JP2022001934A - Classifier to toer and method for manufacturing toner - Google Patents

Abstract

To provide a classifier for toner that indicates a satisfactory yield even when a toner with a small particle diameter is manufactured, and a method for manufacturing toner.SOLUTION: A classifier for toner includes a classifying rotor. A classifying rotor has a plurality of blades that extend from the center of rotation of the classifying rotor toward an outer periphery. The plurality of blades are arranged with a predetermined interval from each other. The interval forms an opening toward a rotation center area of the classifying rotor. The blades are provided to be directed to the upstream side with respect to the direction of rotation of the classifying rotor from a rotation center side end toward an outer peripheral side end of the classifying rotor. The blades each have a bent part. On a cross section when the classifying rotor is cut off in a direction perpendicular to the rotation axis of the classifying rotor, the shape of the blades satisfies a predetermined relational expression. A method for manufacturing toner has a classifying step of performing classifying processing on particles to be classified by using the classifier for toner.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a toner classifier used in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and a toner jet method, and a toner manufacturing 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, high speed, high image quality, and high productivity are required while supporting a wide range of media (paper types). In the toner, the developability and transferability are stabilized by stabilizing the chargeability of the toner with a toner having a small particle size and a sharp particle size distribution, and high image quality can be achieved.
As one of the general methods for producing toner, a melt-kneading pulverization method is known. Specific examples of the method for producing toner particles by the melt-kneading pulverization method are as follows. Toner raw materials such as a binder resin, a colorant, and a mold release agent are melt-kneaded, cooled and solidified, and then the kneaded product is refined by a pulverizing means to obtain toner particles. Then, if necessary, the toner is manufactured by classifying the toner into a desired particle size distribution, adjusting the circularity by spheroidizing the toner particles by heat treatment, or adding a fluidizing agent such as inorganic fine particles.

Various crushing devices are used as crushing means for the kneaded material, and a rotor supported by a central rotation shaft and having a plurality of protrusions and recesses on the outer peripheral surface in a casing having an input port and a discharge port for the material to be crushed. And, on the outside of the rotor, a stator having a predetermined gap with the outer peripheral surface of the rotor is provided, and a stator having a plurality of convex portions and concave portions is provided on the inner peripheral surface thereof. A machine that crushes the object to be crushed by colliding with the convex or concave portion of the rotor or stator when the object to be crushed passes through the processing section where the rotor and stator oppose each other in the airflow flowing through the rotor. A formula crusher (Patent Document 1) and the like are known.
Further, fine powder generated during the pulverization step is mixed in the pulverized product pulverized to a desired particle size by the pulverizer. If this fine powder is present in the toner, it causes problems in the electrophotographic process such as fog, so it is generally removed by a classification process.
As a method for manufacturing a toner having a classification process using a classifier, a method for manufacturing a toner using an airflow type classifier utilizing the Coanda effect (Patent Document 2) and a method for manufacturing a toner using a centrifugal wind classifier are used. A method (Patent Document 3) and the like are known.

When a centrifugal wind classifier is used, the crushed material of the toner raw material, which is the particles to be classified, is conveyed from the inlet to the vicinity of the outer circumference of the classification rotor by the air flow from the outer peripheral side of the classification rotor to the inside, and at the outer circumference of the classification rotor. Centrifugal force is applied by the rotation of the classification rotor. Since the centrifugal force acting on the classified particles is a force toward the outside of the classification rotor and is proportional to the weight of the particles, the centrifugal force acting on the fine particles in the classified particles is larger than the drag force given by the airflow from the outer peripheral side of the classification rotor to the inside. small. Therefore, the classified material that has passed between the blades of the classification rotor and communicated with the inside of the classification rotor is collected by the fine powder collecting means, and the fine powder from the classified particles is removed from the classified particles. It is classified by collecting it.
In addition, it has a plurality of blades arranged at regular intervals on the same circumference, and each blade forms an angle θ of 20 ° to 65 ° with respect to the straight line connecting the center of the classification rotor and the tip of the blade. A method for producing a toner using the classification means arranged in the above method has also been proposed (Patent Document 4). In the classification means used in the manufacturing method, the air entering between the blades from the outside of the classification rotor rotating at high speed is divided into a component directed toward the center of rotation and a component ejected to the outside of the classification rotor. Generate a vortex.

