JP2001235037A - Exhaust valve and method of making for toner for developing electrostatic image using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent imperfect closure of an exhaust valve and formation of coarse particles by eliminating granules which may cling to the exhaust valve element of the exhaust valve of a collecting device for the granules such as toners or to the interior wall of an exhaust port and which may be crimped by the fitting part of the exhaust valve element and the interior wall of the exhaust port. SOLUTION: An annular pressure gas ejection nozzle 15 is provided near the upper pole of the exhaust valve element 13 of the exhaust valve of a double damper located in the lower portion of the granule collecting device, and the exhaust valve element and the interior wall of the exhaust port are cleaned by compressed gas ejected from the ejection nozzle as the exhaust valve element closes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of powders such as toner for developing electrostatic images used for developing electrostatic latent images formed by electrophotography or electrostatic recording.
The present invention relates to a discharge valve used for the transfer and collection device.

[0002]

2. Description of the Related Art Conventionally, a method for producing a toner used in electrophotography and electrostatic photography of electrostatic recording is to mix, melt and knead raw materials such as a binder resin and a colorant, cool the mixture, and jet the mixture using compressed air. After finely pulverized by a pulverizer such as a mill, the particles are adjusted to particles of a desired size by a classifier or the like utilizing a gas flow, and an additive is further added as necessary, and the mixture is filled into a container such as a bottle or a cartridge. .

[0003] In these steps, gas transfer is generally used at various places to transfer toner. Generally, a cyclone or a bag filter is used as a device for separating the gas-transferred toner from the gas and collecting the gas, and a discharge valve body is combined in series and double below the cyclone or the bag filter. A double damper is provided, and the toner collected by the cyclone or the bag filter is accumulated on the upper part of the double damper above the cyclone or the bag filter. To remove this toner, first open the upper discharge valve with the lower discharge valve of the double damper closed, let the toner fall on the upper part of the lower discharge valve, and then close the upper discharge valve. After that, open the lower discharge valve. This series of operations is usually performed for 3 seconds to 2 seconds.
By frequently repeating the cycle of 0 seconds, the toner can be taken out while maintaining the state of the airflow inside the pipe.

[0004]

However, the following problems occur during the operation of the above-described discharge valve. That is, it is inevitable that the particulate matter remaining in the discharge port and the discharge valve body of the discharge valve is sandwiched between the inner wall of the discharge port and the discharge valve body due to frequent opening and closing operations of the discharge valve body. These accumulated powdered fluids deteriorate the airtightness of the discharge valve, so that the cyclone cannot maintain the state of the airflow in the pipe and lowers its collection efficiency. On the other hand, the toner compressed and solidified by the discharge valve body separates and mixes with the toner as a product, which is one of the causes of generation of coarse particles. In particular, in the case of a double damper discharge valve installed in a cyclone for collecting products, which is installed at the latter stage of the classification process and external addition process, etc. Is mixed, and is fatal. The removal of the coarse particles once mixed in requires enormous amount of time and labor and must be avoided.

For this reason, it is necessary to periodically stop the apparatus, open an inspection port, and clean the discharge port and the discharge valve body. This cleaning operation involves danger and is one of the factors that lower the production efficiency, and a mechanism for preventing the particulate matter from sticking to the discharge valve is required.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, suppress generation of coarse particles, and stably maintain the collection efficiency of a collection device such as a cyclone for a long time. To provide a discharge valve.

Further, an object of the present invention is to solve the above-mentioned problems of the prior art, to greatly reduce the frequency of cleaning the particulate discharge valve and to avoid the danger, and to provide an electrostatic charge developing device. An object of the present invention is to provide a method for efficiently manufacturing a toner.

[0008]

That is, the present invention relates to a discharge valve having an opening / closing mechanism installed at a discharge port of a collecting device for separating and recovering a powder fluid being conveyed from a gas flow by a gas flow. In conjunction with the opening / closing operation of the valve element, the discharge valve at the time of closing the discharge port by the compressed gas from the compressed gas ejection nozzle from the start of the closing operation of the discharge valve element to the completion of the closing operation. A discharge valve having a mechanism for cleaning a contact portion or a press-contact portion between a body and an inner wall of a discharge port. More preferably, the compressed gas ejection nozzle has a shape in which a compressed gas ejection port is provided on the outer wall of a hollow pipe formed into an annular shape, around the axis of the annular shape, and on the circumference. In addition, the discharge valve is characterized in that the compressed gas ejection nozzle whose circumferential axis coincides with the axis of the ring is provided near the upper portion of the discharge valve body.

