JP7654358B2 - Toner manufacturing method and manufacturing device - Google Patents

Description

The present invention relates to a method and an apparatus for producing toner used in electrophotography, electrostatic recording, electrostatic printing, and toner jet methods.

In recent years, full-color electrophotographic copiers have become widespread and are beginning to be applied to the printing market. In the printing market, there is a growing demand for high speed, high image quality, and high productivity while being compatible with a wide range of media (paper types). In the case of toner, a toner with a sharp particle size distribution stabilizes the chargeability, which in turn stabilizes the developability and transferability, thereby achieving high image quality.
Toners manufactured through melt-kneading and pulverization processes have the advantage of good pigment dispersion and high image quality, but mechanical pulverization devices (see Patent Documents 1 and 2, etc.), which are often used as pulverization devices, have the disadvantage that it is difficult to sharpen the particle size distribution compared to toners manufactured by polymerization methods, etc.

JP 2005-21768 A JP 2011-237816 A

The object of the present invention is to solve the above-mentioned problems associated with mechanical grinding devices used as grinding devices in toner production, and to provide a toner production method and production device that produces a sharp particle size distribution.

The present invention relates to a method for producing a toner, comprising a step of finely pulverizing a material to be pulverized by a pulverizing means,
The crushing means is
A powder supply mechanism for supplying the material to be pulverized;
a stator having a plurality of protrusions and recesses on an inner circumferential surface;
a rotor attached to a central rotating shaft and having a plurality of protrusions and recesses on an outer circumferential surface;
A powder discharge port for discharging the finely pulverized material;
having
the stator contains the rotor, and the rotor is disposed so that a surface of the stator and a surface of the rotor face each other with a predetermined gap therebetween;
The recesses and protrusions on the inner peripheral surface of the stator and the outer peripheral surface of the rotor are formed along the axial direction of the central rotating shaft,
the concaves and convexes on the inner peripheral surface of the stator and the concaves and convexes on the outer peripheral surface of the rotor are not interdigitated with each other in a direction perpendicular to the central rotation axis direction,
The material to be pulverized is pulverized in a pulverization region formed by a gap between the stator and the rotor by the rotation of the rotor,
The material to be pulverized is accelerated and sprayed from one end of the central rotating shaft in the axial direction by a powder supply nozzle, which is the powder supply mechanism, and supplied to the pulverizing region;
The finely pulverized material is discharged from the powder discharge port provided on the other end side of the central rotating shaft in the axial direction.
The present invention relates to a method for producing a toner.
The present invention also provides a toner manufacturing apparatus having a step of finely pulverizing a material to be pulverized by a pulverizing means, comprising:
The crushing means is
A powder supply mechanism for supplying the material to be pulverized;
a stator having a plurality of protrusions and recesses on an inner circumferential surface;
a rotor attached to a central rotating shaft and having a plurality of protrusions and recesses on an outer circumferential surface;
A powder discharge port for discharging the finely pulverized material;
having
the stator contains the rotor, and the rotor is disposed so that a surface of the stator and a surface of the rotor face each other with a predetermined gap therebetween;
The recesses and protrusions on the inner peripheral surface of the stator and the outer peripheral surface of the rotor are formed along the axial direction of the central rotating shaft,
the concaves and convexes on the inner peripheral surface of the stator and the concaves and convexes on the outer peripheral surface of the rotor are not interdigitated with each other in a direction perpendicular to the central rotation axis direction,
The material to be pulverized is pulverized in a pulverization region formed by a gap between the stator and the rotor by the rotation of the rotor,
The powder supply nozzle, which is the powder supply mechanism, is a means for accelerating and spraying the material to be pulverized from one end side of the axial direction of the central rotation shaft along the axial direction to supply the material to the pulverization region,
The finely pulverized material is discharged from the powder discharge port provided on the other end side of the central rotating shaft in the axial direction.
The present invention relates to a toner manufacturing apparatus characterized in that

The present invention provides a toner manufacturing method and manufacturing device that produces a sharp particle size distribution.

FIG. 1 is a diagram of a conventional mechanical grinding device. FIG. 2 is a diagram of a mechanical grinding device used in the present invention. FIG. 1 is a diagram of an interlocking tooth grinding device. FIG. 1 is a diagram of a jet milling device.

