JP2021196437A - Method for manufacturing toner - Google Patents

Abstract

To provide a pulverization method with which toner particles obtained have a fine particle diameter.SOLUTION: A method for manufacturing toner particles has a step of pulverizing a material to be pulverized containing a binder resin and a colorant with pulverization means. The pulverization means has a stator 104 that has a plurality of convex parts and concave parts on an inner peripheral surface, and a rotor 103 that is attached to a central rotation shaft 107 and has a plurality of convex parts and concave parts on an outer peripheral surface. The stator includes the rotor, and the rotor is arranged so that a surface of the stator and a surface of the rotor face each other with a predetermined gap therebetween. The convex parts and concave parts on the inner peripheral surface and the convex parts and concave parts on the outer peripheral surface are formed along an axial direction of the central rotation shaft. The material to be pulverized is accelerated and injected by a powder supply mechanism and supplied from a supply port 201 to directly collide with the outer peripheral surface of the rotor, and pulverization is performed by the rotation of the rotor in a pulverization area formed by the gap between the stator and the rotor.SELECTED DRAWING: Figure 2

Description

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

In recent years, electrophotographic full-color copiers have become widespread and have begun to be applied to the printing market. In the printing market, it is required to obtain high-quality printed matter at high speed while supporting a wide range of media (paper types).
As a specific measure for improving image quality, a toner having a small toner particle diameter and a uniform particle size distribution that does not contain coarse particles and fine particles is required in order to improve dot reproducibility.
The following method is one of the dry toner manufacturing methods. First, a binder resin for fixing to the material to be transferred, various colorants for giving a color as a toner, and, if necessary, additives such as a mold release agent and a fluidity-imparting agent are added for dry mixing. conduct. Next, after melt-kneading with a general-purpose kneader such as a roll mill or extruder and cooling and solidifying, the kneaded material is pulverized by various pulverizers, and the obtained coarse pulverized material is introduced into various wind power classifiers for classification. As a result, a graded product having a particle size required as a toner is obtained. Further, if necessary, a fluidizing agent, a lubricant, or the like is externally added, and the toner is dry-mixed to obtain a toner to be used for image formation.
As an example of an apparatus for miniaturizing a kneaded product, there is a mechanical crusher in which crushing is performed between a rotor rotating at high speed and a stator arranged around the rotor (Patent Document 1). In this method, the object to be crushed moves at high speed between the rotor and the stator by the rotor rotating at high speed, and is finely crushed by the collision generated at that time.
By controlling the rotation speed of the rotor, it is possible to obtain a toner having a desired particle size, but the rotation speed of the rotor in the crusher is limited, and therefore the reachable toner particle size is also limited. There is a limit.
As a toner pulverizer different from the mechanical crusher, there is an airflow crusher that uses high pressure air to move the object to be crushed at high speed and crushes the object to be crushed by the collision energy generated at that time (Patent Document 2). ). In this method, it is possible to apply higher collision energy to the object to be crushed, but it is known that the particle size distribution of the obtained toner fine particles is broader than that of the mechanical crusher.

Japanese Unexamined Patent Publication No. 2011-237816 Japanese Unexamined Patent Publication No. 2006-051496

As described above, in order to improve the image quality of printed matter, there is a demand for a toner having a small toner particle size and a uniform particle size distribution that does not contain coarse particles and fine particles. The sharper the particle size distribution in the toner miniaturization step, the smaller the amount of fine powder and coarse powder to be removed in the subsequent classification step, which is preferable from the viewpoint of productivity. An object of the present invention is to provide a method for producing toner particles having a small particle size and a sharp particle size distribution in a toner miniaturization step.

