JPH0929176A - Airflow type classifier and toner manufacturing method - Google Patents

Abstract

(57) Abstract: An object of the present invention is to classify powder having a fine particle size distribution, which is capable of highly accurate classification, and an airflow classifying apparatus, and a toner manufacturing method using the apparatus. To provide. According to the present invention, a powder raw material supplied from a raw material supply nozzle is supplied to at least a coarse powder group and a medium powder group by a Coanda effect in a classification area formed by at least a Coanda block and a plurality of classification edges. And an air stream classifier for classifying into a fine powder group, a raw material supply nozzle is provided on an upper surface of the air stream type classification apparatus, and a Coanda block is provided on a side surface side of the raw material supply nozzle. The present invention relates to an air flow type classification device having a powder raw material supply unit for supplying a powder raw material to an end and a high pressure air introduction unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airflow classifying apparatus for classifying powder by utilizing the Coanda effect and a method for producing a toner for developing an electrostatic charge image using the apparatus. Particularly, in order to efficiently classify a powder containing 50% by number or more of particles having a weight average particle diameter of 20 μm or less, the present invention carries the powder on an air stream and carries out the Coanda effect and each particle in the powder. The present invention relates to an airflow type classifying device for classifying particles having a predetermined particle size based on a difference in inertial force, centrifugal force, etc. according to the particle size, and a method for producing a toner using the device.

[0002]

2. Description of the Related Art An air flow type classifying apparatus of various methods for classifying powder has been proposed. Among them, there are classifiers that use rotary blades and classifiers that have no moving parts. Among them, there are a fixed wall centrifugal classifier and an inertial force classifier as classifiers having no moving parts, but Lof as a classifier utilizing inertial force.
fier. F. and K. Maly: Symp on
An elbow jet classifier described in Powder Techn D2 (1981) and commercialized by Nippon Steel Mining Co., Ltd., Okuda. S. and Yasukun
i. J. Proc. Inter. Symposium
on Powder Techn '81, 771 (1
The classifier exemplified in 981) has been proposed as an inertial force classifier capable of classifying in the fine powder region.

These air flow type classifiers are shown in FIGS.
As shown in, the powder is jetted into the classifying area at high speed from the supply nozzle 16 having an opening in the classifying area of the classifying chamber, and is coarsened by the centrifugal force of the curved airflow flowing along the Coanda block 26 in the classifying chamber. The coarse powder, the medium powder, and the fine powder are classified by the finely divided edges 117 and 118 of the powder, the medium powder, and the fine powder.

However, in the conventional classifying device 101, the finely pulverized raw material is introduced from the raw material supply nozzle 16 and the powder or granular material flowing inside the pyramidal cylinder tends to flow straight in parallel with the tube wall with a propulsive force. The raw material supply nozzle 1
When the raw material is introduced from above in 6, the raw material is roughly divided into an upper flow and a lower flow, and the upper flow contains a large amount of light fine powder, and the lower flow contains a large amount of heavy coarse powder. Flow independently, so different trajectories are drawn depending on the site of introduction into the classification chamber, and the coarse powder disturbs the fine powder trajectory, limiting the improvement of classification accuracy, and reducing the coarse powder of 20 μm or more. The accuracy tended to decrease in the classification of powders containing a lot of powder. Further, generally, the classification edge blocks 124 and 125 are fixed to the main body of the classifier, and by adjusting the tip positions of the classification edges 117 and 118, and adjusting the flow rate of the airflow for classification accordingly,
The classification point (that is, the size of the particle that becomes the boundary of classification) is set to a desired value. Further, the tip position of the classification edge corresponding to the specific gravity of the powder and the predetermined classification point is detected and moved, and the flow rate is controlled to a predetermined flow rate accordingly. As described above, if only the tip positions of the classification edges 117 and 118 are adjusted, the turbulence of the air flow easily occurs near the tip ends of the edges depending on the angle, and as a result, accurate classification may not be obtained. In this case, particles having a size that should be uniform may be mixed with particles having a size that should enter another particle group. Also,
Even if you want to change the classification point, you cannot change the position of the classification edge along the direction of the air flow even if you change the tip position of the classification edge and control it so that the flow rate becomes a predetermined value accordingly. Not only does it take time to adjust the value to a predetermined value, but there is a problem to be improved such that the classification accuracy is likely to decrease. In particular, in the classification for producing the toner for developing an electrostatic charge image used in a copying machine, a printer, etc., such a problem was likely to become apparent.