[0009] Here, the shape of the jet port of the compressed gas may be circular or other shapes as long as they are installed on the circumference, or may be along the circumference. A series of slits may be used.

[0010] Further, in the manufacturing process of an electrostatic image developing toner used for developing an electrostatic latent image formed by an electrophotographic system or an electrostatic recording system, the particles transported by gas are collected. For a discharge valve of a double damper attached to a lower part of a cyclone or the like, a mechanism for cleaning a discharge valve body and a discharge port with compressed gas from the compressed gas ejection nozzle in conjunction with a closing operation when the discharge valve is closed. The present invention relates to a discharge valve characterized by having a discharge valve. The opening and closing operation of the discharge valve body of these discharge valves includes a discharge valve that opens and closes by rotating the discharge valve body by a driving device, or more preferably a pneumatic drive device, so as to facilitate cleaning by the compressed gas. The valve body is once moved linearly, such as descending, and then rotated by 90 degrees to discharge the powder and the like. After an arbitrary opening time, the discharge valve body is again rotated by 90 degrees to the original state, and then returned to the original position. It is preferable that the discharge valve has a mechanism for closing the discharge port by performing a linear motion such as a rise in the pressure.

For example, in the vicinity of the upper pole of such a discharge valve body, there is provided a compressed gas discharge nozzle formed into a ring shape having a discharge port with the above hollow ring, and the discharge valve body is interlocked with the closing operation of the discharge valve body. Is rotated by 90 degrees after an arbitrary opening time, and from the point when linear movement such as ascent is started until the discharge valve body contacts the discharge port, a compressed gas is externally introduced into the discharge nozzle to be discharged, so that the discharge gas is constantly discharged. It has been found that the discharge port and the discharge valve body can be in close contact with each other in a clean state, which is particularly suitable as a method for producing a toner for developing an electrostatic image.

As described above, the discharge valve according to the present invention can be in contact with the discharge port and the discharge valve body in a clean state at all times during operation, so that toner adheres to the discharge port or the discharge valve body. As a result, the hermeticity is maintained for a long time, and the inherent collection efficiency of the cyclone is maintained substantially without causing the problematic change. Become. Furthermore,
Since there is no need to clean the discharge valve except for changing the part number, there is no danger, and continuous operation is possible, so that production efficiency is improved.

In the present invention, the discharge valve body is a movable plug body which is driven by an external driving device, is pressed against and detached from the discharge port or the inner wall of the discharge port, and seals or opens the discharge port. It is. On the other hand, the discharge valve is a whole of a device that performs a discharge operation including a discharge valve body and the above-described compressed gas ejection nozzle or the like, or various mechanisms necessary for their operation.

The method and the apparatus for cleaning the discharge port using the compressed gas jet nozzle used in the discharge valve of the present invention are used not only for the apparatus for collecting the particulates but also for the apparatus for widely transferring and discharging the particulates. Can.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention includes the following inventions and embodiments.

1. A discharge valve that is provided at a discharge port of a collection device that separates and recovers the powder fluid being conveyed from the gas flow by the gas flow, and has an opening / closing mechanism that seals and opens the discharge port with a discharge valve body; A discharge valve having a mechanism for cleaning a contact portion between the discharge valve body and the discharge port when the discharge port is sealed with a compressed gas in conjunction with a closing operation of the body.

2. On the outer wall of a hollow pipe processed into an annular shape, a compressed gas having a center on the axis of the annular shape and a jet of compressed gas installed on a circumference such that the axis coincides with the axis of the annular shape. 2. The discharge valve according to the above item 1, wherein the ejection nozzle is provided near an upper portion of the discharge valve body.

3. 3. The discharge valve according to claim 2, wherein the discharge valve opens and closes only by the rotational movement of the discharge valve body about one axis.

4. The discharge valve once makes the discharge valve body move linearly, and then rotates 90 degrees to discharge the granular material, and after any opening time, rotates the discharge valve body again to the original state by 90 degrees,
3. The discharge valve according to the above item 2, wherein the discharge valve has a mechanism for closing the discharge port by continuously linearly moving to the original position.

[5] A powder fluid collecting device having the discharge valve according to the above 1, 2, 3, or 4.

