JP6536977B2 - Particle production method - Google Patents

Description

The present invention relates to particle production method such as toner production method using a droplet discharge how to droplets of ejecting liquid from the ejection hole.

  As a method of manufacturing toner for electrostatic charge image development used in image forming apparatuses such as copiers, printers, facsimiles and composite machines thereof based on the electrophotographic recording method, the pulverization method has conventionally been mainstream. In recent years, the polymerization method has been increasingly adopted. The polymerization method is a method of forming toner particles in an aqueous medium, and is referred to as such because it involves the polymerization reaction of toner raw materials at the time of or during the formation of toner particles. As the polymerization method, various polymerization methods are put to practical use, and those utilizing suspension polymerization, emulsion aggregation, polymer suspension (polymer aggregation), ester elongation reaction and the like are known. The toner produced by the polymerization method is called a polymerization toner or a chemical toner.

  Generally, the toner obtained by the polymerization method is characterized in that the particle diameter is easy to obtain, the particle diameter distribution is narrow, and the shape is nearly spherical compared to the toner obtained by the pulverization method. These features bring about the effect that it is easy to obtain high image quality as an image formed by the electrophotographic method. However, it takes a long time for the polymerization process, and after the completion of solidification, it is necessary to separate the solvent and the toner particles, and then to repeat washing and drying, requiring a large amount of water and a large amount of energy. There is a problem such as

  In addition, a liquid (toner component liquid) in which raw material components of toner are dissolved or dispersed in an organic solvent is discharged into fine droplets using a sprayer (atomizer) or the like, and dried to obtain fine particle toner. There is known a toner production method called an injection granulation method to obtain (Patent Documents 1 to 3). According to this toner manufacturing method, since it is not necessary to use water, the time and energy required for washing and drying can be greatly reduced, and the problems of the polymerization method can be avoided.

  When fine particles such as toner are manufactured by a jet granulation method, a liquid containing fine particles containing toner component liquid etc. from a plurality of discharge holes opened at the discharge surface of the droplet discharge device The discharge operation of discharging the liquid droplets is continued, and fine particles are manufactured by solidifying the discharged liquid droplets.

  However, in the case of producing fine particles by discharging droplets of liquid containing fine particles from a plurality of discharge holes opened on the discharge surface of the droplet discharge device, the droplets discharged from each discharge hole are aimed in the discharge direction. If the discharge speed is not properly discharged, the following problems occur. For example, a phenomenon called coalescence may occur in which the discharged droplets come into contact with and integrate with other droplets before they solidify. When such coalescence occurs, the particle diameter of the coalesced fine particles becomes larger than the desired particle diameter. In addition, for example, when a droplet after ejection is vigorously collided with another droplet before it solidifies, the droplet may be broken to break into smaller droplets. In this case, the particle size of the fine particles obtained by solidifying the split microdroplet is smaller than the desired particle size. The occurrence of these events causes a problem that the particle size distribution of the manufactured microparticles is broadened.

  In the particle manufacturing apparatus of Patent Document 4, vibration generating means for applying vibration to the liquid in the liquid chamber is provided, and vibration is applied to the liquid in the liquid chamber to form a standing wave by liquid column resonance in the liquid chamber. The fine particles are manufactured by discharging the liquid downward from the discharge holes formed in the area that becomes the antinode of the standing wave, and then solidifying the droplets formed into droplets. Then, by forming an air flow that flows in the discharge direction of the droplets, the droplets discharged from the discharge holes are transported not only by their own weight but also by the air flow. As a result, the discharge speed of the droplets is increased, and it is possible to suppress the deceleration by the air resistance. As a result, it is possible to reduce contact or violent collision of the discharged droplet with other droplets before it solidifies.

  However, in the droplet discharge device of Patent Document 4, a high frequency power source is connected to the vibration generating means in order to vibrate the vibration generating means at a high frequency of 100 [kHz] or more. Since the piezoelectric material of the piezoelectric element used for the vibration generating means has a dielectric loss, self-heating occurs when the vibration frequency is high. Even in the wiring electrically connecting the vibration generating means and the high frequency power source, the resistance of the wiring generates heat in the wiring. Part of the original power supplied to the piezoelectric element is consumed by these heat generation. As a result, the substantial voltage or current supplied to the input side of the vibration generating means is lower than the target voltage or current, and the discharge capability is reduced. As a result, the frequency per unit time decreases and the discharge amount of particles decreases, and the vibration width of the vibration generating means decreases and the particle diameter reaches the target value, compared to when the target voltage or current is supplied. It was getting smaller.

  This problem is not limited to the case where the droplet discharge means for discharging droplets forms a standing wave by liquid column resonance in the liquid chamber and discharges the liquid by the vibration of the antinode of the standing wave. is there. Further, the above problem is not limited to the case where the liquid discharged from the discharge hole is a fine particle-containing liquid such as a toner component liquid, and is a problem which may similarly occur in, for example, a recording liquid for forming an image in an image forming apparatus.

The present invention has been made in view of the above problems, and an object thereof is to stabilize a discharge capability by suppressing a substantial decrease in voltage or current while vibrating the vibration generating means at a high frequency. It is an object of the present invention to provide a particle production method that can

In order to achieve the above object, the invention of claim 1 solidifies the droplets of the particle component-containing liquid discharged from the discharge hole after discharging the particle component-containing liquid containing the component of particles from the discharge hole. A method for producing particles to be dried, comprising applying vibration to a liquid in a liquid chamber in which discharge holes are formed through a vibration plate by a vibration generating means, and discharging the liquid from the discharge holes to form droplets According to the droplet discharge method , in the droplet discharge method, voltage or current is supplied to the input side of the vibration generating means, and a measurement value of the voltage or current on the output side of the vibration generating means is measured.
The voltage supplied to the input side of the vibration generating means so that the measured voltage measured value or current measured value on the output side of the vibration generating means becomes smaller from the target voltage value or the target current value. Alternatively, by controlling the current , a transport air stream is formed so that the trajectories of the droplets being transported do not overlap in the lateral direction with respect to the droplet ejection direction from the ejection holes, and the particles ejected from the ejection holes The method is characterized in that the droplets of the component-containing liquid are solidified and dried .

  According to the present invention, it is possible to obtain the unique effect of being able to stabilize the discharge capability by suppressing a substantial decrease in voltage or current while vibrating the vibration generating means at a high frequency.

It is the schematic diagram which expanded and showed a part of droplet discharge part of the droplet discharge apparatus of the liquid column resonance type used in embodiment. It is sectional drawing which showed typically a part of liquid column resonance droplet formation unit which is the same droplet discharge apparatus. (A)-(d) is sectional drawing which illustrated the various cross-sectional shape employable as a cross-sectional shape of the discharge hole of the liquid column resonance droplet formation unit. (A) to (d) show the state of the standing wave of the velocity distribution and pressure distribution generated in the liquid in the liquid column resonance liquid chamber of the same liquid column resonance droplet forming unit in the case of N = 1, 2, 3 It is an explanatory view for explaining. (A)-(c) is explanatory drawing for demonstrating the mode of the standing wave of the velocity distribution and pressure distribution which arise in the liquid in the liquid column resonance liquid chamber in the case of N = 4 and 5. FIG. (A)-(d) is explanatory drawing which represented typically the mode of the liquid column resonance phenomenon which arises in the same liquid column resonance liquid chamber. It is a figure which shows a mode that discharge | emission was image | photographed by the laser shadowography method. FIG. 6 is a characteristic diagram showing characteristics of a drive frequency and a droplet discharge speed. It is a block diagram showing an example of composition of piezoelectric element drive circuit 100 of a droplet discharge device concerning this embodiment. It is a block diagram which shows another example of a structure of the piezoelectric element drive circuit 100 of the droplet discharge apparatus which concerns on this embodiment. It is a block diagram which shows another example of a structure of the piezoelectric element drive circuit 100 of the droplet discharge apparatus which concerns on this embodiment. It is a block diagram explaining schematic structure of a current control means. It is a schematic diagram which shows an example of the toner manufacturing apparatus which concerns on this embodiment.

Hereinafter, an embodiment in which the apparatus for producing particles according to the present invention is applied to the production of toner will be described with reference to the drawings.
In the toner manufacturing apparatus of this embodiment, the toner component liquid (liquid containing fine particle component), which becomes toner particles (fine particles) when liquid droplets are solidified, is replenished to the liquid droplet discharge device while the toner component is discharged from the discharge hole of the liquid droplet discharge device. The discharge operation for discharging liquid droplets is continued. Thereafter, the discharged droplets are solidified to obtain toner particles.

  Although it is preferable that the droplet discharge device of the present embodiment has a narrow particle diameter distribution of the droplets to be discharged, there is no particular limitation, and a known device can be used. Examples of the droplet discharge device include a one-fluid nozzle, a two-fluid nozzle, a film vibration type discharge device, a Rayleigh split type discharge device, a liquid vibration type discharge device, a liquid column resonance type discharge device, and the like. For example, a membrane vibration type discharge means is disclosed in Japanese Patent Application Laid-Open No. 2008-292976. Further, as a Rayleigh split type discharge means, there is one disclosed in Japanese Patent No. 4647506. Moreover, as a liquid vibration type discharge means, there are some which were disclosed by Unexamined-Japanese-Patent No. 2010-102195.

  In order to secure the productivity of the toner, the particle size distribution of the droplets is narrow, vibration is applied to the liquid in the liquid column resonance liquid chamber in which a plurality of discharge holes are formed, and a standing wave is formed by the liquid column resonance. Do. A liquid column resonance type droplet discharge device which discharges a liquid from the discharge hole formed in the region which becomes the antinode of the standing wave is preferable. In this embodiment, an example of manufacturing toner using a liquid column resonance type droplet discharge device will be described.