Japanese Unexamined Patent Publication No. 2011-237816 Japanese Unexamined Patent Publication No. 2001-201890 Japanese Unexamined Patent Publication No. 2008-26457 Japanese Unexamined Patent Publication No. 2010-160374

As described above, the classification process is performed by adjusting the balance between the drag force acting on the classified particles and the centrifugal force. However, due to factors such as the turbulence of the airflow in the classifier, the aggregation of the classified particles, the variation in speed when the classified particles approach the classifying rotor, and the generation of vortices between the blades of the classifying rotor. Particles that should not be taken in as fine powder may also be erroneously sucked and removed. The closer the average particle size of the particles to be classified and the particle size of the fine particles to be removed by the classification step, the higher the ratio of removal by erroneous suction. It was confirmed that the rate would decrease.
Further, it is considered that the vortex generated in the toner manufacturing method described in Patent Document 4 is generated in a shape along the blade. When the angle θ formed is present, the vortex is generated outside the classification rotor as compared with the classification rotor arranged on the radial straight line described above, so that the ratio of erroneous suction of the classified particles becomes smaller and the yield is reduced. Was confirmed to improve. However, it was also confirmed that if the angle θ formed is too large, the distance between the blades inside the classification rotor becomes too narrow, and it becomes difficult for fine powder to pass through, so that sufficient fine powder cannot be removed.

As described above, it is required to reduce the particle size of the toner in order to improve the image quality. The particle size of the pulverized product obtained by the pulverization step after the mixture of the toner raw materials is melt-kneaded is dominant with respect to the particle size of the toner finally obtained. Therefore, in order to reduce the particle size of the toner, it is necessary to reduce the particle size of the pulverized product. The classification process is a process for removing fine powder that may be a problem factor in the electrophotographic process. However, when the particle size of the toner is reduced, the average particle size of the pulverized product and the particle size of the fine powder, which is a particle to be removed by the classification step, become close to each other. Therefore, there is a problem that the yield is lowered because some particles that should not be removed because the particle size is appropriate for the toner are also removed as fine particles.
The present disclosure is to solve the above-mentioned problems and provide a toner classifier and a toner manufacturing method that show good yields even when a toner having a small particle size is manufactured.

This disclosure is
A toner rating system equipped with a rating rotor.
The classification rotor has a plurality of blades extending from the rotation center side of the classification rotor to the outer peripheral side.
The plurality of blades are arranged at a predetermined distance from each other.
The spacing forms an opening towards the rotation center region of the classification rotor.
The blades are provided so as to be on the upstream side with respect to the rotation direction of the classification rotor from the rotation center side end portion to the outer peripheral side end portion of the classification rotor.
The blade has a bent portion and has a bent portion.
In the cross section when the classification rotor is cut in the direction perpendicular to the rotation axis of the classification rotor.
(I) An angle θ1 formed by a straight line connecting the rotation center of the classification rotor and the rotation center side end of the blade and a straight line connecting the rotation center side end of the blade and the bending portion of the blade. However, it is between 30 ° and 65 °.
(Ii) The distance from the rotation center of the classification rotor to the outer peripheral side end of the blade is L1, the distance from the rotation center of the classification rotor to the rotation center side end of the blade is L2, and the rotation center of the classification rotor. When the distance from the blade to the bent portion of the blade is L3, the following equation is satisfied.
0.65 ≤ (L3-L2) / (L1-L2) ≤ 0.85
(Iii) An angle θ2 formed by a straight line connecting the rotation center side end of the blade and the bent portion of the blade and a straight line connecting the bent portion of the blade and the outer peripheral side end of the blade is formed. 5 ° to 25 °,
(Iv) It relates to a toner rating system characterized in that the sum of the θ1 and the θ2 is 55 ° to 85 °.

In addition, this disclosure is
A method for producing toner, which comprises a classification step of classifying particles to be classified using a toner classifier.
The toner classifier
A toner rating system equipped with a rating rotor.
The classification rotor has a plurality of blades extending from the rotation center side of the classification rotor to the outer peripheral side.
The plurality of blades are arranged at a predetermined distance from each other.
The spacing forms an opening towards the rotation center region of the classification rotor.
The blades are provided so as to be on the upstream side with respect to the rotation direction of the classification rotor from the rotation center side end portion to the outer peripheral side end portion of the classification rotor.
The blade has a bent portion and has a bent portion.
In the cross section when the classification rotor is cut in the direction perpendicular to the rotation axis of the classification rotor.
(I) An angle θ1 formed by a straight line connecting the rotation center of the classification rotor and the rotation center side end of the blade and a straight line connecting the rotation center side end of the blade and the bending portion of the blade. However, it is between 30 ° and 65 °.
(Ii) The distance from the rotation center of the classification rotor to the outer peripheral side end of the blade is L1, the distance from the rotation center of the classification rotor to the rotation center side end of the blade is L2, and the rotation center of the classification rotor. When the distance from the blade to the bent portion of the blade is L3, the following equation is satisfied.
0.65 ≤ (L3-L2) / (L1-L2) ≤ 0.85
(Iii) An angle θ2 formed by a straight line connecting the rotation center side end of the blade and the bent portion of the blade and a straight line connecting the bent portion of the blade and the outer peripheral side end of the blade is formed. 5 ° to 25 °,
(Iv) It relates to a method for producing a toner, which is characterized in that the sum of the θ1 and the θ2 is 55 ° to 85 °.

