JP3302270B2 - Manufacturing method of toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a toner, and more particularly, to a method for efficiently pulverizing and classifying a solid particle containing a binder resin to obtain a sharp particle size distribution and an aggregate. The present invention relates to a method for producing a toner for developing an electrostatic image formed of a high-quality classified product containing no high-quality toner and the like with high production efficiency.

[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, as the image quality and definition of copiers and printers have become higher, the performance required for toner as a developer has become even more severe, the particle size of the toner has become smaller, and the particle size distribution of the toner has become coarser. There has been a growing demand for sharp particles that do not contain particles and that contain few ultrafine powders.

[0003] 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. Using a charge control agent as a raw material, or
In a so-called one-component developing method as disclosed in JP-A-42141 and JP-A-55-18656, in addition to these, various magnetic materials for imparting transportability or the like to the toner itself are used. Accordingly, for example, other additives such as a release agent and a fluidity imparting agent are added, and after these materials are dry-mixed, melt-kneaded with a general-purpose kneading device such as a roll mill or an extruder, and obtained. After cooling and solidifying the kneaded material, the kneaded material is refined by various pulverizers such as a jet air crusher and a mechanical collision pulverizer, and the obtained coarsely pulverized material is introduced into various air classifiers to perform classification. A classified product having a required particle size is obtained as a toner, and if necessary, a fluidizing agent, a lubricant and the like are externally added and dry-mixed to obtain a toner to be used for image formation. Further, in the case of the toner used in the two-component developing method, various magnetic carriers are mixed with the above-mentioned toner and then used for image formation.

[0004] In addition, in order to obtain toner particles composed of fine particles having a required particle size, a method shown in a flowchart of FIG. 17 has conventionally been generally employed. That is, as shown in FIG. 17, the powder raw material composed of the coarsely pulverized toner is first continuously or sequentially supplied to the first classification means and classified into coarse powder and fine powder. Of the classified items,
Coarse powder mainly composed of a group of coarse particles having a specified particle size or more is sent to a pulverizing means and pulverized. Is done.
Then, the fine powder prepared into the particle group containing particles within the specified particle size range and particles having the specified particle size or smaller is sent to the second classifying means, and the medium powder mainly composed of the particle group having the specified particle size. And a fine powder mainly composed of particles having a particle size equal to or less than a specified particle size (hereinafter, referred to as
Ultra-fine powder). The obtained medium powder is used as a classified product for producing a toner.

Various pulverizers are used as pulverizing means used in the above-mentioned conventional classification / pulverization process. For pulverizing a coarse toner powder mainly composed of a binder resin, a jet air flow as shown in FIG. A jet air-type pulverizer using the same, particularly, an impingement-type air current pulverizer is used. In such an impingement type air current pulverizer using a high-pressure gas such as a jet air flow, a powder raw material, which is an object to be ground, is transported by a jet air flow, is injected from an outlet of an acceleration tube, and the powder raw material is discharged from an outlet of the acceleration tube. The powder raw material is pulverized by the impact force of a collision with a collision surface of a collision member provided to face the opening surface of the powder material. For example, in the collision type air flow pulverizer shown in FIG. 18, the collision member 164 is provided so as to face the outlet 163 of the acceleration tube 162 to which the high-pressure gas supply nozzle 161 is connected.
With the high-pressure gas supplied to 62, the powder raw material is sucked into the acceleration pipe 162 from the powder raw material supply port 165 communicating with the acceleration pipe 162, and the powder raw material is ejected together with the high-pressure gas to form the collision member 164. The powder material is caused to collide with the collision surface 166, and the pulverized material is pulverized by the impact force.
7 to discharge.

However, in the collision type air-flow crusher shown in FIG. 18, since the supply port 165 for the crushed object is provided in the middle of the acceleration tube 162, the powder which is the crushed object sucked and introduced into the acceleration tube 162. Immediately after passing through the pulverized material supply port 165, the raw material is dispersed in the high-pressure airflow while changing the flow path toward the acceleration pipe outlet 163 by the high-pressure airflow ejected from the high-pressure gas supply nozzle 161, and is rapidly accelerated. . In this state, relatively coarse particles of the material to be pulverized flow in the lower part of the accelerating tube due to the effect of inertia force, while relatively fine particles flow in the higher part of the accelerating tube. The raw material particles are not sufficiently uniformly dispersed, and the collision member 164 in the pulverizing chamber 168 is separated into a high concentration flow and a low concentration flow.
Partially concentrate on the collision. For this reason, there has been a problem that the pulverization efficiency is apt to decrease, and the treatment capacity is likely to decrease.

Further, the collision surface 166 is located near the
Since a high portion of dust concentration consisting of a locally crushed material and a crushed crushed material is likely to occur, particularly when the crushed material contains a low melting point material such as a resin, Fusing, coarsening, agglomeration, and the like of the material to be ground are likely to occur. Further, when the object to be ground has abrasion properties, local powder wear is likely to occur on the collision surface 166 of the collision member 164 and the accelerating tube 162, and the replacement frequency of the collision member 164 increases. There was a point to be improved from the viewpoint of continuous stable production.

On the other hand, the collision surface 16 of the collision member 164
6 has a conical shape having an apex angle of 110 ° to 175 ° (JP-A-1-254266), or has a projection on a plane where the collision surface intersects perpendicularly with the extension of the central axis of the collision member. A collision plate having the following shape (Japanese Utility Model Laid-Open No. 1-148740) has been proposed. In these pulverizers, since it is possible to suppress a local increase in the dust concentration near the collision surface, it is possible to somewhat reduce the fusion, coarsening, aggregation, and the like of the pulverized material and slightly improve the pulverization efficiency. However, in some cases, further improvement has been desired.

For example, if the weight average particle size is 8 μm and
In order to obtain a toner having a particle size distribution in which particles having a particle size of 1 μm or less are 1% or less by volume%, a pulverizing means such as an impingement air flow type pulverizer having a classification mechanism for removing a coarse powder region is used.
After pulverizing the raw material to a predetermined average particle size, the mixture is classified by a classifier to remove coarse powder, and the obtained pulverized product is subjected to another classifier as a second classification means to remove ultrafine powder. To obtain a medium powder having a desired particle size distribution. Here, 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.

[0010] However, a problem with such a conventional method is that the second classifying means for the purpose of only removing the ultrafine powder requires a method of completely removing a coarse particle group having a certain particle size or more. Therefore, there is a problem that the load on the crushing means is increased and the throughput is reduced. Further, if it is attempted to completely remove a coarse particle group having a particle size larger than a certain specified particle size, excessive pulverization is apt to occur, and a large amount of ultrafine powder is generated in the pulverization step. As a result, there is a problem that a phenomenon such as a decrease in yield is easily caused in the second classification means for removing the ultrafine powder in the next step.
Further, the second classification means for removing ultrafine powder has a problem that it is difficult to remove the aggregate as ultrafine powder when aggregates composed of ultrafine particles are generated. There is. In this case, the agglomerates are mixed into the final product, and as a result, it is difficult to obtain a toner product having a fine particle size distribution. Therefore, this is one of the causes of lowering the image quality.

Conventionally, various airflow classifiers and airflow classifier methods have been proposed for the second classifier for the purpose of removing ultrafine powder as described above. Among them, a rotary blade is used. There are classifiers and classifiers without moving parts. Among them, a classifier without a movable part includes a fixed wall centrifugal classifier and an inertial force classifier. Loffier. F. and K. Maly: Symposium on Powde
An elbow jet classifier that is commercialized as Nippon Steel Mining as exemplified in r Technology D-2 (1981),
Okuda.S.and Yasukuni. J.:Proc.Inter.Symposium on
A classifier exemplified by Powder Technology '81, 771 (1981) has been specifically proposed.

Generally, many different properties are required for a toner, and in order to obtain a product satisfying all the required properties, the properties of the toner are determined not only by selection of raw materials to be used but also by a manufacturing method. Often. Because of this,
For example, in a toner classification process, it is required that the toner particles obtained by the classification have a sharp particle size distribution. Further, in the production of toner, it is desired to efficiently and stably produce high quality toner at low cost. Further, in recent years, toner particles used have been gradually shifted to finer sizes in order to improve image quality in copying machines and printers. In contrast, in general, the function of the interparticle force increases as the material becomes finer, but the same applies to resin particles and toner particles. Difficult problems arise.

In particular, when trying to obtain a toner having a sharp particle size distribution having a weight average particle size of 10 μm or less, there is a problem that the classification yield is reduced by the conventional classification apparatus and classification method. Further, the weight average particle size is 8
When a toner having a sharp particle size distribution of not more than μm is to be obtained, the classification yield is remarkably reduced particularly with the conventional classification apparatus and classification method. Further, even if a desired product comprising fine particles having a fine particle size distribution can be obtained by the conventional method, the process becomes complicated, the classification yield is reduced, the production efficiency is poor, and the cost is high. That is inevitable. This tendency becomes more pronounced as the desired particle size of the product becomes smaller.

JP-A-63-101858 (corresponding to US Pat. No. 4,844,349) discloses a first classifier,
A toner production method and apparatus using a pulverizing means and a multi-divided classifying means as a second classifying means following the pulverizing means have been proposed but are not sufficient, and a toner having a weight average particle diameter of 8 μm or less can be more stably and efficiently used. There is a long-felt need for a method and apparatus system for manufacturing.

[0015]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method of manufacturing a toner for developing an electrostatic image, which solves the above-mentioned various problems in the prior art. . That is, an object of the present invention is to provide a manufacturing method capable of efficiently manufacturing a toner for developing an electrostatic image, and efficiently manufacturing a toner for developing an electrostatic image having a small particle size having a fine particle size distribution. An object of the present invention is to provide a manufacturing method. Further, the present invention is a method for melt-kneading a mixture containing a binder resin, a colorant and an additive, and after cooling the melt-kneaded product, a fine predetermined material from a powder raw material composed of solid particles formed by coarse pulverization. It is an object of the present invention to provide a method capable of efficiently producing small-sized particle products (used as toner) having a particle size distribution with high yield. In particular, it is an object of the present invention to obtain a toner having a sharp particle size distribution from a toner raw material having a weight average particle diameter of 10 μm or less, and in particular, from a toner raw material having a weight average particle diameter of 8 μm or less. An object of the present invention is to provide a toner manufacturing method capable of efficiently manufacturing a toner for developing an electrostatic image having a cloth .

