JP2001255702A - Method and device for manufacturing electrophotographic toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing electrophotographic toner such that when the classified fine powder which is conventionally discarded is granulated to be used as recycled, the bulk density of the mixture of at least a binder resin, a coloring agent, an electrification controlling agent and the granulated product is increased so as to increase the limit process amount in a kneading and extruding device and that discarding of the classified fine powder can be avoided, and to provide a device for the manufacture of the toner, to supply the granulated product to the device, to provide a method of manufacturing electrophotographic toner by which the limit process amount in the kneading and extruding device is improved and all of the powder can be used for recycling without discarding the classified fine powder, to provide a device for the manufacture, and to provide the granulated product and a processing material for the method. SOLUTION: In the method of manufacturing toner including processes of mixing, kneading and pulverizing and classifying a composition consisting of at least a binder resin, coloring agent, electrification controlling agent and regenerated fine powder, the classified fine powder produced in the pulverizing and classifying process is granulated into particles having 0.45 g/cc to 0.80 g/cc bulk density and the granulated product is reused.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a toner by melt-kneading, pulverizing, and classifying a composition comprising at least a binder resin, a colorant, a charge control agent, and a classified fine powder to be recycled.

[0002]

2. Description of the Related Art A method of producing an electrophotographic toner by mixing at least a binder resin, a colorant, and a charge control agent, and melt-kneading, pulverizing, and classifying the toner is a technique that has been employed for a long time. On the other hand, toner fine powder generated in the classification process (hereinafter, referred to as
The term “classified fine powder” in the present specification) is to be removed from the toner to be a product. However, discarding the classified fine powder lowers the total yield of the toner raw material and increases the cost of the raw material, and there is also a concern about an adverse effect on the environment such as an increase in the amount of waste.

[0003] In order to solve this problem, classified fine powder has been recovered and used as a part of raw materials. However, when the classified fine powder itself is used as a raw material, it is a fine powder, and thus has poor fluidity, and the mixing property with the basic raw material resin or colorant is reduced.
In some cases, the bulk density of the mixture with the charge control agent became too small, and the supply to the kneading and extruding apparatus became unstable. As a result, there is a disadvantage that the toner quality is deteriorated due to uneven distribution of the colorant. For this purpose, Japanese Patent Application Laid-Open No. 6-266157
As disclosed in Japanese Patent Application Laid-Open Publication No. 9-127732 and the like, it has been proposed to granulate and use the raw fine powder obtained by classification. However, depending on the type ratio of raw materials, etc., even when granulated products are added, the amount of classified fine powder discharged by the process is extremely large, and the limit processing amount is lower than the amount of classified fine powder. Will occur. Further, when granulating the classified fine powder discharged from each device, particularly a classifying device (for example, a bag filter or a cyclone), the bulk density of the discharged classified fine powder varies, and the bulk density / granule of the granulated product varies. A large variation occurs in the diameter / granulation processing speed (capacity), and as a result, the limit processing amount in the melt-kneading section is limited.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and when the above-mentioned conventionally discarded classified fine powder is granulated and used for recycling, at least a binder resin and a coloring agent are used. Of electrophotographic toner that can increase the bulk density of a mixture of an agent, a charge control agent, and a granulated product (granulated product), increase the limit processing amount in a kneading extruder, and eliminate the disposal of classified fine powder. It is an object of the present invention to provide a method, a manufacturing apparatus and a granulated product. In other words, an object of the present invention is to improve the limit processing amount in a kneading and extruding apparatus, without discarding the classified fine powder, a method for manufacturing a recyclable electrophotographic toner, a manufacturing apparatus and a granulated product therefor, It is to provide a processing material.

