KR101369952B1 - Method for manufacturing toner by shirasu-porous-glass membrane reactor - Google Patents

Abstract

The present invention relates to a method for producing toner particles. More specifically, in the method for producing toner particles by polymerizing monomer solution, the monomer solution to be polymerized is dispersed in a solvent by a membrane reactor, and the membrane reactor is a monomer solution stream, a solvent stream, and both streams. It relates to a method for producing toner particles, characterized by having an SPG film therebetween. According to the present invention, it is possible to easily produce toner particles having a uniform particle size in a monodisperse manner, and to effect emulsion polymerization of the toner particles continuously.

SPG, membrane reactor, continuous, toner, monomer solution, solvent, stream

Description

METHODS FOR MANUFACTURING TONER BY SHIRASU-POROUS-GLASS MEMBRANE REACTOR}

The present invention relates to a method for producing toner particles, and more particularly, to a method for producing toner particles using an SPG membrane reactor.

The method of preparing O / W and W / O emulsions using the physicochemical properties of emulsifiers (e.g. PIT method, D-phase method) has been studied a lot, such as colloid mill, homogenizer, ultrasonic emulsifier Emulsifiers are also being developed.

However, these methods have difficulty in precisely controlling the process and have a disadvantage in that the particle size distribution of the prepared emulsion is polydispersed. To overcome this problem, the film emulsification method developed in Japan in 1980 is an example. This technique is to prepare an emulsion with uniform particle distribution by using a SPG (Shirasu Porous Glass) membrane with a uniform pore size among porous glass membranes.

The conditions to be used for such a film emulsification is as follows.

① The pore size of membrane should be uniform.

② The pore size of the membrane should be possible to manufacture the desired size according to the manufacturing conditions.

③ The membrane should not be deformed or broken by the pressure provided during the reaction.

④ In the case of O / W emulsions, the membrane surface should not be wetted by oil phase or polymer solution.

(5) The membrane should contact the continuous phase preferentially rather than the dispersion phase.

⑥ The pores should be cylindrical (cylindrical) without any constriction.

Among the organic or inorganic porous membranes currently produced, only SPG satisfies all of the above conditions. For example, problems of ①, ③, and other inorganic films such as alumina have been found to be ①, ⑤, and ⑥.

The Shirasu Porous Glass (SPG) membrane, first published by Nakashima and Shimizu in Japan, is a porous glass membrane made from volcanic ash widely distributed in Miyazaki Prefecture, Kyushu, Japan. Superior to the like中島Japanese late 1970s, Vycor-type, and made to have a relatively large pore size range in 4㎚ ~ 20 ㎛, then the Japanese technology resulting new _{CaO-Al 2 O 3 -B 2} O 3 - SiO ₂ porous glass membrane was made, which is called SPG (Shirasu Porous Glass). It has numerous pores of constant size and is a porous glass membrane of various sizes, from nanometer to micrometer in size. Currently, it is applied to separation functions, absorbents, or drug carriers in various industries such as medicine, food, and cosmetics.

The emulsification method by SPG (Shirasu Porous Glass) has been studied because of the advantage that it can be effectively controlled to have a narrow droplet distribution while using less energy.

 On the other hand, there are the following characteristics of the film emulsification method.

① By using membrane with different pore size, emulsion particle size can be freely adjusted in the range of 0.1 ~ 10 ㎛.

The particle distribution of the emulsion is very monodispersed compared to the conventional method.

③ Emulsion stability can be obtained even with a small amount of emulsifier.

④ Double emulsions of O / W / O and W / O / W can be prepared relatively easily by using two kinds of porous glass membranes.

⑤ It does not need strong stirring, so there is an advantage of reducing the operating cost.

⑥ Combination of membrane emulsification and suspension polymerization produces polymer microspheres with uniform particles.

⑦ A homogeneous silica microsphere is produced by the combination of membrane emulsification and interfacial reaction.