[0016]

The above object is achieved by the present invention described below. That is, the present invention relates to a method comprising melt-kneading a mixture containing at least a binder resin and a colorant, cooling the resulting kneaded product, and then pulverizing the cooled product by a pulverizing means to obtain a coarsely pulverized product. First, the body material
Introduced into the classification step to classify the first fine powder and the first coarse powder, then the classified first fine powder is used as a classified product for producing a toner, and the first classified powder is classified in the first classification step. the coarse powder as grinding object, and a grinding chamber for finely grinding the acceleration tube and the object to be crushed for conveying accelerate grinding object by (i) a high pressure gas, to (ii) the grinding chamber A collision member having a collision surface provided opposite to the opening surface of the outlet of the acceleration tube is provided,
(Iii) The inner wall of the accelerating tube throat and the high-pressure gas injection
Formed between the outer wall of the nozzle exit has a grinding object supply opening for supplying the acceleration tube of the grinding object, and (iv) the impact surface is protruding central portion which central protrudes, its Having a shape consisting of a cone-shaped outer peripheral collision surface provided on the outer periphery,
(V) Further, in the above-mentioned pulverizing chamber, the object to be pulverized by the collision member is introduced into a collision-type airflow pulverizer having a side wall for further pulverizing by collision, and then pulverized, and then pulverized. The material is introduced into a third classifying step using a classifier that classifies the powder using centrifugal force generated by a forced vortex, and is classified into a second coarse powder and a second fine powder. A method for producing a toner, characterized in that coarse powder is mixed with the powder raw material, re-introduced into the first classification step, and circulated.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of 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. As shown in the flowchart, the manufacturing method of the present invention has first, second and third classification steps. That is, a mixture containing at least a binder resin and a colorant, which are toner materials, is melt-kneaded. First, a predetermined amount of the powder raw material is supplied to the first classification step. In the first classifying step, preferably, a classifier such as a rotary airflow classifier that classifies by a centrifugal force using a forced vortex is used as the first classifying means, and the powder material is converted into the first coarse powder and the first fine powder. And classify.

The first coarse powder classified in the first classification step is introduced into a specific impingement-type airflow fine pulverizer having excellent pulverization performance and pulverized. Then, the finely pulverized material is introduced into a third classifying step to classify into a second coarse powder and a second fine powder, and in this step, a group of particles (ultrafine powder) smaller than a specified particle size is removed. As a classification means in the third classification step, a classifier that classifies the powder using centrifugal force generated by forced vortex is used. The second coarse powder classified in the third classification step is
It is mixed into the powder raw material introduced into the first classification step, and is again supplied to the first classification step and circulated. In the second coarse powder, the ultrafine powder is classified and removed, and since the ultrafine powder is not contained, the classification efficiency of the first classification step and the subsequent second classification step is improved, Further, it is possible to suppress over-pulverization by a pulverizer following the first classification step.

As shown in FIG. 1, the first fine powder classified in the first classification step is introduced into a second classification means in the second classification step, and further classified, and is classified from particles having a specified particle size. To obtain a classified product as a toner raw material. On this occasion,
In the second classification step, the second classifying means, at least coarse powder region, a multi-division classifier having a medium powder region and a fine powder region Ru is preferably used et. For example, when a three-division classifier is used, the powder raw material is classified into at least three types: fine powder, medium powder, and coarse powder. In the second classifying step using such a classifier, a coarse powder consisting of a group of particles having a particle size larger than a specified particle size and an ultrafine powder consisting of a group of particles having a particle size smaller than the specified particle size are removed. The toner product is used as it is or after being mixed with an external additive such as hydrophobic colloidal silica. In the present invention, in the powder raw material introduced into the second classification step, a particle group (ultrafine powder) having a particle size smaller than a specified particle size is removed by a third classification step, and a particle group having a particle size equal to or larger than a specified particle size in the first classification step. (Coarse particles)
Because of having a sharp particle size distribution from which
In the second classification step, fine classification in a small particle size region of 8 μm or less becomes possible.

The ultrafine powder composed of particles having a particle size smaller than the specified particle size classified in the second classification step and the third classification step generally comprises a toner material introduced into the first classification step. It is supplied to a melt-kneading process for producing a powder raw material and is reused or discarded.

As described above, in the method for producing a toner of the present invention, coarse particles are separated from the powder raw material by performing classification using a classifier capable of fine classification without causing aggregation of particles in the fine particle region. A first classifying step for removing, a pulverizing step for efficiently pulverizing the coarse particles, and a subsequent classifying apparatus for classifying the finely pulverized material efficiently by a classifier for classifying the powder using centrifugal force generated by forced vortex. A third classifying step of reliably removing the ultrafine powder and a second classifying step of performing fine classification in the fine particle region, a coarse powder larger than a specified particle size including agglomeration of ultrafine particles, and An ultrafine powder having a particle size less than a specified particle size including a fine powder generated by agglomeration is surely removed.
m and a classified product having a small particle size and a sharp particle size distribution can be efficiently obtained. As a result,
Efficient production of high quality toner products becomes possible.

FIG. 2 shows an example of an apparatus system to which the method for producing a toner of the present invention is applied, and the present invention will be described more specifically based on this. To a powder raw material which is a toner raw material introduced into this apparatus system, a mixture containing at least a binder resin and a colorant is melt-kneaded, the obtained kneaded material is cooled, and the cooled material is further coarsely crushed by a crushing means. A crushed one is used. The toner material and the like used at that time will be described later.

In the method for producing a toner according to the present invention, a powdery raw material of a toner comprising the above-mentioned coarsely pulverized material is firstly used.
A predetermined amount is introduced into a first classifier 22 via a first fixed amount feeder 21, and the first classifier 22 classifies the first fine powder and the first coarse powder. The first fine powder classified here is sent to a second quantitative feeder 24 through a collection cyclone 23, and then through a vibrating feeder 25, and further into a fine powder supply nozzle 1.
A predetermined amount is supplied to the multi-segmentation classifier 27 which is the second classifier via 48 and 149.

Next, a multi-divider classifier 27 (3 in the example shown in FIG.
The first fine powder introduced into the divided classifier is classified by the classifier 27 into at least a fine powder, a medium powder and a coarse powder. The classified coarse powder is collected by a collection cyclone 29 and then introduced again into the pulverizer 28 in the example shown in FIG. However, it is not limited to this,
At this time, the coarse powder may be introduced into the first classifier 22.
The fine powder composed of a group of particles smaller than the specified particle size classified by the second classification means 27 is collected by the collection cyclone 30 and supplied to a melt-kneading process for producing a powder material composed of a toner material. Used or discarded. The intermediate powder classified by the second classification means 27 is collected by the collection cyclone 31 to be used as a toner product 33.

On the other hand, the first coarse powder classified by the first classifier 22 is sent to the impingement type air flow fine pulverizer 28 and pulverized, and then the fine pulverized material 3 is introduced into the third classifier 1. Being second
Classified into fine powder 5 and second coarse powder 4. The second fine powder 5 composed of a group of particles smaller than the specified particle size classified by the third classifier 1
The toner is collected through the collecting cyclone 2 and supplied to a melt-kneading process for producing a powder material composed of a toner material, and is reused or discarded. In addition, the second coarse powder 4 classified by the third classifier 1 from which particles having a particle size smaller than the specified particle size have been removed is mixed into a newly charged powder raw material, and is again mixed with the powder raw material in the first classifier. It is introduced to 22 and classified.

In an apparatus system to which the toner manufacturing method of the present invention is applied, as a third classifying means, a classifier for classifying powder using centrifugal force generated by a forced vortex as illustrated in FIG. Is used. Less than,
The airflow classifier 1 illustrated in FIG. 5 will be described.

In FIG. 5, reference numeral 14 denotes a cylindrical main body casing of the airflow classifier 1, and a classification chamber 7 is formed inside the main body casing 14 through a guide chamber 17, and the classification is performed. A coarse powder discharging hopper 13 is connected to a lower portion of the chamber.

The classifier illustrated in FIG. 5 is of an individual drive type, and classifies the powder into a second coarse powder and a second fine powder by using a centrifugal force generated by a forced vortex in the classification chamber 7. That is,
A classifying rotor 8 is provided in the classifying chamber 7, and the material to be classified (pulverized material) and air sent from the guide chamber 17 are swirled into the classifying chamber 7 from between the classifying rotors 8. Is flowed in. At this time, the raw material to be classified is charged from the finely pulverized material input port 16 and air is supplied from the secondary air input port 1.
1, 12, and further, are taken in from the finely pulverized material inlet 16 together with the raw materials to be classified. The material to be classified is conveyed into the classification chamber 7 together with the inflow air from the impinging airflow pulverizer. FIG.
In order to perform accurate classification in the airflow classifier as shown in FIG.
It is preferable that the air flowing through the inside 7 and the finely pulverized material as the raw material to be classified are uniformly distributed between the respective classification rotors 8. For this reason, it is necessary to make the flow path leading to the classification rotor 8 into a shape in which concentration of the material to be classified hardly occurs. In the present invention, for example, the raw material straightening plate 15 having a shape as shown in FIG. And pulverized material input port 1
6 is preferably installed in a flow path until the finely pulverized material reaches the inside of the classification chamber 7.

The classifying rotor 8 in the classifying chamber 7 constituting the airflow classifier shown in FIG. 5 is movable, and the distance between the classifying rotors 8 can be adjusted appropriately. Furthermore,
The speed of the classifying rotor 8 is controlled through the frequency converter 20, and the speed can be appropriately controlled depending on the kind of the material to be classified and the like. The second fine powder classified as described above is discharged from the fine powder discharge pipe 9 shown in FIG. Since the fine powder discharge pipe 9 is connected to the suction fan 19 via the fine powder collecting means 18 such as a cyclone or a dust collector, the suction fan 19 is operated to apply a suction force to the classification chamber 7. You.