[0005]

According to a first aspect of the present invention, a composition comprising at least a binder resin, a colorant, a charge controlling agent and regenerated fine powder is mixed, kneaded, crushed and classified. In the toner production method, the fine powder produced by the pulverization / classification has a bulk density of 0.45 g / cc to 0.80 g / cc.
The present invention provides a method for producing an electrophotographic toner, characterized by reusing granulated particles. According to a second aspect, there is provided a method for producing an electrophotographic toner, wherein fine powder generated by pulverization and classification is collectively collected from a process. According to a third aspect, the bulk density of the classified fine powder collected in the collecting step is 0.05 g / cc.
To 0.40 g / cc, and a method for producing an electrophotographic toner. According to a fourth perspective,
A method for producing an electrophotographic toner, further comprising a granulating step of granulating for reusing the classified fine powder collected collectively. According to the fifth aspect, between the collection step and the granulation step, a supply step of supplying the collectively collected classified fine powder to the granulation step is provided, and the supply step includes:
The present invention provides a method for producing an electrophotographic toner, wherein the method is performed by a discharging unit having rotating blades. Sixth
According to the aspect of the present invention, the storage means for storing the classified fine powder collectively collected after the collecting step is provided, and the supply step of the classified fine powder to the granulation step involves the supply of the classified fine powder from the storage means. The present invention provides a method for producing an electrophotographic toner. According to a seventh aspect, in the supply step of the classified fine powder, the compression occurs together with the supply of the classified fine powder, so that the bulk density of the granulated product of the classified fine powder is 0.05 g / cc or more.
0.40 g / cc to bulk density 0.45 g / cc to 0.8
A method for producing an electrophotographic toner is provided, wherein the increase to 0 g / cc is assisted. According to an eighth aspect, there is provided a method for producing an electrophotographic toner, wherein granulation in a granulation step is performed by compression and solidification between a plurality of rollers. According to a ninth aspect, when the plurality of rollers have pressure adjusting means, the bulk density of the classified fine powder granules is from 0.05 g / cc to 0.40 g / cc to a bulk density of 0.4 g / cc to 0.4 g / cc.
A method for producing an electrophotographic toner is provided, wherein the increase from 5 g / cc to 0.80 g / cc is assisted. According to a tenth aspect, there is provided a method of manufacturing an electrophotographic toner, wherein the plurality of rollers have a temperature adjusting unit. According to an eleventh aspect, there is provided a method for producing an electrophotographic toner, further comprising a coarse pulverizing step of coarsely pulverizing a granulated product of the classified fine powder after the granulating step. According to a twelfth aspect, in the coarse pulverizing step, the granulated material is coarsely pulverized to an average particle size of 30 μm to 5000 μm, thereby obtaining a bulk density of the classified fine powder of 0.0
5 g / cc to 0.40 g / cc to bulk density of 0.45 g / cc
A method for producing an electrophotographic toner is provided, wherein the increase in density from cc to 0.80 g / cc is complemented.

According to the thirteenth to twenty-fourth aspects of the present invention, there are provided electrophotographic toner manufacturing apparatuses each suitable for carrying out the electrophotographic toner manufacturing method,
Further, according to the twenty-fifth and twenty-sixth aspects of the present invention, there are provided a granulated product of a classified fine powder suitable for producing the electrophotographic toner according to the present invention, and a raw material for the granulated product.

Hereinafter, the present invention will be described in detail. As described above, one of the aspects of the present invention is a method for producing a toner by melt-kneading, pulverizing, and classifying a mixture comprising at least a binder resin, a colorant, a charge control agent, and regenerated fine powder. Fine powder with bulk density of 0.45g / cc ~
This is a method of recycling granulated material to 0.80 g / cc.

[0008] Thus, the bulk density of 0.45 g / cc to 0.1 g / cc.
The classified fine powder granulated to 80 g / cc is mixed with a binder resin, a colorant, a charge control agent, and the like as a part of the raw material, and supplied to a kneading and extruding device, whereby the classified fine powder granulated to have a bulk density of the mixture is obtained. Can be maintained as if not added,
The limit processing amount of classified fine powder is improved, and all of the classified fine powder can be recycled.

Further, it is desirable that the bulk density of the granulated product of the classified fine powder is preferably 0.50 g / cc to 0.65 g / cc. In addition, the classified fine powder is collectively collected by connecting pipes and the like from the lower part of each device in a process in which the fine powder is discharged, and is supplied to a granulator for compression and solidification by a discharge device having rotating blades, thereby stably forming the fine powder. Granulated.

The classified fine powder used in the present invention preferably does not contain 50% or more of particles having a particle size of 4 μm or more, and more preferably does not contain 10% or more of particles having a particle size of 2 μm or more. Things. These usually have a bulk density of 0.05 g / cc to 0.40 g / cc.

