JP2002136923A - Ultrasonic vibration sieve and method for manufacturing electrophotographic toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic vibration sieve capable of performing long- term stable sieving without generating mesh clogging even if a specific material easy to generate mesh clogging is used and a method for manufacturing electrophotographic toner using the same. SOLUTION: In the ultrasonic vibration sieve applying vibration due to a vibration motor and fine vibration due to ultrasonic waves to a surface to separate a material to be sieved into a fine powder and a coarse powder, a wiping member 150 for wiping off the material to be sieved remaining on the surface of a net 108 is provided. The sieving process in a toner manufacturing process is performed using the ultrasonic vibration sieve to manufacture electrophotographic toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic vibrating sieve utilizing vibration by a vibration motor and microvibration caused by ultrasonic waves, and a method for producing a toner for electrostatic charge development incorporating the sieve in a toner sieving step. .

[Prior art]

Heretofore, electrophotographic toners have been obtained by a kneading and pulverizing method in which a thermoplastic resin is melt-kneaded together with a releasing agent such as a pigment, a charge controlling agent, and a wax, cooled, finely pulverized, and further classified. The toner particles are obtained by mixing an organic or inorganic external additive with the toner particles and finally removing coarse particles by a sieving step.

The sieving process in the toner production process is performed to remove toner aggregates and other foreign matters. Recently, high image quality has been demanded, and the sieve opening tends to be reduced at the same time as the toner particle size is reduced. Conventionally, when sieving with a mesh having a small mesh size of about 20 to 50 μm, a wind sieving apparatus has been used. However, the wind sieving machine forcibly passes the material through the net by suction air, and the clogging of the net is removed by blowing high-speed compressed air discharged from a backwash nozzle on the back side of the net. For this reason, the net and the material are greatly damaged, and a fusion substance and an aggregate of the external additive are generated on the net surface, and coarse powder is mixed into the sieved toner. When the toner mixed with the coarse powder is put into a copying machine or a printer for operation, there is a concern that the aggregates may be clogged in the trimmer gap of the developing machine. When aggregates are clogged in the trimmer gap,
Since the developer is not conveyed to that portion, a portion where the developer does not get streaked on the mag roll occurs. Then, when the portion is printed, it is stripped off and the copy image quality is reduced. Also, if the aggregates are transported without clogging at the trimmer gap, the aggregates will be abnormally charged on the photoreceptor, causing white spots or defects very similar to grit on the print, resulting in copy image quality. Causes a drop in Furthermore, the wind sieving machine requires dust collection equipment such as a cyclone, and thus has problems such as dust collection loss and enlargement of incidental equipment.

Therefore, recently, an ultrasonic vibrator has been installed on a net frame of a circular vibrating sieve or a gyro shifter to which the vibration of a conventional vibrating motor has been applied, and the ultrasonic vibration has been propagated on the net surface, thereby increasing the processing capacity. Attention has been paid to ultrasonic vibrating sieves that have improved and improved clogging removal performance, and are widely used in toner manufacturing processes.

The general structure of this ultrasonic vibrating sieve is shown in FIG.
Shown in In FIG. 12, a cylindrical sieve frame 104 supported by a plurality of coil springs 102 is provided on a base frame 100, and a conical bottom 106 shown by a broken line is formed inside the sieve frame 104. In addition, this sieve frame 1
An annular support frame 110 on which a sieve mesh 108 is stretched is fixed to 04. Further, although not shown in FIG. 1, the base frame 100 has a built-in vibration motor,
The operation of the vibration motor causes the coil spring 102 to operate.
The entire upper sieve frame can be vibrated.

A resonance ring 112 having a smaller diameter than the sieve frame 104 is fixed to the lower surface of the sieve mesh 108, and an ultrasonic transducer 114 is installed on the resonance ring 112.
The ultrasonic vibrator includes one that is welded to the resonance ring 112 and one that is detachable. A sieve fraction collection port 116 is provided on a side surface of the cylindrical sieve frame 104 at a position corresponding to the upper surface of the bottom portion 106. Further, a coarse powder discharge port 120 is formed in an annular support frame 110 on which a sieve mesh 108 is stretched.
Frame 105 having outer peripheral surface and material to be sieved supply port 1
An upper cover 122 having an 18 is detachably disposed.

In this ultrasonic vibrating sieve, the material to be sieved (for example, the toner is supplied to the apparatus from the material to be sifted supply port 118 by means of a vibrating motor and the ultrasonic vibrator simultaneously Ring 112 by the operation of
The coarse powder is sieved by the fine vibration of
And the fines pass through the sieve frame 108 and pass through the bottom 106
Is discharged from the sieve fraction collection port 116.

[0008] The ultrasonic vibrating sieve causes less damage to the material than a wind sieve. Therefore, there is an advantage that the externally added fine particles are hardly peeled off or buried in the toner, and additional equipment such as a blower and a dust collector is not required.