6. A step of melt-kneading a mixture containing at least a binder resin and a colorant, a step of cooling and solidifying the kneaded product, a step of pulverizing the solidified product, a step of classifying the pulverized product, and In the method for manufacturing a toner for developing an electrostatic charge image including a step of externally adding an additive, the discharge valve of the collecting device that collects the gas-transferred powdery material includes
A method for producing a toner for developing an electrostatic charge image, comprising using the discharge valve described in 2, 3, or 4.

The discharge valve according to the present invention is used in the process of producing an electrostatic image developing toner used for developing an electrostatic latent image formed by an electrophotographic system or an electrostatic recording system.
It is suitably used as a discharge valve of a double damper attached to a lower part of a collecting device such as a cyclone for collecting the gas-transported powder.

The details of the structure of the discharge valve or the operation thereof will be described below with reference to the drawings. 2 and 3 are schematic views of a double damper using the discharge valve of the present invention as one of the embodiments of the present invention. Both figures have a structure in which valve bodies having the same structure are connected in series vertically, and FIG. 2 is a side view and FIG. 3 is a side view from a direction perpendicular to FIG. In order to make the internal structure easy to understand, the upper side of the exhaust valves arranged in tandem is shown with the side wall inside the exhaust valve with the side wall removed.

The operation when the discharge valve of the present invention is used will be described below.

In the discharge valve shown in FIGS. 2 and 3, the discharge valve 13 is once lowered by the air drive device 12, and then rotated by 90 degrees to discharge the powder and the like. The body 13 is rotated 90 degrees to its original state, and then raised to close the outlet. In the discharge valve body that performs such an operation, a hollow pipe is formed into an annular shape in the vicinity of the upper part of the portion where the discharge valve body contacts the discharge port at the discharge port, and on the periphery thereof, around the axis of the ring. Is provided with a compressed gas ejection nozzle 15 having an ejection port, and in synchronization with the closing operation of the ejection valve body, the ejection valve body 13 rotates 90 degrees after an arbitrary opening time, and the ejection valve body 13 starts to rise from the time when the ascending starts. Compressed gas is introduced from the outside until compressed gas
By making it eject more, the discharge port and the discharge valve body 13 are brought into close contact with each other in a clean state at all times. Here, the shape of the discharge valve body itself or the shape of the discharge port inner wall of a portion fitted with the discharge valve body may be other than those illustrated, but for details thereof, the operation as the discharge valve body described above is possible.
Any material can be used without particular limitation as long as it has good adhesion after the outlet is sealed.

The compressed gas may be injected before the closing operation is started separately from the closing operation, that is, before the start of the linear movement. If the injection is performed during the operating period after entering, the compressed gas is injected while the relative distance between the compressed gas ejection nozzle and the discharge valve is changed, and the compressed gas is injected from a different direction of the discharge valve. Corresponds to the discharge valve body, so that more efficient cleaning can be performed.

The gas used for the compressed gas injection nozzle is as follows:
Normally, air is used, but depending on the powder to be transferred, another gas such as an inert gas may be used, or the temperature of the gas may be controlled.

Here, the jet port of the compressed gas may be either the small-diameter jet port shown in FIG. 6 or the slit-shaped jet port shown in FIG. , The slit-shaped ejection port is more preferable.

Further, the direction of jetting the compressed gas can be adjusted by the direction of the opening of the jet port. The opening direction can be defined by the angle between the axis of the ring of the ejection nozzle and the normal to the opening of the ejection port.However, when the outer diameter of the ring is smaller than the inner wall of the discharge port, the compressed gas is It is preferred that the gas is ejected from the ring at an appropriate angle and spread outward.

The portion to be cleaned by the compressed gas jet nozzle may extend over the entire discharge valve or the discharge port, but it is preferable that the compressed gas be intensively applied to the portion where the powder fluid is easily deposited and fixed. If such a portion is a discharge valve body, the fitting portion between the discharge valve body and the inner wall of the discharge port at the time of sealing, or the crimping portion of the discharge valve body to the inner wall of the discharge port, or the discharge valve body It is a sliding portion with the inner wall of the discharge port, and if it is on the discharge port side, it is a corresponding portion on the inner wall side of the discharge port that comes into contact with a portion where the powder fluid on the discharge valve body is likely to accumulate and stick.

More specifically, for example, a so-called 125
When the double damper of A is used, a hollow pipe with an outer diameter of 10 mmφ is connected to an outer diameter of 110 mmφ for a discharge port of 125 mmφ.
The compressed gas ejection nozzle processed into a ring shape is disposed above and very close to the discharge valve body within a range that does not hinder the driving of the discharge valve body. The spout is formed by forming a small-diameter spout as shown in FIG. 6 from a hole diameter of 0.1 mmφ to 3.0 mmφ, preferably 0.3 mmφ.
Or a slit nozzle as shown in FIG. 7 is opened with a slit width of 0.1 mm to 3.0 mm, preferably 0.3 mm to 2.0 mm.

