JPH07181736A - Production of electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To obtain a production method of a toner with good pulverization efficiency and to obtain a production method of a toner excellent in fluidity. CONSTITUTION:In the production method of a electrostatic charge developing toner, a collision type gas flow pulverizing means is a finely pulverizing machine having an accelerating tube to carry and accelerate the material to be pulverized with a high pressure gas and a pulverizing room to finely pulverize the material. The material to be pulverized is supplied and accelerated in the accelerating tube and injected from the exit of the accelerating tube to the pulverizing room. The material is subjected to primary pulverization with a projected part of a colliding member having a colliding surface disposed to facing the aperture of the exit of the accelerating tube. The primarily pulverized material is secondarily pulverized with the outer colliding surface around the projected part. The secondarily pulverized material is further subjected to tertiary pulverization with side walls of the pulverizing room. Then, the pulverized material is circulated in a first gas flow classifying means. The fine powder classified by the first gas flow classifying means is give a rather low impact in short time by a collision gas flow pulverizing means addition to the fine pulverizing process. Then the grain size of the particles are controlled by a second classifying means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to electrophotography, electrostatic recording,
The present invention relates to a method for producing a toner for developing an electrostatic charge image in electrostatic printing or the like.

[0002]

2. Description of the Related Art In image forming methods such as electrophotography, electrostatic photography and electrostatic printing, toner is used to develop an electrostatic charge image. 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 more severe, and the particle size of toner has become smaller, and there are no coarse particles and fine particles. There is a growing demand for toners having a sharp particle size distribution with a small number of particles.

As a general method for producing a toner for developing an electrostatic image, a binder resin for fixing the toner on a transfer material, various colorants for producing a tint as a toner, and a charge for imparting an electric charge to particles are used. In the so-called one-component developing method as disclosed in JP-A-54-42141 and JP-A-55-18656, charge control agents and various magnetic materials for imparting transportability to the toner itself. In addition to this, if necessary, dry-mix the release agent and fluidity-imparting agent, and then melt-knead with a general-purpose kneading device such as a roll mill or an extruder, cool and solidify, and then jet-jet crusher or machine. Fine particles are pulverized by various crushing devices such as an impact pulverizer, and classified by various air classifiers so that the particle diameters required for the toner are made uniform. If necessary, a fluidizing agent, a lubricant and the like are dry mixed to obtain a toner. When used in a two-component developing method, after mixing various magnetic carriers and toner,
Used for image formation.

As described above, in order to obtain toner particles which are fine particles, the method shown in the flow chart of FIG. 13 has been generally adopted conventionally. The toner coarsely pulverized material, which is a pulverization raw material, is continuously or sequentially supplied to the first classification means for classification, and the classified coarse powder containing a coarse particle group of a prescribed particle size or more as a main component is sent to the pulverization means for pulverization. Then, it is circulated again to the first classifying means.

The finely pulverized toner product containing other particles within the specified particle size range and particles having the specified particle size or less as the main component is sent to the second classifying means, and the intermediate powder containing the particle group having the specified particle size as the main component. It is classified into a body and a fine powder whose main component is a particle group having a particle size not larger than a prescribed size. As the pulverizing means, various pulverizing devices are used, but for pulverizing the toner coarsely pulverized product mainly containing the binder resin,
A jet stream type pulverizer using a jet stream as shown in FIG. 14, particularly a collision type air stream pulverizer is used.

A collision type air flow pulverizer using a high pressure gas such as a jet air stream conveys a pulverized raw material by a jet air stream and jets it from an outlet of an accelerating pipe to face the opening surface of the outlet of the accelerating pipe. The crushing raw material is crushed by the collision force of the collision member provided and crushed by the impact force. For example, in FIG.
In the collision type air flow crusher shown in FIG.
The collision member 4 is provided so as to face the outlet 13 of the accelerating pipe 3 connected to the accelerating pipe 3, and the high-pressure gas supplied to the accelerating pipe 3 causes the crushing raw material supply port 1 communicated with the accelerating pipe 3 to enter the accelerating pipe 3. The pulverized raw material 7 is sucked, and the pulverized raw material 7 is ejected together with the high-pressure gas to collide with the collision surface 16 of the collision member 4, and the impact is pulverized.

Conventionally, as shown in FIGS. 14 and 15, the collision surface 16 of the collision member in such a crusher is perpendicular or inclined (eg, to the direction of the jet stream of the crushed raw material (axial direction of the accelerating tube)). A flat surface having an angle of 45 ° has been used (see JP-A-57-50554 and JP-A-58-143853). In the crusher shown in FIG. 14, the pulverized raw material 7 having a coarse particle size is supplied to the accelerating pipe 3 through the supply port 1 and is jetted from the jet nozzle 2 so that the pulverized raw material is crushed by the collision surface 1 of the collision member 4.
6 and crushed by the impact force, discharge port 5
Is discharged to the outside of the crushing chamber 8. However, collision surface 1
When 6 is perpendicular to the axial direction of the accelerating tube 3, the jet nozzle 2
The ratio of the raw material powder blown out from the powder and the powder reflected by the collision surface 16 coexisting in the vicinity of the collision surface 16 is high. Therefore, the powder concentration near the collision surface 16 is high and the pulverization efficiency is high. Not good.

Further, the primary collision on the collision surface 16 is the main component, and it cannot be said that the secondary collision with the crushing chamber wall 6 is effectively utilized. Further, in a crusher having a collision surface whose angle is perpendicular to the accelerating tube 3, fusion and agglomerates are likely to occur due to local heat generation at the time of crushing the thermoplastic resin, which makes stable operation of the device difficult. And cause a decrease in crushing ability.
Therefore, it was difficult to increase the powder concentration for use. In the crusher shown in FIG. 15, the collision surface 16 is the acceleration tube 3
Since the powder concentration in the vicinity of the collision surface 16 is lower than that of the crusher shown in FIG. 14, since it is tilted with respect to the axial direction of, the crushing pressure is dispersed and decreases. Further, it cannot be said that the secondary collision with the crushing chamber wall 6 is effectively utilized.

As shown in FIG. 15, when the collision surface 16 is inclined at an angle of 45 ° with respect to the accelerating tube 3, the above problems are less likely to occur when the thermoplastic resin is crushed. However, the impact force used for crushing when colliding is small,
Further, since the crushing due to the secondary collision with the crushing chamber wall 6 is small, the crushing ability is 1/2 to 1/1.
The crushing ability drops to 5. Japanese Patent Laid-Open No. 1-148740 and Japanese Patent Laid-Open No. 1-254266 have been proposed as collision-type airflow crushers in which the above problems have been solved. In Japanese Utility Model Laid-Open No. 1-148740, as shown in FIG. 17, the raw material collision surface 16 of the collision member 4 is arranged at right angles to the axis of the accelerating tube 3, and the conical projection 14 is formed on the raw material collision surface. It has been proposed to prevent the reflected flow on the collision surface by providing it.

Further, in Japanese Unexamined Patent Publication No. 1-254266,
As shown in FIG. 16, by making the tip portion of the collision surface 16 of the collision member 4 into a specific conical shape, the powder concentration in the vicinity of the collision surface is lowered, and the secondary collision with the crushing chamber wall 6 is efficiently performed. A collision-type airflow crusher has been proposed. With the above-mentioned constitution, the conventional problems are considerably improved, but it is not sufficient yet, and as a recent need, a finer pulverized product is desired, and further fine pulverization with good pulverization efficiency is desired. The machine is long-awaited.

For example, when a toner having a weight average particle diameter of 8 μm and a volume% of particles of 4 μm or less is 1% or less, a collision type equipped with a classification mechanism for removing a coarse powder region is used. The raw material is pulverized to a predetermined average particle size by a pulverizing means such as an air flow pulverizer, and the coarse powder is removed, and then the pulverized product is subjected to another classifier to remove the fine powder to remove the desired intermediate powder. Is getting

The weight average particle size referred to here is data measured by a Coulter counter TA-II type manufactured by Coulter Electronics Co. (USA) using a 100 μm aperture. It is also known that when toner raw materials are crushed by a collision type airflow crusher using the above jet airflow, the toner has projections that are sharply angled on the surface when viewed microscopically.

These protrusions sometimes impede the fluidity of the toner. If the fluidity is poor, the bridge in the toner hopper of a copying machine, a facsimile machine, a laser beam printer or the like, the non-uniform charging property of the toner surface, or the like. Is a copier,
It is known that a phenomenon such as a decrease in image density occurs when a facsimile, a laser beam printer or the like is used for a long time, and one cause of such a phenomenon is poor fluidity of toner. There is. As means for solving this problem, JP-A-61-61627 and JP-A-63
As proposed in Japanese Patent Publication No. 249155, there is known a method of spheroidizing a toner while pulverizing the toner.

