Toner manufacturing method and manufacturing device

Abstract

To provide a method for manufacturing a toner having sharp particle size distribution.SOLUTION: A method for manufacturing a toner has a step of pulverizing a material to be pulverized with pulverization means. The pulverization means has a powder supply mechanism 201 that supplies the material to be pulverized, a stator 104 that has a plurality of convex parts and concave parts on an inner peripheral surface, a rotor 103 that is attached to a central rotation shaft and has a plurality of convex parts and concave parts on an outer peripheral surface, and a powder discharge port 106 that discharges the material to be pulverized. The rotor is arranged so that a surface of the stator and a surface of the rotor face each other. The concave parts and convex parts present on the inner peripheral surface of the stator and the outer peripheral surface of the rotor are formed along an axial direction of the central rotation shaft. The material to be pulverized is pulverized in a gap between the stator and the rotor. The material to be pulverized is accelerated and injected by the powder supply mechanism from one end side in the axial direction of the central rotation shaft along the axial direction and supplied to a pulverization area. The pulverized material to be pulverized is discharged from the powder discharge port provided on the other end side in the axial direction of the central rotation shaft.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method and an apparatus for producing a toner used in an electrophotographic system, an electrostatic recording system, an electrostatic printing system, and a toner jet system. [Background technology]

[0002] 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. However, mechanical pulverizers (Patent Documents 1 and 2, etc.), which are often used as pulverizers, have the disadvantage that it is difficult to sharpen the particle size distribution compared to toners manufactured by polymerization methods, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-21768 A [Patent Document 2] JP 2011-237816 A Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a method and apparatus for producing toner which solves the above-mentioned problems associated with mechanical grinding devices used as grinding devices in toner production and which produces a toner with a sharp particle size distribution. [Means for solving the problem]

[0005] 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 law of nature, 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 fed from one end of the central rotating shaft in the axial direction to the powder supply mechanism. Powder supply nozzle and is accelerated and injected into the grinding area; The finely pulverized material is discharged from the powder discharge port provided on the other end side of the central rotation 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 law of nature, 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 mechanism Powder supply nozzle is a means for accelerating and ejecting the material to be pulverized from one end side of the central rotating shaft in the axial direction to supply it to the pulverizing region, The finely pulverized material is discharged from the powder discharge port provided on the other end side of the central rotation shaft in the axial direction. The present invention relates to a toner manufacturing apparatus characterized in that Effect of the Invention

[0006] According to the present invention, it is possible to provide a method and an apparatus for producing a toner with a sharp particle size distribution. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram of a conventional mechanical grinding device. [Diagram 2] FIG. 2 is a diagram of a mechanical grinding device used in the present invention. [Diagram 3] FIG. 1 is a diagram of an interlocking tooth grinding device. [Figure 4] FIG. 1 is a diagram of a jet milling device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] 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 rotating shaft. However, with this method, all particle sizes of the coarsely ground material were pulverized, which tended to result in over-pulverization, 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 still room for improvement in the area of ​​demand for a sharper particle size distribution in the grinding process.

[0009] As a result of further investigations by the inventors to improve this point, they succeeded in achieving a sharp particle size distribution during grinding by using a grinding technique in which coarsely crushed material is accelerated and sprayed by a powder supply mechanism along the axial direction from one end side of the central rotating shaft in the axial direction to a processing section (grinding area) formed by opposing stators and rotors in a mechanical grinder.

[0010] 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 assume it to be as follows.

[0011] In the mechanical grinding machine of the present invention, the crushed material is accelerated and injected 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 crushed material with the rotor and stator. In other words, fine powder components of the crushed material with finer particle sizes are more susceptible to the effects of accelerated injection and are carried farther. As a result, it is presumed that the collisions of the fine powder with the rotor and stator are reduced, making it difficult for the fine powder to be selectively crushed, which results in suppression of over-pulverization and sharpening of the particle size distribution.

[0012] A toner production method and production apparatus preferred in the present invention will be described in detail below.

[0013] First, the outline of the pulverization method using the mechanical pulverizer used in the present invention will be described with reference to Figs.

[0014] FIG. 1 shows an example of a grinding system incorporating a conventional mechanical grinder, and FIG. 2 shows an example of a grinding system incorporating a mechanical grinder equipped with a raw material supply mechanism of the present invention.