[0009] However, the ultrasonic vibrating sieve is not provided with a strong mesh clogging removing mechanism such as a backwash nozzle in a wind sieving machine, and is provided on a metal surface such as silica oil-treated silica and zinc stearate. When a toner in which a specific material which is easily adhered is externally or internally added is sieved, such a material adheres to the net, and finally there is a problem that the operation becomes impossible due to clogging of the net.

On the other hand, as means for preventing such mesh clogging, Japanese Patent Application Laid-Open Nos. 11-207262 and
In Japanese Patent Application Laid-Open No. 1-253883, a method is proposed in which a floating brush is installed on a net, and the clogging is removed while the brush is turned on the net in a direction perpendicular to the net by the vibration of a vibration motor. However, since such a floating brush is in contact with the mesh surface at many points, there are many portions that do not contact the mesh in a single pass, and the clogging removal performance is low. Further, in order to sufficiently exhibit the removal performance, it is necessary to make the brush stand upright to the net surface. In this case, the brush is required to have an appropriate hardness, but when the hardness is increased, a problem occurs in that the brush jumps due to vibration of a mesh surface. When such a phenomenon occurs, the performance of removing clogging is reduced, and the net is damaged, leading to breakage of the net.

Particularly, in the step of sieving the toner for electrophotography, a screen having a relatively small mesh diameter and a relatively small mesh is used.
There is a problem that the life of the net is reduced by the brush jumping.

[0012]

[Problems to be solved by the invention]

An object of the present invention is to solve the conventional problems and achieve the following objects. That is, an object of the present invention is to produce an ultrasonic vibrating sieve which can be sieved stably for a long period of time without causing mesh clogging even when a specific material which is easily clogged is used, and production of an electrophotographic toner using the same. It provides a method.

[0014]

Means for Solving the Problems The inventors of the present invention have made intensive studies so that clogging can be continuously removed without damaging the mesh, and as a result, the above-mentioned problem can be solved. That is, the configuration of the present invention is as follows.

(1) Vibration caused by a vibration motor on a net surface;
In the ultrasonic vibrating sieve which gives fine vibrations by ultrasonic waves and separates the material to be sieved into fine powder and coarse powder, the material to be sieved which is arranged movably on the mesh surface and remains on the mesh surface is removed. An ultrasonic vibration sieve comprising a wiping member for wiping. (2) A method for producing a toner for electrophotography, wherein the ultrasonic vibration sieve according to (1) is used in a sieving step of the toner production step.

According to the invention described in the above (1), the material to be sieved (for example, adheres to the mesh surface or is clogged) remaining on the mesh surface by the wiping member moving on the mesh surface. Material to be sieved) can be wiped off. In addition, the wiping member is a member having flexibility that can follow the net surface, has a large area in contact with the net surface, and without damaging the net surface because it moves in almost contact.
The remaining material to be sieved can be efficiently wiped off.

According to the invention (2), the toner is used in the sieving step of the toner production step, particularly, the externally added toner particles, and the toner particles having a predetermined particle size are sieved.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the ultrasonic vibrating sieve of the present invention will be described below with reference to the drawings. In the following, the components denoted by the same reference numerals in the drawings have the same functions, and thus description thereof may be omitted.

(First Embodiment) FIG. 1 is a schematic configuration diagram showing a first embodiment of an ultrasonic vibrating sieve of the present invention, and FIG. It is a schematic structure figure in an ultrasonic vibration sieve. FIG. 3 is a schematic diagram showing a specific example of the wiping member, and FIG. 4 is a conceptual diagram of the removal of deposits and clogging by the material to be sieved on the mesh surface by the wiping member. Note that components substantially the same as those of the device shown in FIG. 11 are denoted by the same reference numerals, and a description of the configuration will be omitted.

In the first embodiment (see FIGS. 1 and 2), four wiping members 150 are arranged on the screen 108. The four wiping members 150 are fixed to ends of a cross-shaped support member 152 installed to prevent deformation. The support member 152 is rotatable about an axis perpendicular to the center of the screen 108. Sieve mesh 10
A triangular pyramid-shaped dispersion cone 156 that functions as a buffer when supplying the material to be sieved is provided at the upper part of the center of the eight surfaces.

The wiping member 150 is, for example, as shown in FIG.
It can be fixed to the support 152 as shown in FIGS. FIG. 3A shows an example of a wiping member 150 in which a cloth 150 a such as a woven cloth or a nonwoven cloth is wound around a support member 152. FIG. 3 (B) shows a sponge 150b on the support 152.
An example of a wiping member 150 in which a cloth 150a such as a woven cloth and a nonwoven cloth is wound around the fixing member 150 is shown. FIG. 3 (C)-
(E) shows an example of the wiping member 150 in which the sponges 150b are fixed to the support member 152. Also, the wiping member 1
50 may have irregularities as shown in FIGS. 3 (D) to (E).