However, these methods are methods of crushing by a collision between a rotor rotating at a high speed and a liner, but in this method, the limit particle size of crushing is larger than that of a collision type airflow crusher using a jet stream. Therefore, when a fine pulverized particle size is desired, the efficiency is remarkably reduced. In particular, when trying to obtain a toner fine powder having a weight average particle diameter of 9 μm or less, the efficiency is remarkably reduced. Therefore, a method for producing a toner for developing an electrostatic charge image, which has good pulverization efficiency and excellent quality, has been desired.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner manufacturing method which overcomes the above-mentioned problems in the toner manufacturing method. That is, an object of the present invention is to provide a method for producing a toner having good pulverization efficiency and a method for producing a toner having excellent fluidity.

[0016]

The above object can be achieved by the present invention described below. That is, in the present invention, a mixture containing at least a binder resin and a colorant is melt-kneaded, the kneaded product is cooled, the cooled product is pulverized by a pulverizing means to obtain a pulverized product, and the obtained pulverized product is classified by air flow. The powder is classified into coarse powder and fine powder by means, and the classified coarse powder is finely pulverized by the collision type air flow pulverization means to produce fine powder, and the fine powder is classified by the air flow classification means from the produced fine powder and classified. In the method for producing a toner for developing an electrostatic charge image from fine powder, the collision type airflow pulverizing means comprises an accelerating tube for accelerating and conveying the pulverized object by high pressure gas, and a pulverization for finely pulverizing the pulverized object. A fine pulverizer having a chamber and a colliding surface provided in the accelerating tube for discharging the accelerated object to be crushed into the crushing chamber from an outlet of the accelerating tube and facing the opening surface of the outlet of the accelerating tube. Primary crushed by the protruding portion of the collision member having a primary crushed primary The crushed material is secondly crushed on the outer peripheral collision surface provided on the outer circumference of the projecting portion, and the secondary crushed secondary crushed material is further crushed on the side wall in the crushing chamber, and then circulated to the first air stream classification means. Separately from the fine pulverizing step, the fine powder classified by the first air stream classifying means is subjected to a relatively lower impact than the collision type air stream grinding means for a short time, and then the particle size is adjusted by the second classifying means. And a method for producing an electrostatic charge image developing toner.

[0017]

In the method for producing a toner for developing an electrostatic charge image, the collision type air flow crushing means is provided with an accelerating tube for accelerating and conveying the crushed object by the high pressure gas, and a crushing chamber for finely crushing the crushed object. As a fine pulverizer having a crushing object, an object to be crushed is supplied into the accelerating pipe, the accelerated object to be crushed is discharged into the crushing chamber from an outlet of the accelerating pipe, and a collision surface provided opposite to the opening surface of the outlet of the accelerating pipe. Primary crushed by the projecting portion of the collision member having the, secondary crushed primary crushed primary crushed product on the outer peripheral collision surface provided on the outer periphery of the projecting portion, further crushed secondary crushed secondary crushed product After performing tertiary pulverization on the side wall of the room, it is circulated to the first air stream classification means, and into fine powder classified by the first air stream classification means,
Separately from this fine pulverization step, a relatively low impact is applied for a short time from the collision type air flow pulverizing means, and then the particle size is adjusted by the second classifying means to provide a toner having excellent pulverization efficiency and fluidity. You can

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described more concretely with reference to the accompanying drawings showing preferred embodiments. FIG. 1 is an example of a flowchart showing an outline of the manufacturing method of the present invention. In the present invention, the pulverized raw material is supplied to the first classifying means and classified into coarse powder and fine powder in the first classifying means. Coarse powder is introduced and crushed by collision type air flow crushing means,
After pulverization, it is circulated and introduced into the first classification means. Fine powder
After being treated by the low impact means, it is classified by the second classifying means, and is classified into a medium powder having a particle size within at least the specified particle size and a fine powder having a particle size not more than the specified particle size.
The classified intermediate powder is used as a toner as it is, or after being mixed with an additive such as hydrophobic colloidal silica, it is used as a toner. It is desirable that the classified fine powder is supplied to the melt-kneading step for producing the pulverized raw material and reused.

As an example of the collision type air flow crushing means used in the present invention, a collision type air flow crusher of the type shown in FIG. 2 is exemplified. In FIG. 2, the crushed raw material 7 to be crushed is
It is supplied to the accelerating pipe 3 from a crushing raw material supply port 1 provided in the crusher wall 11 above the accelerating pipe 3. Compressed gas such as compressed air is introduced into the accelerating tube 3 from the compressed gas supply nozzle 2, and the pulverized raw material 7 supplied to the accelerating tube 3 is instantaneously accelerated to have a high speed. Acceleration tube exit 1 at high speed
The crushing raw material 7 discharged from the crushing chamber 3 into the crushing chamber 8 is
It collides with the collision surface of and is crushed.

In the crusher shown in FIG. 2, a cone-shaped protruding central portion 14 is formed on the collision surface of the collision member, and primary crushing of the object to be crushed around the protruding central portion is carried out at the protruding central portion. It has an outer peripheral collision surface 15 for further crushing an object by collision. Further, the crushing chamber 8 has a side wall 6 for crushing the secondary crushed material secondarily crushed by the outer circumferential collision surface 15 by collision.
have.

FIG. 3 is a cross sectional plan view of FIG. 2 and will be described in more detail. As described above, by providing the cone-shaped projection 14 having the central portion protruding on the raw material collision surface, the solid-gas mixture flow of the pulverized raw material and the compressed air ejected from the acceleration tube 3 is formed by the projection 1.
The surface of No. 4 is subjected to primary crushing, and the peripheral collision surface 15 is subjected to secondary crushing, and then the crushing chamber side wall 6 is subjected to tertiary crushing. This time,
The apex angle α (°) of the protruding central portion 14 projecting on the collision surface of the collision member 4 and the inclination angle β (°) of the outer peripheral collision surface 15 with respect to the vertical plane of the central axis of the acceleration tube are 0 <α <90, β. When> 0 30 ≦ α + 2β ≦ 90 is satisfied, grinding is performed very efficiently.

When α ≧ 90, it is not preferable because the reflected flow of the pulverized material that is primarily pulverized on the surface of the central portion 14 of the protrusion disturbs the flow of the solid-gas mixture flow ejected from the acceleration tube 3. β =
When 0, that is, when the outer peripheral collision surface is at a right angle to the solid-gas mixture flow, as shown in FIG. 17, the reflected flow at the outer peripheral collision surface 15 flows toward the solid-gas mixture flow, and This is not preferable because it causes turbulence in the gas mixture flow. Further, when β = 0, the powder concentration on the outer peripheral collision surface 15 becomes large, and when the powder of the thermoplastic resin or the powder containing the thermoplastic resin as the main component is used as the raw material, Fusing and agglomerates are likely to occur.
When such a fused substance is generated, stable operation of the device becomes difficult.

Further, when α and β are α + 2β <30, the impact force of the primary crushing on the surface of the projections is weakened, and the crushing efficiency is lowered, which is not preferable. Also, α and β are α
When + 2β> 90, the reflected flow on the outer peripheral collision surface flows to the downstream side of the solid-gas mixture flow, so that the impact force of the tertiary pulverization on the side wall of the pulverization chamber is weakened and the pulverization efficiency is reduced. As described above, when α and β satisfy 0 <α <90, β> 0 30 ≦ α + 2β ≦ 90, and more preferably 10 <α <805 5 <β <40, as shown in FIG. The secondary and tertiary pulverization is efficiently performed, and the pulverization efficiency can be improved.

It is a feature of the present invention that the number of collisions is increased as compared with the conventional crusher and the collisions are more effective.
It is possible to improve the pulverization efficiency, prevent the generation of a fused substance during pulverization, and perform stable operation. The structure of the crusher used in the present invention is not limited to the structure shown in FIG. FIG. 4 is a schematic sectional view of another preferable crusher used in the present invention, FIG. 5 is an enlarged sectional view taken along the line AA ′ of FIG. 4, and FIG.
It is sectional drawing in a B'line.

Explaining the crusher of FIG. 4, an accelerating tube 21 for conveying and accelerating an object to be crushed by a high-pressure gas, and a collision member 3 having a collision surface provided facing the exit of the accelerating tube.
0, the accelerating pipe 21 has a Laval nozzle shape, a high-pressure gas jet nozzle 23 is arranged upstream of the throat part of the accelerating pipe 21, and the outer wall of the high-pressure gas jet nozzle 23 and the throat part 2 are arranged.
The crushed material supply port 24 is provided between the two inner walls, and the acceleration tube 2
The crushing chamber connected to the outlet of No. 1 has a circular cross section in the axial direction.