In mechanical grinding, the coarsely ground material is pulverized by applying impact mainly to the rotor rotating at high speed. Conventionally, the coarsely ground material was fed onto cold air introduced from an inlet on one side of the rotor's shaft. However, with this method, all particle sizes of coarsely ground material were crushed, which made it easy for the material to become over-pulverized, resulting in a broad particle size distribution. This was particularly noticeable with the jet mill grinding method. Conventionally, after this grinding process, a classification process was carried out to remove fine powder and maintain a constant particle size distribution, but there is room for further improvement in the area in which a sharper particle size distribution is required even in the grinding process.

As a result of the inventors' investigations into improving this point, they succeeded in achieving a sharp particle size distribution in the grinding process by using a grinding technique in which the coarsely crushed material is accelerated and sprayed by a powder supply mechanism along the axial direction from one end of the central rotating shaft to a processing section (grinding area) formed by opposing stators and rotors in a mechanical grinder.

The mechanism by which the grinding method of the present invention makes it possible to sharpen the particle size distribution is not yet clear, but the inventors hypothesize the following.

In the mechanical grinding machine of the present invention, the coarsely crushed material is accelerated and sprayed by the powder supply mechanism along the axial direction from one end of the central rotating shaft. This configuration is believed to reduce the number of collisions of the coarsely crushed material with the rotor and stator. In other words, fine powder components of the coarsely crushed material are more susceptible to the effects of accelerated spray and are carried farther. As a result, it is believed that collisions of the fine powder with the rotor and stator are reduced and the fine powder is less likely to be selectively crushed, which in turn suppresses over-pulverization and leads to a sharper particle size distribution.

The toner production method and production apparatus preferred in the present invention are described in detail below.

First, the outline of the grinding method using the mechanical grinder used in the present invention will be explained with reference to Figures 1 and 2.

Figure 1 shows an example of a grinding system incorporating a conventional mechanical grinder, and Figure 2 shows an example of a grinding system incorporating a mechanical grinder equipped with the raw material supply mechanism of the present invention.

In Fig. 1, a schematic cross-sectional view of a typical horizontal mechanical grinding device is shown, but a vertical type may also be used. The device is made up of a rotor 103 with a number of grooves (convex and concave parts) on its outer periphery, which rotates at high speed and is attached to a central rotating shaft 107, and is located in a jacket through which water can pass, a stator 104 with a number of grooves on its inner periphery, which is arranged at regular intervals on the outer periphery of the rotor 103, a raw material inlet 101 for introducing the raw material to be processed (coarsely crushed material), a swirl chamber 102 that gives a swirling flow to the raw material and the air (cold air from a cold air generator 108) supplied into the machine, and a powder outlet 106 for discharging the powder (finely crushed material) after processing.

In the mechanical grinding machine configured as described above, when a predetermined amount of powdered raw material is fed from the constant volume feeder to the raw material inlet 101 of the mechanical grinding machine, the raw material is introduced into the grinding chamber through the vortex chamber 102. In the grinding chamber, the raw material is instantly ground by the impact generated between the rotor 103, which has multiple convex and concave portions on its surface and the stator 104, which has multiple convex and concave portions on its surface, which rotates at high speed, and the numerous ultra-high speed vortex flows that occur behind it, as well as the high frequency pressure vibrations that are generated by this. The raw material is then discharged through the powder outlet 106. The air carrying the particles passes through the grinding chamber and is discharged outside the device system through the powder outlet 106.

Examples of such mechanical grinding machines include the Innomizer (manufactured by Hosokawa Micron Corporation), Cryptoline (manufactured by Kawasaki Heavy Industries, Ltd.), Super Rotor (manufactured by Nisshin Engineering Co., Ltd.), Turbo Mill (manufactured by Turbo Kogyo Co., Ltd.), and Tornado Mill (manufactured by Nikkiso Co., Ltd.). These can be used as is or with appropriate modifications.

In the method of producing toner by pulverization, an intermediate pulverization process may be inserted between the coarse pulverization process to produce a particle size of about 2 mm and the fine pulverization process to produce the desired particle size, and the pulverization process of the present invention may be either the intermediate pulverization process or the fine pulverization process. The pulverization process of the present invention may also be connected in two or more stages in series or parallel to carry out pulverization.

