JP2014091104A - Manufacturing method and manufacturing apparatus of particles and particles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide, as a toner manufacturing method based on the injection granulation method, a high-productivity manufacturing method of a toner for electrostatically charged image development capable of preventing toner adhesions to wall surfaces and concomitant coalescence of yet-to-be-solidified particles and accordingly having a sharp particle diameter distribution yielding a favorable image quality.SOLUTION: The provided manufacturing method of particles is comprising a droplet discharge step of discharging, as droplets, a particle composition liquid from at least one discharge orifice and a solidification step of solidifying the droplets, wherein the respective steps are executed within a container 61, walls of the container are at least partially constituted by air-permeable walls, and air flows streaming into the container from outside the container via the air-permeable walls are generated at the solidification step.

Description

  The present invention relates to a particle manufacturing method, a manufacturing apparatus, and particles. For example, the present invention relates to an electrostatic charge developing toner for developing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing and the like.

Conventionally, as a method for producing an electrostatic charge image developing toner used in a copying machine, a printer, a fax machine, and a composite machine based on an electrophotographic recording method, only a pulverization method has been used in recent years. The method of forming toner particles in an aqueous medium has been widely used, and is surpassing the pulverization method. The toner produced by the polymerization method is called “polymerized toner” or “chemical toner” in some countries.
The polymerization method is referred to as such because it involves the polymerization reaction of the toner raw material at the time of toner particle formation or in the process. Various polymerization methods have been put into practical use and include suspension polymerization, emulsion aggregation, polymer suspension (polymer aggregation), ester elongation reaction, and the like.

  In general, the toner obtained by the polymerization method is easier to obtain a smaller particle size, has a narrow particle size distribution, and has a nearly spherical shape compared to the toner obtained by the pulverization method. The image in is advantageous in that it is easy to obtain high image quality. However, on the other hand, it takes a long time for the polymerization process, and after completion of solidification, it is necessary to separate the solvent and toner particles, and then repeat washing and drying, which requires a lot of time, a lot of water and energy. There is.

  Therefore, there is known a jet granulation method in which a liquid in which a raw material component of toner is dissolved or dispersed in an organic solvent (hereinafter referred to as toner component liquid) is finely divided using various atomizers and then dried to obtain a powdery toner. (For example, refer to Patent Documents 1 to 3). According to this method, since it is not necessary to use water, steps such as washing and drying can be greatly reduced, so that the disadvantages of the polymerization method can be avoided.

  In the toner manufacturing methods disclosed in Patent Documents 1 to 3, droplets corresponding to the nozzle diameter are discharged from the nozzle. In this method, after the toner component liquid is sprayed, the droplets coalesce before the formed droplets are dried, and the solvent is dried in that state to obtain a toner, so that the resulting toner The particle size distribution was inevitably widened, and the particle size distribution was not satisfactory.

  In the toner manufacturing methods disclosed in Patent Documents 1 to 4, droplets corresponding to the nozzle diameter are discharged from the nozzle. In this method, the discharged droplets are dried and solidified in the gas phase and collected as solid fine particles. However, a part of the droplets adheres to the wall of the drying tower and is not collected so that production efficiency is not lowered. I can't. In addition, the coalesced particles once attached to the wall surface can be taken and collected, thereby deteriorating the particle size distribution of the collected particles, which limits the quality. Therefore, such a toner production method has not been satisfactory.

  Therefore, the present invention has been made in view of the above problems, and in the method for producing an electrostatic charge image developing toner by the jet granulation method, the adhesion of the droplets to the wall surface after spraying and the accompanying unsolidified particles. There is provided a method for producing a toner for developing an electrostatic charge image which prevents unification, and thus has high productivity and a narrow particle size distribution.

The features of the present invention as means for solving the above-described problems are as follows.
A method for producing particles, comprising: a droplet discharge step for discharging a particle composition liquid from at least one discharge hole to form droplets; and a solidification step for solidifying the droplets. And at least a part of the container wall of the container is made of a gas permeable wall, and in the solidification step, an air flow directed from the outside of the container to the inside of the container is generated through the gas permeable wall. Production method

The present invention, which is a means for solving the above problems, has the following specific effects.
By the method for producing particles according to the present invention, it is possible to prevent adhesion of droplets after spraying to the wall surface and coalescence of unsolidified particles, thereby providing a method for producing particles having high productivity and a narrow particle size distribution. Can do.

It is sectional drawing which shows the structure of a liquid column resonance droplet formation means. It is sectional drawing which shows the structure of a liquid column resonance droplet formation unit. It is sectional drawing of a discharge hole. It is the schematic which shows the standing wave of the speed and pressure fluctuation in the case of N = 1,2,3. It is the schematic which shows the standing wave of the speed and pressure fluctuation in the case of N = 4 and 5. It is the schematic which shows the mode of the liquid column resonance phenomenon which arises in the liquid column resonance flow path of a liquid column resonance droplet formation means. It is the schematic of the particle | grain manufacturing apparatus of this invention. It is a conceptual diagram which shows the method of preventing coalescence of the particle | grains after discharge. It is the schematic of the particle | grain manufacturing apparatus of this invention.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims. These changes and modifications are included in the scope of the claims, and the following description is an example of the best mode of the present invention and does not limit the scope of the claims.

  One example of the particle production means of the present invention will be described below with reference to FIGS. The particle production means of the present invention is divided into a droplet discharge means and a droplet solidification collecting means. Each is described below. In the following, the present invention will be described with reference to the case where the particles are toners, but the particles in the present invention are not limited to toners.

[Droplet discharge means]
The droplet discharge means used in the present invention is not particularly limited as long as the particle size distribution of the discharged droplets is narrow, and a known one can be used. Examples of the droplet discharge means include a one-fluid nozzle, a two-fluid nozzle, a membrane vibration type discharge means, a Rayleigh split type discharge means, a liquid vibration type discharge means, and a liquid column resonance type discharge means. A film vibration type droplet discharge means is described in, for example, Japanese Patent Application Laid-Open No. 2008-292976. A Rayleigh splitting type droplet discharge means is described in, for example, Japanese Patent No. 4647506. A liquid vibration type droplet discharge means is described in, for example, Japanese Patent Application Laid-Open No. 2010-102195.
In order to narrow the particle size distribution of the droplets and ensure the productivity of the toner, for example, liquid droplet resonance can be used. In droplet liquid column resonance, the liquid in the liquid column resonance liquid chamber is vibrated to form a standing wave by liquid column resonance, and from a plurality of discharge holes formed in the antinode of the standing wave. What is necessary is just to discharge a liquid.