The crushed material supplied from the crushed material supply cylinder 25 is centered on the inner wall of the accelerating tube throat portion 22 of the accelerating tube 21 having a Laval nozzle shape with its central axis arranged in the vertical direction. It reaches the object to be crushed supply port 24 which is formed between the shaft and the outer wall of the high pressure gas ejection nozzle 23 which is coaxial. On the other hand, the high-pressure gas is introduced from the high-pressure gas supply port 26, passes through the high-pressure gas chamber 27, and passes through one or more high-pressure gas introduction pipes 28, and rapidly from the high-pressure gas ejection nozzle 23 toward the acceleration pipe outlet 29. Gush while expanding to.

At this time, due to the ejector effect generated in the vicinity of the accelerating tube throat portion 22, the crushed material is entrained in the gas coexisting with the crushed material and directed from the crushed material supply port 24 toward the acceleration tube outlet 29. Is rapidly sucked and rapidly accelerated while being uniformly mixed with the high-pressure air flow in the accelerating tube throat portion 22, and the collision surface of the collision member 30 facing the accelerating tube outlet 29 is provided with a uniform solid mixed air flow with no uneven dust concentration. Collide in the state. Since the impact force generated at the time of collision is given to the sufficiently dispersed individual particles (objects to be crushed), crushing can be performed very efficiently. The crushed material crushed on the collision surface of the collision member 30 is repeatedly collided between the side wall 32 of the crushing chamber and the surface of the collision member 30 to improve the pulverization efficiency, and is disposed behind the collision member 30. It is discharged from the crushed material discharge port 33.

On the collision surface of the collision member 30, the projecting central portion 14 and the outer periphery for further crushing the primary crushed material crushed at the projecting central portion around the projecting central portion by further collision. It has a collision surface 15. Further, the crushing chamber 34 has a side wall 32 for thirdly crushing the secondary crushed material crushed secondarily on the outer peripheral collision surface by collision. Similar to the crusher of FIG. 2, the object to be crushed is first crushed on the surface of the protrusion on the collision surface, further crushed secondly on the outer peripheral collision surface 15, and then thirdly crushed on the side wall 32 of the crushing chamber.

In the crusher shown in FIG. 4, the central axis of the accelerating tube is arranged in the vertical direction, and the crushed material is supplied from the inner wall of the accelerating tube and the outer wall tube of the high-pressure gas jet nozzle, and the jetting direction of the high-pressure gas and the crushed article. By making the supply directions of the same in the same direction, it is possible to disperse the pulverized material in the high-pressure air stream that is uniformly ejected so that there is no bias due to the dust concentration. Examples of other crushers used in the present invention are shown in FIGS. 7 and 8. 8 is a sectional view taken along the line CC 'in FIG.

Explaining the crusher of FIG. 7, it is provided with an accelerating tube 21 for accelerating the crushing raw material by high-pressure gas, and a collision surface for crushing the powder ejected from the accelerating tube 21 by a collision force. A collision type air flow crusher having a crushing chamber 34 and the collision member 30 provided facing the accelerating tube outlet, the throat portion 36 and the accelerating tube outlet 37 of the Laval-shaped accelerating tube 21. Is provided with a crushing raw material supply port 24 in the entire circumferential direction of the acceleration tube, and the crushing chamber has a substantially circular cross-sectional shape, and the collision member 3
It is a collision type airflow crusher having a crushed material discharge port 33 at the rear.

Further, the central axis of the accelerating tube 21 has a vertical direction, and the collision surface of the collision member 30 is crushed at the protruding central portion 14 and the protruding central portion around the protruding central portion. It further has an outer peripheral collision surface 15 for further crushing the primary crushed material to be crushed by collision. Further, the crushing chamber 34 has a side wall 32 for thirdly crushing the secondary crushed material crushed secondarily on the outer peripheral collision surface by collision. Explaining the action of the high-pressure gas, the high-pressure gas first enters from the high-pressure gas supply ports 27 on the left and right of the high-pressure gas chamber 27, and the arteries are made uniform due to pressure fluctuations and the like, and then the central portion of the pulverized material supply cylinder 25. A Laval nozzle 35 provided in the accelerating pipe 21 flows into the accelerating pipe 21.

Like the Laval nozzle 35, the accelerating tube 21 also has a Laval shape with a divergent end, and the high-pressure gas flowing into the accelerating tube 21 is accelerated to the supersonic region while expanding.
In the process, the high pressure gas is decompressed, and the pressure of the gas at the exit of the acceleration tube 21 becomes substantially the same as the pressure in the crushing chamber 34. On the other hand, in the circular crushing chamber 34, the crushing chamber 34
When the gas inside is sucked, a suction flow is generated inside the crushing chamber. Then, due to the action of this suction flow, the surface of the collision member 30 is in a reduced pressure state. The shape of the crushing chamber is not limited to this.

Due to the depressurizing action of the surface of the collision member 30, the jet flow emitted from the acceleration tube 21 is further accelerated and collides with the surface of the collision member 30. At this time, the object to be crushed is first crushed on the surface of the projection 14 on the collision surface of the collision member 30, further pulverized secondly on the outer peripheral collision surface 15, and then pulverized tertiaryly on the crushing chamber side wall 32. Next, the action of the pulverized raw material supplied will be described. The pulverized raw material, which is the pulverized material, is supplied from the pulverized material supply cylinder 25. The supplied pulverized raw material is sucked and discharged into the accelerating pipe 21 from the pulverized raw material supply port 24 in the lower portion of the supply cylinder. The principle of sucking and discharging the raw material is based on the ejector effect by the expansion and decompression in the accelerating tube of the high pressure gas described above. At this time, since the crushing raw material supply port 24 is provided in the entire circumferential direction of the accelerating tube between the throat portion of the Laval-shaped accelerating tube and the accelerating tube outlet, it is sufficiently dispersed and accelerated by the high-speed air flow.

It is preferable that the pulverized material supply port 24 is provided in the entire circumferential direction or in plural (n ≧ 2). If there is only one crushing material supply port, the dispersion state of the material in the accelerating tube will be biased, which will reduce the crushing efficiency and is not preferable. The pulverized raw material thus dispersed and sucked into the accelerating pipe 21 is completely dispersed by the high-speed airflow emitted from the Laval nozzle 35 provided in the central portion of the pulverized material supply cylinder 25.

Next, the dispersed pulverized raw material is accelerating tube 21.
It is accelerated by the high-speed airflow flowing inside, and becomes a supersonic solid-gas mixture flow. This solid-gas mixture flow becomes a solid-gas mixture jet flow after exiting the accelerating pipe 21, and collides with the collision member 30 by the same action as the aforementioned jet flow. In the crusher of FIG. 7, the central axis of the accelerating tube is arranged in the vertical direction and has a specific raw material supply method, and the raw material powder that is the object to be pulverized is more strongly dispersed to improve the pulverization efficiency. It is possible to obtain excellent pulverization processing capacity. In addition, due to the uniform dispersion of the dust concentration due to the strong dispersion of the crushed material, the local fusion and wear of the crushed material in the collision member, the acceleration tube and the crushing chamber are significantly larger than those of the conventional collision type air flow crusher. It can be reduced and stable operation can be achieved.

The grinders shown in FIGS. 4 and 7 are different from the grinder having the structure shown in FIG.
Since the pulverized raw material in the acceleration tube can be dispersed more uniformly, the pulverization efficiency can be further improved. still,
Also in the pulverizers of FIGS. 4 and 7, when α and β satisfy 0 <α <90, β> 0 30 ≦ α + 2β ≦ 90, and more preferably 10 <α <805 5 <β <40, The secondary and tertiary pulverization is efficiently performed, and the pulverization efficiency can be improved.

In the above crusher, the inner diameter of the acceleration tube outlet is preferably smaller than the diameter b of the collision member. It is preferable that the tip of the protruding central portion protruding from the collision surface of the collision member and the central axis of the acceleration tube substantially coincide with each other from the viewpoint of uniform pulverization. The distance a between the exit of the acceleration tube and the end of the collision surface of the collision member is preferably 0.1 times to 2.5 times or less the diameter of the collision member, and more preferably 0.2 times to 1.0 times. If it is less than 0.1 times, the dust concentration in the vicinity of the collision surface will be high, while if it is more than 2.5 times, the impact force will be weakened and the pulverization efficiency will tend to be reduced.

The shortest distance c between the end of the collision surface of the collision member and the side wall (inner wall) of the crushing chamber is 0.
It is preferably 1 to 2 times or less. If it is less than 0.1 times, the pressure loss during passage of high-pressure gas is large, and not only the pulverization efficiency tends to decrease, but also the flow of the pulverized material tends to not go smoothly. The effect of the third collision of the object to be crushed is reduced, and the crushing efficiency is lowered. The shape of the crushing chamber is not particularly limited as long as the distance between the end of the collision surface of the collision member and the side wall of the crushing chamber satisfies the above numerical value.