In general, toners are required to have many different properties, and in order to meet such requirements, the characteristics of the toners are often influenced by the manufacturing method as well as the raw materials used. In the classifying process for producing toner, it is required to efficiently and stably produce high-quality toner at low cost.

Generally, as the binder resin used in the toner, a resin having a low melting point, a low softening point or a low glass transition point is used, and a powder containing such a resin is used in a classification range. When introduced and classified, adhesion or fusion is likely to occur in the classifier.

In recent years, for example, as a measure for energy saving of a copying machine, a soft binder such as wax is used as a binder resin for fixing to a recording material such as a transfer material by pressure, or in the case of heat fixing. In order to increase the fixing speed or to reduce the power consumption required for fixing and to fix at a low temperature even if there is any, a binder resin having a low glass transition point or a low softening point has been used.

Further, in order to improve the image quality in copying machines and printers, the toner particles tend to be gradually miniaturized. In general, as the substance becomes finer, the action of interparticle force increases, but the same applies to resin particles and toner particles, and when the size is small, the cohesiveness between particles increases.

When an external force such as an impact force or a frictional force acts on such an agglomerate, in the raw material supply system shown in FIG. 9, the particles are easily fused near the raw material introduction port and the high pressure air supply port,
Further, it is easy to fuse even in the classifying device. In particular, fusion is likely to occur at the throat portion of the raw material introduction port and the tip of the classification edge, and when such a phenomenon occurs, the classification accuracy decreases, and the classification device does not operate in a stable state.
It may be difficult to obtain a high-quality classified product for a long period of time.

In view of the above points, there has been a strong demand for an air flow type classifying apparatus which can classify resin fine powder such as toner in a stable, efficient and accurate manner.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an airflow type classification apparatus which solves the above problems and a method for producing a toner using the apparatus.

An object of the present invention is to use an air flow type classification device and a device therefor, which can perform more accurate classification by setting an accurate classification point and can efficiently generate a powder having a fine particle size distribution. To provide a method for producing a toner.

Another object of the present invention is to provide a toner using the airflow type classifying apparatus and the apparatus, which are less likely to cause fusion and the like and do not cause a change in the classifying point in the apparatus and can perform stable classification. It is to provide a method of manufacturing.

It is a further object of the present invention to provide an air flow type classification device which can change the classification point to a large extent and a method for producing toner using the device.

A further object of the present invention is to provide an airflow type classification device which can change the classification point in a short time, and a method for producing toner using the device.

[0016]

According to the present invention, a powder raw material supplied from a raw material supply nozzle is provided at least in a coarse powder group by a Coanda effect in a classification area formed by at least a Coanda block and a plurality of classification edges. In an airflow classifier for classifying into a medium powder group and a fine powder group, a raw material supply nozzle is provided on an upper surface of the airflow type classification apparatus, and a Coanda block is provided on a side surface side of the raw material supply nozzle, The present invention relates to an air current classifying device, which has a powder raw material supply unit for supplying a powder raw material to a rear end portion of the raw material supply nozzle and a high-pressure air introduction pipe.

The present invention further provides a method for classifying colored resin particles containing at least a binder resin and a colorant with an airflow classifier utilizing the Coanda effect, and producing a toner from the classified powder. The colored resin particles are supplied to the raw material supply nozzle from the rear end of the raw material supply nozzle installed on the upper surface of the type classification device together with the high pressure air from the high pressure air introduction pipe through the powder raw material supply unit, and the raw material supply is performed. In the classification area formed by the Coanda block and a plurality of classification edges installed on the side surface of the nozzle, the colored resin particles supplied from the raw material supply nozzle are at least a coarse powder group, a medium powder group and a Coanda effect due to the Coanda effect. The present invention relates to a method for producing a toner, which comprises classifying into a fine powder group and producing a toner from the classified medium powder group.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In the airflow classifying apparatus of the present invention and the method for producing a toner using the apparatus, the raw material supply is preferably installed at an angle of θ = 45 ° or less with respect to the vertical direction. The rear end of the nozzle is equipped with a high-pressure air introduction pipe and a powder raw material introduction nozzle, and the raw material powder is supplied from a raw material supply port provided above the powder raw material introduction nozzle. The powder material is radiated from the lower part of the raw material introduction port from the outer circumference of the high-pressure air introduction pipe, is accelerated by the high-pressure air and is well dispersed, and the well-dispersed powder raw material can be supplied to the raw material supply nozzle. When the shape of the classification area is changed, the classification area is expanded, the classification point can be changed significantly, and the classification point can be adjusted with high accuracy without generating airflow turbulence near the end of the classification edge. It is. The principle of suction and discharge of the powder raw material in the powder raw material supply unit is based on the ejector effect by the expansion and decompression of the high pressure air from the high pressure air introduction pipe in the powder raw material supply nozzle.