[Liquid column resonance ejection means]
As an example of the droplet discharge means, a liquid column resonance type discharge means that discharges using resonance of the liquid column will be described.
FIG. 1 shows a liquid column resonance droplet discharge means 11. The liquid column resonance droplet discharge means 11 includes a liquid common supply path 17 and a liquid column resonance liquid chamber 18. The liquid column resonance liquid chamber 18 communicates with a liquid common supply path 17 provided on one of the wall surfaces at both ends in the longitudinal direction. Further, the liquid column resonance liquid chamber 18 is provided on a wall surface facing the discharge hole 19 and a discharge hole 19 for discharging the droplet 21 to one wall surface of the wall surfaces connected to both ends. Vibration generating means 20 for generating high-frequency vibrations to form standing waves. The vibration generating means 20 is connected to a high frequency power source (not shown).

  In the present invention, a liquid containing a component that forms particles is referred to as a particle composition liquid. The particle composition liquid is discharged from the discharge means and may be a liquid under the discharge conditions. That is, the component of the particle to be obtained may be dissolved or dispersed in a solvent, or the particle component may be melted without containing a solvent. (Hereinafter, these will be referred to as “toner component liquid” for the description of the case of producing toner.) The toner component liquid 14 is shown in FIG. 2 through a liquid supply pipe by a liquid circulation pump (not shown). It flows into the liquid common supply path 17 of the liquid column resonance droplet forming unit 10 and is supplied to the liquid column resonance liquid chamber 18 of the liquid column resonance droplet discharge means 11 shown in FIG. A pressure distribution is formed in the liquid column resonance liquid chamber 18 filled with the toner component liquid 14 by the liquid column resonance standing wave generated by the vibration generating means 20. Then, the droplet 21 is ejected from the ejection hole 19 arranged in a region where the amplitude of the liquid column resonance standing wave is large and the pressure fluctuation is large and which is an antinode of the standing wave. The region that becomes the antinode of the standing wave due to the liquid column resonance means a region other than the node of the standing wave. Preferably, it is a region where the pressure fluctuation of the standing wave has an amplitude large enough to discharge the liquid, and more preferably a position where the amplitude of the pressure standing wave becomes a maximum (a section as a velocity standing wave). ) To a minimum position in a range of ± 1/4 wavelength.

  If the region is an antinode of a standing wave, even if there are a plurality of discharge holes, substantially uniform droplets can be formed from each, and moreover, the droplets can be discharged efficiently. And clogging of the discharge holes is less likely to occur. The toner component liquid 14 that has passed through the liquid common supply path 17 flows through a liquid return pipe (not shown) and is returned to the raw material container. When the amount of the toner component liquid 14 in the liquid column resonance liquid chamber 18 decreases due to the discharge of the liquid droplets 21, the suction force due to the action of the liquid column resonance standing wave in the liquid column resonance liquid chamber 18 acts to supply the common liquid. The flow rate of the toner component liquid 14 supplied from the path 17 increases. Then, the toner component liquid 14 is replenished into the liquid column resonance liquid chamber 18. When the toner component liquid 14 is replenished in the liquid column resonance liquid chamber 18, the flow rate of the toner component liquid 14 passing through the liquid common supply path 17 is restored.

  Each of the liquid column resonance liquid chambers 18 in the liquid column resonance droplet discharge means 11 has a frame formed of a material having such a high rigidity that does not affect the resonance frequency of the liquid at a driving frequency such as metal, ceramics, or silicon. It is formed by bonding. Further, as shown in FIG. 1, the length L between the wall surfaces at both ends in the longitudinal direction of the liquid column resonance liquid chamber 18 is determined based on the liquid column resonance principle as described later. Further, the width W of the liquid column resonance liquid chamber 18 shown in FIG. 2 is desirably smaller than one half of the length L of the liquid column resonance liquid chamber 18 so as not to give an extra frequency to the liquid column resonance. . Furthermore, it is preferable that a plurality of liquid column resonance liquid chambers 18 are arranged for one droplet forming unit 10 in order to dramatically improve productivity. The range is not limited, but one droplet forming unit provided with 100 to 2000 liquid column resonance liquid chambers 18 is most preferable because both operability and productivity can be achieved. In addition, for each liquid column resonance liquid chamber, a flow path for supplying liquid is connected from the common liquid supply path 17, and the common liquid supply path 17 communicates with a plurality of liquid column resonance liquid chambers 18. .

Further, the vibration generating means 20 in the liquid column resonance droplet discharging means 11 is not particularly limited as long as it can be driven at a predetermined frequency, but a form in which a piezoelectric body is bonded to the elastic plate 9 is desirable. The elastic plate constitutes a part of the wall of the liquid column resonance liquid chamber so that the piezoelectric body does not come into contact with the liquid. Examples of the piezoelectric body include piezoelectric ceramics such as lead zirconate titanate (PZT). However, since the amount of displacement is generally small, the piezoelectric body is often used by being laminated. In addition, piezoelectric polymers such as polyvinylidene fluoride (PVDF), single crystals such as quartz, LiNbO ₃ , LiTaO ₃ , and KNbO ₃ can be used. Furthermore, it is desirable that the vibration generating means 20 is arranged so that it can be individually controlled for each liquid column resonance liquid chamber. In addition, the block-shaped vibrating member made of one material is partially cut in accordance with the arrangement of the liquid column resonance liquid chambers, and each liquid column resonance liquid chamber can be individually controlled via an elastic plate. desirable.

  Furthermore, the diameter of the opening of the discharge hole 19 is desirably in the range of 1 [μm] to 40 [μm]. By being 1 [μm] or more, it is possible to prevent the droplets from becoming too small and to form droplets of an appropriate size. Further, even in the case where a solid particle such as a pigment is contained as a constituent component of the toner, the discharge hole 19 is not clogged and productivity can be improved. Moreover, it can prevent that the diameter of a droplet becomes large too much because it is 40 [micrometers] or less. As a result, the toner composition liquid can be dried and solidified without significantly diluting to obtain a desired toner particle diameter of 3 to 6 μm. It may be necessary to dilute the toner composition to a very dilute solution with an organic solvent, which can reduce the amount of organic solvent used for dilution and reduce the drying energy required to obtain a certain amount of toner. Can do. Further, as can be seen from FIG. 2, adopting a configuration in which the discharge holes 19 are provided in the width direction in the liquid column resonance liquid chamber 18 can provide a large number of openings of the discharge holes 19, thereby increasing the production efficiency. Therefore, it is preferable. Further, since the liquid column resonance frequency varies depending on the arrangement of the discharge holes 19, it is desirable to appropriately determine the liquid column resonance frequency after confirming the discharge of the droplet.

The sectional shape of the discharge hole 19 is described as a tapered shape in which the diameter of the opening is reduced in FIG. 1 and the like, but the sectional shape can be appropriately selected.
FIG. 3 shows a cross-sectional shape that the discharge hole 19 can take. (A) has a shape in which the opening diameter becomes narrow while having a round shape from the liquid contact surface of the discharge hole 19 toward the discharge port, and near the outlet of the discharge hole 19 when the thin film 41 vibrates. Since the pressure applied to the liquid is maximized, it is the most preferable shape for stabilizing the discharge.