More specifically, the length of the accelerating tube is 50 to 5
00 mm is preferable, and the diameter of the collision member is 30 to 300 m
It is preferred to have m. Further, it is preferable in terms of durability that the collision surface of the collision member and the side wall of the crushing chamber are made of ceramic. By crushing by such a collision type air flow crushing means, the crushing ability and the crushing efficiency of the crusher are remarkably improved. In particular, this effect becomes more remarkable as the desired particle size is smaller. This is particularly effective when producing a toner fine powder having a weight average particle diameter of 9 μm or less.

A known airflow classifier is used as the first classifying means used in the present invention. Examples thereof include DS classifier manufactured by Nippon Pneumatic Mfg. Co., Ltd., Micron Separator manufactured by Hosokawa Micron Co., Ltd., Turbo Classifier made by Nisshin Engineering Co., Ltd. and Dona Selec manufactured by Donaldson Japan. Further, as the low impact means, there can be exemplified a method of giving an impact between a rotating rotor, a blade or a hammer and a liner facing the rotating rotor, or an impact between a large number of rotating pins.

FIG. 9 is a schematic sectional view of a low-impact treatment device using a combination of a rotor and a liner. In the figure, 43 is a rotary shaft, 44 is a casing, 45 is a liner, 46 is a blower blade, 47 is a rotor (with a blade), 48 is an outlet, 49 is a product outlet, 38 is a return passage, 39 is a raw material supply port, 40 Is an inlet, 41 is a jacket, and 42 is a return closing valve. The peripheral speed of the tip of the rotating rotor is 5
0 to 200 m / sec, preferably 70 to 150 m / s
ec, and the processing temperature is the glass transition point of the processing raw material-
Treatment in the temperature range of 5 ° C to -30 ° C of glass transition is desirable. If the treatment temperature is too high, the material to be pulverized will melt in the device, and if it is too low, the pulverization treatment will be insufficient, which is not preferable. In order to control in such a temperature range, cooling or heating is performed as a jacket structure. Alternatively, the temperature may be controlled by introducing cold air or hot air together with the raw material to be treated.

FIG. 10 is a diagram showing the positional relationship between the liner 45 and the rotating rotor 47 of the low impact treatment device shown in FIG. The distance between the liner 45 and the rotor 47 means the difference between the radii of the two circles of the circumference obtained by connecting the tips of the protrusions to the inner circumference of the liner and the locus of the protrusions of the rotor.
The same applies to blades and hammers instead of this rotor.

The distance between the rotor, blade or hammer and the liner is about 0.5 to 10 mm, preferably 0.
Good results have been obtained with a thickness of about 5 to 3 mm. Figure 1
FIG. 1 is a schematic sectional view of another type of low impact treatment device.
The apparatus comprises a cylindrical casing 51 and this casing 5
1 and a rotor 52 arranged coaxially with the casing shaft. The rotor 52 is provided with a plurality of blades 53. Liner 54 and rotor blade 53
A space of a suitable width (a gap of 0.5 to 10 mm, preferably 0.5 to 3 mm) is present between and to form the processing region 55. On the upstream side of the casing 51, a toner processing product 56 and a supply port 58 for the inflow air 57 are provided. A swirl chamber 59 is provided below the supply port 58. The rotor blade 53 in the vicinity of the swirl chamber 59 has a distributor 60 for evenly distributing the input processing material 56 and / or the inflowing air 57 in the processing area 55.
Are provided as appropriate.

A discharge port 61 is provided on the downstream side of the casing 51, and is connected to, for example, a cyclone collector or a bag filter outside the system. In the apparatus of FIG. 11 described above, it is preferable that the peripheral speed and the processing temperature of the rotor blade 53 that rotates at a high speed be within the same range as the apparatus of FIG.
In the low-impact treatment in the apparatus shown in FIGS. 9 and 11, the treatment may be carried out transiently, or may be carried out by recycling so that the residence time can be controlled. This may be set appropriately depending on the physical properties of the processing raw material and the degree of processing, but considering productivity, it is preferable to set the conditions so that the processing can be performed as transiently as possible. As such a device, "Kryptron" manufactured by Kawasaki Heavy Industries, Ltd., "Turbo Mill" manufactured by Turbo Kogyo Co., Ltd., or the like can be adopted.

Since the purpose of the low-impact treatment in the present invention is not to make the toner particles spherical but to modify the surface characteristics, the residence time in the apparatus is extremely short, and the time is the nature of the respective toner treatment raw materials and the rotor. Depending on the peripheral speed of
For example, the peripheral speed is 200 m / sec, the time is 0.01 seconds to 2 seconds, and the time is selected from about 0.01 to 3 minutes depending on the conditions. Therefore, there is little influence on the shape and the surface of the toner, and the ratio of the minor axis to the major axis of the toner at the time of pulverization of 0.60 to 0.70 changes to about 0.65 to 0.85 after the treatment. is there. When the state of the toner surface after the treatment is observed with a scanning electron microscope, no large change in the shape can be seen as compared with that before the treatment, but it is recognized that the angular protrusions are reduced.

If the low impact treatment time (residence time) is made longer than the above-mentioned time, spheroidization of the toner is promoted,
Phenomena such as an increase in toner consumption and an increase in fog due to a decrease in cleaning property become stronger, and on the contrary, if it is too short, the effect of modifying the surface characteristics becomes weak and the fluidity of the toner tends to deteriorate. . The above-mentioned known airflow classifier is used as the second classifying means used in the present invention. Particularly preferably used is, for example, the multi-division classifier shown in FIG. 12 (cross-sectional view) as one of the specific examples.

In FIG. 12, the side walls are 122 and 124.
The lower wall has a shape shown by 125, and the lower wall 123 and the lower wall 125 are provided with knife edge type classification edges 117 and 118, respectively. , The classification zone is divided into three. A raw material supply nozzle 116 that opens into the classification chamber is provided in the lower portion of the side wall 122, and a Coanda block 126 that is bent downward in the direction of the extension of the bottom tangent of the nozzle to form an elliptical arc is provided. Upper wall 127 of classification room
Is a knife edge type air intake edge 11 toward the bottom of the classification chamber.
9, and air inlet pipes 114 and 115 that open to the classification chamber are provided above the classification chamber. Air inlet tubes 114 and 1
15 is a first gas introduction adjusting means 120 such as a damper,
Second gas introduction adjusting means 121 and static pressure gauges 128 and 12
9 is provided. The positions of the classification edges 117 and 118 and the inflow edge 119 differ depending on the type of fine powder and the desired particle size. The bottoms of the classification chambers are provided with discharge ports 111, 112 and 1 which are open to the inside of the chamber in correspondence with respective fractionation areas.
13 is provided. The discharge ports 111, 112 and 113 may be provided with opening / closing means such as valve means, respectively.

The fine powder supply nozzle 116 is composed of a right-angled cylinder portion and a pyramidal cylinder portion, and if the ratio of the inner diameter of the right-angled cylinder portion to the inner diameter of the narrowest part of the pyramid cylinder portion is set to 20: 1 to 1: 1, A good introduction rate is obtained. The classification operation in the multi-division classification area configured as described above is performed as follows, for example.
By decompressing the inside of the classification area through at least one of the discharge ports 111, 112 and 113, and by the airflow flowing in the raw material supply nozzle 116 opening in the classification area by the decompression,
Fine powder is supplied to the classification area through the fine powder supply nozzle 116 at a flow rate of 50 to 300 m / sec.

When the 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 agglomeration of the fine powder, and the classification yield and classification accuracy are likely to deteriorate.
When the fine powder is supplied to the classification area at a flow rate of more than 300 m / sec, the particles tend to be crushed due to collision of the particles with each other, and fine particles are likely to be generated, so that the classification yield tends to be lowered.

The supplied fine powder moves along the curved line 130 by the action of the Coanda block 126 due to the Coanda effect and the action of gas such as air flowing in at that time,
It is classified according to the size of each particle and the size of the weight.
Assuming that the specific gravity of the particles is the same, the larger particles (coarse powder) are outside the airflow (that is, the first particles on the left side of the classification edge 118).
Classification powder), medium powder (particles with a particle size within the specified range) is classified into a second fractionation area between classification edges 118 and 117, and fine powder (particles with a specified particle size or smaller) is classified. Edge 117
Is classified in the third fraction area on the right side of the. The classified coarse powder is discharged through the discharge port 111, the medium powder is discharged through the discharge port 112, and the fine powder is discharged through the discharge port 113.

Regarding the introduction of fine powder into the classification area, a method of suction introduction using the suction force of a cyclone; an air transfer means such as injection is provided in the fine powder supply nozzle,
There is a method of introducing by a suction force from a cyclone and a force of compressed air from an injection; The introduction method using an air transfer means such as suction introduction or injection has a better sealing property of the device system.
It is preferable because it is not required to be introduced by pressure.