In the present invention, such classified fine powder is
It is granulated into granules having the above bulk density. This granulation is assisted by involving a controlled compression in the feed step to the granulation step and / or by involving roll compression at a controlled pressure in the granulation step. Furthermore, the bulk density also depends on the degree of voids between the granulated particles, and the degree of voids also depends on the degree of cutting and crushing of the granulated material, that is, the average particle size of the granulated material. Although the porosity increases, in the present invention, after the granulation step, a coarse pulverization step of coarsely pulverizing the granulated material of the classified fine powder is further provided. It is preferably achieved by coarsely pulverizing to a size of 30 μm to 5000 μm.

[0012]

FIG. 1 shows an example of a toner production flow and a production apparatus according to the present invention. The “mixing step” and “mixing means” in the present invention are shown as “mixing part” in this example for ease of explanation, and similarly, the “kneading step” and “kneading means” are also shown as “kneading part”. It is. The same applies to the case of a pulverizing section, a classifying section and the like. In the production shown in FIG. 1, at least the raw materials of the binder resin, the colorant, the charge control agent, and the regenerated fine powder (granulated product) measured in the raw material measuring section (A) are kneaded by air transport. )
Mixing, melt kneading and cooling are performed.

The kneaded material discharged from the kneading section (B) is further sent to the pulverizing and classifying section (C) by pneumatic transportation, and is adjusted to a predetermined particle size by the pulverizer (6) and the classifier (7). . A toner having a predetermined particle size or less is classified as fine powder in the present invention.
Collected in bag filter (1) and cyclone (2). The classified fine powder collected by the bag filter (1) and the cyclone (2) is pneumatically transported to the classified fine powder collecting bag filter (4) through the collecting pipe (3) of the collecting section (E), where the classified fine powder is collectively collected. Collected. In the present invention, the bulk density of the classified fine powder collectively collected in this collection step is usually 0.1.
05 g / cc to 0.40 g / cc. Thereafter, the classified fine powder is discharged from the classified fine powder collecting bag filter (4) to the granulator (5), and the classified fine powder is granulated to a desired bulk density. The granulated product discharged from the granulator is sent to the raw material measuring section (A) by pneumatic transportation.

FIG. 2 shows a granulator (5) as an example of a granulating means in the present invention for compressing and solidifying the classified fine powder. In this example, the classified fine powder from the hopper (8) storing the classified fine powder is transported to the roll part (10) by a screw (9) or an auger (9) that transports the classified fine powder, where the classified fine powder is compression-rolled. Is done. The surface of the roll may be processed so that the releasability is improved. This roll is maintained at a constant roll pressure by a hydraulic cylinder (14). The rolled plate-like material is coarsely crushed by a crusher (11) and crushed by a finer (12), and the obtained fine particles are further crushed by a sizing machine (13). Although not shown, the granulator (5) includes a roll (10).
Roll temperature control mechanism is provided.

In the above construction, the classified fine powder stored in the hopper (8) is sent to the roll (10) by the screw (9) or the auger. In this case, the compression ratio of the fine powder is higher when the auger is used than when the screw is used. One of the rolls is fixed to the center shaft, and the other is pressed at a constant pressure in the horizontal direction by a hydraulic cylinder (14) whose pressure can be adjusted. The fine powder sent to the roll is
By being compressed between the two rolls, it is rolled into a plate shape and sent downward. The sample hardened into a plate shape is crushed by a crusher (11) into pieces each having a size of several mm to several cm. The fragments are further pulverized by a finer (12) or, if necessary, a sizer (13).

In the present invention, of course, the hopper (8) can be used as a storage means for storing the classified fine powder collected collectively. In this case, the hopper (8) is separated from the granulator (5). For example, the supply of the classified fine powder to the granulator (5) can be adjusted by providing it in the middle of a transport path arranged between the classified fine powder collection bag filter (4) and the granulator (5). . However, it is preferable to provide a storage means for storing the classified fine powder collected collectively, separately from the hopper (8).

FIG. 3 shows a discharging device (lower part of a collecting bag filter) as an example of a supplying means for supplying the classified fine powder to the granulator.
Is shown. In the drawing, reference numeral (15) denotes a casing, (16) denotes a motor for driving a stirring blade, and (17) denotes a stirring blade.
In this configuration, the classified fine powder collected in the casing (15) is discharged to the granulator by the stirring blade (17) driven by the motor (16).