According to the present disclosure, it is possible to provide a toner classifier and a toner manufacturing method showing a good yield even when a toner having a small particle size is manufactured.

Schematic diagram of the classification rotor Explanatory diagram of air flow between blades Schematic diagram of the toner classifier used in the examples Schematic diagram of the distributed rotor used in the examples Schematic diagram of the guidance means used in the examples Schematic diagram of the liner used in the examples

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

FIG. 1 shows a schematic view of a classification rotor included in a toner classification device. The classification rotor 31
Has a plurality of blades 11 extending from the rotation center side to the outer peripheral side of the classification rotor 31. The plurality of blades 11 are arranged at predetermined intervals from each other. The spacing forms an opening towards the rotation center region of the classification rotor 31. The blade 11 is provided so as to be on the upstream side with respect to the rotation direction of the classification rotor 31 from the rotation center side end portion to the outer peripheral side end portion of the classification rotor 31. The blade 11 has a bent portion.
Further, in the cross section when the classification rotor 31 is cut in the direction perpendicular to the rotation axis of the classification rotor 31.
(I) A straight line connecting the rotation center of the classification rotor 31 and the rotation center side end of the blade 11 and a straight line connecting the rotation center side end of the blade 11 and the bending portion of the blade 11. The angle θ1 formed is 30 ° to 65 °.
(Ii) The distance from the rotation center of the classification rotor 31 to the outer peripheral side end of the blade 11 is L1, the distance from the rotation center of the classification rotor 31 to the rotation center side end of the blade 11 is L2, and the classification. When the distance from the center of rotation of the rotor 31 to the bent portion of the blade 11 is L3, the following equation is satisfied.
0.65 ≤ (L3-L2) / (L1-L2) ≤ 0.85
(Iii) A straight line connecting the rotation center side end of the blade 11 and the bent portion of the blade 11 and a straight line connecting the bent portion of the blade 11 and the outer peripheral side end of the blade 11 are formed. The angle θ2 is 5 ° to 25 °,
(Iv) The total of the θ1 and the θ2 is 55 ° to 85 °.
Reference numeral 12 in FIG. 1 indicates an upper portion of the classification rotor frame, and reference numeral 13 indicates a lower portion of the classification rotor frame. Further, the portion of the blade 11 from the end on the rotation center side to the bent portion may be linear or curved, but is preferably linear as shown in FIG. 1. Furthermore, the portion of the blade 11 from the bent portion to the outer peripheral side end portion may be linear or curved, but is preferably linear as shown in FIG. 1.

When the above-mentioned classification rotor is used, it is possible to provide a toner classification device that exhibits a good yield while sufficiently removing fine powder even with a toner having a small particle size. The present inventors assume this factor as follows.
The centrifugal force acting on an object is indicated by [weight of the object] × [radius of gyration] × [square of angular velocity of rotational motion]. Here, the radius of gyration of the classified particles is considered to be the distance between the center of rotation of the classification rotor and the classified particles. As described above, it is presumed that a vortex is generated between the blades of the classification rotor rotating at high speed when the classification process is performed. Due to the presence of this vortex, an airflow that is strongly drawn inward locally is generated, and it is assumed that particles that should not be removed are also drawn in and removed. When the vortex exists to the inside of the classification rotor, the particles to be classified are drawn toward the inside of the classification rotor and the distance from the center of rotation becomes small, so that the centrifugal force becomes small and the particles return to the outside of the classification rotor. It cannot be done, and as a result, it is removed as fine particles.
The classification rotor is a straight line connecting the rotation center of the classification rotor and the rotation center side end of the blade in the cross section when the classification rotor is cut in the direction perpendicular to the rotation axis of the classification rotor, and the rotation center side end of the blade. The straight line connecting the portion and the bent portion of the blade is arranged so as to form an angle θ1. Further, the blade itself has a bent portion, and the straight line connecting the end on the rotation center side of the blade and the bent portion of the blade and the straight line connecting the bent portion of the blade and the end on the outer peripheral side of the blade form an angle θ2. Because the position of the vortex generated during classification can be outside, and even if particles that should not be removed are drawn in by the vortex, they can return to the outside of the classification rotor because the centrifugal force does not decrease. , It is considered that the yield will improve.