On the other hand, FIGS. 4 and 5 show a discharge valve body for opening and closing the discharge port only by the rotational movement of the discharge valve body, and a compression for cleaning the crimping portion when the discharge valve body and the discharge port are closed. A side view of a discharge valve including a gas ejection nozzle and a double damper in which two of the discharge valves are connected in series, and another side view from a direction different from the side view by 90 degrees are shown. The discharge valve shown in FIGS. 2 and 3 is a discharge valve in which the discharge valve body and the inner wall portion of the discharge port fitted therewith do not relatively slide, whereas those shown in FIGS. The discharge valve is a type of discharge valve in which the discharge valve body and the inner wall of the discharge port may partially rub against each other. As long as the discharge valve body itself basically rotates, the discharge valve body or the portion of the inner wall of the discharge port fitted with the discharge valve body may have any shape.

Details of the operation of the double damper including these discharge valves, and details of the compressed gas injection nozzle,
It is the same as the case of the double damper shown in FIGS. 2 and 3 except that the movement at the time of opening and closing of the discharge valve body is only a rotational movement.

FIG. 1 shows a schematic diagram of a pulverizing system as an example using these discharge valves. A double damper having a discharge valve of the type shown in FIGS. 2 and 3 is installed immediately below the cyclone 3 as shown in FIG. A double damper of the type shown in FIGS. 4 and 5, which opens and closes only by the rotation of the discharge valve body, is installed immediately below the bag filter 9 as shown in FIG. Is collected and discharged.
The compressed gas supply system connected to the double damper 10 and its control system are omitted in FIG.
It is set in the same way as the double damper.

The condition at that time is, for example, an original pressure of 0.98.
The compressed gas of MPa is adjusted from 0.1 MPa to 0.6 MPa, preferably from 0.2 MPa to 0.5 MPa by the pressure control valve, introduced into the compressed gas ejection nozzle, and synchronized with the closing operation of the discharge valve body, the double damper of 4 In the case of the discharge valve, the compressed gas is ejected from the time when the discharge valve body rotates 90 degrees after an arbitrary opening time and starts to rise until the discharge port is closed, thereby remaining at the discharge port and the discharge valve body. Clean the powder.

In the case of the discharge valve of the double damper shown in FIG. 10, the compressed gas is ejected from the time when the discharge valve body starts rotating 90 degrees after an arbitrary opening time to the time when the discharge port is closed. Clean the powder fluid remaining at the outlet and discharge valve body.

Since the discharge port and the discharge valve body thus cleaned come into close contact with each other, no crimped material is generated due to the powder particles being caught between the discharge port and the discharge valve body.
The cleaning work with the opening of the inspection port is eliminated, so that dangerous work can be eliminated, and the production efficiency can be improved.

With respect to the toner using the discharge valve according to the present invention in the manufacturing process and the manufacturing method, the composition of the toner is not particularly limited, and a known composition is used. In the manufacturing process other than the process using the collecting device using the discharge valve of the present invention, a known manufacturing method and apparatus can be used.

The method for producing a toner for developing an electrostatic image is, for example, a kneading step of mixing and melting and kneading auxiliary agents such as a charge controlling agent and a release agent in addition to a binder resin and a colorant. A pulverizing step in which the melt-kneaded product is cooled, coarsely pulverized by an appropriate means as necessary, and finely pulverized by a pulverizer such as a jet mill using compressed air. A classifying step in which the pulverized toner is further adjusted to particles of a desired size by a classifier or the like utilizing an air flow. The method further includes an external addition step of adding an additive to the toner as needed, and a filling step of filling the container such as a bottle or a cartridge with the toner.

The discharge valve according to the present invention is used at any place during the process of producing powder such as toner, and transports the gas-transferred powder while maintaining the state of air flow. It can be used to discharge to any place using a collecting device, but for the purpose of collecting powders in the process close to the final process, the place where the target is discharged, that is, for example, the final product is collected It is particularly useful when used immediately below a cyclone.