(B) has a shape in which the opening diameter becomes narrower from the liquid contact surface of the discharge hole 19 toward the discharge port, and the nozzle angle 24 can be appropriately changed. The pressure applied to the liquid can be increased in the vicinity of the outlet of the discharge hole 19 when the thin film 41 vibrates by this nozzle angle similar to (a), but the range is preferably 60 ° to 90 °. By setting the angle to 60 ° or more, a sufficient pressure can be applied to the liquid, and the thin film 41 can be easily processed. When the nozzle angle 24 is 90 °, (c) corresponds. However, by setting the maximum value to 90 °, it is not difficult to apply pressure to the outlet, so that droplet discharge is stabilized.
(D) is a shape combining (a) and (b). In this way, the shape may be changed step by step.

Next, the mechanism of droplet formation by the droplet formation unit in liquid column resonance will be described.
First, the principle of the liquid column resonance phenomenon that occurs in the liquid column resonance liquid chamber 18 in the liquid column resonance droplet discharge means 11 of FIG. 1 will be described.
When the sound velocity of the toner component liquid in the liquid column resonance liquid chamber is c, and the driving frequency given to the toner component liquid as a medium from the vibration generating unit 20 is f, the wavelength λ at which the liquid resonance occurs is
λ = c / f (Formula 1)
Are in a relationship.

In the liquid column resonance liquid chamber 18 of FIG. 1, the length from the end of the frame on the fixed end side to the end on the liquid common supply path 17 side is L. The height h1 (= about 80 [μm]) of the end of the frame on the liquid common supply path 17 side is about twice the height h2 (= about 40 [μm]) of the communication port, and the end is closed. It is equivalent to the fixed end. In the case of such fixed ends on both sides, resonance is formed most efficiently when the length L matches an even multiple of one-fourth of the wavelength λ. That is, it is expressed by the following formula 2.
L = (N / 4) λ (Expression 2)
(However, N is an even number.)

Furthermore, the above formula 2 is also established in the case of a double-sided open end where both ends are completely open.
Similarly, when one side is equivalent to an open end having a pressure relief portion and the other side is closed (fixed end), that is, one side fixed end or one side open end, the length L is the wavelength λ. Resonance is most efficiently formed when it matches an odd multiple of a quarter. That is, N in Expression 2 is expressed as an odd number.

The most efficient drive frequency f is obtained from the above formula 1 and the above formula 2.
f = N × c / (4L) (Formula 3)
It is guided. However, in reality, since the liquid has a viscosity that attenuates the resonance, the vibration is not amplified infinitely, and has a Q value. As shown in equations 4 and 5, which will be described later, Resonance also occurs at frequencies near the highly efficient drive frequency f.

  FIG. 4 shows the shape of the standing wave of velocity and pressure fluctuation (resonance mode) when N = 1, 2, and 3. FIG. 5 shows the standing wave of velocity and pressure fluctuation when N = 4, 5. The shape (resonance mode) is shown. Originally, it is a dense wave (longitudinal wave), but it is generally expressed as shown in FIGS. The solid line is the velocity standing wave, and the dotted line is the pressure standing wave. For example, as can be seen from FIG. 4 (a) showing the case of a fixed end with N = 1, in the case of velocity distribution, the amplitude of the velocity distribution becomes zero at the closed end, and the amplitude becomes maximum at the open end. Easy to understand. When the length between both ends in the longitudinal direction of the liquid column resonance liquid chamber is L, the wavelength at which the liquid resonates is λ, and the standing wave is most efficiently generated when the integer N is 1 to 5. . In addition, since the standing wave pattern varies depending on the open / closed state of both ends, they are also shown. As will be described later, the condition of the end is determined by the state of the opening of the discharge hole and the opening of the supply side.

In acoustics, the open end is an end where the moving speed of the medium (liquid) in the longitudinal direction becomes maximum, and conversely, the pressure becomes minimum. Conversely, the closed end is defined as an end where the moving speed of the medium becomes zero. The closed end is considered as an acoustically hard wall and wave reflection occurs. When ideally completely closed or open, a resonant standing wave of the form shown in FIGS. 4 and 5 is generated by superposition of the waves. However, the standing wave pattern varies depending on the number of ejection holes and the opening position of the ejection holes, and a resonance frequency appears at a position deviated from the position obtained from the above equation 3. In this case, stable ejection conditions can be created by appropriately adjusting the drive frequency.
For example, the sound velocity c of the liquid is 1,200 [m / s], the length L of the liquid column resonance liquid chamber is 1.85 [mm], wall surfaces exist at both ends, and it is completely equivalent to the fixed ends on both sides. When N = 2 resonance mode is used, the most efficient resonance frequency is derived as 324 kHz from the above equation (3). In another example, the sound speed c of the liquid is 1,200 [m / s], the length L of the liquid column resonance liquid chamber is 1.85 [mm], and the same conditions as described above are used. When N = 4 resonance mode equivalent to the fixed end is used, the most efficient resonance frequency is derived from Equation 3 as 648 kHz. Thus, higher-order resonance can be used also in the liquid column resonance liquid chamber having the same configuration.

  The liquid column resonance liquid chamber in the liquid column resonance droplet discharge means 11 shown in FIG. 1 is an end that can be described as an acoustically soft wall due to the influence of the opening of the discharge hole or whether both ends are equivalent to the closed end state. Although it is preferable to increase the frequency, it is not limited to this and may be an open end. The influence of the opening of the discharge hole here means that the acoustic impedance is reduced, and in particular, the compliance component is increased. Therefore, the configuration in which the wall surfaces are formed at both ends in the longitudinal direction of the liquid column resonance liquid chamber as shown in FIG. 4B and FIG. 5A is regarded as the resonance mode at both fixed ends and the discharge hole side as an opening. This is a preferred configuration because all resonance modes at one open end can be used.

  In addition, the numerical aperture of the discharge holes, the opening arrangement position, and the cross-sectional shape of the discharge holes are factors that determine the drive frequency, and the drive frequency can be appropriately determined accordingly. For example, when the number of ejection holes is increased, the restriction at the tip of the liquid column resonance liquid chamber, which has been the fixed end, gradually loosens, a resonance standing wave that is almost close to the open end is generated, and the drive frequency increases. In addition, the opening position of the discharge hole that is closest to the liquid supply path is the starting point, and it becomes a loose constraint condition. The cross-sectional shape of the discharge hole is round, or the volume of the discharge hole varies depending on the thickness of the frame. The upper standing wave has a short wavelength and is higher than the driving frequency. When a voltage is applied to the vibration generating means at the drive frequency determined in this way, the vibration generating means is deformed, and a resonant standing wave is generated most efficiently at the drive frequency. Further, the liquid column resonance standing wave is generated even at a frequency in the vicinity of the drive frequency at which the resonance standing wave is generated most efficiently. That is, the length between both ends in the longitudinal direction of the liquid column resonance liquid chamber is L, and the distance to the discharge hole closest to the end on the liquid supply side is Le. At this time, the vibration generating means is vibrated using a drive waveform mainly composed of the drive frequency f in the range determined by the following formulas 4 and 5 using the lengths of both L and Le, and liquid column resonance is performed. It is possible to induce and discharge a droplet from the discharge hole.