⑧ It is easy to scale up because of simple process and is suitable for mass production.

⑨ It is very suitable for high value added and differentiated product development.

Among these various features, ① ~ ③ are important features not seen in the conventional emulsification method.

The emulsion droplets produced using the membranes then have various types of particle structures by successive reactions or processes such as polymerization, gelation, volatilization, freeze drying, solidification, crystallization, and swelling. O / W, W / O or M / W emulsion droplets are formed by the hydrophilic or hydrophobic nature of the membrane and the two liquid phase components. A single emulsion is transformed from a plurality of emulsions or droplets to a solid or from a continuous phase to a solid phase through a secondary emulsification method.

The development of emulsification methods is rooted in two possible manufacturing approaches. One is to reduce the perturbation by increasing the uniformity of the mixing process that destroys the droplet, or the second is to prepare droplets one by one using a micro-engineering structure system. Membrane and microchannel emulsification forms emulsified droplets by droplets pushed out of numerous pores or outlets of microchannels, an example of a second approach.

Generally, emulsion polymerization, suspension polymerization, bulk polymerization, and the like are used as polymerization methods of toner resins.

Among these, the resin for toner prepared by emulsion polymerization is made into a powder form because the particle size is small to prepare the toner, and the carbon black and the charge control agent are mixed and dispersed, and the powder mixture is extruded and cooled in an extruder, followed by jet mill ( It is troublesome to prepare a toner having a desired particle size by grinding with a jet mill.

In addition, the resin for toner produced by the suspension polymerization method has a disadvantage in that the particle size is suitable for manufacturing the toner, but the particle size distribution is polydisperse, so that the particle size distribution must be made monodisperse through a sifting process. There is a problem.

Carbon black is mainly used as a colorant for the toner resin, and the structure of the carbon black crystal is a planar layer of a layer in which about 90 carbon atoms are arranged in a hexagonal network of about 90 carbon atoms, which are seen as a polycyclic compound, such as a graphite crystal structure. It is a structure overlapping at intervals of about 5 to 5 layers, the initial particles are aggregated to exist as aggregates under the influence of the surface energy. In addition, since the surface area is larger than other additives, the cohesive force between the aggregates is strong, making it difficult to disperse among various pigments and additives.

Therefore, the dispersion of carbon black in the resin is an important factor in determining the value of the product because it affects the blackness, surface properties, conductivity and mechanical properties of the final product.

In the present invention, the hassle of the process by the conventional emulsion polymerization or suspension polymerization, and the carbon black to improve the dispersibility, the particle size is monodisperse by dispersing the carbon black in the monomer and then polymerizing by applying the film emulsion method It is an object of the present invention to provide a method for easily manufacturing uniform toner particles. In particular, as a membrane reactor having a SPG film having a uniform particle size is used, it is possible to continuously produce monodisperse droplets, unlike a method of preparing droplets in a conventional batch form. To provide.

According to the present invention,

A method of polymerizing a monomer solution to produce toner particles, wherein the monomer solution to be polymerized is dispersed in a solvent by a membrane reactor, and the membrane reactor includes an SPG film between the monomer solution stream, the solvent stream, and both streams. It provides a method for producing toner particles, characterized in that one.

In the present invention, the SPG membrane pore size provides a method for producing toner particles, characterized in that within the range of 2 ~ 10 ㎛.

In addition, in the present invention, the pressure difference between the SPG film provides a toner particle manufacturing method, characterized in that within the range of 0.1 ~ 20 Kgf / ㎠.

In addition, in the present invention, the monomer solution stream provides a method for producing toner particles, characterized in that within the range of 40 ~ 60 ℃.

In another aspect, the present invention provides a method for producing toner particles, characterized in that the flow rate of the monomer solution stream is within the range of 0.1 ~ 10ml / min.

In another aspect, the present invention provides a method for producing toner particles, characterized in that the flow rate of the solvent stream is within the range of 30 ~ 100ml / min.