FIG. 1 is a schematic view showing an enlarged part of the droplet discharge portion 11 of the liquid column resonance type droplet discharge device used in the present embodiment.
The droplet discharge portion 11 of the present embodiment is provided with a liquid column resonance liquid chamber 18, and this liquid column resonance liquid chamber 18 is a side wall portion (opening of one of the side wall portions in the longitudinal direction (left and right direction in the drawing) It communicates with the common liquid supply path 17 via a communication path provided in the side wall portion). Further, the liquid column resonance liquid chamber 18 has a plurality of discharge holes 19 for discharging the droplets 21 to one of the wall portions (bottom wall portion in the lower side in the drawing) connecting the side wall portions at both ends in the longitudinal direction. Is equipped. Further, on the upper wall side facing the discharge hole 19 in the liquid column resonance liquid chamber 18, a vibration generating means 20 for generating high frequency vibration to form a liquid column resonance standing wave through the diaphragm 22 is provided. It is provided. The vibration generating means 20 is connected to a high frequency power supply (not shown).

FIG. 2 is a cross-sectional view schematically showing a part of the liquid column resonance droplet forming unit 10 which is the droplet discharge device of the present embodiment. FIG. 2 is viewed from above or below in FIG.
In the present embodiment, the liquid discharged from the droplet discharge unit 11 is a fine particle component-containing liquid in a state in which the component of the fine particles to be manufactured is dissolved or dispersed. Since this embodiment is an example of producing a toner, the liquid containing the fine particle component is described as a toner component liquid. The toner component liquid 14 flows through the liquid supply pipe by a liquid circulation pump (not shown), flows into the common liquid supply path 17 of the liquid column resonance liquid droplet forming unit 10, and the liquid column resonance liquid chamber of each liquid droplet discharge portion 11 Replenished to 18

  A pressure distribution is formed in the toner component liquid 14 filled in the liquid column resonance liquid chamber 18 by the liquid column resonance standing wave generated by the vibration generating means 20. Then, the droplet 21 is discharged from the discharge hole 19 disposed in the region (the region where the amplitude is large and the pressure fluctuation is large) which is the antinode of the liquid column resonance standing wave. The area | region which becomes the antinode of the standing wave by liquid column resonance means the area | regions other than the node of a standing wave. Preferably, the pressure fluctuation of the standing wave is an area having an amplitude large enough to eject the liquid, and more preferably, from the position where the amplitude of the standing wave is maximum to the position where the amplitude is minimum. It is in the range of 1⁄4 wavelength. If it is a region that becomes an antinode of a standing wave, even if a plurality of discharge holes 19 are formed in one liquid column resonance liquid chamber 18 as in the present embodiment, substantially uniform sizes are obtained from each of them. Can be ejected. When the amount of liquid in the liquid column resonance liquid chamber 18 decreases due to the discharge of the droplets 21, the suction force by the action of the liquid column resonance standing wave in the liquid column resonance liquid chamber 18 acts and the common liquid supply path 17 The flow rate of the supplied liquid is increased, and the liquid in the liquid column resonance liquid chamber 18 is replenished.

  The liquid column resonance liquid chamber 18 of the droplet discharge portion 11 has a frame formed of a material such as metal, ceramic, or silicon having a rigidity high enough not to affect the liquid resonance frequency at the driving frequency. It is formed. Further, as shown in FIG. 1, the length L between the side wall portions 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, as shown in FIG. 2, the length (width) W between the side walls at both ends in the short direction of the liquid column resonance liquid chamber 18 is such that the liquid column resonance liquid chamber does not give an extra frequency to the liquid column resonance. It is desirable to be smaller than one half of the length L of eighteen.

  Since it is preferable that a plurality of liquid column resonance liquid chambers 18 be disposed for one liquid column resonance droplet forming unit 10 in order to improve productivity, one liquid column resonance liquid droplet is used in this embodiment. A configuration in which a plurality of liquid column resonance liquid chambers 18 are disposed with respect to the forming unit 10 is employed. The number of liquid column resonance liquid chambers 18 provided for one liquid column resonance droplet forming unit 10 is not particularly limited, but one liquid column resonance provided with 100 to 2000 liquid column resonance liquid chambers 18 The droplet forming unit 10 is preferable because coexistence of operability and productivity can be realized. In the present embodiment, a plurality of liquid column resonance liquid chambers 18 communicate with one liquid common supply path 17.

Further, the vibration generating means 20 in the droplet discharge portion 11 is not particularly limited as long as it can be driven at a predetermined frequency, but as in the present embodiment, the structure in which the diaphragm 22 is attached to the piezoelectric element preferable. The vibrating plate 22 is provided to isolate the piezoelectric element from the liquid column resonance liquid chamber 18 so that the piezoelectric element does not contact with the liquid. The piezoelectric body of the piezoelectric element is, for example, a piezoelectric ceramic such as lead zirconate titanate (PZT), but in general, it is often used in lamination because the displacement amount is small. Other than these, piezoelectric polymers such as polyvinylidene fluoride (PVDF), quartz, single crystals such as LiNbO ₃ , LiTaO ₃ , KNbO _{3 and the} like can be mentioned. Furthermore, it is desirable that the vibration generating means 20 be disposed so as to be individually controllable for each liquid column resonance liquid chamber 18. For example, a configuration is preferable in which one piezoelectric material is divided into a plurality of piezoelectric bodies in accordance with the arrangement of liquid column resonance liquid chambers, and each liquid column resonance liquid chamber can be individually controlled by each piezoelectric body.

The outlet side diameter of the discharge hole 19 is preferably in the range of 1 μm to 40 μm.
If it is smaller than 1 [μm], the formed droplets may be so small that toner may not be obtained. In particular, in the case where solid fine particles such as a pigment are contained as a component of the toner, the solid fine particles may block the discharge hole 19 and may reduce the productivity of the toner. On the other hand, if the particle diameter is larger than 40 μm, the diameter of the droplet is large, and if it is attempted to obtain a toner particle diameter of 3 μm to 6 μm by drying and solidifying it, the toner composition with an organic solvent is obtained. Needs to be diluted to a very dilute solution. In this case, a large amount of drying energy is required to obtain a fixed amount of toner, which is disadvantageous.

  Further, in the present embodiment, the row of discharge holes (see FIG. 1) in which the plurality of discharge holes 19 are arranged is the width direction (horizontal direction in FIG. 2) in the liquid column resonance liquid chamber 18 as shown in FIG. Are arranged in parallel. With such a configuration, more droplets can be ejected by one ejection operation, and thus the production efficiency is enhanced. Since the liquid column resonance frequency fluctuates depending on the arrangement of the discharge holes 19, it is desirable to appropriately determine the liquid column resonance frequency while confirming the discharge of the droplets.

FIGS. 3A to 3D are cross-sectional views illustrating various cross-sectional shapes that can be adopted as the cross-sectional shape of the discharge hole 19.
In the present embodiment, the cross-sectional shape of the discharge hole 19 is illustrated as being tapered such that the diameter decreases toward the outlet side as shown in FIG. can do.
The cross-sectional shape of the discharge hole 19 shown in FIG. 3A is a cross-sectional shape in which the diameter is narrowed while having a round shape (curved shape) from the inlet side to the outlet side of the discharge hole 19. In this cross-sectional shape, when the discharge hole thin film 41 constituting the bottom wall portion of the liquid column resonance liquid chamber 18 in which the discharge holes 19 are formed vibrates, the pressure applied to the liquid becomes maximum near the outlet of the discharge hole 19 Therefore, it is a preferable shape for stabilizing the discharge.
The cross-sectional shape of the discharge hole 19 shown in FIG. 3B is a cross-sectional shape having a tapered shape such that the diameter is narrowed at a constant angle from the inlet side to the outlet side of the discharge hole 19. The embodiment is adopted. In this cross-sectional shape, by being tapered, as in the cross-sectional shape shown in FIG. 3A, when the thin film 41 for discharge hole vibrates, the liquid is caught in the vicinity of the outlet of the discharge hole 19 The pressure can be increased. The taper angle 42 can be appropriately changed, but is preferably in the range of more than 60 ° and 90 ° or less. When the nozzle angle 24 is 60 ° or less, it is difficult for pressure to be applied to the liquid, and also the processing of the discharge hole thin film 41 becomes difficult. On the other hand, when the nozzle angle 24 is 90 °, the cross-sectional shape as shown in FIG. 3C is obtained, but pressure is unlikely to be applied near the outlet of the discharge hole 19. As 90 ° is the maximum value. When the taper angle 42 is larger than 90 °, pressure is not applied near the outlet of the discharge hole 19, and droplet discharge becomes very unstable.
The cross-sectional shape of the discharge hole 19 shown in FIG. 3D is a shape combining the cross-sectional shape shown in FIG. 3A and the cross-sectional shape shown in FIG. Thus, the cross-sectional shape may be changed stepwise.

Next, the mechanism of droplet formation by the liquid column resonance droplet forming unit 10 will be described.
First, the principle of the liquid column resonance phenomenon generated in the liquid column resonance liquid chamber 18 in the droplet discharge portion 11 shown in FIG. 1 will be described.
Assuming that the sound velocity of the toner component liquid in the liquid column resonance liquid chamber is "c" and the driving frequency given to the toner component liquid as the medium from the vibration generating means 20 is "f", the wavelength λ at which the liquid resonance occurs is And can be calculated from the following equation (1).
λ = c / f (1)

In the present embodiment, the side wall portion (opening side wall portion) of the liquid column resonance liquid chamber 18 in which the communication passage for communicating with the liquid common supply passage 17 is formed is the opposite side wall portion in which the communication passage is not formed ( It can be considered to be equivalent to (closed side wall). In this case, when the longitudinal length L of the liquid column resonance liquid chamber 18 coincides with an even multiple of one quarter of the wavelength λ, the vibration of the vibration generating means 20 causes the liquid in the liquid column resonance liquid chamber 18 to Resonant vibration occurs most efficiently. The liquid column resonance optimum condition at which such liquid column resonance occurs most efficiently can be expressed by the following equation (2). The liquid column resonance optimum condition shown in the above-mentioned formula (2) is similarly satisfied even in the state where both longitudinal side wall portions of the liquid column resonance liquid chamber 18 are completely opened.
L = (N / 4) × λ (2)

  On the other hand, when one of the longitudinal side walls of the liquid column resonance liquid chamber 18 is open and the other is closed, the longitudinal length L of the liquid column resonance liquid chamber 18 has a wavelength The liquid column resonance is most efficiently formed when it corresponds to an odd multiple of one quarter of λ. That is, the liquid column resonance optimum condition in this case is expressed by expressing “N” in the above equation (2) as an odd number.

