JPH1115195A - Production of toner and production system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for production of toners by which the toners having a sharp grain size distribution is obtainable with high grinding efficiency and classification yield and continuous and stable production is possible. SOLUTION: A collision type air current pulverizing means has an acceleration pipe for accelerating the transportation of the material to be ground by a high-pressure gas and a grinding chamber for pulverizing the material to be ground. A collision member having a collision surface disposed to face the opening surface at the outlet of the acceleration pipe is included in the grinding chamber. The collision surface has a projecting projection central part and the outer peripheral collision surface has a conical shape. The coarsely ground material is introduced into the means described above where the material is pulverized. The pulverized powder is introduced into a first classifying stage for classifying the powder by utilizing intersecting air currents and a Coanda effect, by which the powder is classified to first coarse powder and first fine powder. The classified first coarse powder is introduced into a second classifying stage and the second coarse powder is introduced into the collision type air current pulverizing means where the powder is pulverized. The second pulverized powder is formed as the classified powder for forming toner particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a production method and a production system for efficiently pulverizing and classifying solid particles having a binder resin to obtain a toner for developing an electrostatic image having a predetermined particle size.

[0002]

2. Description of the Related Art In image forming methods such as electrophotography, electrostatography and electrostatic printing, a toner for developing an electrostatic image is used.

In recent years, high image quality of copiers and printers,
With higher definition, the performance required for toner as a developer has also become more severe, the particle size of the toner has become smaller, and the particle size distribution of the toner must be sharp, with no coarse particles and few fine powders. It is becoming required.

[0004] As a general method for producing a toner for developing an electrostatic image, there are a binder resin for fixing to a material to be transferred, various colorants for giving a color as a toner, and a method for giving a charge to particles. Charge control agent or JP-A-54-421
In the so-called one-component developing method as disclosed in JP-A-41-18 and JP-A-55-18656, various magnetic materials for imparting transportability and the like to the toner itself are used. And dry-mixing agent, and then melt-kneaded with a general-purpose kneading device such as a roll mill or extruder, and after cooling and solidifying, by various pulverizing devices such as a jet air flow pulverizer and a mechanical impact pulverizer. By making the particles finer and classifying them with various air classifiers, the toner particles can be adjusted to the required particle size. If necessary, a fluidizing agent, a lubricant and the like are dry-mixed to form a toner. When the toner is used in a two-component developing method, various magnetic carriers and a toner are mixed and then used for image formation.

As described above, in order to obtain toner particles which are fine particles, the method shown in the flowchart of FIG. 15 has conventionally been generally employed.

[0006] The coarsely crushed toner is continuously or sequentially supplied to the first classifying means, and the classified coarse powder mainly composed of coarse particles having a specified particle size or more is sent to the crushing means and crushed. It is circulated to the classifier.

[0007] The finely pulverized toner mainly composed of particles within the specified particle size range and particles not larger than the specified particle size is sent to the second classifying means, and the medium powder mainly composed of particles having the specified particle size is used. It is classified into a body and a fine powder mainly composed of a group of particles having a specified particle size or less.

Various pulverizing devices are used as pulverizing means. For pulverizing a coarsely pulverized toner mainly composed of a binder resin,
A jet air flow type pulverizer using a jet air flow as shown in FIG. 16, particularly an impingement type air flow pulverizer is used.

A collision type air flow pulverizer using a high-pressure gas such as a jet gas stream conveys a powder material by a jet stream, injects the powder material from an outlet of an acceleration tube, and opposes the powder material to an opening surface of an outlet of the acceleration tube. Then, the powder material is crushed by the impact force of the collision member.

For example, in the collision type air flow pulverizer shown in FIG. 16, an acceleration tube 162 connected to a high-pressure gas supply nozzle 161 is used.
A collision member 164 is provided opposite to the outlet 163 of the, and the high-pressure gas supplied to the acceleration pipe 162 sucks the powder raw material into the acceleration pipe 162 from the powder raw material supply port 165 communicated in the middle of the acceleration pipe 162. Then, the powder raw material is ejected together with the high-pressure gas to collide with the collision surface 166 of the collision member 164, crushed by the impact, and the crushed material is discharged from the crushed material discharge port 167.

However, in the collision type air current pulverizer of FIG. 16, since the supply port 165 for the pulverized material is provided in the middle of the accelerating tube 162, the pulverized material sucked and introduced into the accelerating tube 162 is Immediately after passing through the pulverized material supply port 165, the gas is dispersed in the high-pressure gas flow while rapidly changing the flow path toward the acceleration pipe outlet 163 by the high-pressure gas flow ejected from the high-pressure gas supply nozzle 161 and rapidly accelerated. In this state, relatively coarse particles of the material to be crushed flow in the lower part of the acceleration tube due to the effect of inertia force, and relatively fine particles flow in the higher part of the acceleration tube. Without being dispersed, the pulverizing chamber 1 is separated into a stream having a high concentration of the material to be pulverized and a stream having a low concentration.
Collision with the collision member 164 in the portion 68 causes the crushing efficiency to be easily reduced and the processing capacity to be easily reduced.

Furthermore, since the collision surface 166 is apt to locally generate a portion having a high dust concentration composed of the crushed material and the crushed material in the vicinity thereof, the crushed material contains a low melting point substance such as a resin. Is liable to cause fusion, coarsening, agglomeration and the like of the material to be ground. In addition, when the object to be ground has abrasion properties, local powder wear is likely to occur on the collision surface of the collision member and the acceleration tube, the frequency of replacement of the collision member is increased, and continuous stable production is achieved. There was a point to improve in terms of aspects.

Therefore, the tip of the collision surface of the collision member is
A conical shape having an apex angle of 110 ° to 175 ° (JP-A-1-254266), or a collision plate shape having a projection on a plane where the collision surface intersects perpendicularly with the extension of the central axis of the collision member ( Japanese Utility Model Laid-Open No. 1-148740) has been proposed. In these crushers, the local increase in dust concentration near the collision surface can be suppressed, so that the fusion, coarsening, and aggregation of the crushed material can be somewhat reduced, and the crushing efficiency is slightly improved. However, further improvements are desired.

For example, when obtaining a toner having a weight average particle diameter of 8 μm and a volume percentage of particles of 4 μm or less of 1% or less, a collision type having a classification mechanism for removing a coarse powder region is used. The raw material is pulverized to a predetermined average particle size by a pulverizing means such as an air-flow type pulverizer and classified, and the pulverized material after the coarse powder is removed is subjected to another classifier to remove the fine powder to obtain a desired medium powder. Gaining body.

The weight-average particle size is data measured using a Coulter Counter TA-II or Coulter Multisizer II manufactured by Coulter Electronics Co., Ltd. (USA) using an aperture of 100 μm.

[0016] In such a conventional method, a problem is that a particle group from which coarse particles having a certain particle size or more have been completely removed must be sent to the second classifying means for removing fine powder. Therefore, the load on the pulverizing means increases, and the throughput decreases. In order to completely remove a group of coarse particles having a specific particle size or more, excessive pulverization is unavoidable, and as a result, a phenomenon such as a decrease in yield in the second classifying means for removing fine powder in the next step is likely to occur. There is a problem.

In the second classification means for removing fine powder, aggregates composed of ultrafine particles may be generated, and it is difficult to remove aggregates as fine powder. In that case, the agglomerates are mixed into the final product, which makes it difficult to obtain a product having a fine particle size distribution. Further, the aggregates break down in the toner and become extremely fine particles, which is one of the causes of deteriorating image quality.

Regarding the second classification means for removing the fine powder, various airflow classifiers and methods have been proposed. Among these, there are a classifier using a rotary wing and a classifier without a movable part. Among them, a classifier without a movable part includes a fixed wall centrifugal classifier and an inertial force classifier. Classifiers utilizing such inertia include an elbow jet classifier commercialized by Nippon Steel Mining and O.
kuda. S. and Yasukuni.
J. : Proc. Inter. Symposium
on powder Technology '8
1,771 (1981) has been proposed.