The material of the wiping member 150 is not particularly limited as long as it has a flexibility that can follow the sieve mesh. For example, cotton, rayon, polyester,
Woven and non-woven fabrics made mainly of nylon fibers and the like; sponges such as polyethylene foam sponge, urethane foam sponge, rubber sponge, polyvinyl acetal sponge; and the like. In particular, a material having conductivity (for example, sponge or the like having conductivity by mixing conductive cloth such as "Tenabel (manufactured by Teijin Limited)" or carbon) is at least sieved with a sieve mesh. By using it in the contact area, it is possible to prevent adhesion and clogging due to the generation of static electricity due to friction between the net, the material, and the wiping member even when sieving a material that is easily electrostatically attached such as toner. Become.

The support member 152 only needs to have appropriate rigidity so that the wiping member does not significantly deform.
About the shape etc. and the connection method with the wiping member etc.,
The present invention is not particularly limited. here,
As a method of turning the support member 152 (wiping member 150), a method of directly turning using a driving device such as a motor, a method of turning indirectly through a sieve mesh by vibration of a sieve main body, and the like can be given. The present invention is not particularly limited.

Next, the operation of the first embodiment will be described. The material supplied from the material to be sieved supply port 118 is
It falls on a sieve mesh 108 and is
Vibration by the vibration motor 130 incorporated therein and fine vibrations generated by the action of the ultrasonic vibrator 114 pass through the sieve mesh 108 in order from the portion close to the sieve mesh 108 while being loosened, and are sieved as sieve fractions. It is collected from the product collection port 116. Coarse powder that does not pass through the sieve screen 108 is coarse powder outlet 1
Discharged from 20. The net adhesion and clogging generated at this time are continuously removed by the wiping member 150.
The wiping member 150 is provided with an external force (for example, as shown in FIG. 4).
The micro-vibrator 114 receives a micro-vibration by the ultrasonic vibrator 114 or a driving device such as an optionally provided motor, etc.
While the entire lower surface of the wiping member 150 is in contact with the sieve mesh,
It moves on the sieve screen 108. At this time, the deposits on the net surface and the clogging 158 are removed by the frictional force and the attraction force of the wiping member 150. Wipe member 15 unlike brush
No. 0 follows and is in contact with all the nets located on the lower surface of the member and moves almost in contact with the sieve net 108, so that the efficiency of removing the net clogging is high and the net is hardly damaged.

Incidentally, in order to sufficiently obtain the effects of the present invention,
It is desirable to use a sieve mesh 108 having a mesh size of 20 to 106 μm, a relatively small mesh size and a small wire diameter. By using a net having a small wire diameter, the relative area where the wiping member 150 is in contact with one wire is increased,
The effect of removing clogging increases. Therefore, when the mesh size of the mesh is A (μm) and the wire diameter of the mesh is d (μm), 4 ≦ d
² / (A + d) ≦ 14, more preferably 5 ≦ d ² / (A
+ D) It is desirable to use a net that satisfies the range of ≦ 11. Under the condition that d ² / (A + d) is larger than 14,
Since the wire diameter of the mesh is larger than that of the mesh opening, the wiping member 150 hardly comes into contact with the clogging caught between the wires, so that a sufficient effect cannot be exhibited, and the removal performance may be reduced. is there. Also, d ² / (A + d) is 4
Under smaller conditions, the strength of the net per unit area may be too low and the net may be easily broken. In addition, examples of the material of the sieve mesh 108 generally include stainless steel, nylon, polyester, and a synthetic fiber net having conductivity.

(Second Embodiment) FIG. 5 is a schematic configuration diagram showing a second embodiment of the ultrasonic vibrating sieve of the present invention, and FIG. It is a schematic structure figure on a sieve net in an ultrasonic vibration sieve. FIG. 7 shows a schematic configuration diagram near the wiping member. It should be noted that components substantially the same as those of the apparatus shown in FIG.

In the second embodiment (see FIGS. 5 and 6), an upper frame 160 and an upper lid 162 are detachably disposed on an annular support frame 110 on which a sieve mesh 108 is stretched. On the upper surface of the upper lid 162 disposed on the upper frame 160, a material supply port 164 to be sieved is disposed close to the support frame 110 side (closer to the outer periphery of the sieve mesh 108). , A tubular coarse powder discharge port 166 disposed close to the center of the screen 108. This coarse powder discharge port 166 is connected to a suction device and a suction pipe (not shown) via an automatic valve 168. Further, a built-in vibration motor similar to that of the first embodiment is provided in the base frame.

In the second embodiment, as shown in FIG. 7, the center axis of the support member 152 for fixing the wiping member 150 is integrated with the support ring 170, and the support ring 170 discharges coarse powder. An outlet 166 extends through. The support ring 170 and the coarse powder discharge port 166 are fitted with each other, and have an appropriate clearance so that the support member 152, that is, the wiping member 150 can be turned. The support 152 is
A support ring 170 is disposed between the upper fixed ring 172 and the lower fixed ring 174, and is supported by the spring 176 from the lower fixed ring 174 side, that is, supported by being held between the upper fixed ring 172 and the spring 176. By appropriately adjusting the elastic modulus of the spring 176, the pressing force of the wiping member 150 against the sieve mesh 108 can be adjusted. In the present invention, it is not limited to the spring 176, and an elastic member (for example, rubber or the like) may be used. In addition, the support member 152 is provided on the upper fixing ring 1.
Support ring 170 between the lower fixing ring
May be disposed and supported by the spring 176 from the upper fixing ring 172 side, that is, supported by being held between the spring 176 and the lower fixing ring 174.