N × c / (4L) ≦ f ≦ N × c / (4Le) (Formula 4)
N × c / (4L) ≦ f ≦ (N + 1) × c / (4Le) (Formula 5)

  The ratio of the length L between both ends in the longitudinal direction of the liquid column resonance liquid chamber to the distance Le to the discharge hole closest to the end on the liquid supply side is preferably Le / L> 0.6.

  A liquid column resonance pressure standing wave is formed in the liquid column resonance liquid chamber 18 of FIG. 1 using the principle of the liquid column resonance phenomenon described above, and the discharge holes 19 arranged in a part of the liquid column resonance liquid chamber 18. In this case, droplet discharge occurs continuously. Note that it is preferable to dispose the discharge hole 19 at a position where the pressure of the standing wave fluctuates the most, since the discharge efficiency is increased and the driving can be performed with a low voltage. Further, one discharge hole 19 may be provided for one liquid column resonance liquid chamber 18, but it is preferable to arrange a plurality of discharge holes 19 from the viewpoint of productivity. Specifically, it is preferably between 2 and 100.

  By setting the number to 100 or less, the voltage applied to the vibration generating means 20 when a desired droplet is formed from the ejection hole 19 can be kept low, and the behavior of the piezoelectric body as the vibration generating means 20 can be stabilized. it can. When the plurality of discharge holes 19 are opened, the pitch between the discharge holes is preferably 20 [μm] or more and not more than the length of the liquid column resonance liquid chamber. By setting the pitch between the discharge holes to 20 [μm] or more, it is possible to reduce the probability that droplets discharged from adjacent discharge holes collide with each other to form large droplets, and the toner particle size distribution is good. Can be.

  Next, the state of the liquid column resonance phenomenon occurring in the liquid column resonance liquid chamber in the droplet discharge head in the droplet forming unit will be described with reference to FIG. In the figure, the solid line drawn in the liquid column resonance liquid chamber represents the velocity distribution plotting the velocity at any measurement position from the fixed end side to the liquid common supply path side end in the liquid column resonance liquid chamber. The direction from the common liquid supply path to the liquid column resonance liquid chamber is +, and the opposite direction is −. In addition, the dotted line marked in the liquid column resonance liquid chamber indicates a pressure distribution in which the pressure value at each arbitrary measurement position between the fixed end side and the liquid common supply path side end in the liquid column resonance liquid chamber is plotted. The positive pressure is + with respect to the atmospheric pressure, and the negative pressure is-. Moreover, if it is a positive pressure, a pressure will be applied to the downward direction in the figure, and if it is a negative pressure, a pressure will be applied to the upward direction in the figure. Further, in the same figure, the liquid common supply path side is opened as described above, but the height of the opening where the liquid common supply path 17 and the liquid column resonance liquid chamber 18 communicate (height h2 shown in FIG. 1). The height of the frame serving as the fixed end (height h1 shown in FIG. 1) is about twice or more as compared to. Therefore, FIG. 6 shows temporal changes in the velocity distribution and the pressure distribution under the approximate condition that the liquid column resonance liquid chamber 18 is substantially fixed on both sides.

FIG. 6A shows a pressure waveform and a velocity waveform in the liquid column resonance liquid chamber 18 when droplets are discharged.
In FIG. 6B, the meniscus pressure increases again after the liquid is drawn immediately after the droplet is discharged. As shown in FIGS. 4A and 4B, the pressure in the flow path provided with the discharge hole 19 in the liquid column resonance liquid chamber 18 is maximum. Thereafter, as shown in FIG. 6C, the positive pressure in the vicinity of the ejection hole 19 decreases, and the liquid droplet 21 is ejected in a negative pressure direction.

  Then, as shown in FIG. 6D, the pressure in the vicinity of the discharge hole 19 is minimized. From this time, filling of the liquid component resonance liquid chamber 18 with the toner component liquid 14 starts. Thereafter, as shown in FIG. 6E, the negative pressure in the vicinity of the discharge hole 19 becomes smaller and shifts to the positive pressure direction. At this time, the filling of the toner component liquid 14 is completed. Then, as shown in FIG. 6A again, the positive pressure in the droplet discharge region of the liquid column resonance liquid chamber 18 becomes maximum, and the droplet 21 is discharged from the discharge hole 19. As described above, a standing wave due to liquid column resonance is generated in the liquid column resonance liquid chamber by high-frequency driving of the vibration generating means. And since the discharge hole 19 is arrange | positioned in the droplet discharge area | region corresponded to the antinode of the standing wave by liquid column resonance which becomes a position where a pressure fluctuates the most, the droplet 21 corresponds to the period of the antinode. The ink is continuously discharged from the discharge hole 19.

[Droplet solidification]
The particles (toner) of the present invention can be obtained by solidifying the droplets of the toner component liquid ejected into the gas from the droplet ejection means described above and then collecting it.

[Droplet solidification means]
In order to solidify the liquid droplets, the concept varies depending on the properties of the toner component liquid, but basically any means can be used as long as the toner component liquid can be brought into a solid state.
For example, if the toner component liquid is obtained by dissolving or dispersing a solid raw material in a volatile solvent, this can be achieved by drying the droplets in a conveying airflow after the droplets are jetted, that is, volatilizing the solvent. . In drying the solvent, the drying state can be adjusted by appropriately selecting the temperature, vapor pressure, gas type, and the like of the gas to be injected. Further, even if the inside is not completely dried, additional collection may be performed in a separate step after collection as long as the collected particles maintain a solid state. Even if it does not follow the said example, you may achieve by application of a temperature change, a chemical reaction, etc.
However, since the toner production efficiency and the quality of the toner itself are affected by the drying method, this is a very important process requiring attention. The realization of high production efficiency, which is the point of the present invention, and the realization of high-quality toner production from the viewpoint of particle size distribution will be described.

  The droplets released by the discharge fixation are carried by the carrier airflow and solidify due to volatilization, temperature drop, etc., but some of them adhere to the wall surface of the drying tower. Although the cause of the adhesion varies depending on the case, in addition to natural diffusion due to Brownian motion or the like, wall surface charging, particle charging, and turbulence of the air flow due to the shape of the flow path are considered. Since the adhered particles are not collected, the productivity is lowered accordingly, which is not preferable. Also, some of the particles that adhere are not completely dried even on the surface, and these coalesce with other particles. In addition, it causes further particle adhesion. Since the adhered particles do not always remain attached to the wall surface, some of the particles are peeled off and are transported again to the carrier airflow and collected. Since these particles include coalesced particles, the particle size distribution of the collected particles is deteriorated, thus reducing the quality.

