JP2015020144A - Manufacturing method of particle and toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a particle using an injection granulation method, that enables manufacturing of a toner and a particle having narrow particle size distribution, through suppressing particle adhesion on an air flow passage wall face.SOLUTION: A manufacturing method of a particle includes: a droplet discharge process of discharging liquid including a particulate component from a discharge port so as to make a droplet; and a solidification process in the droplet discharge process of solidifying the droplet discharged from the discharge port by conveyance air flow within an air flow passage. In the manufacturing method of a particle, Reynolds number (Re) of the air flow passage is 4000≤Re<10000.

Description

  The present invention relates to a method for producing particles and toner used for developing an electrostatic 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, a jet granulation method is known in which a liquid (hereinafter referred to as a toner composition liquid) in which a raw material component of toner is dissolved or dispersed in an organic solvent is granulated 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 composition liquid is sprayed, the droplets coalesce before the formed droplets are dried, and the solvent is dried in that state to obtain a toner. As a result, the resulting toner The particle size distribution was inevitably widened, and the particle size distribution was not satisfactory.

In order to solve such a problem, the method for producing particles and toner by jet granulation utilizing liquid column resonance described in Patent Document 4 has a very high production efficiency, energy saving, and a narrow particle size distribution. Can be manufactured.
However, the method described in Patent Document 4 has a problem in that particle adhesion to the wall surface of the air flow path occurs and the particle recovery rate decreases. In addition, there is a problem in that undried particles adhere to the air channel wall surface to generate bound particles in which the particles adhere to each other, and collection for a long time deteriorates the particle size distribution of the recovered particles.

  The present invention has been made in view of the above problems, and in the method for producing particles and toner in the jet granulation method, the adhesion of particles on the air channel wall surface is suppressed, and thus the particles and toner having a narrow particle size distribution are suppressed. It aims at providing the manufacturing method which can be manufactured.

The inventor discharges a liquid containing a particleizing component from a discharge hole to form a droplet, and
In a particle manufacturing method comprising a solidification step in which the droplets are solidified by a carrier airflow in an air channel, the inventors found that the problem can be solved by setting the Reynolds number (Re) of the air channel to 4000 ≦ Re <10000. The present invention has been completed.
The present invention relates to a method for producing particles as described in (1) below.

(1) a droplet discharge step of discharging a liquid containing a particulate component from a discharge hole into droplets;
A solidification step of solidifying the liquid droplets discharged from the discharge holes in the liquid droplet discharge step by a carrier airflow in an air flow path,
A method for producing particles, wherein the Reynolds number (Re) of the air flow path is 4000 ≦ Re <10000.

The present invention, which is a means for solving the above problems, has the following specific effects.
According to the method for producing particles and toner of the present invention, it is possible to suppress adhesion of particles on the air channel wall surface and obtain particles and toner having a very narrow particle size distribution which has not been obtained conventionally.

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 a figure which shows the mode of the actual droplet discharge in a liquid column resonance droplet formation means. It is a characteristic view which shows a drive frequency and a droplet discharge speed frequency characteristic. It is a figure showing the example of arrangement | sequence of the discharge hole of a discharge hole surface. FIG. 2 is a schematic diagram illustrating an example of a toner manufacturing apparatus. It is a figure which shows a binding particle.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated based on drawing. 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, and these changes and modifications are included in the scope of the claims of this application. Therefore, the following description is an example of the embodiment of the present invention, and does not limit the scope of claims of this application.

  An example of an apparatus for carrying out the method for producing particles of the present invention will be described below with reference to FIGS. The apparatus for carrying out the method for producing particles and toner according to the present invention is divided into droplet discharge means (liquid column resonance droplet discharge means), droplet solidification means, and solidified particle collecting means. Each is explained below.

[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 droplet discharge means-
A liquid column resonance type droplet discharge means for discharging droplets by utilizing the resonance of the liquid column will be described.
FIG. 1 shows a liquid column resonance droplet discharge means 11. The liquid common supply path 17 and the liquid column resonance liquid chamber 18 are included. 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).