In the second embodiment, as shown in FIG. 7, when the material to be sieved is supplied into the material supply port 164 to be sieved, the material is not supplied directly to the screen 108 of the screen. , A buffer plate 178 is provided. Buffer plate 178
Are provided to be inclined with respect to the screen 108 surface. After the material to be sieved once hits the buffer plate 178, the sieve mesh 1
08, the sieve mesh 108 of the material to be sieved.
Can be reduced. Therefore, damage to the sieve mesh 108 due to the supply of the material to be sieved can be reduced.

In the second embodiment, as shown in FIG. 8, an air nozzle 180 for jetting compressed air toward the mesh surface may be provided above the sieve mesh 108. The air nozzle 180 is desirably a tubular air nozzle that is positioned horizontally with respect to the screen 108 and has a slit for discharging compressed air or a discharge port provided with a number of pores on the outer peripheral surface of the pipe. By discharging compressed air to the surface of the sieve mesh 108 and the wiping member 150 by the air nozzle 180, dirt on the wiping member 150 and the sieve mesh 108 can be simultaneously removed. By removing the dirt from the wiping member 150, the wiping member 1 which has been reduced over a long period of use is used.
The clogging removal performance of 50 is restored. This air nozzle 1
The nozzle 80 may be arranged so as to be jetted perpendicularly to the screen 108, but it is arranged so as to be jetted at an angle to the screen 108 (for example, the air nozzle 180 is connected to its central axis with the screen). It is preferable that the surface of the screen 108 is inclined or the air nozzle 180 is arranged so that the central axis of the discharge port and the surface of the screen 108 are inclined. As described above, by using the tubular air nozzle 180 having the inclined discharge direction, that is, by injecting the compressed air while being inclined with respect to the screen 108, the compressed air is discharged widely in the radial direction of the screen 108, The force applied to the net by the compressed air can be reduced, and the stain on the wiping member 150 can be efficiently removed while suppressing the net from being loosened by the compressed air. Further, a plurality of air nozzles 180 can be provided, and by providing a plurality of air nozzles 180, the efficiency of removing dirt can be further improved. In the present invention, the discharge frequency and discharge timing of the compressed air are not particularly limited. In particular, when the suction force is used for discharging the coarse powder as in the second embodiment, the compressed air is discharged when the coarse powder is discharged. By discharging the liquid, the discharge of the coarse powder and the removal of the dirt from the wiping member can be performed at the same time.

Next, the operation of the second embodiment will be described. The material to be sieved is supplied from the material supply port 164 to be sieved, and moves toward the center while rotating on the screen 108. As will be described later, the vibration by the vibration motor 130 built in the base frame 100 and the ultrasonic vibrator 1
While being loosened by the micro-vibration generated by the action of 14, the portion passes through the sieve mesh 108 in order from the portion adjacent to the sieve mesh 108 and is collected from the sieve fraction collection port 116 as a sieve fraction.
At this time, it is desirable that the sieve mesh 108 be vibrated at such a setting that the material is gathered at the center (described later). As a result, coarse powder that does not pass through the sieve mesh 108 is collected at the center of the mesh. This coarse powder is sucked and removed from the coarse powder outlet 166. It is desirable that the suction operation of the coarse powder discharge port 166 be stopped when the material to be sieved is supplied, and that the coarse powder be periodically sucked and removed from the coarse powder discharge port 166. The deposits and clogging of the sieve mesh generated by the series of sieving operations are continuously removed as in the first embodiment. In the second embodiment, the wiping member 150
The material to be sieved on the sieve mesh 108 moves in the outer circumferential direction of the sieve mesh 108 by receiving a force in the outer circumferential direction of the screen 108. The coarse powder discharge port 166 is provided at the center position of the upper lid 162,
By stopping or reducing the supply of the raw material, coarse powder can be selectively collected at the center of the screen 108 and discharged, so that it is possible to remove mesh clogging without lowering the yield of the sieved product. Become.

FIGS. 8 and 9 schematically show an example of the vibration motor built in the base frame 100 in the first and second embodiments. This vibration motor 130
A circular weight mounting plate 134 having an arc-shaped hole 132 on the output shaft of the actuator and an arc-shaped hole 132 so that the output shaft of the vibration motor 130 can be fixed at an arbitrary angle (weight phase angle). A weight 138 fixed by a penetrating weight fixing bolt 136, and a refill weight 14 removably fixed to the weight 138 by a weight fixing bolt 140.
2 is provided. An upper weight whose center of gravity is decentered with respect to the shaft is also fixed to the shaft above the vibration motor (not shown), and the vibration behavior is changed by changing the phase angle of the upper and lower weights of the vibration motor 130 shaft. Can be done.