Generally, many different properties are required for a toner, and in order to obtain such required properties, the raw materials to be used as well as the manufacturing method are often determined. In the toner classification process, the classified particles are required to have a sharp particle size distribution. It is also desired to efficiently and stably produce high quality toner at low cost.

Furthermore, in recent years, toner particles have been gradually miniaturized in order to improve image quality in copying machines and printers. In general, as the material becomes finer, the function of the interparticle force increases, but the same applies to resin and toner.

In particular, when trying to obtain a toner having a sharp particle size distribution with a weight average diameter of 10 μm or less, the conventional apparatus and method cause a decrease in classification yield. Further, in the case of obtaining a toner having a sharp particle size distribution with a weight average diameter of 8 μm or less, it is remarkable that the classification yield is reduced particularly in the conventional apparatus and method.

Even if a desired product having a fine particle size distribution can be obtained under the conventional method, the process becomes complicated, the classification yield is reduced, the production efficiency is low, and the cost is high. That is inevitable. This trend is
The smaller the predetermined particle size, the more noticeable.

Japanese Patent Application Laid-Open No. 63-101858 (corresponding to US Pat. No. 4,844,349) proposes a method and an apparatus for producing a toner using a multi-divided classifying means as the first classifying means, pulverizing means and second classifying means. ing. However, there is a need for a method and system for more stably and efficiently producing a toner having a weight average particle diameter of 8 μm or less.

[0024]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a manufacturing method which solves the above-mentioned various problems in a conventional method for manufacturing a toner for developing an electrostatic image. And

Another object of the present invention is to provide a toner production system for efficiently producing a toner for developing an electrostatic image.

That is, an object of the present invention is to provide a production method and a production system for efficiently producing a toner for developing electrostatic images having a fine particle size distribution.

The present invention also relates to a method of melting and kneading a mixture containing a binder resin, a colorant and an additive, cooling the melt-kneaded product, and then obtaining fine particles having a predetermined particle size distribution from a group of solid particles formed by pulverization. It is an object of the present invention to provide a method and a system for efficiently producing a product (used as a toner) with high yield.

Another object of the present invention is to provide a method and system for efficiently producing a toner for developing an electrostatic image having a sharp particle size distribution having a weight average diameter of 10 μm or less (further, 8 μm or less). I do.

[0029]

According to the present invention, a mixture containing at least a binder resin and a colorant is melt-kneaded, the kneaded product is cooled, and the cooled product is pulverized by pulverizing means to obtain a coarse pulverized product. It has an accelerating tube for conveying and accelerating the object to be pulverized by a high-pressure gas and a pulverizing chamber for finely pulverizing the object to be pulverized. In the pulverizing chamber, an opening face of an outlet of the accelerating tube is opposed. A collision member having a collision surface provided is provided, and a rear end portion of the acceleration tube has a material supply port for supplying a material to be ground into the acceleration tube, and the collision surface protrudes. A collision having a protruding central portion, an outer peripheral collision surface having a cone shape, and a crushing chamber having a side wall for further crushing the crushed object crushed by the collision member by collision. Introducing the above coarsely pulverized material into the airflow fine pulverizing means and finely pulverizing,
The finely pulverized powder is introduced into a first classifying step of classifying the powder using the crossed airflow and the Coanda effect, and is classified into a first coarse powder and a first fine powder, and the classified first coarse powder A second coarse powder is introduced into an impinging airflow fine pulverizing means and finely pulverized, and the second fine powder is classified into a classifying powder for producing toner particles. And a manufacturing system.

In the airflow type classification apparatus, which is the first classification step of the present invention, the shape of the classification area can be changed by changing the installation position of the classification edge block having the classification edge, and the classification is performed accordingly. Points can be easily and significantly changed. Along with the change of the installation position of the classification edge in accordance with the change of the installation position of the classification edge block, the classification point can be greatly changed by adjusting the position of the classification edge tip by making the tip of the classification edge rotatable. ,
In the vicinity of the classification edge tip, the classification point can be adjusted with high accuracy without generating turbulence in the airflow.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the accompanying drawings.

FIG. 1 is an example of a flowchart showing the outline of the manufacturing method of the present invention. In the present invention, a predetermined amount of the pulverized raw material is introduced into an impingement-type airflow pulverizing means and pulverized, and the finely pulverized powder after the pulverization classifies the powder using the crossed airflow and the Coanda effect. Introduced into the 1 classifying step, and classified into a first coarse powder and a first fine powder, and the classified first fine powder is generally supplied to a melt-kneading process for producing a pulverized raw material and is reused, or , Be discarded. First
The coarse powder is introduced into the second classification step and classified as a classification powder for producing toner particles, and is classified into a second coarse powder and a second fine powder. The classified second fine powder is used as it is as a toner, or is mixed with an additive such as hydrophobic colloidal silica and used later as a toner. The second coarse powder classified in the second classification step is introduced into the impingement-type airflow fine pulverizing means and finely pulverized again.

In the production method and the production system of the present invention, the weight average particle diameter is 10 μm or less (particularly 8 μm or less) by controlling the classification and pulverization conditions.
It is possible to efficiently generate a toner having a small particle size and a sharp particle size distribution.

FIG. 2 shows an example of the apparatus system of the present invention.

In this apparatus system, the pulverized raw material to be used as the toner powder raw material is sent to the pulverizer 28 via the first constant feeder 21, pulverized, and then introduced into the first classifier 1, where it is classified. The collected fine powder is collected through the collection cyclone 2, the classified coarse powder is introduced into the second classifier 22, the classified coarse powder is again introduced into the pulverizer 28, and the classified fine powder is collected. Collected in the collection cyclone 23.

As an example of the first classifier used in the present invention, an air flow classifier of the type shown in FIGS. 3 and 4 will be exemplified.

The side wall 15 forms a part of the classification chamber, and the classification edge block 16 has the classification edge 13. The classification edge 13 is rotatable about an axis 13a, and the classification edge can be rotated to change the classification edge tip position. The classification edge block 16 can slide the installation position up and down in FIG.
Accordingly, the knife edge type classification edge 13 also slides up and down in the same direction or almost the same direction. Due to the classification edge 13, the classification zone of the classification chamber 12 is used to separate the Coanda block 1 for separating a fine powder group of a predetermined size or less.
A first classification area formed between 1 and the classification edge 13;
It is divided into two parts: a predetermined particle size and a second classification region for separating a coarse powder group having a predetermined particle size or more.

A raw material supply nozzle edge 14 is provided below the raw material supply nozzle 10, and a Coanda block 11 having a long elliptical arc drawn in an extending direction of a left tangent line of the raw material supply nozzle is provided. The material supply nozzle edge block 17 installed on the right side of the classifying chamber 12 includes a knife edge type material supply nozzle edge 14 on the left side of the classifying chamber 12, and further, the classification is provided on the right side of the classifying chamber 12. An intake pipe 6 opening to the chamber 12 is provided (see FIG. 2). The intake pipe 6 is provided with a gas introduction adjusting means 7 such as a damper and a static pressure gauge 8. The material supply nozzle edge block 17 includes a material supply nozzle edge 14. The raw material supply nozzle edge 14 is rotatable about a shaft 14a, and the raw material supply nozzle edge can be rotated to change the tip position of the raw material supply nozzle edge.

The positions of the classification edge 13 and the raw material supply nozzle edge 14 are adjusted according to the type and desired particle size of the powder to be classified.

The first fine powder outlet 5 having a predetermined particle size or less on the left side of the classifying chamber 12 is connected to a communicating means such as a pipe, and may be provided with an opening / closing means such as a valve means.

In FIG. 3, the powder to be classified discharged from the pulverized material discharge port 55 is instantaneously introduced from the raw material supply nozzle 10 into the classification device, classified and discharged out of the classification system. The classifier to be introduced into the apparatus is disturbed from the raw material supply nozzle 10 by the introduction part in the classifier using the high pressure gas of the pulverizer 28 connected to the upper part of the raw material supply nozzle 10. It is important to fly with propulsion without doing so. The particle stream flowing from the inside of the raw material supply nozzle 10 is divided into a classifying chamber 12 having a Coanda block 11 on the side of the opening of the raw material supply nozzle 10.
When the powder flow is introduced into the particle stream, the particle trajectory is dispersed according to the particle size without disturbing the trajectory of the particle, so that the particle stream is formed. Can be set to

That is, the Coanda block 11 and the classification edge 13 are installed on the side of the raw material supply nozzle edge 14 of the raw material supply nozzle 10, and the shape of the classification area of the classification room is changed, and the classification point is easily and largely adjusted. can do.

