JP6168385B2 - Particle manufacturing apparatus and particle manufacturing method - Google Patents

Description

  The present invention relates to a particle manufacturing apparatus, a particle manufacturing method, and an electrophotographic toner.

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.

  The toner obtained by the polymerization method is generally easier to obtain with a smaller particle size than the toner obtained by the pulverization method, has a narrow particle size distribution, and has a shape close to a spherical shape. An image in the photographic system has an advantage that it is easy to obtain high image quality. However, on the other hand, the polymerization process requires a long time, and after solidification, it is necessary to separate the solvent and toner particles, and then repeat washing and drying, which requires a lot of time, a large amount of water and energy. There is a drawback.

Therefore, a jet granulation method is known in which a liquid (hereinafter referred to as a toner composition liquid) in which raw material components of toner are dissolved or dispersed in an organic solvent is formed into particles 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.

With respect to such a problem, the toner production method by jet granulation described in Patent Document 4 proposed by the present applicant does not require a large amount of cleaning liquid, repeated separation of solvent and particles, and is extremely efficient in production. Toner with high particle size, energy saving, and narrow particle size distribution.
However, in these methods, when the toner component dissolved or dispersed liquid is ejected from the ejection holes at once through a number of liquid column resonance liquid chambers, the liquid chamber is caused by the vibration of the liquid due to the inertial force inside the liquid supply channel. The internal pressure fluctuates over a long period. If this pressure fluctuation is large, a phenomenon (overshoot) in which the liquid oozes out from the discharge hole occurs, and the discharge cannot be performed. Therefore, there is a problem that a sufficient discharge amount cannot be secured.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a particle production apparatus using a jet granulation method capable of forming stable droplets.

The features of the present invention as means for solving the above-described problems are as follows.
Droplet discharge means for discharging droplets by discharging a particle composition liquid in which the particle component is dissolved or dispersed in a solvent from at least one discharge hole or the particle component is melted ;
A transport airflow forming means for forming an airflow for transporting the droplets discharged from the droplet discharge means;
A liquid having a space in which droplets transported by the transport airflow are introduced and solidified by drying or cooling the droplets by transporting the droplets while contacting the transport airflow to form fine particles. Droplet solidification means;
An apparatus for producing particles having
The droplet discharge means imparts vibration to the liquid in the liquid column resonance liquid chamber in which a plurality of discharge holes are formed by the vibration generation means to form a standing wave by liquid column resonance, and the antinode of the standing wave The liquid is discharged from the discharge holes arranged in the region to become droplets,
The flow path of the particle composition liquid communicating with the droplet discharge means has a structural portion having any structure selected from the following (1) to (3), and the structural compliance of the structural portion is 1.0. A particle production apparatus, wherein the particle production apparatus is × 10 ^{−7 to} 1.0 × 10 ⁻¹⁰ [m ³ / Pa].
(1) A structure in which the whole or a part of the pipe which is the flow path of the particle composition liquid is made of a thin film material with low strength that can be bent.
(2) A structure in which the whole or a part of the pipe, which is the flow path of the particle composition liquid, is configured with an expandable / contractible bellows-shaped bent portion.
(3) Structure in which a part of the piping that is the flow path of the particle composition liquid is made of a compressible material

  According to the particle manufacturing apparatus using the jet granulation method of the present invention, the initial normal discharge rate is high and droplets can be stably formed, so that the productivity of particles can be improved.

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 unit. It is sectional drawing of a discharge outlet. 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 droplet discharge. It is a characteristic view which shows a drive frequency and a droplet discharge speed frequency characteristic. It is the schematic of a particle manufacturing apparatus. It is sectional drawing which shows the structure of a liquid column resonance droplet formation means. It is a figure which shows the path | route for introducing a particle | grain composition liquid into the droplet discharge process in this invention. It is a figure which shows the path | route for introducing a particle | grain composition liquid into the droplet discharge process in this invention. FIG. 13 shows the pressure fluctuation after the droplet discharge in the first embodiment.

