JP2007275863A - Cyclone classifier, manufacturing method of toner by classification using cyclone classifier and toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cyclone classifier with simple equipment structure which can finely adjust classified particle size and can catch classified particles with high precision and to attain classification of particles with higher precision by reducing suction of excess particles of large particle size. <P>SOLUTION: The cyclone classifier 1-4 comprises an outer cylinder which has a waistless part and an inverted-cone part vertically connected to an underside of the waistless part and an inner cylinder one end of which is inserted into the outer cylinder. The top end of the inner cylinder which is an exhaust and aspirating opening inserted into the outer cylinder is arranged within height of the inverted-cone part. Further the inner cylinder may be constituted of multiple pipes. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cyclone classifier for classifying and collecting powder having a desired distribution width from powder having a wide particle size distribution width.

  In recent years, there has been an increasing demand for higher functionality for powders, and there has been a demand for powders composed of particles having a small particle size and a narrow particle size distribution range. If the particle size in the powder is distributed over a relatively wide range, it will cause variations in the various functions imparted to the powder particles, so it is possible to collect powder in a more uniform particle size range. It is preferable for high functionality of the powder. For example, in a toner powder used in an electrophotographic apparatus, a wide particle size distribution width is disadvantageous for required performance such as uniform charging and uniform melting.

  Many classification methods are known as means for aligning powders with a uniform particle size. One of the known classification techniques is a means using a cyclone collector. Usually, cyclone collectors are used as solid-gas separation devices. The powder particles that flow into the cyclone collector in the air current are subjected to a centrifugal effect due to the swirling flow in the cyclone collector, and gather toward the inner surface of the outer cylinder of the cyclone collector and gradually fall. It is collected in a container installed at the lower part of the collector outer cylinder. A gas (mostly air) that is much lighter than particles is discharged out of the cyclone collector by exhaust from the inner cylinder in the center of the cyclone collector.

There are many well-known techniques for devising the cyclone collector for solid-gas separation so as to discharge small particles together with the gas and use it as a classifier. The cyclone collector itself is generally used for powder conveyance, etc. By making this equipment function not only as a collector but also as a classifier, there is no need to separately incorporate a classification process. It is a great advantage that capital investment and man-hours can be reduced.
The powder handled here is targeted at a particle size of 1 mm or less, more specifically, a range from several μm to several hundred μm, but the application range of the present invention is not limited to this range. Further, the present invention is applied to all powders, not limited to toner.

  Patent Document 1 describes that particles having a larger diameter can be drawn to the exhaust side by pulling up the inner cylinder tip suction port of the cyclone collector for solid-gas separation from the normal position. The classification by the cyclone collector is achieved by distributing the powder particles in order of increasing particle diameter from the central axis of the outer cylinder of the cyclone classifier toward the outer periphery by the centrifugal force applied to the powder particles by the swirling flow in the cyclone. Pulling up the inner cylinder tip position as in the technique described in Patent Document 1, that is, the centrifugal force due to the swirling flow in the cyclone is not applied to the powder flowing into the cyclone main body from the cyclone inlet, but from the position near the inlet. It is in a state of being sucked, its classification effect is almost the same, and the yield is also deteriorated.

Patent Document 2 describes that the classification accuracy can be made variable by changing the diameter of the cyclone inner cylinder. However, it is difficult to finely adjust the classification particle diameter by this method.
In Patent Document 3, an orifice-shaped partition plate having an opening smaller than the tip opening area of the inner tube is installed at the center on the same axis as the outer tube, and the powder-containing airflow is separated from the tube portion by the partition plate. A technique is described in which the flow rate is increased at the center to be assembled. According to this method, by increasing the flow velocity toward the center of the cylindrical portion, the separation ability based on the particle size of the powder particles is enhanced, but it is difficult to finely adjust the classified particle size.