Therefore, it is possible to prevent the flow from being disturbed by the tip of the classification edge, and to increase the flying speed of the particles by adjusting the flow rate of the suction flow through the coarse powder discharge pipe 4 and the fine powder discharge pipe 5 due to the reduced pressure. Dispersion of finely pulverized material in the classification area is improved, good classification accuracy is obtained even at higher dust concentration, and cohesive ultrafine powder (weight average of 2 μm or less) can be reliably excluded from the finely pulverized material. Not only can the yield of the product be reduced, but also the classification accuracy and the yield of the product can be improved at the same dust concentration.

Further, it can be adjusted by rotating the tip of the raw material supply nozzle edge 14 about the shaft 14a, whereby the flow rate and / or the flow rate of the gas from the intake pipe 6 and the raw material supply nozzle 10 can be controlled. By adjusting
Further adjustment of the classification point is possible. This makes it possible to efficiently obtain a product (medium powder) having a sharp distribution in the second classification means.

Further, in the classifier shown in FIG. 3, a stepping motor or the like is used as a moving means to move the position of the classifying edge, and a pornometer or the like is used as a detecting means to detect the position of the end of the edge. It is more preferable to control the position of the leading edge of the classification edge by the control device and to further automate the flow rate control, because a desired classification point can be obtained more quickly and more accurately.

As the pulverizing means used in the present invention, for example, a collision type air flow pulverizer of the type shown in FIGS.

In FIG. 5, the object 42 supplied from the object supply pipe 41 is formed between the inner wall of the accelerating tube throat 44 of the accelerating tube 43 and the outer wall of the high-pressure gas jet nozzle 45. The material to be pulverized is supplied to the accelerating tube 43 from a supply port 46 (also a throat portion).

It is preferable that the center axis of the high-pressure gas ejection nozzle 45 and the center axis of the acceleration tube 43 are substantially coaxial.

On the other hand, the high-pressure gas is introduced from the high-pressure gas supply port 47 and passes through the high-pressure gas chamber 48, preferably through a plurality of high-pressure gas introduction pipes 49, and from the high-pressure gas ejection nozzle 45 toward the acceleration pipe outlet 50. It gushes while expanding rapidly toward. At this time, due to the ejector effect generated near the accelerating tube throat section 44, the crushed material 42
Is rapidly accelerated while being uniformly mixed with high-pressure gas in the accelerating tube throat section 44 from the supplied material supply port 46 toward the direction of the accelerating tube outlet 50 while being entrained by the gas coexisting with the crushed object 42. Then, it collides with the collision surface 52 of the collision member 51 facing the acceleration tube outlet 50 in a state of a uniform solid-gas mixed flow without unevenness of the dust concentration. Since the impact force generated at the time of collision is given to the individual particles (object 42 to be pulverized) that are sufficiently dispersed, very efficient pulverization can be performed.

The pulverized material pulverized on the collision surface 52 of the collision member 51 is further subjected to a secondary collision (or tertiary collision) with the side wall 54 of the pulverization chamber 53, and the pulverized material disposed behind the collision member 51. It is discharged from the material discharge port 55.

The collision surface 52 of the collision member 51 may be a cone-shaped collision surface as shown in FIG. 5 or a collision surface having a conical projection as shown in FIG. This is preferable in that the dispersion is uniformly performed and the higher-order collision with the side wall 54 is efficiently performed. Further, when the pulverized material discharge port 55 is located behind the collision member 51, the pulverized material can be discharged smoothly.

By providing a cone-shaped projection with a central part protruding on the material collision surface as shown in FIG. 6, the solid-gas mixed flow of the pulverized raw material and compressed air ejected from the acceleration tube impinges on the surface of the projection. After the primary pulverization on the surface 52 and the secondary pulverization on the outer peripheral collision surface 52 ′, the pulverization is tertiary pulverized on the pulverization chamber side wall 54.
At this time, the apex angle α formed by the collision surface 52 of the projection surface of the collision member
(°) and the inclination angle β (°) of the outer peripheral collision surface 52 ′ and the central axis of the accelerating tube with respect to the perpendicular plane satisfies 0 <α <90, β> 0 30 ≦ α + 2β ≦ 90. Good crushing is performed.

When α ≧ 90, the reflected flow of the primary pulverized material on the projection surface disturbs the flow of the solid-gas mixed flow ejected from the acceleration tube, which is not preferable.

When β = 0, the outer peripheral collision surface becomes almost perpendicular to the solid-gas mixed flow, and the reflected flow at the outer peripheral collision surface flows toward the solid-gas mixed flow. This is undesirable.

When β = 0, the powder concentration increases on the outer peripheral collision surface, and when a powder of a thermoplastic resin or a powder containing a thermoplastic resin as a main component is used as a raw material, the melting point on the outer peripheral collision surface is increased. Kimonos and aggregates are likely to occur. When such a fusion product is generated, stable operation of the apparatus becomes difficult.

When α and β satisfy α + 2β <30, the impact force of the primary pulverization on the projection surface is weakened, and the pulverization efficiency is lowered, which is not preferable.

When α and β satisfy α + 2β> 90, the reflected flow at the outer peripheral collision surface flows downstream of the solid-gas mixed flow, so that the impact force of the tertiary pulverization on the side wall of the pulverization chamber is weakened and the pulverization efficiency is reduced. cause.

As described above, when α and β satisfy 0 <α <90, β> 030 ≦ α + 2β ≦ 90, primary, secondary, and tertiary pulverization are efficiently performed to improve the pulverization efficiency. Can be.

More preferable α and β are 0 <α <805 and 5 <β <40.

The number of collisions is increased as compared with the conventional pulverizer,
In addition, one of the features of the present invention is to make the collision more effective, and it is possible to improve the pulverization efficiency, to prevent generation of a fused material at the time of pulverization, and to perform stable operation. .

FIG. 7 is an enlarged view of the pulverizing chamber 53 in the impinging airflow pulverizer of FIG. In FIG. 7, the collision member 5
The closest distance L ₁ between the edge 61 and the side wall 54 is shorter than the distance L ₂ between the front wall 62 of the crushing chamber facing the collision surface 52 and the edge 61 of the collision member 51. However, this is important in order not to increase the powder concentration in the grinding chamber near the acceleration tube outlet 50. Further, recently because contact distance L ₁ is shorter than the closest distance L _2, it is possible to efficiently perform the secondary collision of the pulverized material in the sidewall. As shown in FIG. 16, in the pulverizer having the collision surface inclined as described above, the collision surface
Compared with a crusher having a collision member 164 having a plane shape of 90 ° with respect to 62, when crushing a resin or a sticky substance, fusion of the material to be crushed, agglomeration, coarsening hardly occurs, Pulverization at a high dust concentration becomes possible. In addition, wear is not concentrated locally, so that the life can be extended and stable operation can be achieved.

If the inclination of the accelerating tube 43 in the long axis direction is preferably in the range of 0 ° to 45 ° with respect to the vertical direction, the crushed material 42 is closed at the crushed material supply port 46. And can be processed.

When the fluidity of the material to be crushed is not good, when the cone-shaped member is provided below the material supply pipe 41,
Although it is a small amount, it tends to stay at the lower part of the cone-shaped member, and the inclination of the acceleration tube 43 is 0 with respect to the vertical direction.
If it is within the range of from 20 to 20 (more preferably from 0 to 5), there is no stagnation of the material to be ground in the lower cone-shaped portion, and the material to be ground can be smoothly supplied to the acceleration tube.

FIG. 8 is a sectional view taken along the line AA ′ in FIG. From FIG. 8, it is understood that the object 42 is smoothly supplied to the acceleration tube 43.