  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, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

  An example of the particle production apparatus of the present invention will be described below with reference to FIGS. The particle production apparatus of the present invention includes a droplet discharge means and a droplet solidification 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 one-fluid nozzle, two-fluid nozzle, membrane vibration type discharge means, Rayleigh split type discharge means, liquid vibration type discharge means, and liquid column resonance type discharge means. The means is described in, for example, Japanese Patent Application Laid-Open No. 2008-292976, and the liquid vibration type droplet discharge means is described in 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 particles, for example, liquid droplet resonance can be used. In droplet liquid column resonance, a standing wave due to liquid column resonance is formed by applying vibration to the liquid in the liquid column resonance liquid chamber in which a plurality of ejection holes are formed, and in the region that becomes the antinode of the standing wave. Liquid is discharged from the formed discharge holes.

[Liquid column resonance ejection means]
A preferred example of the droplet discharge means is a liquid column resonance type discharge means that discharges using the resonance of the liquid column. Hereinafter, the liquid column resonance ejection unit 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).

  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. This particle composition liquid is obtained by dissolving or dispersing a component (particulate component) that forms particles to be obtained in a solvent, or is obtained by melting the particulate component. Hereinafter, when the particles are toner, the “particle composition liquid” may be referred to as “toner composition liquid”.

The particle 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 particle 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 particle 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 particle composition liquid 14 in the liquid column resonance liquid chamber 18 is reduced by the discharge of the liquid droplet 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 particle composition liquid 14 supplied from the passage 17 increases. Then, the particle composition liquid 14 is replenished into the liquid column resonance liquid chamber 18. When the particle composition liquid 14 is replenished in the liquid column resonance liquid chamber 18, the flow rate of the particle 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 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 , KNbO _{3, and the} like can be given. 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]. If it is smaller than 1 [μm], the formed droplets may be very small, so that the particles may not be obtained. In the case of a configuration in which solid fine particles such as pigments are contained as the component of the particles, the discharge hole 19 There is a risk that productivity will be reduced due to frequent blockages. In addition, when it is larger than 40 [μm], the diameter of the droplet is large, and when this is dried and solidified to obtain a desired particle diameter of 3 to 6 μm, it is necessary to dilute the particle composition to a very dilute liquid with a solvent. In some cases, a large amount of drying energy is required to obtain a certain amount of particles, which is inconvenient. 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 at a certain angle from the liquid contact surface of the discharge hole 19 toward the discharge port, and the nozzle angle 44 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. When the nozzle angle 44 is 90 °, (c) corresponds, but it is difficult to apply pressure to the outlet, so 90 ° is the maximum value. If the angle is 90 ° or more, no pressure is applied to the outlet of the hole 12, so that the droplet discharge becomes very unstable.
(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 occurring in the liquid column resonance liquid chamber 18 in the liquid column resonance droplet discharge means 11 of FIG. 1 will be described. The sound velocity of the particle composition liquid in the liquid column resonance liquid chamber is c, and vibration is generated. When the driving frequency given from the means 20 to the particle composition liquid as a medium 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. 3A showing the case of a fixed end with N = 1, in the case of velocity distribution, the amplitude of the velocity distribution is zero at the closed end, and the amplitude is 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 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.
When the number exceeds 100, if a desired droplet is to be formed from the 100 ejection holes 19, it is necessary to set a high voltage to the vibration generating means 20, and the behavior of the piezoelectric body as the vibration generating means 20 is increased. Becomes unstable. 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. When the pitch between the discharge holes is smaller than 20 [μm], there is a high probability that the droplets discharged from the adjacent discharge holes collide with each other and become large droplets, leading to deterioration of the particle size distribution of the particles.