The air-flow classifier which classifies powder by centrifugal force using forced vortex, which is preferably used as the third classification means, has the above-mentioned structure, and is a finely pulverized material pulverized by the above-mentioned collision type air-flow pulverizer. And the air used for the pulverization are supplied into the guide chamber 17 from the finely pulverized material input port 16, and the air containing the finely pulverized material passes through the guide chamber 17 and between the blades of each classifying rotor 8. Inflow.

The finely pulverized material flowing into the classifying chamber 7 is dispersed by the classifying rotor 8 rotating at a high speed, and centrifuged into a second coarse powder and a second fine powder by centrifugal force acting on each particle. Then, the second coarse powder in the classification chamber 7 passes through the coarse powder discharge hopper 13 connected to the lower part of the main casing 14 and is again supplied to the first classification means to be circulated.

According to the classifier having the above configuration shown in FIG. 5 used as the third classifying means, the flow path until the finely pulverized material reaches the inside of the classifying chamber 7 has a shape as shown in the figure. A raw material flow straightening plate 15 having fine particles and a finely pulverized material input port 16 are provided. Since it can fly with force, the dispersion of the finely pulverized material in the classification region can be improved. Especially in fine powder,
Good classification accuracy is obtained even at a higher dust concentration, and an ultrafine powder having a cohesive property (weight average particle size of 2 μm or less) can be reliably excluded from the finely pulverized material. As a result, since these ultrafine powders are not introduced into the subsequent processes, not only can the yield of the final product be prevented from lowering, but also the same dust concentration can be obtained during the classification by the second classification means. Thus, it is possible to achieve better classification accuracy and to improve the product yield. That is, this makes it possible to efficiently obtain a product (medium powder) having a sharp particle size distribution by the second classification means.

In the apparatus system to which the method for producing a toner according to the present invention is applied, the pulverizing means provided before the third classifying step as described above includes, for example, FIGS.
And a collision-type airflow pulverizer of the type exemplified in (1). Less than,
These will be described. First, in the collision type air flow fine pulverizer shown in FIG. 6, the pulverized object 42 supplied from the pulverized object supply pipe 41 is supplied to the accelerating pipe throat 44 of the accelerating pipe 43.
Is supplied to the accelerating tube 43 from a pulverized material supply port 46 (also a throat portion) formed between the inner wall of the nozzle and the outer wall of the high-pressure gas ejection nozzle 45. 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, 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 to the acceleration pipe outlet 50. Spouting while expanding rapidly in the direction. At this time, the acceleration tube throat 44
Crushed object 42 due to the ejector effect generated near
Is rapidly accelerated while being uniformly mixed with the high-pressure gas in the accelerating tube throat 44 from the crushed object supply port 46 toward the acceleration tube outlet 50 while being entrained by the gas coexisting with the crushed object 42. . Then, it collides against 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. The impact force generated at the time of the collision is based on the sufficiently dispersed individual particles (objects to be ground 4).
Since it is given in 2), very efficient pulverization can be performed.

The pulverized material pulverized on the collision surface 52 of the collision member 51 is further subjected to 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 discharge port 55. In the collision type air current pulverizer shown in FIG. 6, if the collision surface 52 of the collision member 51 is a collision surface having a conical projection at the center as shown in FIGS. In this case, the pulverized material is uniformly dispersed, and the high-order collision with the side wall 54 can be efficiently performed. Furthermore, when the pulverized material discharge port 55 is located behind the collision member 51, the pulverized material can be smoothly discharged.

That is, as shown in FIG. 7, by providing a cone-shaped central protruding portion whose central portion protrudes on the raw material collision surface 52 of the collision member 51, The solid-gas mixed flow of the compressed air and the compressed air is first pulverized on the collision surface 52 of the projection surface of the collision member 51, and further pulverized on the conical collision surface 52 ′ provided on the outer periphery thereof. Tertiary grinding is performed on the side wall 54. At this time, the apex angle α formed by the collision surface 52 at the center of the projection surface of the collision member 51
When (°) and the inclination angle β (°) of the outer peripheral collision surface 52 ′ and the central axis of the accelerating tube with respect to the vertical plane satisfy the following relationship, grinding is performed very efficiently. 0 <α <90, β> 0 30 ≦ α + 2β ≦ 90

That is, when α ≧ 90, the central projection surface 5
The reflected flow of the pulverized material primary-pulverized in 2 disturbs the flow of the solid-gas mixed flow ejected from the acceleration tube 43, which is not preferable. When β = 0, the outer peripheral collision surface 52 ′ 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. Disturbance is undesired. 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 fused material and Agglomerates are easily formed. When such a fusion product is generated, stable operation of the apparatus becomes difficult. When α and β are α + 2β <30, the impact force of the primary pulverization on the projection surface 52 is weakened, and the pulverization efficiency is lowered, which is not preferable. When α and β are α + 2β <90, the reflected flow at the outer peripheral collision surface 52 ′ flows downstream of the solid-gas mixed flow, so that the impact force of the tertiary pulverization on the pulverization chamber side wall 54 is weakened, and the pulverization efficiency is reduced. Cause a decline.

As described above, when α and β satisfy the following relationship, primary, secondary, and tertiary pulverization are efficiently performed, and the pulverization efficiency can be improved. 0 <α <90, β> 0 30 ≦ α + 2β ≦ 90 More preferable values of α and β are as follows. 0 <α <80 5 <β <40

In the present invention, the number of collisions can be increased and the effect can be increased by using the above-mentioned collision type airflow pulverizer as compared with the case of using the conventional airflow pulverizer as shown in FIG. As a result, it is possible to improve the pulverization efficiency, to prevent the occurrence of fused material on the collision surface and the like during the pulverization, and to perform a stable operation. FIG. 8 is an enlarged view of a pulverizing chamber 53 in the impingement type air current pulverizer shown in FIG. In FIG. 8, the closest distance L ₁ between the edge 61 and the side wall 54 of the collision member 51 is
It is shorter than the closest distance L ₂ between the front wall 62 of the grinding chamber facing the impact surface 52 and 52 'and the edge portion 61 of the impact member 51, dust concentration of pulverizing chamber in the vicinity of the accelerating tube outlet 50 It is important to keep the price high. Furthermore, the closest 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 side wall 54.

A crusher as shown in FIG. 6 having the inclined collision surfaces 52 and 52 ′ as described above has a collision surface 166 as shown in FIG. Compared to a conventional crusher having a collision member 164
In the case of pulverizing a resin or a sticky substance, the object to be pulverized is unlikely to cause fusion, agglomeration, and coarsening, and can be pulverized at a high dust concentration. In addition, wear is not locally concentrated, and the life of the device is prolonged, so that stable operation is possible.

If the inclination of the acceleration tube 43 shown in FIG. 6 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 supplied to the crushed material supply port 46. It is possible to process without blocking. When the fluidity of the crushed material 42 is not good, when a cone-shaped member is provided below the crushed material supply pipe 41 as shown in FIG. Crushed material 42
But the inclination of the acceleration tube 43 is set to 0 ° to 20 ° (more preferably 0 ° to 5 °) with respect to the vertical direction.
Within this range, the material to be ground 42 can be smoothly supplied to the acceleration tube 43 without stagnation of the material to be ground at the lower part of the cone-shaped member.

FIG. 9 is a sectional view taken along the line AA 'in FIG. From FIG. 9, it is understood that the object to be ground 42 is smoothly supplied to the acceleration tube 43. The front wall 62 at the plane of the acceleration tube outlet 50 that intersects perpendicularly with the extension of the central axis of the acceleration tube 43
The closest distance L ₂ between the collision member 51 and the outermost end 61 of the collision surface 52 of the collision member 51 facing the collision member 51 is the diameter R of the collision member 51.
It is preferable in terms of pulverization efficiency to be in the range of 0.2 to 2.5 times the above, and more preferable in the range of 0.4 to 1.0 time. The distance L in the _two is less than 0.2 times the diameter of the impact member 51, not preferred may have dust concentration of the impact surface 52 near becomes too Also, when it exceeds 2.5 times, the impact force is weakened As a result, the pulverization efficiency tends to decrease, which is not preferable.

The outermost end 61 and the side wall 54 of the collision member 51
The shortest distance L ₁ between is preferably in the range 0.1 times to 2 times the diameter R of the collision member 51. In the distance L ₁ is less than 0.1 times the diameter R of the collision 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, 2 If it exceeds twice, the effect of the secondary collision of the material to be ground on the side wall 54 of the grinding chamber is reduced, and the efficiency of the grinding tends to decrease, which is not preferable. More specifically, the length of the acceleration tube 43 is 50 to 5
The diameter R of the collision member 51 is preferably 30 mm to 300 mm.
Furthermore, the collision surfaces 52, 52 'of the collision member 51 and the side wall 54
Is preferably formed of ceramic from the viewpoint of durability.

FIG. 10 is a sectional view taken along the line BB 'in FIG. In FIG. 10, 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 the accelerating tube 4.
The larger the inclination of 3 with respect to the vertical direction, the more uneven the distribution of the flowing particles. For this reason, the inclination of the acceleration tube 43 is most preferably in the range of 0 ° to 5 °. This was confirmed in an experiment using a transparent acrylic resin internal observation acceleration tube as the acceleration tube 43.

FIG. 11 is a sectional view taken along the line CC 'in FIG. In FIG. 11, the object 42 to be ground is the collision member support 9.
It is discharged backward through the space between the first and side walls 54. FIG.
Shows a DD ′ cross-sectional view in FIG. In FIG. 12, two high-pressure gas introduction pipes 92 are provided. However, depending on the case, the number of high-pressure gas introduction pipes 92 may be one or three or more.