The driving frequency f with the highest liquid column resonance efficiency is as shown in the following equation (3) from the above equation (1) and the above equation (2). However, in practice, since the liquid has a viscosity that attenuates the resonance, the vibration is not amplified infinitely, but has a Q value, and as shown in the equations (4) and (5) described later, The resonance also occurs at the frequency near the highest efficiency driving frequency f shown in (3).
f = N x c / (4L) (3)

FIGS. 4 (a) to 4 (d) are diagrams for explaining the state of the standing wave of the velocity distribution and pressure distribution generated in the liquid in the liquid column resonance liquid chamber 18 in the case of N = 1, 2, 3 FIG.
However, FIG. 4A is an example in the case where N = 1 and one of both longitudinal end portions of the liquid column resonance liquid chamber 18 is open and the other is closed. . FIG. 4B is an example in the case where N = 2 and both longitudinal ends of the liquid column resonance liquid chamber 18 are closed. FIG. 4C shows an example in which N = 2 and both longitudinal ends of the liquid column resonance liquid chamber 18 are open. FIG. 4D is an example of the case where N = 3 and one of both longitudinal ends of the liquid column resonance liquid chamber 18 is open and the other is closed.

5 (a) to 5 (c) are diagrams for explaining the state of the standing wave of the velocity distribution and pressure distribution generated in the liquid in the liquid column resonance liquid chamber 18 in the case of N = 4 and 5 when N = 4 and 5, respectively. FIG.
FIG. 5 (a) is an example where N = 4 and both longitudinal ends of the liquid column resonance liquid chamber 18 are closed. FIG. 5B is an example of the case where N = 4 and both longitudinal ends of the liquid column resonance liquid chamber 18 are open. FIG. 5C shows an example of the case where N = 5 and one of both longitudinal ends of the liquid column resonance liquid chamber 18 is open and the other is closed.

  In FIG. 4 and FIG. 5, the solid line is the standing wave of velocity, and the dotted line is the standing wave of pressure. The wave generated in the liquid in the liquid column resonance liquid chamber 18 is actually a compressional wave (longitudinal wave), but in FIGS. 4 and 5, this is represented in the form of a sine wave (cosine wave) . For example, looking at the velocity distribution in FIG. 4 (a), it can be intuitively understood that the amplitude of the velocity distribution is zero at the closed side wall that is closed and is the maximum at the open side wall. As it is easy to understand, I used sine wave notation here. The standing wave pattern differs depending on the open / close state (the combination pattern of the open end and the fixed end) of the longitudinally opposite side wall portions, so in FIG. 4 and FIG. The combination pattern of the open end and the fixed end not matching 18 is also described.

  Although the details will be described later, the end condition is determined by the state of the opening of the discharge hole 19 and the opening of the communication passage connecting the liquid column resonance liquid chamber 18 and the common liquid supply passage 17. In acoustics, at the open end (opening end), the moving speed of the medium (liquid) in the longitudinal direction is maximal, and the pressure is zero. On the other hand, at the fixed end (closed end), on the other hand, the moving speed of the medium becomes zero and the pressure becomes maximum. The fixed end (closed end) is considered as an acoustically hard wall, and assuming that the wave is completely reflected, if the end is ideally completely closed or opened, the superposition of the waves is as shown in FIG. And, it is considered that a standing wave as shown in FIG. 5 is generated. As in the case of the liquid column resonance liquid chamber 18 of the present embodiment, when the openings such as the discharge holes 19 and the communication passage exist, the number of the discharge holes 19, the position of the discharge holes 19, the size and the position of the communication passage, etc. Also, the standing wave pattern fluctuates. Therefore, the actual resonance frequency appears at a position deviated from the ideal resonance frequency obtained from the equation (3). However, even if there is such a deviation, there is no problem because the drive frequency may be appropriately adjusted while confirming the actual discharge condition.

  Using 1200 [m / s] as the sound velocity c of the liquid, the longitudinal length L of the liquid column resonance liquid chamber 18 is 1.85 [mm], and the wall portion exists at both ends in the longitudinal direction. In the case of the resonance mode of N = 2 equivalent to the model in which both ends are fixed ends, from the above equation (2), the ideal resonance frequency that causes the liquid in the liquid column resonance liquid chamber 18 to generate the liquid column resonance most efficiently is It is derived as 324 [kHz]. On the other hand, using 1200 [m / s] as the sound velocity c of the liquid, the longitudinal length L of the liquid column resonance liquid chamber 18 is 1.85 [mm], and wall portions exist at both ends. In the case of the resonance mode of N = 4 equivalent to the model in which both ends are fixed ends, from the above equation (2), the ideal resonance frequency that causes the liquid in the liquid column resonance liquid chamber 18 to generate the liquid column resonance most efficiently is It is led with 648 [kHz]. Thus, higher order resonances can be used even in the liquid column resonance liquid chamber 18 having the same configuration.

  In the liquid column resonance liquid chamber 18 of the present embodiment, the both ends in the longitudinal direction are configured to be equivalent to the closed end, or can be described as an acoustically soft wall under the influence of the opening of the discharge hole 19. It is preferable to increase the resonance frequency. However, the configuration is not limited thereto, and for example, a configuration may be adopted in which both longitudinal ends are equivalent to the open end. Here, the influence of the opening of the discharge hole 19 means that the acoustic impedance becomes small, and in particular, the compliance component becomes large. As shown in FIG. 1, the whole of the discharge hole 19 provided in the liquid column resonance liquid chamber 18 of the present embodiment is disposed close to one end side in the longitudinal direction (opposite to the common liquid supply path 17). Therefore, the one end side can also be regarded as an open end (open end) under the influence of the opening of the discharge hole 19. As a result, in the case where the longitudinal direction both end wall portions of the liquid column resonance liquid chamber 18 as shown in FIG. 4B and FIG. 5A are equivalent to the closed end, only the resonance mode in which both ends are fixed ends. Alternatively, it is possible to use a resonant mode in which one end is an open end and the other end is a fixed end.

  Further, the number of the discharge holes 19, the arrangement of the discharge holes 19, and the cross-sectional shape of the discharge holes 19 also become factors to determine the drive frequency, and the drive frequency can be appropriately determined accordingly. For example, as the arrangement of the discharge holes 19 is closer to one end in the longitudinal direction, the restraint by the wall of the liquid column resonance liquid chamber 18 becomes looser at the longitudinal end. Therefore, as the arrangement of the discharge holes 19 is closer to one end in the longitudinal direction, the end in the longitudinal direction becomes closer to the open end, and the drive frequency is changed to be higher. Further, for example, when the number of the discharge holes 19 is increased, the restraint by the wall portion of the liquid column resonance liquid chamber 18 becomes loose at one end in the longitudinal direction to which the arrangement of the discharge holes 19 is moved. The drive frequency is changed so as to be close to the above. In addition, for example, also when changing the cross-sectional shape of the discharge hole 19 or changing the dimension of the discharge hole 19, it is necessary to change a drive frequency.

When an alternating voltage is applied to the vibration generating means 20 at the driving frequency determined in this way, the piezoelectric element of the vibration generating means 20 is deformed according to the voltage fluctuation, and the diaphragm 22 is displaced thereby. As a result, vibration corresponding to the driving frequency is applied to the liquid in the liquid column resonance liquid chamber 18, and a liquid column resonance standing wave is generated in the liquid in the liquid column resonance liquid chamber 18. However, if the driving frequency at which the liquid column resonance standing wave is generated most efficiently is close, the liquid column resonance standing wave is generated. Specifically, when the distance between the longitudinal wall on the liquid common supply path 17 side and the discharge hole disposed closest to the liquid common supply path 17 is Le, the length of the Le and the liquid column resonance liquid chamber Use the length L between the direction walls. The range of the driving frequency f for generating the liquid column resonance standing wave can be defined, for example, by the following equations (4) and (5). By causing the vibration generating means 20 to vibrate using a drive waveform whose main component is the drive frequency f within the range determined by the equations (4) and (5), the liquid column resonance is induced to generate droplets. It is possible to properly discharge from the discharge hole 19. However, it is preferable that the ratio of L to Le is Le / L> 0.6.
N × c / (4 L) ≦ f ≦ N × c / (4 Le) (4)
N × c / (4 L) ≦ f ≦ (N + 1) × c / (4 Le) (5)

  According to the principle of the liquid column resonance phenomenon described above, in the present embodiment, a liquid column resonance pressure standing wave is formed in the liquid column resonance liquid chamber 18 shown in FIG. 1 and disposed in the liquid column resonance liquid chamber 18. A continuous droplet discharge is generated from the discharge hole 19. Therefore, it is preferable to dispose the discharge hole 19 at a position where the standing wave of pressure fluctuates the most, since the discharge efficiency becomes high and the drive voltage can be suppressed lower.