[0015] 1 shows a schematic cross-sectional view of a typical horizontal mechanical grinding device, but it may be a vertical type. The device is equipped with a cooling water supply port 109, a cooling water discharge port 110, and a rotor 103 with many grooves (convex and concave parts) on its outer circumferential surface, which rotates at high speed and is made of a rotor attached to a central rotating shaft 107, in a jacket through which water can pass, a stator 104 with many grooves on its inner circumferential surface, which is arranged at regular intervals on the outer circumferential surface 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 device, and a powder outlet 106 for discharging the powder (finely crushed material) after processing.

[0016] In the mechanical pulverizer constructed 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 pulverizer, the raw material is introduced into the pulverization chamber through the volute chamber 102. In the pulverization chamber, the raw material is instantaneously pulverized 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 generated behind the rotor and the high frequency pressure vibrations generated by the impact. The raw material is then discharged through the powder outlet 106. The air carrying the particles passes through the pulverization chamber and is discharged outside the device system through the powder outlet 106.

[0017] Examples of such mechanical grinding machines include 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.), Tornado Mill (manufactured by Nikkiso Co., Ltd.), etc. These can be used as is or after appropriate modification.

[0018] In the toner manufacturing method using the pulverization method, an intermediate pulverization step may be inserted between a coarse pulverization step for reducing the particle size to about 2 mm and a fine pulverization step for reducing the particle size to a desired particle size, and the pulverization process of the present invention may be either the intermediate pulverization step or the fine pulverization step. The pulverization process of the present invention may also be connected in two or more stages in series or parallel.

[0019] In the present invention, it is important to change the method of supplying coarse crushed material to the crushing device described above, and supply the coarse crushed material by accelerating and spraying it into the crushing area between the rotor 103 and the stator 104 using a powder supply mechanism (powder supply nozzle) 201, as shown in Figure 2.

[0020] The powder supply mechanism 201 is installed along the axial direction from one end side of the axial direction of the central rotating shaft 107. This allows the fine powder components with small particle sizes among the coarsely crushed materials to be carried far away by the effect of accelerated injection without colliding with the rotor 103 and stator 104. This makes it possible to suppress the crushing of the fine powder components, leading to a sharper particle size distribution.

[0021] It is important that the grinding teeth of the rotor 103 and the 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 the fine powder by accelerated injection and making it difficult to crush cannot be obtained. The depth of the teeth of the rotor and the 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 can easily obtain the effect of scattering the fine powder and preventing it from being crushed, while pulverizing the coarsely crushed components to obtain the specified particle size.

[0022] 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 easy to obtain the effect of scattering the finely powdered components without crushing them, while crushing the coarsely crushed components to obtain a predetermined particle size.

[0023] <Toner particle manufacturing method> Next, a procedure for producing toner particles using the production method and production apparatus of the present invention will be described.

[0024] 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 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, a Nauta mixer, etc.

[0025] Furthermore, the toner raw materials blended and mixed as described above are melt-kneaded to melt the resins and disperse the colorant therein. In the melt-kneading step, for example, a batch-type 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 two-roller or the like after melt-kneading, and cooled through a cooling step in which it is cooled with water or the like.

[0026] The cooled colored resin composition obtained above is then pulverized to a desired particle size in a pulverization step. In the pulverization step, the colored resin composition is first coarsely pulverized using a crusher, a hammer mill, a feather mill, or the like. Then, the colored resin composition is finely pulverized using a mechanical pulverizer according to the present invention. In this manner, the colored resin composition is pulverized stepwise to a predetermined toner particle size.

[0027] (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.

[0028] <Binding 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 low-molecular-weight polyester and high-molecular-weight polyester in combination. In addition, from the viewpoint of further improving low-temperature fixing property and blocking resistance during storage, crystalline polyester may be used as a plasticizer.

[0029] <Coloring agent> Colorants that can be contained in the toner include the following.

[0030] The colorant may be a known organic pigment or oil-based dye, carbon black, or a magnetic material.

[0031] Examples of cyan colorants include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds.

[0032] Examples of 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.

[0033] Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.

[0034] Examples of black colorants include carbon black, magnetic materials, and those toned to black using the above-mentioned yellow colorants, magenta colorants, and cyan colorants.

[0035] The colorants may be used alone or in combination of two or more.

[0036] <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.

[0037] Next, methods for measuring characteristic values ​​according to the present invention and the examples described below will be described.

[0038] <Calculation of accelerated jet speed> The acceleration injection speed was calculated from the following formula 1. The volumetric flow rate was measured using a flow meter. (Velocity) = (Volumetric flow rate) / (Effective cross-sectional area of ​​the pipe) (Equation 1)

[0039] <Method of measuring weight average particle size (D4) of toner particles> The weight-average particle diameter (D4) of the toner particles is measured with an effective measurement channel count of 25,000 channels using a precision particle size distribution measuring device using the narrow hole electrical resistance method, "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter, Inc.), equipped with a 50 μm aperture tube, and the accompanying dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.), for setting measurement conditions and analyzing measurement data, and is calculated by analyzing the measurement data.