As the liquid discharged from the droplet discharge means in the present invention, a particle component-containing liquid containing a component that forms particles is used, but the particle component-containing liquid may be in a liquid state under the discharge conditions.
As the particle component-containing liquid, a “particle component dissolved / dispersed liquid” in which the component of the particle to be obtained is dissolved or dispersed in a solvent may be used, or the particle component is in a molten state. The “particle component melt” present in the above may be used. In the following, the present invention will be described by taking as an example the case where toner is obtained as particles, but the “particle component-containing liquid” for producing the toner is particularly referred to as “toner composition liquid”.

  The toner composition liquid 14 passes through a liquid supply pipe by a liquid circulation pump (not shown) and flows into the liquid common supply path 17 of the liquid column resonance droplet forming unit 10 shown in FIG. 2, and the liquid column resonance droplet shown in FIG. It is supplied to the liquid column resonance liquid chamber 18 of the discharge means 11. A pressure distribution is formed in the liquid column resonance liquid chamber 18 filled with the toner composition 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 composition 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 composition liquid 14 in the liquid column resonance liquid chamber 18 decreases due to the discharge of the liquid droplets 21, a suction force due to the action of the liquid column resonance standing wave in the liquid column resonance liquid chamber 18 acts, and the liquid common supply The flow rate of the toner composition liquid 14 supplied from the passage 17 increases, and the toner composition liquid 14 is replenished in the liquid column resonance liquid chamber 18. When the toner composition liquid 14 is replenished in the liquid column resonance liquid chamber 18, the flow rate of the toner composition 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 liquid column resonance droplet forming unit 10 in order to dramatically improve productivity. The range is not limited, but one liquid column resonance droplet forming unit provided with 100 to 2000 liquid column resonance liquid chambers 18 can achieve both operability and productivity, and is most preferable. 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. Even in the case where the toner contains a solid fine particle such as a pigment as a constituent component of the toner, the discharge hole 19 is not clogged, and the 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.

  In addition, 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 hole, 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 hole, 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 of 60 to 90 ° is preferable. When the angle is 60 ° or less, it is difficult to apply pressure to the liquid and it is difficult to process the thin film 41, which is not preferable.
(C) corresponds to the case where the nozzle angle 24 is 90 ° in (b). Since it is difficult to apply pressure to the outlet, 90 ° is the maximum value. When the angle exceeds 90 °, no pressure is applied to the outlet of the discharge hole 19 and the droplet discharge becomes very unstable.
(D) is a combination of (a) and (c). In this way, the shape may be changed step by step.

Next, the mechanism of droplet formation by the liquid column resonance droplet forming unit in the 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 composition liquid in the liquid column resonance liquid chamber is c and the driving frequency applied to the toner composition liquid as a medium from the vibration generating means 20 is f, the wavelength λ at which the liquid resonance occurs is represented by the following formula ( 1).
λ = c / f (1)

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 (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 with 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 driving frequency f is derived from the above formula 1 and the above formula (2) as the following formula (3).
f = N × c / (4L) (3)
However, in reality, since the liquid has a viscosity that attenuates resonance, the vibration is not amplified infinitely, and has a Q value. As shown in equations (4) and (5) described later, Resonance also occurs at a frequency in the vicinity of the most efficient drive frequency f shown in (3).

  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. 4A 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 at which the moving speed of the medium (liquid) in the longitudinal direction becomes zero, and conversely, the pressure becomes maximum. 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 from the above equation (2) as 324 kHz. In another 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], and there are wall surfaces at both ends using the same conditions as described above. Thus, when N = 4 resonance mode equivalent to the fixed ends on both sides is used, the most efficient resonance frequency is derived from the above equation (2) 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 whose main component is the drive frequency f in the range determined by the following formulas (4) and (5) using the lengths of both L and Le. It is possible to eject liquid droplets from the ejection holes by inducing liquid column resonance.