[0018]

[Comparative Examples 1-4 and Examples 1-3]

 Phthalocyanine green water-containing cake (solid content 30%) 200 parts Carbon black (MA60 manufactured by Mitsubishi Chemical Corporation) 540 parts Polyester resin (acid value; 3, hydroxyl value; 25, Mn; 45000, Mw / Mn; 4.0. Tg; (60 ° C.) 1200 parts were kneaded at 160 ° C. for a sufficient time, then pulverized and classified.

[0019]

[Table 1] * Limit processing amount indicates the actual amount of granulated product used. The present invention can of course be applied to not only monochrome toners but also color toners.

[0020]

As is apparent from the detailed and specific description above, according to the present invention, the classified fine powder which has conventionally been reduced in the amount of waste by increasing the limit processing amount in the kneading and extruding apparatus is granulated. By improving the method, everything can be made recyclable. That is, there is an excellent effect that the limit processing amount in the kneading and extruding device can exceed the generation amount of the classified fine powder.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a toner manufacturing apparatus and a manufacturing method of the present invention.

FIG. 2 is a configuration diagram of an example of a granulator for compression and solidification according to the present invention.

FIG. 3 is a discharge device for discharging classified fine powder to the granulator of the present invention.
It is a lineblock diagram showing an example of (recovery bag filter lower part).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bag filter 2 Cyclone 3 Collection pipe 4 Collection bag filter 5 Granulator 6 Crusher 7 Classifier 8 Hopper 9 Screw 10 Roll part 11 Crusher 12 Crusher 13 Granulator 14 Hydraulic cylinder 15 Casing 16 Motor 17 Stirring blade A Raw material measuring section B Kneading section C Pulverizing / classifying section D External additive mixing section E Granulating section

Claims (26)