The multi-division classifier which is the second classifier is as follows:
There is a Coanda block such as Elbow Jet manufactured by Nittetsu Mining Co., Ltd., and a classification means utilizing the Coanda effect can be mentioned. The size of the classification area of a multi-division classifier is usually [1
Since it is 0 to 50 cm] × [10 to 50 cm], the fine powder can be classified into three or more kinds of particle groups in an instant of 0.1 to 0.01 seconds or less. When the multi-division classifier divides into 3 fractions, the multi-division classifier divides the fine powder into coarse powder (particles with a particle size not less than the specified size), medium powder (particles with a particle size within the specification) and fine powder ( The particles are divided into particles of a specified particle size or less).

Thereafter, the coarse powder passes through the discharge conduit 111 and is collected via a collecting cyclone (not shown).
In order to improve production efficiency, it is preferable to return the collected coarse powder to the pulverizing step and to pulverize again. Medium powder is exhaust pipe 1
It is discharged to the outside of the system via 12 and collected by a collection cyclone to be recovered as a toner product as much as possible. The fine powder is discharged to the outside of the system through the discharge conduit 113, collected by the collection cyclone, and then collected as fine powder having a non-regulated particle size. The collection cyclone also functions as suction decompression means for sucking and introducing fine powder into the classification area through the nozzle 116. It is desirable that the recovered fine powder be supplied to a melt-kneading step for producing a pulverized raw material and reused.

In the present invention, the crushing step shown in the flow chart of FIG. 1 is not limited to this, and for example, one crushing means and two first classifying means or one crushing means and first classifying means. There may be two or more means each. What kind of combination constitutes the crushing step may be appropriately set depending on the desired particle diameter, the constituent material of the toner particles, and the like. In this case, where to return the coarse powder to be returned to the crushing step may be set appropriately. The multi-division classifier as the second classifying means is not limited to the shape shown in FIG. 12, but an optimum shape depending on the particle size of the pulverized raw material, the particle size of the desired medium powder, the true specific gravity of the powder, and the like. What is good is adopted.

The method for producing a toner of the present invention can be preferably used for producing toner particles used for developing an electrostatic image. To prepare a toner for developing an electrostatic image, a colorant or magnetic powder, a vinyl-based or non-vinyl-based thermoplastic resin, a charge control agent if necessary, and other additives are mixed with a Henschel mixer or a ball mill. After sufficiently mixing with a machine, heating roll, kneader, using a heat kneader such as an extruder, kneading and kneading meat to disperse or dissolve the pigment or dye in which the resins are mutually compatibilized, After cooling and solidification, pulverization and classification can be performed to obtain a toner. The production method of the present invention is used in such a crushing step and a classifying step.

Next, the constituent materials of the toner will be described.
As the binder resin used for the toner, when a heating / pressurizing fixing device or a heating / pressurizing roller fixing device having a device for applying oil is used, the following binder resin for toner can be used.

For example, homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and the like, and their substitution products; styrene-p-chlorostyrene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene. Copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-
Styrene such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer -Based copolymer: polyvinyl chloride, phenol resin, natural resin modified phenol resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin,
Epoxy resin, xylene resin, polyvinyl butyral,
Terpene resin, coumarone indene resin, petroleum resin, etc. can be used.

In the heating / pressurizing fixing method or the heating / pressurizing roller fixing method in which little or no oil is applied, a so-called offset phenomenon in which a part of the toner image on the toner image support member is transferred to the roller, and Adhesion of the toner to the toner image supporting member is an important issue. Toners that fix with less heat energy usually tend to be blocked or caked during storage or in a developing device, so these problems must be taken into consideration at the same time. The physical properties of the binder resin in the toner are most involved in these phenomena. However, according to the research conducted by the present inventors, when the content of the magnetic material in the toner is reduced, the toner image is supported at the time of fixing. Adhesion of the toner to the body is improved, but offset is likely to occur, and blocking or caking is likely to occur. Therefore, the selection of the binder resin is more important when using the heating and pressure roller fixing method in which toner is hardly applied with oil. Preferred binder materials are crosslinked styrenic copolymers or crosslinked polyesters.

Examples of the comonomer for the styrene monomer of the styrene type copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate,
Duplex 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. A monocarboxylic acid having a bond or a substituted product thereof; a dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like; and a substituted product thereof; for example, vinyl chloride, vinyl acetate Vinyl esters such as vinyl benzoate; for example, ethylene-based olefins such as ethylene, propylene and butylene; vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; for example, vinyl methyl ether, Alkenyl ether, such vinyl ethers and vinyl isobutyl ether; vinyl monomers are used singly or two or more.

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

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

In the toner, it is preferable to use a charge control agent by mixing (internally adding) the toner particles. The charge control agent makes it possible to control the optimum charge amount according to the developing system, and in particular, it is possible to further stabilize the balance between the particle size distribution and the charge. It is possible to further clarify the function separation and the mutual complementarity for improving the image quality depending on each particle size range.

As the positive charge control agent, a modified product of nigrosine and a fatty acid metal salt: a quaternary ammonium salt such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate or tetrabutylammonium tetrafluoroborate; Alternatively, two or more kinds can be used in combination. Of these, charge control agents such as nigrosine compounds and quaternary ammonium salts are particularly preferably used. Also, the following general formula

[Chemical 1] (R ₁ in the above formula is H or CH ₃ , and R ₂ or R ₃
Is a substituted or unsubstituted alkyl group (preferably C ₁ -C
₄ )) A monomer homopolymer or a copolymer with a polymerizable monomer such as styrene, acrylic acid ester, and methacrylic acid ester as described above can be used as a positive charge control agent. In addition, these charge control agents also have a function as (all or part of) a binder resin.

As the negative charge control agent, for example, an organometallic complex or a chelate compound is effective, and examples thereof include aluminum acetylacetonate, iron (II) acetylacetonate, and chromium 3,5-ditertiarybutylsalicylate. Or zinc or the like, and acetylacetone metal complex or salt is particularly preferable, and salicylic acid metal complex or salicylic acid metal salt is particularly preferable. It is preferable to use the above-mentioned charge control agent (which does not function as a binder resin) 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 (further, 3 μm or less).

When internally added to the toner, such a charge control agent is preferably used in an amount of 0.1 to 20 parts by weight (more preferably 0.2 to 10 parts by weight) with respect to 100 parts by weight of the binder resin.
When the toner is a magnetic toner, the magnetic material contained in the magnetic toner includes iron oxide such as magnetite, γ-iron oxide, ferrite, iron-excessive ferrite, and the like; metals such as iron, cobalt, and nickel, or these. Alloys of these metals with metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten and vanadium, and mixtures thereof. .

These ferromagnetic materials have an average particle size of 0.1 to 1
μm, preferably about 0.1 to 0.5 μm, and the resin component 1 is contained in the magnetic toner.
60 to 110 parts by weight with respect to 00 parts by weight, and preferably 65 to 100 parts by weight with respect to 100 parts by weight of the resin component.

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

[0068]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. Example 1-Styrene-butyl acrylate-divinylbenzene copolymer (monomer weight ratio 80.0 / 19.0 / 1.0, weight average molecular weight Mw 350,000) 100 parts by weight-Magnetic iron oxide (average particle size 0 .18 μm) 100 parts by weight Nigrosine 2 parts by weight Low molecular weight ethylene-propylene copolymer 4 parts by weight Henschel mixer (FM-75 type,
After mixing well with Mitsui Miike Kakoki Co., Ltd., temperature 15
The kneading was performed with a twin-screw kneader (PCM-30 type, manufactured by Ikegai Tekko KK) set to 0 ° C. The obtained kneaded product was cooled and coarsely pulverized with a hammer mill to 1 mm or less to obtain a coarse powder for toner production. The obtained toner pulverized raw material was pulverized, subjected to low impact treatment and classified by the manufacturing method shown in FIG.

The collision-type airflow crusher uses the device having the structure shown in FIG. 2, and the collision surface has a conical projection with an apex angle of 50 ° (α = 50 °), and the acceleration pipe of the outer peripheral collision surface is The inclination angle of the central axis with respect to the vertical plane was 10 ° (β = 10 °) (α
+ 2β = 70 °). Also, the diameter of the collision member is 90 mm (b
= 90 mm), the distance between the end of the collision surface and the exit of the accelerating pipe is 50 mm (a = 50 mm), the shortest distance to the crushing chamber wall is 20 mm (c = 20 mm), and the crushing chamber shape is box-shaped. went. A forced vortex type airflow classifier was used as the first classifier.

The pulverized raw material was supplied to the air flow classifier at a rate of 31.0 Kg / h by an injection feeder with a table type constant quantity feeder, and the classified coarse powder was supplied to the crushed raw material of the collision type air flow pulverizer. Supplied through mouth 1, pressure 6.0
After being crushed using compressed air of Kg / cm ² (G) and 6.0 Nm ³ / min, it is circulated to the air stream classifier again while being mixed with the toner crushing raw material supplied in the raw material introduction section. Then, closed circuit pulverization was performed to obtain classified fine powder.
The weight average diameter of the fine powder at this time was 8.8 μm, and
It had a sharp particle size distribution substantially not containing 6.0 μm or more.