N × c / (4L) ≦ f ≦ N × c / (4Le) (4)
N × c / (4L) ≦ f ≦ (N + 1) × c / (4Le) (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. From the viewpoint of improving productivity, a plurality of discharge holes 19 are provided in one liquid column resonance liquid chamber 18, and 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 can be kept low when a desired droplet is formed from the discharge port 19, and the behavior of the piezoelectric body as the vibration generating means 20 can be stabilized. Can do. Moreover, when opening the some discharge port 19, it is preferable that the pitch between discharge ports is 20 [micrometers] or more and below the length of a liquid column resonance liquid chamber. By setting the pitch between the discharge ports to 20 [μm] or more, it is possible to reduce the probability that droplets discharged from adjacent discharge ports collide with each other to form large droplets, and the toner particle size distribution. Can be improved.

  Next, the state of the liquid column resonance phenomenon occurring in the liquid column resonance liquid chamber in the droplet discharge head in the liquid column resonance 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 with each other (height h2 shown in FIG. 1). In comparison, the height of the frame serving as the fixed end (height h1 shown in FIG. 1) is about twice or more. Therefore, FIG. 6 shows temporal changes in velocity distribution and 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, the filling of the toner composition liquid 14 into the liquid column resonance liquid chamber 18 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 composition 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.

  Next, an example of a configuration in which droplets are actually ejected by the liquid column resonance phenomenon will be described. An example of this is a resonance mode in which the length L between both ends in the longitudinal direction of the liquid column resonance liquid chamber 18 is 1.85 [mm] and N = 2 in FIG. The first to fourth discharge holes are arranged at the antinode of the N = 2 mode pressure standing wave, and the discharge performed with a sine wave with a drive frequency of 340 [kHz] is photographed by the laser shadowgraphy method FIG. 7 shows the state. As can be seen from the figure, the discharge of droplets having a uniform diameter and a substantially uniform speed was realized.

  FIG. 8 is a characteristic diagram showing droplet velocity frequency characteristics when driven by the same amplitude sine wave with a drive frequency of 290 [kHz] to 395 [kHz]. As can be seen from the figure, in the first to fourth nozzles, the discharge speed from each nozzle was uniform and the maximum discharge speed when the drive frequency was around 340 [kHz]. From this result, it can be seen that, in the second mode of the liquid column resonance frequency, 340 [kHz], uniform ejection is realized at the antinode position of the liquid column resonance standing wave. Further, from the characteristic results of FIG. 8, the droplet is between the droplet discharge speed peak at 130 [kHz] which is the first mode and the droplet discharge speed peak at 340 [kHz] which is the second mode. It can be seen that the characteristic frequency characteristic of the liquid column resonance standing wave of the liquid column resonance that does not discharge is generated in the liquid column resonance liquid chamber.

The arrangement of the discharge holes 19 will be described below.
FIG. 9 is a diagram illustrating an arrangement example of the discharge holes on the discharge hole surface. 9A is a diagram similar to FIG. 1, FIG. 9B is a diagram showing an example in which the discharge holes are arranged so as to overlap with the transport airflow direction, and FIG. 9C is the transport airflow direction. It is a figure which shows the example arranged so that several discharge hole may not overlap with respect to this.
As shown in FIG. 9 (B), when the discharge holes are arranged so as to overlap in the direction of the conveying air flow, the discharged particle-containing component-containing liquid droplets intersect each other before reaching the region to be dried and solidified. Unity will occur. In the apparatus for carrying out the method for producing particles of the present invention, as shown in FIG. 9C, it is preferable to arrange the discharge holes so that the plurality of discharge holes do not overlap with each other in the direction of the air flow of conveyance.

-Droplet solidification-
Toner can be obtained by solidifying and then collecting the droplets of the toner composition liquid discharged into the gas from the liquid column resonance droplet discharge means described above.

-Droplet solidification means-
In order to solidify the liquid droplets, the concept varies depending on the properties of the toner composition liquid, but basically any means can be used as long as the toner composition liquid can be brought into a solid state.
For example, if the toner composition liquid is obtained by dissolving or dispersing a solid raw material in a volatile solvent, the liquid can be achieved by drying the liquid droplets in a conveying airflow after the liquid 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 particles are not completely dried, they may be additionally dried in a separate step after the 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.