  Further, although one discharge hole 19 may be provided in one liquid column resonance liquid chamber 18, it is preferable from the viewpoint of productivity to arrange a plurality of discharge holes 19 in one liquid column resonance liquid chamber 18 as described above. Specifically, it is preferably between 2 and 100. If the number exceeds 100, it is necessary to set a high driving voltage to the vibration generating means 20 to appropriately discharge the droplets from the respective discharge holes 19, and the behavior of the piezoelectric element of the vibration generating means 20 is not good. It tends to be stable.

  When a plurality of discharge holes 19 are formed for one liquid column resonance liquid chamber 18, the pitch between the discharge holes is preferably 20 μm or more. When the pitch between the discharge holes is smaller than 20 μm, the probability that the droplets discharged from the adjacent discharge holes contact each other and become large droplets increases, and the particle size distribution of the toner is deteriorated. It is because the possibility is increased.

Next, the state of the liquid column resonance phenomenon generated in the liquid column resonance liquid chamber 18 in the droplet discharge unit 11 in the liquid column resonance droplet forming unit 10 will be described.
FIGS. 6A to 6D are explanatory views schematically showing the liquid column resonance phenomenon generated in the liquid column resonance liquid chamber 18.
The solid line in the liquid column resonance liquid chamber 18 in FIG. 6 indicates the velocity distribution obtained by plotting the velocity at any measurement position in the longitudinal direction of the liquid column resonance liquid chamber 18. The direction from the closed side wall portion on the left side in the drawing to the opening side wall portion on the right side in the drawing is positive, and the opposite direction is negative. The dotted line in the liquid column resonance liquid chamber 18 in FIG. 6 indicates the pressure distribution obtained by plotting the pressure value at an arbitrary measurement position in the longitudinal direction of the liquid column resonance liquid chamber 18. Positive pressure is positive with respect to atmospheric pressure, and negative pressure is negative.

  In the present embodiment, as shown in FIG. 1, the height h 1 from the bottom of the liquid column resonance liquid chamber 18 in the droplet discharge unit 11 to the lower end of the communication passage communicating with the common liquid supply passage 17 (= approximately 80 [μm] is set to about twice the height h2 (= about 40 [μm]) of the communication port. Therefore, it can be approximately considered that both ends in the longitudinal direction of the liquid column resonance liquid chamber 18 of the present embodiment are substantially fixed ends. 6 (a) to 6 (d) show temporal changes in velocity distribution and pressure distribution under such a concept.

  FIG. 6A shows a pressure waveform and a velocity waveform in the liquid column resonance liquid chamber 18 at the time of droplet discharge. At this time, the pressure becomes maximum at the liquid portion on the closed side wall portion side in the liquid column resonance liquid chamber 18, that is, the liquid portion in the liquid chamber region where the discharge hole 19 is provided (liquid near the discharge hole) . As a result, the meniscus pressure is increased and the liquid is pushed out from each discharge hole 19. Thereafter, as shown in FIG. 6B, the pressure of the liquid in the vicinity of the discharge hole 19 becomes smaller, and the droplet 21 is discharged from the discharge hole 19 by shifting in the direction of the negative pressure.

  Thereafter, as shown in FIG. 6C, the pressure of the liquid in the vicinity of the discharge hole 19 is minimized. From this time, replenishment of the toner component liquid 14 from the liquid common supply path 17 to the liquid column resonance liquid chamber 18 starts. Then, as shown in FIG. 6 (d), the pressure of the liquid near the discharge hole 19 gradually increases this time, and shifts in the direction of the positive pressure. At this point, the replenishment of the toner component liquid 14 is completed, and the pressure of the liquid near the discharge hole 19 of the liquid column resonance liquid chamber 18 is maximized again, as shown in FIG. 6A.

  As described above, in the liquid near the discharge hole 19 in the liquid column resonance liquid chamber 18, a standing wave is generated by the liquid column resonance by the high frequency driving of the vibration generating unit 20, and the pressure is most greatly fluctuated. The discharge hole 19 is disposed at a position corresponding to the antinode of the standing wave by the liquid column resonance. From this, the droplets 21 are continuously discharged from the discharge holes 19 according to the cycle of the belly.

  Next, an example of a configuration in which droplets are actually discharged 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 in FIG. 1 is 1.85 [mm] and N = 2. In addition, the first to fourth toner discharge holes are arranged at the antinode positions of N = 2 mode pressure standing waves, and laser shadowography is performed with a drive frequency of 340 [kHz] as a sine wave. A picture taken by the method is shown in FIG. As can be seen from the figure, ejection of droplets having a very uniform diameter and a substantially uniform velocity is realized. Further, FIG. 8 is a characteristic diagram showing droplet velocity frequency characteristics when driven with the same amplitude sine wave of drive frequencies of 290 [kHz] to 395 [kHz]. As can be seen from FIG. 8, in the first to fourth nozzles, when the drive frequency is around 340 [kHz], the discharge speed from each nozzle becomes uniform, and the maximum discharge speed is achieved. From this characteristic result, it is understood that uniform discharge is realized at the position of the antinode of the liquid column resonance standing wave in the second mode of the liquid column resonance frequency of 340 [kHz]. Further, from the characteristic result of FIG. 8, the droplet is between the droplet discharge velocity peak in the first mode of 130 [kHz] and the droplet discharge velocity peak in the second mode of 340 [kHz]. It can be seen that the frequency characteristic of the liquid column resonance standing wave characteristic of the liquid column resonance not to be ejected is generated in the liquid column resonance channel. The frequency of the power supplied to the piezoelectric element is preferably in the range of 100 to 1000 kHz. At frequencies lower than 100 kHz, the productivity of particles is low, and at frequencies higher than 1000 kHz, lateral resonance of the liquid column resonance liquid chamber tends to occur, resulting in uneven discharge.

FIG. 9 is a block diagram showing an example of the configuration of the piezoelectric element drive circuit 100 of the droplet discharge device according to the present embodiment. In FIG. 9, it is the structure of the power amplifier corresponding to a general high frequency, and applies the alternating voltage to the piezoelectric element of the vibration generation means used as a load. The vibration generating means is expressed as a capacitive load, and repeats discharge and charge based on the drive signal. The piezoelectric element drive circuit 100 includes a waveform generation unit 102 that generates a drive signal of an AC waveform applied to the piezoelectric element 101. In addition, the voltage on the output side of the piezoelectric element 101 for supplying the drive signal which is the output signal of the preamplifier 103 and the main up 104 and the main up 104 supplied to the piezoelectric element 101 by amplifying the drive signal outputted from the waveform generation means An oscilloscope 106 is provided as a voltmeter to measure. The drive signal output from the waveform generation means 102 is supplied to the positive terminal of the preamplifier 103 and amplified from the control signal (not shown) supplied from the negative terminal of the preamplifier 103 to a target pre-amplification value. The first drive signal is supplied to the positive terminal of the main up 104. In the main up 104, the second drive signal amplified to the target amplification value is supplied to the piezoelectric element 101 by the control signal from the negative electrode terminal and is supplied to the piezoelectric element 101 by the control signal from the control unit (not shown). As a result, charge and discharge of the piezoelectric element 12 are performed to vibrate. The oscilloscope 106 measures the peak value of the AC voltage on the output side of the piezoelectric element 101. The measured value is supplied to a drive control unit described later. Specifically, the voltage supplied to the input side of the piezoelectric element 101 decreases with the heat generation due to the resistance value R1 of the wiring resistance. Furthermore, the voltage on the output side of the piezoelectric element 101 is lowered due to the self-heating due to the dielectric loss due to the resistance R ₀ of the piezoelectric element 101 and the capacitor capacity C ₁ . The voltage on the output side of the piezoelectric element 101 can be measured accurately by measuring the voltage on the output side of the piezoelectric element 101 with the oscilloscope 106 having a large impedance to infinity. The difference between the measured voltage value on the output side of the piezoelectric element 101 and the target voltage value that has been measured is determined, and the voltage supplied to the input side of the piezoelectric element 101 by the waveform generation means 102 is controlled so that the difference becomes small. Do.

FIG. 10 is a block diagram showing another example of the configuration of the piezoelectric element drive circuit 100 of the droplet discharge device according to the present embodiment. In FIG. 10, the piezoelectric element drive circuit 100 has an oscillator 110 that generates a reference signal (common reference signal) Vs that defines the waveforms of control signals Vc1 and Vc2 that control the output of the drive signal applied to the piezoelectric element 101. doing. In addition, an FET drive circuit 111 as a control signal output unit that outputs two control signals to each of the high side FET 112 and the low side FET 113 based on the one reference signal (common reference signal) Vs is provided. To the output voltage V2 of the DC power source 114, and low FET113 for discharging high-side FET112 for charging are connected in series, the piezoelectric element via an inductor L to the middle point (connecting point) and the resistor _{R 1} 101 Is connected. The high side FET 112 and the low side FET 113 are controlled independently of each other by control signals Vc1 and Vc2 from the FET drive circuit 111, respectively. The FET drive circuit 111 generates control signals Vc1 and Vc2 based on the reference signal Vs. An FET drive circuit 111 generating a control signal Vc1 is connected to the gate as a control terminal of the high side FET 112, and an FET drive circuit 111 generating a control signal Vc2 is connected to a gate as a control terminal of the low side FET 113 There is.

In the piezoelectric element drive circuit 100 configured as described above, the phases of the control signals Vc1 and Vc2 are adjusted so that the high side FET 112 and the low side FET 113 are not simultaneously turned on. Assuming that the voltage applied to the piezoelectric element 12 is Vp, the high side FET 112 and the low side FET 113 are on / off controlled by the control signals Vc1 and Vc2 as shown in Table 1 below, for example. As a result, the voltage applied to the piezoelectric element 101 changes, charging / discharging of the piezoelectric element 12 is performed, and the piezoelectric element 101 vibrates. The ammeter 115 measures the DC current value of the DC power supply 114, and the voltmeter 116 measures the voltage value of the DC power supply 114. The oscilloscope 117 of the voltmeter measures the peak value of the AC voltage of the piezoelectric element 101. The measured value is supplied to a drive control unit described later. Specifically, the voltage on the output side of the piezoelectric element 12 decreases due to heat generation due to the wiring resistance (resistance value R ₁ ) or self-heating due to dielectric loss due to the resistance R ₀ of the piezoelectric element 101 and the capacitor capacitance C _1. . The voltage on the output side of the piezoelectric element 12 can be measured accurately by measuring this reduced voltage with the oscilloscope 106 having a large impedance of infinity. The difference between the measured voltage value on the output side of the piezoelectric element 12 that can be measured and the target voltage value is obtained, and the voltage V2 of the DC power supply 114 is controlled so that the difference becomes small. Alternatively, even by measuring the ammeter 115, the same control as described above is possible based on the measured value.