The particle size distribution of the toner can be measured by various methods, but in this example, it was measured using a Coulter counter. Coulter counter TA as a measuring device
-An interface (made by Nikkaki) and a CX that uses II type (made by Coulter) to output the number distribution and volume distribution
-1 Persol Computer (manufactured by Canon Inc.) is connected, and a 1 wt% NaCl aqueous solution is prepared by using primary sodium chloride as an electrolytic solution. As a measuring method, the electrolytic aqueous solution 100 is used.
Add a surface active agent as a dispersant, preferably 0.1 to 5 ml of alkylbenzene sulfonate, to ~ 150 ml,
Further, 2 to 20 mg of the measurement sample is added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and the Coulter counter TA-II type is used to form particles having a diameter of 2 to 40 μm with a 100 μm aperture as an aperture. The particle size distribution was measured and the values such as the weight average particle size and the number average particle size were obtained.

The fine powder thus obtained was controlled by the low impact treatment device shown in FIG. 9 so that the rotation speed of the rotor was 130 m / sec, the clearance between the liner and the rotor was 2 mm, and the temperature on the outlet side of the device was 40 ° C. The treatment was carried out under the following conditions. Scanned electron microscope (Hitachi S
As a result of observation with -800 type), no significant change was observed in the shape as compared with that before the treatment, but it was confirmed that the angular portion was reduced. The weight average diameter after the treatment was 8.
It was 7 μm.

The fine powder thus treated was classified by a multi-division classifier shown in FIG. At the time of introduction into the multi-division classifier, the suction force generated by the decompression in the system by the suction decompression of the collection cyclone communicating with the discharge ports 111, 112 and 113 and the compression from the injection attached to the raw material supply nozzle 116. I used air. The introduced fine powder was classified in an instant of 0.01 seconds or less. The classified coarse powder was collected by a collection cyclone and then reintroduced into the pulverizer. The weight average particle diameter of the classified medium powder is 8.1 μm.
It has a sharp distribution (contains 0.9% by volume of particles having a particle size of 4.0 μm or less and 0.5% by volume of particles having a particle size of 12.7 μm or more) and is excellent as a toner. Had good performance.

The classified fine powder was returned to the kneading step and reused. At this time, the ratio of the finally obtained intermediate powder to the total amount of the pulverized raw material charged (that is, the classification yield) was 87% by weight. The medium powder finally obtained was observed with an optical microscope, and the ratio of the short diameter to the long diameter was measured and found to be 0.77.

Example 2 Using the same toner pulverization raw material as in Example 1, pulverization, low impact treatment and classification were carried out by the same production method. The collision-type airflow crusher has the structure shown in FIG. 4, and the collision surface has a conical projection with an apex angle of 55 ° (α = 55 °).
The inclination angle of the outer peripheral collision surface with respect to the vertical plane of the central axis of the acceleration tube was 10 ° (β = 10 °) (α + 2β = 75 °).
The diameter of the collision member is 100 mm (b = 100 mm), and the distance between the end of the collision surface and the exit of the acceleration tube is 50 mm (a
= 50 mm) and a cylindrical crushing chamber (c = 25 mm) having an inner diameter of 150 mm was used as the crushing chamber shape. The inclination of the acceleration tube in the long axis direction with respect to the vertical line was substantially 0 °.
Further, as the first classifier, the same device as in Example 1 was used.

47.0 Kg / g of raw material was pulverized with a constant quantity feeder.
The coarse powder supplied to the first classifier at a rate of h and classified was introduced into the collision type airflow crusher, and the pressure was 6.0 kg / cm ^2.
(G), after crushing using 6.0 Nm ³ / min of compressed air, it was circulated through the classifier again and closed circuit crushing was performed. As a result, a finely pulverized product for toner having a weight average diameter of 8.9 μm was obtained as classified fine powder. It should be noted that no stable deposit was generated during the pulverization, and stable operation was possible. This fine powder was treated under the same conditions using the same low impact treatment apparatus as in Example 1. Scanned electron microscope (Hitachi S
As a result of observation with -800 type), no significant change was observed in the shape as compared with that before the treatment, but it was confirmed that the angular portion was reduced. The weight average diameter after the treatment was 8.
It was 8 μm.

This treated fine powder was introduced into the multi-division classifier shown in FIG. 12, and as the classified intermediate powder, the weight average particle size was 8.2 μm (particles having a particle size of 4.0 μm or less were .8
1. Particles containing 1% by volume and having a particle size of 12.7 μm or more
A toner having a sharp distribution of 0% by volume) was obtained with a classification yield of 88% by weight. The classified coarse powder was circulated to the crushing step, and the fine powder was returned to the kneading step for reuse. The medium powder was observed with an optical microscope and the ratio of the short diameter to the long diameter was measured and found to be 0.76.

Example 3 Using the same toner pulverization raw material as in Example 1, pulverization, low impact treatment and classification were carried out by the same production method. The collision type airflow crusher has the configuration shown in FIG. 7, and the shape of the collision surface has a conical projection with an apex angle of 55 ° (α = 55 °).
The inclination angle of the outer peripheral collision surface with respect to the vertical plane of the central axis of the acceleration tube was 10 ° (β = 10 °) (α + 2β = 75 °).
The diameter of the collision member is 100 mm (b = 100 mm), and the distance between the end of the collision surface and the exit of the acceleration tube is 50 mm (a
= 50 mm) and a cylindrical crushing chamber (c = 25 mm) having an inner diameter of 150 mm was used as the crushing chamber shape. The inclination of the acceleration tube in the long axis direction with respect to the vertical line was substantially 0 °, and the pulverized raw material supply port used was one that was open in the entire circumferential direction of the acceleration tube. Further, as the first classifier, the same device as in Example 1 was used.

The pulverized raw material was fed with a constant quantity feeder to 46.0 kg /
It is supplied to the first classifier at a rate of h, and the classified coarse powder is introduced into the collision type airflow crusher, and the pressure is 6.0 Kg / cm ^2.
(G) After crushing using 6.0 Nm ³ / min of compressed air, it was circulated through the classifier again to perform closed circuit crushing. As a result, a finely pulverized product for toner having a weight average diameter of 9.0 μm was obtained as classified fine powder. It should be noted that no stable deposit was generated during the pulverization, and stable operation was possible. This fine powder was treated under the same conditions using the same low impact treatment apparatus as in Example 1.

When the toner after the treatment was observed with a scanning electron microscope (S-800 manufactured by Hitachi, Ltd.), no large change was seen in the shape as compared with that before the treatment, but the angular portion was reduced. Was confirmed. The weight average diameter after the treatment was 8.9 μm. This treated fine powder is shown in FIG.
Introduced into the multi-division classifier of No. 2, as a classified intermediate powder,
It has a sharp weight-average particle size of 8.2 μm (containing 0.8 vol% of particles having a particle size of 4.0 μm or less and 1.2 vol% of particles having a particle size of 12.7 μm or more). The toner was obtained with a classification yield of 86% by weight. The classified coarse powder was circulated to the crushing step, and the fine powder was returned to the kneading step for reuse. The medium powder was observed with an optical microscope and the ratio of the short diameter to the long diameter was measured and found to be 0.76.

Example 4 Using the same toner pulverization raw material as in Example 1, pulverization, low impact treatment and classification were carried out by the same production method. That is, the collision type airflow crusher used the apparatus having the configuration shown in FIG. 2 under the same apparatus conditions as in Example 1. Further, as the first classifier, the same device as in Example 1 was used. The pulverized raw material is fed with a constant quantity feeder 18.
It is supplied to the first classifier at a rate of 0 Kg / h, and the classified coarse powder is introduced into the collision type airflow crusher, and the pressure is 6.0 Kg / c.
After pulverizing with compressed air of m ² (G) and 6.0 Nm ³ / min, it was circulated through the classifier again and closed circuit pulverization was performed. As a result, a weight average diameter of 7.0 as classified fine powder was obtained.
A finely pulverized product for toner having a size of μm was obtained. It should be noted that no stable deposit was generated during the pulverization, and stable operation was possible.

The fine powder was placed in a low impact device shown in FIG. 9 at a rotor rotation speed of 130 m / sec, a liner-rotor clearance of 1 mm, and an outlet temperature of 45 ° C. of the device.
Processed in. When the toner after the treatment was observed with a scanning electron microscope (Hitachi S-800 type), no significant change was seen in the shape as compared with before the treatment, but it was confirmed that the angular portions were reduced. It was The weight average diameter after the treatment was 6.8 μm.

This treated fine powder was introduced into the multi-division classifier shown in FIG. 12 and classified as a medium powder having a weight average particle size of 6.5 μm (particles having a particle size of 4.0 μm or less was 3.0 volume%
A toner having a sharp distribution of 1.0% by volume of particles having a particle size of 10.08 μm or more is obtained with a classification yield of 84% by weight. The classified coarse powder was circulated to the crushing step, and the fine powder was returned to the kneading step for reuse. The medium powder was observed with an optical microscope, and the ratio of the short diameter to the long diameter was measured and found to be 0.80.