In the present invention, it is important to change the method of supplying the crushed material of the crushing device described above, and supply the crushed material to the crushing area between the rotor 103 and the stator 104 by accelerating and injecting it using a powder supply mechanism (powder supply nozzle) 201, as shown in Figure 2.

The powder supply mechanism 201 is installed along the axial direction from one end side of the central rotating shaft 107 in the axial direction. This allows the fine powder components with small particle sizes among the coarsely crushed material to be transported far away without colliding with the rotor 103 and stator 104 by the effect of accelerated injection. This makes it possible to suppress the crushing of the fine powder components, leading to a sharper particle size distribution.

It is important that the grinding teeth of the rotor 103 and stator 104 are parallel to the direction of the central rotation axis 107 of the rotor 104. If the teeth have a shape in which the concaves and convexes interlock perpendicularly to the direction of the central rotation axis 107 of the rotor 103, the effect of scattering fine powder by accelerated injection and making it difficult to crush cannot be obtained. The depth of the teeth of the rotor and stator is preferably 1.0 mm or more and 2.0 mm or less. The spacing between the teeth is preferably 1.0 mm or more and 4.0 mm or less. When it is within this range, the size of the gap is sufficient to crush the coarsely crushed components to obtain the specified particle size, while making it easier to obtain the effect of scattering fine powder and preventing it from being crushed.

The speed at which the coarsely crushed material is accelerated and injected in the powder supply mechanism 201 is preferably 10 m/s or more and 50 m/s or less, and more preferably 15 m/s or more and 40 m/s or less. When the accelerated injection speed is within this range, it is easier to obtain the effect of crushing the coarsely crushed components to a predetermined particle size while scattering the finely powdered components and preventing them from being crushed.

<Method of Manufacturing Toner Particles>
Next, a procedure for producing toner particles using the production method and production apparatus of the present invention will be described.

First, in the raw material mixing process, at least the binder resin and colorant are weighed out in predetermined amounts as toner internal additives, and then mixed. If necessary, a release agent that suppresses the occurrence of hot offset during heat fixing of the toner, a dispersant that disperses the release agent, a charge control agent, etc. may be mixed. Examples of mixing devices include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, and a Nauta mixer.

The toner raw materials blended and mixed as described above are then melted and kneaded to melt the resins and disperse the colorants therein. In the melt-kneading process, for example, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. In recent years, single-screw or twin-screw extruders have become mainstream due to their advantages such as continuous production, and for example, a KTK twin-screw extruder manufactured by Kobe Steel, Ltd., a TEM twin-screw extruder manufactured by Toshiba Machine Co., Ltd., a twin-screw extruder manufactured by KCK Corporation, and a Co-Kneader manufactured by Buss Co., Ltd. are commonly used. Furthermore, the colored resin composition obtained by melt-kneading the toner raw materials is rolled with a twin roll or the like after melt-kneading, and cooled through a cooling process in which it is cooled with water or the like.

The cooled colored resin composition obtained above is then pulverized to the desired particle size in a pulverization process. In the pulverization process, the mixture is first coarsely pulverized using a crusher, hammer mill, feather mill, or the like. It is then finely pulverized using the mechanical pulverizer of the present invention. In this way, the mixture is pulverized stepwise to the desired toner particle size in the pulverization process.

(Toner raw materials)
Next, the raw materials of the toner particles containing at least the binder resin and the colorant used in the present invention will be described.

<Binder resin>
As the binder resin used in the toner used in electrophotography, a general resin can be used, and examples thereof include polyester resin, styrene-acrylic acid copolymer, polyolefin resin, vinyl resin, fluororesin, phenol resin, silicone resin, and epoxy resin. Among these, from the viewpoint of improving low-temperature fixing property, amorphous polyester resin is used, and from the viewpoint of achieving both low-temperature fixing property and hot offset resistance, it is known to use a low-molecular-weight polyester and a high-molecular-weight polyester in combination. In addition, from the viewpoint of further improving low-temperature fixing property and blocking resistance during storage, a crystalline polyester may be used as a plasticizer.

<Coloring Agent>
Colorants that can be contained in the toner include the following.

The colorant may be a known organic pigment or oil-based dye, carbon black, or a magnetic material.

Cyan colorants include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds.

Magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds.

Yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.

Black colorants include carbon black, magnetic materials, or those toned to black using the above-mentioned yellow colorants, magenta colorants, and cyan colorants.

The colorants can be used alone or in combination of two or more.

<Release Agent>
If necessary, a release agent for suppressing the occurrence of hot offset during the heat fixing of the toner may be used. Typical examples of the release agent include low molecular weight polyolefins, silicone wax, fatty acid amides, ester waxes, carnauba wax, and hydrocarbon waxes.

Next, we will explain how to measure the characteristic values related to the present invention and the examples described below.

<Calculation of accelerated injection speed>
The velocity of the accelerated injection was calculated from the following formula 1. The volumetric flow rate used was a value obtained by measuring with a flow meter.
(Velocity) = (Volumetric flow rate) / (Effective cross-sectional area of the pipe) (Equation 1)

<Method of measuring weight average particle size (D4) of toner particles>
The weight average particle size (D4) of the toner particles is measured using a precision particle size distribution measuring device by a pore electrical resistance method equipped with a 50 μm aperture tube, “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.), and the accompanying dedicated software for setting measurement conditions and analyzing measurement data, “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.), with an effective measurement channel count of 25,000, and the measurement data is analyzed and calculated.

The electrolyte solution used for the measurements is one in which special grade sodium chloride is dissolved in ion-exchanged water to give a concentration of approximately 1% by mass, for example "ISOTON II" (manufactured by Beckman Coulter).

Before performing measurements and analysis, configure the dedicated software as follows:

In the "Change Standard Measurement Method (SOM) screen" of the dedicated software, set the total count number in control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard Particle 10.0 μm" (manufactured by Beckman Coulter). Press the threshold/noise level measurement button to automatically set the threshold and noise level. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check the aperture tube flush after measurement.

In the dedicated software's "Pulse to particle size conversion setting screen," set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 1 μm or more and 30 μm or less.

The specific measurement method is as follows.
(1) Pour about 200 ml of the electrolyte solution into a 250 ml round-bottom glass beaker for use with the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, remove dirt and air bubbles from inside the aperture tube using the "aperture flush" function of the analysis software.
(2) Approximately 30 ml of the aqueous electrolyte solution is placed in a 100 ml flat-bottom glass beaker, and approximately 0.3 ml of a solution prepared by diluting "Contaminon N" (a 10% by weight aqueous solution of a neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, having a pH of 7, manufactured by Wako Pure Chemical Industries, Ltd.) three times by weight with ion-exchanged water is added as a dispersant.
(3) A predetermined amount of ion-exchanged water is placed in the water tank of an ultrasonic disperser "Ultrasonic Dispersion System Tetora 150" (manufactured by Nikkaki Bios Co., Ltd.) having two built-in oscillators with an oscillation frequency of 50 kHz and a phase shift of 180 degrees and an electrical output of 120 W, and about 2 ml of the Contaminon N is added to this water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid surface of the electrolytic solution in the beaker is maximized.
(5) In a state where the electrolyte solution in the beaker in (4) is irradiated with ultrasonic waves, about 10 mg of toner is added little by little to the electrolyte solution and dispersed. Then, ultrasonic dispersion treatment is continued for another 60 seconds. During ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted so as to be 10°C or higher and 40°C or lower.
(6) Using a pipette, the electrolyte aqueous solution (5) in which the toner is dispersed is dropped into the round-bottom beaker (1) placed in the sample stand, and the measurement concentration is adjusted to about 5%. Then, the measurement is continued until the number of particles measured reaches 50,000.
(7) The measurement data is analyzed using the dedicated software that comes with the device, and the weight-average particle size (D4) is calculated. Note that when the dedicated software is set to Graph/Volume %, the "Average diameter" on the Analysis/Volume Statistics (Arithmetic Mean) screen is the weight-average particle size (D4).

<Method of measuring number average particle size (D1) of toner particles>
In step (7) of the method for measuring the number average particle diameter (D4) of toner particles, when the dedicated software is set to Graph/Number %, the “Average diameter” on the Analysis/Number statistics (arithmetic mean) screen is the number average particle diameter (D1).