[0019]

The present invention will be described in more detail below with reference to the accompanying drawings.

FIG. 1 shows an example of an airflow classifier according to the present invention.
An apparatus of the type shown in (cross-sectional view) and FIGS. 2 and 3 (perspective view) is illustrated as a specific example.

1 and 2 and 3, the side wall 22 is shown.
And 23 form part of the classification chamber and the classification edge blocks 24 and 25 comprise the classification edges 17 and 18. The classification edges 17 and 18 are rotatable about the shafts 17a and 18a, and the classification edge tip position can be changed by rotating the classification edge. Each classifying edge block 24 and 25 can be slid up and down, and the knife edge type classifying edges 17 and 18 are slid up and down accordingly. With the classification edges 17 and 18, the classification chamber 32
The classification zone is divided into three parts.

Raw material supply port 40 for introducing raw material powder
Is provided at the rearmost end of the raw material supply nozzle 16, a high pressure air introduction pipe 41 and a powder raw material introduction nozzle 42 having a powder raw material supply section are provided at the rear end of the raw material supply nozzle 16, and the classification chamber 32 is provided. The raw material supply nozzle 16 having an opening at the side wall 22
A Coanda block 26, which is provided on the right side of FIG. 1 and draws an elliptical arc in the extension direction of the right tangent line of the raw material supply nozzle 16. The left block 27 of the classification chamber 32 is provided with a knife-edge type air intake edge 19 toward the left side of the classification chamber 32.
Further, on the left side of the classification chamber 32, inlet pipes 14 and 15 that open to the classification chamber 32 are provided. Also, the intake pipe 1
4 and 15 are provided with a first gas introduction adjusting means 20 and a second gas introduction adjusting means 21, such as a damper, a static pressure gauge 28 and a static pressure gauge 29.

Classification edges 17 and 18 and intake edge 1
The position of 9 is adjusted depending on the type of powder as the raw material to be classified and the desired particle size.

Further, on the right side of the classification chamber 32, the discharge ports 11 and 1 opened in the classification chamber in correspondence with respective fractionation areas.
2 and 13, and the outlets 11, 12 and 13 are connected to a communicating means such as a pipe, and each of them may be provided with an opening / closing means such as a valve means.

The raw material supply nozzle 16 is composed of a right-angled cylinder portion and a pyramidal cylinder portion, and the ratio of the inner diameter of the right-angled cylinder portion to the inner diameter of the narrowest part of the pyramidal cylinder portion is 20: 1 to 1: 1, preferably 10: 1.
To 2: 1 results in good introduction rates.

The classification operation in the multi-division classification area configured as described above is performed, for example, as follows. That is,
The inside of the classification chamber is decompressed through at least one of the discharge ports 11, 12, and 13, and high-pressure air in the raw material supply nozzle 16 having an opening in the classification chamber and the air flow flowing by the decompression, preferably a flow rate of 50 to 300 m. The powder is jetted into the classification chamber through the raw material supply nozzle 16 at a speed of / sec.

The particles in the powder introduced into the classifying chamber are curved due to the action of the Coanda effect of the Coanda block 26 and the action of gas such as inflowing air at the curved line 30a,
30b, 30c, etc. are drawn and moved, and large particles (coarse particles) are moved outside the airflow, that is, outside the classification edge 18 according to the particle size of each particle and the magnitude of the inertial force. The particles are classified into the second fraction between the classification edges 18 and 17, the small particles are classified into the third fraction inside the classification edge 17, and the classified large particles are discharged from the discharge port 11 and the classified intermediate particles. The particles are discharged from the discharge port 12,
The classified small particles are discharged from the discharge port 13, respectively.