Example 5 Using the same toner pulverization raw material as in Example 1, pulverization, low impact treatment and classification were carried out by the same production method. That is, as the collision type airflow crusher, the apparatus having the configuration shown in FIG. 4 was used under the same apparatus conditions as in Example 2. Further, as the first classifier, the same device as in Example 1 was used. 30.
It is supplied to the first classifier at a rate of 0 Kg / h, and the classified coarse powder is introduced into the collision type airflow crusher, and the pressure is 6.0 Kg / c.
After pulverizing with compressed air of m ² (G) and 6.0 Nm ³ / min, it was circulated through the classifier again to perform closed circuit pulverization. As a result, a weight average diameter of 6.9 as classified fine powder was obtained.
A finely pulverized product for toner having a size of μm was obtained. It should be noted that no stable deposit was generated during the pulverization, and stable operation was possible.

The fine powder was treated under the same conditions using the same low impact treatment apparatus as in Example 1. When the toner after the treatment was observed with a scanning electron microscope (Hitachi S-800 type), no significant change was seen in the shape as compared with before the treatment, but it was confirmed that the angular portions were reduced. It was The weight average diameter after the treatment was 6.8 μm.

The treated fine powder was introduced into the multi-division classifier shown in FIG. 12 and classified as a medium powder having a weight average particle size of 6.5 μm (particles having a particle size of 4.0 μm or less was 3.0. volume%
A toner having a sharp distribution of 1.0% by volume of particles having a particle size of 10.08 μm or more is obtained with a classification yield of 84% by weight. The classified coarse powder was circulated to the crushing step, and the fine powder was returned to the kneading step for reuse. The medium powder was observed with an optical microscope, and the ratio of the short diameter to the long diameter was measured and found to be 0.80.

Example 6 Fine powder having a weight average particle size of 8.9 μm obtained in the same manner as in Example 2 was used as a liner with a rotor blade rotating speed of 110 m / sec in a low impact treatment device shown in FIG. The treatment was carried out under the conditions of a rotor blade clearance of 2 mm and an apparatus outlet temperature of 40 ° C. When the toner after the treatment was observed with a scanning electron microscope (Hitachi S-800 type), no significant change was seen in the shape as compared with before the treatment, but it was confirmed that the angular portions were reduced. It was
The weight average diameter after the treatment was 8.8 μm.

This treated fine powder was classified by a multi-division classifier in the same manner as in Example 1, and the classified intermediate powder had a sharp distribution with a weight average particle diameter of 8.2 μm. It had excellent performance as a toner. The classification yield at this time was 86% by weight, and the obtained intermediate powder was observed with an optical microscope to measure the ratio of the short diameter to the long diameter, and it was 0.75.

Comparative Example 1 Using the same toner pulverization raw material as in Example 1, pulverization and classification were carried out according to the flowchart of FIG. As the collision type air flow crusher, the crusher shown in FIG. 14 was used, and the shape of the collision surface was a plane shape perpendicular to the long axis direction of the acceleration tube. The diameter of the collision member is 90 mm (b = 90 m
m), and the distance between the end of the collision surface and the exit of the acceleration tube is 50 m.
m (a = 50 mm), and the shortest distance from the crushing chamber wall is 2
It was 0 mm (c = 20 mm), and the crushing chamber was box-shaped.

As the first classifying means and the second classifying means, a dispersion separator DS5UR (manufactured by Nippon Pneumatic Mfg. Co., Ltd.) was used. 1 crushed raw material with constant quantity feeder
The coarse powder, which was supplied to the DS5UR at a rate of 5.0 Kg / h and was classified, was introduced into the collision type airflow crusher, and the pressure was 6.0 Kg.
/ Cm ² (G), 6.0 Nm ³ / min Compressed air was used for pulverization, and then it was circulated through the classifier again for closed circuit pulverization. As a result, the weight average diameter of the finely divided powder was 7.
A finely pulverized product for toner of 8 μm was obtained. Supply amount 15Kg /
If it is increased to h or more, the volume average diameter of the fine powder obtained will become large, and fusion of the pulverized material, agglomerates and coarse particles will start to occur on the collision member, and the fusion material will clog the raw material supply port of the acceleration tube. In some cases, stable driving was not possible.

When the fine powder was observed with a scanning electron microscope (Hitachi S-800 type), many angular protrusions were found. This fine powder is the second classification means DS
It is supplied to -5UR at a rate of 15.0 Kg / h, and a weight average particle size of 8.4 μm (particles having a particle size of 4.0 μm or less is 2.0.
2. Particles containing 3% by volume and having a particle size of 12.7 μm or more.
A medium powder having a rather broad particle size distribution (containing 2% by volume) was obtained with a classification yield of 68% by weight. The medium powder finally obtained was observed with an optical microscope, and the ratio of the short diameter to the long diameter was measured and found to be 0.65. Compared with Examples 1 to 3, the amount of pulverization treatment and the classification yield were inferior, and the toner surface state had sharp projections.

Comparative Example 2 Using the same toner crushing raw material as in Example 1, crushing and classification were performed by the manufacturing method shown in FIG. As a collision type air flow crusher, the same crusher as in Comparative Example 1 (pressure 6.0 kg / cm)
² (G), 6.0 Nm ³ / min of compressed air was used), and a dispersion separator DS5UR (manufactured by Nippon Pneumatic Mfg. Co., Ltd.) was used as the first classifying means and the second classifying means.

The pulverized raw material was supplied at a rate of 8.0 kg / h to obtain fine powder having a weight average particle diameter of 6.4 μm. When the fine powder was observed with a scanning electron microscope (Hitachi S-800 type), many angular protrusions were found. 8.0 kg of this fine powder was added to DS-5UR which is the second classification means.
/ H, and has a weight average particle diameter of 6.8 μm (containing 5.3 vol% of particles having a particle diameter of 4.0 μm or less and 4.0 vol% of particles having a particle diameter of 10.08 μm or more). ) The intermediate powder having a slightly broad particle size distribution of
Obtained in% by weight. The medium powder finally obtained was observed with an optical microscope, and the ratio of the short diameter to the long diameter was measured and found to be 0.70. Compared with Examples 4 and 5, the pulverization amount and the classification yield were inferior, and the toner surface state had sharp projections.

Example 7 100 parts by weight of unsaturated polyester resin 4.5 parts by weight of copper phthalocyanine pigment (CI Pigment Blue 15) charge control agent (chromium salicylate complex) 4.0 parts by weight Materials of the above formulation Henschel mixer (FM-75 type,
After mixing well with Mitsui Miike Kakoki Co., Ltd., temperature 10
Kneading and dispersion were performed with a twin-screw kneader (PCM-30 type, manufactured by Ikegai Tekko Co., Ltd.) set at 0 ° C. The obtained kneaded product was cooled and coarsely pulverized with a hammer mill to 1 mm or less to obtain a coarse powder for toner production. The obtained toner pulverized raw material is shown in FIG.
By the manufacturing method shown in (1), crushing low impact treatment and classification were performed.

The collision type airflow crusher uses the device having the structure shown in FIG. 4, and the collision surface has a conical projection having an apex angle of 55 ° (α = 55 °), and the acceleration pipe of the outer peripheral collision surface is The inclination angle of the central axis with respect to the vertical plane was 10 ° (β = 10 °) (α
+ 2β = 75 °). Also, the diameter of the collision member is 100 mm
(B = 100 mm), the distance between the end of the collision surface and the outlet of the acceleration tube was 50 mm (a = 50 mm), and the crushing chamber was a cylindrical crushing chamber (c = 25 mm) having an inner diameter of 150 mm. The inclination of the acceleration tube in the long axis direction with respect to the vertical line was substantially 0 °. Further, as the first classifier, the same device as in Example 1 was used.

43.0 kg / min of pulverized raw material with a constant quantity feeder
It is supplied to the first classifier at a rate of h, and the classified coarse powder is introduced into the collision type airflow crusher, and the pressure is 6.0 Kg / cm ^2.
(G), after crushing using 6.0 Nm ³ / min of compressed air, it was circulated through the classifier again and closed circuit crushing was performed. As a result, a finely pulverized product for toner having a weight average diameter of 8.0 μm was obtained as classified fine powder. It should be noted that no stable deposit was generated during the pulverization, and stable operation was possible. This fine powder was treated under the same conditions using the same low impact treatment apparatus as in Example 1. Scanned electron microscope (Hitachi S
As a result of observation with -800 type), no significant change was observed in the shape as compared with that before the treatment, but it was confirmed that the angular portion was reduced. The weight average diameter after the treatment was 7.
It was 8 μm.