<Production Example of Polyester Resin L>
Polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane: 72.0 parts by mass (0.20 moles; 100.0 mol% based on the total number of moles of polyhydric alcohol)
・Terephthalic acid:
28.0 parts by mass (0.17 moles; 100.0 mol% based on the total number of moles of polyvalent carboxylic acids)
Tin 2-ethylhexanoate (esterification catalyst): 0.5 parts by mass The above materials were weighed and placed in a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple. The atmosphere in the flask was then replaced with nitrogen gas, and the temperature was gradually raised with stirring, and the mixture was allowed to react for 4 hours at 200°C while stirring.

The pressure in the reactor was then reduced to 8.3 kPa and maintained for 1 hour, after which it was cooled to 180°C and returned to atmospheric pressure.

・Trimellitic anhydride:
3 parts by mass (0.01 mole; 4.0 mol% based on the total number of moles of polycarboxylic acids)
tert-Butylcatechol (polymerization inhibitor): 0.1 part by mass Thereafter, the above materials were added, the pressure in the reaction tank was reduced to 8.3 kPa, and the reaction was carried out for 1 hour while maintaining the temperature at 180° C. After confirming that the softening point measured in accordance with ASTM D36-86 reached 90° C., the temperature was reduced to stop the reaction, and polyester resin L, which is a binder resin component, was obtained.

<Production Example of Polyester Resin H>
Polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane: 72.3 parts by mass (0.20 moles; 100.0 mol% based on the total number of moles of polyhydric alcohol)
・Terephthalic acid:
18.3 parts by mass (0.11 moles; 65.0 mol% based on the total number of moles of polycarboxylic acids)
Fumaric acid:
2.9 parts by mass (0.03 moles; 15.0 mol% based on the total number of moles of polyvalent carboxylic acids)
Tin 2-ethylhexanoate (esterification catalyst): 0.5 parts by mass The above materials were weighed and placed in a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple. The atmosphere in the flask was then replaced with nitrogen gas, and the temperature was gradually raised with stirring, and the mixture was allowed to react for 2 hours at 200°C while stirring.

The pressure in the reactor was then reduced to 8.3 kPa and maintained for 1 hour, after which it was cooled to 180 and returned to atmospheric pressure.

・Trimellitic anhydride:
6.5 parts by mass (0.03 moles; 20.0 mol% based on the total number of moles of polyvalent carboxylic acids)
tert-Butylcatechol (polymerization inhibitor): 0.1 part by mass Thereafter, the above materials were added, the pressure in the reaction tank was reduced to 8.3 kPa, and the reaction was carried out for 15 hours while maintaining the temperature at 160° C. After it was confirmed that the softening point measured in accordance with ASTM D36-86 reached 137° C., the temperature was reduced to stop the reaction, and a polyester resin H, which is a binder resin component, was obtained.

<Crystalline Polyester Resin>
1,6-Hexanediol:
34.5 parts by mass (0.29 moles; 100.0 mol% based on the total number of moles of polyhydric alcohol)
Dodecanedioic acid:
65.5 parts by mass (0.28 moles; 100.0 mol% based on the total number of moles of polyvalent carboxylic acids)
The above materials were weighed into a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple. After replacing the atmosphere in the flask with nitrogen gas, the temperature was gradually raised with stirring, and the reaction was carried out for 3 hours at a temperature of 140° C. with stirring.

Next, the above materials were added, the pressure in the reaction vessel was reduced to 8.3 kPa, and the reaction was carried out for 4 hours while maintaining the temperature at 200°C.

The pressure in the reaction vessel was gradually released to return to normal pressure, and then 7.0 mol % of one or more aliphatic compounds selected from the group consisting of aliphatic monocarboxylic acids and aliphatic monoalcohols was added to 100.0 mol % of the raw material monomer, and the mixture was reacted at 200°C for 2 hours under normal pressure.

Then, the pressure in the reaction vessel was reduced again to 5 kPa or less, and the reaction was carried out at 200°C for 3 hours to obtain a crystalline polyester resin.

