JP2022025737A - Method for manufacturing toner - Google Patents

Abstract

To provide a method for manufacturing a toner with a smaller particle diameter, and a method for manufacturing a toner that prevents fusion in a device.SOLUTION: A method for manufacturing toner has the steps of: fusing and kneading a mixture containing a binder resin and a colorant; cooling the obtained kneaded material; roughly grinding the cooled material; and pulverizing the roughly ground material with pulverization means. The pulverization means has a powder supply port A101, a stator 104 that has a plurality of projections and recesses on an inner peripheral surface, a rotor 103 that is attached to a center rotation shaft and has a plurality of projections and recesses on an outer peripheral surface, and a powder discharge port 106. The stator includes the rotor, and the surface of the stator and the surface of the rotor are opposite to each other with a predetermined gap therebetween to form a processing part for performing pulverization. In the pulverization step, an air current including the roughly ground material is taken into the pulverization means from the powder supply port of the pulverization means, and pulverization is performed by the rotating rotor. The introduction of the roughly ground material is performed while changing an angle of introducing the roughly ground material to the air current flowing through piping from a powder introduction port.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electrograph, an image forming method for visualizing an electrostatic charge image, and a method for producing toner used in a toner jet.

In an image forming method for visualizing an electrophotographic or electrostatic charge image, a toner for developing the electrostatic charge image is used. The method for producing toner is roughly classified into a pulverization method and a polymerization method, and a simple production method includes a pulverization method. As a general manufacturing method of the pulverization method, a binder resin, a colorant, and if necessary, a charge control agent, a mold release agent, a fluidity imparting agent, and a magnetic material are added and mixed, melt-kneaded, and cooled and solidified. After that, the kneaded product is pulverized by a pulverizing means. After that, the toner is used for image formation through a step of classifying the toner into a desired particle size distribution and a step of adding a fluidizing agent as needed. Further, in the case of the toner used in the two-component developing method, various magnetic carriers and the above toner are mixed and then used for image formation.
Various crushing devices are used as the crushing means, but in recent years, in order to reduce CO ₂ emissions, energy saving of the devices is required, and mechanical crushers with low power consumption are often used. For example, a rotor supported by a central rotation shaft and having a plurality of protrusions and recesses on an outer peripheral surface in a casing having an input port and a discharge port for an object to be crushed, and a rotor outside the rotor. A rotor and a stator are provided with a predetermined gap between the outer peripheral surface of the rotor and a stator having a plurality of convex portions and concave portions on the inner peripheral surface thereof, and the rotor and the stator are carried by the airflow flowing from the inlet to the outlet. There is known a mechanical crusher that crushes the object to be crushed by colliding with the convex portion or the concave portion of the rotor or the stator when the object to be crushed passes through the processing portion facing the object.
In recent years, there has been a demand for smaller toner particles from the viewpoint of improving image quality. In order to reduce the particle size of toner, it is effective to rotate the rotor at high speed and to narrow the distance between the rotor and the stator in the mechanical crusher as described above. However, when the rotor is rotated at high speed, the temperature of the object to be crushed and the temperature of the air in the crushing chamber rise due to frictional heat during crushing, and in-machine fusion is likely to occur. In-flight fusion is also likely to occur when the distance between the rotor and the stator is narrowed.
A mechanical crusher in which the shape of the groove of the stator is devised for the production of toner particles having a smaller particle size is disclosed (Patent Document 1).