[Claims] 1. A toner production method comprising the steps of mixing, kneading, pulverizing and classifying at least a composition comprising at least a binder resin, a colorant, a charge control agent and a regenerated fine powder.
The classified fine powder generated in the pulverizing / classifying process has a bulk density of 0.45 g.
/ G / cc to 0.80 g / cc, and the granulated product is reused. 2. The method for producing an electrophotographic toner according to claim 1, further comprising a collecting step of collectively collecting the classified fine powder generated in the pulverizing step and / or the classifying step from the classifying step. 3. The production of an electrophotographic toner according to claim 2, wherein the bulk density of the classified fine powder collectively collected in the collection step is 0.05 g / cc to 0.40 g / cc. Method. 4. The method for producing a toner for electrophotography according to claim 2, further comprising a granulating step of granulating the classified fine powder collected collectively for reuse. 5. A supply step is provided between the collection step and the granulation step to supply the collectively collected classified fine powder to the granulation step, and the supply step is performed by a discharge means having rotating blades. 5. The method for producing an electrophotographic toner according to claim 4, wherein: 6. A storage means for storing the classified fine powder collectively collected after the collecting step, wherein the step of supplying the classified fine powder to the granulating step involves supplying the classified fine powder from the storing means. The method for producing an electrophotographic toner according to any one of claims 1 to 5, wherein: 7. The step of supplying the classified fine powder causes compression together with the supply of the classified fine powder, so that the bulk density of the granulated material of the classified fine powder is from 0.05 g / cc to 0.40 g / cc to 0.45 g. The method for producing an electrophotographic toner according to claim 6, wherein an increase from / cc to 0.80 g / cc is assisted. 8. The method for producing an electrophotographic toner according to claim 1, wherein the granulation in the granulating step is performed by compression and solidification between a plurality of rollers. 9. The bulk density of the classified fine powder granules of 0.05 g, wherein the plurality of rollers have pressure adjusting means.
/ Cc-0.40 g / cc to bulk density 0.45 g / cc
9. The method for producing an electrophotographic toner according to claim 8, wherein an increase to 0.80 g / cc is assisted. 10. The method for producing an electrophotographic toner according to claim 8, wherein the plurality of rollers have a temperature adjusting unit. 11. The electrophotographic toner according to claim 1, further comprising, after the granulating step, a coarse pulverizing step of coarsely pulverizing the granulated material of the classified fine powder. Manufacturing method. 12. The coarse pulverizing step comprises coarsely pulverizing the granulated product to an average particle size of 30 μm to 5000 μm,
Bulk density of granulated classified fine powder 0.05 g / cc to 0.40
g / cc to bulk density 0.45 g / cc to 0.80 g / c
2. The increase in density to c is complemented.
2. The method for producing an electrophotographic toner according to item 1. 13. A toner production apparatus having a mixing means for mixing a composition comprising at least a binder resin, a colorant, a charge controlling agent and regenerated fine powder, a kneading means for kneading the mixture, and a means for pulverizing and classifying the kneaded product. In the above, the classified fine powder produced by the pulverizing / classifying means has a bulk density of 0.45 g / cc or more.
An apparatus for producing an electrophotographic toner, wherein the granulated product is granulated to 0.80 g / cc and the granulated product is reused. 14. The apparatus for producing an electrophotographic toner according to claim 13, further comprising a collecting means for collectively collecting the classified fine powder generated by the pulverizing means and / or the classifying means from the classifying means. 15. The bulk density of the classified fine powder collectively collected by the collecting means is 0.05 g / cc to 0.40 g / c.
The apparatus for producing an electrophotographic toner according to claim 15, wherein c. 16. The apparatus for producing an electrophotographic toner according to claim 14, further comprising a granulating means for granulating the collectively collected classified fine powder for reuse. 17. A supply means for supplying the collectively collected classified fine powder to the granulation means is provided between the collection means and the granulation means, and the supply means is a discharge means having rotating blades. The apparatus for producing an electrophotographic toner according to claim 16, wherein: 18. A storage means for storing the classified fine powder collectively collected after the collecting means, and the supply of the classified fine powder to the granulating means involves the supply of the classified fine powder from the storage means. 18. The apparatus for producing an electrophotographic toner according to claim 13, wherein: 19. The classified fine powder supply means generates a compression together with the supply of the classified fine powder, so that the bulk density of the granulated material of the classified fine powder is from 0.05 g / cc to 0.40 g / cc to a bulk density of 0.45 g. 20. The apparatus for producing an electrophotographic toner according to claim 18, wherein an increase from / cc to 0.80 g / cc is assisted. 20. The granulating means is a plurality of rollers,
The granulation is performed by compression and solidification between the rollers,
An apparatus for producing an electrophotographic toner according to claim 13. 21. The method according to claim 21, wherein the plurality of rollers have pressure adjusting means, so that the bulk density of the granulated classified fine powder is 0.05.
g / cc to 0.40 g / cc to bulk density 0.45 g / c
21. The apparatus for producing an electrophotographic toner according to claim 20, wherein an increase of c to 0.80 g / cc is assisted. 22. The apparatus for producing an electrophotographic toner according to claim 20, wherein the plurality of rollers have a temperature adjusting unit. 23. The electrophotographic toner according to claim 13, further comprising, after the granulating means, a coarse pulverizing means for coarsely pulverizing the granulated material of the classified fine powder. Manufacturing equipment. 24. The coarse crushing means coarsely crushes the granulated material to an average particle size of 30 μm to 5000 μm, whereby the bulk density of the classified fine powder granules is 0.05 g / cc to 0.1 μm.
40 g / cc to bulk density 0.45 g / cc to 0.80 g
24. The apparatus for producing an electrophotographic toner according to claim 23, wherein an increase in density to / cc is complemented. 25. A composition comprising at least a binder resin, a colorant, a charge control agent and a regenerated fine powder, are mixed and kneaded,
A granulated product of the classified fine powder generated in the pulverizing step / classifying step in the production of the toner having the respective steps of pulverizing / classifying,
Classification for electrophotographic toner to be reused in toner production, characterized by having an average particle size of 30 μm to 5000 μm and a bulk density of 0.45 g / cc to 0.80 g / cc. Granules of fine powder. 26. A composition comprising at least a binder resin, a colorant, a charge controlling agent and a regenerated fine powder, are mixed and kneaded,
Classified fine powder produced in the pulverizing step / classifying step in the production of toner having the respective steps of pulverizing / classifying, and having a particle size of
Classification for an electrophotographic toner to be reused in the production of a toner, characterized by not containing 50% or more of particles having a size of at least 50 μm and having a bulk density of 0.05 g / cc to 0.40 g / cc. Raw material for fine powder granules.