[0040] The electrolyte solution used for the measurement is prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of approximately 1% by mass, for example, "ISOTON II" (manufactured by Beckman Coulter).

[0041] Before carrying out the measurements and analyses, the dedicated software is set up as follows.

[0042] In the "Change Standard Measurement Method (SOM) screen" of the dedicated software, set the total count number in the 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" (Beckman Coulter). Press the threshold / noise level measurement button to automatically set the threshold and noise level. In addition, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check the aperture tube flush after measurement.

[0043] In the "Pulse to particle size conversion setting screen" of the dedicated software, 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.

[0044] The specific measurement method is as follows. (1) Pour about 200 ml of the electrolyte solution into a 250 ml round-bottom glass beaker made exclusively for the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, use the "aperture flush" function of the analysis software to remove dirt and air bubbles from inside the aperture tube. (2) Approximately 30 ml of the above-mentioned 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, with 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 specified amount of ion-exchanged water is placed in the water tank of an ultrasonic disperser "Ultrasonic Dispension System Tetora150" (manufactured by Nikkaki Bios Co., Ltd.) that has two oscillators with an oscillation frequency of 50 kHz built in with a phase shift of 180 degrees and an electrical output of 120 W, and approximately 2 ml of the Conaminon N is added to this water tank. (4) The beaker (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 electrolyte solution in the beaker is maximized. (5) While 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 to be 10°C or higher and 40°C or lower. (6) Using a pipette, add the electrolyte solution (5) in which the toner is dispersed to the round-bottom beaker (1) placed in the sample stand, and adjust the measurement concentration to about 5%. Then, measurements are 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).

[0045] <Method of measuring number average particle size (D1) of toner particles> In step (7) of the measurement method for the number-average particle diameter (D4) of toner particles, when you select Graph / Number % in the dedicated software, the “Average diameter” on the Analysis / Number statistics (arithmetic mean) screen is the number-average particle diameter (D1). EXAMPLES

[0046] <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 polycarboxylic 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. Next, the atmosphere in the flask was replaced with nitrogen gas, and the temperature was gradually raised with stirring, and the reaction was carried out for 4 hours at a temperature of 200°C with stirring.

[0047] The pressure inside the reaction vessel was then reduced to 8.3 kPa and maintained for 1 hour, after which the vessel was cooled to 180° C. and returned to atmospheric pressure.

[0048] 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 parts 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 it was confirmed that the softening point measured in accordance with ASTM D36-86 reached 90°C, the temperature was reduced to stop the reaction, thereby obtaining polyester resin L, which is a binder resin component.

[0049] <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 polycarboxylic 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. Next, the atmosphere in the flask was replaced with nitrogen gas, and the temperature was gradually raised with stirring, and the reaction was carried out for 2 hours at a temperature of 200°C with stirring.

[0050] 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.

[0051] Trimellitic anhydride: 6.5 parts by mass (0.03 moles; 20.0 mol% based on the total number of moles of polycarboxylic acids) tert-Butylcatechol (polymerization inhibitor): 0.1 parts 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 polyester resin H, which is a binder resin component, was obtained.

[0052] <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 polycarboxylic acids) Tin 2-ethylhexanoate: 0.5 parts by weight 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. 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.

[0053] Next, the above materials were added, the pressure in the reaction vessel was reduced to 8.3 kPa, and the temperature was maintained at 200° C. while the reaction was carried out for 4 hours.

[0054] Furthermore, the pressure in the reaction tank was gradually released to return to normal pressure, and then one or more aliphatic compounds selected from the group consisting of aliphatic monocarboxylic acids and aliphatic monoalcohols were added in an amount of 7.0 mol% relative to 100.0 mol% of the raw material monomer, and the mixture was reacted at 200°C for 2 hours under normal pressure.

[0055] Thereafter, the pressure inside the reaction vessel was reduced again to 5 kPa or less, and the mixture was reacted at 200° C. for 3 hours to obtain a crystalline polyester resin.