Japanese Unexamined Patent Publication No. 2005-21768

The mechanical crusher described in Patent Document 1 can produce toner particles having a smaller particle size by devising the shape of the groove of the stator.
However, it has been found that the mechanical crusher described in Patent Document 1 has room for improvement in terms of suppressing in-machine fusion when producing toner particles having a smaller particle size.
When the number of revolutions of the rotor is increased in order to pulverize the toner particles to a smaller particle size and obtain a finely pulverized product, or as a means for improving productivity, the input amount of the object to be pulverized per unit time is set. When the number is increased, the temperature inside the machine and the temperature of the object to be crushed become more remarkable, so that in-machine fusion is likely to occur.
Further, if the temperature inside the machine and the temperature of the object to be crushed become remarkable, the surface of the object to be crushed may be partially melted and the objects to be crushed may be bonded to each other, and the particle size of the pulverized product may not be stable. ..
The present invention has been made to solve the above-mentioned problems, and when producing toner particles having a smaller particle size, it is possible to suppress in-machine fusion and achieve improvement in toner productivity. It provides a method for producing toner particles.

The present invention is a melt-kneading step of melt-kneading a mixture containing a binder resin and a colorant.
Cooling process to cool the resulting kneaded product,
A method for producing a toner, which comprises a coarse pulverization step of coarsely pulverizing a cooled product and a fine pulverization step of pulverizing the coarsely pulverized material by a pulverizing means.
The crushing means includes a powder supply port A for supplying the coarsely crushed material into the crushing means, and
A stator having a plurality of protrusions and recesses on the inner peripheral surface, a rotor attached to the central rotation shaft and having a plurality of protrusions and recesses on the outer peripheral surface, and for discharging crushed powder. With a powder outlet,
The stator contains the rotor, and the surface of the stator and the surface of the rotor face each other with a predetermined gap to form a processing portion for fine pulverization.
A pipe A through which an air flow flows is connected to the powder supply port A.
On the upstream side of the powder supply port A in the pipe A, a powder input port B for charging the coarsely pulverized material into the pipe A is provided.
In the fine pulverization step, the coarse pulverized material is charged into the air flow flowing through the pipe A from the powder charging port B, and the air flow containing the formed coarse pulverized material is supplied to the powder of the fine pulverization means. The coarsely pulverized material is taken into the pulverizing means from the mouth A, the coarsely pulverized material is supplied to the processing portion while maintaining the air flow, and the pulverization is performed by a rotating rotor.
The present invention relates to a method for producing toner, which comprises charging the coarsely pulverized material from the powder charging port B into an air flow flowing through the pipe A while changing the angle at which the coarsely crushed material is charged.

According to the present invention, it is possible to provide a method for producing toner particles, which can suppress in-machine fusion when producing toner particles having a smaller particle size and achieve improvement in toner productivity. can.

It is a schematic diagram of the mechanical crusher used in this invention. It is the schematic of the vicinity of the powder input port of the mechanical crusher used in this invention.

In the present invention, the description of "○○ or more and XX or less" and "○○ to XX" indicating a numerical range means a numerical range including a lower limit and an upper limit which are end points, unless otherwise specified.

The method for producing toner particles of the present invention is
A melt-kneading step of melt-kneading a mixture containing a binder resin and a colorant,
Cooling process to cool the resulting kneaded product,
A method for producing a toner, which comprises a coarse pulverization step of coarsely pulverizing a cooled product and a fine pulverization step of pulverizing the coarsely pulverized material by a pulverizing means.
The crushing means includes a powder supply port A for supplying the coarsely crushed material into the crushing means, and
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 outlet for discharging crushed powder and
Have,
The stator contains the rotor, and the surface of the stator and the surface of the rotor face each other with a predetermined gap to form a processing portion for fine pulverization.
A pipe A through which an air flow flows is connected to the powder supply port A.
On the upstream side of the powder supply port A in the pipe A, a powder input port B for charging the coarsely pulverized material into the pipe A is provided.
In the fine pulverization step, the coarse pulverized material is charged into the air flow flowing through the pipe A from the powder charging port B, and the air flow containing the formed coarse pulverized material is supplied to the powder of the fine pulverization means. The coarsely pulverized material is taken into the pulverizing means from the mouth A, the coarsely pulverized material is supplied to the processing portion while maintaining the air flow, and the pulverization is performed by a rotating rotor.
It is characterized in that the coarsely crushed material is charged while changing the angle at which the coarsely crushed material is charged into the air flow flowing through the pipe A from the powder charging port B.