As a result of studies in order to solve the above-mentioned problems of the prior art, the present inventors have found that the method of supplying raw materials in the mechanical crusher is related to the particle size and particle size distribution of the obtained toner particles. The present invention has been reached.
That is, the present invention is a method for producing a toner, which comprises a step of finely pulverizing an object to be pulverized containing a binder resin and a colorant by a pulverizing means.
The crushing means is
A powder supply mechanism that supplies the object to be crushed,
A stator having a plurality of protrusions and recesses on the inner peripheral surface,
A rotor attached to the central rotation axis and having a plurality of protrusions and recesses on the outer peripheral surface,
A powder discharge port that discharges finely pulverized material and
Have,
The stator contains the rotor, and the rotor is arranged so that the surface of the stator and the surface of the rotor face each other with a predetermined gap.
The protrusions and recesses existing 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 axis.
The object to be crushed is acceleratedly jetted by the powder supply mechanism, supplied from the supply port so as to directly collide with the outer peripheral surface of the rotor, and crushed formed in the gap between the stator and the rotor. In the region, the rotation of the rotor causes fine grinding.
When the rotor is divided into four equal parts along the central rotation axis and each of the four equal parts is divided into first to fourth regions along the flow of the object to be crushed.
(I) The position where the object to be crushed is acceleratedly jetted by the powder supply mechanism and collides with the rotor is the first region.
(Ii) The powder discharge port is provided in the region of the stator facing the fourth region.
The accelerated air wind speed when the object to be crushed is acceleratedly injected and supplied is 10 m / sec or more and 50 m / sec or less when passing through the supply port.
The present invention relates to a toner manufacturing method.

INDUSTRIAL APPLICABILITY According to the present invention, a toner having a small particle size can be provided while maintaining high productivity.

It is a figure of a general crushing apparatus. It is a figure of the crushing apparatus used in this invention. It is a figure explaining the raw material supply position in the crushing apparatus used in this invention. It is a figure explaining the uneven shape of a stator and a rotor. It is a figure of the crushing device of a meshing type tooth.

The present invention has a feature of a raw material supply method in which an object to be crushed is acceleratedly injected into a crushing processing chamber by using high-pressure air and directly collides with a rotor rotating at high speed, as compared with a conventional general mechanical crushing device. An outline of a mechanical crusher for carrying out the present invention will be described.

-Device FIG. 1 shows a schematic cross-sectional view of a conventional general mechanical crushing device. The illustrated figure is a horizontal device, but it may be a vertical device. The supply port 101 for supplying the object to be crushed and cold air, the rotor 103 having a large number of irregularities on the outer peripheral surface attached to the central rotating shaft 107, and the rotor 103 are arranged on the outer periphery of the rotor 103 at regular intervals. A stator 104 having a large number of irregularities on the peripheral surface, a cold water supply port 109 for circulating cooling water around the outer periphery of the stator, a cold water discharge port 110, and discharged powder (finely pulverized material) and cold air after treatment. It is composed of a discharge port 106 for the purpose.

In the mechanical crusher configured as described above, when a predetermined amount of powder raw material is charged into the supply port 101, the raw material is introduced into the crushing processing chamber via the front chamber 102. The impact generated between the rotor 103 having a large number of irregularities on the surface rotating at high speed in the pulverization processing chamber and the stator 104 having a large number of irregularities on the surface, and a large number of ultrahigh-speed eddies generated behind the rotor 103, and It is instantaneously crushed by the high-frequency pressure vibration generated by this. After that, it is discharged through the discharge port 106. The air carrying the particles passes through the pulverization processing chamber and is discharged from the discharge port 106. In order to collect the powder after the treatment, there is a means for separating the powder in the air flow by using a cyclone connected from the discharge port 106 by using a pipe or the like.

Such mechanical crushers include Inomizer (manufactured by Hosokawa Micron), Cryptoline (manufactured by Kawasaki Heavy Industries), Super Rotor (manufactured by Nisshin Engineering Co., Ltd.), Turbo Mill (manufactured by Nikkiso Co., Ltd.), and Tornado Mill (manufactured by Nikkiso Co., Ltd.). ) And so on. These can be used as they are or modified as appropriate.