<Production of Crushed Material for Toner>
Amorphous polyester resin L 80 parts by mass Amorphous polyester resin H 20 parts by mass Crystalline polyester resin 5 parts by mass Fischer-Tropsch wax (hydrocarbon wax, maximum endothermic peak temperature 90°C) 8 parts by mass C.I. Pigment Blue 15:3 7 parts by mass The above materials were mixed using a Henschel mixer (FM-75 type, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 20s ^-1 and a rotation time of 5 min, and then kneaded with a twin-screw kneader (PCM-30 type, manufactured by Ikegai Co., Ltd.). The barrel temperature during kneading was set so that the outlet temperature of the kneaded product was 120°C. The outlet temperature of the kneaded product was directly measured using a handheld thermometer HA-200E manufactured by Anritsu Meter Co., Ltd. The kneaded product obtained was cooled and coarsely pulverized with a pin mill to a volume average particle size of 100 μm or less to obtain a coarsely pulverized product.

<Manufacturing Apparatus 1>
The milling device was constructed by modifying a mechanical mill (Turbo Mill T250-CRS, rotor type RS, manufactured by Turbo Kogyo Co., Ltd.) and installing a supply mechanism 201 capable of supplying raw material by accelerated injection, as shown in Fig. 2. The configuration is shown in Table 1.

<Manufacturing Apparatus 2>
The mechanical grinding machine (Turbo Mill T250-CRS, rotor shape RS type, manufactured by Turbo Kogyo Co., Ltd.) was used (Figure 1). The configuration is shown in Table 1.

<Manufacturing Equipment 3>
The milling device was a modified mechanical mill (Turbo Mill T250-CRS, rotor shape RS type, manufactured by Turbo Kogyo Co., Ltd.), with the same raw material supply method as accelerated injection as in the manufacturing device 1, and with the rotor and stator having uneven teeth that mesh with each other as shown in Figure 3. The configuration is shown in Table 1.

<Production Warehouse 4>
A jet type pulverizer shown in Fig. 4 was used. The coarsely crushed material was accelerated by compressed air, passed through a nozzle 402 connected to a pulverizing chamber 401, and struck an impact plate 403, where it was pulverized. The material was then collected to obtain finely crushed material.

<Toner Production Method 1>
The device 1 was operated with a feed of coarsely crushed material of 10 kg/h, a rotor speed of 170 m/s, a gap between the rotor and stator of 1.0 mm, a cold air temperature of -10°C, and a cold air volume of 8 ^m3 /min. The conditions for accelerated injection were a nozzle diameter of 21.6 mm, a pressure of 0.5 MPa, and a flow rate of 0.5 L/min. The accelerated injection speed was 22.7 m/s.

<Production Examples of Toner Production Methods 2 to 5>
The same operation as in Toner Production Example 1 was carried out, except that in Toner Production Method 1, the device configuration and the accelerated jetting speed in feeding the coarsely crushed material were changed as shown in Table 2.

<Production Example of Toner Production Method 6>
Using the apparatus 2, the raw materials were supplied not by a jet system but by a system of supplying the raw materials on the cold air, and thus the pulverization was carried out.

<Production Example of Toner Production Method 7>
The milling was carried out using the apparatus 3. The rotor and stator have a large convex shape. The raw material was accelerated and sprayed at a speed of 8.8 m/s.

<Production Example of Toner Production Method 8>
The grinding was carried out using the apparatus 4. The accelerated ejection speed of the raw material was 8.8 m/s.

Example 1
The pulverizer was operated in the same manner as in toner production method 1, and the particle size distributions D4 and D1 of the resulting finely pulverized product were measured, and evaluation was made of D4/D1 and D4.

[D4/D1]
The particle size distribution was evaluated. The smaller the value, the sharper the distribution. The evaluation results are shown in Table 3.

(Evaluation Criteria)
A: D4/D1 is less than 1.35 (very good)
B: D4/D1 is 1.35 or more and less than 1.40 (good)
C: D4/D1 is 1.40 or more and less than 1.45 (this is not a problem in the present invention)
D: D4/D11.50 or more (not acceptable in the present invention)

[D4]
A grinding device that does not provide the required grinding performance is not acceptable as an invention. Therefore, the center particle size was also measured and evaluated. The evaluation results are shown in Table 3.

(Evaluation Criteria)
A: D4 is less than 4.70 (very good)
B: D4 is 4.70 or more and less than 4.80 (good)
C: D4 is 4.80 or more and less than 4.90 (this level is not problematic in the present invention)
D: D4 is 5.00 or more (not acceptable in the present invention)

<Examples 2 to 5 and Comparative Examples 1 to 3>
Except for changing the production method, evaluation was performed in the same manner as in Example 1. The evaluation results are shown in Table 3.