According to the studies by the present inventors, the toner that can suppress in-machine fusion when producing toner particles having a smaller particle size by the above manufacturing method and achieves improvement in toner productivity. A method for producing particles can be provided.

The reason why the method for producing the toner particles can obtain an unprecedented excellent effect is considered as follows.

When a predetermined amount of coarse crushed material is charged into the powder supply port 101 of the mechanical crusher shown in FIG. 1, the crushed material passes through the spiral chamber 1201 communicating with the powder supply port and is fixed to the rotor 103. It is introduced into a pulverization processing chamber (a processing unit for pulverizing) which is a gap between the child 104 and the child 104. Then, the rotor 103, which is attached to the central rotation shaft 107 and has a plurality of convex portions and concave portions on the outer peripheral surface that rotates at high speed in the crushing processing chamber, and the plurality of convex portions and concave portions are provided on the inner peripheral surface. It is instantaneously crushed by the impact generated between the stator and the stator 104. After that, it is discharged through the powder discharge port 106.

Here, the material to be crushed charged from the powder supply port is a rotor due to a force parallel to the central rotation axis due to the airflow from the powder supply port to the powder discharge port and collision with the convex and concave portions of the rotor. Receives a force in the normal direction of the outer circumference of. As a result, the object to be crushed has a straight "spiral trajectory" in the direction of rotation of the rotor, starting from the gap between the rotor and the stator near the powder supply port and ending near the powder discharge port. It is thought that it will be crushed while moving.

Based on the above findings, as shown in FIG. 2, in the present invention, the pipe A201 through which the air flow flows is connected to the powder supply port A101, and the pipe A201 is connected to the upstream side of the powder supply port in the pipe. A powder charging port B202 for charging the coarsely pulverized material into the pipe is provided. Then, in the present invention, the coarsely pulverized material is charged while changing the angle 203 for charging the coarsely pulverized material into the airflow flowing through the pipe from the powder charging port, so that the toner particles having a smaller particle size are charged. It is possible to provide a method for producing toner particles, which can suppress in-machine fusion and achieve improvement in toner productivity.

By changing the angle at which the coarsely crushed material is charged into the airflow flowing through the pipe from the powder charging port, the trajectory of the coarsely crushed material flowing through the pipe is changed. When the trajectory of the coarsely crushed material changes, the position of the rotor in the rotation direction when the coarsely crushed material enters the crushing processing chamber changes. As a result, the spiral trajectory in the direction of rotation of the rotor changes, starting from the gap between the rotor and the stator in the vicinity of the powder supply port and ending in the vicinity of the powder discharge port. That is, by changing the angle at which the coarsely crushed material is charged into the air flow flowing through the pipe from the powder charging port, the trajectory of the coarsely crushed material in the crushing processing chamber can be changed. Therefore, the coarsely crushed material passes through many parts of the surface of the stator and rotor in the crushing processing chamber, and local passage can be reduced, and the temperature inside the crusher and the temperature of the coarsely crushed material rise significantly. Can be suppressed.

If the angle at which the coarsely crushed material is charged into the airflow flowing from the powder charging port to the pipe is not changed, the coarsely crushed material is crushed without changing the spiral trajectory of the coarsely crushed material. Flow becomes local. Therefore, when the coarsely crushed material is crushed, the temperature inside the crusher and the temperature of the coarsely crushed material may rise remarkably due to the frictional heat at the time of crushing. As a result, when toner is fused in the machine starting from the temperature rise part, or the surface of the coarsely crushed material is partially melted and the coarsely crushed material is bonded to each other, the particle size of the finely crushed product becomes large. It may not be stable.

In the present invention, the angle at which the coarsely pulverized material is charged into the airflow flowing through the pipe from the powder charging port may be continuously changed or discontinuously changed.