Carbon steel such as S45C and chrome molybdenum steel such as SCM material are often used as the base material of the rotor and stator in the mechanical crusher. By coating the surface of these base materials with a chrome alloy and then applying a mechanical surface treatment, the surface hardness and wear resistance of the crushed surface are increased, and a long-life rotor and stator can be obtained. Long run is possible.

In particular, the coating on the surface of the base material of the chromium alloy containing chromium carbide makes it possible to finish the surface uniformly and smoothly by the plating treatment, reduce the coefficient of friction, and improve the wear resistance. After the plating treatment, a polishing treatment such as buffing or a blasting treatment such as shot blasting may be performed in order to adjust the surface roughness of the rotor and the stator.

In the present invention, the method of charging the object to be crushed is changed, and as shown on the right side of FIG. 2, the raw material is directly supplied from the raw material supply port 201 to the rotor 103 rotating at high speed using compressed air. At this time, the object to be crushed is accelerated and jetted, directly collides with the outer periphery of the rotor 103, and is crushed.

The left side of FIG. 2 shows a schematic cross-sectional view on the DD'plane in the right side of FIG. A plurality of protrusions and recesses existing on the surface of the rotor and the stator are formed along the axial direction of the central rotation axis of the rotor. In the present invention, fine pulverization is performed in the pulverized region formed by the gap between the stator and the rotor, but the object to be pulverized may be supplied so as to directly collide with the outer peripheral surface of the rotor from the supply port. is important. It is believed that this makes it possible to impart higher collision energy to the object to be crushed.

The air wind speed at the time of accelerated injection of compressed air also greatly affects the particle size of the toner particles. It is necessary that the speed of the air wind speed is 10 m / sec or more and 50 m / sec or less when passing through the supply port. When the air wind speed is lower than 10 m / sec, the effect of reducing the particle size of the toner particles cannot be obtained. Further, when the air wind speed exceeds 50 m / sec, the collision energy is excessively applied, and the particle size distribution of the toner particles becomes broad due to the influence of over-grinding.

FIG. 4 is a schematic view of the uneven shape existing in the rotor and the stator. The distance Db between the protrusions of the rotor and the stator is preferably 0.8 mm or more and 1.4 mm or less, and more preferably 0.8 mm or more and 1.2 mm or less. Further, it is desirable that the distance Da between the uneven portions of the rotor and the stator is 1.0 mm or more and 1.5 mm or less. When Da and Db are in this range, the rotor rotates at high speed to generate a high-speed vortex flow with the stator. As a result, the object to be pulverized can be further pulverized by efficiently repeating collisions with the rotor and the stator. Further, in the crushing treatment chamber after the collision, when the object to be crushed becomes finer to a certain particle size, it is quickly discharged from the raw material discharge port due to the influence of the air flow in the treatment chamber. This makes it possible to suppress the broadening of the particle size distribution due to over-grinding.

In order to enhance the effect of the present invention, the angle at which the object to be crushed is introduced by accelerated injection is also important. The object to be crushed is supplied so as to face the rotation direction of the rotor, and on the plane perpendicular to the rotation axis of the rotor, the crushed object introduction direction in the left figure in FIG. 2 and the tangential direction at the raw material introduction port are The angle θ formed is preferably 20 ° or more and 80 ° or less, and more preferably 30 ° or more and 70 ° or less. The smaller the value of θ, the higher the relative speed at the time of collision between the object to be ground and the rotor. However, when the collision speed exceeds a certain value, the object to be crushed tends to be over-crushed, and the particle size distribution of the resulting toner particles becomes broad. Further, when θ is large, the relative speed between the object to be crushed and the rotor does not increase, and therefore toner particles having a desired particle size cannot be obtained. For the above reasons, θ is preferably in the above range.

Similar to the angle of the raw material supply port, the raw material supply position also affects the particle size of the obtained toner particles. That is, when the rotor is divided into four equal parts along the central rotation axis and each of the four equal parts is divided into first to fourth regions along the flow of the material to be crushed, (i) the crushed material. The position where the object is acceleratedly jetted by the powder supply mechanism and collides with the rotor is the first region, and (ii) the powder discharge port is provided in the region of the stator facing the fourth region. It is necessary to be. If this aspect is not satisfied, toner particles having a desired particle size cannot be obtained without sufficient pulverization in the pulverization processing chamber after the collision with the air flow.