Japanese Patent Application Laid-Open No. 3-079906 JP 2003-275658 A JP 2004-283720 A

The problem to be solved by the present invention based on the above technical background is to provide a cyclone classifier that can finely adjust the classification particle size and can be collected with high accuracy with a simple equipment structure. .
Furthermore, it is to provide a cyclone classifier capable of reducing the suction of extra large particle diameter particles and enabling more accurate powder classification.

  In order to obtain a high-quality, high-quality toner, the inventors of the present invention dissolve or disperse a toner composition comprising at least a resin and a colorant in an organic solvent, and emulsify the dissolved or dispersed material in an aqueous medium. In the process of collecting colored polymer particles that have been solid-gas separated in a cyclone collector after drying the hydrous cake that has been washed and solid-liquid separated in an air-flow dryer, classification is performed using a cyclone classifier. As a result of intensive studies on conditions for obtaining colored polymer particles having a particle size distribution in a desired narrow range at a high yield, the present invention has been achieved.

  Normally, centrifugal force is applied to the particles by the swirling flow in the cyclone collector, and the particles swirl close to the inner surface of the cyclone outer cylinder, and finally installed under the inverted cone cone part of the cyclone. It falls to the collection part such as a product collection tank. Among the particles on this swirl flow, the centrifugal force applied depends on the size of the particle size, so that the larger particle size is near the inner surface of the cyclone outer cylinder, and the smaller particle size is further inside (the cyclone). In other words, the larger the particle size, the closer to the inner surface of the outer cylinder, the more the particles fall. A comparison of the powders in the swirling flow that are densely distributed in the order of the particle size, but only the small particles located inside (near the center of the cyclone) are sucked into the cyclone. It is possible to remove, that is, classify, only small-sized particles from a powder having a wide target particle size distribution width.

  However, the selection and suction of only small particles from this dense swirling falling powder requires very precise control. In the present invention, by accurately moving the inner cylinder up and down, the gap between the inner surface of the inverted cone cone portion of the cyclone where the dense swirling falling powder exists and the tip of the inner cylinder is freely changed, Particles having a small particle diameter existing near the cyclone center are optionally sucked.

That is, according to the present invention, the following (1) to (10) are provided.
(1) In a cyclone classifier consisting of an outer cylinder with a straight barrel connected to the upper end of an inverted conical cone and an inner cylinder with one end inserted into the outer cylinder, the cyclone classifier is inserted into the outer cylinder as an exhaust suction port. The cyclone classifier is characterized in that the tip of the inner cylinder is disposed within a height range where the inverted conical cone portion exists in the outer cylinder.

(2) The cyclone classifier according to (1), wherein the tip position of the inner cylinder is variable at least within a height range where the inverted conical cone portion exists.
(3) The cyclone classifier according to (1) or (2), wherein an inclination angle of the inverted conical cone portion bus with respect to the perpendicular is 45 ° or less.
(4) The cyclone classifier according to any one of (1) to (3), in which the inner cylinder is formed of multiple tubes.

(5) The cyclone classifier according to (4), wherein at least one of the tip positions of the inner cylinder constituted by the multiple pipes is disposed within a height range where the inverted conical cone portion exists.
(6) The cyclone classifier according to (4) or (5), wherein the inner cylinder constituted by the multiple pipes is variable in the position of each layer tip independently.
(7) Any one of (4) to (6), wherein the powder sucked and discharged from the inner cylinder constituted by the multiple tubes is collected in a collecting container installed independently. It is a cyclone classifier according to the above.

(8) The cyclone classifier according to any one of (1) to (7), wherein the cyclone classifier includes an air dryer.
(9) A method for producing toner, comprising: a step of classifying toner powder using the cyclone classifier according to any one of (1) to (8) above; and a step of collecting the classified toner powder. It is.
(10) Toner collected using the cyclone classifier according to any one of (1) to (8) above.

According to the present invention, a cyclone classifier with high classification accuracy can be provided with a simple equipment structure.
Furthermore, by making the inner cylinder into a multiple tube, powder can be sucked in small portions in several degrees, the amount of extra large particle size suction is reduced, and a cyclone classifier with higher classification accuracy can be obtained. Can be provided.