In the present invention, the angle at which the coarsely pulverized material is charged into the air flow flowing through the pipe A from the powder charging port B (203 in FIG. 2) is 20 ° or more and 160 ° or less (however, the angle in the longitudinal direction of the pipe A is 0). °.) Is preferable.

By controlling the angle within the above range, the roughened object can pass through many parts of the surfaces of the stator and rotor in the pulverization processing chamber. Therefore, when producing toner particles having a smaller particle size, it is possible to provide a method for producing toner particles that can suppress in-machine fusion and achieve improvement in toner productivity.

In the present invention, it is preferable that the coarsely crushed material is charged while changing the angle at which the coarsely crushed material is charged into the airflow flowing through the pipe A from the powder charging port B by 20 ° or more, and the coarsely pulverized material is charged while changing by 70 ° or more. It is more preferable that the material is charged, and it is more preferable that the coarsely pulverized material is charged while changing the temperature by 140 ° or more.

By controlling the angle within the above range, the coarse crushed material can pass through many parts of the surface of the stator and rotor in the pulverization processing chamber. Therefore, when producing toner particles having a smaller particle size, it is possible to provide a method for producing toner particles that can suppress in-machine fusion and achieve improvement in toner productivity.

In the present invention, the distance between the powder charging port and the central rotation axis of the rotor (204 in FIG. 2) is preferably 2 m or less. By controlling the distance between the powder charging port and the central rotation axis of the rotor within the above range, the coarse material can pass through many parts of the stator and rotor surfaces in the pulverization processing chamber. Therefore, when producing toner particles having a smaller particle size, it is possible to provide a method for producing toner particles that can suppress in-machine fusion and achieve improvement in toner productivity.

In the present invention, the volume average particle size of the coarsely pulverized product is preferably 65 μm or less. By setting the volume average particle size of the coarsely crushed material to 65 μm or less, it is possible to suppress an increase in the temperature of the material to be crushed. Therefore, when producing toner particles having a smaller particle size, it is possible to provide a method for producing toner particles that can suppress in-machine fusion and achieve improvement in toner productivity.

Next, a procedure for manufacturing toner particles by the manufacturing method 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 internal additive, 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 therein. 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 Machinery Co., Ltd. , A twin-screw extruder manufactured by K.C.K., a co-kneader manufactured by Buss, a PCM type twin-screw extruder manufactured by Ikekai, and the like 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 a mechanical crusher such as an innomizer (manufactured by Hosokawa Micron), a cryptron (manufactured by Kawasaki Heavy Industries), a super rotor (manufactured by Nisshin Engineering), and a turbo mill (manufactured by Turbo Industries). In the pulverization step, the toner is pulverized step by step to a predetermined toner particle size.

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.

<Bundling resin>
As the binder resin used for the toner used in the electrograph, a general resin can be used. For example, polyester resin, styrene-acrylic acid copolymer, polyolefin resin, vinyl resin, fluororesin, phenol resin, silicone resin, epoxy resin and the like. 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 cyan-based colorant include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds.

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 condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, allylamide compounds and the like.

Examples of the black colorant include carbon black, a magnetic substance, or a color toned black 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 heating and fixing of the toner may be used. As the release agent, low molecular weight polyolefins, silicone waxes, fatty acid amides, ester waxes, carnauba waxes, hydrocarbon waxes and the like can be generally exemplified.

<Measurement method of particle size distribution of toner particles>
The particle size distribution of the toner particles is measured as follows.

As the measuring device, a 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 is used. For the setting of measurement conditions and the analysis of measurement data, the attached dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter) is used. The measurement is performed with 25,000 effective measurement channels.

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.

On the "Change standard measurement method (SOM)" screen of the dedicated software, set the total count number in the control mode to 50,000 particles, measure once, and set the Kd value to "standard particles 10.0 μm" (Beckman Coulter). The value obtained by using (manufactured by) is set.

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 electrolytic aqueous solution to ISOTON II, and check "Flash of 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 from 1 μm to 30 μm.