-Means for collecting solidified particles-
The solidified particles can be recovered from the air by a known powder collecting means such as cyclone collecting or a back filter.

FIG. 10 is a cross-sectional view of an example of an apparatus for performing the toner manufacturing method. The toner manufacturing apparatus 1 mainly includes a droplet discharge means 2 and a dry collection unit 60.
The droplet discharge means 2 supplies the raw material container 13 for storing the toner composition liquid 14 and the toner composition liquid 14 stored in the raw material container 13 to the droplet discharge means 2 through the liquid supply pipe 16. Further, a liquid circulation pump 15 for pumping the toner composition liquid 14 in the liquid supply pipe 16 to return to the raw material container 13 through the liquid return pipe 22 is connected, and the toner composition liquid 14 is discharged at any time by a droplet discharge means. 2 can be supplied. 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. The pressure of the liquid delivery to the droplet discharge means 2 and the pressure in the dry collection unit are pressure gauges P1, P2. Managed by. At this time, if the relationship of P1> P2, the toner composition liquid 1 may ooze out from the discharge hole 19, and if P1 <P2, gas may enter the discharge means and the discharge may stop. , P1≈P2.
In the chamber 61, a descending airflow (conveyance airflow) 101 formed 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.

-Airflow-
When the ejected droplets come into contact with each other before drying, the droplets coalesce into one particle (hereinafter this phenomenon is referred to as 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, resulting in coalescence. Since this phenomenon occurs constantly, the particle size distribution is greatly deteriorated when the particles are collected. In order to prevent coalescence, the drop in the velocity of the droplets is eliminated, coalescence is prevented by the coalescence prevention air flow 102 so that the droplets do not contact each other, and the solidified particle collecting means 62 is solidified while the droplets are solidified by the conveying airflow 101. Need to be transported.

-Unification airflow-
As shown in FIG. 1, the coalescence prevention airflow 102 indicates an airflow immediately after droplet discharge, and is preferably perpendicular to the discharge direction. There is no particular limitation on the type of gas constituting the coalescence prevention airflow 102, and air or a nonflammable gas such as nitrogen may be used. Further, the temperature of the coalescence prevention airflow 102 can be adjusted as appropriate, and it is desirable that there is no fluctuation during production. The speed of the coalescence prevention air flow 102 is preferably 7 [m / s] or more, and more preferably 15 [m / s] or more. Thereby, the particle size distribution of the obtained particles can be further reduced.

-Conveyance airflow-
As shown in FIG. 10, the carrier airflow 101 indicates the airflow in the air flow path 61, and carries the particles to the solidified particle collecting means 62. 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. The velocity of the carrier airflow 101 is set to be 1000 times or more of the terminal velocity (v _s ) of the particles. The terminal velocity is represented by the following formula (6), which is a velocity when the resistance force and buoyancy force exerting an upward force on the particle and the downward gravity are balanced, and once the particle reaches that velocity, Thereafter, the speed does not change and becomes constant. When the carrier airflow 101 is at a velocity less than 100 times the terminal velocity, the particles stay in the air channel and easily adhere to the inner wall of the air channel.

v _s : terminal velocity [m / s] or [cm / s]
D _p : particle diameter [m] or [cm]
ρ _p : Particle density [kg / m ³ ] or [g / cm ³ ]
ρ _f : fluid density [kg / m ³ ] or [g / cm ³ ]
g: Gravity acceleration [m / s ² ] or [cm / s ² ]
η: fluid viscosity [Pa · s] or [g / (cm · s)]

-Air flow path-
It is desirable that the air flow path can adjust the temperature of the inner wall as appropriate, and that there is no variation over time or variation due to position during production. Examples of means for adjusting the temperature of the air flow path include a hot water jacket and a rubber heater, but there is no particular limitation as long as the temperature can be adjusted.
In the present invention, the Reynolds number (Re) of the air channel is set to 4000 ≦ Re <10000.
The temperature of the air flow path wall surface is preferably 30 ° C. or higher, more preferably 100 ° C. or higher, with respect to the carrier airflow 101.