  Details of the present invention will be described below. In the following description, electrophotographic polymerization toner is mentioned, but the present invention is not limited to polymerization toner and pulverization toner, and is an effective means for all powders.

  In the present invention, in a cyclone classifier comprising an outer cylinder having a straight barrel connected to the upper end of an inverted conical cone and an inner cylinder having one end inserted into the outer cylinder, the inner cylinder inserted into the outer cylinder The exhaust suction port, which is the tip of the cylinder, is arranged within the range of the height where the inverted conical cone portion exists and is variable. At that time, the inclination angle of the inverted conical cone portion bus with respect to the perpendicular becomes important. If the inclination angle is large, even if the vertical movement of the inner cylinder is very small, the fluctuation of the gap between the tip of the inner cylinder and the inner surface of the cone portion increases, and the fluctuation of the swirling diameter of the swirling flow also increases. That is, fine adjustment of the classified particle size becomes difficult. Therefore, the inclination angle is preferably 45 ° or less.

  In addition, when the inner cylinder is made into a multiple pipe and can be made variable independently, for example, in the case of a double pipe, the powder collected in the collection container under the inverted conical cone portion and the powder sucked into the outer pipe of the inner cylinder It is possible to classify the body and the powder sucked into the inner tube of the inner cylinder into three parts. The classified particle diameter in this division can be arbitrarily adjusted by independently changing the multiple tubes of the inner cylinder. Multiple division classification with multiple pipes not only enables classification with higher accuracy than single cylinder inner cylinders, but also collects small particle size powder with the outer inner cylinder, and medium particle size powder with the inner inner cylinder. And collect the powder with large particle size with the drop collector at the bottom, or return the separately collected powder as a product or discard it as small particle size below desired particle size You can do it at will.

As an advantage of the present invention, the solid-gas separation cyclone attached to other production equipment can be used as it is as a classification cyclone, and at that time, a new power source is not required and it is reasonable. In the present invention, the examination was performed on the assumption that the cyclone for powder recovery after airflow drying is diverted to have a classification ability. FIG. 5 shows a schematic arrangement of an actual air dryer and a cyclone, and FIG. 6 shows a schematic diagram of the main body of the air dryer. As shown in FIG. 5, the airflow emitted from the air supply fan (3-1) is heated by the heater (3-2) and supplied as dry air to the airflow dryer main body (3-3). At the same time, the water-containing cake is supplied from the feeder (3-4) to the main body of the air dryer. The colored polymer particles that have been sufficiently crushed and dried are collected by the cyclone (3-5) through the discharge port and collected in the tank (3-6). In FIG. 5, (3-7) is a bag filter, and (3-8) is an exhaust fan. The present invention has been devised to give the collection cyclone a classification function.
In FIG. 6, (4-1) is a dryer main body, (4-2) is a wet cake inlet, (4-3) is a dry air supply port, and (4-4) is a colored polymer particle and dried after drying. Wind outlet. In this air dryer, the heated drying air is supplied from the dry air supply port (4-3) into the dryer main body (4-1). The drying wind circulates in the dryer main body (4-1) while drying the hydrous cake continuously fed from the hydrous cake inlet (4-2), and discharges together with the colored polymer particles after drying. It is discharged continuously to (4-4).

  Hereinafter, the production process of the present invention and colored polymer particles used in the present invention will be described. However, the present invention is not limited to the colored polymer particles described below, but various other types and particle sizes. It is also effective for other particles. Hereinafter, a part shows a weight part.

(Raw material adjustment)
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30: manufactured by Sanyo Chemical Industries), 138 parts of styrene, 138 parts of methacrylic acid, When 1 part of ammonium persulfate was charged and stirred at 400 rpm for 15 minutes, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and an aqueous dispersion of a vinyl resin (a copolymer of a sodium salt of a styrene-methacrylic acid-methacrylic acid etherene oxide adduct sulfate). This is referred to as “fine particle dispersion”.