In the classification of the powder according to this embodiment, the classification point is the position where the powder jumps out into the classification chamber 32, and the classification edges 17 and 1 with respect to the lower end portion of the Coanda block 26.
8 is mainly determined by the edge tip position. further,
The classification point is affected by the flow rate of the classification airflow, the ejection speed of the powder from the raw material supply nozzle 16, and the like.

In the gas stream classifier of the present invention, the raw material powder is supplied from the raw material supply port 40, and the supplied raw material powder is emitted from the lower part of the powder raw material introduction port 42 from the outer periphery of the high pressure air introduction pipe 41, The high-pressure air ejected from the high-pressure air introduction pipe 41 is accelerated and dispersed well, and is instantly introduced from the raw material supply nozzle 16 into the classification chamber for classification, and is discharged to the outside of the classifier system. It is important that the powder introduced into the machine flies with propulsive force in a state where the aggregated powder is dispersed up to the primary particles without disturbing the trajectory of individual particles from the raw material supply nozzle 16 through the introduction port part in the classification chamber. Is. The particle flow flowing from the raw material supply nozzle 16 is such that when the raw material is introduced from above, the powder flow is introduced into the classification chamber 32 having the Coanda block 26 on the side of the opening of the raw material supply nozzle 16, Since the particle trajectory is formed according to the size of the particles without disturbing the flight trajectory of, the classification edge is moved in the direction along the streamline, and then the edge tip position of the classification edge is fixed,
It can be set to a predetermined classification point. Simultaneous movement of the classification edges 17 and 18 with the classification edge blocks 24 and 25 allows the edges to be oriented in the flow direction of the particle flow flying along the Coanda block 26.

Specifically, in FIG. 5, the tip of the classification edge 17 and the side surface of the Coanda block 26 are centered around, for example, the position O in the Coanda block 26 corresponding to the side surface of the tip opening 16a of the raw material supply nozzle 16. Distance L
₄ and the distance L ₁ between the side surface of the classification edge 17 and the side surface of the Coanda block 26 are moved up and down along the positioning member 33 by moving the classification edge block 24 up and down along the positioning member 34. It can be adjusted by moving and further rotating the tip of the classification edge 17 about the shaft 17a.

Similarly, the distance L ₅ between the tip of the classification edge 18 and the side wall of the Coanda block 26, the distance L ₂ between the side surface of the classification edge 17 and the side surface of the classification edge 18, or the side surface of the classification edge 18 and the side surface of the side wall 23. The distance L ₃ between and is moved up and down along the positioning member 35 by moving the classifying edge block 25 up and down along the positioning member 35, and the tip of the classifying edge 18 is further moved along the axis 18a. It can be adjusted by rotating it around the center.

That is, the Coanda block 26 and the classification edges 17 and 18 are installed on the side surface of the tip end opening 16a of the raw material supply nozzle 16, and the installation position of the classification edge block 24 and / or the classification edge block 25 is changed. As a result, the classification area of the classification chamber is expanded, and the classification point can be easily and significantly changed.

Therefore, the turbulence of the flow due to the tip of the classification edge can be prevented, and the flight speed of particles can be increased by adjusting the flow rate of the suction flow due to the reduced pressure through the discharge conduits 11a, 12a, and 13a, and thus in the classification region. In addition to improving the dispersion of the powder raw material, good classification accuracy can be obtained even at a higher dust concentration, not only can the product yield be prevented from lowering, but even with the same dust concentration, better classification accuracy and product yield can be obtained. It is possible to improve.

The distance L ₆ between the tip of the air intake edge 19 and the wall surface of the Coanda block 26 can be adjusted by rotating the tip of the air intake edge 19 about the shaft 19a. Further adjustment of the classification point is possible by adjusting the inflow rate and the inflow rate of gas from 14 and 15.

The above set distance is appropriately determined according to the characteristics of the powder raw material, and the true density of the colored resin particles is 0.3 to
When 1.4g / cm ³ , L ₀ <L ₁ + L ₂ <nL ₃ (n ≧ 1: real number) When 1.4g / cm ³ is exceeded, L ₀ <L ₃ <L ₁ + L ₂ must be satisfied. Is preferred. When this condition is satisfied, a product (medium powder) having a sharp particle size distribution can be efficiently obtained.