  Depending on the Reynolds number, different flow regions can be characterized, such as laminar and turbulent flow in the air channel. Generally, if Re <2100, laminar flow, and if Re ≧ 4000, turbulent flow. In the range of 2100 ≦ Re <4000, it is unstable and is called a transition region. In a turbulent flow field of 4000 ≦ Re <10000, when a temperature gradient is formed between the air channel wall surface and the carrier airflow, the particles move from the high temperature part toward the low temperature part. By making the air channel inner wall surface temperature higher than the carrier air flow temperature, it is possible to prevent the particles from adhering to the air channel inner wall and to increase the particle recovery rate. When the turbulent flow field is Re> 10000, the effect of forming a temperature gradient for preventing adhesion is small.

  Moreover, by suppressing particle adhesion, it is possible to suppress the bound particle ratio of the recovered particles and improve Dv / Dn. As shown in FIG. 11, the binder particles are grape-like particles in which the particles are firmly bonded to each other. The binder particles are generated by adhering and depositing undried particles on the wall surface of the air channel. When the particles are collected for a long time, they are separated from the air channel and collected by the solidified particle collecting means 62.

The Reynolds number is represented by the following formula (7).
v: Relative average velocity with respect to the flow of the object (carrier air flow rate [m ³ / s] / air channel cross-sectional area [m ² ]) [m / s]
L: Representative linear dimension (diameter in the case of a cylinder) [m]
μ: Fluid viscosity [Pa · s]
ρ: Fluid density [kg / m ³ ]

As shown in the above equation (7), the Reynolds number is the average velocity relative to the droplet flow, that is, the velocity of the carrier airflow 101, the representative linear dimension of the air flow channel 61 (inner diameter in the case of a cylindrical shape), and the liquid It depends on the viscosity and density of the fluid carrying the drops.
Therefore, the Reynolds number can be controlled by the carrier air velocity, the linear dimension of the air channel, and the fluid type.

The air flow velocity of the carrier can be adjusted as appropriate by installing a suction blower or the like that can be controlled by an inverter after the collecting means 62. Alternatively, adjustment can be made by installing a push-in blower or the like capable of inverter control upstream of the droplet discharge means 2. As a conveyance airflow speed, 1.0 m / s or less is preferable. When the speed is higher than 1.0 m / s, the residence time for drying the droplets in the air channel 61 is not secured, and the particles may be collected by the collecting means 62 without being solidified.
The linear dimension of the air channel is preferably 1.0 m or less. If the volume is made larger than 1.0 m and the volume is increased, the heat loss from the air flow path wall surface increases, so that the energy loss of the dry collection unit increases.

-Secondary drying-
When the amount of residual solvent contained in the toner particles obtained by the dry collection unit shown in FIG. 10 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.

The toner produced by the method for producing particles of the present invention will be described below.
The toner produced by the method for producing particles of 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 composition liquid” used in the present invention will be described. The toner composition liquid is in a liquid state in which the toner component is dissolved or dispersed in a solvent, or may be free of a solvent as long as it is liquid under the conditions for 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 above toner composition liquid can be prepared, 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. For example, vinyl polymers such as styrene monomers, acrylic monomers, methacrylic monomers, copolymers of these monomers or two or more types, polyester polymers, polyol resins, phenol resins , 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. For example, (1) iron oxide containing magnetic iron oxide such as magnetite, maghemite and ferrite, and other metal oxides, (2) metals such as iron, cobalt, nickel, or these metals and aluminum, cobalt, copper And alloys of metals such as lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, (3), and mixtures thereof. 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-
There is no restriction | limiting in particular as a coloring agent, Resin normally used can be selected suitably and can be 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 according to 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. From the viewpoint of pigment dispersibility, it is preferable that the compatibility with the binder resin is high, and conventionally known ones 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 Big Chemie), “EFKA-4010” (manufactured by EFKA), and the like. It is done.