The toner used in the present invention is not particularly limited and may be a known toner. Examples of the binder resin include polystyrene, styrene-acrylate copolymer, polyester resin, epoxy resin, butyral resin, and the like. Xylene resins, coumaroindene resins and the like can be mentioned. As the colorant, for example, as a black pigment, carbon black, furnace black, aniline black, etc.
Benzidine pigments (CI291090, CI291095) and the like as yellow pigments for full-color toners, xanthene pigments (astrakunoxin) as red pigments,
Blue pigments include phthalocyanine pigments (CI Pigment Blue 15, CI Solvent Blue 70), and thioindigo pigments (CI78865) and azo lake pigments (CI15850).

As the charge controlling agent, for example, those used for imparting a positive charge include nigrosine dyes, quaternary ammonium salts, triphenylmethane dyes, and the like. Used are acid dyes containing a heavy metal such as Cr.

Further, in the toner for heat roll fixing, various waxes are used as necessary as an anti-offset auxiliary agent for enhancing the releasing effect for the purpose of preventing troubles due to toner adhesion to the heat roll. Natural waxes such as carnauba wax, montanic acid ester wax, candelilla wax, rice wax, ibotaro wax and the like, and polyolefin waxes such as high pressure polyethylene and polypropylene can be used.

The mixing ratio is, for example, 100 parts by weight of the binder resin as mentioned above, and 1 to 1 parts of the coloring agent.
15 parts by weight, a charge control agent of 0.1 to 5 parts by weight, and an offset preventing agent of 0.5 to 10 parts by weight can be used. Further, if necessary, inorganic fine particles as a fluidity-providing agent may also be used in an amount of 0.01 to 10%.
Parts by weight can be used.

[0045]

EXAMPLES The powdery material supply apparatus of the present invention and the method for producing a toner for electrostatic charge development using the same will be described in the following examples, but the present invention is not limited to these examples.

Example 1 Styrene-acrylic copolymer 100 parts by weight (softening point; 110 ° C., glass point transfer; 60 ° C.) Carbon black 10 parts by weight Polypropylene 4 parts by weight Cr-containing dye 2 parts by weight

The above components were mixed, melt-kneaded in a twin-screw extruder, cooled immediately, crushed to 1 mm to 2 mm by a coarse crusher, and then subjected to fine crushing, classification, and external addition to 10 μm. The toner was created. In these steps, the discharge valve according to the present invention was used for a double damper immediately below the cyclone for collecting products in the pulverizing step and the classifying step.

The discharge valve has a diameter of 10 as shown in FIG.
A pipe having a diameter of 110 mm was machined into a ring shape having a diameter of 110 mm, a slit having a width of 0.5 mm was formed at the center of the ring-shaped pipe, and placed in the discharge port as shown in FIG. In addition, as a compressed gas introduction condition to the compressed gas ejection nozzle,
The discharge valve body is moved from the discharge port open state shown by the dotted line in FIG.
The solenoid valve 6 of FIG. 1 is set so as to be open from the time when it rotates 0 degrees and returns to the position shown by the solid line until it comes into contact with the discharge port, and the compressed gas of the original pressure of 0.8 MPa Was reduced to 0.4 MPa by the pressure control valve 5 and used.

The double damper using the exhaust valve adjusted in this manner, which is a double damper, is used immediately below the cyclone for collecting products in the pulverizing process and immediately below the cyclone for collecting products in the classifying process. The operation was performed in 5 to 6 seconds. After 3 hours, 6 hours, and 24 hours from the start of both processes, the process equipment was stopped, and the discharge port and the discharge valve body were visually observed from the inspection port. Did not. No coarse particles were detected by the quality inspection of the product.

(Comparative Example 1) The solenoid valve 6 in FIG. 1 was changed so as not to operate the discharge valve immediately below the product collection cyclone in the classification step, so that the compressed gas did not enter the compressed gas ejection nozzle. Except for the above, an electrostatic image developing toner was manufactured in the same manner as in Example 1. Visual observation from the inspection port of the double damper as in Example 1 showed that the pressure-bonded product of the toner was already in the discharge port and the discharge valve body after three hours of inspection. Inspection after 6 hours further revealed that the pressure-bonded material was further increased, and the discharge amount of the product per unit time was extremely reduced. This is because the sealing performance was reduced due to the crimped material attached to the discharge port and the discharge valve body, causing a leak phenomenon, and the cyclone collection efficiency was reduced. Six hours later, coarse particles were confirmed by quality inspection of the product.