FIG. 3 specifically describes the above aspect, and the ratio Lj / Lr of the distance Lj from the end of the rotor on the supply port 101 side to the raw material supply port 201 with respect to the total length Lr of the rotor in FIG. Must be 0 or more and 0.25 or less, preferably 0 or more and 0.15 or less.

(Toner manufacturing procedure)
Next, a procedure for manufacturing toner by the manufacturing method and manufacturing apparatus of the present invention will be described.

First, in the raw material mixing step, at least a binder resin and a colorant are weighed and mixed in a predetermined amount as a toner inner filler, and then mixed. If necessary, a mold release agent that suppresses the generation of hot offset when the toner is heated and fixed, a dispersant that disperses the mold release agent, a charge control agent, and the like may be mixed. Examples of the mixing device include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauter mixer, and the like.

Further, the toner raw materials blended and mixed as described above are melt-kneaded to melt the resins and disperse the colorants and the like in the resins. In the melt-kneading step, for example, a batch type kneader such as a pressure kneader or a Bambary mixer, or a continuous type kneader can be used. In recent years, single-screw or twin-screw extruders have become the mainstream because of their superiority such as continuous production. For example, KTK type twin-screw extruder manufactured by Kobe Steel Co., Ltd. and TEM type twin-screw extruder manufactured by Toshiba Machine Co., Ltd. , Kay-Cee twin-screw extruder, Buss co-kneader, etc. are generally used. Further, the colored resin composition obtained by melt-kneading the toner raw material is melt-kneaded, rolled by two rolls or the like, and cooled through a cooling step of cooling by water cooling or the like.

The cooled product of the colored resin composition obtained above is then pulverized to a desired particle size in the pulverization step. In the crushing step, first, coarse crushing is performed with a crusher, a hammer mill, a feather mill or the like. Further, it is finely pulverized by the mechanical pulverizer according to the present invention. In the pulverization step, the toner is pulverized step by step to a predetermined toner particle size.

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

<Bundling resin>
As the binder resin used for the toner used for electrophotographic, a general resin can be used, and polyester resin, styrene-acrylic acid copolymer, polyolefin resin, vinyl resin, fluororesin, phenol resin, etc. Examples thereof include silicone resin and epoxy resin. Among these, amorphous polyester resin is used from the viewpoint of improving low temperature fixability, and it is known that low molecular weight polyester and high molecular weight polyester are used in combination from the viewpoint of achieving both low temperature fixability and hot offset resistance. ing. In addition, crystalline polyester may be used as a plasticizer from the viewpoint of further improving low temperature fixability and blocking resistance during storage.

<Colorant>
Examples of the colorant that can be contained in the toner include the following.

Examples of the colorant include known organic pigments or oil dyes, carbon black, magnetic substances and the like.

Examples of the cyanide colorant include a copper phthalocyanine compound and its derivative, an anthraquinone compound, and a basic dye lake compound.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds and the like.

Examples of the yellow colorant include a condensed azo compound, an isoindolinone compound, an anthraquinone compound, an azo metal complex, a methine compound, and an allylamide compound.

Examples of the black colorant include carbon black, a magnetic material, or a black colorant using the yellow colorant, magenta colorant, and cyan colorant.

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

<Release agent>
If necessary, a mold release agent that suppresses the occurrence of hot offset during heat fixing of the toner may be used. As the mold release agent, low molecular weight polyolefins, silicone waxes, fatty acid amides, ester waxes, carnauba wax, hydrocarbon waxes and the like can be generally exemplified.

Next, a method for measuring characteristic values according to the present invention and examples described later will be described.