  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 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. For this reason, 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 particle 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 particle 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. This example is a resonance mode in which the length L between both ends in the longitudinal direction of the liquid column resonance liquid chamber 18 in FIG. 1 is 1.85 [mm] and N = 2, and the first to fourth discharge holes are provided. FIG. 7 shows a state in which a discharge hole is arranged at the antinode of the N = 2 mode pressure standing wave and a discharge performed with a sine wave with a drive frequency of 340 [kHz] is photographed by the laser shadowgraphy method. As can be seen from the figure, it was possible to discharge droplets with very uniform diameters and almost uniform speeds. 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, the discharge speed from each nozzle is uniform and the maximum discharge speed when the drive frequency is around 340 [kHz] in the first to fourth nozzles. 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.

[Droplet solidification]
The particles (or toner) of the present invention can be obtained by solidifying and then collecting the droplets of the particle composition liquid discharged into the gas from the droplet discharge means described above.

[Droplet solidification means]
The solidification of the liquid droplets can be achieved by drying the liquid droplets in a carrier air stream after jetting the liquid droplets, 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.

[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. 9 is a cross-sectional view of an example of an apparatus for carrying out the method for producing particles of the present invention. The particle manufacturing apparatus 1 mainly includes a droplet discharge means 2 and a dry collection unit 60.
The droplet discharge means 2 is supplied to the droplet discharge means 2 through the liquid supply pipe 16 with the raw material container 13 for storing the particle composition liquid 14 and the particle composition liquid 14 stored in the raw material container 13. A liquid circulation pump 15 that pumps the particle 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 to the liquid droplet discharge means 2 as needed. Can supply. 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, there is a possibility that the particle composition liquid 1 oozes out from the hole 12, and in the case of P1 <P2, there is a possibility that gas enters the discharge means and the discharge may stop. It is desirable that 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.

[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 coalescence by the conveying airflow 101 so that the droplets do not contact each other. Carry the solidified particles to the collection means.

  For example, as shown in FIG. 10, a part of the transport airflow 101 is arranged as a first airflow in the vicinity of the droplet discharge means in the direction perpendicular to the droplet discharge direction, thereby reducing the droplet velocity immediately after the droplet discharge. Can be prevented and coalescence can be prevented. 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. 10, when the anti-adhesion airflow is applied from the lateral direction to the droplet discharge, the trajectory may not overlap when the droplets are conveyed by the anti-adhesion airflow from the discharge port. desirable.

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 in anticipation of a 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 the droplets 21 from adhering to the chamber 61.

[Secondary drying]
When the amount of residual solvent contained in the particles obtained by the dry collection means shown in FIG. 8 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 solvent remains in the particles, not only the particle properties such as heat-resistant storage stability, fixing properties, and charging properties will change over time. Since the solvent evaporates at the time of fixing by heating, the possibility of adversely affecting the user and peripheral equipment is increased. Therefore, sufficient drying is performed.

[Elastic member of liquid feeding part]
In the present invention, the flow passage of the liquid feeding section has a structural portion having a structural compliance of 1.0 × 10 ^{−7 to} 1.0 × 10 ⁻¹⁰ [m ³ / Pa].
In order for the structural portion to have the structural compliance value, it is preferable that the structural portion has a portion made of an elastic member. The elastic part is provided in a part of the liquid supply pipe line, and a part of the wall surface is preferably a thin film and functions as an elastic body. However, the structural compliance is 1.0 × 10 ^{−6 to} 1.0 × 10 ⁻ Any form may be used as long as it is in the range of ¹² [m ³ / Pa].

<Definition of structural compliance>
The compliance represents the degree of compression of the liquid, is defined as the volume displacement per unit pressure, and the unit is [m ³ / Pa].
The structural compliance is a volume displacement amount per unit pressure when a liquid is sealed in a certain container and compressed, and at this time, a structure including a volume change due to deformation of the container is defined as structural compliance.