The shortest distance L between the front wall 62 at the surface of the acceleration tube outlet 50 which intersects perpendicularly with the extension of the center axis of the acceleration tube, and the outermost peripheral end 61 of the collision surface 52 of the collision member 51 opposed thereto.
_{In the case of 2} , the diameter of the collision member 51 is preferably in the range of 0.2 to 2.5 times in terms of pulverization efficiency, and more preferably in the range of 0.4 to 1.0 times. The distance L ₂ is less than 0.2 times the diameter of the impact member 51, may have to dust concentration of the impact surface 52 near an abnormally high and, if exceeding 2.5 times, weakened impact force, the As a result, the crushing efficiency tends to decrease.

The outermost end 61 and the side wall 54 of the collision member 51
The shortest distance L ₁ between the range of 0.1 times the diameter of the impact member 51 twice is preferable. In the distance L ₁ is less than 0.1 times the diameter of the impact member 51, a large pressure loss during passage of high pressure gas, easy grinding efficiency is lowered, there is a tendency that fluidity of pulverized material does not go smoothly, twice In the case of exceeding, the effect of the secondary collision of the object to be crushed on the inner wall 54 of the crushing is reduced, and the crushing efficiency tends to be reduced.

More specifically, the length of the acceleration tube 43 is 5
Preferably, the diameter of the collision member 51 is 30 to 500 mm.
It is preferable to have a length of 300 mm.

Further, it is preferable that the collision surface 52 and the side wall 54 of the collision member 51 are made of ceramic from the viewpoint of durability.

FIG. 9 is a sectional view taken along the line BB 'in FIG. In FIG. 9, the distribution state of the crushed object in a plane perpendicular to the vertical direction passing through the crushed object supply port 46 is indicated by an acceleration tube 43.
The greater the inclination of the line with respect to the vertical direction, the more skewed the distribution. Therefore, the inclination of the acceleration tube 43 is 0 ° to 5 °.
Is the best, and has been confirmed by an experiment using a transparent acrylic resin internal observation accelerating tube as the accelerating tube 43.

FIG. 10 is a sectional view taken along the line CC 'in FIG. In FIG. 10, the pulverized material is discharged rearward through the space between the collision member support 91 and the side wall 54.

FIG. 11 is a sectional view taken along the line DD ′ in FIG. In FIG. 11, two high-pressure gas introduction pipes 92 are provided.
It may be a book or three or more.

FIG. 12 is a schematic view showing another specific example of the impingement type air current pulverizer used in the present invention. It is the same as FIG. 5 except that the shape of the high-pressure gas injection nozzle 40 is different.

As the second classification means used in the present invention, an air flow classifier that classifies by forced centrifugal force using forced vortex is used. For example, Hosokawa Micron's Teaplex (ATP) classifier, micron separator,
A Dona Selec classifier manufactured by Nippon Donaldson Co., Ltd., a turbo classifier classifier manufactured by Nisshin Seiko Co., Ltd., and the like can be given.

Preferably, an air classifier as shown in FIG. 13 is used to improve the classification accuracy of fine powder and coarse powder.

In FIG. 13, reference numeral 121 denotes a cylindrical main body caging. A classification chamber 122 is formed inside the main body casing 121, and the classification chamber 122 is formed.
There is a guide room 123 at the bottom.

The classifier is of an individual drive type and has a classification room 1
A forced vortex using centrifugal force is generated in 22 and classified into coarse powder and fine powder. A classification rotor 124 is provided in the classification chamber 122, and the powder material and the air fed into the guide chamber 123 are swirled and flow into the classification chamber 122 from between the classification rotors 124. The powder raw material is introduced from the raw material input port 125, and the air is taken in together with the pulverized raw material from the input ports 126 and 127 and further from the raw material input port 125. The powder raw material is carried to the classification chamber 122 together with the inflow air. The air and the powder material flowing in the guide chamber 123 through the inlet 125 are
It is preferable that the particles are uniformly distributed to the respective classifying rotors 124 in order to classify with high accuracy. The flow path up to the classifying rotor 124 needs to have a shape in which concentration is unlikely to occur, and the position of the inlet 125 is not limited to this.

The classifying rotor 124 is movable, and the distance between the classifying rotors can be adjusted. Speed control of the classifying rotor is performed through a frequency converter 128.

The fine powder discharge pipe 129 is connected to a suction fan 131 via a fine powder collecting means 130 such as a cyclone or a dust collector.
The suction force is applied to.

The air-flow classifier preferably used as the second classifier has the above-mentioned structure. The powder material pulverized by the above-mentioned collision type air-pulverizer, the air used for the pulverization, and the newly supplied air are used. When the air containing the pulverized raw material is supplied into the guide chamber 123 from the inlet 125, the air containing the powder material flows from the guide chamber 123 to between the classifying rotors 124.

The powder material that has flowed into the classification chamber 122 is dispersed by a classification rotor that rotates at high speed, and is separated into coarse powder and fine powder by centrifugal force acting on each particle. The coarse powder passes through a coarse powder discharging hopper 132 connected to the lower part of the main body casing, and passes through a rotary valve 133 and a second coarse powder discharging pipe 19 as a second communicating means to be covered by the above-mentioned impingement type air current pulverizer. The pulverized material is supplied to the supply pipe 41. Further, the second fine powder is discharged to the fine powder collecting means 130 through the fine powder discharge pipe 129.

By using the airflow classifier shown in FIG. 13 in combination with the above-mentioned collision airflow crusher, mixing of fine powder into the crusher is favorably suppressed or prevented, and excessive pulverization of the crushed material is prevented. In addition, the classified coarse powder is smoothly supplied to the pulverizer, further uniformly dispersed in the accelerating tube, and pulverized well in the pulverizing chamber, so that the yield of the pulverized material and the energy efficiency per unit weight are reduced. Can be enhanced.

In the rotary classifier, the classification point is determined by the number of revolutions of the classification rotor. However, since the efficiency of the pulverizing means has not been good conventionally, it is difficult to obtain a toner having a small diameter, and it is difficult to obtain the toner. It took a lot of effort.
However, in the present invention, further improvement of the performance of the pulverizing means allows the powder to be further finely divided efficiently, so that classification in the fine particle region can be performed. In the case of a rotary classifier, the classification point can be easily changed only by changing the number of revolutions of the rotor, so that the operability is excellent.

The raw material to be introduced into the pulverizing means is preferably 2 mm or less, preferably 1 mm or less. A material obtained by introducing the pulverized raw material into the medium pulverization step and pulverizing to about 10 to 100 μm may be used as the raw material in the present invention.

In a conventional pulverization-classification method using a classifier for removing only fine particles as shown in the flow chart of FIG. 15 as the second classification means, a certain regulation is applied to the particle size of the powder at the end of pulverization. It has been required that a coarse particle group having a particle size or more is completely removed. For this reason, the pulverizing process requires more pulverizing capacity than necessary, resulting in excessive pulverization and a reduction in pulverization efficiency. This phenomenon becomes more conspicuous as the particle size of the powder becomes smaller, and in particular, when a medium powder having a weight average particle size of 3 to 10 μm is obtained, the efficiency is significantly reduced.

In the method of the present invention, fine powder particles are removed by the first classification means. Therefore, even if a coarse particle group exceeding a certain specified particle size is contained in a certain ratio in the particle size of the powder at the end of the pulverization, it is removed satisfactorily by the second classification means in the next step, so that the restriction in the pulverization step is limited. And the capacity of the pulverizer can be maximized, the pulverization efficiency is improved, and there is little tendency to cause over-pulverization. Therefore, the fine powder can be removed very efficiently, and the classification yield can be improved satisfactorily.

In the conventional classification method for classifying medium powder and fine powder, agglomeration of fine particles which causes fogging of a developed image is liable to occur due to a long residence time at the time of classification.
When aggregates are formed, it is generally difficult to remove the aggregates from the medium powder. However, according to the method of the present invention, even if the aggregates are mixed in the pulverized material, the Coanda effect and the Coanda effect by the first classifying means can be reduced. Agglomerates are disintegrated and / or removed as fine powder by the impact of high-speed movement, and even if there is any agglomerate that has escaped disintegration, it can be removed by the second classification means, so that the agglomerate can be removed efficiently. Things are possible.