In Comparative Example 1, the coarsely crushed material was supplied in the normal manner without accelerated crushing. It is presumed that the accelerated injection eliminated the effect of suppressing the crushing of fine powder, resulting in a poor evaluation of D4/D1, which indicates the particle size distribution.

In Comparative Example 2, the grinding teeth are interlocking teeth. The accelerated and injected coarsely crushed material collides directly with the grinding teeth, which is thought to result in an increase in small particles and a poor evaluation of D4/D1, which indicates the particle size distribution.

Comparative Example 3 is an example of pulverization using a jet mill. In a jet mill, the coarsely pulverized material is pulverized by colliding it with the collision plate (403) in Figure 4, which increases the number of small particles. It is presumed that this resulted in a poor evaluation of D4/D1, which indicates the particle size distribution.

101: Supply port, 102: volute (volute tube), 103: rotor, 104: stator, 105: rear chamber, 106: Discharge port, 107: Rotating shaft, 108: Cold air generator, 109: Cold water supply port, 110: Cold water discharge port, 201: Powder supply mechanism (powder supply nozzle), 401: Grinding chamber, 402: Nozzle, 403: Collision plate

Claims (3)

A toner manufacturing method comprising a step of finely pulverizing a material to be pulverized by a pulverizing means,
The crushing means is
A powder supply mechanism for supplying the material to be pulverized;
a stator having a plurality of protrusions and recesses on an inner circumferential surface;
a rotor attached to a central rotating shaft and having a plurality of protrusions and recesses on an outer circumferential surface;
A powder discharge port for discharging the finely pulverized material;
having
the stator contains the rotor, and the rotor is disposed so that a surface of the stator and a surface of the rotor face each other with a predetermined gap therebetween;
The recesses and protrusions on the inner peripheral surface of the stator and the outer peripheral surface of the rotor are formed along the axial direction of the central rotating shaft,
the concaves and convexes on the inner peripheral surface of the stator and the concaves and convexes on the outer peripheral surface of the rotor are not interdigitated with each other in a direction perpendicular to the central rotation axis direction,
The material to be pulverized is pulverized in a pulverization region formed by a gap between the stator and the rotor by the rotation of the rotor,
The material to be pulverized is accelerated and sprayed from one end of the central rotating shaft in the axial direction by a powder supply nozzle, which is the powder supply mechanism, and supplied to the pulverizing region;
The finely pulverized material is discharged from the powder discharge port provided on the other end side of the central rotating shaft in the axial direction.
A method for producing a toner comprising the steps of: The method for producing toner according to claim 1, wherein the speed of the crushed material when accelerated and sprayed by the powder supply mechanism is 10 m/s or more and 50 m/s or less. A toner manufacturing apparatus having a step of finely pulverizing a material to be pulverized by a pulverizing means,
The crushing means is
A powder supply mechanism for supplying the material to be pulverized;
a stator having a plurality of protrusions and recesses on an inner circumferential surface;
a rotor attached to a central rotating shaft and having a plurality of protrusions and recesses on an outer circumferential surface;
A powder discharge port for discharging the finely pulverized material;
having
the stator contains the rotor, and the rotor is disposed so that a surface of the stator and a surface of the rotor face each other with a predetermined gap therebetween;
The recesses and protrusions on the inner peripheral surface of the stator and the outer peripheral surface of the rotor are formed along the axial direction of the central rotating shaft,
the concaves and convexes on the inner peripheral surface of the stator and the concaves and convexes on the outer peripheral surface of the rotor are not interdigitated with each other in a direction perpendicular to the central rotation axis direction,
The material to be pulverized is pulverized in a pulverization region formed by a gap between the stator and the rotor by the rotation of the rotor,
The powder supply nozzle, which is the powder supply mechanism, is a means for accelerating and spraying the material to be pulverized from one end side of the axial direction of the central rotation shaft along the axial direction to supply the material to the pulverization region,
The finely pulverized material is discharged from the powder discharge port provided on the other end side of the central rotating shaft in the axial direction.
A toner manufacturing apparatus comprising:

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