<Calculation of accelerated injection speed>
The speed of accelerated injection of the object to be crushed was calculated from the following equation 1. For the volumetric flow rate, the value obtained by measuring with a flow meter is used.
(Velocity) = (Volume flow rate) / (Effective cross-sectional area of pipe) (Equation 1)

(Measurement of toner particle size distribution)
<Measuring method of toner weight average particle size (D4)>
The weight average particle size (D4) of the toner is measured by the precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter) equipped with a 50 μm aperture tube by the pore electric resistance method. Using the attached dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter) for setting and analysis of measurement data, the measurement data is measured with 25,000 effective measurement channels. Perform analysis and calculate.

As the electrolytic aqueous solution used for the measurement, one in which special grade sodium chloride is dissolved in ion-exchanged water so that the concentration becomes about 1% by mass, for example, "ISOTON II" (manufactured by Beckman Coulter) can be used.

Before performing measurement and analysis, set the dedicated software as follows.

In the "Change standard measurement method (SOM) screen" of the dedicated software, set the total count number of the control mode to 50,000 particles, measure once, and set the Kd value to "Standard particles 10.0 μm" (Beckman Coulter). Set the value obtained using (manufactured by the company). By pressing the threshold / noise level measurement button, the threshold and noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, and the electrolyte to ISOTON II, and check the flash of the aperture tube after measurement.

On the "Pulse to particle size conversion setting screen" of the dedicated software, set the bin spacing 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) Put about 200 ml of the electrolytic aqueous solution in a 250 ml round bottom beaker made of glass dedicated to Multisizer 3, set it on a sample stand, and stir the stirrer rod counterclockwise at 24 rpm. Then, the dirt and air bubbles in the aperture tube are removed by the "aperture flash" function of the analysis software.
(2) Approximately 30 ml of the electrolytic aqueous solution is placed in a 100 ml flat-bottomed beaker made of glass, and "Contaminone N" (nonionic surfactant, anionic surfactant, organic builder) is used as a dispersant in the electrolytic aqueous solution for precise measurement of pH 7. Add about 0.3 ml of a diluted solution obtained by diluting a 10% by mass aqueous solution of a neutral detergent for cleaning a vessel, manufactured by Wako Pure Chemical Industries, Ltd.) with ion-exchanged water 3 times by mass.
(3) Two oscillators with an oscillation frequency of 50 kHz are built in with the phase shifted by 180 degrees, and are installed in the water tank of the ultrasonic disperser "Ultrasonic Dispension System Tetora 150" (manufactured by Nikkaki Bios) with an electrical output of 120 W. A predetermined amount of ion-exchanged water is added, and about 2 ml of the Contaminone N is added into the 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 level of the electrolytic solution in the beaker is maximized.
(5) With the electrolytic aqueous solution in the beaker of (4) being irradiated with ultrasonic waves, about 10 mg of toner is added little by little to the electrolytic aqueous solution and dispersed. Then, the ultrasonic dispersion processing is continued for another 60 seconds. For 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, drop the aqueous electrolyte solution of (5) in which toner is dispersed into the round-bottomed beaker of (1) installed in the sample stand, and adjust the measured concentration to about 5%. .. Then, the measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed by the dedicated software attached to the device, and the weight average particle size (D4) is calculated. The "average diameter" of the analysis / volume statistical value (arithmetic mean) screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4).

<Measuring method of number average particle size (D1) of toner>
In the step (7) of the method for measuring the weight average particle size (D4) of toner, the number of "average diameters" on the analysis / number statistical value (arithmetic mean) screen when graph / number% is set with the dedicated software. The average particle size (D1).

<Manufacturing example of polyester resin L>
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 72.0 parts by mass (0.20 mol; 100.0 mol% based on the total number of moles of polyhydric alcohol)
-Terephthalic acid: 28.0 parts by mass (0.17 mol; 100.0 mol% with respect to the total number of moles of polyvalent carboxylic acid)
-Tin 2-ethylhexanoate (esterification catalyst): 0.5 parts by mass The above materials were weighed in a cooling tube, a stirrer, a nitrogen introduction tube, and a reaction vessel equipped with a thermocouple. Next, the inside of the flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and the reaction was carried out for 4 hours while stirring at a temperature of 200 ° C.