The production method and system of the present invention can be preferably used for producing toner particles used for developing an electrostatic image.

To prepare a toner for developing an electrostatic image, a colorant or a magnetic powder, a vinyl-based or non-vinyl-based thermoplastic resin, a charge control agent, and other additives as necessary are added to a Henschel mixer or a ball mill. After sufficiently mixing with a mixer such as a roll, a kneader, an extruder, the pigment or dye is dispersed or dissolved in the resin mixed with each other by melting, kneading and kneading using a hot kneader. After cooling and solidification, pulverization and classification are performed to obtain a toner. In the pulverizing step and the classifying step, the production method and system of the present invention are used.

Next, the constituent materials of the toner will be described.

When a heating and pressing fixing device or a heating and pressing roller fixing device having a device for applying oil is used as the binder resin used for the toner, the following binder resins for toner can be used. is there.

For example, homopolymers of styrene such as polystyrene, poly-p-chlorostyrene and polyvinyltoluene and their substituted products; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene Copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethacrylic copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene- Styrene-based copolymer of vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer; polyvinyl chloride, phenol Resin, natural modified Resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, cumaroindene resin, Petroleum resins and the like can be used.

In the heat and pressure fixing method or the heat and pressure roller fixing method in which little or no oil is applied, a so-called offset phenomenon in which a part of a toner image on a toner image support member is transferred to a roller, Further, the adhesion of the toner to the toner image supporting member is an important problem.
Toners that fix with less heat energy tend to block or cake during storage or in a developing unit, and these problems must also be considered at the same time. The physical properties of the binder resin in the toner are most significantly involved in these phenomena. However, according to the study of the present inventors, when the content of the magnetic substance in the toner is reduced, the toner image is not supported during fixing. Although the adhesion of the toner to the body is improved, offset tends to occur, and blocking or caking tends to occur. Therefore, when using a heat and pressure roller fixing method in which almost no oil is applied, selection of a binder resin is more important. Preferred binder resins include crosslinked styrenic copolymers and crosslinked polyesters.

Examples of comonomers for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and the like.
Double such as dotesyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. A monocarboxylic acid having a bond or a substituted product thereof; for example, a dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like; and substituted products thereof: for example, vinyl chloride, vinyl acetate, Vinyl esters such as vinyl benzoate; vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether ; Vinyl monomers such as may be used alone or two or more.

As the crosslinking agent, a compound having two or more polymerizable double bonds is mainly used, for example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, etc .; for example, ethylene glycol diacrylate, ethylene glycol Glycol dimethacrylate,
Carboxylic acid esters having two double bonds such as 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone; and compounds having three or more vinyl groups; Are used alone or as a mixture.

When the pressure fixing method or the light heat pressure fixing method is used, a binder resin for a pressure fixing toner can be used.
Polymethylene, polyurethane elastomer, ethylene-
Examples include an ethyl acrylate copolymer, an ethylene-vinyl acetate copolymer, an ionomer resin, a styrene-butadiene copolymer, a styrene-isoprene copolymer, a linear saturated polyester, and paraffin.

It is preferable to use a charge control agent in the toner by blending (internally adding) it to the toner particles. By the charge control agent, optimal charge amount control according to the phenomenon system becomes possible, and in particular, in the present invention, it is possible to further stabilize the balance between the particle size distribution and the charge,
By using the charge control agent, it is possible to further clarify the function separation and the complementarity for higher image quality for each particle size range described above. Examples of the positive charge control agent include denatured products such as nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate;
More than one kind can be used in combination. Among these, charge control agents such as nigrosine compounds and quaternary ammonium salts are particularly preferably used.

Also, the general formula

[0098]

Embedded image

R ₁ : H, CH ₃ R ₂ , R ₃ : a homopolymer of a monomer represented by a substituted or unsubstituted alkyl group (preferably C 1 to C 4);
A copolymer with a polymerizable monomer such as styrene, acrylate or methacrylate as described above can be used as a positive charge control agent. In this case, these charge control agents are Or a part).

As the negative charge control agent, for example, organometallic complexes and chelate compounds are effective. Examples thereof are aluminum acetylacetonate, iron (II) acetylacetonate, chromium 3,5-di-tert-butyl-salicylate. Or zinc or the like, particularly preferably an acetylacetone metal complex, a salicylic acid-based metal complex or a salt, particularly preferably a salicylic acid-based metal complex or a salicylic acid-based metal salt.

The above-mentioned charge control agent (having no function as a binder resin) is preferably used in the form of fine particles. In this case, the number average diameter of the charge control agent is specifically preferably 4 μm or less (more preferably 3 μm or less).

When internally added to the toner, such a charge control agent is preferably used in an amount of 0.1 to 20 parts by weight (more preferably 0.2 to 10 parts by weight) based on 100 parts by weight of the binder resin.

When the toner is a magnetic toner, the magnetic material contained in the magnetic toner includes iron oxides such as magnetite, γ-iron oxide, ferrite, and iron-rich ferrite;
Metals such as iron, cobalt, nickel or these metals and aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth,
Cadmium, calcium, manganese, selenium, titanium,
Alloys with metals such as tungsten and vanadium, and mixtures thereof, and the like can be given.

These ferromagnetic materials have an average particle size of 0.1 to 1
μm, and preferably about 0.1 to 0.5 μm.
The amount is from 60 to 110 parts by weight, preferably from 65 to 100 parts by weight, per 100 parts by weight of the resin component.

As the colorant used in the toner, conventionally known dyes and / or pigments can be used. For example, carbon black, phthalocyanine blue, peacock blue, permanent red, lake red, rhodamine lake, Hanser yellow, permanent yellow, benzidine yellow and the like can be used. The content is 0.1 to 20 parts by weight, preferably 0.5 to 20 parts by weight, based on 100 parts of the binder resin, and 12 parts by weight to improve the transparency of the OHP film on which the toner image is fixed. Parts by weight or less, more preferably 0.5 to 9 parts by weight.

According to the present invention described above, it is possible to obtain a toner having a sharp particle size distribution from a toner raw material having a weight average diameter of 10 μm or less, and particularly from a toner raw material having a weight average diameter of 8 μm or less. And a fine particle size distribution can be obtained.

The particle size distribution of the toner can be measured by various methods. In the present invention, the measurement was performed using the following measuring apparatus.

That is, a Coulter Counter TA-II or Coulter Multisizer II (manufactured by Coulter) was used as a measuring device. As an electrolytic solution, an approximately 1% NaCl aqueous solution is prepared using primary sodium chloride. For example, ISOTON R-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 dispersing agent to 100 to 150 ml of the aqueous electrolyte solution, and the measurement sample is further added to 2 to 20 ml.
Add mg. The electrolyte in which the sample is suspended is subjected to dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and the volume and number distribution of the toner are measured by measuring the volume and the number of the toner by using the measuring device with an aperture of 100 μm. Was calculated. Then, a weight-based weight average particle diameter determined from the volume distribution according to the present invention was determined.

[0109]

The present invention will be described in more detail with reference to the following examples.

Example 1 100 parts by weight of styrene-butyl acrylate-divinylbenzene copolymer (weight ratio of monomer polymerization: 80.0 / 19.0 / 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

After the above-mentioned ingredients were mixed well with a Henschel mixer (Model FM-75, manufactured by Mitsui Miike Kakoki Co., Ltd.), a twin-screw kneader (PCM-75) set at a temperature of 150 ° C.
(Type 30; Ikegai Iron Works Co., Ltd.). 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 obtained toner raw material was pulverized and classified by an apparatus system shown in FIG.