As one of the countermeasures for the above phenomenon, it is conceivable to accelerate the solidification, but it is more effective if adhesion does not occur. In the present invention, as a method for minimizing the adhesion of the drying tower wall surface, it is proposed to generate an air flow from the wall surface. If there is a sufficient counter airflow for the particles moving toward the wall surface, it will not be possible to reach the wall surface, so no adhesion will occur. In order to generate the opposite airflow, it is preferable that the wall surface of the drying tower be a breathable wall. It is ideal if the entire wall surface (see FIG. 7) is an air permeable wall, but it is also effective to use part of the wall surface (see FIG. 9) as an air permeable wall. When only a part of the wall surface is a gas permeable wall, it is preferable that the gas permeable wall is a portion where the adhesion of unsolidified particles immediately after ejection is the largest. By simply making the container wall of the container (drying tower) a gas permeable wall, the inside of the drying tower becomes negative with respect to the outside due to suction of the particle collecting part, so that airflow flows through the wall surface (see FIG. 7). . However, it is also possible to generate an opposing airflow by pushing pressurized gas from the outside of the drying tower through the air-permeable wall (see FIG. 9). Inside the drying tower, this airflow acts as a force that opposes the particles going to the wall surface, preventing adhesion. The counter airflow depends on the pressure loss of the air permeable wall and the suction force of the collection part, or the pressure of the externally pressurized gas, but the more the airflow, the more effective as long as it does not adversely affect the airflow of the discharged droplets. Is. The counter airflow preferably flows from the outside to the inside of the container and is an airflow perpendicular to the wall surface of the container, but may be an airflow that can prevent the particles from adhering to the wall surface inside the container. Since this airflow is weak with respect to the conveyance airflow inside the container, it merges inside the container and flows downward.
Examples of the material of the air-permeable wall include porous plates made of metal or alloy, porous materials such as ceramics and sintered metal.
Examples to be described later show the effects of the present invention described above.

[Solidification particle collection means]
The solidified particles can be recovered from the air by a known powder collecting means such as cyclone collecting or a back filter.

FIG. 7 is a cross-sectional view of an example of an apparatus (toner manufacturing apparatus) that implements the particle manufacturing method of the present invention. The toner manufacturing apparatus 1 mainly includes a droplet discharge means 2 and a dry collection unit 60.
A raw material container 13 for storing the toner component liquid 14 and a liquid circulation pump 15 are connected to the droplet discharge means 2 so that the toner component liquid 14 can be supplied to the droplet discharge means 2 at any time. This liquid circulation pump 15 supplies the toner component liquid 14 accommodated in the raw material container 13 to the droplet discharge means 2 through the liquid supply pipe 16 and further returns to the raw material container 13 through the liquid return pipe 22. The toner component liquid 14 in the liquid supply pipe 16 is pumped. The liquid supply pipe 16 is provided with a pressure measuring device P1 and the dry collection unit is provided with a pressure measuring device P2. Managed by. At this time, if the relationship of P1> P2, the toner component liquid 14 may ooze out from the hole 12, and if P1 <P2, there is a risk that gas enters the discharge means and the discharge stops. It is desirable that P1≈P2.
In the chamber 61, a descending airflow (conveyance airflow 101) created from the conveyance airflow inlet 64 is formed. The droplets 21 discharged from the droplet discharge means 2 are transported downward not only by gravity but also by the transport airflow 101 and are collected by the solidified particle collecting means 62.

[Conveyance airflow]
When the ejected droplets come into contact with each other before drying, the droplets coalesce and become one particle (hereinafter, this phenomenon is called coalescence). In order to obtain solidified particles having a uniform particle size distribution, it is necessary to maintain the distance between the ejected droplets. However, the ejected droplets have a constant initial velocity, but eventually become stalled due to air resistance. The jetted droplets catch up with the stalled particles and coalesce as a result. Since this phenomenon occurs constantly, the particle size distribution is greatly deteriorated when the particles are collected. In order to prevent coalescence, it is necessary to transport the liquid droplets while solidifying the droplets while preventing the liquid droplets from decreasing in speed and preventing the liquid droplets from coming into contact with each other while preventing the coalescence. Carry the solidified particles to the collection means.
For example, as shown in FIG. 1, a part of the transport airflow 101 is arranged as a first airflow in the vicinity of the droplet discharge means in the same direction as the droplet discharge direction, thereby reducing the droplet velocity immediately after the droplet discharge. Can be prevented and coalescence can be prevented. Alternatively, as shown in FIG. 8, the direction may be transverse to the ejection direction. Alternatively, although not shown, it may have an angle, and it is desirable to have an angle at which the droplets are separated from the droplet discharge means. As shown in FIG. 8, when the anti-adhesion airflow is applied from the lateral direction to the droplet discharge, it is desirable that the trajectories do not overlap when the droplets are conveyed by the anti-adhesion airflow from the discharge port. .
After preventing coalescence by the first air stream as described above, the solidified particles may be carried to the solidified particle collecting means by the second air stream.

It is desirable that the velocity of the first air flow is equal to or higher than the droplet jet velocity. If the speed of the anti-adhesion airflow is lower than the droplet ejection speed, it is difficult to exert the function of preventing the droplet particles, which is the original purpose of the anti-adhesion airflow, from contacting.
The property of the first air stream can be added with a condition such that the droplets do not coalesce with each other, and may not necessarily be the same as the second air stream. Further, a chemical substance that promotes solidification of the particle surface may be mixed in the anti-adhesion airflow, or may be imparted with the expectation of physical action.

  The carrier airflow 101 is not particularly limited as a state of the airflow, and may be a laminar flow, a swirl flow, or a turbulent flow. There is no particular limitation on the type of gas constituting the carrier airflow 101, and air or a nonflammable gas such as nitrogen may be used. Moreover, the temperature of the conveyance airflow 101 can be adjusted as appropriate, and it is desirable that there is no fluctuation during production. Also, means for changing the airflow state of the carrier airflow 101 in the chamber 61 may be taken. The carrier airflow 101 may be used not only to prevent the droplets 21 from being attached to each other but also to prevent them from adhering to the chamber 61.

[Secondary drying]
When the amount of residual solvent contained in the toner particles obtained by the dry collecting means shown in FIG. 7 is large, secondary drying is performed as necessary to reduce this. As the secondary drying, general known drying means such as fluidized bed drying or vacuum drying can be used. If the organic solvent remains in the toner, not only the toner characteristics such as heat-resistant storage stability, fixing properties, and charging characteristics will change over time. Since the organic solvent volatilizes during fixing by heating, the possibility of adverse effects on the user and peripheral equipment is increased. Therefore, sufficient drying is performed.

Next, the toner will be described.
The toner obtained by the present invention contains at least a resin, a colorant, and a wax, and optionally contains a charge adjusting agent, an additive, and other components.