  When the driving of the high side FET 112 and the low side FET 113 is repeated at a constant period (frequency f), the voltage applied to the piezoelectric element 101 changes in a trapezoidal wave in a state of little rising noise.

FIG. 11 is a block diagram showing another example of the configuration of the piezoelectric element drive circuit 100 of the droplet discharge device according to the present embodiment. In FIG. 11, the drive signal generation circuit outputs a signal generation circuit 120 for outputting a charge / discharge pulse 121 for defining the charge / discharge timing of the piezoelectric element 101 as vibration generation means, and a voltage amplification circuit 122 for the charge / discharge pulse 121. have. In addition, based on the charge and discharge pulse 121, a push-pull connected NPN bipolar transistor (hereinafter referred to as "NPN transistor") 123 and a PNP bipolar transistor (hereinafter referred to as "PNP transistor") 124 are switched. A current amplification circuit that outputs a common drive signal COM that has been operated and amplified to the piezoelectric element 101 is provided. Here, the piezoelectric element 101 is represented as a capacitive load C1, and when the drive signal COM is applied, the piezoelectric element 101 repeats discharge and charge based on the drive signal COM. The ammeter 125 measures the DC current value of the DC power supply 114, and the voltmeter 126 measures the voltage value of the DC power supply 114. The oscilloscope 127 of the voltmeter measures the peak value of the AC voltage of the piezoelectric element 101. The measured value is supplied to a drive control unit described later. Specifically, the voltage on the output side of the piezoelectric element 12 decreases with heat generation due to the wiring resistance (resistance value R ₁ ) or self-heating due to dielectric loss due to the resistance R ₀ of the piezoelectric element 101 and the capacitor capacitance C ₁ . The voltage on the output side of the piezoelectric element 12 can be measured accurately by measuring this reduced voltage with the oscilloscope 106 having a large impedance of infinity. The difference between the measured voltage value on the output side of the piezoelectric element 12 that can be measured and the target voltage value is determined, and the voltage V2 of the DC power supply 124 is controlled so that the difference becomes small. Alternatively, even by measuring the ammeter 125, the same control as described above is possible based on the measured value.

  In the piezoelectric element drive circuit shown in FIGS. 9 to 11, any of known means can be used as the current measuring means and the voltage measuring means, but various oscilloscopes acquire voltage waveforms and output peak values as results. Means are easy to use in AC voltage measurement. Moreover, although measurement of an alternating current can use an oscilloscope similarly, measurement is possible by adding current detection means, such as a clamp meter. Further, depending on the form of the power amplification circuit, it is possible to use the DC voltage or DC current of the output from the DC power supply that supplies power as a representative value. Moreover, in the case of a general-purpose power supply, current or voltage may be output, and it is also possible to use this.

  Next, the configuration of the drive control unit in the droplet discharge device of the present embodiment will be described with reference to the drawings. FIG. 12 is a block diagram for explaining a schematic configuration of the drive control unit. 12 (a) is a block diagram for explaining the schematic configuration of the voltage control unit, FIG. 12 (b) is a block diagram for explaining the schematic configuration of the current control unit, and FIG. 12 (c) is for explaining the schematic configuration of the voltage control unit. Block diagram. The drive control unit of FIG. 12 performs feedback control. As the simplest control, the difference between the measurement value obtained by the current measurement means or the voltage measurement means and the target value at a constant time interval is confirmed. In the case of (target value)> (measurement value), the set value is minutely increased, and in the case of (target value) <(measurement value), control is performed by minutely reducing the set value.

  In the voltage control unit of FIG. 12A, the voltage of the set voltage value is applied from the output unit (not shown) of the comparison adjustment unit 202 to the input side of the vibration generation unit 203 based on the set voltage value 201 set by the host device. Applied. The voltage on the output side of the vibration generating means 203 according to the applied voltage is measured by the voltage measuring means 204, for example, the oscilloscope 106 of FIG. 9, the oscilloscope 117 of FIG. 10 or the oscilloscope 127 of FIG. The control unit (not shown) of the comparison adjustment means 202 calculates the difference between the measured voltage value and the preset target voltage value, and the control unit of the comparison adjustment means 202 outputs the difference so that the difference becomes small. Output control signal to the unit. The above feedback control is performed.

  In the current control unit of FIG. 12 (b), the current of the set current value is supplied to the input side of the vibration generation unit 213 from the output unit (not shown) of the comparison adjustment unit 212 based on the set current value 211 set by the host device. Supplied. The current (clamp current value) on the output side of the vibration generating means associated with the supplied current is measured by the current measuring means 214, for example, the ammeter 115 of FIG. 10 or the ammeter 125 of FIG. The control unit (not shown) of the comparison adjustment unit 212 calculates the difference between the measured current value and the preset target current value, and the control unit of the comparison adjustment unit 202 outputs the difference so that the difference becomes small. Output control signal to the unit. The above feedback control is performed.

  In the power control unit of FIG. 12C, the power of the set power value is supplied from the output unit (not shown) of the comparison adjustment unit 222 to the input side of the vibration generation unit 223 based on the set power value 221 set by the host device. Supplied. The power on the output side of the vibration generating means associated with the supplied power is measured by the voltage measuring means / current measuring means 224, for example, the ammeter 115 of FIG. 10, the voltmeter 116, or the ammeter 125 of FIG. measure. The control unit (not shown) of the comparison adjustment means 222 calculates the difference between the measured power value and the preset target power value, and the control unit of the comparison adjustment means 202 outputs the difference so that the difference becomes small. Output control signal to the unit. The above feedback control is performed.

FIG. 13 is a schematic view showing an example of a toner production apparatus for carrying out the toner production method according to the present embodiment.
The toner manufacturing apparatus 300 mainly includes the above-described liquid column resonance droplet forming unit 310, a drying and collecting unit 320, and a toner component liquid replenishment unit 330.

  The toner component liquid replenishment unit 330 is provided with a toner component liquid tank 332 storing the toner component liquid 331. The toner component liquid tank 332 is connected to the liquid column resonance droplet forming unit 310 via the toner component liquid supply flow path 333. A liquid circulation pump 334 for pressure-feeding the toner component liquid 331 in the toner component liquid supply channel 333 is connected to the toner component liquid supply channel 333. By driving the liquid circulation pump 334, the toner component liquid 331 in the toner component liquid tank 332 is supplied to the liquid column resonance droplet forming unit 310 through the toner component liquid supply flow path 333.

  Further, the toner component liquid tank 332 is connected to the liquid column resonance droplet forming unit 310 via the liquid return pipe 335. Among the toner component liquids 331 supplied from the toner component liquid supply flow path 333 to the liquid column resonance liquid droplet forming unit 310, those which have not been replenished to the liquid column resonance liquid chamber of the liquid column resonance liquid droplet forming unit 310 are The circulation pump 334 is driven to return to the toner component liquid tank 332 through the liquid return pipe 335.

  In the present embodiment, a pressure measuring device P1 is provided in the toner component liquid supply flow path 333 and a pressure measuring device P2 is provided in the dry collection unit 320. The pressure of liquid supply to the liquid column resonance droplet forming unit 310 and the pressure in the drying and collecting unit 320 are managed based on the measurement results of these pressure measuring devices P1 and P2. At this time, if the pressure of the pressure measuring device P1 is larger than the pressure of the pressure measuring device P2, the toner component liquid 331 may leak out from the discharge hole. Conversely, if the pressure of the pressure measuring device P1 is smaller than the pressure of the pressure measuring device P2, gas may enter the liquid column resonance droplet forming unit 310 and the discharge may stop. Therefore, it is desirable that the pressure of the pressure measuring device P1 and the pressure of the pressure measuring device P2 be approximately equal.

  The drying and collecting unit 320 is provided with a chamber 321, and the liquid column resonance droplet forming unit 310 is installed in the chamber 321. A descending air flow (conveying air flow) 323 is fed into the chamber 321 from the conveying air flow introduction port 322, and the droplets 21 discharged from the liquid column resonance droplet forming unit 310 are not only gravity but also by the downward air flow 323. Are also transported downward. The droplets transported downward in the chamber 321 dry and solidify during transportation, are discharged from the collection outlet 324, are sent to the solidified particle collection means 325, and are collected. The particles collected by the solidified particle collection means 325 are then sent to the drying means 326 which performs secondary drying processing as necessary.

  When the discharged droplets come in contact with each other before drying, a phenomenon called coalescence occurs in which the droplets coalesce into one large particle, and the toner particle size distribution spreads. Therefore, in order to obtain toner particles having a narrow particle size distribution, it is necessary to secure the distance between the discharged droplets. However, the ejected droplets have a constant initial velocity but gradually stall due to air resistance. As a result, droplets discharged later may catch up with the droplets that have stalled, which may cause coalescence. Since such a coalescence phenomenon occurs regularly, if the particles are collected, the particle size distribution will be seriously deteriorated. In order to prevent such a bonding phenomenon, in the present embodiment, the falling air flow prevents the drop in the velocity of the droplets and prevents the droplets from contacting each other.