θ1 needs to satisfy 30 to 65 °. When θ1 is less than 30 °, the effect of moving the position where the above-mentioned vortex is generated to the outside is insufficient. When θ1 exceeds 65 °, the distance between the blades of the classification rotor near the inner ends becomes too close, and it becomes difficult for the fine particles to be removed from the classified particles to pass through. θ1 is preferably 35 ° to 65 °, more preferably 45 ° to 65 °.
Further, θ2 needs to satisfy 5 ° to 25 °. When θ2 is less than 5 °, the effect of moving the position where the above-mentioned vortex is generated to the outside is insufficient. When θ2 exceeds 25 °, the angle of the blade itself is too steep, and a second airflow vortex as shown in FIG. 2B is generated near the bent portion, which causes inward. It draws in more particles. θ2 is preferably 10 ° to 25 °, more preferably 15 ° to 20 °.
Further, from the viewpoint that the position where the above-mentioned vortex is generated is sufficiently outside, the total (θ1 + θ2) of θ1 and θ2 needs to be 55 ° to 85 °, preferably 65 ° to 85 °. More preferably, it satisfies 75 ° to 85 °.

Further, the distance from the rotation center of the classification rotor to the outer peripheral side end of the blade is L1, the distance from the rotation center of the classification rotor to the rotation center side end of the blade is L2, and the distance from the rotation center of the classification rotor to the bending portion of the blade. When the distance of is L3, it is necessary to satisfy 0.65 ≦ (L3-L2) / (L1-L2) ≦ 0.85.
When (L3-L2) / (L1-L2) is larger than 0.85, the bent portion is too close to the outer peripheral side of the classification rotor, so that the effect of giving θ2 is not exhibited. Further, when (L3-L2) / (L1-L2) is less than 0.65, the length of the blade from the outer peripheral side end portion to the bent portion of the blade becomes longer, as shown in FIG. 2 (c). A second airflow vortex is generated, which further draws particles that should not be removed toward the center of rotation of the classification rotor.

The radius of the classification rotor is not particularly limited, and can be appropriately set according to the dimensions of the classification device, the amount of particles to be processed, and the like, and can be, for example, 60 mm to 120 mm.
Further, the height of the blades of the classification rotor is not particularly limited, and can be appropriately set according to the dimensions of the classification rotor and the classification device, the amount of particles to be processed, and the like, and can be, for example, 50 mm to 100 mm.
Further, the number of blades of the classification rotor is not particularly limited, and can be appropriately set according to the dimensions of the classification rotor and the classification device, the amount of particles to be processed, and the like, and can be, for example, 20 to 60. Further, the distance between the outer peripheral end portions of the blades arranged in the classification rotor is not particularly limited, and can be appropriately set according to the dimensions of the classification rotor and the classification device, the amount of particles to be processed, and the like.
For example, from the viewpoint of not making the vortex of the airflow generated between the blades arranged in the classification rotor too large, the distance between the blades arranged in the classification rotor and the outer peripheral end of the blades is 25 mm or less. It is preferable to do so. Further, from the viewpoint of suppressing the time required for the treatment from becoming long due to the narrowing of the opening, it is preferably 5 mm or more.

The toner classifying device is not particularly limited as long as it has the classification rotor for removing fine particles in the classified particles. For example, a supply means for supplying the classified particles into the main body of the toner classifying device. It is possible to have a means for collecting the classified material after the classification process. As the particle size of the classified particles becomes smaller, the number of particles per unit weight increases, so that the number of contact points between the particles increases and it becomes easier to form an agglomerate. From the viewpoint that the classification process can proceed while disassembling the agglomerates, the toner classification device includes a cylindrical main body casing as shown in FIG.
With the classification rotor 31
A cylindrical guide means 36 installed with at least a part of the classification rotor covered, and
In order to introduce the classified particles, the classified particle supply means 35 having the classified particle input port 34 and the classified particle input port 34 formed on the side surface of the main body casing,
A fine powder discharge port 39 and a classified particle extraction port 37 formed on the side surface of the main body casing in order to discharge the classified particles from which fine powder has been removed to the outside of the main body casing.
In the main body casing, a dispersion rotor 32 which is a rotating body attached to a central rotating shaft and has a dispersion hammer (for example, a square block) 33 on the side surface of the rotating body on the side surface of the classification rotor 31.
It is preferable to have. The main body casing and the guiding means 36 are not limited to a cylindrical shape, and may have any shape.
Due to the presence of the guiding means 36, an updraft toward the classification rotor 31 is generated in the first space A, and a downdraft toward the dispersion rotor 32 side is generated in the second space B by the dispersion hammer 33. It is considered that the classification treatment can be performed while crushing the agglomerates of the particles to be classified. The dispersion hammer 33 is not limited to a square block as long as it can crush agglomerates of particles to be classified, and can have any shape.
Further, from the viewpoint that the fluidity can be improved by increasing the average circularity of the toner, it is more preferable to have the liner 38 which is fixedly arranged around the dispersion rotor 32 while maintaining an interval. It is preferable that the liner 38 is provided with a groove on the surface facing the dispersion rotor 32.
It is considered that when the particles to be classified collide with a rotating dispersion hammer or a surface facing the dispersion hammer of the liner, the convex portions of the particles to be classified are crushed, and as a result, the circularity is increased. If the fine powder removal efficiency at the time of classification is low, the effect of improving the circularity of the particles may be reduced because the state in which the number of classified particles existing in the casing is large is maintained as compared with the case where the fine powder removal efficiency is high.