Further, 83 parts of [fine particle dispersion] were mixed with 990 parts of water, 37 parts of a 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries), and 90 parts of ethyl acetate. Got.
This is referred to as [aqueous phase].

In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts terephthalic acid, 46 parts adipic acid and dibutyl Add 2 parts of tin oxide, react for 8 hours at 230 ° C. under normal pressure, and further react for 5 hours under reduced pressure of 10-15 mmHg, then add 44 parts of trimellitic anhydride to the reaction vessel and react for 2 hours at 180 ° C. under normal pressure. As a result, [low molecular polyester] was obtained.
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride Then, 2 parts of dibutyltin oxide was added, reacted at 230 ° C. under normal pressure for 8 hours, and further reacted at reduced pressure of 10 to 15 mmHg for 5 hours to obtain an [intermediate polyester].
Next, 410 parts of [intermediate polyester], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate were placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Phase].

  In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound].

1200 parts of water, 540 parts of carbon black (manufactured by Printex 35 Dexa) [DBP oil absorption = 42 ml / 100 mg, pH = 9.5], 1200 parts of polyester resin are added,
The mixture was mixed with a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), and the mixture was kneaded at 150 ° C. for 30 minutes using two rolls, then cooled by rolling and pulverized with a pulverizer to obtain a [masterbatch].

  A container equipped with a stir bar and a thermometer was charged with 378 parts of [low molecular polyester], 110 parts of Carnauba WAX, 22 parts of CCA (salicylic acid metal complex E-84: Orient Chemical Co., Ltd.), and 947 parts of ethyl acetate. The temperature was raised to 80 ° C. and maintained at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour. Next, 500 parts of [Masterbatch] and 500 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution].

  [Raw material solution] Transfer 1324 parts to a container and use a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.) to fill a liquid feed speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 80% by volume of 0.5 mm zirconia beads. Carbon black and WAX were dispersed under conditions of 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester] was added, and one pass was performed with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion].

  [Pigment / WAX dispersion] 664 parts and [ketimine compound] 5.9 parts are put in a container and mixed well with a disper to obtain [B oil phase].

(Emulsification process)
[A oil phase] and [B oil phase] are fed with a feed pump and mixed through a static mixer (manufactured by Noritake Co.). The liquid feed amount is adjusted so that [B oil phase] becomes 60.4 parts with respect to [A oil phase] 7.4 parts. Here, the well-mixed and uniform mixture (referred to as [oil phase]) is combined with 101.6 parts of [aqueous phase] fed separately by a liquid feed pump, and the continuous emulsifier pipeline homomixer [ Giving a great shearing force at 8400 rpm and emulsifying with Special Machine Chemical Co., Ltd.]. At this time, it becomes [Slurry liquid A] in which minute [oil phase] droplets that become colored polymer particles are present in the [aqueous phase] medium.

(Solvent removal process, aging process)
[Slurry liquid A] containing an organic solvent is put into a container in which a stirrer and a thermometer are set, and after removing the solvent at 40 ° C. for 8 hours, aging is performed at 60 ° C. for 8 hours to obtain [slurry liquid B]. It was.

(Washing process, solid-liquid separation process)
[Slurry liquid B] 100 parts were solid-liquid separated with a filter press and dehydrated with a pressing pressure of 0.4 MPa to obtain [Hydrohydrate cake A].
To 100 parts of this [hydrated cake A], 200 parts of ion-exchanged water was added and dispersed uniformly with a TK homomixer (rotation speed: 6,000 rpm for 30 minutes) to obtain [Dispersed slurry liquid A].
100 parts of [dispersed slurry liquid A] was subjected to solid-liquid separation using a siphon pillar type centrefuge with a centrifugal effect of 1000 G to obtain [hydrous cake B].