Further, the pressure in the reaction vessel was lowered to 8.3 kPa, maintained for 1 hour, cooled to 180 ° C., and returned to atmospheric pressure.

・ Trimellitic acid anhydride:
3 parts by mass (0.01 mol; 4.0 mol% based on the total number of moles of polyvalent carboxylic acid)
-Tert-Butylcatechol (polymerization inhibitor): 0.1 part by mass Then, the above material was added, the pressure in the reaction vessel was lowered to 8.3 kPa, and the reaction was carried out for 1 hour while maintaining the temperature at 180 ° C., ASTM D36. After confirming that the softening point measured according to −86 reached 90 ° C., the temperature was lowered to stop the reaction, and a polyester resin L as 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 mol; 100.0 mol% based on the total number of moles of polyhydric alcohol)
·Terephthalic acid:
18.3 parts by mass (0.11 mol; 65.0 mol% based on the total number of moles of polyvalent carboxylic acid)
・ Fumaric acid:
2.9 parts by mass (0.03 mol; 15.0 mol% based on the total number of moles of polyvalent carboxylic acid)
-Tin 2-ethylhexanoate (esterification catalyst): 0.5 parts by mass The above materials were weighed in a cooling tube, a stirrer, a nitrogen introduction tube, and a reaction vessel equipped with a thermocouple. Next, the inside of the flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and the reaction was carried out for 2 hours while stirring at a temperature of 200 ° C.

Further, the pressure in the reaction vessel was lowered to 8.3 kPa, maintained for 1 hour, cooled to 180, and returned to atmospheric pressure.

・ Trimellitic acid anhydride:
6.5 parts by mass (0.03 mol; 20.0 mol% based on the total number of moles of polyvalent carboxylic acid)
-Tert-Butylcatechol (polymerization inhibitor): 0.1 part by mass Then, the above material was added, the pressure in the reaction vessel was lowered to 8.3 kPa, and the reaction was carried out for 15 hours while maintaining the temperature at 160 ° C., ASTM D36. After confirming that the softening point measured according to −86 reached 137 ° C., the temperature was lowered to stop the reaction, and the polyester resin H as a binder resin component was obtained.

<Crystalline polyester resin>
-1,6-Hexanediol:
34.5 parts by mass (0.29 mol; 100.0 mol% based on the total number of moles of polyhydric alcohol)
・ Dodecanedioic acid:
65.5 parts by mass (0.28 mol; 100.0 mol% based on the total number of moles of polyvalent carboxylic acid)
-Tin 2-ethylhexanoate: 0.5 parts by mass The above materials were weighed in a cooling tube, a stirrer, a nitrogen introduction tube, and a reaction vessel equipped with a thermocouple. After replacing the inside of the flask with nitrogen gas, the temperature was gradually raised while stirring, and the reaction was carried out for 3 hours while stirring at a temperature of 140 ° C.

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

Further, after gradually releasing the pressure in the reaction vessel and returning it to normal pressure, one or more aliphatic compounds selected from the group consisting of aliphatic monocarboxylic acids and aliphatic monoalcohols shown in Table 2 Was added in an amount of 7.0 mol% with respect 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 inside of the reaction vessel was reduced to 5 kPa or less and reacted at 200 ° C. for 3 hours to obtain a crystalline polyester resin.