In general, the airflow type classifying apparatus of the present invention is used by being connected to each other by a communicating means such as a pipe and incorporated in an apparatus system. A preferred example of such a device system is shown in FIG. In the integrated device system shown in FIG. 6, the three-division classifier 1 (classification device shown in FIGS. 1 and 2), the constant quantity feeder 2, the vibration feeder 3, and the collecting cyclones 4, 5, 6 are connected by communication means. It will be.

In this apparatus system, the powder is fed to the constant quantity feeder 2 by an appropriate means, and then introduced into the three-division classifier 1 by the raw material feed nozzle 16 through the vibrating feeder 3. Upon introduction, 50-30
The powder is introduced into the three-division classifier 1 at a flow rate of 0 m / sec.
The size of the classification chamber of the three-division classifier 1 is usually [10
.About.50 cm] × [10-50 cm], so the powder has a density of 0.
The particles can be classified into three or more kinds of particle groups in an instant of 1 to 0.01 seconds or less. Then, the three-division classifier 1 classifies the particles into large particles (coarse particles), intermediate particles, and small particles. afterwards,
The large particles are sent to the collection cyclone 6 through the discharge conduit 11a and collected. Intermediate particles are discharged to the outside of the system through the discharge conduit 12a and collected by the collecting cyclone 5.
The small particles are discharged to the outside of the system via the discharge conduit 13a and collected. The collection cyclones 4, 5, and 6 can also function as suction decompression means for sucking and introducing the powder into the classification chamber through the raw material supply nozzle 16.

The airflow classifier of the present invention is particularly effective for classifying toner or a colored resin powder for toner used in an image forming method by electrophotography. In particular, it is effective when classifying a toner composition containing a binder resin having a low melting point, a low softening point or a low glass transition point.

When a toner composition using such a resin is subjected to a conventional classifier, a fused substance is apt to be generated at the particle passage tube from the injection air introduction pipe tip to the raw material supply nozzle and the classification edge tip, When a fused substance is generated, it deviates from an appropriate classification point. Furthermore, even if the flow rate is adjusted by suction decompression, it is difficult to obtain the required particle size distribution of the powder, and the classification efficiency is likely to decrease. Further, the fused material is likely to be mixed in the classified powder.

In the classifying apparatus of the present invention, the classification edges 17 and 18 are moved in the flow direction of the particle stream simultaneously with the classification edge blocks 24 and 25 to move the classification edges in the flow direction of the particle flow flying along the Coanda block 26. After passing the direction, the discharge conduits 11a, 12 are used as suction pressure reducing means.
By controlling the flow rate of the suction flow through a and 13a, the flight speed of particles can be increased and the dispersion of powder in the classification area can be further improved, so that the classification yield is improved and the particles at the tip of the classification edge are improved. It is possible to prevent or suppress the fusion of, and to perform highly accurate classification.

In the classifying apparatus of the present invention, the smaller the particle size of the powder, the more remarkable the effect is, and the weight average particle size is 10 in particular.
It is possible to obtain a classified product having a sharp particle size distribution when classifying a powder having a particle size of less than or equal to μm. Furthermore, a classified product having a sharp particle size distribution can be favorably obtained from a powder having a weight average diameter of 6 μm or less. It is possible.

Further, in the classifying device of the present invention, a stepping motor or the like is used as the moving means for moving the direction of the classification edge and the edge tip position, and a potentiometer or the like is used as the detecting means for detecting the edge tip position. It is more preferable to control the position of the tip of the classification edge by a control device for controlling and further automate the flow rate adjustment because a desired classification point can be obtained more accurately in a short time.

Example 1 100 parts by weight of styrene-butyl acrylate divinylbenzene copolymer (monomer polymerization weight ratio 80.0 / 1
9.0 / 1.0, weight average molecular weight Mw 350,000) -Magnetic iron oxide (average particle size 0.18 μm) 100 parts by weight-Nigrosine 2 parts by weight-Low molecular weight ethylene-propylene copolymer 4 parts by weight

Henschel mixer (FM-7
After thoroughly mixing with a No. 5 type, manufactured by Mitsui Miike Kakoki Co., Ltd., the mixture was kneaded with a twin-screw kneader (PCM-30 type, manufactured by Ikegai Tekko KK) set at a temperature of 150 ° C. The obtained kneaded material was cooled and coarsely pulverized with a hammer mill to 1 mm or less to obtain a coarsely crushed material for toner production. The coarsely pulverized product was finely pulverized by a collision type air flow pulverizer to obtain a pulverized raw material having a weight average diameter of 6.7 μm, and a true density was 1.73 g / cm ³ .