(Drying process)
[Water-containing cake B] was dried with a flash dryer. [Water-containing cake B] had a water content of 25% by weight.
This time, MODEL4-THERMAJET FLASH DRYER (manufactured by FLUID ENERGY) was used as the air dryer. In the present invention, a cyclone for classification can be obtained by modifying the cyclone for collecting the colored polymer particles discharged from the air dryer. The present invention is not limited to the air dryer used this time, but can be used for various air dryers in which any powder to be classified and any gas are mixed and discharged. Examples of airflow dryers include flash jet dryers (manufactured by Seishin Enterprise Co., Ltd.), flash dryers (manufactured by Hosokawa Micron Corp.), clean flashes (manufactured by Tsukishima Kikai Co., Ltd.), THERMA JET FLASH DRYER (FLUID ENERG
Y).
This time, the drying conditions of the air dryer were set to an air volume of 10 m ³ / min, an inlet temperature of 65 ° C., and an outlet temperature of 33 ° C. As a result of airflow drying under these conditions, the drying treatment speed was 0.5 kg / min. The moisture content after air-drying was 0.9% by weight.

<Example 1>
The colored polymer particles that had undergone the drying step were classified using an experimental cyclone classifier. A schematic diagram of the cyclone classifier used and its associated facilities is shown in FIG. Since air is sucked by the exhaust fan (1-8), the small particle size particles sucked together with the exhaust from the cyclone classifier (1-4) using the present invention and the inner cylinder of the cyclone classifier are collected. A swirling flow is generated in the cyclone collector (1-6) for this purpose. First, the colored polymer particles are quantitatively discharged continuously from the powder feeder (1-1) into the tray (1-3). The colored polymer particles discharged into the tray (1-3) are taken by the suction of the exhaust fan (1-8) and the air flow from the powder feed air (1-2), and are then placed in the cyclone classifier (1-4). Sent to. The colored polymer particles classified into the desired particle size and the particle size distribution width by the swirling flow in the cyclone classifier (1-4) are dropped and collected in the desired particle size particle collecting container (1-5). Colored polymer particles having a particle size smaller than the desired particle size are discharged from the inner cylinder of the cyclone classifier (1-4) and enter the cyclone collector (1-6). All colored polymer particles having a particle size smaller than the desired particle size are collected by the swirling flow of the cyclone collector (1-6) and fall into the small particle size particle collecting container (1-7).

  A schematic diagram of the cyclone classifier used in Example 1 is shown in FIG. The colored polymer particle group having a wide particle size distribution width flowing from the cyclone introduction part (2-1) receives the centrifugal force in the cyclone outer cylinder straight part (2-3) by the swirling flow in the cyclone and gradually becomes a cyclone. It descends along the outer cylinder inverted conical cone part (2-4). Small particles gathered near the cyclone center (swivel center) in the swirling powder by the centrifugal force received by the cyclone outer cylinder straight body part (2-3) and the cyclone outer cylinder inverted conical cone part (2-4). The particle size particles are discharged from the cyclone classifier using the present invention together with the exhaust flow from the cyclone inner cylinder (2-2).

This time, the same colored polymer particles were used in each of the examples and comparative examples.
The colored polymer particles used have a volume average particle diameter Dv = 5.8 μm, and Dv / Dn obtained by dividing the volume average particle diameter Dv [μm] by the number average particle diameter Dn [μm] indicates the particle size distribution width of the powder. , The closer the Dv / Dn is to 1.00, the narrower the particle size distribution width and the more uniform the particle size. The colored polymer particles used were Dv / Dn = 1.18. Further, the small particle size particles to be removed this time have a particle size of 4 μm, and the content of the particle size of 4 μm or less in the colored polymer particle powder was 14.6% by number.

The conditions of the cyclone in which the experiment was conducted were an exhaust fan air flow rate of 270 m ³ / h, a colored polymer particle feed rate of 8.7 kg / h, a cyclone outer cylinder inner diameter of 155 mm, a cyclone outer cylinder straight body length of 300 mm, a cyclone outer cylinder Reverse cone cone part length (2-4: perpendicular direction length) 200 mm, inclination angle (2-γ) 15 formed by the bus (2-α) and the perpendicular line (2-β) of the cyclone outer cylinder inverse cone cone part The inner cylinder inner diameter was 55 mm.
In Example 1, the length of the inner cylinder (2-2) in the cyclone was 350 mm from the uppermost surface (2-5) of the cyclone outer cylinder.