FIG. 13 is a schematic view showing another specific example of the collision type air flow pulverizer preferably used in the present invention. In FIG. 13, the same numbers as those in FIG. 6 indicate the same members. In the collision type air current pulverizer shown in FIG. 13, the acceleration tube 43 has a long axis inclination of 0 ° to 45 ° with respect to a vertical line.
°, preferably 0 ° to 20 °, more preferably 0 ° to 5 °
The grinding target 42 is supplied to the accelerating tube 43 from the grinding target supply port 46. At this time, the acceleration tube 43
Compressed gas such as compressed air is supplied to the high pressure gas supply port 102.
And the throat section 44 through the high pressure gas chamber 103
The crushed object 42 supplied to the accelerating tube 43 is instantaneously accelerated to have a high speed. The crushed material 42 jetted into the crushing chamber 53 from the acceleration tube outlet 50 at a high speed is applied to the colliding surfaces 52 and 5 of the colliding member 51.
It crushes by collision with 2 '.

As described above, in the pulverizer shown in FIG.
The crushing efficiency is improved more than before by dispersing the crushed material 42 in 3 and uniformly squirting the crushed material from the acceleration tube outlet 50 to collide with the collision surface 52 of the opposing collision member 51 efficiently. Can be done. Also, the collision surface 5 of the collision member 51
When 2 and 52 ′ have a shape having conical projections on the collision surface as shown in FIG. 13 and FIG. 7, dispersion after collision is also good, and fusion, aggregation, and Coarsening does not occur, it is possible to pulverize at a high dust concentration, and in the abradable material 42, the abrasion generated on the inner wall of the accelerating tube 43 and the collision surface of the collision member 51 is locally generated. It is possible to extend the service life and achieve stable operation without concentration.

As in the case of the pulverizer shown in FIG.
If the inclination in the long axis direction of 3 is in the range of 0 ° to 45 °, the material to be ground 42 can be processed without being blocked at the material supply port 46, but the fluidity of the material to be ground 42 is not good. Has a tendency to stay in the lower part of the pulverized material supply pipe 41, but if the inclination of the accelerating pipe 43 is in the range of 0 ° to 20 °, more preferably 0 ° to 5 °, the The material to be crushed 42 is smoothly supplied into the acceleration tube 43 without stagnation.

The sectional view taken along the line CC ′ in FIG. 13 is the same as the sectional view taken along the line CC ′ in FIG. It is discharged backward through.

[0050] The first toner used in the toner production method of the present invention
Any of the first classifying means in the classifying process
Can be used, but it is preferable to use a forced vortex
Use a rotary airflow classifier that classifies by heart force. this
For example, T-shirts manufactured by Hosokawa Micron Corporation
-Plex (ATP) classifier and micron separator
ー, Donaldelec classifier manufactured by Donaldson Japan, Nisshin
And a turbo classifier classifier manufactured by Kosha Co., Ltd. Book
In the present invention, preferably, a configuration as shown in FIG.
The use of a rotary air classifier of the type
Desirable to improve class accuracy. Hereinafter, shown in FIG.
The rotary air classifier will be described in detail.

In FIG. 14, reference numeral 121 denotes a cylindrical main body casing. A classification chamber 122 is formed inside the main body casing 121, and a guide chamber 123 is provided below the classification chamber 122. The rotary airflow classifier shown in FIG. 14 is of an individual drive type, and generates a forced vortex using centrifugal force in the classifying chamber 122 to classify it into coarse powder and fine powder. A classifying rotor 124 is provided in the classifying chamber 122, and the powder raw material 42 and the air fed into the guide chamber 123 are swirled into the classifying chamber 122 by suction from between the classifying rotors 124. The powder raw material 42 is supplied from a raw material input port 125, and air is supplied from an input port 126,
Further, it is taken in together with the powder raw material 42 from the raw material input port 125. The powder raw material 42 is supplied to the classification chamber 12 together with the incoming air.
It is carried to 2. It should be noted that the guide room 123 passes through the input port 125.
It is preferable to uniformly distribute the air flowing through the inside and the powder material 42 to the respective classification rotors 124 in order to accurately classify the powder. Further, it is necessary that the flow path to reach the classification rotor 124 has a shape in which concentration hardly occurs. However, the position of the inlet 125 is not limited to this.

The classifying rotor 124 is movable, and the interval between the classifying rotors 124 can be arbitrarily adjusted. The speed control of the classifying rotor 124 is performed through a frequency converter 128. Fine powder discharge pipe 129
Is connected to a suction fan 131 via fine powder collecting means 130 such as a cyclone or a dust collector.
By actuating 31, a suction force is applied to the classifying chamber 122.

The rotary airflow classifier shown in FIG. 14, which is preferably used as the first classifier in the present invention, has the above-described structure, but is classified by the airflow classifier 1 as shown in FIG. The supplied coarse powder (second coarse powder), the air used for classification and the air containing the newly supplied powder raw material 42 are supplied into the guide chamber 123 from the input port 125, and these powder materials are discharged. The contained air flows from the guide room 123 to between the classifying rotors 124. The powder raw material that has flowed into the classification chamber 122 is supplied to the classification rotor 12 that rotates at a high speed.
4 and is centrifuged into a first coarse powder and a first fine powder by centrifugal force acting on each particle. Then, the first coarse powder in the classifying chamber 122 passes through a coarse powder discharging hopper 132 connected to the lower part of the main body casing 121, and passes through a rotary valve 133 as shown in FIG. Object supply pipe 41 of simple collision type air current crusher 28
Supplied to Further, the first fine powder is discharged to the fine powder collecting means 130 by the fine powder discharge pipe 129 and then introduced into the second classifying means.

In the present invention, as shown in FIG. 2, in the first classifying step, a rotary air classifier having the structure shown in FIG. 14 as described above is used, and the pulverizing means in the subsequent pulverizing step is used. A collision type air flow pulverizer as shown in FIG. 6 or FIG. 13 is used, and furthermore, an inclined classifying plate provided at the bottom of the classifying chamber with a raised central portion, and a swirling flow in the classifying chamber are generated. Classifying louver for classifying the finely pulverized material with a classifier that swirls and flows the powder particles by an air flow that flows into the classifying chamber through the classifying louver and centrifugally separates the powder to classify the powder. By combining the third classifying step of removing the ultrafine powder by mixing, the mixing of the ultrafine powder into the pulverizer is favorably suppressed or prevented, and the pulverized material is prevented from being excessively pulverized. The classified coarse powder is smoothly supplied to the crusher. Further uniformly dispersed to the accelerating tube mills, since it is well ground in the grinding chamber of the grinder, it is possible to increase the energy efficiency of yield and per unit weight of the pulverized product obtained.

In the rotary airflow classifier used for the first classifying means as described above, the classification point is determined by the number of revolutions of the classifying rotor, but conventionally, the efficiency of the pulverizing means connected thereto is not good. Therefore, it is difficult to obtain a toner having a small diameter as a classified product, and even if it is obtained, it requires a great deal of labor. However, in the present invention, the performance of the crushing means can be improved because the impingement airflow crusher shown in FIG. 6 or FIG. 13 is used, and the coarse powder classified by the first classifying means is further finely divided. Is efficiently performed, and the ultrafine powder having a particle size smaller than the specified particle size is removed in the third classification step. Furthermore,
When a rotary classifier is used as the first classifying means, the classifying point can be easily changed only by changing the number of revolutions of the classifying rotor, so that there is an advantage that operability is excellent.

At least a coarse powder region (first fractionation region), a medium powder region (second fractionation region) and a fine powder region (third fraction) which can be used in the second classification step constituting the toner production method of the present invention. As a second classifying means for providing a multi-segmented classification area of a (segmentation area), for example, a multi-segmentation classifier of the type shown in FIG. The classifying chamber having such a classifying area is mainly composed of side walls 141 and 142 and lower walls 143 and 14 having a shape as shown in FIG.
4 and a Coanda block 145. Lower wall 14
3 and 144 have knife-edge classification edges 146 and 147, respectively, by which the classification zone is divided into three. Side wall 1
At the lower part of 41, there are provided raw material supply pipes 148 and 149 which open to the classification chamber, and a Coanda block 145 which is bent downward with respect to the extension direction of the bottom tangent of the supply pipe to draw an elliptical arc is provided. . Also, the upper wall 150 of the classification room
Has a knife-edge type inlet edge 151 directed toward the lower part of the classifying chamber, and further, at the upper part of the classifying chamber, there are provided air inlet pipes 152 and 153 opening to the classifying chamber. In addition, gas introduction adjusting means 154 and 155 such as a damper, and static pressure gauges 156 and 157 are provided in the intake pipes 152 and 153.
Is provided. The positions of the classification edges 146 and 147 and the inlet edge 151 differ depending on the type of the raw material to be classified and the desired particle size. Further, discharge ports 158, 159, and 160 are provided on the bottom of the classification chamber so as to open into the classification chamber corresponding to the respective separation areas. Outlet 1
Each of 58, 159 and 160 may be provided with an opening / closing means such as a valve means.

The raw material supply pipe is preferably composed of a cylindrical raw material supply pipe 148 and a pyramid-shaped cylindrical raw material supply pipe 149, and the inner diameter of the raw material supply pipe 148 and the narrowest part of the raw material supply pipe 149. When the ratio of the inner diameters is set to 20: 1 to 1: 1, preferably 10: 1 to 2: 1, a good insertion speed can be obtained. As a means for introducing the powdery raw material to be classified into the supply pipe together with the air flow, a method of applying a pressure of 0.1 to 3 kg / cm ² and feeding the same, a blower located downstream of the classification zone is enlarged, and A method of naturally aspirating the outside air and the powder raw material by increasing the pressure, or a method of attaching an injection feeder to the raw material powder input port, thereby sucking the raw material powder and the outside air and sending it to the classification zone via a supply pipe. Etc.