The powder contact surface in the apparatus is desirably coated by buffing or composite plating. As the fine particles contained in the composite plating film, fine particles of a fluorine-containing compound excellent in various properties such as self-lubricating property, low friction property, water repellency, oil repellency, and non-adhesiveness are particularly preferable. The fluorinated compound can be appropriately selected according to the purpose. For example, fluorinated graphite, fluororesin, fluorinated pitch and the like are preferably used.

In order to vibrate on the screen 108 such that the materials are gathered at the center (conversely, the materials are gathered on the outer periphery), it is preferable to control the vibration motor 130 as follows. In this vibration motor 130, the weight phase angle θ _W
For but 0 °, but the material on the sieve screen 108 is moved in a straight line toward the outer side from the center of the sieve screen 108, a rotational component to the movement of the material on the sieve screen 108 as widening the weight phase angle theta _W give. When the weight phase angle θ _W exceeds about 40 degrees, the material on the screen 108 flows toward the center of the screen 108. Therefore, coarse powder discharge port 1
In the first embodiment in which 20 is provided on the outer peripheral surface of the upper frame 105 (natural discharge), it is desirable that the phase angle of the vibration motor 130 be about 0 to 40 degrees. On the other hand, in the second embodiment, the material supply port 164 to be sieved is provided near the outer periphery of the screen 108 and the coarse powder discharge port 166 is provided at the center of the screen 108 (for example, batch suction).
The phase angle of 30 is 40 to 90 degrees, preferably 65 to 8
Desirably, it is 0 degrees. By controlling in this way, in the second embodiment, as shown in FIG.
08 will flow toward the center of the screen 108. In order to move the material to be sieved to the center of the screen 108, at least a phase angle of 40 degrees or more is required. , And it becomes difficult to sieve using the entire net, which may cause a problem such as a reduction in processing capacity.

Although it depends on the vibration of the ultrasonic vibrator 114, for example, the vibration frequency of the ultrasonic vibrator 114 is desirably 25 to 45 kHz, preferably 30 to 40 kHz. If the vibration frequency is less than 25 kHz, it is not enough to loosen the cohesion of the materials to be sieved, and if the vibration frequency exceeds 45 kHz, there is a problem that the mesh deteriorates and the temperature of the mesh surface rises.

In the first and second embodiments, the wiping member 150 is configured to move on the sieve screen by swirling, but the present invention is not limited to this. , A reciprocating motion typified by a wiper or the like may be used to move on a sieve mesh.

In the method for producing a toner for developing an electrostatic image of the present invention, other points are not particularly limited as long as the ultrasonic vibration sieve of the present invention is used for sieving toner particles.
It can be carried out according to a toner production method known per se.

As the raw material of the toner for developing an electrostatic latent image produced in the present invention, known materials are used, and as the binder resin, styrenes such as styrene and chlorostyrene;
Monoolefins such as ethylene, propylene, butylene and isoprene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate Α-methylene aliphatic monocarboxylic esters such as phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether; vinyl methyl Ketones, vinyl hexyl ketones, vinyl ketones such as vinyl isopropenyl ketone, and homopolymers or copolymers thereof can be exemplified. Particularly typical binder resins include polystyrene and styrene- Alkyl copolymer acrylic acid, styrene - alkyl methacrylate copolymer, styrene - acrylonitrile copolymer, styrene - butadiene copolymer,
Styrene-maleic anhydride copolymer, polyethylene, polypropylene and the like can be mentioned. Further, polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like can be mentioned.

Examples of coloring agents include carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, and rose bengal. , C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 122, C.I.
I. Pigment Red 57: 1, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 12,
C. I. Pigment Yellow 180, C.I. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 1
5: 3 and the like can be exemplified as typical ones.

In the production of the toner of the present invention, a charge control agent may be added as required. As the charge control agent, known ones can be used. However, high charge control agents such as a fluorine-containing surfactant, a metal-containing dye such as a salicylic acid metal complex and an azo-based metal compound, and a copolymer containing maleic acid as a monomer component can be used. A molecular acid, a quaternary ammonium salt, an azine dye such as nigrosine, carbon black, a charge control resin and the like are used, and a salicylic acid complex of Zn and Al and a quaternary ammonium salt are particularly preferable. These are used in the range of 0.1 to 10% by weight.

In the production of the toner according to the present invention, a releasing agent may be added for the purpose of improving the offset resistance. The release agent is preferably a paraffin having 8 or more carbon atoms, polyolefin, or the like. Examples thereof include paraffin wax, paraffin latex, microcrystalline wax, polypropylene, and polyethylene. These can be used alone or in combination. The amount of these additives is preferably in the range of 0.3 to 10% by weight.

In the present invention, first, the above-mentioned raw materials for toner production are melt-kneaded, and the kneaded material is pulverized. As the melt kneader used in the present invention, a known kneader such as a kneader, an extruder, and a Banbury mixer is used. Further, in the present invention, as a pulverizer, a collision type jet pulverizer, a facing type jet pulverizer such as AFG, KT
Although a mechanical pulverizer such as M can be generally used, even a pulverizer having a built-in coarse powder classifier inside the pulverizer,
Even if a centrifugal coarse particle classifier is arranged outside the pulverizer and a closed circuit is incorporated as a system, there is no problem.