<Example 2>
In the present Example 2, the length of the inner cylinder (2-2) in the cyclone was 400 mm from the uppermost surface (2-5) of the cyclone outer cylinder. Other conditions were the same as in Example 1.

<Example 3>
In the present Example 3, the length of the inner cylinder (2-2) in the cyclone was 450 mm from the uppermost surface (2-5) of the cyclone outer cylinder. Other conditions were the same as in Example 1.

<Example 4>
In the present Example 4, the length of the inner cylinder (2-2) in the cyclone was 460 mm from the uppermost surface (2-5) of the cyclone outer cylinder. Other conditions were the same as in Example 1.

<Example 5>
In the fifth embodiment, the inclination angle (2-γ) formed between the generatrix (2-α) and the perpendicular line (2-β) of the cyclone outer cylinder inverted conical cone portion (2-4) is 45 °, and the inner cylinder The internal length of the cyclone (2-2) was 310 mm from the uppermost surface (2-5) of the cyclone outer cylinder. Other conditions were the same as in Example 1.

<Example 6>
In the sixth embodiment, the inclination angle (2-γ) formed by the bus (2-α) and the perpendicular (2-β) of the cyclone outer cylinder inverted conical cone portion (2-4) is 45 °, and the inner cylinder The length in the cyclone (2-2) was set to a position 320 mm from the uppermost surface (2-5) of the cyclone outer cylinder. Other conditions were the same as in Example 1.

<Example 7>
In this Example 7, the cyclone inner cylinder was a double pipe (FIG. 3). Next, as shown in FIG. 4, the small particle size particles discharged together with the exhaust gas from the outer tube of the inner tube double tube are captured by the cyclone collector (1-6a), and the small particle size particle collection container (1 Collected in -7a). The small particle diameter particle | grains discharged | emitted with exhaust_gas | exhaustion from an inner side pipe | tube among inner cylinder double pipes are capture | acquired by the cyclone collector (1-6b), and are collected in a small particle diameter particle | grain collection container (1-7b).

  In the seventh embodiment, as shown in FIG. 3, the inner length of the inner cylinder outer tube (2-2a) is set to 420 mm from the uppermost surface (2-5) of the cyclone outer tube, and the inner cylinder inner tube (2-2b). ) In the cyclone was set at a position of 460 mm from the uppermost surface (2-5) of the cyclone outer cylinder. Further, the inner diameter of the inner tube outer tube (2-2a) of the double tube is 70 mm, the inner tube inner diameter of the inner tube inner tube (2-2b) is 55 mm, and the cyclone collector (1-6a). , (1-6b) has an inner cylinder inner diameter of 55 mm and an inner cylinder length of 130 mm. Other conditions were the same as in Example 1.

<Example 8>
In the present Example 8, the cyclone inner cylinder was made into a double pipe like Example 7. As shown in FIG. 4, the small particle diameter particle | grains discharged | emitted with exhaust_gas | exhaustion from an outer side pipe | tube among inner cylinder double pipes are capture | acquired by the cyclone collector (1-6a), and a small particle diameter particle collection container (1- 7a). The small particle diameter particle | grains discharged | emitted with exhaust_gas | exhaustion from an inner side pipe | tube among inner cylinder double pipes are capture | acquired by the cyclone collector (1-6b), and are collected in a small particle diameter particle | grain collection container (1-7b).

  In the eighth embodiment, the inner length of the inner cylinder outer tube (2-2a) is 440 mm from the uppermost surface (2-5) of the cyclone outer tube, and the inner length of the inner cylinder inner tube (2-2b) is cyclone. Was set at a position of 460 mm from the uppermost surface (2-5) of the cyclone outer cylinder. Other conditions were the same as in Example 1.