In the present invention, among the above-mentioned charging means,
Particularly, it is advantageous and preferable to use a method in which the negative pressure in the classification zone is increased and the outside air and the powder raw material are naturally sucked, or a method using an injection feeder is used in terms of the apparatus and operating conditions. Further, the classification of the toner for developing an electrostatic image, which requires high-precision classification, can be performed more effectively. Further, in the classification of the toner having a weight average particle diameter of 10 μm or less, a favorable effect can be obtained. In particular, in the classification of toner having a weight average particle diameter of 8 μm or less,
Further effects can be obtained.

The classification operation in the multi-division classification region having the above configuration is performed, for example, as follows. That is, the pressure in the classification area is reduced through at least one of the outlets 158, 159, and 160, and the raw material powder is supplied to the raw material supply pipes 148 and 149 at a flow rate of 50 m / sec to 300 m / sec by an air flow flowing by the reduced pressure. To the classification area via
That is, if the first fine powder is supplied to the classification area at a flow rate of less than 50 m / sec, it is difficult to sufficiently loosen the aggregation of the fine powder, and it is easy to cause a decrease in classification yield and classification accuracy.
Not preferred. When the first fine powder is supplied to the classification region at a flow rate exceeding 300 m / sec, the particles tend to be crushed due to the collision of the particles and ultrafine particles are easily generated, which tends to cause a decrease in the classification yield, and is thus preferable. Absent.

By the means described above, the powder material composed of the first fine powder supplied in the first classification step is supplied with the Coanda effect by the action of the Coanda block 145 and the action of gas such as air flowing in at that time. In accordance with the size of each particle size, large particles (particles having a particle size exceeding the standard particle size) move outside the airflow, that is, the first fractionation area outside the classification edge 147. In the meantime, the intermediate particles (particles within the standard size) are the second particles between the classification edges 146 and 147.
In the fractionation area, small particles (particles smaller than the standard particle size) are respectively divided into a third fractionation area inside the classification edge 146, and large particles (coarse powder) are discharged from the outlet 158 to intermediate particles (medium). Powder) is small particles (fine powder) from outlet 159
Are discharged from the discharge port 160 respectively.

In order to carry out the above-described method, the above-described devices are connected to each other by a communication means such as a pipe, and for example, an integrated device system as shown in FIG. 2 is used. That is, the multi-segmentation classifier 27 in the integrated device system shown in FIG. 2 is as shown in FIG. 16, and the vibration feeder 25, the collection cyclone 29,
30 and 31 are connected by communication means.

FIG. 3 shows an example of an integrated device system in which the injection feeder 32 is attached to the raw material powder supply nozzle portion of the above-mentioned multi-divider classifier preferably used in the present invention. Examples of the multi-segment classifier 27 as the second classifier include a classifier using the Coanda effect having a Coanda block such as an elbow jet manufactured by Nippon Steel Mining Co., Ltd. In this system, the powdery raw material of the toner is first introduced into the first classifier 22 via the first metering device 21 and classified. The fine powder classified by the first classifier 22 is collected by a collecting cyclone 23.
Through the vibratory feeder 25 and then into the fine powder supply nozzles 148 and 14
9 and is introduced into a multi-segmentation classifier 27 as shown in FIG. At this time, if high-pressure gas is supplied from the injection feeder 32 of the raw material powder supply nozzle portion, the individual particles of the raw material powder can be dispersed and introduced into the multi-divided classifier 27 while having a propulsive force, and the suction shown in FIG. This is more preferable because the classification accuracy can be improved as compared with the method of performing the above. On the other hand, the coarse powder classified by the first classifier 22 is sent to the pulverizer 28, and after being pulverized, together with the newly input pulverized raw material,
It is again introduced into the first classifier 22 and the above classification process is performed.

For introduction into the multi-segmentation classifier 27,
The powder raw material is introduced into the three-division classifier 27 at a flow rate of 50 m / sec to 300 m / sec. The size of the classification area of the multi-segment classifier 27 is usually (10 to 50 cm) × (10 to 5 cm).
0 cm), the pulverized material can be classified into three or more particle groups in 0.1 to 0.01 seconds. The three-divided classifier 27 separates large particles (particles exceeding a specified particle diameter: coarse powder), intermediate particles (particles having a specified inner particle diameter: medium powder), and small particles (particles smaller than the specified particle diameter). : Fine powder). Thereafter, the coarse powder is sent to the collection cyclone 29 through the discharge conduit 158 and returned to the pulverizer 28. The intermediate powder is discharged out of the system via a discharge conduit 159, collected by the collection cyclone 31, and collected as a toner product 33. The fine powder is discharged out of the system via the discharge conduit 160, collected by the collection cyclone 30, and then collected as the fine powder 34 having an irregular particle diameter. In addition, collection cyclone 2
9, 30, and 31 are used to feed the pulverized raw materials to the nozzles 148 and 14
It can also function as a suction pressure reducing means for sucking and introducing the classification area via 9. In addition, the coarse powder classified at this time may be returned to the pulverizer 28 or may be returned to the first constant-rate feeder 21. In order to reduce the load on the first classifier 22 and reliably perform the pulverization by the pulverizer 28, it is more preferable to return the coarse powder directly to the pulverizer 28.

In the present invention, the first classifying step and the pulverizing step shown in the flowchart of FIG. 1 are not limited to the examples described above. For example, one pulverizing means and one first classifying means are used. Two or two or more pulverizing means and first classifying means may be provided. What kind of combination constitutes the pulverizing step may be appropriately set depending on a desired particle diameter, a constituent material of toner particles, and the like. In this case, where the coarse powder to be returned to the pulverizing step is to be returned may be appropriately set. Further, the multi-divider classifier as the second classifier is not limited to the one shown in FIG.
What is necessary is just to employ | adopt the thing of an optimal shape by the particle diameter of the powder raw material introduce | transduced into a multi-divided classifier, the desired medium powder, and the true specific gravity of a powder. In the present invention, the particle size of the powdery raw material composed of the coarsely pulverized material to be introduced into the first classifying means is 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 the conventional pulverization-classification method using a classifier for removing only the fine particles as shown in the flowchart of FIG. 17 as the second classification means, a certain regulation is applied to the particle size of the powder at the end of the pulverization. It has been required that a coarse particle group having a particle size or more is completely removed. For this reason, a pulverizing capacity more than necessary is required in the pulverizing step, and as a result, excessive pulverization is caused, and the pulverization efficiency is reduced. This phenomenon becomes more conspicuous as the particle size of the powder becomes smaller. In particular, when a medium powder having a weight average particle size of 3 to 10 μm is obtained, the efficiency is significantly reduced.

On the other hand, in the toner production method of the present invention, a multi-divided classifying means is used in the second classifying step, whereby a group of coarse powder particles larger than the specified particle size and a group of fine powder particles smaller than the specified particle size are simultaneously formed. In order to remove it, even if coarse particles exceeding a certain specified particle size are contained in a certain ratio in the particle size of the powder raw material introduced into the second classification step, it is satisfactorily removed by the multi-division classification means in the second classification step. The second
Restrictions in the pulverizing step, which is a pre-stage of the classification step, are reduced, and the ability of the pulverizer can be maximized, so that the pulverizing 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 the purpose of classification into medium powder and fine powder, agglomeration of ultrafine particles which causes fogging of a developed image is liable to occur due to long residence time at the time of classification.
When aggregates are formed, it is generally difficult to remove the aggregates from the medium powder. On the other hand, according to the toner manufacturing method of the present invention, even if the agglomerate is mixed into the powdery raw material that is the raw material to be classified, the agglomerate is produced by the Coanda effect of the multi-divided classifier and / or the impact accompanying the high-speed movement. In addition to being crushed and removed as fine powder, even if there is agglomerates that have escaped crushing, they can be classified and removed to a coarse powder region, so that the agglomerates can be removed efficiently.

The toner production method of the present invention can be preferably used for producing toner particles used for developing an electrostatic image. To prepare an electrostatic image developing toner, a mixture containing at least a binder resin and a colorant is used as a material, and in addition, a magnetic powder, a charge control agent, and other additives, if necessary, are used. Used.
As the binder resin, vinyl-based and non-vinyl-based thermoplastic resins are preferably used. These materials were sufficiently mixed by a mixer such as a Henschel mixer or a ball mill, and then melted, kneaded and kneaded using a hot kneader such as a roll, kneader, and extruder to make the resins compatible with each other. The toner can be obtained by dispersing or dissolving the pigment or dye therein, solidifying it by cooling, and then performing pulverization and classification. Use the system.

Hereinafter, the constituent materials of the toner will be described. When a heat and pressure fixing device or a heat and pressure 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. For example, polystyrene, poly-p
A homopolymer of styrene such as chlorostyrene and polyvinyltoluene and a substituted product thereof; a styrene-p-chlorostyrene copolymer, a styrene-vinyltoluene copolymer, a styrene-vinylnaphthalene copolymer, and a styrene-acrylate ester copolymer. Polymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethacrylic copolymer,
Styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene- Styrene copolymers such as acrylonitrile-indene copolymer; polyvinyl chloride, phenolic resin, natural resin-modified phenolic resin, natural resin-modified maleic acid resin, acrylic resin, methacrylic resin,
Polyvinyl acetate, silicone resin, polyester resin, polyurethane resin, polyamide resin, furan resin,
Epoxy resin, xylene resin, polyvinyl butyral,
Terpene resins, coumaroindene resins, petroleum resins and the like can be mentioned.

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 device, 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 studies conducted by the present inventors, if the content of the magnetic material 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, for example, a crosslinked styrene copolymer or a crosslinked polyester.