The toner classifier can be applied to powder particles obtained by known production methods such as a melt-kneading pulverization method, a suspension polymerization method, an emulsification aggregation method, and a dissolution-suspension method. It can be suitably used in the melt-kneading and pulverizing method from the viewpoint that fine powder is likely to be generated when the particle size is reduced. Hereinafter, the procedure for producing the toner by the melt-kneading pulverization method will be described, but the procedure is not limited to the following procedure.

<Manufacturing method of toner particles>
First, in the raw material mixing step, at least a predetermined amount of the binder resin is weighed and mixed as the toner raw material and mixed. If necessary, a colorant, 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, in the melt-kneading step, the toner raw materials blended and mixed in the raw material mixing step are melt-kneaded to melt the resins and disperse the colorant and the like in the melt-kneaded resin. 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 due to their advantages 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 Bus Co., Ltd., etc. are generally used.
Further, the melt-kneaded product 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 melt-kneaded product obtained in the above cooling step 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. Furthermore, it is crushed by fine crushing using a mechanical crusher such as an innomizer (manufactured by Hosokawa Micron), Cryptron (manufactured by Kawasaki Heavy Industries), a super rotor (manufactured by Nisshin Engineering), and a turbo mill (manufactured by Turbo Industries). To get. In the pulverization step, the toner is pulverized step by step to a predetermined toner particle size.

The pulverized product obtained in the pulverization step is used as the classified particles, and the classified particles are classified using a toner classifying device (classification step) to obtain toner particles.
The obtained toner particles may be used as toner as they are, but in order to impart the functionality required for the toner, if necessary, inorganic fine particles such as silica are added to the toner particles, and then thermal spheroidization treatment or the like is performed. You may go and use it as toner.

In order to cope with the improvement of the transferability of the toner, the average circularity of the toner is preferably 0.955 or more, more preferably 0.960 or more. Further, the average circularity is preferably 0.990 or less from the viewpoint of suppressing cleaning defects.
Further, the weight average particle size of the toner is preferably a small particle size, specifically 3.50 μm to 6.00 μm, from the viewpoint of improving the image quality of the image formed by the toner. More preferably, it is 3.50 μm to 5.00 μm. It is preferable that the weight average particle size of the toner is small, but when it is 3.50 μm or more, it is less likely to slip through the cleaning blade and cause image defects.
Further, the number% of the toner of 3.0 μm or less is preferably 20.0 number% or less, more preferably 15.0 number% or less, and further preferably 10.0 number% or less.

<Raw material for toner>
Next, the raw material of the toner containing at least the binder resin will be described.

<Bundling resin>
As the binder resin, 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, amorphous polyester resin is preferable from the viewpoint of improving low temperature fixability. From the viewpoint of achieving both low temperature fixability and hot offset resistance, a low molecular weight polyester resin and a high molecular weight polyester resin may be used in combination.
Further, from the viewpoint of further improving the low temperature fixability and blocking resistance during storage, a crystalline polyester resin can also be used as a plasticizer.

<Colorant>
The toner raw material can contain a colorant. Examples of the colorant that can be contained in the toner raw material 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 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 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 heating and fixing of the toner may be used. Examples of the release agent generally include low molecular weight polyolefins, silicone waxes, fatty acid amides, ester waxes, carnauba waxes, hydrocarbon waxes and the like.

The methods for measuring various physical properties of toner and raw materials will be described below.
<Measuring method of toner weight average particle size (D4)>
The weight average particle size (D4) of the toner is a precision particle size distribution measuring device "Coulter Counter Multisizer" by the pore electric resistance method equipped with an aperture tube of 100 μm.
3 ”(registered trademark, manufactured by Beckman Coulter) and the attached dedicated software“ Beckman Coulter Multisizer 3 Version 3.51 ”(manufactured by Beckman Coulter) for setting measurement conditions and analyzing measurement data. Measure with 25,000 effective measurement channels, analyze the measurement data, 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.
On 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.
In the dedicated software "Pulse to particle size conversion setting screen", set the bin spacing to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 2 μm or more and 60 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 "flash of the aperture tube" 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 Dispersion 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 for the number% of toner of 3.0 μm or less>
In the step (7) of the method for measuring the weight average particle size (D4) of the toner, the cumulative value of the number% in the particle size region of 3.0 μm or less when the graph / number% is set by the dedicated software is 3. The number% is 0 μm or less.