  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 less than 0.1 [% by mass], the pigment dispersibility may be insufficient, and when more than 10 [% by mass], the chargeability under high humidity may be deteriorated.

  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. If it is less than 1 part by mass, the dispersibility may be lowered, and if it exceeds 200 parts by mass, the chargeability may be lowered.

-Wax-
The toner composition liquid 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. For example, oxides of 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 blocks thereof Copolymers, plant waxes such as candelilla wax, carnauba wax, wax wax, jojoba wax, animal waxes such as beeswax, lanolin, spermaceti, mineral waxes such as ozokerite, ceresin, petrolatum, montanate ester wax, Examples thereof include waxes mainly composed of fatty acid esters such as 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. If it is less than 70 [° C.], the blocking resistance may be lowered, and if it exceeds 140 [° C.], the offset resistance effect may be difficult to be exhibited.

  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.

-Additives-
In the toner according to the present invention, as other additives, protection of the electrostatic latent image carrier / carrier, improvement of cleaning properties, adjustment of thermal characteristics / electrical characteristics / physical characteristics, resistance adjustment, softening point adjustment, fixing rate For the purpose of improvement, various metal soaps, fluorosurfactants, dioctyl phthalate, tin oxide, zinc oxide, carbon black, antimony oxide, etc. as conductivity imparting agents, and inorganic such as titanium oxide, aluminum oxide, alumina A fine powder or the like can be added as necessary. 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, methacrylic acid ester and acrylic acid ester copolymer, polycondensation system such as silicone, benzoguanamine and nylon, thermosetting resin And polymer particles.

  Such external additives (additives) 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].

  Examples of the cleaning property improver for removing the developer after transfer remaining on the electrostatic latent image carrier or the primary transfer medium include fatty acid metal salts such as zinc stearate, calcium stearate, stearic acid, and polymethyl methacrylate. There may be mentioned polymer fine particles produced by soap-free emulsion polymerization such as fine particles and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 [μm].

<Toner particle size and particle size distribution>
As the particle diameter of the toner, the smaller the toner particle diameter, the better the reproducibility of dots and fine lines, and a sharp and high-quality image can be obtained without roughness. However, if the toner particle size is too small, the apparent adhesive force increases and the developability and transferability are deteriorated. Therefore, the volume average particle size (Dv) is preferably 3 μm to 10 μm, more preferably 3.0 μm to 8.0 μm. It is preferably 4.0 μm to 6.0 μm.
The particle size distribution of the toner of the present invention is represented by the ratio Dv / Dn of the volume average particle size (Dv) to the number average particle size (Dn). If Dv / Dn = 1, the toner has a uniform particle size. It represents a monodispersed toner.

  Electrophotographic development methods are roughly classified into a one-component development method and a two-component development method. In any of the development methods, there is a particle size that is easy to develop, and as a result of repeated development, the particle size and particle size distribution of the toner remaining in the developing device may change, resulting in a change in image quality. Therefore, it is preferable that the particle size distribution is as narrow as possible. However, in the conventional toner production method, it is difficult to make the particle size distribution extremely narrow. For example, in the case of the conventional pulverized toner, the particle size distribution (Dv / Dn) is the productivity of classification. Considering the decrease, it is usually about 1.2 to 1.4.

On the other hand, the toner of the present invention has a very narrow particle size distribution, and the particle size distribution (Dv / Dn) is 1.00 to 1.10 from the viewpoint of obtaining a very stable image even after repeated development. Preferably, 1.00 to 1.05 is more preferable.
The weight average particle diameter (Dv) and the number average particle diameter (Dn) are, for example, a particle size measuring device (Multisizer III, manufactured by Beckman Coulter, Inc.) and analysis software (Beckman Coulter Mutlisizer 3 Version 3.51). Can be analyzed.