<Comparative Example 1>
In this comparative example 1, the length of the inner cylinder (2-2) in the cyclone was 150 mm from the uppermost surface (2-5) of the cyclone outer cylinder. At this time, the tip suction port of the cyclone inner cylinder (2-2) is positioned at the height within the existence range of the cyclone outer cylinder straight body (2-3). Other conditions were the same as in Example 1.

<Comparative example 2>
In Comparative Example 2, the inner length of the inner cylinder (2-2) was set to a position 250 mm from the uppermost surface (2-5) of the cyclone outer cylinder. At this time, the tip suction port of the cyclone inner cylinder (2-2) is positioned at the height within the existence range of the cyclone outer cylinder straight body (2-3). Other conditions were the same as in Example 1.

[Evaluation methods]
<Particle size>
The colored polymer particles in each of the above examples and comparative examples were measured for particle size using a Coulter counter method.
As an apparatus for measuring the particle size distribution of toner particles by the Coulter counter method, there are Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. Here, an about 1% NaCl aqueous solution is prepared using first grade sodium chloride as an electrolytic solution. For example, ISOTON-II (manufactured by Coulter, Inc.) can be used. Further, 2 to 20 mg of a measurement sample is added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the measuring device is used to measure the volume and number of toner particles or toner using a 100 μm aperture as an aperture. Volume distribution and number distribution are calculated. From the obtained distribution, the volume average particle diameter (Dv) and the number average particle diameter (Dn) of the toner can be obtained.
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 .35 to less than 8.00 μm; 8.00 to less than 10.08 μm; 10.08 to less than 12.70 μm; 12.70 to less than 16.00 μm; 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm.
“Yield” in Table 1 indicates the colored polymer particle powder collected in the collection container (1-5) after the cyclone classification using the total weight value of the colored polymer particle powder charged into the cyclone classifier. It is a value obtained by dividing the body weight value, and can be rephrased as the weight ratio of the powder recovered in the collection container (1-5) out of the total charged amount of the colored polymer particle powder.
Table 1 shows the results of evaluating examples and comparative examples using the above evaluation methods.

  As shown in Table 1, in Comparative Examples 1 and 2 in which the present invention is not used, a suction port at the tip of the inner cylinder exists in the cyclone outer cylinder straight body part, and the inner cylinder is moved up and down within the range of the outer cylinder straight cylinder part. Even if it makes it, the classification effect is very small. In Examples 1 to 4 using the present invention, as the inner cylinder tip position is lowered, the content of fine powder of 4 μm or less is reduced, and the particle size distribution range indicated by Dv / Dn is also improved.

  In Example 6 in which the inclination angle formed between the generatrix of the cyclone outer cylinder inverted conical cone part (2-4) and the perpendicular is 45 °, the inner cylinder tip comes into contact with the inner surface of the outer cylinder inverted cone cone part. The tip of the inner cylinder was positioned at a position about 30 mm higher than the height. The condition in which the tip of the inner cylinder is positioned 10 mm above is Example 5. Similarly, the position where the tip of the inner cylinder is about 30 mm higher than the height at which the tip of the inner cylinder comes into contact with the inner surface of the outer cylinder inverted conical cone part at an inclination angle of 15 ° formed by the generatrix and the vertical line of the cyclone outer cylinder inverted cone cone part is shown in FIG. 4. The condition in which the tip of the inner cylinder is positioned 10 mm above is Example 3. In Example 6, compared to Example 5, particles having a desired particle diameter are sucked together with the small particle diameter particles, and the classification accuracy is deteriorated. Compared to Examples 3 and 4 in which the outer cylinder inverted conical cone portion inclination angle is 15 °, Examples 5 and 6 are inferior in precision control at the same inner cylinder tip position movement width. As a result, when the inclination angle between the generatrix and the vertical line of the cyclone outer cylinder inverted conical cone portion is greater than 45 °, the inner cylinder tip position accuracy required for high accuracy classification is very strict, and high accuracy classification is required. This is not preferable as the condition.