<Measuring method of average circularity>
The average circularity of the toner is measured by the flow type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) under the measurement and analysis conditions at the time of calibration work.
The specific measurement method is as follows. First, about 20 ml of ion-exchanged water from which impure solids and the like have been removed in advance is placed in a glass container. 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 0.2 ml of the diluted solution is added. Further, about 0.02 g of the measurement sample is added, and the dispersion treatment is performed for 2 minutes using an ultrasonic disperser to prepare a dispersion liquid for measurement. At that time, the dispersion liquid is appropriately cooled so that the temperature is 10 ° C. or higher and 40 ° C. or lower. As the ultrasonic disperser, a desktop ultrasonic cleaner disperser (“VS-150” (manufactured by Vervocrea)) with an oscillation frequency of 50 kHz and an electrical output of 150 W is used, and a predetermined amount of ions are contained in the water tank. Add exchange water, and add about 2 ml of the Contaminone N to this water tank.
The flow-type particle image analyzer equipped with a standard objective lens (10x) was used for the measurement, and the particle sheath "PSE-900A" (manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion liquid adjusted according to the above procedure is introduced into the flow type particle image analyzer, and 3000 toner particles are measured in the HPF measurement mode and the total count mode. Then, the binarization threshold value at the time of particle analysis is set to 85%, the diameter of the analyzed particle is limited to 1.985 μm or more and less than 39.69 μm, and the average circularity of the toner particles is obtained.
In the measurement, automatic focus adjustment is performed using standard latex particles (“RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A” manufactured by Duke Scientific) diluted with ion-exchanged water before the start of the measurement. After that, it is preferable to perform focus adjustment every two hours from the start of measurement.
In the embodiment of the present application, a flow-type particle image analyzer that has been calibrated by Sysmex and has received a calibration certificate issued by Sysmex was used. The measurement was performed under the measurement and analysis conditions at the time of receiving the calibration certification, except that the diameter of the analysis particle was limited to 1.985 μm or more and less than 39.69 μm in equivalent circle diameter.

Hereinafter, the present disclosure will be described in more detail with reference to Examples and Comparative Examples, but the embodiments of the present disclosure are not limited thereto. Hereinafter, the number of copies in Examples and Comparative Examples is based on parts by mass unless otherwise specified.

<Manufacturing example of binder resin>
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 72.0 parts (100 mol% with respect to the total number of moles of polyhydric alcohol)
-Terephthalic acid: 28.0 parts (96 mol% with respect to the total number of moles of polyvalent carboxylic acid)
-Tin 2-ethylhexanoate (esterification catalyst): 0.5 part 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 8 hours while stirring at a temperature of 220 ° 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 anhydride: 1.3 parts (4 mol% with respect to the total number of moles of polyvalent carboxylic acid)
-Tert-Butylcatechol (polymerization inhibitor): 0.1 part After that, 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. Amorphous polyester resin) was obtained. The softening point of the obtained binder resin measured according to ASTM D36-86 was 110 ° C.

<Production example of crushed particles for toner (classified particles)>
・ 90 parts of binder resin ・ 5 parts of Fischer-Tropsch wax (hydrocarbon wax, melting point 90 ° C) ・ C.I. I. Pigment Blue 15:35 Part 5 The above materials are mixed using a Henshell mixer (FM-75 type, manufactured by Mitsui Mine Co., Ltd.) at a rotation speed of 20s- ¹ and a rotation time of 5 min, and then a twin-screw kneader (PCM-). Kneaded with type 30, 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.
A finely crushed product is obtained by crushing the above coarse crushed product under the conditions of a rotor rotation speed of 12000 rpm and a crushing feed of 10 kg / h using a mechanical crusher (Turbo Mill T250-CRS-Rotor shape RS type manufactured by Turbo Industries). rice field. Further, the finely pulverized particles were pulverized under the conditions of a rotor rotation speed of 12000 rpm and a pulverization feed of 10 kg / h to obtain pulverized particles for toner (classified particles). The weight average particle size of the classified particles was 4.40 μm, the number% of 3.0 μm or less was 42.5%, and the average circularity was 0.952.