The pulverized material is collected by a cyclone and then classified. The classification step may include two steps of classification and sieving. The classifier used in the present invention may be a centrifugal classifier such as Accucut or TTSP, or a classifier using inertial force such as an elbow jet. The classified material is collected by a cyclone and becomes a classified product.

The toner used in the present invention includes:
A step of mixing a resin fine particle dispersion and a colorant dispersion proposed in JP-A-2000-131876 to aggregate the resin fine particles and the colorant particles to form an aggregate particle dispersion; Heating the dispersion above the glass transition temperature of the resin microparticles, washing the toner slurry obtained through the step of fusing and coalescing the aggregated particles,
It may be filtered and dried.

In the present invention, inorganic fine particles such as silica or titania may be added and mixed as an external additive for the purpose of improving the fluidity of the toner and imparting chargeability. These inorganic fine particles preferably have a particle diameter of 5 to 30 nm, and may be subjected to a hydrophobic treatment with silicone oil or the like. Also,
Inorganic fine particles having a particle diameter of 100 to 200 nm may be mixed as a transfer aid.

The external addition can be performed by, for example, a V-type blender, a Henschel mixer, a Q-type mixer, a Loedige mixer, a cyclomix or the like. At this time, various additives may be added as necessary. Examples of these additives include other known fluidizing agents, cleaning aids and transfer aids such as polystyrene fine particles, polymethyl methacrylate fine particles, and polyvinylidene fluoride fine particles. The ultrasonic vibration sieve used in the present invention preferably has an ultrasonic vibration of a mesh surface of 10 to 50 kHz, more preferably 30 to 40 kHz.
It is preferably z. Moreover, it is preferable that the vibration applied to the net frame is 20 to 2000 Hz. Examples of such an ultrasonic vibrating screen include Ultrasonic (manufactured by Koei Sangyo Co., Ltd.) and Resona Sieve (manufactured by Tokuju Kogyo Co., Ltd.) ultrasonic vibrating screen machines KFS type, KFSR type, KVSH.
Mold (Kowa Kogyosho), sonoscreen (manufactured by Lhasa Industry Co., Ltd.) and the like.

[0047]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, these embodiments do not limit the present invention.

-Externally added toner particles-Binder resin ... 96 parts by weight (terephthalic acid / bisphenol A propylene oxide adduct, Mw = 18500, Tg = 68 ° C)-Phthalocyanine pigment ... 4 parts by weight (CI Pigment Blue 15: 3) After mixing the above-mentioned materials with a Henschel mixer, melt-kneading with an extruder, cooling and crushing, and using a facing-type jet crusher 800AFG (manufactured by Hosokawa Micron Corporation). Fine pulverization was performed, and the fine coarse powder was further classified by an elbow jet classifier to obtain toner particles having an average particle size of 5.5 μm. Silicon oil-treated silica (average particle size: 16 n) was used as an external additive to 100 parts by weight of the obtained toner particles.
m) 1.5 parts by weight, titanium oxide (average particle size: 15 nm)
1.0 kg by weight was charged to a 1000 L Henschel mixer having a capacity of 150 kg per batch, and the jacket was charged at 10 ° C.
Was operated at a flow rate of 10 m ³ / min. Operating conditions were as follows: external addition and mixing were performed at a blade tip peripheral speed of 55 m / s for 40 minutes to obtain externally added toner particles.

-Clogging rate-The clogging rate is 200 m from the center of the sieve mesh 108.
m, the image obtained by photographing three screen surfaces of 300 mm from the center with a digital microscope is analyzed,
The ratio was calculated by taking the ratio of the net opening area before and after sieving and averaging the clogging rates at these three locations.

-Residual rate of weakly adhering component-The sieved product after sieving 30 kg is sampled, and the adhesion strength is expressed in three stages of a weakly adhering component, a medium adhering component and a strongly adhering component,
The residual ratio of silica was evaluated by taking the ratio of each attached component before and after the sieving treatment. The silica adhesion strength was measured by the following method. Weigh 2 g of toner into a 100 ml beaker. Next, 40 ml of a surfactant is added to the beaker, followed by ultrasonic shaking and centrifugation. Then, the precipitate was dried, and a sample not subjected to ultrasonic treatment was subjected to quantitative determination of Si using a fluorescent X-ray analyzer. Then, the distribution of the adhesive strength was measured by changing the intensity of the ultrasonic wave. The measured values were arranged according to the following formula to obtain the adhesion strength. Formula (1) Adhesion strength (desorption Si amount) = ｛1− (Si amount after ultrasonic treatment) /
(Si content before ultrasonic treatment)｝ × 100%. In addition, the adhesion state that peels off by shaking for 5 minutes at an ultrasonic intensity of 50 mA is defined as a weak adhesion component, and the adhesion state that is removed by shaking at 150 mA for 30 minutes is defined as a medium adhesion component. Adhesive components that did not peel were defined as strongly adherent components.