This treated fine powder was introduced into the multi-division classifier shown in FIG. 12 to be classified as a medium powder having a weight average particle diameter of 8.2 μm (particles having a particle diameter of 4.0 μm or less are less than 0.2 μm). Particles containing 6% by volume and having a particle size of 12.7 μm or more are 1.5
A toner having a sharp distribution of (containing by volume%) was obtained with a classification yield of 80% by weight. The classified coarse powder was circulated to the crushing step, and the fine powder was returned to the kneading step for reuse. The medium powder was observed with an optical microscope, and the ratio of the short diameter to the long diameter was measured and found to be 0.75.

Comparative Example 3 Using the same toner pulverization raw material as in Example 7, pulverization and classification were carried out according to the flowchart of FIG. The crusher shown in FIG. 14 was used as the collision type airflow crusher, and the shape of the collision surface was a plane shape perpendicular to the long axis direction of the acceleration tube. The diameter of the collision member is 90mm (b = 90mm)
And the distance between the end of the collision surface and the exit of the acceleration tube is 50 mm.
(A = 50 mm), and the shortest distance to the crushing chamber wall is 20
mm (c = 20 mm), and the crushing chamber was box-shaped. As the first classification means and the second classification means, a dispersion separator DS5UR (manufactured by Nippon Pneumatic Mfg. Co., Ltd.) was used.

18.0 Kg / g of pulverized raw material was fed with a constant quantity feeder.
The coarse powder fed to the DS5UR at a rate of h and classified was introduced into the collision type airflow crusher, and the pressure was 6.0 kg / cm ^2.
(G), after crushing using 6.0 Nm ³ / min of compressed air, it was circulated through the classifier again and closed circuit crushing was performed. As a result, a finely pulverized product for toner having a weight average diameter of 7.5 μm was obtained as classified fine powder. When the supply amount is increased to 18 kg / h or more, the volume average diameter of the fine powder obtained increases, and
Stable operation could not be performed because the fused material, the agglomerated material, and the coarse particles of the crushed material may start to be generated on the collision member, and the fused material may clog the raw material supply port of the acceleration tube.

When the fine powder was observed with a scanning electron microscope (Hitachi S-800 type), many angular protrusions were found. This fine powder is used as the second classification means D
It was supplied to S-5UR at a rate of 18.0 Kg / h, and a weight average particle diameter of 8.0 μm (particles having a particle diameter of 4.0 μm or less was 1.
A medium powder having a slightly broad particle size distribution of 5% by volume and 3.3% by volume of particles having a particle size of 12.7 μm or more was obtained with a classification yield of 62% by weight. The medium powder finally obtained was observed with an optical microscope, and the ratio of the short diameter to the long diameter was measured and found to be 0.65. Compared with Example 7, the amount of pulverization and the classification yield were inferior, and the toner surface state had sharp projections.

[0101]

According to the method for producing a toner for developing an electrostatic charge image of the present invention, a toner having a small particle size can be efficiently produced by a specific jet mill having high impact and good pulverization efficiency, and By the low impact treatment step, a good quality toner having excellent fluidity can be obtained. Further, there is an advantage that fusion, aggregation and coarsening of the toner pulverized product in the toner manufacturing process can be prevented, apparatus abrasion due to the toner component can be prevented, and continuous and stable production can be performed. Further, by using the toner manufacturing method of the present invention, the image density is stable and high as compared with the conventional method, the durability is good, and an electrostatic charge image having an excellent predetermined grain size without image defects such as fog and cleaning failure. The developing toner can be obtained at low cost. In particular, there is an advantage that a toner having a weight average particle diameter of 9 μm or less can be effectively obtained.

[0102]

[Brief description of drawings]

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

FIG. 2 is a schematic cross-sectional view of a specific example of a collision type air flow pulverizing means for carrying out the manufacturing method of the present invention.

FIG. 3 is a cross-sectional plan view of the grinding chamber in FIG.

FIG. 4 is a schematic cross-sectional view showing another specific example of the collision type air flow pulverizing means for carrying out the manufacturing method of the present invention.

5 is a cross-sectional view taken along the line A-A ′ in FIG.

6 is a cross-sectional view taken along the line B-B ′ in FIG.

[0103]

FIG. 7 is a schematic cross-sectional view showing another specific example of the collision type air flow pulverizing means for carrying out the manufacturing method of the present invention.

8 is a cross-sectional view taken along the line C-C ′ in FIG. 7.

FIG. 9 is a schematic cross-sectional view showing a specific example of a low impact treatment device for carrying out the manufacturing method of the present invention.

10 is a diagram showing a positional relationship between a learner and a rotor of the apparatus shown in FIG.

FIG. 11 is a schematic cross-sectional view showing another specific example of the low impact treatment apparatus for carrying out the manufacturing method of the present invention.

[0104]

FIG. 12 shows a cross-sectional view of a specific example of the classification device used in the present invention.

FIG. 13 is a flow chart diagram for explaining a conventional manufacturing method.

FIG. 14 is a schematic sectional view of a collision type air flow pulverizing means used in a conventional manufacturing method.

FIG. 15 is a schematic cross-sectional view of another collision type air flow pulverizing means used in the conventional manufacturing method.

FIG. 16 is a schematic cross-sectional view of another collision type air flow pulverizing means used in the conventional manufacturing method.

FIG. 17 is a schematic cross-sectional view of another collision type air flow pulverizing means used in the conventional manufacturing method.

[0105]

[Explanation of sign]

 1: Grinding material supply port 2: Compressed gas supply nozzle 3: Acceleration pipe 4: Collision member 5: Discharge port 6: Grinding chamber side wall 7: Grinding material 8: Grinding chamber 11: Grinder wall 13: Acceleration pipe outlet 14: Projection Central part 15: Perimeter collision surface 16: Collision surface

21: Acceleration tube 22: Acceleration tube throat section 23: High pressure gas jet nozzle 24: Ground material supply port 25: Ground material supply tube 26: High pressure gas supply port 27: High pressure gas chamber 28: High pressure gas introduction tube 29: Accelerator pipe outlet 30: Collision member 32: Grinding chamber side wall

33: crushed product outlet 34: crushing chamber 35: Laval nozzle 36: accelerating pipe throat part 37: accelerating pipe outlet 38: return path 39: raw material supply port 40: inlet 41: jacket 42: return closing valve 43: rotating shaft 44: Casing 45: Liner

46: blower blade 47: rotor 48: outlet 49: product outlet 51: casing 52: rotor 53: blade 54: liner 55: treatment area 56: input material 57: inflow air 58: supply port 59: swirl chamber

60: Distributor 61: Discharge port 111: Discharge port 112: Discharge port 113: Discharge port 114: Inlet pipe 115: Inlet pipe 116: Raw material supply nozzle 117: Classification edge 118: Classification edge 119: Inlet edge 120 : First gas introduction adjusting means 121: Second gas introduction adjusting means

122: Side wall 123: Lower wall 124: Side wall 125: Lower wall 126: Coanda block 127: Upper wall 128: Static pressure meter 129: Static pressure meter 130: Particle trajectory

Front Page Continuation (72) Inventor Satoshi Mitsumura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (2)

[Claims] 1. A mixture containing at least a binder resin and a colorant is melt-kneaded, the kneaded product is cooled, and the cooled product is crushed by a crushing device to obtain a crushed product. To classify into coarse powder and fine powder, and finely pulverize the classified coarse powder by collision type air flow pulverizing means to produce fine powder,
In the method of classifying fine powder from the generated fine powder by air flow classification means, and manufacturing electrostatic toner image developing toner from the classified fine powder, the collision type air flow grinding means accelerates conveyance of the object to be ground by high pressure gas. A pulverizer having an accelerating tube for crushing and a crushing chamber for crushing the object to be crushed, which is supplied into the accelerating tube and discharges the accelerated object to be crushed into the crushing chamber from the acceleration tube outlet, Primary crushing is performed by the projecting portion of the collision member having a collision surface provided facing the opening surface of the outlet of the acceleration tube, and the primary crushed primary pulverized product is crushed by the outer peripheral collision surface provided on the outer periphery of the projecting portion. After secondary pulverization and secondary pulverization, the secondary pulverized material is further tertiary pulverized on the side wall in the pulverization chamber, and then circulated to the first air stream classification means to obtain fine powder classified by the first air stream classification means. Apart from the crushing process, the impact type air flow crushing means has a relatively low impact. A method for producing a toner for developing an electrostatic charge image, which comprises adjusting a particle size by a second classifying means after giving a time. 2. When the apex angle of the projecting central portion projecting on the collision surface of the collision member is α (°) and the inclination angle β (°) of the outer peripheral collision surface with respect to the vertical plane of the central axis of the acceleration tube, The method for producing a toner according to claim 1, wherein the α and the β satisfy the following formulas 0 <α <90, β> 0 30 ≦ α + 2β ≦ 90.