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 exclusively for Multisizer 3, set it on the 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 dedicated software.
(2) Put about 30 mL of the electrolytic aqueous solution in a 100 mL flat-bottomed beaker made of glass. Among them, as a dispersant, "Contaminone N" (a 10% by mass aqueous solution of a neutral detergent for cleaning a pH 7 precision measuring instrument consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd. ) Is diluted about 3 times by mass with ion-exchanged water, and about 0.3 mL of the diluted solution is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are built in with their phases shifted by 180 degrees, and an ultrasonic disperser "Ultrasonic Dispersion System Tetora 150" (manufactured by Nikkaki Bios) with an electrical output of 120 W is prepared. About 3.3 L of ion-exchanged water is put into the water tank of the ultrasonic disperser, and about 2 mL of contaminone N is added to this water tank.
(4) The beaker of (2) above 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) In a state where the electrolytic aqueous solution in the beaker of (4) is 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, the electrolytic aqueous solution of (5) in which toner is dispersed is dropped onto the round bottom beaker of (1) installed in the sample stand, and the measured concentration is adjusted 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).

<Measurement method of particle size distribution of coarsely pulverized particles>
A particle size distribution measuring device LA-950V2 (manufactured by HORIBA, Ltd.) was used to measure the particle size distribution of the coarsely pulverized product. This device can measure particle sizes from 0.01 μm to 3000 μm using a laser scattering method. The particle size of the coarsely pulverized product was measured by wet measurement using this device. As a method of wet measurement, a coarsely pulverized product was mixed with an aqueous medium and ultrasonically dispersed using "Contaminone N" as a dispersant as in the above Coulter counter, and introduced into the apparatus. The measurement was carried out using 1.53 as the value of the refractive index of the sample (coarse pulverized product) and 1.33 as the value of the refractive index of the dispersion medium.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

<Production example of amorphous 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% 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 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 an amorphous polyester resin L was obtained as the binder resin.

<Production example of amorphous 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 ° C., 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 an amorphous polyester resin H was obtained as the binder resin.

<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 the pressure in the reaction vessel is gradually released and returned to normal pressure, one or more aliphatic compounds selected from the group consisting of aliphatic monocarboxylic acids and aliphatic monoalcohols are used as the raw material monomer 100. 7.0 mol% was added to 0 mol%, 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.

<Toner manufacturing example>
・ 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) 5 parts by mass ・C. I. Pigment Blue 15:37 parts by mass 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, and then 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 60 μm to obtain a toner coarse pulverized product 1.

The weight average particle size of the finely pulverized products obtained in the following Examples and Comparative Examples was measured according to the method for measuring the weight average particle size (D4) of the toner particles.

[Example 1]
In this embodiment, the crushing apparatus shown in FIGS. 1 and 2 is used.

The configuration of the crushing device shown in FIGS. 1 and 2 is such that in a mechanical crusher (Turbo Mill T250-CRS-Rotor shape RS type manufactured by Turbo Industries, Ltd.), the inside is inserted into the powder supply port A (powder supply port 101). A pipe A (pipe 201) through which an air flow flows is connected, and a powder input port B (powder) for charging the coarse pulverized material into the pipe A is connected to the upstream side of the powder supply port A in the pipe A. A body inlet 202) was provided. Further, it was modified so that the angle of the powder charging port B could be changed.

In Example 1, pulverization was performed while continuously changing the angle of the powder charging port B from 20 ° to 160 ° at a rate of 10 ° / 1 sec. At this time, the angle in the longitudinal direction of the pipe A was set to 0 °. After reaching the powder inlet B from 20 ° to 160 °, the angle is changed from 160 ° to 20 ° at a speed of 10 ° / 1 sec, and then again from 20 ° to 160 ° at 10 ° / 1 sec. The speed was changed to reciprocate from 20 ° to 160 ° until the grinding was completed.