<Manufacturing of coarsely crushed toner>
・ Amorphous polyester resin L 80 parts by mass ・ Amorphous polyester resin H 20 parts by mass ・ Crystalline polyester resin 5 parts by mass ・ Fisher Tropsch wax (hydrocarbon wax, peak temperature of maximum heat absorption peak 90 ° C) 8 parts by mass ・C. I. Pigment Blue 15: 37 parts by mass After mixing the above materials with a Henshell mixer (FM-75 type, manufactured by Mitsui Mine Co., Ltd.) at a rotation speed of 20 s ^-1 and a rotation time of 5 min, a twin-screw kneader (PCM). Kneaded with -30 type, manufactured by Ikekai Co., Ltd.). The barrel temperature at the time of 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 Meter Co., Ltd. The obtained kneaded product was cooled and coarsely pulverized with a pin mill to a volume average particle size of 100 μm or less to obtain a coarsely crushed product.

<Manufacturing equipment 1>
As a configuration of the crusher, a mechanical crusher (Turbo Mill T250-CRS-Rotor shape RS type manufactured by Turbo Industries) is modified to supply a raw material supply method by accelerated injection, and a supply mechanism that can freely adjust the supply direction. installed. That is, it is possible to change the speed of accelerated injection at the time of supplying the raw material and the angle θ formed by the introduction direction of the object to be crushed in the left figure in FIG. 2 and the tangential direction at the raw material introduction port. The ratio Lj / Lr of the distance Lj from the end of the rotor on the supply port 101 side to the raw material supply port 201 with respect to the total length Lr of the rotor in FIG. 3 was set to 0.1. The configuration is shown in Table 1. The tooth configuration in Table 1 represents the shapes of the rotor and the stator. In the parallel teeth, the distance Da between the concave and convex portions of the rotor and the stator is 1.3 mm, and the distance Db between the convex portions of the rotor and the stator is 1.0 mm.

<Manufacturing equipment 2>
As a configuration of the crusher, a mechanical crusher (Turbo Mill T250-CRS-Rotor shape RS type manufactured by Turbo Industries) is modified to supply a raw material supply method by accelerated injection, and a supply mechanism that can freely adjust the supply direction. installed. Lj / Lr was set to 0.3. The configuration is shown in Table 1.

<Manufacturing equipment 3>
A mechanical crusher (Turbo Mill T250-CRS-Rotor Shape RS Type) manufactured by Turbo Industries, Ltd. was used as the configuration of the crusher. The configuration is shown in Table 1.

<Manufacturing equipment 4>
As the configuration of the crushing device, a mechanical crusher (Turbo Mill T250-CRS-Rotor shape RS type manufactured by Turbo Industries, Ltd.) was modified, and the raw material supply method was set to the same accelerated injection as that of the manufacturing device 1, as shown in FIG. A device was used in which the teeth of the rotor and the stator had irregularities and meshed with each other. The configuration is shown in Table 1.

<Toner manufacturing method 1>
In the configuration of the apparatus 1, θ was set to 55 °, the feed of the coarse crushed product was 10 kg / h, the rotation speed of the rotor was 170 m / s, the cold air temperature was −10 ° C., and the cold air volume was 8 m ³ / 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 at this time was 22.7 m / s.

<Manufacturing examples of toner manufacturing methods 2 to 12>
In the toner manufacturing methods 2 to 12, the apparatus configuration, the speed at which the object to be crushed (coarse crushed object) was accelerated and injected, and θ were changed as shown in Table 2 and the operation was performed. The operating conditions other than the above are the same as those in the manufacturing method 1.

<Example 1>
The pulverizer was operated according to the toner manufacturing method 1, the average particle sizes D4 and D1 were measured, and D4 and the particle size distribution index D4 / D1 were evaluated.

[Evaluation of D4]
The particle size of the toner particles after the pulverization treatment was evaluated. The evaluation criteria are shown below.
A: D4 is less than 4.2 μm (very good)
B: D4 is 4.2 μm or more and less than 4.4 μm (excellent)
C: D4 is 4.4 μm or more and less than 4.6 μm (a level that is not a problem in the present invention).
D: D4 is 4.6 μm or more (not acceptable in the present invention)