<Measuring method for structural compliance>
The structural compliance measurement method is described below.
First, a target container or piping is filled with a target liquid using a syringe, and further pressurized.
A pressure sensor (Keyence AP10-S / AP-V80) is arranged in a part of the system, the amount of change of the syringe at a predetermined pressure is read, and the volume is measured.

As a method for increasing the structural compliance, the following methods (1) to (3) can be implemented.
(1) The whole or a part of the flow path is made of a thin film material having low strength, and the structural compliance is increased by utilizing the bending of the thin film.
As the material of the thin film, a metal such as aluminum, SUS, or nickel, a resin film such as PET, or the like can be used, and can be selected in consideration of chemical resistance to the liquid to be used. In the case of an organic material, a metal film is preferable because the resin film may be dissolved.
(2) The whole or a part of the flow path is configured to have a bent portion such as a bellows, and the structure compliance is increased by making it extendable and contractible.
(3) A member having compressibility is provided in a part of the flow path. Examples of the compressible member include an elastic member such as a silicone resin.

Although any of the means for increasing the structural compliance as described above can be used to achieve the object of the present invention, the method (1) is used in the examples of the present invention.
An example of the flow path for increasing the structural compliance by the method (1) is shown in FIGS.
11 shows a structure having a rectangular parallelepiped shape, FIG. 11 (a) is a longitudinal sectional view along the flow path, and FIG. 11 (b) is A in FIG. 11 (a). It is -A sectional drawing.
A rectangular film 70 is provided on a part of the wall surface of the structure portion. As shown in FIG. 11A, in this example, the cross-sectional area of the flow path of the structural portion that increases the structural compliance is made larger than the cross-sectional area of the front and rear flow paths. Such a structure is preferable from the viewpoint of reducing the pressure fluctuation range of the particle composition liquid.
The one used in the example has a flow path depth D of 3 mm in this cross-sectional view. The wall thickness E of the flow path was 2 mm, and the material of the rectangular parallelepiped structure was SUS.

  When the cross-sectional area of the flow path of the structural part that increases the structural compliance is made larger than the cross-sectional area of the front and rear flow paths, the introduction port to the member having the elastic part is provided at the lower part and the discharge port to the discharge member 2 It is preferable for the structure to be disposed at the top so that air does not remain during filling. Further, a structure that does not form an acute angle portion in the space where the liquid exists is also preferable as a structure that does not leave air during filling.

The elastic portion may be of any shape and material that gives the desired structural compliance and is chemically resistant to the liquid. When it is desired to increase the structural compliance, a resinous thin film having a low Young's modulus is preferable. In this case, a chemically resistant member or a member coated with a high material is preferable. For example, PTFE.
It is also possible to use a metal member in order to maintain mechanical strength. Examples of the metal member include SUS404, aluminum, nickel, and the like.

When the thin film was rectangular, the longitudinal direction of the flow channel was 1 to 10 cm, and the short side direction was 0.5 to 1 cm. This shape may be circular, square or any shape.
The thickness of the thin film is in the range of 0.05 to 1 mm, the mechanical strength is maintained, and the structural compliance is in the range of 1.0 × 10 ^{−6 to} 1.0 × 10 ⁻¹² [m ³ / Pa]. It is suitable to keep it.

In the above example, the space having the elastic portion is preferably on the upstream side of the discharge member 2 as described above, but the function can be exhibited even if it is arranged after the discharge step.
The example shown in FIG. 12 is an example in which a structural portion having an elastic portion is installed behind the discharge member.
The structure of this structural portion is the same as that shown in FIG. 11, but the portion corresponding to the introduction port in FIG. 11 communicates with the discharge member, and the portion corresponding to the discharge port is a blind tube. ing.
Further, the space having the elastic portion may be provided anywhere on the downstream side of the element that fluctuates the pressure, such as a pump or a filter, but is more preferably provided in the vicinity of the discharge member.