  Although the direction of the transport air flow (downdraft air flow 323) in the present embodiment is directed downward, a transport air flow that is directed in the lateral direction with respect to the droplet discharge direction can also be adopted. However, in this case, it is desirable to form the transport airflow so that the trajectories of the droplets transported by the transport airflow from the discharge holes do not overlap. The direction of the carrier air flow may not be horizontal to the droplet discharge direction, but may be oblique to the droplet discharge direction, but it has an angle such that the discharged droplets are separated. Is desired.

  Further, in the present embodiment, both the prevention of coalescence and the conveyance to the solidified particle collecting means are realized by the descending air flow, but the first air flow for preventing the coalescence and the solidified particle collecting means You may form separately with the 2nd air flow for conveying to. In this case, it is desirable that the flow velocity of the first air flow be equal to or greater than the moving velocity of the droplets at the time of discharge. If the flow velocity of the first air flow is slower than the droplet movement speed at the time of discharge, there is a possibility that the function of preventing contact between droplets, which is the purpose of the first air flow, may not be sufficiently performed. With respect to the other characteristics of the first air flow, conditions may be appropriately added so that the droplets do not contact each other, and they do not have to be the same as the characteristics of the second air flow. For example, a chemical substance that promotes the solidification of the droplets may be mixed into the first air flow, or a physical action may be performed to promote the solidification of the droplets.

  The downdraft of the present embodiment may be, for example, laminar flow, swirl flow, turbulent flow or the like. The kind of gas which comprises downdraft is not specifically limited, Even if it is air, what used nonflammable gas, such as nitrogen, may be used. In addition, the temperature of the downdraft can be appropriately adjusted, and it is desirable that there is no fluctuation at the time of production. In addition, means may be provided in the chamber to change the flow state of the downdraft. The downdraft may be used not only to prevent the droplets from contacting each other, but also to prevent the droplets from adhering to the inner wall of the chamber.

  As shown in FIG. 13, in the present embodiment, in the case where the amount of residual solvent contained in the toner particles collected by the solidified particle collection means 325 is large, a drying means, as necessary, to reduce this. Secondary drying is performed at 326. As secondary drying, general known drying means such as fluidized bed drying and vacuum drying can be used. When the organic solvent remains in the toner, not only toner characteristics such as heat resistance storage stability, fixing ability, charging characteristics, etc. fluctuate with time, but the organic solvent is volatilized at the time of heat fixation at the time of image forming operation. Therefore, the possibility of adversely affecting the user, various devices in the image forming apparatus, and peripheral devices is increased, and it is desirable to perform sufficient drying.

Hereinafter, the toner manufactured in the present embodiment will be described.
The toner produced in the present embodiment contains at least a resin, a colorant and a wax, and as necessary, a charge control agent, an additive and other components.

First, the toner component liquid used in the present embodiment will be described.
The toner component liquid is in a liquid state in which the toner component is dissolved or dispersed in the solvent, or the solvent may not be contained as long as it is a liquid under the conditions to be discharged, and a part or all of the toner component is melted. It is mixed in the state and is in the liquid state. As the toner material, if the above-mentioned toner component liquid can be prepared, the same one as a known electrophotographic toner can be used. Such a toner component liquid is discharged from the liquid column resonance droplet forming unit so as to be minute droplets, and the minute droplets are dried and solidified and collected by the solidified particle collection means 325. Toner particles are produced.

As said resin, a binder resin is mentioned at least.
There is no restriction | limiting in particular as said binder resin, Although the resin used normally can be selected suitably and can be used, For example, a styrene-type monomer, an acryl-type monomer, a methacryl-type monomer etc. Vinyl polymer, copolymer of these monomers or two or more types, polyester polymer, 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 a property of the binder resin, it is desirable to dissolve in a solvent, and it is desirable to have conventionally known performance except this characteristic.
In the molecular weight distribution of the binder resin according to GPC (gel permeation chromatography), it is preferable in terms of the fixing property of the toner and the offset resistance that at least one peak is present in a region of a molecular weight of 3,000 to 50,000. In addition, a binder resin in which components having a molecular weight of 100,000 or less are 60 to 100 [%] is also preferable as a THF soluble component, and a binder having at least one peak in a region having a molecular weight of 5,000 to 20,000 Resin is more preferred. It is preferable that the resin having an acid value of 0.1 to 50 [mg KOH / g] of the binder resin is 60 [mass%] or more.
In the present embodiment, the acid value of the binder resin component of the toner composition is measured in accordance with JIS K-0070.

  As a magnetic material that can be used in the present embodiment, known materials used for electrophotographic toner can be used. For example, (1) iron oxide including 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 with metals such as lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten and vanadium, and (3) mixtures thereof, and the like. The magnetic material can also be used as a colorant. The amount of the magnetic material used is preferably 10 to 200 parts by mass, and more preferably 20 to 150 parts by mass with respect to 100 parts by mass of the binder resin. As a number average particle diameter of these magnetic bodies, 0.1-2 [micrometers] are preferable, and 0.1-0.5 [micrometers] are more preferable. The above-mentioned number average diameter can be determined by measuring a photograph magnified and photographed by a transmission electron microscope with a digitizer or the like.

There is no restriction | limiting in particular as said coloring agent, Usually used resin can be selected suitably and can be used.
The content of the coloring agent 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 exemplary embodiment can also be used as a master batch combined with a resin. The masterbatch is for dispersing the pigment in advance, and may not be used if sufficient dispersion of the pigment is obtained. The masterbatch is generally one in which the pigment is dispersed in the resin into hardness by applying high shear to the pigment and the resin. As the binder resin to be kneaded with the production or masterbatch of the masterbatch, conventionally known ones can be used. These may be used singly or in combination of two or more.

  As a usage-amount of the said masterbatch, 0.1-20 mass parts is preferable with respect to 100 mass parts of binder resin. A dispersing agent may be used to enhance the dispersibility of the pigment during masterbatch production. From the viewpoint of pigment dispersibility, it is preferable that the compatibility with the binder resin is high, and known ones can be used, and specific commercial products include “Adisper PB 821” and “Adisper PB 822” (Ajinomoto Fine Techno Co., Ltd.) Company), "Disperbyk-2001" (made by Bick Chemie), "EFKA-4010" (made by EFKA), etc. are mentioned.

  The dispersant is preferably blended in the toner at a ratio of 0.1 to 10% by 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 it is more than 10% by mass, the chargeability under high humidity may be reduced. It is preferable that it is 1-200 mass parts with respect to 100 mass parts of coloring agents, and, as for the addition amount of the said dispersing agent, it is more preferable that it is 5-80 mass parts. When the amount is less than 1 part by mass, the dispersibility may be lowered, and when the amount is more than 200 parts by mass, the chargeability may be lowered.

The toner component liquid used in the present embodiment contains a wax together with a binder resin and a colorant.
The wax is not particularly limited, and those which are usually used can be appropriately selected and used. For example, low molecular weight polyethylene, low molecular weight polypropylene, polyolefin wax, microcrystalline wax, paraffin wax, sazole wax, etc. Aliphatic hydrocarbon waxes, oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax or block copolymers thereof, candelilla waxes, carnauba waxes, plant waxes such as wax, jojoba wax, beeswax, lanolin Animal waxes such as spermaceti wax, mineral waxes such as ozokerite, ceresine, and peteralat, waxes composed mainly of fatty acid esters such as montanic acid ester wax and castor wax, fatty acid esters such as deacidified carnauba wax part Those deoxygenated all are and the like.

  The melting point of the wax is preferably 70 to 140 ° C., and more preferably 70 to 120 ° C., in order to balance the fixing property and the offset resistance. If the temperature is less than 70 ° C., the blocking resistance may decrease, and if the temperature exceeds 140 ° C., the anti-offset effect may not be easily exhibited. As a total content of the said wax, 0.2-20 mass parts is preferable with respect to 100 mass parts of binder resin, and 0.5-10 mass parts is more preferable. In this embodiment, the temperature of the peak top of the maximum peak of the endothermic peak of the wax measured in DSC (differential scanning calorimetry) is taken as the melting point of the wax. As a DSC measurement device of the wax or toner, it is preferable to measure 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 embodiment uses a curve that is measured when the temperature is raised at a temperature rate of 10 [° C./min] after the temperature rise and fall once to obtain the previous history.

  The toner according to the exemplary embodiment includes, as other additives, protection of latent image carrier and carrier, improvement of cleaning performance, adjustment of thermal characteristics, electric characteristics and physical characteristics, adjustment of resistance, adjustment of softening point, improvement of fixing rate Inorganic fine powders such as various metal soaps, fluorosurfactants, dioctyl phthalate, tin oxide, zinc oxide, carbon black, antimony oxide etc., titanium oxide, aluminum oxide, alumina etc. A body etc. can be added as needed. These inorganic fine powders may be hydrophobized as required. In addition, lubricants such as polytetrafluoroethylene, zinc stearate and polyvinylidene fluoride, abrasives such as cesium oxide, silicon carbide and strontium titanate, anti-caking agents, white particles and black particles having a reverse polarity to that of toner particles Can also be used in small amounts as a developability improver.

  These additives are used for controlling the amount of charge, etc., and the surface thereof is a silicone varnish, various modified silicone varnishes, silicone oils, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, and other organic compounds. It is also preferable to treat with a treating agent such as a silicon compound, or various treating agents. Inorganic fine particles can be preferably used as the additive. As the inorganic fine particles, for example, known ones such as silica, alumina, titanium oxide and the like can be used.

  Other than these, polymer particles, such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, dispersion polymerization, methacrylic acid ester, acrylic acid ester copolymer, silicone, polycondensation system such as benzoguanamine, nylon, thermosetting resin Polymer particles according to

  Such an external additive can be made hydrophobic by the surface treatment agent, and can 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 an alkyl fluoride group, an organic titanate coupling agent, an aluminum coupling agent, a silicone oil, a modified silicone oil, Are preferably mentioned.