Hereinafter, when the angle of the powder charging port B (angle of the powder charging port 203) is changed from 〇〇 ° to XX °, after the change from 〇〇 ° to XX °, XX ° to 〇〇 It shall be changed at the same speed as the change from 〇〇 ° to XX ° to °, and then the reciprocating motion to change from 〇〇 ° to XX ° again shall be repeated.

Further, the distance between the powder charging port B and the center rotation axis of the rotor (distance 204 between the powder charging port and the center rotation axis of the rotor) was set to 2 m.

Using the above mechanical crusher, the finely pulverized product was manufactured under the conditions shown below using the toner crushed product 1 obtained in the production example of the toner raw material (coarse crushed product).

<Condition 1>
Using the crushing device shown in FIGS. 1 and 2, 30 kg / h of coarsely crushed material 1 and 8 m ³ / min of cold air are flowed in from the powder inlet B, the gap between the rotor and the stator is 1.0 mm, and the cold air temperature-. The coarsely crushed material 1 was pulverized under the condition of 10 ° C.

In the manufacturing method of condition 1, the peripheral speed of the rotor is first set so that the weight average particle size of the finely pulverized product is in the range of 5.0 to 5.2 μm, and then continuous manufacturing is performed for 10 hours under the same conditions. A finely pulverized product of 300 kg was obtained.

<Condition 2>
Using the crushing device shown in FIGS. 1 and 2, 30 kg / h of coarsely crushed material 1 and 8 m ³ / min of cold air are flowed in from the powder inlet B, the gap between the rotor and the stator is 1.0 mm, and the cold air temperature-. The coarsely crushed material 1 was pulverized under the condition of 10 ° C.

In the manufacturing method of condition 2, the peripheral speed of the rotor is first set so that the weight average particle size of the finely pulverized product is in the range of 4.0 to 4.2 μm, and then continuous manufacturing is performed for 10 hours under the same conditions. A finely pulverized product of 300 kg was obtained.

Since the set particle size under this condition is smaller than the set particle size (5.0 to 5.2 μm) shown in condition 1, the peripheral speed of the rotor is increased. rice field.

[Evaluation of in-flight fusion property]
After manufacturing for 10 hours continuously, the apparatus was stopped, and the degree of toner adhesion (dirt) on the rotor and stator was visually confirmed.

The evaluation rank is as follows.
A ... Very good with almost no adhesion.
B ... Slight adhesion is observed, but there is no problem in practical use.
C ... Adhesion is observed and there is a problem in practical use.

[Evaluation of particle size stability]
The produced finely pulverized product was sampled every 2 hours, the weight average particle size (D4) was measured, and the particle size stability of the finely pulverized product was evaluated.

The evaluation rank is as follows.
A ... The particle size within the set range is obtained, which is very excellent.
B: Although it deviates from the set value, it is within 0.3 μm, which is a level at which there is no practical problem.
C: There is a practical problem that the value deviates from the set value by 0.3 μm or more.

In each of the above evaluation items, the manufacturing method of Example 1 was all judged as A.

[Example 2]
The coarsely crushed toner obtained in the production example of the toner raw material (coarse crushed product) was roughly crushed so that the volume average particle size was 100 μm, and the evaluation conditions were evaluated by the same method as in Example 1 except that only condition 2 was evaluated. Carried out.

[Example 3]
The evaluation was carried out in the same manner as in Example 2 except that the distance between the powder charging port B and the central rotation axis of the rotor was set to 3 m.

[Example 4]
The evaluation was carried out in the same manner as in Example 3 except that the powder charging port B was pulverized while continuously changing the angle from 20 ° to 160 ° at a rate of 1 ° / 1 sec.

[Example 5]
The same method as in Example 3 except that pulverization was performed while changing the angle of the powder charging port B from 20 ° to 160 ° at a speed of 1 ° / 1 min (discontinuous change of 1 ° every 1 minute). The evaluation was carried out at.

[Example 6]
The same method as in Example 3 except that pulverization was performed while changing the angle of the powder charging port B from 20 ° to 160 ° at a speed of 10 ° / 10 min (discontinuous change of 10 ° every 10 minutes). The evaluation was carried out at.