Next, the toner will be described.
The present invention relates to a method for producing particles, but the particles can also be used as a toner for electrophotography. The description as a toner is described below. Of course, other particles can be produced by appropriately selecting the components.
The toner of the present invention contains at least a resin, and optionally contains a colorant, a wax, a charge adjusting agent, an additive, and other components.

Next, the toner will be described.
The “toner composition liquid” used in the present invention will be described. The toner composition liquid is a liquid in which the toner component is dissolved or dispersed in a solvent.
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. 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 molecular weight of 3,000 to 50,000 from the viewpoint of toner fixing property and offset resistance. As the THF soluble component, a binder resin in which a component having a molecular weight of 100,000 or less is 60 to 100 [%] is also preferable, and the binder resin has at least one peak in a molecular weight region of 5,000 to 20,000. Is more preferable.

Next, the toner will be described.
[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 are used. The magnetic material can also be used as a colorant. As the usage-amount of the said magnetic body, 10-200 parts of magnetic bodies are preferable with respect to 100 parts of binder resin, and 20-150 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 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.
The amount of the master batch used is preferably 0.1 to 20 parts with respect to 100 parts of the 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, and a conventionally known dispersant can be used. Specific examples of commercially available products include “Azisper PB821” and “Azisper PB822”. ”(Manufactured by Ajinomoto Fine Techno Co., Ltd.),“ Disperbyk-2001 ”(manufactured by Big Chemie),“ EFKA-4010 ”(manufactured 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 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 amount of the dispersant added is preferably 1 to 200 parts, more preferably 5 to 80 parts, relative to 100 parts of the colorant. If it is less than 1 part, the dispersibility may be lowered, and if it exceeds 200 parts, 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. 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 Waxes mainly composed of fatty acid esters such as acid ester wax and caster wax. Deoxidized carnauba wax and other fatty acid esters that have been partially or wholly deoxidized are included.

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, more preferably 0.5 to 10 parts with respect to 100 parts 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.

<Solvent>
The solvent is not particularly limited as long as it can dissolve the binder resin and stably disperse the dispersion such as the colorant and the release agent, and can be appropriately selected according to the purpose. A solvent that can be easily dried is preferable because it is used when a toner is produced by droplet formation in the medium. From the viewpoint of drying, the boiling point of the solvent is preferably 100 ° C. or less because the drying speed is fast.
As the solvent, for example, ethers, ketones, esters, hydrocarbons, and alcohols are preferable, and tetrahydrofuran (THF), acetone, methyl ethyl ketone (MEK), ethyl acetate, and toluene are more preferable. These may be used individually by 1 type and may use 2 or more types together.

The solid content concentration of the particle composition liquid of the present invention is not limited as long as droplet formation can be performed normally. However, the solid content concentration of the particle composition liquid is preferably low and is preferably 30% or less. More preferably, it is 5 to 20%.
Since the change from the solvent to the particle composition liquid is started after the droplet discharge is started, it is preferable that the change in physical properties such as the solution viscosity, the sound speed of the liquid, and the surface tension of the liquid is less, because it is not necessary to change the discharge conditions greatly, A lower solid content concentration of the particle composition liquid is preferable. However, if the solid content concentration of the particle composition liquid is too low, the drying energy and the like are increased, and the production efficiency is lowered, which is not preferable.

  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 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].

  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].

Examples of the present invention are shown below, but the scope of the present invention is not limited by these Examples. The “part” shown below represents a part.
First, the formulation of the dissolution or dispersion used in the embodiment is shown.
The injection conditions are as described later.

<Preparation of solution of styrene-n-butyl acrylate copolymer resin>
9 parts of ethyl acetate was mixed with 1 part of styrene-n-butyl acrylate copolymer resin to completely dissolve the resin, thereby preparing a solution of styrene-n-butyl acrylate copolymer resin. The styrene-n-butyl acrylate copolymer resin had a mass average molecular weight of 45,000 and a glass transition temperature of 59 ° C.

