a problem that damage may occur to the titanium dioxide itself.

The heat treatment time is preferably 15 to 30 hours, more preferably 20 to 25 hours. If less than 15 hours, there is a problem that can not be sufficiently refined, if more than 30 hours there is a problem that not only economic efficiency, but also damage to titanium dioxide.

Here, since titanium dioxide is used as the external additive of the particles for electronic paper, since it is white, there is an advantage that the contrast ratio with respect to the white particles can be increased, and it is easy to combine with the electronic paper particles, and the durability is effective as an external additive. to be.

Next, the amino group substitution step (S20) is a step of preparing titanium dioxide having an amino group by adding the titanium dioxide to the solvent and reacting. This is a process for remarkably improving the fluidity of particles and preventing agglomeration by providing amino groups to titanium dioxide.

In the amino group substitution step (S20), the solvent does not interfere with the amino group substitution reaction, any solvent may be any help, in the present invention, several times the experiment results, it is most preferable to use toluene.

In addition, the amino group substitution step (S20), preferably comprises a reaction solution preparation step (S21), heating step (S22), ethoxysilane addition step (S23) and stirring step (S24).

First, the reaction solution preparation step (S21) is a step of preparing the reaction solution by adding the titanium dioxide to the solvent, and then dispersed. This is a reaction preparation process in which titanium dioxide is mixed in an optimum amount in a solvent and then dispersed to facilitate the reaction.

In the reaction solution preparation step (S21), the titanium dioxide is preferably added to 20 to 50 parts by weight, more preferably 30 to 40 parts by weight based on 100 parts by weight of the solvent. If the amount of titanium dioxide is less than 20 parts by weight, the amount contained in the solvent is too small, there is a problem that the substitution reactivity of the amino group is inferior, if more than 50 parts by weight of titanium dioxide is not sufficiently dispersed in the solvent it is difficult to effectively react However, there is a problem that a sufficient amino group is hardly given to titanium dioxide.

Next, the heating step (S22) is a step of heating the reaction solution under a nitrogen atmosphere. This is a process for creating an effective reaction environment for amino group substitution by maintaining a constant high temperature under a nitrogen atmosphere.

In the heating step (S22), it is preferable to maintain the temperature of the reaction solution at a temperature of 60 ℃ to 90 ℃, more preferably it is effective to maintain a temperature of 70 ℃ to 80 ℃. If it is less than 60 ℃ there is a problem that the reaction between the nitrogen and the reaction solution is difficult to occur, and if it exceeds 90 ℃ there is a problem that the reaction solution is difficult to maintain the optimum content ratio due to the high temperature.

In addition, the ethoxysilane addition step (S23) is a step of adding (3-aminopropyl) triethoxysilane ((3-aminopropyl) triethoxysilane) to the reaction solution. This is a step of adding a reactant of a substitution reaction to give an amino group to titanium dioxide particles.

In the ethoxysilane addition step (S23), the (3-aminepropyl) triethoxysilane is preferably 20 to 50 parts by weight, and more preferably 30 to 40 parts by weight based on 100 parts by weight of the solvent. effective. If it is less than 20 parts by weight, a sufficient amino group is difficult to be imparted to the titanium dioxide phase, and if it exceeds 50 parts by weight, it is difficult to uniformly distribute an appropriate amount of the amino groups imparted onto the titanium dioxide, rather the fluidity of the particles is lowered. There is a problem.

Finally, the stirring step (S24) is a step of stirring the reaction solution. This is a process of reacting (3-aminepropyl) triethoxysilane with titanium dioxide under a nitrogen atmosphere.

In the stirring step (S24), the reaction solution is preferably stirred for 15 to 30 hours at a temperature of 60 ℃ to 90 ℃, more preferably for 20 to 25 hours at a temperature of 70 ℃ to 80 ℃ Is effective. If the temperature is lower than 70 ° C., the temperature is low, and the reactivity decreases, thereby making it difficult to sufficiently bond the amino group to titanium dioxide. If the temperature exceeds 90 ° C., the reaction rate is increased, but the amino group is uniformly bound to the titanium dioxide. It is difficult to achieve, and there is a problem that the reactants are damaged.

In addition, after the stirring step (S24) is not an essential step, it is preferable to add a drying step (S25).

Drying step (S25) is divided into a step of washing the titanium dioxide having the reaction- terminated amino group with toluene and after washing, the step of sufficiently drying at 15 to 30 ℃ for 24 to 48 hours. First, by washing, by removing the unreacted material, thereby improving the external reactivity to the particles, and serves to facilitate the subsequent particle surface treatment process through the drying process.

Next, the particle external additive for electronic paper using titanium dioxide prepared according to the present invention, as shown in Fig. 2, bare particles (10), and the external additive particles attached to the bare particles (10) (20), and the chemical bond 30 between the external additive particles 20 and the amino group 40 attached to the external additive particles 20.

Here, the bare particles 10 are preferably white particles in accordance with the color of the particle external additive for electronic paper using titanium dioxide of the present invention.

In addition, the charge of the external additive particle 20 is negative (-), and by externally externalizing the external additive particle 20 of the present invention, which bears (-) charge to both the (+) and (-) bare particles 10, Aggregation between particles can be completely prevented.

In addition, through the combination of the external additive particles 20 and the bare particles 10 produced by the present invention, it prevents the aggregation phenomenon as the particles for the electronic paper, excellent driveability and color implementability, the optimum charge There is an outstanding advantage.

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.

Claims

A purification step of purifying titanium dioxide by heat treatment at 300 to 500 ° C. for 15 to 30 hours; And

Amino-substituted step of preparing the titanium dioxide having an amino group by the reaction by adding the titanium dioxide to the solvent; Method of producing a particle external additive for electronic paper using titanium dioxide, characterized in that it comprises a
The method of claim 1,

In the amino group substitution step, the solvent is a method for producing an electronic paper particle additive using titanium dioxide, characterized in that toluene.
The method according to claim 1 or 2,

The amino group substitution step, after the addition of the titanium dioxide to the solvent, to prepare a reaction solution by dispersing the reaction solution;

A heating step of heating the reaction solution under a nitrogen atmosphere;

An ethoxysilane addition step of adding (3-aminopropyl) triethoxysilane to the reaction solution; And

Method for producing a particle external additive for electronic paper using titanium dioxide, characterized in that it comprises a; stirring step of stirring the reaction solution;
The method of claim 3, wherein

In the reaction solution preparation step, the titanium dioxide is a manufacturing method of the particle external additive for electronic paper using titanium dioxide, characterized in that 20 to 50 parts by weight based on 100 parts by weight of the solvent.
The method of claim 3, wherein

The heating step, the production method of the particle external additive for electronic paper using titanium dioxide, characterized in that to maintain the temperature of the reaction solution at a temperature of 60 ℃ to 90 ℃.
The method of claim 3, wherein

In the ethoxysilane addition step, with respect to 100 parts by weight of the solvent, the (3-aminepropyl) triethoxysilane is 20 to 50 parts by weight, characterized in that the manufacturing method of the particle external additive for electronic paper using titanium dioxide.
The method of claim 3, wherein

In the stirring step, the reaction solution is prepared for a particle external additive for electronic paper using titanium dioxide, characterized in that for 15 to 30 hours under a temperature of 60 ℃ to 90 ℃.
Particle additive for electronic paper using titanium dioxide, characterized in that prepared by any one of claims 1 to 7.