The impingement type air current crusher 28 uses an apparatus having the structure shown in FIG. 5 and has a tilt in the longitudinal direction of the acceleration tube with respect to the vertical line (hereinafter referred to as the acceleration tube inclination) of about 0 ° (that is, the acceleration tube inclination). (Substantially vertically installed), and the collision member 51 shown in FIG. 6 was used. Α = 55 °, β = 10 ° of this collision member
FIG. 7 shows an example using an outer diameter (diameter) of 100 mm.
Accelerator tube exit 50 intersecting at right angles to the accelerator tube center axis shown in FIG.
And the surface, the shortest distance L ₂ between the outermost edge of the impact surface 52 of the collision member 51 opposed thereto is 50 mm, the grinding chamber 5
For the shape of No. 3, a cylindrical grinding chamber having an inner diameter of 150 mm was used.
Therefore, the shortest distance L ₁ is 25mm. 2nd classifier 2
2 uses a classifier having the configuration shown in FIG. p.
m. Driven by

The first classifier 1 was introduced into a two-divider classifier shown in FIG. 3 and classified into ultrafine powder and fine powder by utilizing the Coanda effect. At the time of introduction, it is introduced into the collection cyclone 2 and again into the second classifier 22 by communicating with the discharge pipes 4 and 5.

The impact type pulverizer 1 is supplied from the injection feeder 35 at a rate of 35.0 kg / h by the table type first constant-quantity feeder 21 through the supply pipe 125.
08 is supplied from the material supply pipe 41 at a pressure of 6.0 k.
g / cm ² (G), pulverized using 6.0 Nm ³ / min compressed air, and then supplied to the airflow classifier 1 via the raw material supply nozzle 10 to classify the fine powder (first fine powder) Was collected by the collection cyclone 2. The coarse powder is introduced into a second airflow classifier and is subjected to closed-circuit pulverization. The classified fine powder is entrained by cyclone 2
Collected at 3. At this time, the weight average diameter of the fine powder (second fine powder) was 6.9 μm (particles having a particle diameter of 4.0 μm or less
1.3% of particles having a particle size of 10.08 μm or more containing several percent by number.
(% By volume), and excellent performance for toner.

At this time, the ratio (that is, the classification yield) of the finally obtained fine powder to the total amount of the charged raw materials was 90%. When the obtained fine powder was observed with an electron microscope, an aggregate of 4 μm or more in which ultrafine particles were aggregated was not substantially found.

Example 2 Using the same toner raw material as in Example 1, pulverization and classification were carried out in the same apparatus system.

The impingement type air current pulverizer having the configuration shown in FIG. 5 was used for pulverization under the same apparatus conditions as in Example 1.
The second classifier uses the same device as in the first embodiment, and the rotation speed of the rotor is 3400 rpm. p. m. I made it.

The pulverized raw material was supplied at a rate of 28.0 kg / h, and a weight average particle diameter of 6.1 μm (27% by number of particles having a particle diameter of 4.0 μm or less, and particles having a particle diameter of 10.08 μm or more having a particle diameter of 0.18 μm or more were added. Fine powder having a sharp distribution (containing 5% by volume) was obtained with a classification yield of 85%.

Example 3 Using the same toner raw material as in Example 1, pulverization and classification were carried out in the same apparatus system.

The impingement type air current pulverizer having the structure shown in FIG. 5 was used for pulverization under the same apparatus conditions as in Example 1.
The second classifier uses the same device as in the first embodiment, and the rotation speed of the rotor is 4200 rpm. p. m. I made it.

The pulverized raw material was supplied at a rate of 28.0 kg / h, and a weight average particle diameter of 5.7 μm (containing 14% by number of particles having a particle diameter of 3.17 μm or less, and particles having a particle diameter of 10.08 μm or more were added in an amount of 1.0%). Fine powder having a sharp distribution (containing 0% by volume) was obtained with a classification yield of 84%.

Example 4 100 parts by weight of unsaturated polyester resin 4.5 parts by weight of copper phthalocyanine pigment (CI Pigment Blue 15) 4.0 parts by weight of charge control agent (chromium salicylate complex)

After the above-mentioned ingredients were mixed well with a Henschel mixer (Model FM-75, manufactured by Mitsui Miike Kakoki Co., Ltd.), a twin-screw kneader (PCM-75) set at a temperature of 100 ° C.
(Type 30; Ikegai Iron Works Co., Ltd.). 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 impingement type air current pulverizer used was an apparatus having the configuration shown in FIG. 5, and pulverization was performed under the same apparatus conditions as in Example 1. The same multi-class classifier as in Example 1 was used. Also,
As the second classifier, the same apparatus as that used in Example 1 was used. The diameter of the rotor was 200 mm, and the number of revolutions of the rotor was 3500 rpm. p. m.
It was used.

In the injection feeder 35 at a rate of 33.0 kg / h of the pulverized raw material in the table type first constant-quantity feeder 21 via the supply pipe 125, the supply pipe 41 of the impingement type air flow pulverizer 108 Supplied by pressure 6.
After being pulverized by using compressed air of 0 kg / cm ² (G) and 6.0 Nm ³ / min, the pulverized powder is supplied to the first airflow classifier 1 through the raw material supply nozzle 10 and the classified fine powder (first The fine powder is collected by the collection cyclone 2, the coarse powder is introduced into the second airflow classifier and is subjected to closed circuit pulverization, and the classified fine powder is transferred to the cyclone 23 while being entrained by the suction air from the exhaust fan 131. And collected. At this time, the fine powder (second fine powder) had a weight average particle diameter of 6.8 μm (21% by number of particles having a particle diameter of 4.0 μm or less, and 1.4% by volume of particles having a particle diameter of 10.08 μm or more. (Contained), and had excellent performance for toner.

At this time, the ratio of the fine powder finally obtained to the total amount of the pulverized raw materials charged (that is, the classification yield) was 88%.

Example 5 Using the same toner raw material as in Example 4, pulverization and classification were carried out in the same apparatus system.

The impingement type air current pulverizer having the structure shown in FIG. 5 was used and pulverization was performed under the same apparatus conditions as in Example 1. The second classifier uses the same device as in the first embodiment, and has a rotation speed of 3900 rpm. p. m. I went in.

The pulverized raw material was supplied at a rate of 30.0 kg / h, and a weight average particle diameter of 6.4 μm (containing 24% by number of particles having a particle diameter of 4.0 μm or less, and particles having a particle diameter of 10.08 μm or more were added in an amount of 1.0%). Fine powder having a sharp distribution (containing 0% by volume) was obtained with a classification yield of 85%.

Comparative Example 1 Materials having the same formulation as in Examples 1 to 3 were mixed well with a Henschel mixer (Model FM-75, manufactured by Mitsui Miike Kakoki Co., Ltd.) and then biaxially kneaded at a temperature of 150 ° C. (PCM-3
(Type 0, manufactured by Ikegai Iron Works Co., Ltd.). The obtained kneaded material was cooled, coarsely pulverized to 1 mm or less with a hammer mill,
A crushed product for toner production was obtained.

The obtained toner raw material was pulverized and classified by an apparatus system shown in FIG. However, the impingement type air current pulverizer used was the pulverizer shown in FIG. 16, and the first classifier and the second classifier had the configuration shown in FIG.

In FIG. 14, reference numeral 201 denotes a cylindrical main body casing, 202 denotes a lower casing, and a hopper 203 for discharging coarse powder is connected to a lower portion thereof. A classifying chamber 204 is formed inside the main body casing 201. The classifying chamber 204 is closed by an annular guide chamber 205 attached to the upper part of the classifying chamber 204 and a conical (umbrella-shaped) upper cover 206 having a high center. I have.

A plurality of louvers 207 arranged in the circumferential direction are provided on a partition wall between the classifying chamber 204 and the guide chamber 205, and the powder material and the air sent into the guide chamber 205 are separated from each louver 207 by the classifying chamber. It is swirled to flow into 204.

The upper part of the guide chamber 205 is formed by a space between the conical upper casing 213 and the conical upper cover 206.

A classifying louver 209 arranged in the circumferential direction is provided at the lower part of the main body casing 201, and classifying air for generating a swirling flow from the outside to the classifying chamber 204 is supplied to the classifying louver 20.
Incorporated through 9.

At the bottom of the classifying chamber 204, a conical (umbrella-shaped) classifying plate 210 having a higher central portion is provided.
A coarse powder discharge port 211 is formed around the outside. A fine powder discharge chute 212 is connected to the center of the classifying plate 210,
The lower end of the chute 212 is bent into an L-shape, and the bent end is located outside the side wall of the lower casing 202. Further, the chute is connected to a suction fan via fine powder collecting means such as a cyclone or a dust collector, and a suction force is applied to the classification chamber 204 by the suction fan, so that the suction flowing into the classification chamber 204 from between the louvers 209. The swirling flow required for classification is caused by air.