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 dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. Monocarboxylic acid having a bond or a substitute thereof; for example, dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like; and a substitute thereof; for example, vinyl chloride, vinyl acetate And 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 like can be used singly 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 or the like; for example, ethylene glycol diacrylate, Ethylene glycol dimethacrylate,
Carboxylic acid esters having two double bonds such as 1,3-butanediol dimethacrylate; for example, divinylaniline, divinylether, divinylsulfide,
A divinyl compound such as divinyl sulfone; a compound having three or more vinyl groups; and the like 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 thereof 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 that a charge control agent is mixed (internally added) to the toner particles before use. The charge control agent makes it possible to control the optimal charge amount according to the development system. In particular, in the present invention, the balance between the particle size distribution and the charge can be further stabilized, and the charge control agent is used. This makes it possible to further clarify the function separation and mutual capture for higher image quality for each particle size range described above. As the positive charge control agent, for example, denatured products such as nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate; Or two or more types can be used in combination. Among them, charge control agents such as nigrosine compounds and quaternary ammonium salts are particularly preferably used. Further, a homopolymer of a monomer represented by the following general formula (1) or a copolymer with a polymerizable monomer such as styrene, acrylate and methacrylate as described above is used as a positive charge control agent. Can be used as
In this case, these charge control agents also function as (all or part of) the binder resin.

General formula (1) R ₁ : H, CH ₃ , R ₂ , R ₃ : a substituted or unsubstituted alkyl group (preferably C
_{1 ~C 4),}

As the negative charge control agent, for example, organometallic complexes and chelate compounds are effective, and examples thereof include aluminum acetylacetonate, iron (II) acetylacetonate, and chromium 3,5-ditert-butylsalicylate. Or zinc or the like, particularly preferably an acetylacetone metal complex, a salicylic acid-based metal complex or a salt thereof, and particularly preferably a salicylic acid-based metal complex or a salicylic acid-based metal salt. The above-mentioned charge control agent (having no action as a binder resin) is preferably used in the form of fine particles.
In this case, the number average particle 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 used as a binder resin 100
0.1 to 20 parts by weight relative to parts by weight (further 0.2 to 1 part by weight)
0 parts by weight).

When the toner is a magnetic toner, examples of the magnetic material contained in the magnetic toner include iron oxides such as magnetite, γ-iron oxide, ferrite, and iron-rich ferrite; and iron, cobalt, and nickel. Metals or alloys of these metals with metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium and mixtures thereof Is mentioned. These ferromagnetic materials have an average particle size of 0.1 to 1 μm, preferably 0.1 to 0.5 μm.
The amount is preferably 60 to 110 parts by weight per 100 parts by weight of the resin component, and more preferably 65 to 10 parts by weight based on 100 parts by weight of the resin component.
0 parts by weight.

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

As described above, according to the present invention,
A toner having a sharp particle size distribution can be obtained from a toner raw material having a weight average particle diameter of 10 μm or less, and a toner having a sharp particle size distribution can be obtained from a toner raw material having a weight average particle diameter of 8 μm or less. .

[0080]

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 (monomer polymerization weight ratio: 80.0 / 19.0 / 1.0, weight average molecular weight = 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 The above formulation was mixed with a Henschel mixer (FM-75).
The mixture was well mixed with a mold and Mitsui Miike Kakoki Co., Ltd.), and then kneaded with a twin-screw kneader (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.) set at a temperature of 150 ° C. The obtained kneaded material was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely pulverized material as a powder raw material for producing a toner.

The obtained toner raw material was finely pulverized and classified by an apparatus system shown in FIG. Collision type air flow crusher 2
Reference numeral 8 denotes an inclination of the acceleration tube in the major axis direction with respect to the vertical line (hereinafter referred to as acceleration tube inclination) using the apparatus having the configuration shown in FIG.
Is about 0 ° (that is, set substantially vertically), and the collision member 51 shown in FIG. 7 was used. This collision member 51
Is α = 55 °, β = 10 °, outer diameter (diameter) 100 mm
The surface of the acceleration tube outlet 50 intersecting at right angles with the acceleration tube central axis shown in FIG.
The shortest distance L ₂ between the first collision surface 52 and the outermost peripheral end 61 is
50 mm, and the shape of the crushing chamber 53 is 150 mm in inner diameter.
Was used. Accordingly, the shortest distance L ₁ between the side wall 54 is 25 mm. As the first classifier 22, a classifier having the configuration shown in FIG. 14 was used. The diameter of the classifying rotor 124 is 200 mm, and the number of revolutions of the classifying rotor is 3000.
Driving at rpm.

In this embodiment, the third classifying means 1 separates the fine powder of the individual drive system of the configuration shown in FIG. An air-flow classifier was used for separation. The diameter of the classifying rotor 8 of the airflow classifier used in this example is 200 mm, and the number of revolutions of the rotor is 5000 rpm. p. m. Driving in such a way. The air-flow classifier communicates the fine powder discharge chute 9 shown in FIG. Was used so as to be introduced again into the first classifier 22.

In the present embodiment, first, the powdery raw material composed of the coarsely pulverized material is converted to 35.0 by the first constant-rate feeder 21 of the table type.
At a rate of kg / h, the mixture was supplied to the rotary airflow classifier 22 having the configuration shown in FIG. The first coarse powder classified by the classifier was introduced into the impinging airflow fine pulverizer 28 having the configuration shown in FIG. The first coarse powder supplied from the crushed object supply pipe 41 of the crusher 28 is first subjected to a pressure of 6.0 kg / cm ² (G),
Finely pulverized using compressed air of 6.0 Nm ³ / min, and the obtained finely pulverized product is introduced into an air flow classifier 1 having a configuration shown in FIG. And a second coarse powder. The second fine powder (ultrafine powder) classified by the airflow classifier 1 is collected and removed by the collection cyclone 2. On the other hand, the fine powder that is classified and discharged through the coarse powder discharge hopper 10 and is the second coarse powder from which the ultrafine powder has been removed is the same as the toner powder raw material supplied in the raw material introduction unit. While mixing, closed-circuit pulverization was performed in which the mixture was again introduced into the airflow classifier 22 and recirculated. The first fine powder classified by the airflow classifier 22 as shown in FIG. 14, which is the first classifying means, is collected by the cyclone 23 while being accompanied by the suction air from the exhaust fan 131, and is collected by the cyclone 23. 24. At this time, the first fine powder had a weight average particle size of 7.1 μm.
m and a sharp particle size distribution substantially free of large particles of 12.7 μm or more.

In the present embodiment, the first fine powder classified by the rotary airflow classifier 22 as the first classifying means is introduced into the second quantitative feeder 24, and the vibrating feeder 25 and the nozzles 148 and 149 are moved. Then, it was introduced into the multi-segmentation classifier 27 having the configuration of FIG. 16 at a rate of 38.0 kg / h. In the classifier 27, the powder is classified into three types of particle sizes of coarse powder, medium powder and fine powder by utilizing the Coanda effect. Multi-division classifier 27
Outlets 158, 159 and 160
The classifying material is separated by using the suction force derived from the pressure reduction in the system by the suction pressure reduction of the collection cyclones 29, 30 and 31 communicating with the source and the compressed air from the injection feeder 32 attached to the material supply nozzle 148. Introduced. The introduced fine powder was instantaneously classified into three types of coarse powder, medium powder and fine powder in 0.1 seconds or less. The coarse powder among the classified ones was collected by a collection cyclone 29, and then re-introduced into the air-flow type fine pulverizer 28 described above.

The obtained intermediate powder had a weight average particle size of 6.8.
Classified product for toner having a sharp particle size distribution containing 19% by number of particles having a particle size of 4.0 μm or less and 1.3% by volume of particles having a particle size of 10.08 μm or more. Had excellent performance. At this time, the ratio of the amount of the finally obtained medium powder to the total amount of the charged powder raw materials (that is, the classification yield) was 82%. When the obtained intermediate powder was observed with an electron microscope, no aggregate of 3 μm or more in which ultrafine particles were aggregated was substantially found.

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 type or Coulter Multisizer II (both manufactured by Coulter Inc.) was used as a measuring device. As the electrolyte solution, about 1% NaCl aqueous solution was prepared using primary sodium chloride, and used, for example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, the electrolyte solution 100 to
In 150 ml, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant, and 2 to 20 mg of a measurement sample is further added. The electrolyte solution in which the sample is suspended is subjected to dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser,
Using the measuring device, the volume and number of the toner were measured using a 100 μm aperture as the aperture, and the volume distribution and the number distribution were calculated. Then, a weight-based weight average particle size determined from the volume distribution according to the present invention was determined.

Example 2 Fine pulverization and classification were carried out in the same apparatus system using the same toner raw material as in Example 1. That is, the impingement type air current pulverizer having the configuration shown in FIG. A multi-segment classifier as the second classifying means had the same configuration as that of the first embodiment shown in FIG. As the first classifying means, a rotary airflow classifier similar to that shown in FIG. 14 was used, but the number of revolutions of the classifying rotor was set to 3400 rpm. Further, as the third classifying means, an air flow classifier similar to that shown in FIG. 5 as in Example 1 was used, and the rotor of the classifier was rotated at 5400 rpm. p.
m. And In this embodiment, the powder raw material is 28.0.
kg / h at a rate of 1 kg / h to the above-mentioned apparatus system.
m was obtained and introduced into the three-divider classifier shown in FIG. 16 at a rate of 30.0 kg / h via the second metering device 24. As a result, the weight average particle size was 6.1 μm.
A medium powder having a sharp particle size distribution containing 26% by number of particles having a particle size of 4.0 μm or less and 0.5% by volume of particles having a particle size of 10.08 μm or more was classified into a classification yield of 79%.
I got it.

Example 3 Fine pulverization and classification were carried out in the same apparatus system using the same toner raw material as in Example 1. That is, the impingement type air current pulverizer having the configuration shown in FIG. A multi-segment classifier as the second classifying means had the same configuration as that of the first embodiment shown in FIG. As the first classifying means, a rotary air classifier similar to that shown in FIG. 14 as in Example 1 was used, but the number of revolutions of the classifying rotor was set at 4200 rpm. Further, as the third classifying means, an air flow classifier similar to that shown in FIG. 5 as in Example 1 was used. p.
m. And In this example, the pulverized raw material was 28.0.
The above system is supplied at a rate of kg / h, and the first and third
5.5 μm weight average particle size by classification and pulverization processes
Was obtained and introduced into the three-division classifier shown in FIG. 15 at a rate of 31.0 kg / h via the second quantitative feeder 24. As a result, it has a sharp particle size distribution containing 15% by number of particles having a weight average particle diameter of 5.7 μm and a particle diameter of 3.17 μm or less and 1.0% by volume of particles having a particle diameter of 8.0 μm or more. A medium powder was obtained with a classification yield of 82%.