<Preparation of colorant dispersion>
Carbon black (Regal 400, manufactured by Cabot) 20 parts and pigment dispersant 2 parts were primarily dispersed in 78 parts 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 dyno mill to prepare a secondary dispersion from which aggregates were completely removed. Further, a dispersion was prepared by passing through a polytetrafluoroethylene filter having 1 μm pores and dispersing to a submicron region.

<Preparation of carnauba wax dispersion>
Carnauba wax (manufactured by Toa Kasei Co., Ltd.) and 4 parts of ethyl acetate were charged, heated to 85 ° C. and stirred for 20 minutes to dissolve the carnauba wax, and then rapidly cooled to precipitate carnauba wax fine particles. This carnauba wax dispersion was further finely dispersed by a strong shearing force using a star mill LMZ06 (manufactured by Ashizawa Finetech Co., Ltd.) filled with zirconia beads having a diameter of 0.1 μm, and the average particle size of carnauba wax was 0.3 μm. The maximum particle size was adjusted to 0.8 μm or less. For measuring the particle size of the carnauba wax, NPA150 manufactured by Microtrac was used.

<Preparation of toner composition liquid>
1000 parts of a solution of styrene-n-butyl acrylate copolymer resin, 25 parts of a colorant dispersion, 50 parts of a carnauba wax dispersion, and 80 parts of ethyl acetate were mixed. This mixed liquid was passed through a filter having an opening of 1 μm to prepare a toner composition liquid having a solid content of 10%.

<Toner production device>
Toner was manufactured using the toner manufacturing apparatus 1 having the configuration shown in FIG.
The size and conditions of each component of the toner manufacturing apparatus 1 are shown below.

(Toner collecting part)
The chamber 61 has an inner diameter of φ400 mm and a height of 2000 mm, and is vertically fixed. The upper end and the lower end are narrowed, the diameter of the carrier airflow inlet is φ50 mm, and the diameter of the carrier airflow outlet is φ50 mm. is there. 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 coalescence prevention air flow was 10.0 m / s and nitrogen at 40 ° C.

(Liquid column resonance droplet discharge means)
As the droplet discharge means, a liquid column resonance droplet discharge means having the structure shown in FIG. 1 was used.
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 one in which one discharge hole is arranged at the position of the antinode of the wave was used. The discharge unit used was an accumulation of 1,280 liquid column resonance chambers.
The sine wave drive signal generation source applied to the mechanical vibration means was a NF company function generator WF 1973, which was connected to the vibration generation means by a polyethylene-coated lead wire. The driving frequency at this time is 330 [kHz] according to the liquid resonance frequency.

<Evaluation method of particle size distribution>
The weight average particle diameter (D4) and number average particle diameter (Dn) of the obtained toner were measured with a particle size measuring device (Multisizer III, manufactured by Beckman Coulter, Inc.) with an aperture diameter of 100 μm, and analyzed software (Beckman Coulter). Analysis was performed using Multisizer 3 Version 3.51). Specifically, 0.5 mL of 10% by weight surfactant (alkylbenzene sulfonate Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a 100 mL glass beaker, and 0.5 g of each toner is added. Stir and then add 80 mL of ion exchange water. The obtained dispersion was subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). The dispersion was measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter) as the measurement solution. In the measurement, the toner sample dispersion was dropped so that the concentration indicated by the apparatus was 8 ± 2%. In this measurement method, it is important that the concentration is 8 ± 2% from the viewpoint of measurement reproducibility of the particle diameter. Within this concentration range, no error occurs in the particle size.
After measuring the volume and number of the toner, the volume distribution and the number distribution were calculated, and the weight average particle diameter (D4) and the number average particle diameter (Dn) of the toner were obtained from the obtained distribution. As an index of the particle size distribution, D4 / Dn obtained by dividing the weight average particle size (D4) of the toner by the number average particle size (Dn) was used. If it is completely monodisperse, it becomes 1, and the larger the value, the wider the distribution.