The “toner component liquid” that can be used in the present invention will be described. The toner component liquid may be in a liquid state in which the toner component is dissolved or dispersed in a solvent, or may be free from a solvent as long as it is liquid under the conditions of ejection, and a part or all of the toner component is in a molten state. In a liquid state.
As the toner material, if the toner component liquid described above can be adjusted, the same material as the conventional electrophotographic toner can be used. As described above, the droplets are made into fine droplets by the droplet discharge means, and the target toner particles can be produced by the droplet solidification collecting means.

〔resin〕
Examples of the resin include at least a binder resin.
The binder resin is not particularly limited, and a commonly used resin can be appropriately selected and used. Examples of the binder resin include vinyl polymers such as styrene monomers, acrylic monomers, and methacrylic monomers, copolymers of these monomers or two or more types, and polyester polymers. Polyol resin, phenol resin, silicone resin, polyurethane resin, polyamide resin, furan resin, epoxy resin, xylene resin, terpene resin, coumarone indene resin, polycarbonate resin, petroleum resin, and the like.

As the properties of the binder resin, it is desirable that the binder resin be dissolved in a solvent.
[Molecular weight distribution of binder resin]
The molecular weight distribution of the binder resin by GPC (gel permeation chromatography) preferably has at least one peak in the region of a molecular weight of 3,000 to 50,000 in terms of toner fixing properties and offset resistance. In addition, as a THF soluble component, a binder resin in which a component having a molecular weight of 100,000 or less is 60 to 100 [%] is preferable, and a binder having at least one peak in a region having a molecular weight of 5,000 to 20,000. A resin is more preferable.

[Acid value of binder resin]
What has 60 [mass%] or more of resin whose acid value of binder resin has 0.1-50 [mgKOH / g] is preferable.
In the present invention, the acid value of the binder resin component of the toner composition is measured according to JIS K-0070.

[Magnetic material]
As the magnetic material that can be used in the present invention, known magnetic materials conventionally used for electrophotographic toners can be used. Examples of magnetic materials include (1) iron oxide containing magnetic iron oxide such as magnetite, maghemite, and ferrite, and other metal oxides, and (2) metals such as iron, cobalt, nickel, or these metals. Alloys with metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, (3) and mixtures thereof Used. The magnetic material can also be used as a colorant. As the usage-amount of the said magnetic body, 10-200 mass parts of magnetic bodies are preferable with respect to 100 mass parts of binder resin, and 20-150 mass parts is more preferable. The number average particle diameter of these magnetic materials is preferably 0.1 to 2 [μm], more preferably 0.1 to 0.5 [μm]. The number average diameter can be obtained by measuring a photograph taken with a transmission electron microscope with a digitizer or the like.

[Colorant]
The colorant is not particularly limited, and a commonly used resin can be appropriately selected and used.
The content of the colorant is preferably 1 to 15 [% by mass] and more preferably 3 to 10 [% by mass] based on the toner.

The colorant used in the toner obtained by the present invention can also be used as a master batch combined with a resin. The master batch is for dispersing the pigment in advance, and may not be used if sufficient dispersion of the pigment is obtained. In general, a master batch is obtained by dispersing a pigment in hardness in a resin by applying high shear to the pigment and the resin. A conventionally well-known thing can be used as binder resin knead | mixed with manufacture of a masterbatch or a masterbatch. These may be used individually by 1 type, and 2 or more types may be mixed and used for them.
As the usage-amount of the said masterbatch, 0.1-20 mass parts is preferable with respect to 100 mass parts of binder resin.

  A dispersant may be used to increase the dispersibility of the pigment during the production of the masterbatch. The dispersant is preferably highly compatible with the binder resin in terms of pigment dispersibility. Conventionally known dispersants can be used. Specific examples of commercially available products include “Ajisper PB821”, “Azisper PB822” (manufactured by Ajinomoto Fine-Techno Co., Ltd.), “Disperbyk-2001” (manufactured by BYK Chemie), “EFKA-4010”. (Made by EFKA) and the like.

The dispersant is preferably blended in the toner at a ratio of 0.1 to 10 [mass%] with respect to the colorant. When the blending ratio is 0.1 [mass%] or more, sufficient pigment dispersibility is obtained, and when it is 10 [mass%] or less, a decrease in chargeability under high humidity can be prevented.
The addition amount of the dispersant is preferably 1 to 200 parts by mass, more preferably 5 to 80 parts by mass with respect to 100 parts by mass of the colorant. When the amount is 1 part by mass or more, sufficient dispersibility is obtained, and when the amount is 200 parts by mass or less, good chargeability is obtained.

<Wax>
The toner component liquid that can be used in the present invention contains a wax together with a binder resin and a colorant.
There is no restriction | limiting in particular as wax, What is normally used can be selected suitably and can be used. Examples of the wax include aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, polyolefin wax, microcrystalline wax, paraffin wax and sazol wax, and aliphatic hydrocarbon waxes such as oxidized polyethylene wax. Or block copolymers thereof, plant waxes such as candelilla wax, carnauba wax, wood wax, jojoba wax, animal waxes such as beeswax, lanolin, spermaceti, mineral waxes such as ozokerite, ceresin, and petrolatum, montan Examples thereof include waxes mainly composed of fatty acid esters such as acid ester wax and caster wax, and those obtained by partially or fully deoxidizing fatty acid esters such as deoxidized carnauba wax.

The melting point of the wax is preferably 70 to 140 [° C.] and more preferably 70 to 120 [° C.] in order to balance the fixability and the offset resistance. Sufficient blocking resistance is obtained when the temperature is 70 [° C.] or higher, and a good offset resistance effect is exhibited when the temperature is 140 [° C.] or lower.
The total content of the wax is preferably 0.2 to 20 parts by mass and more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

  In the present invention, the temperature of the peak top of the endothermic peak of the wax measured by DSC (Differential Scanning Calorimetry) is defined as the melting point of the wax.

  The wax or toner DSC measuring device is preferably measured with a high-precision internal heat input compensation type differential scanning calorimeter. As a measuring method, it carries out according to ASTM D3418-82. The DSC curve used in the present invention is one that is measured when the temperature is raised at a temperature rate of 10 [° C./min] after raising and lowering the temperature once and taking a previous history.

  The toner obtained by the present invention is used for the purpose of protecting the electrostatic latent image carrier / carrier, improving the cleaning property, adjusting the thermal characteristics / electrical characteristics / physical characteristics, adjusting the resistance, adjusting the softening point, and improving the fixing rate. Additives can be used. The additives include various metal soaps, fluorine-based surfactants, dioctyl phthalate, and conductive additives such as tin oxide, zinc oxide, carbon black, antimony oxide, and inorganic fine powders such as titanium oxide, aluminum oxide, and alumina. Examples include the body. These inorganic fine powders may be hydrophobized as necessary. In addition, lubricants such as polytetrafluoroethylene, zinc stearate, polyvinylidene fluoride, abrasives such as cesium oxide, silicon carbide, strontium titanate, anti-caking agents, white particles and black particles having opposite polarity to the toner particles, Can also be used in small amounts as a developability improver.