[0051]

By using the discharge valve according to the present invention for the cyclone for collecting the particulates transported by gas, the discharge port and the discharge valve body are always cleaned during the operation of the discharge valve and come into contact in a clean state. Therefore, the toner does not adhere to the discharge port and the discharge valve body, one of the causes of the generation of coarse particles can be eliminated, and the quality can be improved. Also,
The cyclone's hermeticity is maintained for a long time, and the inherent collection efficiency of the cyclone is maintained substantially without causing the change in question. Furthermore, at the time of manufacturing the same part number, there is no need to perform a cleaning operation, so that danger can be eliminated and, at the same time, continuous operation of the apparatus is possible, thereby improving production efficiency.

[Brief description of the drawings]

FIG. 1 schematically shows a pulverizing system as an example using a discharge valve according to the present invention.

FIG. 2 schematically shows a double damper using a discharge valve of a type in which a discharge valve body is once lowered and then rotated by 90 degrees to discharge a powder fluid, among the double dampers using the discharge valve according to the present invention. It is a side view.

FIG. 3 is a side view showing the double damper shown in FIG. 2 from an angle different from that of FIG. 2 by 90 degrees.

FIG. 4 is a side view schematically showing a double damper that uses a discharge valve of a type that discharges a powder fluid only by the rotation of a discharge valve body among double dampers using a discharge valve according to the present invention.

5 is a side view showing the double damper shown in FIG. 4 from an angle different from that of FIG. 4 by 90 degrees.

FIG. 6 is an example of a compressed gas ejection nozzle whose ejection port has a circular opening.

FIG. 7 is an example of a compressed gas ejection nozzle having an ejection port formed of a slit.

[Explanation of symbols]

DESCRIPTION OF REFERENCE NUMERALS 1 Crushed material inlet 2 Crusher 3 Cyclone 4 Double damper (use of discharge valve that rotates 90 degrees to discharge after discharge valve descends) 5 Pressure control valve 6 Solenoid valve 7 Solenoid valve control box 8 Compressed gas Source 9 Bag filter 10 Double damper (Use of a discharge valve whose discharge valve body discharges only by rotational movement.) 11 Blower 12 Drain valve drive device 13 Discharge valve body 14 Double damper body 15 Compressed gas jet nozzle 16 Inspection port

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 9/087 G03G 9/08 381 F-term (Reference) 2H005 AA08 AB04 3H052 AA02 BA02 BA35 CD09 EA06 EA16 3H054 AA04 BB02 BB30 CD14 GG05 GG14 4D053 AA03 AB01 BA01 BB02 BC01 BD04 CD05 CD06 CD22 CD25 4F201 AA13 AB12 AB18 AC04 AH81 AL10 AL17 BA02 BC01 BC12 BC15 BC37 BL05 BL23 BL42 BL45 BL48 BN30 BN32 BN36 BQ05 BQ21 BQ35 BQ44

Claims (6)

[Claims] 1. A discharge valve having an opening / closing mechanism installed at a discharge port of a collecting device for separating and recovering a powder fluid being conveyed from a gas flow by a gas flow, and closing and opening the discharge port by a discharge valve element. A discharge valve having a mechanism for cleaning a contact portion between the discharge valve body and the discharge port when the discharge port is sealed with a compressed gas in conjunction with the closing operation of the discharge valve body. . 2. On the outer wall of a hollow pipe processed into an annular shape,
A compressed gas ejection nozzle provided with a compressed gas ejection port is provided near the upper portion of the discharge valve body on a circumference having a center on the axis of the ring and the axis coinciding with the axis of the ring. The discharge valve according to claim 1, wherein: 3. The discharge valve according to claim 2, wherein the discharge valve opens and closes only by the rotational movement of the discharge valve body about one axis. 4. The discharge valve causes the discharge valve body to linearly move once,
A mechanism for rotating the discharge valve body by 90 degrees continuously to discharge the powder and granules, rotating the discharge valve body again by 90 degrees to the original state after an arbitrary opening time, and then linearly moving back to the original position to block the discharge port. The discharge valve according to claim 2, wherein the discharge valve is a discharge valve. 5. A powder-fluid collecting device having the discharge valve according to claim 1, 2, 3, or 4. 6. A step of melt-kneading a mixture containing at least a binder resin and a colorant, a step of cooling and solidifying the kneaded product, a step of pulverizing the solidified product, a step of classifying the pulverized product, A method for producing a toner for developing an electrostatic charge image, which comprises a step of externally adding an additive to the granulated particles, wherein a discharge valve of a collecting device for collecting the gas-transferred granules is provided.
3. A method for producing a toner for developing an electrostatic charge image, comprising using the discharge valve described in 3 or 4.