Example 1 In order to sieve the externally added toner particles, the ultrasonic vibrating sieve shown in the first embodiment (see FIGS. 1 and 2) (ultrasonic vibrating sieve [Resona Sieve TMR-7]
0: manufactured by Tokuju Corporation]. As the wiping member 150, a conductive cloth (“Tenabel (manufactured by Teijin Limited)”) wound around the support member 152 (see FIG. 3A) was used. The material of the inner wall of the sieving machine was stainless steel, and the surface was buffed. The sieve mesh 108
Has a mesh size of 45 μm and a wire diameter of 40 μm (300 mesh
Twill weave) stainless steel net was used. The vibration frequency of the ultrasonic wave is 36 KHz, and the oscillation mode of the ultrasonic wave is 10 Hz.
Pulse operation. In addition, the wiping member 150 has four tenabel-fixed aluminum plates having a width of W: 30 mm and a length of 1: 250 mm, each of which is installed in a cross at a position f = 50 mm away from the center of the sieve mesh. , And swirled by the vibration of the mesh surface. The weight phase angle θ _W of the vibration motor was set to 40 degrees. Feed rate 15 from the upper portion of material supply port 118 to be sieved using a screw feeder.
A total of 300 kg of the externally added toner was supplied at 0 kg / h. The clogging ratio after the completion of the operation was 21.0%, and the yield was 96.0%. In addition, we sample sieve fraction,
The residual ratio of the weakly adhered components was evaluated. Table 1 shows the results.

(Example 2) A sieve mesh 108 stretched over the ultrasonic vibrating sieve shown in the first embodiment (see FIGS. 1 and 2)
The operation was performed under the same conditions as in Example 1 except that an AD stainless steel screen (manufactured by Asada Mesh Co., Ltd.) having a mesh size of 46 μm and a wire diameter of 18 μm (400 mesh, plain weave) was used. The clogging ratio after the completion of the operation was 12.0%, and the yield was 97.3%. In addition, the sieve fraction was sampled, and the residual ratio of weakly adhered components was evaluated. Table 1 shows the results.

Example 3 Second Embodiment (FIGS. 5 to 7)
Using ultrasonic vibration sieves indicated by reference), except for using 80 ° the weight phase angle theta _W vibration motor was operated under the conditions of Example 1. The distance L from the center of the screen 108 to the center of the supply port was 280 mm. After removing the coarse powder for 30 minutes, the supply is stopped, and one minute later, suction is performed for 30 seconds by a blower (not shown) connected to a 38 mm-diameter coarse powder outlet 166 15 mm above the net. And a series of these operations was repeated four times.
The suction wind speed by the blower was adjusted to be 12 m / s. The clogging rate after the operation was completed was 10.0%, and the yield was 9
9.9%. In addition, the sieve fraction was sampled, and the residual ratio of weakly adhered components was evaluated. Table 1 shows the results.

Example 4 Second Embodiment (FIGS. 5 to 7)
8), the operation was carried out under the conditions of Example 3 except that two air nozzles 180 shown in FIG. 8 were installed. The air nozzle 180 has an inner diameter of 10 mm and a length of 25
The end of a 0 mm circular tube was closed, and a 0.5 mm slit was inclined in the circumferential direction of the circular tube by 45 degrees with respect to a plane perpendicular to the net plane. In addition, the inclination direction of the air nozzle 180 was a direction along the flow of the material to be sieved formed by the vibration of the vibration motor. The air nozzle 180 was installed at a position 30 mm away from the screen 108 surface. The second air nozzle 180 was installed at a position where the first air nozzle 180 was rotated 180 degrees around the center of the screen 108 surface. Compressed air with a pressure of 0.25 MPa was discharged at a suction timing of 30 seconds in Example 3. The clogging ratio after the completion of the operation was 5.0%, and the yield was 99.8%. In addition, the sieve fraction was sampled, and the residual ratio of weakly adhered components was evaluated. Table 1 shows the results.

Comparative Example 1 The operation was carried out under the same conditions as in Example 1 except that a conventional ultrasonic vibrating sieve shown in FIG. 9 was used. When the mesh surface was photographed with a microscope after the operation for 30 minutes, clogging of about 70% was confirmed. 30 more
As a result of the minute operation, the toner stopped passing through the net due to clogging, and the operation was stopped. Observation of the net surface with a microscope revealed that a large amount of white aggregates adhered to the net surface. The initial 30 minute yield was 98.5%. In addition, the sieve fraction was sampled, and the residual ratio of weakly adhered components was evaluated. The results are shown in Table 1, and the ratio of the weakly adhered components remaining in the sieve sample was as low as 42%.