  In the single-pipe tube, the small particle size particles were excluded by one-stage suction, and in Example 7, the inner cylinder was made into a double tube, so that the opportunity for suction of the small particle size particles could be divided twice. Only small particle size particles can be eliminated with higher accuracy. Furthermore, in Example 8, in the double tube inner cylinder that is variable in length, as a result of changing the length of the outer tube (2-2a) in the cyclone, a larger amount of small particle size particles are discharged than in Example 7, The classification particle size can be controlled arbitrarily by changing the length of the multi-tube in the cyclone.

It is arrangement | positioning schematic of the cyclone classifier and incidental equipment which were used for this invention. It is the schematic of the cyclone classifier used for this invention. It is the schematic of the cyclone classifier (inner cylinder double pipe type) used for this invention. It is an arrangement schematic diagram of a cyclone classifier (inner cylinder double pipe type) and ancillary equipment used in the present invention. It is an arrangement schematic diagram of a cyclone classifier used in the present invention, an air dryer, and incidental equipment. It is the schematic of the air dryer shown in FIG.

Explanation of symbols

1-1 Powder feeder 1-2 Pelletizing air 1-3 Saucepan
1-4 Cyclone classifier 1-5 Desired particle size collection container 1-6 Cyclone collector (1-6a for double pipe inner cylinder outer pipe, 1-6b for double pipe inner cylinder inner pipe)
1-7 Small particle collection container (1-7a for double tube inner tube outer tube, 1-7b for double tube inner tube inner tube)
1-8 Exhaust fan

2-1 Cyclone introduction part 2-2 Cyclone inner cylinder (2-2a Double pipe inner cylinder outer pipe, 2-2b Double pipe inner cylinder inner pipe)
2-3 Cyclone outer cylinder straight barrel part 2-4 Cyclone outer cylinder inverted conical cone part 2-5 Cyclone outer cylinder top surface position 2-α Cyclone outer cylinder inverted conical cone part bus 2-β Cyclone outer cylinder inverted cone shape Cone section perpendicular 2-γ Cyclone outer cylinder inverted cone cone section inclination angle

3-1 Air supply fan 3-2 Heater 3-3 Airflow dryer main body 3-4 Supply machine 3-5 Cyclone 3-6 Tank 3-7 Bag filter 3-8 Exhaust fan

4-1 Dryer body 4-2 Water-containing cake inlet 4-3 Dry air supply port
4-4 Colored polymer particles after drying and outlet for drying air

Claims (10)

  In a cyclone classifier consisting of an outer cylinder with a straight barrel connected to the upper end of an inverted conical cone and an inner cylinder with one end inserted into the outer cylinder, the inner cylinder inserted into the outer cylinder as an exhaust suction port A cyclone classifier characterized in that the tip is disposed within a height range where an inverted conical cone portion exists in the outer cylinder.   2. The cyclone classifier according to claim 1, wherein the tip position of the inner cylinder is variable at least within a height range where the inverted conical cone portion exists.   The cyclone classifier according to claim 1 or 2, wherein an inclination angle of the inverted conical cone portion bus with respect to the perpendicular is 45 ° or less.   The cyclone classifier according to any one of claims 1 to 3, wherein the inner cylinder is formed of a multi-layer structure with multiple tubes.   5. The cyclone classifier according to claim 4, wherein at least one of the tip positions of the inner cylinder constituted by the multiple pipes is disposed within a height range where the inverted conical cone portion exists.   The cyclone classifier according to claim 4 or 5, wherein the inner cylinder constituted by the multiple pipes is variable in the position of the tip of each layer independently.   The cyclone according to any one of claims 4 to 6, wherein the powder sucked and discharged from the inner cylinder constituted by the multiple pipes is collected in collection containers installed independently. Classifier.   The cyclone classifier according to any one of claims 1 to 7, wherein the cyclone classifier includes an airflow dryer.   9. A method for producing toner, comprising: a step of classifying toner powder using the cyclone classifier according to claim 1; and a step of collecting the classified toner powder.   A toner, which is a powder collected using the cyclone classifier according to claim 1.

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