[Evaluation of D4 / D1]
The particle size distribution of the toner particles after the pulverization treatment was evaluated. The smaller the value of D4 / D1, which is a particle size distribution index, the sharper the distribution. As described above, when the particle size distribution is sharp, unnecessary particle size components to be removed in the classification step after the fine pulverization step are reduced. Therefore, it is possible to maintain high productivity. The evaluation criteria are shown below.
A: D4 / D1 is less than 1.57 (very good)
B: D4 / D1 is 1.57 or more and less than 1.59 (excellent)
C: D4 / D1 is 1.59 or more and less than 1.62 (a level that is not a problem in the present invention).
D: D4 / D1 is 1.62 or more (not acceptable in the present invention)

<Examples 2 to 7 and Comparative Examples 1 to 5>
The evaluation was carried out in the same manner as in Example 1 except that the manufacturing method was changed. The evaluation results are shown in Table 3.

In Comparative Example 1, the supply of the object to be crushed was not accelerated and crushed, and the usual supply method was adopted. It is presumed that the evaluation of D4 deteriorated because the crushing effect due to the collision at the time of supply could not be obtained.

In Comparative Example 2, the crushed teeth are meshed teeth. It is presumed that the object to be crushed by the accelerated injection directly collides with the rotor, but the evaluation of D4 deteriorates due to the subsequent insufficient crushing in the crushing processing chamber.

Comparative Example 3 is an example in which the raw material supply position is shifted to the discharge port side. It is presumed that the object to be crushed by the accelerated injection directly collides with the rotor, but the evaluation of D4 deteriorates due to the subsequent insufficient crushing in the crushing processing chamber.

Comparative Example 4 is an example in which the accelerated injection speed of compressed air is increased to 51.9 m / sec. It is presumed that the evaluation of D4 / D1 deteriorated due to the excessive collision energy due to the accelerated injection and the generation of overcrushed toner fine particles.

Comparative Example 5 is an example in which the accelerated injection speed of compressed air is reduced to 8.8 m / sec. It is presumed that the evaluation of D4 deteriorated because the collision energy sufficient for crushing could not be obtained.

101: Supply port, 102: Swirl chamber, 103: Rotor, 104: Stator, 105: Rear chamber, 106: Discharge port, 107: Central rotary shaft (rotary shaft), 108: Cold air generator, 109: Cold water supply Port, 110: Cold water discharge port, 201: Raw material supply port

Claims (2)

A method for producing a toner, which comprises a step of finely pulverizing an object to be pulverized containing a binder resin and a colorant by a pulverizing means.
The crushing means is
A powder supply mechanism that supplies the object to be crushed,
A stator having a plurality of protrusions and recesses on the inner peripheral surface,
A rotor attached to the central rotation axis and having a plurality of protrusions and recesses on the outer peripheral surface,
A powder discharge port that discharges finely pulverized material and
Have,
The stator contains the rotor, and the rotor is arranged so that the surface of the stator and the surface of the rotor face each other with a predetermined gap.
The protrusions and recesses existing 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 axis.
The object to be crushed is acceleratedly jetted by the powder supply mechanism, supplied from the supply port so as to directly collide with the outer peripheral surface of the rotor, and crushed formed in the gap between the stator and the rotor. In the region, the rotation of the rotor causes fine grinding.
When the rotor is divided into four equal parts along the central rotation axis and each of the four equal parts is divided into first to fourth regions along the flow of the object to be crushed.
(I) The position where the object to be crushed is acceleratedly jetted by the powder supply mechanism and collides with the rotor is the first region.
(Ii) The powder discharge port is provided in the region of the stator facing the fourth region.
The accelerated air wind speed when the object to be crushed is acceleratedly injected and supplied is 10 m / sec or more and 50 m / sec or less when passing through the supply port.
A method for manufacturing toner, which is characterized by the fact that. The powder supply mechanism supplies the object to be crushed so as to face the rotation direction of the rotor, and the introduction direction of the object to be crushed and the powder supply on a plane perpendicular to the rotation axis of the rotor. The method for manufacturing a toner according to claim 1, wherein the angle θ formed by the mechanism and the stator is 20 ° or more and 80 ° or less.

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