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 toner composition liquid of dissolution or dispersion is shown.
-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 is 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 secondary dispersion in which aggregates of 5 μm or more are completely removed. A liquid 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 composition liquid having the following composition to which a resin as a binder resin, the colorant dispersion liquid, and the wax dispersion liquid were added was prepared.
100 parts by mass of a polyester resin as a binder resin, 30 parts by mass of the colorant dispersion, 30 parts by mass of the wax dispersion, and 840 parts by mass of ethyl acetate are stirred for 10 minutes using a mixer having stirring blades, and uniform. Dispersed. Pigments and wax particles did not aggregate due to shock due to solvent dilution.

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 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. The most frequent diameter of the collected toner was set to 5.2 μm.

-Toner production equipment-
The air channel 61 is a cylinder having a height of 2000 mm and is fixed vertically, and a cyclone is installed as the solidified particle collecting means 62. Nitrogen was used as the carrier airflow, and a turbofan (manufactured by Showa Denki Co., Ltd.) capable of inverter control was installed at the cyclone outlet so that the carrier airflow speed in the air flow path 61 could be adjusted. A flat air nozzle (manufactured by MISUMI Corporation) is installed near the coalescence prevention airflow inlet 64 so that the coalescence prevention airflow 102 becomes 10.0 m / s in any experiment, and assist air is supplied when the coalescence prevention air is insufficient. The mechanism was able to flow appropriately. In addition, a silicon rubber heater (manufactured by OHM Heater Co., Ltd.) was installed on the outer wall surface of the air flow path 61 so that the temperature of the inner wall could be adjusted as appropriate.

  The toner production apparatus 1 having the configuration shown in FIG. 10 is used to discharge and collect the toner composition liquid. Table 2 shows the experimental conditions and the Dv / Dn, binder particle ratio, and cyclone particle recovery ratio of the obtained toner. 3 is summarized. Table 1 shows the evaluation criteria for Dv / Dn, binder particle ratio, and particle recovery rate in each experiment.

-Particle size measurement method-
A measurement method using a flow particle image analyzer (Flow Particle Image Analyzer) will be described below. Measurement of the toner, toner particles, and external additives using a flow particle image analyzer can be performed using, for example, a flow particle image analyzer FPIA-3000 manufactured by Sysmex Corporation.
The measurement is performed as follows. First, fine dust is removed through a filter so that the number of particles in 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 water is 20 or less. A few drops of a nonionic surfactant (preferably Contaminone N manufactured by Wako Pure Chemical Industries, Ltd.) is added to 10 ml of this water, 5 mg of a measurement sample is further added, and 20 kHz, 50 W / W with an ultrasonic dispersing device STM UH-50. The dispersion treatment is performed for 1 minute under the condition of 10 cm ³ , and the dispersion treatment is further performed for a total of 5 minutes. Using the sample dispersion having a particle concentration of 4000 to 8000/10 ⁻³ cm ³ (for particles in the equivalent diameter range of the measurement circle) of the measurement sample thus obtained, 0.60 μm or more and less than 159.21 μm The particle size distribution of the particles having the equivalent circle diameter 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 to 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 above-described toner manufacturing apparatus, the produced toner composition liquid was discharged, and the toner particles dried and solidified in the air channel were collected by a cyclone collector. The toner was taken out from the toner storage container, and the toner of Example 1 was obtained. Conditions relating to the carrier air flow rate, the carrier air flow velocity, the air channel diameter, the carrier air flow temperature, and the air channel wall surface temperature are as shown in Table 2, and the Reynolds number and the terminal velocity are calculated based on the equations (6) and (7). did. Table 3 shows the numerical values used for the calculation.
The particle size distribution of the produced toner was measured with a flow type particle image analyzer (Sysmex Corp. FPIA-3000) under the measurement conditions described above. Table 4 shows Dv / Dn, particle binding rate, and particle recovery rate relative to the discharge amount of the toner composition liquid.

(Example 2)
A toner was produced by the same toner composition liquid and toner production method as in Example 1 except that the air channel diameter was 0.30 m. The production conditions and the particle size distribution of the obtained toner are summarized in Tables 2 and 4.

Example 3
A toner was manufactured by the same toner composition liquid and toner manufacturing method as in Example 1 except that the air channel diameter was 0.30 m and the air channel wall surface temperature was 80 ° C. The production conditions and the particle size distribution of the obtained toner are summarized in Tables 2 and 4.