The pulverized raw material thus obtained is fed through the feeder 2 to the vibrating feeder 3 and the raw material feeding nozzle 16 (powder raw material feeding section 42, high pressure air introduction tube 41 and deforming tubular section 4).
3) was introduced into the multi-division classifier 1 shown in FIG. 1 for classifying into 3 types of coarse powder, medium powder and fine powder by utilizing the Coanda effect at a rate of 35.4 kg / h.

At the time of introduction, the suction force derived from the decompression in the system by the decompression of the collection cyclones 4, 5, 6 communicating with the discharge ports 11, 12, 13 and the raw material supply nozzle 16
The compressed air from the injection air introducing pipe 31 of the high-pressure air introducing pipe 41 attached to was used.

Further, in order to change the shape of the classification area, each set distance is set to L ₀ = 6 mm (height diameter of the raw material supply nozzle discharge port 16a) L ₁ = 34 mm (side surface of the classification edge 17 and the Coanda block 26) the distance between the side surfaces) L ₂ = 33mm (side and classifying edge of the classifying edge 17 1
8 of the distance between the side) L ₃ = 37mm (the distance between the classification distance between side surfaces and the side wall 23 of the edge 18) L ₄ = 15mm (side surface of the tip and the Coanda block 26 of the classifying edge 17) L ₅ = 35mm (Distance between tip of classification edge 18 and wall surface of Coanda block 26) L ₆ = 25 mm (distance between tip of air inlet edge 19 and wall surface of Coanda block 26) R = 14 mm (radius of arc of Coanda block 26) And classified.

The introduced finely pulverized raw material was instantly classified for 0.1 second or less. The classified medium powder is sharp with a weight average particle size of 6.9 μm (containing 22% by number of particles having a particle size of 4.0 μm or less and 1.0 volume% of particles having a particle size of 10.08 μm or more). It is possible to obtain a medium powder having a uniform distribution with a classification yield (ratio of the finally obtained medium powder to the total amount of the pulverized raw material charged) of 92.5%. Had.

The classified coarse powder was recycled to the crushing step.

The true density of the toner finely pulverized powder was measured by the following measuring device in the present invention. That is, as a measuring device, Micrometrics Accupic 1330
(Manufactured by Shimadzu Corporation) was used to weigh 5 g of toner finely pulverized powder to determine the true density.

The particle size distribution of the toner can be measured by various methods, but in the present invention, it was measured using the following measuring device.

That is, a Coulter Counter TA-II type or a Coulter Multisizer I is used as a measuring device.
I (manufactured by Coulter). As the electrolytic solution, an approximately 1% NaCl aqueous solution is prepared using first-grade sodium chloride. For example, ISOTON-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the aqueous electrolytic solution, and further 2 to 20 mg of measurement data is added. The electrolytic solution in which the sample is suspended is about 1 to 3 with an ultrasonic disperser.
The dispersion treatment was performed for a minute, and the volume and the number distribution of the toner were calculated by measuring the toner volume and number using the 100 μ aperture as the aperture with the measuring device. Then, a weight-based weight average system determined from the volume distribution according to the present invention was determined.

Examples 2 to 4 Table 1 obtained by crushing the same coarsely pulverized product for toner production as in Example 1 with a collision type air flow pulverizer
The pulverized raw material shown in Table 1 was used to perform classification with the same apparatus system except that the set distance in the classification area shown in Table 1 was used.

As shown in Tables 2 and 3, medium powder having a sharp distribution can be efficiently obtained.
It had excellent performance for toner.

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

[Table 3]

Examples 5-6 Unsaturated polyester resin 100 parts by weight Copper phthalocyanine pigment 4.5 parts by weight (CI Pigment Blue 15) Charge control agent 4.0 parts by weight

Henschel mixer (FM-7)
After thoroughly mixing with a No. 5 type, manufactured by Mitsui Miike Kakoki Co., Ltd., the mixture was kneaded with a twin-screw kneader (PCM-30 type, manufactured by Ikegai Iron Works Co., Ltd.) set at a temperature of 100 ° C. The obtained kneaded material was cooled and coarsely pulverized with a hammer mill to 1 mm or less to obtain a coarsely crushed material for toner production. The coarsely pulverized product was finely pulverized by a collision type air flow pulverizer to obtain a pulverized raw material having a weight average diameter of 6.5 μm and a true density of 1.08 g / cm ³ .