<Toner classification device>
As the configuration of the toner classifying device, the toner classifying device shown in FIG. 3 was used. The toner classifier is
Cylindrical body casing and
A disk-shaped dispersion rotor 32, which is a rotating body attached to the central rotating shaft and has a plurality of dispersion hammers 33 on the side surface of the rotating body on the classification rotor side, rotates at high speed in the main body casing.
Liners 38, spaced apart around the dispersion rotor 32,
Classification rotor 31, which is a means for classifying particles to be classified,
A fine powder discharge port 39 for discharging and removing fine powder having a predetermined particle size or less selected by the classification rotor 31 and
A cold air inlet (not shown) for introducing cold air from the bottom of the distributed rotor,
A classified particle input port 34 for introducing the classified particles into the main body casing, and a classified particle supply means 35 having the classified particle input port 34.
The classification particle extraction port 37 for discharging the classification particles after the classification treatment, and
It is composed of a cylindrical guide means 36 installed in a state where at least a part of the classification rotor 31 is covered.
By the guiding means 36, the space A of the main body casing in the toner classifying device, the space A in which the airflow is generated in the direction of introducing the particles to be treated into the classification rotor 31, and the rotor 32 and the liner 38 in which the particles to be treated are dispersed. It is partitioned from the space B where the airflow is generated in the direction of introduction.

The height of the space of the main body casing was 300 mm, and the inner diameter was 300 mm. The outer diameter of the dispersion rotor was 285 mm, and as shown in FIG. 4, eight dispersion hammers were mounted on the dispersion rotor, and the length / width / height of the dispersion hammers were set to 30 mm / 20 mm / 20 mm, respectively.
As shown in FIG. 5, the cylindrical guide means is connected to the guide means support member 51, and the guide means support member and the main body casing are connected by a screw or the like so that the guide means can be installed at an arbitrary position. The diameter of the guide means was 250 mm, the height was 230 mm, and the distance between the upper end of the guide means and the upper end of the casing was 20 mm.

<Implementation classification rotor 1>
The implementation classification rotor 1 had the shape shown in FIG. 1, θ1 was 35 °, θ2 was 23 °, L1 was 82 mm, L2 was 57 mm, L3 was 76 mm, and the height of the opening of the classification rotor was 88 mm. The number of feathers was 30.

<Implementation classification rotors 2-8, comparative classification rotors 1-10>
Table 1 summarizes the differences between the implementation classification rotors 2 to 8 and the comparison classification rotors 1 to 10 from the implementation classification rotor 1.

<Liner>
The liner 1 has a plurality of convex portions as shown in FIG. 6 and a concave portion formed between the convex portion and the convex portion, and the shape of the unevenness thereof is triangular, and the convex portion and the convex portion. The repeating distance from the convex portion was 3 mm, the depth of the concave portion was 3.0 mm, and the height of the liner was 50 mm. As the liner 2, a liner 1 having an uneven surface eliminated and a smooth surface was used.

<Example 1 of toner manufacturing method>
Implemented classification rotor 1 and liner 2 are attached to the toner classification device, classification rotor rotation speed 9000 rpm, dispersion rotor rotation speed 5000 rpm, blower air volume 10 m ³ / min, classification cycle 60 sec (classified particle input time 10 sec, classification processing time 30 sec, Toner 1 was obtained by classifying the crushed particles for toner as classified particles for 60 cycles under the condition that the classified product recovery time after the treatment was 20 sec) and the amount of the classified particles charged per cycle was 200 g. Further, toners 2 to 9 and comparative toners 1 to 10 were obtained under the changing conditions shown in Table 2.

<Example 1>
The weight average particle size D4, the number% of 3.0 μm or less, and the average circularity were evaluated by measuring the particle size distribution of the toner 1. Further, the classification yield was determined from the input amount of the particles to be classified (200 g × 60 cycles) and the weight of the obtained toner 1.

<Yield evaluation criteria>
A: Yield 70% or more B: Yield 60% or more, less than 70% C: Yield 50% or more, less than 60% D: Yield less than 50%

<Number% evaluation criteria of 3.0 μm or less>
A: 10.0 Number% or less B: 10.0 Number% or more and 15.0 Number% or less C: 15.0 Number% or less and 20.0 Number% or less D: 20.0 Number% or more

<Evaluation criteria for average circularity>
A: Average circularity 0.960 or more B: Average circularity 0.955 or more and less than 0.960 C: Average circularity less than 0.955

<Examples 2 to 9 and Comparative Examples 1 to 10>
The evaluation was performed in the same manner as in Example 1 except that the toner was changed as shown in Table 3. The evaluation results are shown in Table 3.