[0056] <Production of Crushed Material for Toner> Amorphous polyester resin L 80 parts by weight Amorphous polyester resin H 20 parts by weight Crystalline polyester resin 5 parts by weight Fischer-Tropsch wax (hydrocarbon wax, maximum endothermic peak temperature 90°C) 8 parts by mass CI Pigment Blue 15:3 7 parts by weight The above materials were mixed in a Henschel mixer (FM-75, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 20 s. -1 After mixing for 5 minutes at 100°C, the mixture was kneaded in a twin-screw kneader (PCM-30, manufactured by Ikegai Corporation). 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 handy type thermometer HA-200E manufactured by Anritsu Keiki Co., Ltd. The kneaded product obtained was cooled and coarsely crushed in a pin mill to a volume average particle size of 100 μm or less to obtain a coarsely crushed product.

[0057] <Manufacturing equipment 1> The milling equipment was configured by modifying a mechanical mill (Turbo Mill T250-CRS, rotor shape RS type, manufactured by Turbo Kogyo Co., Ltd.) and installing a supply mechanism 201 capable of supplying raw material by accelerated injection, as shown in Figure 2. The configuration is shown in Table 1.

[0058] <Manufacturing equipment 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.

[0059] <Manufacturing equipment 3> The milling equipment 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 the accelerated injection as in the manufacturing equipment 1, and with the rotor and stator teeth as shown in Figure 3 that mesh with each other with unevenness. The configuration is shown in Table 1.

[0060] <Production Warehouse 4> A jet-type pulverizer shown in Fig. 4 was used. The coarsely crushed material is accelerated by compressed air, passes through a nozzle 402 connected to a pulverizing chamber 401, hits a collision plate 403, and is pulverized. The material is then collected to obtain finely crushed material.

[0061] [Table 1]

[0062] <Toner manufacturing method 1> In the configuration of device 1, the feed of coarsely crushed material is 10 kg / h, the rotor speed is 170 m / s, the gap between the rotor and the stator is 1.0 mm, the cold air temperature is -10°C, and the cold air volume is 8 m 3 The conditions for the accelerated injection were a nozzle diameter of 21.6 mm, pressure of 0.5 MPa, and flow rate of 0.5 L / min. The accelerated injection speed was 22.7 m / s.

[0063] <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.

[0064] <Production Example of Toner Production Method 6> Using the device 2, the raw materials were supplied not by jet but by cold air to carry them through the grinding process.

[0065] <Production Example of Toner Production Method 7> The milling was carried out using Apparatus 3. The rotor and stator are characterized by large convex shapes. The raw material was accelerated and sprayed at a speed of 8.8 m / s.

[0066] <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.

[0067] [Table 2]

[0068] <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 evaluations were made of D4 / D1 and D4.

[0069] [D4 / D1] The particle size distribution was evaluated. The smaller the value, the sharper the distribution. The evaluation results are shown in Table 3.

[0070] (Evaluation Criteria) A: D4 / D1 is less than 1.35 (excellent) 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 level is not problematic in the present invention) D: D4 / D11.50 or more (not acceptable in this invention)

[0071] [D4] A grinding device that does not provide the required grinding performance cannot be considered an invention. Therefore, the center particle size was also measured and evaluated. The evaluation results are shown in Table 3.

[0072] (Evaluation Criteria) A:D4 below 4.70 (Excellent) 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 this invention)

[0073] <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.

[0074] [Table 3]

[0075] In Comparative Example 1, the coarsely crushed material was fed in a normal manner without accelerated pulverization. It is presumed that the evaluation of D4 / D1, which indicates the particle size distribution, was poor because accelerated injection eliminates the effect of suppressing the pulverization of fine powder.

[0076] In Comparative Example 2, the grinding teeth are meshing teeth. The accelerated and jetted coarsely crushed material collides directly with the grinding teeth, which is thought to be the reason for the increase in small particles and the poor evaluation of D4 / D1, which indicates the particle size distribution.

[0077] 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 Fig. 4, which increases the number of small particles. This is presumably why the evaluation of D4 / D1, which indicates the particle size distribution, was poor. [Explanation of symbols]

[0078] 101: supply port, 102: volute (volute tube), 103: rotor, 104: stator, 105: rear chamber, 106: exhaust port, 107: rotating shaft, 108: cold air generator, 109: cold water supply port, 110: cold water exhaust port, 201: powder supply mechanism (powder supply nozzle), 401: grinding chamber, 402: nozzle, 403: collision plate

Claims

1. 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 rotation 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 is 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 rotation shaft in the axial direction. A method for producing a toner comprising the steps of:

2. 2. The method for producing toner according to claim 1, wherein the speed of the crushed material when accelerated and jetted by the powder supply mechanism is 10 m / s or more and 50 m / s or less.

3. 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 rotation 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 rotation shaft in the axial direction. A toner manufacturing apparatus comprising:

Images