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 proportion of the inorganic fine particles used 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 and the primary transfer medium include fatty acid metal salts such as zinc stearate, calcium stearate, stearic acid, and polymethyl methacrylate. Polymer fine particles produced by soap-free emulsion polymerization such as fine particles and polystyrene fine particles can be mentioned. The fine polymer particles preferably have a relatively narrow particle size distribution and a volume average particle diameter of 0.01 to 1 μm.

Example 1
Hereinafter, an embodiment of the present invention (hereinafter, this embodiment will be referred to as “embodiment 1”) will be described.
The formulation of the toner component liquid used in Example 1 is shown below. The droplet discharge conditions are as described in the above embodiment.
First, a dispersion of carbon black 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 a stirring blade. As this pigment dispersant, Agisper PB 821 (manufactured by Ajinomoto Fine Techno Co., Ltd.) was used. The obtained primary dispersion is finely dispersed by a strong shear force using a bead mill (LMZ type manufactured by Ashizawa Finetech, zirconia bead diameter 0.3 [mm]), and aggregates of 5 [μm] or more are completely formed. The secondary dispersion removed was prepared.

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

  Next, a toner component liquid having the following composition to which a resin as a binder resin, the above-mentioned colorant dispersion and the above-mentioned wax dispersion were added was prepared. 100 parts by mass of a polyester resin as a binder resin, 30 parts by mass of the colorant dispersion, and 30 parts by mass of a wax dispersion, and 840 parts by mass of ethyl acetate are stirred for 10 minutes using a mixer having a stirring blade. It was dispersed uniformly. Shock due to solvent dilution did not cause aggregation of pigment or wax particles.

Next, conditions of the toner manufacturing apparatus used in the first embodiment will be described. The configuration of the toner manufacturing apparatus is as described in the embodiment.
In the liquid column resonance droplet forming unit 310 of this embodiment, the length L between the longitudinal ends of the liquid column resonance liquid chamber 18 in FIG. 1 is 1.85 [mm], N = 2 resonance mode, First to fourth discharge holes 19 aligned along the longitudinal direction are disposed at the antinode positions of the pressure standing wave in the N = 2 mode. The driving frequency was set to 340 [kHz] in accordance with the liquid resonance frequency.

  In the drying and collecting unit 320 of this embodiment shown in FIG. 13, the inner diameter of the chamber 321 is φ400 mm and the height is cylindrically fixed at 2000 mm, and the upper end and the lower end are narrowed. Shape. The diameter of the conveying air flow inlet at the upper end is φ50 [mm], and the diameter of the conveying air flow outlet at the lower end is φ50 [mm]. The liquid column resonance droplet forming unit 310 is arranged at the height of 300 [mm] from the upper end in the chamber 321 and at the center of the chamber 321 in the horizontal direction. The carrier air flow (downdraft air 323) was nitrogen of 10.0 [m / s] and 40 [° C.]. A cyclone collector was used as the solidified particle collection means 325.

  The piezoelectric element drive circuit of Example 1 of FIG. 9 was used as the piezoelectric element drive circuit used in the toner manufacturing apparatus of the present embodiment, and control was performed to make the peak value of the alternating voltage constant by the oscilloscope 106. The control time interval was controlled to 1 [seconds], and the allowable voltage range was controlled to ± 0.4 [V] with respect to the set voltage 8.0 [V].

The evaluation of the toner produced by Example 1 was performed as follows.
The prepared toner component liquid 331 is discharged for 1 hour using the toner manufacturing apparatus of the first embodiment of FIG. 13, and the droplets are dried and solidified in the chamber 321, and toner particles obtained by a cyclone collector are captured. It was collected and stored in a toner storage container. The toner was removed from the toner storage container, and the toner was collected. The toner particle size distribution of each toner was measured using a flow type particle image analyzer (FPIA-3000 manufactured by Sysmex Corporation) under the measurement conditions shown below. The production and measurement of the toner as described above were repeated three times, and the evaluation was performed using the average value.

The measurement by a flow type particle image analyzer removes fine dust through a filter, and as a result, the measurement range (for example, circle equivalent diameter 0.60 [μm]) in water of 10 ^-3 [cm ³ ] Several droplets of a nonionic surfactant (preferably, Contaminone N manufactured by Wako Pure Chemical Industries, Ltd.) are added to 10 ml of water having a particle number of not less than 159.21 [μm] and not more than 20 particles. Furthermore, 5 [mg] of the measurement sample is added, and dispersion treatment is performed for 1 minute under the conditions of 20 [kHz] and 50 [W] / 10 [cm ³ ] with UH-50 manufactured by STM Corporation. Furthermore, dispersion treatment is performed for a total of 5 minutes, and the sample concentration of the measurement sample is 400 to 8000 [number / ^10-3 · cm ³ ] (for particles of the measurement equivalent circle diameter range) using a sample dispersion of 0 The particle size distribution of particles having a circle-equivalent diameter of 60 μm or more and less than 159.21 μm is measured.

  The sample dispersion passes through a flat, flat, transparent flow cell (having a thickness of about 200 μm) (which extends along the flow direction). A strobe and a CCD camera are mounted on opposite sides of the flow cell to form an optical path that crosses and passes through the thickness of the flow cell. While the sample dispersion is flowing, strobe light is illuminated at intervals of 1/30 seconds to obtain an image of the particles flowing through the flow cell, so that each particle has a constant 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.

  The equivalent circle diameter of 1200 or more particles can be measured in about 1 minute, and the number based on the equivalent circle diameter distribution and the percentage (number of particles) of particles having the defined 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 for one octave). In the actual measurement, the particles are measured in the range of equivalent circle diameter of 0.60 [μm or more and less than 159.21 [μm].

  In Example 1, as a result of this measurement, the average of the volume average particle diameter (Dv) of the obtained toner particles (average of three measurements. The same applies hereinafter) is 5.5 [μm], and the number average particle is The average of the diameter (Dn) was 5.2 [μm], and the average of Dv / Dn was 1.05. Furthermore, as a result of measuring the particle diameter one hour after the start of collection, the volume average particle diameter (Dv) and the number average particle diameter (Dn) which are exactly the same as the above result were obtained.

Example 2
Next, another embodiment of the present invention (hereinafter, this embodiment will be referred to as “embodiment 2”) will be described.
In the second embodiment, the piezoelectric element drive circuit of FIG. 10 is used as the piezoelectric element drive circuit used in the toner manufacturing apparatus of the present embodiment, and control is performed to make the peak value of alternating voltage constant by the oscilloscope 117. The toner was collected for 1 hour under the same conditions as in Example 1. The average of the volume average particle diameter (Dv) of the obtained toner particles is 5.5 [μm], and the average of the number average particle diameter (Dn) is 5.1 [μm], and the average of Dv / Dn is Was 1.08. Furthermore, as a result of measuring the particle diameter one hour after the start of collection, the volume average particle diameter (Dv) and the number average particle diameter (Dn) which are exactly the same as the above result were obtained.

[Example 3]
Next, still another embodiment of the present invention (hereinafter, this embodiment will be referred to as “third embodiment”) will be described.
In the present example 3, the piezoelectric element drive circuit of FIG. 11 is used as the piezoelectric element drive circuit used in the toner manufacturing apparatus of the present embodiment, and control is performed such that the peak value of AC voltage is made constant by the oscilloscope 127. The toner was collected for 1 hour under the same conditions as in Example 1. The average of the volume average particle diameter (Dv) of the obtained toner particles is 5.5 [μm], and the average of the number average particle diameter (Dn) is 5.1 [μm], and the average of Dv / Dn is Was 1.08. Furthermore, as a result of measuring the particle diameter one hour after the start of collection, the volume average particle diameter (Dv) and the number average particle diameter (Dn) which are exactly the same as the above result were obtained.

Example 4
Next, still another embodiment of the present invention (hereinafter, this embodiment will be referred to as “embodiment 4”) will be described.
In the fourth embodiment, the piezoelectric element drive circuit of FIG. 10 is used as the piezoelectric element drive circuit used in the toner manufacturing apparatus of the present embodiment, and control is performed to make the voltage value constant with the voltmeter 116. The toner was collected for 1 hour under the same conditions as in Example 1. The average of the volume average particle diameter (Dv) of the obtained toner particles is 5.6 [μm], and the average of the number average particle diameter (Dn) is 5.2 [μm], and the average of Dv / Dn is Was 1.08. Furthermore, as a result of measuring the particle diameter one hour after the start of collection, the volume average particle diameter (Dv) and the number average particle diameter (Dn) which are exactly the same as the above result were obtained.

[Example 5]
Next, still another embodiment of the present invention (hereinafter, this embodiment will be referred to as “Embodiment 5”) will be described.
In the fifth embodiment, the piezoelectric element drive circuit of FIG. 10 is used as the piezoelectric element drive circuit used in the toner manufacturing apparatus of the present embodiment, and control is performed so that the current value is made constant by the ammeter 115. The toner was collected for 1 hour under the same conditions as in Example 1. The average of the volume average particle diameter (Dv) of the obtained toner particles is 5.6 [μm], and the average of the number average particle diameter (Dn) is 5.3 [μm], and the average of Dv / Dn is Was 1.06. Furthermore, as a result of measuring the particle diameter one hour after the start of collection, the volume average particle diameter (Dv) and the number average particle diameter (Dn) which are exactly the same as the above result were obtained.

[Example 6]
Next, still another embodiment of the present invention (hereinafter, this embodiment will be referred to as “embodiment 6”) will be described.
In the sixth embodiment, the piezoelectric element drive circuit of FIG. 11 is used as the piezoelectric element drive circuit used in the toner manufacturing apparatus of the present embodiment, and control is performed to make the voltage value constant by the voltmeter 126. The toner was collected for 1 hour under the same conditions as in Example 1. The average of the volume average particle diameter (Dv) of the obtained toner particles is 5.6 [μm], and the average of the number average particle diameter (Dn) is 5.3 [μm], and the average of Dv / Dn is Was 1.06. Furthermore, as a result of measuring the particle diameter one hour after the start of collection, the volume average particle diameter (Dv) and the number average particle diameter (Dn) which are exactly the same as the above result were obtained.