[Example 1]
(Toner composition liquid)
The toner composition liquid 14 stored in the storage unit 13 was depressurized to −90 kPa while stirring with a stirrer to complete the deaeration process.

(Structural part with elastic body)
As the structure portion having an elastic body, the structure shown in FIG. 11 was used.
In the cross-sectional view shown in FIG. 11B, the flow path depth D is 3 mm. The wall thickness E of the flow path was 2 mm, and the material of the rectangular parallelepiped structure was SUS.
As the elastic portion, an aluminum thin plate having a width of 1 cm, a length of 8 cm, and a thickness of 50 μm was used. At this time, the structural compliance of the elastic portion was 5.4 × 10 ⁻⁸ [m ³ / Pa].

(Droplet ejection-Droplet solidification)
The drive voltage was 10.0 V and the frequency was 330 kHz.
The discharged toner composition liquid was dried and solidified in the chamber, and the toner particles were collected by a cyclone collector. The toner was taken out from the toner storage container, and the toner of Example 1 was obtained.
In order to evaluate the stability of the liquid flow, a pressure sensor (AP10-S / AP-V80 manufactured by Keyence) for measuring the liquid pressure was inserted between the discharge step 2 and the space having the elastic portion.

At the start of discharge, the mechanical vibration means of all 1,280 liquid column resonance flow paths were driven to start discharging liquid droplets simultaneously from all discharge holes, but pressure fluctuations in the flow path overshoot. The discharge could be started stably. The pressure fluctuation at this time is shown in FIG.
The particle size of the toner particles of Example 1 was measured. The weight average particle diameter (D4) was 5.3 μm, the number average particle diameter (Dn) was 4.9 μm, and D4 / Dn was 1.08.

[Example 2]
A toner was prepared in the same manner as in Example 1 except that the thickness of the aluminum thin plate was 100 μm and a space having an elastic portion as shown in FIG. 12 was provided after the discharging step.
When the particle diameter of the obtained toner particles was measured, the weight average particle diameter (D4) was 5.3 μm, the number average particle diameter (Dn) was 5.0 μm, and D4 / Dn was 1.07.

[Examples 3 to 6]
A sonar was produced in the same manner as in Example 1 except that the material shown in Table 1 was used as the material of the elastic portion.
Table 1 shows the weight average particle diameter (D4), number average particle diameter (Dn), and D4 / Dn of the obtained toner.

[Comparative Example 1]
A sonar was produced in the same manner as in Example 1 except that a space having an elastic portion was not provided in the introduction route of the toner composition liquid.
Table 1 shows the weight average particle diameter (D4), number average particle diameter (Dn), and D4 / Dn of the obtained toner.
[Comparative Example 2]
A sonar was produced in the same manner as in Example 1 except that the material shown in Table 1 was used as the material of the elastic portion.
Table 1 shows the weight average particle diameter (D4), number average particle diameter (Dn), and D4 / Dn of the obtained toner.

  Table 1 lists the numerical values of the form, material, and structural compliance of the elastic portion of each example and comparative example. In addition, as a result of the pressure measurement to evaluate the discharge stability, the maximum value of the pressure when overshooting, the ratio of discharging after 10 seconds, and the result of the particle diameter measurement are listed for reference.

As described above, Examples 1 to 6 have a high initial normal discharge rate, and good discharge is obtained.
Further, in Comparative Example 1 in which a space having an elastic portion was not provided, it is presumed that minute droplets were discharged due to an increase in ejection failure, and the fine particles increased due to drying and collection.
In Comparative Examples 1 and 2, since the structural compliance is outside the numerical range defined in the present invention, ejection failure occurs due to overshoot, and the ratio of the number of nozzles that can be ejected after 10 seconds is reduced.