  These additives have a silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, and other organosilicons for the purpose of charge control and the like. It is also preferable to treat with a treating agent such as a compound or various treating agents.

  As the additive, inorganic fine particles can be preferably used. As said inorganic fine particle, well-known things, such as a silica, an alumina, a titanium oxide, can be used, for example.

  In addition, polymer fine particles, such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, methacrylate esters, acrylate copolymers, polycondensation systems such as silicone, benzoguanamine, and nylon, thermosetting Examples thereof include polymer particles made of a resin.

  Such an external additive can be made hydrophobic by the surface treatment agent and prevent deterioration of the external additive itself even under high humidity. Examples of the surface treatment agent include a silane coupling agent, a silylating agent, a silane coupling agent having a fluorinated alkyl group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, a modified silicone oil, Etc. are preferable.

The primary particle diameter of the external additive is preferably 5 [nm] to 2 [μm], and more preferably 5 [nm] to 500 [nm]. Moreover, as a specific surface area by BET method, it is preferable that it is 20-500 [m < ² > / g]. The use ratio of the inorganic fine particles is preferably 0.01 to 5 [% by weight] of the toner, and more preferably 0.01 to 2.0 [% by weight].

A cleaning property improver can be used to remove the developer after transfer remaining on the electrostatic latent image carrier or the primary transfer medium. Examples of the cleaning property improver include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles, polystyrene fine particles, and the like. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 [μm].
With the particle production method and production apparatus of the present invention, the particle recovery rate can be 70% or more. Moreover, the particle size distribution (weight average particle size / number average particle size) of the obtained particles may be 1.15 or less.

  Examples of the present invention are shown below, but the scope of the present invention is not limited by these Examples. The “parts” shown below represent parts by mass.

First, the formulation of the dissolution or dispersion used in the examples is shown.
The injection conditions are as described later.
-Preparation of colorant dispersion-
First, a carbon black dispersion as a colorant was prepared.
17 parts by mass of carbon black (Rega L400; manufactured by Cabot) and 3 parts by mass of a pigment dispersant were primarily dispersed in 80 parts by mass of ethyl acetate using a mixer having stirring blades. As the pigment dispersant, Ajisper PB821 (manufactured by Ajinomoto Fine Techno Co., Ltd.) was used. The obtained primary dispersion was finely dispersed by a strong shearing force using a bead mill (LMZ type manufactured by Ashizawa Finetech Co., Ltd., zirconia bead diameter 0.3 mm) to completely remove aggregates of 5 μm or more. Was prepared.

-Preparation of wax dispersion-
Next, a wax dispersion was prepared.
18 parts by mass of carnauba wax and 2 parts by mass of a wax dispersant were primarily dispersed in 80 parts by mass of ethyl acetate using a mixer having stirring blades. The primary dispersion was heated to 80 ° C. with stirring to dissolve the carnauba wax, and then the liquid temperature was lowered to room temperature to precipitate wax particles so that the maximum diameter was 3 μm or less. As the wax dispersant, a polyethylene wax grafted with a styrene-butyl acrylate copolymer was used. The obtained dispersion was further finely dispersed by a strong shearing force using a bead mill (LMZ type manufactured by Ashizawa Finetech Co., Ltd., zirconia bead diameter 0.3 mm), and the maximum diameter was adjusted to 1 μm or less.

-Preparation of dissolution or dispersion-
Next, a toner component liquid having the following composition to which a resin as a binder resin, the colorant dispersion, and the wax dispersion were added was prepared.
100 parts by weight of a polyester resin as a binder resin, 30 parts by weight of the colorant dispersion, 30 parts by weight of the wax dispersion, 840 parts by weight of ethyl acetate, and stirring for 10 minutes using a mixer having stirring blades, Evenly dispersed. Pigments and wax particles did not aggregate due to shock due to solvent dilution.

-Toner production equipment-
A particle manufacturing apparatus (toner manufacturing apparatus 1) having the configuration shown in FIG. 7 was used. The particle manufacturing apparatus includes a droplet discharge unit that discharges a particle composition liquid from at least one discharge hole to form droplets, and a solidification unit that solidifies the discharged droplets. The droplet discharge stage and the solidifying means are accommodated in the container.
Describe the size and conditions of each component.
-Liquid column resonance droplet discharge means-
The length L between both ends in the longitudinal direction of the liquid column resonance liquid chamber 18 is 1.85 [mm], N = 2 resonance mode, and the first to fourth discharge holes are N = 2 mode pressure standing. The thing which has arrange | positioned the discharge hole in the position of the antinode of the wave was used. The particle composition liquid is discharged from the discharge holes to form droplets. The drive signal generation source was a NF company function generator WF 1973, which was connected to the vibration generation means with a polyethylene-coated lead wire. The driving frequency at this time is 340 [kHz] according to the liquid resonance frequency.

-Toner collection part-
The chamber 61 (drying tower) as the container has an inner diameter of φ400 mm and a height of 2000 mm and is fixed vertically, the upper end and the lower end are squeezed, and the diameter of the carrier air flow inlet is φ50 mm, The diameter of the carrier airflow outlet is φ50 mm. In the chamber 61, the droplets discharged from the discharge holes are solidified. The inlet, upper end, lower end, and outlet of the chamber 61 were stainless steel walls that were not open. The cylindrical portion in the middle part of the chamber 61 utilized two kinds of breathable walls (a ceramic material which is a porous material and a brass material which is a metal porous plate). For comparison, a stainless steel wall surface that was not opened was used. The droplet discharge means 2 is disposed at the center of the chamber 61 at a height of 300 mm from the upper end in the chamber 61. The carrier airflow was 10.0 m / s and 40 ° C. nitrogen at the position of the droplet discharge means 2.

-Opposite airflow generation method-
As described above, in the present invention, at least a part of the container wall of the container (chamber 61) is a gas permeable wall. There are two methods for generating an air flow from the outside of the container to the inside of the container through this air-permeable wall: a case where the inside of the container is generated by suction and a case where the atmosphere outside the container is pressurized to generate an air flow. Each case was tested. In the case of suction, the pressure difference generated by the suction force of the cyclone collecting part was used. In the case of pressurization, the pressure was applied from the outside and the gas was sent into the inside.
Moreover, it tested about the case where an opposing airflow was generated through all the wall surfaces of a chamber, and the case where an opposing airflow was generated through a part of wall surface, respectively.
“Whole wall surface” is the entire container wall in the space where liquid droplets solidify, that is, the entire wall surface of the cylindrical portion in the central portion excluding the inlet, upper end, lower end and outlet of the chamber 61 is made porous. It is.
The “partial wall surface” is porous from the lower end position of the discharge means of the cylindrical portion to the bottom 500 mm. In the case of “partial wall surface”, as shown in FIG. 7, a part of the container wall which is a gas permeable wall is located at a position corresponding to a position directly below the droplet discharge hole of the droplet discharge means.
In both cases, the same cylindrical portion was used, but in the case of “partial wall surface”, a sealing material was stretched outside the portion through which gas did not pass.
Regarding the wall surface material, one of three types of materials, stainless steel, ceramic, and alloy (brass), was used as the wall surface material of the cylindrical portion of the chamber.