11. Feather, 12. Upper part of the classification rotor frame, 13. Classification rotor lower part of frame, 31. Classification rotor, 32. Distributed rotor, 33. Dispersion hammer, 34. Classified particle inlet, 35. Classified particle supply means, 36. Guidance means, 37. Classified product extraction port, 38. Liner, 39. Fine powder outlet, 51. Guidance means support member

Claims (10)

A toner rating system equipped with a rating rotor.
The classification rotor has a plurality of blades extending from the rotation center side of the classification rotor to the outer peripheral side.
The plurality of blades are arranged at a predetermined distance from each other.
The spacing forms an opening towards the rotation center region of the classification rotor.
The blades are provided so as to be on the upstream side with respect to the rotation direction of the classification rotor from the rotation center side end portion to the outer peripheral side end portion of the classification rotor.
The blade has a bent portion and has a bent portion.
In the cross section when the classification rotor is cut in the direction perpendicular to the rotation axis of the classification rotor.
(I) An angle θ1 formed by a straight line connecting the rotation center of the classification rotor and the rotation center side end of the blade and a straight line connecting the rotation center side end of the blade and the bending portion of the blade. However, it is between 30 ° and 65 °.
(Ii) The distance from the rotation center of the classification rotor to the outer peripheral side end of the blade is L1, the distance from the rotation center of the classification rotor to the rotation center side end of the blade is L2, and the rotation center of the classification rotor. When the distance from the blade to the bent portion of the blade is L3, the following equation is satisfied.
0.65 ≤ (L3-L2) / (L1-L2) ≤ 0.85
(Iii) An angle θ2 formed by a straight line connecting the rotation center side end of the blade and the bent portion of the blade and a straight line connecting the bent portion of the blade and the outer peripheral side end of the blade is formed. 5 ° to 25 °,
(Iv) A toner rating system, characterized in that the total of the θ1 and the θ2 is 55 ° to 85 °. The toner classification device according to claim 1, wherein the sum of θ1 and θ2 is 65 ° to 85 °. With the main body casing
Guidance means installed with at least a part of the classification rotor covered,
In order to introduce the classified particles, a classified particle input port formed on the side surface of the main body casing and a classified particle supply means having the classified particle input port,
In order to discharge the classified particles from which fine particles have been removed to the outside of the main body casing, a fine powder discharge port and a classified particle extraction port formed on the side surface of the main body casing,
In the main body casing, a dispersion rotor which is a rotating body attached to a central rotating shaft and has a dispersion hammer on the side surface of the rotating body on the side surface of the classification rotor,
The toner classification device according to claim 1 or 2, further comprising. The toner classification device according to claim 3, further comprising a liner that is fixedly arranged around the dispersion rotor while maintaining a space. The toner classification device according to claim 4, wherein a groove is provided on the surface of the liner facing the dispersion rotor. A method for producing toner, which comprises a classification step of classifying particles to be classified using a toner classifier.
The toner classifier
A toner rating system equipped with a rating rotor.
The classification rotor has a plurality of blades extending from the rotation center side of the classification rotor to the outer peripheral side.
The plurality of blades are arranged at a predetermined distance from each other.
The spacing forms an opening towards the rotation center region of the classification rotor.
The blades are provided so as to be on the upstream side with respect to the rotation direction of the classification rotor from the rotation center side end portion to the outer peripheral side end portion of the classification rotor.
The blade has a bent portion and has a bent portion.
In the cross section when the classification rotor is cut in the direction perpendicular to the rotation axis of the classification rotor.
(I) An angle θ1 formed by a straight line connecting the rotation center of the classification rotor and the rotation center side end of the blade and a straight line connecting the rotation center side end of the blade and the bending portion of the blade. However, it is between 30 ° and 65 °.
(Ii) The distance from the rotation center of the classification rotor to the outer peripheral side end of the blade is L1, the distance from the rotation center of the classification rotor to the rotation center side end of the blade is L2, and the rotation center of the classification rotor. When the distance from the blade to the bent portion of the blade is L3, the following equation is satisfied.
0.65 ≤ (L3-L2) / (L1-L2) ≤ 0.85
(Iii) An angle θ2 formed by a straight line connecting the rotation center side end of the blade and the bent portion of the blade and a straight line connecting the bent portion of the blade and the outer peripheral side end of the blade is formed. 5 ° to 25 °,
(Iv) A method for producing a toner, characterized in that the total of the θ1 and the θ2 is 55 ° to 85 °. The method for producing toner according to claim 6, wherein the sum of θ1 and θ2 is 65 ° to 85 °. The toner classifier
With the main body casing
Guidance means installed with at least a part of the classification rotor covered,
In order to introduce the classified particles, a classified particle input port formed on the side surface of the main body casing and a classified particle supply means having the classified particle input port,
In order to discharge the classified particles from which fine particles have been removed to the outside of the main body casing, a fine powder discharge port and a classified particle extraction port formed on the side surface of the main body casing,
In the main body casing, a dispersion rotor which is a rotating body attached to a central rotating shaft and has a dispersion hammer on the side surface of the rotating body on the side surface of the classification rotor,
The method for producing a toner according to claim 6 or 7, further comprising. The method for producing toner according to claim 8, further comprising a liner that is fixedly arranged around the dispersion rotor while maintaining a space. The method for producing toner according to claim 9, wherein a groove is provided on the surface of the liner facing the dispersion rotor.

Images