Using this pulverized raw material, classification was carried out in the same system as in Example 1 except that the classification conditions shown in Table 4 were used.

Further, the above-mentioned coarsely pulverized product was finely pulverized by a collision type air flow pulverizer to obtain a pulverized raw material (Example 6) having a weight average particle diameter of 5.5 μm, which was classified under the classification conditions shown in Table 4.

As shown in Tables 5 and 6, medium powder having a sharp distribution can be obtained efficiently.
It had excellent performance for toner.

[0063]

[Table 4]

[0064]

[Table 5]

[0065]

[Table 6]

Comparative Examples 1 to 3 The same toner raw material as in Example 1 was used to finely pulverize a coarsely pulverized product for toner production with a collision type air flow pulverizer to obtain a pulverized raw material having a weight average particle diameter of 6.9 μm ( Comparative Example 1) and a pulverized raw material (Comparative Example 2) having a weight average particle diameter of 5.5 μm were obtained.

Further, the toner raw material was changed to that in Example 5 to obtain a pulverized raw material having a weight average particle diameter of 6.0 μm (Comparative Example 3).

The classification was carried out according to the flow chart of FIG. 10, and the multi-division classifiers used were those shown in FIGS. 7, 8 and 9.

The classification conditions are as shown in Table 7,
The particle size distribution and the like of the intermediate powder obtained by classification are shown in Table 8 to Table 1.
It was as shown in 0.

[0070]

[Table 7]

[0071]

[Table 8]

[0072]

[Table 9]

[0073]

[Table 10]

[0074]

According to the airflow classifier of the present invention, fusion at the tip of the classifying edge can be satisfactorily prevented, and turbulent flow of the classifying airflow at the tip of the classifying edge can be satisfactorily prevented.
Accurate classification points can be obtained according to the specific gravity of various powders and classification airflow conditions, and the classification yield can be improved without shifting the classification points even when the device is operating in conjunction. In particular, it is effective in classifying a toner having a weight average particle diameter of 10 μm or less satisfactorily with a good yield.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an airflow type classification device of the present invention.

FIG. 2 is a perspective view of an airflow classification device of the present invention.

FIG. 3 is a perspective view of an airflow type classification device of the present invention.

FIG. 4 is a sectional view taken along the line AA ′ in FIG. 1;

5 is a diagram showing a main part of FIG.

FIG. 6 is an explanatory diagram showing an example of a classification process using the present invention.

FIG. 7 is a schematic cross-sectional view of a conventional airflow classifier.

FIG. 8 is a perspective view of a conventional airflow classifier.

FIG. 9 is a perspective view of a conventional raw material supply unit.

FIG. 10 is a diagram showing an example of a conventional classification process.

[Explanation of symbols]

 1, 101 Airflow classifier 2 Quantitative feeder 3 Vibration feeder 4, 5, 6 Collection cyclone 11, 12, 13 Discharge port 11a, 12a, 13a Discharge conduit 14, 15 Intake pipe 16 Raw material supply nozzle 17, 18, 117 , 118 Classification edge 19 Inlet edge 20 First gas introduction adjusting means 21 Second gas introduction adjusting means 22, 23 Side walls 24, 25, 124, 125 Classification edge block 26 Coanda block 27 Upper block 28, 29 Static pressure gauge 30a, 30b , 30c Solid particle scattering direction 31 Injection air introduction pipe 32 Classification chamber 33, 34, 35, 36 Positioning member 40 Raw material supply port 41 High pressure air introduction pipe 42 Powder raw material introduction nozzle

Claims (14)