Comparative Example 2 First Embodiment (FIGS. 1 and 2)
Wiping member 150 in the ultrasonic vibrating screen shown in FIG.
The operation was carried out under the same conditions as in Example 1 except that the brush was adhered to the end of the support 152 instead of. Four brushes were used in which a nylon wire having a diameter of 0.3 mm and a length of 20 mm was planted on a nylon resin plate having a width W of 30 mm and a length l of 250 mm. The four brushes were each installed in a cross at a position f = 50 mm away from the center of the sieve mesh, and swirled by the vibration of the mesh surface. Clogging rate after operation is 3
8.0% and the yield was 97.0%. In addition, the sieve fraction was sampled, and the residual ratio of weakly adhered components was evaluated. The results are shown in Table 1. The residual ratio of the weakly adhered components of the sieve sample was 84%.
% Was slightly lower.

[0057]

[Table 1]

According to the examples, the ultrasonic vibrating sieve of the present invention adopts the above-described structure, thereby eliminating the dust collection loss inherent in the ultrasonic vibrating sieve and preventing the material from being damaged. It can be seen that high throughput can be continuously and stably secured even when sieving a material that is likely to be clogged while maintaining the same. Further, it can be seen that by using the toner in the toner production process, it is possible to obtain a high-quality toner having substantially no particles having a specified particle size or more that adversely affect image quality while securing high productivity and high yield.

[0059]

As described above, according to the present invention, an ultrasonic vibrating sieve which can be sieved stably for a long period of time without causing clogging even when a specific material which is liable to clogging is used, and an electronic device using the same. A method for producing a photographic toner can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of an ultrasonic vibration sieve of the present invention. It is a side view schematic block diagram.

FIG. 2 is a schematic configuration diagram on a sieve net showing a first embodiment of an ultrasonic vibration sieve of the present invention. It is an upper surface schematic block diagram.

FIG. 3 is a schematic view showing a specific example of a wiping member in the ultrasonic vibration sieve of the present invention.

FIG. 4 is a conceptual diagram showing removal of deposits and clogging by a material to be sieved on a sieve mesh surface by a wiping member in the ultrasonic vibration sieve of the present invention.

FIG. 5 is a schematic configuration diagram showing a second embodiment of the ultrasonic vibration sieve of the present invention.

FIG. 6 is a schematic configuration diagram on a sieve net showing a second embodiment of the ultrasonic vibration sieve of the present invention.

FIG. 7 is a schematic configuration diagram showing the vicinity of a wiping member according to a second embodiment of the ultrasonic vibration sieve of the present invention.

FIG. 8 is a schematic configuration diagram showing another example of the vicinity of the wiping member in the second embodiment of the ultrasonic vibration sieve of the present invention.

FIG. 9 is an explanatory view of a main part of a vibration motor suitably used for the ultrasonic vibration sieve of the present invention.

FIG. 10 is an explanatory diagram showing a phase angle in a vibration motor suitably used for the ultrasonic vibration sieve of the present invention.

FIG. 11 is a conceptual diagram showing a behavior of a material to be sieved in the second embodiment of the ultrasonic vibration sieve of the present invention.

FIG. 12 is a conceptual diagram of a general ultrasonic vibration sieve. FIG.

[Explanation of symbols]

100 base frame, 102 coil spring, 104 sieve frame, 105 upper frame, 106 bottom, 108 sieve mesh, 108 sieve mesh, 110 support frame, 112 Resonance ring, 114 ultrasonic transducer,
116 ··· sieve product collection port, 118 · · · material to be sieved, 120 · · coarse powder outlet, 122 · · · top lid 130 · · ·
Vibration motor, 150 wiping member, 152 support material, 156 dispersion cone, 158 deposits and clogging, 160 upper frame, 162 upper lid, 164 sieve material supply port 166, coarse powder discharge port, 168, automatic valve 170, support ring, 172, upper fixing ring, 174, lower fixing ring 176, spring, 178
..Buffer plate, 180..air nozzle d. Net wire diameter (μ
m), A.I. Mesh opening (μm); Width of the wiping member (mm), l. Length of wipe member (mm), f: distance (mm) from wipe member to center of net, Distance (mm) from the center of the net to the center of the supply port, θw. Weight phase angle (°)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B07B 1/52 B07B 1/52 Z 1/55 1/55 G03G 9/087 G03G 9/08 381 (72) Inventor Tsuyoshi Tanabe 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Jun Sugitate 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Koichi Sugiyama Takematsu, Minami Ashigara City, Kanagawa Prefecture 1600 Fuji Xerox Co., Ltd. (72) Inventor Takuhiro Mizuguchi 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Fuji Xerox Co., Ltd. (72) Inventor Hitomi Nakamura 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture F Xerox Co., Ltd. Terms (reference) 2H005 AB03 4D021 AA01 AB02 AC01 AC02 AC10 CA07 CB09 CB11 DA03 DB11 DB12 DB16 EA09 EA10

Claims (2)

[Claims] 1. An ultrasonic vibrating sieve that applies vibration from a vibrating motor and micro-vibration by ultrasonic waves to a mesh surface to separate the material to be sieved into fine powder and coarse powder. An ultrasonic vibration sieve comprising a wiping member arranged and wiping a material to be sieved remaining on a mesh surface. 2. A method for producing an electrophotographic toner, wherein the ultrasonic vibration sieve according to claim 1 is used in a sieving step in a toner production step.