Example 4 100 parts by weight of an unsaturated polyester resin 4.5 parts by weight of a copper phthalocyanine pigment (CIPigment Blue 15) 4.0 parts by weight of a charge control agent (chromium salicylate complex) 4.0 parts by weight Mixer (FM-75
After mixing well with a mold, Mitsui Miike Kakoki Co., Ltd.), the mixture was kneaded with a twin-screw kneader (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.) set at a temperature of 100 ° C. The obtained kneaded material was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely pulverized material as a powder raw material for producing a toner. The obtained toner raw material was finely pulverized and classified by the apparatus system shown in FIG. In the present embodiment, the impingement type air current pulverizer having the configuration shown in FIG. 6 is used, and the multi-divided classifier as the second classifying means includes:
As in the first embodiment, the one shown in FIG. 16 was used. Also, the first
As a classifier, a rotary airflow classifier similar to that shown in FIG. 14 was used. The classifier had a diameter of 200 mm and the number of revolutions of the classifier was 3,500 rpm. Further, as the third classifying means, an air-flow classifier similar to that shown in FIG. 5 as in Example 1 was used, and the rotation speed of the rotor of the classifier was 5500 rpm. p. m. And

In the present embodiment, first, the powdery raw material composed of the coarsely pulverized product is supplied to the table type first constant-quantity feeder 21 to 33.0.
At a rate of kg / h, the mixture was supplied to the rotary airflow classifier 22 having the configuration shown in FIG. 14 through the supply pipe 125 by the injection feeder 35 to classify the first coarse powder and the first fine powder. The first coarse powder classified by the classifier was introduced into the impinging airflow fine pulverizer 28 having the configuration shown in FIG. The coarse powder supplied from the pulverized material supply pipe 41 of the pulverizer 28 has a pressure of 6.0 kg / cm.
² (G), finely pulverized using 6.0 Nm ³ / min compressed air, and then the finely pulverized material is introduced into the airflow classifier 1 having the configuration shown in FIG. Classified into a second coarse powder and a second fine powder. The ultrafine powder as the second fine powder classified by the airflow classifier 1 is collected and removed by the collection cyclone 2. On the other hand, the second coarse powder was again introduced into the airflow classifier 22 and circulated while being mixed with the toner powder raw material supplied in the raw material introduction section, and closed circuit pulverization was performed.
The first fine powder classified by the airflow classifier 22 is supplied to the exhaust fan 1
Cyclone 23 accompanied by suction air from 31
Collected at. The weight average particle size of the first fine powder at this time was 7.0 μm.

The obtained first fine powder is supplied to the vibration feeder 25 and the nozzle 148 through the second quantitative feeder 24.
And 149 at a rate of 35.0 kg / h into a multi-divider 27 having the configuration of FIG. In the classifier 27, the powder is classified into three types of coarse powder, medium powder and fine powder by utilizing the Coanda effect. At the time of introduction into the multi-segmentation classifier 27, the suction force derived from the pressure reduction in the system by the suction pressure reduction of the collection cyclones 29, 30 and 31 communicating with the discharge ports 158, 159 and 160, and the raw material supply nozzle 148
The object to be classified was introduced using compressed air from the injection feeder 32 attached to the device. The introduced first fine powder was immediately classified into three types of coarse powder, medium powder and fine powder in 0.1 seconds or less. Among the classified materials, the coarse powder was collected by the collection cyclone 29, and then introduced into the air-flow type fine pulverizer 28 described above, and then again introduced into the pulverization step.

The classified medium powder has a weight average particle size of 6.
8 μm, and the particle size of 4.0 μm or less is 21% by number of particles.
1.4% by volume of particles having a particle size of 10.08 μm or more
It contained a sharp particle size distribution and had excellent performance as a classified product for toner. At this time, the ratio of the amount of the finally obtained medium powder to the total amount of the charged powder raw materials (that is, the classification yield) was 83%.

Example 5 Fine pulverization and classification were carried out in the same apparatus system using the same toner raw materials as in Example 4. That is, the structure shown in FIG. 6 was used for the impingement type air current pulverizer, and the structure shown in FIG. 16 was used for the multi-divided classifier as the second classification means.
As the first classifying means, a rotary air classifier having the same configuration as that of the first embodiment shown in FIG. 14 was used, but the number of revolutions of the classifying rotor was set at 3900 rpm. Further, as the third classifying means, an air flow classifier similar to that shown in FIG. 5 as in Example 1 was used.
p. m. And In this embodiment, the powder material is
The first fine powder having a weight average particle size of 6.3 μm is obtained by the first and third classification steps and the pulverizing step by supplying the first fine powder to the apparatus system at a rate of 0.0 kg / h. 16 at a rate of 34.0 kg / h through a separator 24, the number of particles having a weight average particle diameter of 6.4 μm and a particle diameter of 4.0 μm or less was reduced to 24% by number.
An intermediate powder having a sharp particle size distribution containing 1.0% by volume of particles having a particle size of 10.08 μm or more was obtained with a classification yield of 80%.

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 set at a temperature of 150 ° C. Kneader (PCM
-30 type, manufactured by Ikegai Iron Works Co., Ltd.). The obtained kneaded material was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely pulverized product for toner production. The toner powder raw material obtained as described above was finely pulverized and classified by an apparatus system shown in FIG. However, the crusher shown in FIG. 18 was used for the impingement type air current crusher, and the crusher shown in FIG.
A classifier that performs centrifugal separation by centrifugal force acting on particles having the following structure was used. In the second classifying step, the multi-segment classifier of FIG. 16 was used.

In the classifier shown in FIG. 15, 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. The inside of the main casing 201 is a classification room 2
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 raised central portion are formed.

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 fed into the guide chamber 205 are separated from each other by the louvers 207. The air is swirled into the classifying chamber 204 from the space. The upper portion 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 a lower portion of the main body casing 201, and classifying air causing a swirling flow from the outside to the classifying chamber 204 is taken in through the classifying louver 209. At the bottom of the classifying chamber 204, a conical (umbrella-shaped) classifying plate 210 whose central portion is high is provided, and a coarse powder discharge port 211 is formed around the outside of the classifying plate 210. A fine powder discharge chute 212 is connected to the center of the classifying plate 210,
12 has an L-shaped lower end, and the bent end is positioned outside the side wall of the lower casing 202. Further, the chute 212 is connected to a suction fan via fine powder collecting means such as a cyclone or a dust collector, and applies a suction force to the classifying chamber 204 by the suction fan to classify the chute from between the classifying louvers 209. The swirling flow required for classification is caused by the suction air flowing into the chamber 204.

In this comparative example, an airflow classifier having the above-described structure was used as the first classifying means. However, the supply chamber 208 contained in the guide chamber 205 a coarsely pulverized material which was a powder material for toner production. When the air is supplied, the air containing the coarsely pulverized material flows from the guide chamber 205 to the classifying chamber 204 while passing between the louvers 207 while being dispersed at a uniform concentration while flowing. The coarsely crushed material that has flowed into the classifying chamber 204 while swirling increases along with the suction air flow that flows from between the classifying louvers 209 at the lower part of the classifying chamber generated by the suction fan connected to the fine powder discharge chute 212, The particles are centrifuged into coarse powder and fine powder by the centrifugal force acting on each particle. Then, the coarse powder swirling around the outer peripheral portion in the classification chamber 204 is discharged from the coarse powder discharge port 211 and the lower hopper 203
The fine powder that is discharged by the fine powder and moves to the center along the upper inclined surface of the classification plate 210 is discharged by the fine powder discharge chute 212.

In this comparative example, the powdery raw material composed of coarsely pulverized material was 13.0 kg /
h at a rate of h, and supply it to the airflow classifier shown in FIG.
The particles were classified by centrifugation by the centrifugal force acting on the particles. The classified coarse powder passes through a coarse powder discharge hopper 203 as shown in FIG.
8 is introduced into the pulverizer from the pulverized material supply port 165 of the impingement type air pulverizer. The coarse powder has a pressure of 6.0 kg / c.
After being pulverized by the pulverizer using compressed air of m ² (G) and 6.0 Nm ³ / min, the pulverized material is again mixed with the toner pulverized raw material supplied at the raw material introduction unit while being pulverized. The circuit was circulated through the air classifier shown in FIG. 15 to perform closed circuit pulverization. On the other hand, the first fine powder classified by the airflow classifier was collected by the cyclone 23 while being accompanied by the suction air from the exhaust fan. At this time, the weight average particle diameter of the fine powder was 7.1 μm.

The obtained fine powder is supplied to the vibrating feeder 25 and the nozzles 148 and 1 through the second quantitative feeder 24.
In order to classify into three types of coarse powder, medium powder and fine powder by utilizing the Coanda effect at a rate of 15.0 kg / h through 49, the mixture was introduced into a multi-segment classifier 27 shown in FIG. At the time of introduction, a suction force derived from the reduced pressure in the system due to the reduced pressure of the collection cyclones 29, 30 and 31 communicating with the outlets 158, 159 and 160 was used. as a result,
A classified product having a particle size distribution containing 27% by number of particles having a weight average particle diameter of 6.9 μm and particles having a particle diameter of 4.0 μm or less and 1.5 vol% containing particles having a particle diameter of 10.08 μm or more was classified. Obtained at 71%. Thus, both the processing efficiency and the classification efficiency were inferior to those of Examples 1 to 3.