In addition, in the present invention, the monomer solution provides a method for producing toner particles, characterized in that it comprises carbon black, wax, monomer, charge control agent, dispersant and initiator.

In addition, in the present invention, the monomer solution includes carbon black 2-8 wt%, wax, 50-70 wt% monomer, 0.3-3 wt% charge control agent, 0.5-5 wt% dispersant and 4-7 wt% initiator. It provides a method for producing toner particles, characterized in that.

In the present invention, the solvent provides a method for producing toner particles, characterized in that the water.

Also provided is a toner particle, which is prepared by the method of the present invention.

Also provided by the method of the present invention is toner particles characterized in that the dispersion degree is 1.0 or less.

According to the present invention, it is possible to easily produce toner particles having a uniform particle size in a monodisperse manner, and to effect emulsion polymerization of the toner particles continuously.

Hereinafter, the present invention will be described in detail.

The present invention provides a method of polymerizing a monomer solution to produce toner particles, wherein the monomer solution to be polymerized is dispersed in a solvent by a membrane reactor, and the membrane reactor is disposed between the monomer solution stream, the solvent stream, and the both streams. It is characterized by including the SPG film.

In order to obtain toner particles having a uniform particle distribution, the particle size distribution of the toner particles is dispersed through a process in which a monomer solution including carbon black, wax, and charge control agent is passed through an SPG membrane into a solvent containing a dispersant. To be good.

Figure 1 shows one embodiment of the production method of the present invention and one embodiment of the membrane reactor of the present invention.

In the present invention, the SPG membrane pore size is preferably within the range of 2 ~ 10 ㎛. The size of the particles can be adjusted according to the pores, but in order to be used as toner particles, the particle size is appropriately about 6 to 15 μm, and in order to prepare the particles, the size of the SPG membrane pores is appropriately 2 to 10 μm. .

In the present invention, the pressure difference between the SPG membrane is preferably within the range of 0.1 ~ 20 Kgf / ㎠ (the pressure difference is a monomer because the pressure of the monomer solution stream must be greater than that of the solvent stream will be smoothly dispersed into the solvent Solution should rise in a larger direction). Below 0.1 Kgf / cm 2, low pressure differentials are undesirable in terms of productivity as the number of monomer droplets passing through the SPG membrane per unit time decreases. Above 20 Kgf / cm 2, there is a fear that the SPG membrane is broken due to the high pressure difference. SPG membrane is a porous inorganic material, so it has a cracking nature, it should be noted. However, when the inventors of the present invention consider the results of the experiments leading to the invention, it is considered that the pressure difference is not a factor influencing the generated toner particle size.

In the present invention, the temperature of the monomer solution stream is preferably within the range of 40 to 60 ℃. If it is less than 40 ℃, the fluidity of the wax (wax) can be reduced to prevent the pores of the SPG membrane, if it is above 60 ℃, the polymerization reaction rate is increased rapidly by the initiator contained in the monomer solution, polymerization before even passing through the SPG membrane It is undesirable because a reaction can occur.

In the present invention, the flow rate of the monomer solution stream is preferably in the range of 0.1 to 10 ml / min. At less than 0.1 ml / min, the amount of toner particles produced per unit time is not preferable, and at more than 10 ml / min, the size of the monomer droplets may become irregular, in particular, the monomers dispersed before the stabilized monomer droplets first stabilize. It is more likely to merge with the droplets.

In the present invention, the flow rate of the solvent stream is preferably in the range of 30 to 100 ml / min. At less than 30 ml / min, the monomer solution may not be stabilized quickly when it is dispersed, which is undesirable. At more than 100 ml / min, monomer droplets may not be formed properly due to the rapid flow of the solvent when the monomer solution is dispersed and dispersed. It is not desirable.

In the present invention, the monomer solution includes carbon black, wax, monomer, charge control agent, dispersant and initiator.