[Evaluation method]
<Evaluation of collection rate>
The collection rate (toner recovery rate) was evaluated according to the following evaluation criteria on the amount [g] of collected powder with respect to the solid content [g] of the liquid discharged by discharge for 10 minutes.
◎: 90% or more ○: Less than 90%, 80% or more △: Less than 80%, 70% or more ×: Less than 70%

<Evaluation of particle size distribution>
The average particle size distribution of the collected toner was evaluated according to the following evaluation criteria.
◎: 1.00 or more, less than 1.07 ○: 1.07 or more, less than 1.12 Δ: 1.12 or more, less than 1.15 ×: 1.15 or more

-Particle size measurement method-
A measurement method using a flow particle image analyzer (Flow Particle Image Analyzer) will be described below. The measurement of toner, toner particles and external additives using a flow type particle image analyzer can be performed using, for example, a flow type particle image analyzer FPIA-3000 manufactured by Toa Medical Electronics Co., Ltd.

The measurement is performed according to the following procedure.
-Water used for measurement is passed through a filter to remove fine dust, and water having a measurement range (for example, an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm) in 10 ⁻³ cm ³ of water. Get.
Add a few drops of nonionic surfactant (preferably Contaminone N manufactured by Wako Pure Chemical Industries, Ltd.) to 10 ml of water, add 5 mg of a sample to be measured, and 20 kHz, 50 W using an ultrasonic dispersing device STM UH-50. Dispersion treatment is performed for 1 minute under the condition of / 10 cm ³ .
Next, a dispersion treatment is performed for a total of 5 minutes, and a sample dispersion with a measurement sample particle concentration of 4000 to 8000 pieces / 10 ⁻³ cm ³ (targeting particles in the equivalent circle diameter range) is 0.60 μm. The particle size distribution of particles having an equivalent circle diameter of less than 159.21 μm is measured.

The sample dispersion liquid is passed through a flow path (expanded along the flow direction) of a flat and flat transparent flow cell (thickness: about 200 μm). In order to form an optical path that passes across the thickness of the flow cell, the strobe and the CCD camera are mounted on the flow cell so as to be opposite to each other. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of the particles flowing through the flow cell, so that each particle has a certain range parallel to the flow cell. Photographed as a two-dimensional image. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter.
In about 1 minute, the equivalent circle diameter of 1200 or more particles can be measured, and the number based on the equivalent circle diameter distribution and the ratio (number%) of particles having a prescribed equivalent circle diameter can be measured. The results (frequency% and cumulative%) can be obtained by dividing the range of 0.06-400 μm into 226 channels (divided into 30 channels per octave). In actual measurement, particles are measured in the range where the equivalent circle diameter is 0.60 μm or more and less than 159.21 μm.

Example 1
Using the toner manufacturing apparatus described above, the prepared toner component liquid was discharged, and the toner particles dried and solidified in the chamber were collected by a cyclone collector. The toner was taken out from the toner reservoir 63, and the toner of Example 1 was obtained. The toner particle size distribution (weight average particle diameter / number average particle diameter) was measured with a flow particle image analyzer (Sysmex Corp. FPIA-3000) under the measurement conditions described above. When this was repeated three times, the average of the volume average particle diameter (Dv) was 5.1 μm, the average of the number average particle diameter (Dn) was 4.9 μm, and the average of Dv / Dn was 1.04. .

(Examples 2-6, Comparative Example 1)
Table 1 shows the results of Examples 2 to 6 and Comparative Example 1 evaluated in the same manner as in Example 1 under the above conditions. The same toner liquid and peripheral devices are used.

  From the above results, it was shown that high quality toner can be efficiently produced by using the drying and solidifying method of the present invention.

1: Toner manufacturing apparatus 2: Droplet discharge means 3: Opposing airflow generation means 6: Toner component liquid supply port 7: Toner component liquid flow path 8: Toner component liquid discharge port 9: Elastic plate 10: Liquid column resonance droplet formation Unit 11: Liquid column resonance droplet discharge means 12: Air flow path 13: Raw material container 14: Toner component liquid 15: Liquid circulation pump 16: Liquid supply pipe 17: Liquid common supply path 18: Liquid column resonance flow path 19: Discharge Hole 20: Vibration generating means 21: Liquid droplet 22: Liquid return pipe 23: Merged liquid droplet 24: Nozzle angle 60: Drying collecting means 61: Chamber 62: Toner collecting means 63: Toner reservoir 64: Conveying air flow introduction Port 65: Conveyance airflow discharge port P1: Liquid pressure gauge P2: Chamber pressure gauge

Japanese Patent No. 3786034 Japanese Patent No. 3786035 JP-A-57-201248 JP 2006-293320 A

Claims (10)

  A method for producing particles, comprising: a droplet discharge step for discharging a particle composition liquid from at least one discharge hole to form droplets; and a solidification step for solidifying the droplets. And at least a part of the container wall of the container is made of a gas permeable wall, and in the solidification step, an air flow directed from the outside of the container to the inside of the container is generated through the gas permeable wall. Production method.   The method for producing particles according to claim 1, wherein the air-permeable wall is made of a perforated plate.   The method for producing particles according to claim 2, wherein the perforated plate is made of metal.   The method for producing particles according to claim 1, wherein the air-permeable wall is made of a porous material.   The method for producing particles according to any one of claims 1 to 4, wherein the air flow is generated by setting a negative pressure inside the container.   The method for producing particles according to any one of claims 1 to 4, wherein the air flow is generated by bringing the atmosphere outside the container into a pressurized state.   An apparatus for producing particles, comprising: a droplet discharge unit that discharges a particle composition liquid from at least one discharge hole to form droplets; a solidification unit that solidifies the droplets; and a container that stores the units. In addition, at least a part of the container wall of the container is made of an air permeable wall, and has means for generating an air flow from the outside of the container to the inside of the container through the air permeable wall. .   8. The particle manufacturing apparatus according to claim 7, wherein the air-permeable wall is provided on the entire container wall in a space portion where the liquid droplets are solidified.   8. The particle manufacturing apparatus according to claim 7, wherein the air-permeable wall is provided on a part of a container wall in a space portion where the liquid droplets are solidified.   The particle manufacturing apparatus according to claim 9, wherein a part of the container wall is a container wall at a position corresponding to a position directly below a droplet discharge port of the droplet discharge unit.

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