[0101]Comparative Example 2 FIG. 4 shows the same toner raw materials as in Examples 1 to 3.
Pulverization and classification were performed in the equipment system. Impact airflow
The conventional crusher shown in FIG.
As in the case of the first to third embodiments, the classifying means includes a circuit having the configuration shown in FIG.
A rotary airflow classifier was used. However, the classification rotor of the classifier
The classification was performed at a rotation speed of 4500 rpm. or,
The second classification means was the same as in Comparative Example 1. As a result, the powder
When body material was supplied at a rate of 10.0 kg / h,
A fine powder having an amount average particle size of 6.3 μm was obtained. Next, the obtained fine
FIG. 1 shows a second classifying means for powder at a rate of 12.0 kg / h.
Introduced into a multi-segment classifier with the configuration shown in Fig. 6 to perform classification.
Was. As a result, the weight average particle diameter was 6.1 μm and the particle diameter was 4.0.
It contains 33% by number of particles having a particle size of μm or less and has a particle size of 10.08 μm.
powder containing 0.5% by volume of particles of m or more
The product was obtained with a classification yield of 67%. Thus, in Examples 1-3
In comparison, both the processing efficiency and the classification yield were inferior.

[0102]Comparative Example 3 A material having the same formulation as in Examples 4 and 5 was prepared using Henschel Miki.
Sir (FM-75, manufactured by Mitsui Miike Kakoki Co., Ltd.)
After mixing, a twin-screw kneader (PC
M-30, manufactured by Ikegai Iron Works Co., Ltd.). Obtained
The kneaded material is cooled and coarse powder is reduced to 1 mm or less with a hammer mill.
To obtain a coarsely pulverized product which is a powder raw material for toner production.
The obtained toner raw material is finely powdered by the apparatus system shown in FIG.
Crushing and classification were performed. However, Fig. 1
Using a crusher with the configuration shown in Fig. 8, the primary classifier is
An airflow classifier having a configuration of 15 was used. Also, the second classification means
Was the same as Comparative Example 1. Table-type first fixed-rate supply
Powder material at a rate of 12.0 kg / h with a machine 21
Via the supply pipe 208 in the injection feeder 35
It supplied to the airflow classifier shown in FIG. 15 and performed classification. Minute
The graded coarse powder passes through the coarse powder discharge hopper 203,
The supply port 165 of the object to be crushed of the impingement type air current crusher shown in FIG.
And pressure 6.0 kg / cm^Two(G), 6.0
Nm^Three/ Min using compressed air at / min.
Mixed with the toner pulverized raw material supplied at the raw material introduction section
While being introduced into the airflow classifier again, circulated and closed
Road crushing was performed. Classification by the airflow classifier shown in FIG.
The classified fine powder is entrained by the suction air from the exhaust fan.
While being collected by the cyclone 23, the second metering machine
24. The weight average particle size of the fine powder at this time is
It was 7.0 μm.

The obtained fine powder is supplied to the vibration feeder 25 and the nozzles 148 and 1 through the second quantitative feeder 24.
In order to classify into three kinds of coarse powder, medium powder and fine powder by utilizing the Coanda effect at a rate of 14.0 kg / h through 49, multi-division classification shown in FIG. Machine 27
Was introduced. Upon introduction, the collection cyclones 29, 30 and 3 communicating with the outlets 158, 159 and 160
The suction force derived from the reduced pressure in the system by the reduced pressure of 1 was used. As a result, 28% by number of particles having a weight average particle diameter of 6.5 μm and a particle diameter of 4.0 μm or less were contained, and a particle diameter of 10.
A medium powder having a particle size distribution containing 1.6% by volume of particles of 08 μm or more was obtained with a classification yield of 66%. Thus, both the processing efficiency and the classification efficiency were inferior to those of Examples 4 and 5.

Table 1: Configuration of toner production methods of Examples and Comparative Examples

[0105]

According to the present invention, in a method for producing a toner, a toner having a small particle size and a sharp particle size distribution can be obtained with a high processing efficiency and a high classification yield. As a result of effectively preventing the toner from fusing, agglomerating, and coarsening, and effectively preventing abrasion of the apparatus due to the toner components, a high-quality toner can be continuously and stably manufactured. Further, according to the present invention, when used for image formation, compared with the conventional method, it is possible to obtain an excellent image having stable image density and high durability, and having no image defects such as fogging and poor cleaning. An electrostatic image developing toner having a small particle size and a sharp particle size distribution can be obtained at low cost. In particular, according to the present invention, it is possible to obtain a toner having a sharp particle size distribution from a toner raw material having a weight average particle size of 10 μm or less, and further obtain a sharp particle size distribution from a toner raw material having a weight average particle size of 8 μm or less. It is possible to efficiently manufacture an electrostatic image developing toner having a cloth .

[Brief description of the drawings]

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

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

FIG. 3 is a schematic diagram showing a specific example of an apparatus system for performing the toner manufacturing method of the present invention.

FIG. 4 is a schematic view showing a specific example of an apparatus system for performing a manufacturing method of a comparative example of the present invention.

FIG. 5 is a schematic sectional view of an airflow classifier used in a third classification step in the present invention.

FIG. 6 is a schematic cross-sectional view of a pulverizing apparatus which is a specific example of an impingement type airflow pulverizing means.

FIG. 7 is a view showing an example of a collision member in the crushing device.

FIG. 8 is an enlarged view of a grinding chamber in FIG.

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

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

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

FIG. 12 is a sectional view taken along line D-D 'in FIG.

FIG. 13 is a schematic cross-sectional view of a pulverizing apparatus as another specific example of the impingement-type airflow fine pulverizing means.

FIG. 14 is a schematic sectional view of an example of a rotary airflow classifier used for the first classifying means.

FIG. 15 is a schematic cross-sectional view of an example of a classifier used for a first classifier of a comparative example.

FIG. 16 is a schematic sectional view of an example of a multi-segment classifier used for a second classifier.

FIG. 17 is a flowchart for explaining a conventional manufacturing method.

FIG. 18 is a schematic sectional view of a conventional collision-type airflow pulverizer.

[Explanation of symbols]

 1: Air flow classifier in the third classification step 2, 23, 29, 30, 31: Collection cyclone 3: First fine pulverization discharge pipe 4: Second coarse powder discharge pipe 5: Second fine powder discharge pipe 6: Super Fine powder 7: Classification chamber 8: Classification rotor 9: Fine powder discharge pipe 10: Classification rotor bearing 11, 12: Secondary air input pipe 13: Coarse powder discharge hopper 14: Body casing 15: Raw material straightening plate 16: Fine pulverized material Input port 17: Guide room 18: Fine powder collecting means 19: Suction fan 20: Frequency converter 21: First quantitative feeder 22: First classifier 24: Second quantitative feeder 25: Vibration feeder 27: Multi-divider classifier 28: Air flow type fine pulverizer 32, 35: Injection feeder 40: High pressure gas injection nozzle 41: Pulverized object supply pipe 42: Pulverized object 43, 162: Acceleration pipe 44: Acceleration pipe throat part 45: High pressure gas injection nozzle slot Ports 46, 101: Pulverized material supply port 47, 102: High pressure gas supply port 48, 103: High pressure gas chamber 49, 92: High pressure gas introduction pipe 50, 163: Acceleration pipe outlet 51, 164: Collision member 52, 52 ', 166: collision surface 53, 168: crushing chamber 54: crushing chamber side wall 55, 167: crushed material discharge port 61: crushing member edge 62: crushing chamber front wall 91: crushing member support 121, 201: main body Casing 122: Classification room 123: Guide room 124: Classification rotor 125: Raw material inlet 126: Air inlet 128: Frequency converter 129: Fine powder discharge pipe 130, 134: Fine powder collection means 131: Suction fan 132: Hopper 133: Rotor Lie valve 135: Dispersion louver 141, 142: Classification chamber side wall 143, 144: Classification chamber lower wall 145: Coandab 146, 147: Classification edge 148, 149: Raw material supply pipe 150: Classification chamber upper wall 151: Inlet edge 152, 153: Inlet pipe 154, 155: Gas introduction adjusting means 156, 157: Static pressure gauge 158, 159, 160: discharge port 161: high-pressure gas supply nozzle 165: powder material supply port 168: pulverizing chamber 201: main casing 202: lower casing 203: hopper 204: classification chamber 205: guide chamber 206: upper cover 207: louver 208: supply Tube 209: Classifying louver 210: Classifying plate 211: Coarse powder discharge port 212: Fine powder discharge chute 213: Upper casing

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-7-92735 (JP, A) JP-A-7-56388 (JP, A) JP-A-8-182936 (JP, A) JP-A-63-1988 101858 (JP, A) Registered utility model 3015458 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/08 B02C 19/06

Claims (2)

(57) [Claims] 1. A mixture containing at least a binder resin and a colorant is melt-kneaded, and after cooling the obtained kneaded product,
A powdered raw material comprising a coarsely pulverized product obtained by pulverizing the cooled product by a pulverizing means is first introduced into a first classification step to classify into a first fine powder and a first coarse powder, and then classified. the first fines and classified product for a toner is produced, and a first coarse powder, which is classified in the first classification step as grinding object, accelerating tube for conveying accelerate grinding object by (i) a high pressure gas and the object to be crushed and a grinding chamber for milling, (ii) in the grinding chamber collision member with collision surface provided opposite to the opening surface of the outlet of the accelerating tube is provided, ( iii) Accelerator tube slot
Formed between the inner wall of the heat sink and the outer wall of the high-pressure gas ejection nozzle
And (iv) the collision surface has a protruding central portion having a protruding center, and a conical shape provided on the outer periphery thereof. (V) further introduced into the crushing chamber into a collision-type airflow crusher having a side wall for further crushing the crushed object by the collision member into the crushing chamber; The finely pulverized material is introduced into a third classifying step using a classifier for classifying the powder using centrifugal force generated by forced vortex, and the second coarse powder and the second fine powder are pulverized. And then recirculating the mixed second coarse powder into the powder raw material, re-introducing it into the first classification step, and subjecting it to a circulation process. 2. A flow straightening plate and a finely pulverized material inlet are provided in a flow path between a collision type air flow pulverizer and a classification chamber of a classifier used in a third classification step, and a dispersed particle flow is provided. 2. The method for producing a toner according to claim 1, wherein the toner is introduced into a classifying chamber of the classifier.