The air flow classifier has the above-described structure. When air containing the above-mentioned crushed material for toner production is supplied from the supply tube 208 into the guide chamber 205, the air containing the crushed material is supplied from the guide chamber 205 to the guide chamber 205. After passing between the louvers 207, it swirls into the classification chamber 204 while flowing at a uniform concentration while being dispersed.

The crushed material flowing into the classifying chamber 204 while swirling is swirled by a suction air flow generated from a suction fan connected to the fine powder discharge chute 212 and flowing from between the classifying louvers 209 at the lower part of the classifying chamber. The coarse powder which is centrifuged into coarse powder and fine powder by the centrifugal force acting on each particle, and which circulates around the outer periphery in the classification chamber 204 is discharged from the coarse powder outlet 211 and discharged from the lower hopper 203. You.

The fine powder moving to the center along the upper inclined surface of the classification plate 210 is discharged by the fine powder discharge chute 212.

The pulverized raw material is supplied at a rate of 13.0 kg / h from the table type first constant-quantity feeder 21 to the airflow classifier shown in FIG. The obtained coarse powder is supplied through a coarse powder discharge hopper 203 from a pulverized material supply port 165 of a collision type air pulverizer shown in FIG.
cm ² (G), using compressed air of 6.0 nm ³ / min, after being crushed, while being mixed with the toner pulverizing material that is supplied at the raw material introduction part, circulated again airflow classifier, The fine powder classified by the closed circuit pulverization is introduced into the second classification means 22 in FIG. 14 while being accompanied by the suction air from the exhaust fan, and collected by the cyclone 31.

As a result, the weight average particle diameter was 6.9 μm (27% by number of particles having a particle diameter of 4.0 μm or less were contained, and the particle diameter was 10.3 μm.
It contains 1.5% by volume of particles of 08 μm or more. ) Was obtained with a classification yield of 61%. Thus, both the pulverization efficiency and the classification yield were inferior to Examples 1 and 3.

Comparative Example 2 Using the same toner raw materials as in Examples 1 to 3, pulverization and classification were performed by the apparatus system shown in FIG. However, the impingement type air-flow crusher used had the configuration shown in FIG. 16, and the first classifier and the second classifier had the configuration shown in FIG. 14 and were crushed under the same apparatus conditions as in Comparative Example 1. .

The pulverized raw material was supplied at a rate of 10.0 kg / h, and a weight average particle size of 6.1 μm (containing 33% by number of particles having a particle size of 4.0 μm or less and 0.3% of particles having a particle size of 10.08 μm or more was added. (Volume of 5% by volume) was obtained at a classification yield of 60%. Thus, compared to Example 2, both the grinding efficiency and the classification yield were inferior.

Comparative Example 3 Materials having the same formulation as in Examples 4 and 5 were mixed well with a Henschel mixer (Model FM-75, manufactured by Mitsui Miike Kakoki Co., Ltd.), and then biaxially kneaded at a temperature of 100 ° C. Machine (PCM
-30 type, manufactured by Ikegai Iron Works Co., Ltd.). 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 obtained toner raw material was pulverized and classified by an apparatus system shown in FIG. However, the impingement type air current pulverizer used was the pulverizer shown in FIG. 16, and the first classifier and the second classifier had the configuration shown in FIG.

The pulverized raw material is supplied at a rate of 12.0 kg / h from the table type first constant-quantity feeder 21 to the airflow classifier shown in FIG. The obtained coarse powder is supplied through a coarse powder discharge hopper 203 from a pulverized material supply port 165 of a collision type air pulverizer shown in FIG.
cm ² (G), using compressed air of 6.0 nm ³ / min, after being crushed, while being mixed with the toner pulverizing material that is supplied at the raw material introduction part, circulated again airflow classifier, The fine powder classified by the closed circuit pulverization is introduced into the second classification means 22 in FIG. 14 while being accompanied by the suction air from the exhaust fan, and collected by the cyclone 31.

As a result, the weight average particle size was 6.5 μm (28% by number of particles having a particle size of 4.0 μm or less were contained, and the particle size was 10.3 μm.
(Containing 1.6 volume% of particles having a particle size of 08 μm or more) was obtained with a classification yield of 59%. Thus, Examples 4 and 5
As compared with, both the grinding efficiency and the classification yield were inferior.

[0149]

According to the method and system for producing a toner of the present invention, a toner having a sharp particle size distribution can be obtained with high pulverization efficiency and a high classification yield.
There is an advantage that generation of coarse particles is prevented, device-like abrasion due to toner components is prevented, and continuous and stable production can be performed. In addition, by using the toner manufacturing method and the manufacturing system of the present invention, compared with the conventional method, the image density is stable and high, the durability is good, and the excellent predetermined particle size free from image defects such as fog and poor cleaning is obtained. The toner for developing an electrostatic image having the same can be obtained at low cost.

In particular, it is possible to efficiently obtain a toner having a sharp particle size distribution with a weight average diameter of 10 μm or less, and further efficiently obtain a toner having a sharp particle size distribution with a weight average diameter of 8 μm or less. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining a manufacturing method and a manufacturing system of the present invention.

FIG. 2 is a schematic diagram showing a specific example of an apparatus system for performing the manufacturing method of the present invention.

FIG. 3 is a schematic cross-sectional view of a classification device as a specific example of the first classification means in the present invention.

FIG. 4 is a three-dimensional view of a classification device which is a specific example of the first classification means in the present invention.

FIG. 5 is a schematic cross-sectional view of a pulverizing apparatus which is a specific example of the impingement type air current pulverizing means in the present invention.

FIG. 6 is a diagram illustrating an example of a collision member in the crusher.

FIG. 7 is an enlarged view of a grinding chamber in FIG.

8 is a sectional view taken along line A-A 'in FIG.

9 is a sectional view taken along line B-B 'in FIG.

FIG. 10 is a sectional view taken along line C-C 'in FIG.

11 is a sectional view taken along the line D-D 'in FIG.

FIG. 12 is a schematic cross-sectional view of a pulverizing apparatus as another specific example of the impingement type air current pulverizing means in the present invention.

FIG. 13 is a schematic cross-sectional view of a preferred specific example of the second classification means in the present invention.

FIG. 14 is a schematic cross-sectional view showing an example of a pneumatic classifier used for a conventional first or second classifier.

FIG. 15 is a flowchart for explaining a conventional manufacturing method.

FIG. 16 is a schematic sectional view of a conventional collision-type airflow pulverizer.

FIG. 17 is a schematic diagram showing a specific example of a manufacturing system for implementing a conventional manufacturing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st classifier 2 Collection cyclone 3 Finely pulverized material discharge pipe 4 Coarse powder discharge pipe 5 Fine powder discharge pipe 6 Inlet pipe 7 Gas introduction control means 8 Static pressure gauge 9 Fine powder 10 Raw material supply nozzle 11 Coanda block 12 Classification chamber 13 Classification Edge 14 Material supply nozzle edge 15 Classification chamber side wall 16 Classification edge block 17 Material supply nozzle edge block 18 Positioning member 21 First quantitative feeder 22 Second classifier 23 Collection cyclone 28 Crusher 33 Product 40 High pressure gas injection nozzle 41 Pulverized material supply pipe 42 Pulverized material 43 Acceleration tube 44 Throat part 45 High pressure gas injection nozzle throat part 46 Pulverized material supply port 47 High pressure gas supply port 48 High pressure gas chamber 49 High pressure gas introduction pipe 50 Acceleration pipe outlet 51 Collision member 52 Collision Surface 53 crushing chamber 54 crushing chamber side wall 55 crushed material discharge port 61 Edge of projecting member 62 Front wall of crushing chamber 91 Collision member support 92 High-pressure gas introduction pipe 121 Main casing 122 Classification chamber 123 Guide chamber 124 Classification rotor 125 Raw material input port 126 Air input port 128 Frequency converter 129 Fine powder discharge pipe 130 134 Fine powder collection means 131 Suction fan 132 Hopper 133 Rotary valve 135 Dispersion louver 161 High pressure gas supply nozzle 162 Acceleration tube 163 Acceleration tube outlet 164 Collision member 165 Powder material supply port 166 Collision surface 167 Pulverized material discharge port 168 Pulverization chamber 201 Main casing 202 Lower casing 203 Hopper 204 Classification room 205 Guide room 206 Upper cover 207 Louver 208 Supply cylinder 209 Classification louver 210 Classification plate 211 Coarse powder discharge port 212 Fine powder discharge chute 213 Upper case Packaging