In the present invention, the monomer solution includes carbon black 2-8 wt%, wax, 50-70 wt% monomer, 0.3-3 wt% charge control agent, 0.5-5 wt% dispersant and 4-7 wt% initiator. will be.

In the present invention, the solvent is preferably water. It is more preferable that 1 to 20 wt% of the dispersant is included here. Too little dispersant or less solvent relative to the monomer solution results in a lower dispersion stability of the monomer solution, which can cause unwanted droplets to interact with the monomer particles across the membrane. On the contrary, too much dispersant or too much solvent in comparison with the monomer solution will result in poor fluidity of the solvent solution and poor toner particle productivity.

Hereinafter, the present invention will be described in more detail with reference to Examples. Embodiment of the present invention is for the detailed description of the invention, not intended to limit the scope of the right.

Example 1

The inside of the membrane reactor is filled with distilled water, the outside of the reactor with styrene (styrene) and put in a 60 ℃ thermostat and the temperature is raised in advance. Start the experiment with the raw material solution warmed to 55 ° C.

A monomer solution stream containing 4.9 wt% of carbon black was introduced at the outside of the membrane at 0.2 mL / min and a solvent stream containing 2.5% of the dispersant was flowed at the inside of the membrane at 30 mL / min.

2 shows an electron micrograph of the toner particles of Example 1. FIG.

Example 2

The same method as in Example 1 was used. However, the monomer solution stream was charged at 0.33 mL / min and the solvent stream at 50 mL / min.

3 shows an electron micrograph of the toner particles of Example 2. FIG.

[Particle Size Distribution of Toner Particles]

The particle size distribution of the toner particles was measured, and the results are shown in Table 1 below.

Dispersion degree D _10% D _50% D _90% Example 1 0.37 10.23 11.90 14.65 Example 2 1.00 0.90 1.62 2.51

The dispersion degree α value of the toner particles is defined as in Equation 1 below.

As shown in Table 1, it can be seen that the dispersion of the toner particles can be very low by polymerizing the dispersed monomer solution using the SPG membrane reactor. The low degree of dispersion means that the particles are even and uniform, indicating that the toner is of good quality, and thus the toner produced by the method of the present invention may be evaluated to be excellent in quality.

1 is one embodiment showing the membrane reactor of the present invention.

2 is an electron micrograph of the toner particles of Example 1. FIG.

3 is an electron micrograph of the toner particles of Example 2. FIG.

Claims (11)

In the method for producing toner particles by polymerizing a monomer solution, The monomer solution to be polymerized is dispersed in a solvent by a membrane reactor, The membrane reactor has an SPG membrane between the monomer solution stream, the solvent stream, and both streams, Toner particles production method characterized in that the pressure difference between the SPG film is within the range of 0.1 ~ 20 Kgf / ㎠. The method of claim 1, wherein the SPG membrane pore size is within the range of 2 ~ 10 ㎛. delete The method of claim 1, wherein the temperature of the monomer solution stream is in the range of 40 ~ 60 ℃. The method of claim 1, wherein the flow rate of the monomer solution stream is within the range of 0.1 ~ 10ml / min. The method of claim 1, wherein the flow rate of the solvent stream is in the range of 30 to 100 ml / min. The method of claim 1, wherein the monomer solution comprises carbon black, a wax, a monomer, a charge control agent, a dispersant, and an initiator. According to claim 1, wherein the monomer solution is carbon black 2 ~ 8 wt%, wax, 50 ~ 70 wt% monomer, 0.3 ~ 3 wt% charge control agent, 0.5 ~ 5 wt% dispersant and 4 ~ 7 wt% initiator Toner particles production method characterized in that. The method of claim 1, wherein the solvent is water. A toner particle produced by the method according to any one of claims 1, 2 and 4 to 9. 11. The toner particles of claim 10, wherein the toner particles have a dispersion degree of 1.0 or less.

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