[Claims] 1. A powder raw material supplied from a raw material supply nozzle in at least a classification area formed by a Coanda block and a plurality of classification edges, at least a coarse powder group, a medium powder group, and a fine powder due to the Coanda effect. In an airflow classifying device for classifying into groups, a raw material supply nozzle is provided on the upper surface of the airflow type classification device, and a Coanda block is provided on the side surface side of the raw material supply nozzle.
An air flow classifying device comprising a powder raw material supply unit for supplying a powder raw material and a high-pressure air introduction pipe to the rear end of the raw material supply nozzle. 2. The raw material supply nozzle is θ in the vertical direction.
The airflow classification device according to claim 1, wherein the airflow classification device is installed at an angle of 45 ° or less. 3. The coarse powder discharge port for discharging the classified coarse powder group is installed below the coarse powder discharge port for discharging the classified fine powder group. Airflow type classifier according to 2. 4. The air flow type classification device according to claim 1, wherein a high pressure air introduction pipe for accelerating the powder raw material is installed at a rear end portion of the raw material supply nozzle. 5. The airflow classifying apparatus according to claim 1, further comprising a powder raw material introduction port and a high pressure air introduction pipe for supplying high pressure air to a rear end portion of the raw material supply nozzle. 6. A high-pressure air introduction pipe is installed at the center of the powder raw material introduction port at the rear end of the raw material supply nozzle, and the powder raw material is introduced between the outer wall of the high-pressure air introduction pipe and the inner wall of the powder raw material introduction nozzle. The airflow type classification device according to any one of claims 1 to 5, which has a powder raw material introduction port for carrying out. 7. The airflow classification-type classification device according to claim 1, wherein the classification edge block having the classification edge can change its installation position so that the shape of the classification region can be changed. 8. The airflow classification device according to claim 1, wherein the installation position of the classification edge is movable, and the installation position of the classification edge is changeable. 9. The airflow classification device according to claim 1, wherein the classification edge block is provided with a classification edge so that a tip of the classification edge can be rotated. 10. The classification edge block can move its installation position in a vertical direction or a substantially vertical direction.
10. An airflow type classification device according to any one of 1 to 9. 11. The classification edge can move its installation position in a vertical direction or a substantially vertical direction.
An airflow classifier according to any one of 1. 12. A method for classifying colored resin particles containing at least a binder resin and a colorant with an airflow classifier utilizing the Coanda effect, and producing a toner from the classified powder, comprising the steps of: Colored resin particles are supplied to the raw material supply nozzle from the rear end portion of the raw material supply nozzle installed on the upper surface together with the high pressure air from the high pressure air introduction pipe through the powder raw material supply section, and the side surface side of the raw material supply nozzle In the classification area formed by the Coanda block and a plurality of classification edges installed in, the colored resin particles supplied from the raw material supply nozzle are divided into at least a coarse powder group, a medium powder group and a fine powder group by the Coanda effect. A method for producing a toner, characterized by classifying and producing a toner from the classified medium powder group. 13. A classification edge block having the classification edge is changed in its installation position so that the shape of the classification area can be changed, and the set distances of L ₀ > 0, L ₁ > 0, L _{2 are set.} > 0, L ₃ > 0 (In the formula, L ₀ indicates the height diameter of the raw material supply nozzle discharge port, L ₁ indicates the side of the classification edge for dividing into the medium powder group and the fine powder group, and Indicates the distance from the side surface of the facing Coanda block, and L ₂ is the side surface of the classification edge that separates into the medium powder group and the fine powder group, and the classification edge that separates into the coarse powder group and the medium powder group. represents the distance between the side surface of, L ₃ is set and the side of the classifying edge demarcating coarse powder group and the medium powder group and the binary, it indicates the distance between the side walls and the side surface facing thereto) and the colored resin True density of particles is 0.3-1.4 g / cm
^The method for producing a toner according to claim 12, wherein classification is performed under the condition that L ₀ <L ₁ + L ₂ <nL ₃ (n ≧ 1: real number) when ₃ . 14. classifying edge blocks having a該分classifying edge is, by changing its installation position to be able to change the shape of the classifying area, each of the set distance _{L 0> 0, L 1>} 0, L 2 > 0, L ₃ > 0 (In the formula, L ₀ represents the height diameter of the discharge port of the raw material supply nozzle, L ₁ represents the side surface of the classification edge for dividing into the medium powder group and the fine powder group, and Shows the distance from the side surface of the Coanda block facing L, and L ₂ is the side surface of the classification edge that divides into the medium powder group and the fine powder group, and the classification that separates into the coarse powder group and the medium powder group. The distance from the side surface of the edge, L ₃ represents the side surface of the classification edge that is divided into the coarse powder group and the medium powder group, and the distance between the side wall and the side surface facing this). If the true density of the resin particles exceeds 1.4 g / cm ^3, the serial to L ₀ <L ₃ <claim 12 for classification under an L ₁ + L ₂ The method for producing a toner.