[Example 7]
The same method as in Example 3 except that pulverization was performed while changing the angle of the powder charging port B from 20 ° to 90 ° at a speed of 10 ° / 10 min (discontinuous change of 10 ° every 10 minutes). The evaluation was carried out at.

[Example 8]
The same method as in Example 3 except that pulverization was performed while changing the angle of the powder charging port B from 20 ° to 40 ° at a speed of 10 ° / 10 min (discontinuous change of 10 ° every 10 minutes). The evaluation was carried out at.

[Example 9]
The same method as in Example 3 except that pulverization was performed while changing the angle of the powder charging port B from 140 ° to 160 ° at a speed of 10 ° / 10 min (discontinuous change of 10 ° every 10 minutes). The evaluation was carried out at.

[Example 10]
The same method as in Example 3 except that pulverization was performed while changing the angle of the powder charging port B from 10 ° to 20 ° at a speed of 10 ° / 10 min (discontinuous change of 10 ° every 10 minutes). The evaluation was carried out at.

[Example 11]
The same method as in Example 3 except that pulverization was performed while changing the angle of the powder charging port B from 160 ° to 170 ° at a speed of 10 ° / 10 min (discontinuous change of 10 ° every 10 minutes). The evaluation was carried out at.

The evaluation results of Examples 2 to 11 are shown in Table 1.

[Comparative Example 1]
The angle of the powder charging port B was fixed at 90 °, and the evaluation was carried out in the same manner as in Example 3 except that the evaluation conditions were evaluated under the conditions 1 and 2.

The results of Comparative Example 1 are shown in Table 2.

101: Grinding supply port A, 1021: Swirl chamber, 1022: Swirl chamber outlet, 103: Rotor, 104: Stator, 105: Rear chamber, 106: Powder discharge port, 107: Rotating shaft, 108: Cold air generation Equipment, 109: Cold water supply port, 110: Cold water discharge port, 201: Pipe A, 202: Powder input port B, 203: Powder input port angle, 204: Powder input port and center rotation axis of rotor distance

Claims (3)

A melt-kneading step of melt-kneading a mixture containing a binder resin and a colorant,
Cooling process to cool the resulting kneaded product,
A method for producing a toner, which comprises a coarse pulverization step of coarsely pulverizing a cooled product and a fine pulverization step of pulverizing the coarsely pulverized material by a pulverizing means.
The crushing means includes a powder supply port A for supplying the coarsely crushed material into the crushing means, and
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 outlet for discharging crushed powder and
Have,
The stator contains the rotor, and the surface of the stator and the surface of the rotor face each other with a predetermined gap to form a processing portion for fine pulverization.
A pipe A through which an air flow flows is connected to the powder supply port A.
On the upstream side of the powder supply port A in the pipe A, a powder input port B for charging the coarsely pulverized material into the pipe A is provided.
In the fine pulverization step, the coarse pulverized material is charged into the air flow flowing through the pipe A from the powder charging port B, and the air flow containing the formed coarse pulverized material is supplied to the powder of the fine pulverization means. The coarsely pulverized material is taken into the pulverizing means from the mouth A, the coarsely pulverized material is supplied to the processing portion while maintaining the air flow, and the pulverization is performed by a rotating rotor.
A method for producing toner, characterized in that the coarsely pulverized material is charged while changing the angle at which the coarsely crushed material is charged into the air flow flowing through the pipe A from the powder charging port B. The angle at which the coarsely pulverized material is charged into the airflow flowing through the pipe A from the powder charging port B is changed to 20 ° or more and 160 ° or less (however, the longitudinal angle of the pipe A is 0 °). The method for producing toner according to claim 1, wherein the coarsely pulverized material is charged while being charged. The method for producing toner according to claim 1 or 2, wherein the distance between the powder charging port B and the central rotation axis of the rotor is 2 m or less.

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