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B07B 9/00 B07B 9/00 Z

Claims (28)

[Claims] 1. A mixture containing at least a binder resin and a colorant is melt-kneaded, the kneaded material is cooled, and the cooled material is pulverized by a pulverizing means to obtain a coarsely pulverized material. It has an accelerating tube for accelerating and a pulverizing chamber for finely pulverizing the object to be pulverized.In the pulverizing chamber, a collision member having a collision surface provided opposite to an opening surface of an outlet of the accelerating tube is provided. Is provided, at the rear end of the accelerating tube has a pulverized material supply port for supplying the pulverized material into the accelerating tube, the collision surface has a protruding central portion protruding,
And the outer peripheral collision surface has a cone shape,
Collision type airflow fine pulverization means having a side wall for further pulverizing the object to be pulverized by the collision member by collision,
The above coarsely pulverized material is introduced and finely pulverized, and the finely pulverized powder is introduced into a first classification step of classifying the powder using a crossed airflow and a Coanda effect, so that a first coarse powder and a first fine powder are obtained. The first coarse powder that has been classified is introduced into a second classifying step, and the second coarse powder is introduced into an impingement-type airflow fine pulverizing means to be finely pulverized, and the second fine powder is classified into toner particles. A method for producing a toner, which is a powder. 2. The first classifying step is performed at least in a classifying region formed by a Coanda block and a classifying edge.
A pneumatic classifier for classifying powder material supplied from a material supply nozzle having a material supply edge into at least a coarse powder group and a fine powder group by the Coanda effect, wherein the classification edge having the classification edge 2. The method according to claim 1, wherein the installation position of the block can be changed so that the shape of the classification area can be changed. 3. The method for producing a toner according to claim 2, wherein the setting position of the classification edge is movable with a change in the setting position of the classification edge block. 4. The method according to claim 2, wherein the classifying block is provided with the classifying edge such that a tip of the classifying edge is rotatable. 5. The method according to claim 2, wherein the classification area is formed by a Coanda block and a classification edge. 6. The method according to claim 2, wherein the classification area is further formed between the classification edge and the side wall. 7. The classification edge is provided in a classification edge block, and the classification edge is movable with the movement of the classification edge block.
7. The method for producing a toner according to any one of items 1 to 6, above. 8. A classification area for classifying fine powder particles smaller than a predetermined particle size is formed between the Coanda block and the classification edge, the classification edge and the side wall being provided. 8. The method according to claim 2, wherein a classification region for classifying a group of coarse particles having a predetermined particle size and a particle size larger than the predetermined particle size is formed. 9. The method according to claim 2, wherein the classification edge block has a classification edge such that a tip of the classification edge is rotatable. 10. The Coanda block is provided in contact with a raw material supply nozzle, and forms a group of fine particles smaller than a predetermined particle size, a coarse particle size larger than a predetermined particle size, and a fine particle group smaller than a predetermined particle size. The method for producing a toner according to any one of claims 2 to 9, wherein a classification region for classification by the Coanda effect is provided in the particle group. 11. The installation position of the classifying edge is regulated by a positioning member so as to be movable in the same direction or substantially the same direction as the moving direction of the classifying edge block. Or a method for producing a toner. 12. The classification edge is rotatably supported by a shaft, the distance between the shaft and the Coanda block is variable, and the classification edge is between the shaft and a side wall of the classification area. The method for producing a toner according to claim 2, wherein the distance is variable. 13. The material supply edge is rotatably supported by a shaft, and the rotation of the material supply edge changes the distance between the tip of the material supply edge and the Coanda block. A method for producing a toner according to any one of claims 2 to 12, wherein: 14. The toner according to claim 2, wherein the raw material supply edge is provided on the raw material supply edge block so that the tip of the raw material supply edge is rotatable. Production method. 15. A mixture containing at least a binder resin and a colorant is melt-kneaded, the kneaded material is cooled, and the cooled material is crushed by a crushing means to obtain a coarsely crushed material, and the material to be crushed is transported by a high-pressure gas. It has an accelerating tube for accelerating and a pulverizing chamber for finely pulverizing the object to be pulverized.In the pulverizing chamber, a collision member having a collision surface provided opposite to an opening surface of an outlet of the accelerating tube is provided. Is provided, at the rear end of the accelerating tube has a pulverized material supply port for supplying the pulverized material into the accelerating tube, the collision surface has a protruding central portion protruding,
And the outer peripheral collision surface has a cone shape,
Collision type airflow fine pulverization means having a side wall for further pulverizing the object to be pulverized by the collision member by collision,
The above coarsely pulverized material is introduced and finely pulverized, and the finely pulverized powder is introduced into a first classification step of classifying the powder using a crossed airflow and a Coanda effect, so that a first coarse powder and a first fine powder are obtained. The first coarse powder that has been classified is introduced into a second classifying step, and the second coarse powder is introduced into an impingement-type airflow fine pulverizing means to be finely pulverized, and the second fine powder is classified into toner particles. A toner production system characterized by being powdered. 16. The third classifying step includes, at least in a classifying region formed by a Coanda block and a classifying edge, a powder material supplied from a material supply nozzle having a material supply edge is at least roughly roughened by a Coanda effect. Airflow classification means for classifying into a powder group and a fine powder group, wherein a classification edge block having the classification edge can change its installation position so that the shape of the classification area can be changed. The toner production system according to claim 15, wherein: 17. The toner manufacturing system according to claim 16, wherein the setting position of the classification edge can be moved with the change of the setting position of the classification edge block. 18. The toner production system according to claim 16, wherein the classification block is provided with the classification edge so that the tip of the classification edge is rotatable. 19. The classification area according to claim 1, wherein the classification area is formed by a Coanda block and a classification edge.
19. The system for producing a toner according to any one of 6 to 18. 20. The toner production system according to claim 16, wherein said classification area is further formed between a classification edge and a side wall. 21. The toner according to claim 16, wherein the classification edge is provided in a classification edge block, and the classification edge is movable as the classification edge block moves. Manufacturing system. 22. One classification edge is provided,
A classification area for classifying a group of fine powder smaller than a predetermined particle size is formed between the Coanda block and the classification edge, and a coarse particle having a predetermined particle size and larger than the predetermined particle size is formed between the classification edge and the side wall. 22. The toner production system according to claim 16, wherein a classification area for classifying the group is formed. 23. The toner manufacturing system according to claim 16, wherein the classification edge block has a classification edge such that a tip of the classification edge is rotatable. 24. The Coanda block is provided in contact with a raw material supply nozzle, and forms a fine particle group having a particle diameter smaller than a predetermined particle diameter and a coarse particle larger than a predetermined particle diameter and a predetermined particle diameter from the raw material supply nozzle. The toner production system according to any one of claims 16 to 23, wherein a classification region for classifying by a Coanda effect is provided for the particle group. 25. The installation position of the classification edge is regulated by a positioning member so as to be movable in the same direction or substantially the same direction as the movement direction of the classification edge block. Or a toner production system. 26. The classification edge is pivotally supported by a shaft, the distance between the shaft and the Coanda block is variable, and the classification edge is between the shaft and a side wall of the classification area. 26. The toner manufacturing system according to claim 16, wherein the distance is variable. 27. The material supply edge is rotatably supported by a shaft, and the rotation of the material supply edge changes the distance between the tip of the material supply edge and the Coanda block. The toner production system according to any one of claims 16 to 26. 28. The toner according to claim 16, wherein the raw material supply edge is provided on the raw material supply edge block so that the tip of the raw material supply edge is rotatable. Manufacturing system.