Example 4
A toner was produced by the same toner composition liquid and toner production method as in Example 1 except that the air channel wall surface temperature was 60 ° C. The production conditions and the particle size distribution of the obtained toner are summarized in Tables 2 and 4.

(Example 5)
A toner was manufactured by the same toner composition liquid and toner manufacturing method as in Example 1 except that the conveying air velocity was 1.30 m / s. The production conditions and the particle size distribution of the obtained toner are summarized in Tables 2 and 4.

Example 6
A toner was produced by the same toner composition liquid and toner production method as in Example 1 except that the conveying air velocity was 1.10 m / s. The production conditions and the particle size distribution of the obtained toner are summarized in Tables 2 and 4.

(Comparative Example 1)
A toner was manufactured by the same toner composition liquid and toner manufacturing method as in Example 1 except that the air channel diameter was 0.70 m and the air channel wall surface temperature was 30 ° C. The production conditions and the particle size distribution of the obtained toner are summarized in Tables 2 and 4.

(Comparative Example 2)
Toner was produced by the same toner composition liquid and toner production method as in Comparative Example 1 except that the carrier air flow rate was 1.35 m ³ / min and the air flow path diameter was 0.1 m. The production conditions and the particle size distribution of the obtained toner are summarized in Tables 2 and 4.

(Comparative Example 3)
A toner was produced by the same toner composition liquid and toner production method as in Example 1 except that the air channel diameter was 0.70 m. The production conditions and the particle size distribution of the obtained toner are summarized in Tables 2 and 4.

1: toner production apparatus 2: droplet discharge means 6: toner composition liquid supply 7: toner composition liquid flow path 8: toner composition liquid discharge port 9: elastic plate 10: liquid column resonance droplet forming unit 11: liquid column resonance liquid Drop discharge means 12: Air flow passage 13: Raw material container 14: Toner composition liquid 15: Liquid circulation pump 16: Liquid supply pipe 17: Liquid common supply path 18: Liquid column resonance liquid chamber 19: Discharge hole 20: Vibration generating means 21 : Liquid droplet 22: Liquid return pipe 24: Nozzle angle 41: Thin film 60: Drying collection unit 61: Air flow path 62: Solidified particle collecting means 63: Solidified particle reservoir 64: Unification airflow inlet 65: Conveyance airflow Discharge 101: Conveyance air flow P1: Liquid pressure gauge P2: Pressure gauge in the air flow path

Japanese Patent No. 3786034 Japanese Patent No. 3786035 JP-A-57-201248 JP, 2011-212668, A

Claims (8)

A droplet discharge step of discharging a liquid containing a particulate component from the discharge hole into droplets;
A solidification step of solidifying the liquid droplets discharged from the discharge holes in the liquid droplet discharge step by a carrier airflow in an air flow path,
A method for producing particles, wherein the Reynolds number (Re) of the air flow path is 4000 ≦ Re <10000.   The method for producing particles according to claim 1, wherein a wall surface temperature of the air flow path is set higher than a temperature of the conveying airflow.   The method for producing particles according to claim 2, wherein a wall surface temperature of the air flow path is set to be 100 ° C. or more higher than a temperature of the carrier airflow.   The method for producing particles according to any one of claims 1 to 3, wherein the velocity of the carrier airflow in the air flow path is 100 times or more the terminal velocity of the particles.   The method for producing particles according to claim 1, wherein the liquid containing the particulate component is a toner composition liquid containing a resin, and the particles are toner particles.   The method for producing particles according to claim 5, wherein the toner particles have a volume average particle diameter Dv of 3 [μm] to 10 [μm].   The particle size distribution Dv / Dn, which is the ratio of the volume average particle diameter Dv and the number average particle diameter Dn of the toner particles, is 1.00 to 1.10. Production method.   8. The method for producing particles according to claim 7, wherein a particle size distribution Dv / Dn which is a ratio of a volume average particle size Dv to a number average particle size Dn of the toner particles is 1.00 to 1.05. .