1: toner production apparatus 2: droplet discharge means 6: toner composition liquid supply port 7: toner composition liquid flow path 8: toner composition liquid discharge port 9: elastic plate 10: liquid column resonance droplet discharge unit 11: liquid column resonance Droplet discharge means 12: air flow passage 13: toner composition liquid storage section 14: toner composition 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 Generation means 21: Droplet 24: Nozzle angle 60: Dry collection means 61: Chamber 62: Solidified particle collection means 63: Solidified particle storage section 64: Conveyance airflow inlet 65: Conveyance airflow outlet 70: Film 71: Particles Composition liquid flow path 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 (6)

Droplet discharge means for discharging droplets by discharging a particle composition liquid in which the particle component is dissolved or dispersed in a solvent from at least one discharge hole or the particle component is melted ;
A transport airflow forming means for forming an airflow for transporting the droplets discharged from the droplet discharge means;
A liquid having a space in which droplets transported by the transport airflow are introduced and solidified by drying or cooling the droplets by transporting the droplets while contacting the transport airflow to form fine particles. Droplet solidification means;
An apparatus for producing particles having
The droplet discharge means imparts vibration to the liquid in the liquid column resonance liquid chamber in which a plurality of discharge holes are formed by the vibration generation means to form a standing wave by liquid column resonance, and the antinode of the standing wave The liquid is discharged from the discharge holes arranged in the region to become droplets,
The flow path of the particle composition liquid communicating with the droplet discharge means has a structural portion having any structure selected from the following (1) to (3), and the structural compliance of the structural portion is 1.0. A particle production apparatus, wherein the particle production apparatus is × 10 ^{−7 to} 1.0 × 10 ⁻¹⁰ [m ³ / Pa].
(1) A structure in which the whole or a part of the pipe which is the flow path of the particle composition liquid is made of a thin film material with low strength that can be bent.
(2) A structure in which the whole or a part of the pipe, which is the flow path of the particle composition liquid, is configured with an expandable / contractible bellows-shaped bent portion.
(3) Structure in which a part of the piping that is the flow path of the particle composition liquid is made of a compressible material 2. The particle manufacturing apparatus according to claim 1, wherein a structural compliance of the structural portion is 1.0 × 10 ^{−8 to} 1.0 × 10 ⁻⁹ [m ³ / Pa].   3. The particle according to claim 1, wherein the structural part is a pipe part provided in a part of a pipe of the liquid flow path, and a part of a wall surface of the pipe part is formed of a metal thin film. manufacturing device. 3. The structure according to claim 1, wherein the structural part is a pipe part provided in a part of a pipe which is a flow path of a liquid path, and a part of a wall surface of the pipe part is formed of a resin thin film. The particle manufacturing apparatus as described. A droplet discharge step in which the particle component is dissolved or dispersed in a solvent from at least one discharge hole , or a particle composition liquid formed by melting the particle component is discharged to form droplets;
A transport step of transporting the droplets discharged in the droplet discharge step by a transport air flow;
A droplet solidification step of solidifying the droplets by drying or cooling the droplets conveyed by contacting the droplets conveyed by the conveyance airflow to form fine particles; and
A method for producing particles having
A flow path communicating with a discharge means for performing the droplet ejection step, has a structure portion with any structure selected from the following (1) to (3), the structure compliance of the structural part is 1.0 It is x10 < ^-7 > -1.0 * 10 < ^-10 > [m < ³ > / Pa] , The manufacturing method of the particle | grain characterized by the above-mentioned.
(1) A structure in which the whole or a part of the pipe which is the flow path of the particle composition liquid is made of a thin film material with low strength that can be bent.
(2) A structure in which the whole or a part of the pipe, which is the flow path of the particle composition liquid, is configured with an expandable / contractible bellows-shaped bent portion.
(3) Structure in which a part of the piping that is the flow path of the particle composition liquid is made of a compressible material 6. The method for producing particles according to claim 5 , wherein the particles are electrophotographic toner.