[Example 7]
Next, still another embodiment of the present invention (hereinafter, this embodiment will be referred to as “the seventh embodiment”) will be described.
In the seventh embodiment, the piezoelectric element drive circuit of FIG. 11 is used as the piezoelectric element drive circuit used in the toner manufacturing apparatus of the present embodiment, and control is performed so as to make the current value constant by the ammeter 125; The toner was collected for 1 hour under the same conditions as in Example 1. The average of the volume average particle diameter (Dv) of the obtained toner particles is 5.5 [μm], and the average of the number average particle diameter (Dn) is 5.3 [μm], and the average of Dv / Dn is Was 1.04. Furthermore, as a result of measuring the particle diameter one hour after the start of collection, the volume average particle diameter (Dv) and the number average particle diameter (Dn) which are exactly the same as the above result were obtained.

  As described above, also in the first to seventh embodiments, after one hour has elapsed from the start of the discharge operation, and even after one hour after the start of collection, the coalescence or splitting of the droplets due to the fluctuation of the discharge capability As a result, the same narrow toner particle size distribution as in the initial stage was obtained.

Comparative Example 1
In Comparative Example 1, the piezoelectric element drive circuit of FIG. 11 is used as the piezoelectric element drive circuit used in the toner manufacturing apparatus of the present embodiment, and the stabilization control as in the present embodiment is not performed. The toner was collected for 1 hour under the same conditions as in the above. The average of the volume average particle diameter (Dv) of the obtained toner particles is 5.5 [μm], and the average of the number average particle diameter (Dn) is 5.2 [μm], and the average of Dv / Dn is Was 1.05. Furthermore, as a result of measuring the particle diameter one hour after the start of collection, the average of the volume average particle diameter (Dv) of the toner particles is 4.8 [μm], and the average of the number average particle diameter (Dn) Of 4.2 [μm], and the average of Dv / Dn was 1.14. In Comparative Example 1, it was found that the diameter of the collected particles decreased with the passage of time, and it was difficult to form a high quality image after 1 hour. In this comparative example, due to the change of the discharge capacity with the lapse of time, the coalescence and splitting of the droplets are caused, and the same narrow toner particle size distribution as in the initial stage can not be obtained.

What has been described above is an example, and the present invention has unique effects in each of the following modes.
(Aspect 1)
The toner component liquid 14 such as the liquid in the liquid column resonance liquid chamber 18 such as the liquid chamber in which the discharge hole 19 is formed is vibrated by the piezoelectric element 101 as a vibration generating means through the vibration plate 22 to be a discharge hole In the droplet discharge apparatus that discharges the toner component liquid 14 from the liquid container 19 into droplets, a waveform generation unit 102 as a supply unit that supplies voltage or current to the input side of the piezoelectric element 101 as a vibration generation unit, a DC power supply 114 , 124 and ammeters 115 and 125 such as measuring means for measuring the voltage or current on the output side of the piezoelectric element 101, voltmeters 116 and 126, oscilloscopes 106, 117 and 127, and the piezoelectric measured by the measuring means By the supply means, the difference between the voltage measurement value or the current measurement value on the output side of the element 101 and the preset target voltage value or target current value becomes small. Controlling the voltage or current supplied to the input side of the electric element.
According to this, as described in the above-described embodiment, the heat generated by the resistance of the wiring electrically connecting the piezoelectric element 101 and the supply means causes the original power supplied to the input side of the piezoelectric element 101 to be Part is consumed, and the voltage or current supplied to the input side of the piezoelectric element 101 is reduced. Furthermore, due to the self-heating of the piezoelectric element 101, the voltage or current of the original output side of the piezoelectric element decreases with respect to the voltage or current supplied to the input side of the piezoelectric element 101. By measuring the voltage or current on the output side of the piezoelectric element 101, it is possible to detect a substantial voltage or current on the output side of the piezoelectric element 101 which is reduced by heat generation due to wiring resistance or self heat generation of the piezoelectric element 101. . The voltage or voltage supplied to the input side of the piezoelectric element 101 by the supply means so that the voltage measurement value or current measurement value obtained by measuring the voltage or current on the output side of the piezoelectric element 101 becomes substantially equal to the target voltage value or target current value. Control the current. As a result, it is possible to offset the reduced discharge capacity by the reduction of the substantial voltage or current. Therefore, stable droplet discharge can be performed.
(Aspect 2)
In (Aspect 1), the power measuring unit is provided on a part of the wiring electrically connected to the piezoelectric element 101. According to this, as described in the above embodiment, it is possible to detect the substantial voltage or current on the input side of the piezoelectric element 101 which is reduced by the heat generation in the wiring resistance. Then, if it is possible to measure the voltage or current on the output side of the piezoelectric element 101, the substantial voltage measurement value or current measurement value on the input side of the piezoelectric element 101 reduced by heat generation in the wiring resistance, and the measured piezoelectric element From the voltage measurement value or the current measurement value on the output side of 101, it is possible to detect the substantial voltage or current on the output side of the piezoelectric element reduced by the self-heating of the piezoelectric element 101.
(Aspect 3)
(Aspect 1) or (Aspect 2)
The frequency of the power supplied to the piezoelectric element 101 is in the range of 100 to 1000 [kHz]. According to this, as described in the above embodiment, discharge is performed by high frequency vibration, and a narrow particle size distribution can be obtained.
(Aspect 4)
In any of (Aspect 1) to (Aspect 3), vibration is applied to the liquid in the liquid column resonance liquid chamber in which the discharge hole is formed by the vibration generating means to form a standing wave by liquid column resonance, The liquid is discharged from the discharge holes formed in the region which becomes the antinode of the standing wave to form droplets. According to this, as described in the above embodiment, continuous and stable discharge can be performed, and a narrow particle size distribution can be obtained.
(Aspect 5)
A liquid column resonance droplet forming unit 310 as a droplet discharge means for discharging a particle component-containing liquid containing particle components from a discharge hole, and a solidifying and drying method for solidifying and drying droplets of the particle component-containing liquid discharged from the discharge hole A toner manufacturing apparatus 300 of a particle manufacturing apparatus including a drying and collecting unit 320 as a unit, wherein the liquid droplet discharging apparatus according to any one of (Aspect 1) to (Aspect 4) is used as a liquid droplet ejection means. According to this, as described in the above embodiment, it is possible to manufacture particles such as toner having a uniform particle diameter.

Reference Signs List 100 piezoelectric element drive circuit 101 piezoelectric element 102 waveform generation means 103 preamplifier 104 main up 105 resistance 106 oscilloscope 110 oscillator 111 FET drive circuit 112 high side FET
113 low side FET
114 DC power supply 115 Ammeter 116 Voltmeter 117 Oscilloscope 120 Signal generation circuit 121 Charge and discharge pulse 122 Voltage amplification circuit 123 NPN transistor 124 PNP transistor 125 Ammeter 126 Voltmeter 127 Oscilloscope 201 Setting voltage value 202 Comparison adjustment means 203 Vibration generation means 204 Voltage value 205 Voltage measurement means 211 Set current value 212 Comparison adjustment means 213 Vibration generation means 214 Current value 215 Current measurement means 221 Installation electric power value 222 Comparison adjustment means 223 Vibration generation means 224 Voltage value / current value 225 Voltage measurement means / current measurement Means 300 Toner manufacturing apparatus 310 Liquid column resonance droplet forming unit 320 Drying and collecting unit 321 Chamber 322 Conveying air flow inlet 323 Downdrafting air 324 Collection outlet 325 Solidified particle collecting means 326 Drying hand 330 toner component replenishment unit 331 toner component liquid 332 toner component liquid tank 333 toner component liquid supply passage 334 liquid circulating pump 335 fluid return pipe

Patent No. 3786034 gazette Patent No. 3786035 gazette Japanese Patent Application Laid-Open No. 57-201248 JP, 2011-212668, A

Claims (4)

A particle production method, comprising discharging a particle component-containing liquid containing particle components from a discharge hole, and then solidifying and drying droplets of the particle component-containing liquid discharged from the discharge hole,
The liquid in the liquid chamber in which the discharge holes are formed is vibrated by the vibration generating means through the diaphragm, and the liquid is discharged from the discharge holes to form droplets, using a droplet discharge method.
In the droplet discharge method,
While supplying voltage or current to the input side of the vibration generating means,
Measuring the measured value of the voltage or current on the output side of the vibration generating means;
The voltage supplied to the input side of the vibration generating means so that the measured voltage measured value or current measured value on the output side of the vibration generating means becomes smaller from the target voltage value or the target current value. Or control the current ,
A transport air stream is formed so that the trajectories of the droplets being transported do not overlap in the lateral direction with respect to the droplet ejection direction from the ejection holes, and the droplets of the particle component-containing liquid ejected from the ejection holes A method for producing particles, comprising solidifying and drying . In the particle production method according to claim 1,
The frequency of the electric power supplied to the said vibration generation means is a range of 100-1000 [kHz], The particle manufacturing method characterized by the above-mentioned. In the particle production method according to claim 1 or 2,
The liquid within the liquid column resonance liquid chamber in which the discharge hole is formed is vibrated by the vibration generating means to form a standing wave by liquid column resonance, and is formed in a region which becomes an antinode of the standing wave A particle manufacturing method characterized in that the liquid is discharged from the discharge hole to form droplets. In the particle production method according to any one of claims 1 to 3,
A method of producing particles , wherein the vibration generating means vibrates at a predetermined frequency .