JP2663036B2 - Method for pulverizing resin composition and method for producing toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is used for a method for efficiently and stably pulverizing a resin composition, and for electrophotography, electrostatic printing, magnetic recording, and the like. The present invention relates to a toner manufacturing method for efficiently manufacturing a toner with a sharp particle size distribution.

[Prior Art] Conventionally, as a method for producing a dry toner, a pulverization method, a polymerization method, an encapsulation method and the like are known, but a more general method is a pulverization method. As a general manufacturing method of the pulverization method, first, after mixing the raw materials such as binder resin, pigment and the like, melt kneading,
After cooling, this is coarsely pulverized to obtain a coarsely pulverized product, which is then finely pulverized into fine particles. This is classified as required, and the toner is used after the particle diameters are made uniform. Various external additives may be added to the toner as needed.

In such a pulverization, as a pulverizing device to be used, a pulverizer using media such as a ball mill, a sand mill and an attritor, a mechanical pulverizer such as a hammer mill, a pin mill, and a turbo mill, a jet such as an I mill, a counter jet, and a supermicron mill Various other pulverizers such as a pulverizer are known.

Generally, in order to pulverize a resin composition to a micron order, a mechanical pulverizer or a jet pulverizer is often used. In particular, a jet mill is an effective device for obtaining fine particles, and is widely used. When a toner used in a copying machine, a printer, or the like is manufactured, a jet mill is widely used for the fine particles.

Further, a pulverizer is usually used in combination with a classifier to make the pulverized particle size uniform. FIG. 7 is a flowchart showing the method. FIG. 8 is a flowchart showing an example in which two classifiers are combined with one crusher. JP-A-63-112626 discloses a toner pulverizing method using a plurality of pulverizers and classifiers in combination, and its flowchart is shown in FIG. This method is a system designed to increase the efficiency of grinding.

However, in recent years, binder resins used for toners have become even lower in softening point, lower Tg, and lower melting point.
When the resin composition having such properties is further pulverized, if the pulverization method as shown in FIG. 8 or FIG. (2) Fusing occurs in the apparatus used for the pulverizing means and the second classifying means, which causes a reduction in production efficiency. Further, under such irregular production, the toner performance is usually not stable and uniform toner cannot be obtained, and these adverse effects also appear in image quality and the like.

Generally, many different properties are required for a toner, and in order to obtain the required properties, it often depends on not only the raw materials used but also the manufacturing method.

In the pulverization step, it is required that the pulverized particles are uniform and have a sharp particle size distribution. It is also desirable to efficiently and stably produce high quality toner at low cost.

As described above, a binder resin generally used for a toner is soft or has a low melting point, a low softening point, and a low Tg, and a toner composition or a resin composition using such a resin is used. When the material is subjected to the fine pulverization process, problems due to the properties of the resin, that is, adhesion or fusing to the inside of the apparatus main body are liable to occur, and in particular, in recent years, the performance required for the toner has become more severe. I have. For example, as an energy-saving measure of a copying machine, a soft binder such as wax is used as a binder resin to fix an image on a recording material by pressure, or a fixing speed is increased even in the case of heating type fixing. In order to reduce power consumption for fixing and to fix at a low temperature, a binder resin having a low Tg or a low softening point has been used.

Further, in order to improve image quality in copiers and printers, the toner particle diameter has been gradually shifted to finer directions. In general, as the material becomes finer, the interparticle force becomes greater. However, the same applies to resin and toner. When an external force such as an impact force or a frictional force acts on such a cohesive state, toners and particles further fuse to the main assembly.

Therefore, the occurrence of fusion in the main body as described above is increasing. When such a phenomenon occurs, the operation time of the apparatus is reduced, and not only does the cost of toner production increase, but also the pulverized material having stable performance cannot be obtained because the apparatus is not always operated in a stable state. I will. That is, it is not possible to supply toner having uniform performance. Further, in order to suppress the occurrence of fusion, it is necessary to use the pulverizer while suppressing its capacity. This also causes a cost increase.

As a method for preventing such a fusion phenomenon, a method of attaching a cooling jacket to a pulverizer and a so-called freeze pulverization method using dry ice or liquid nitrogen are well known. Such a method is sometimes and sometimes effective. However, there is a problem in applying this method to toner. That is, the method of attaching the cooling jacket has a problem of dew condensation of water. Toners, which are used in electrophotography, dislike excessive moisture. Therefore,
Condensation is not preferred. In addition, since freeze-pulverization is expensive and requires airtightness, it is not suitable for a system using a jet mill, a wind classifier, or the like that takes in a large amount of outside air. Therefore, such a method is not suitable for producing a toner.

Furthermore, using a fluoride coating, a polyethylene, silicon product, or a fluorine product in a place where fusion is likely to occur, or using the product by itself is not a durable or crushing machine. There is a problem with abrasion resistance and it is not a permanent measure.

In this way, a method for stably and efficiently pulverizing resin fine powder, a toner having high quality performance can be efficiently and stably
Further, a method of manufacturing at low cost is desired.

[Problems to be Solved by the Invention] In view of the above prior art, an object of the present invention is to provide a resin composition that does not generate fusion or the like and that can be stably produced without generating dust in the apparatus body. The present invention further provides a pulverization method capable of obtaining a finely pulverized resin composition at a low cost without lowering production efficiency.

Further, it is intended to provide a method for producing a toner in which a fine powder toner can be stably obtained by eliminating generation of a fused material,
Another object of the present invention is to provide a method for producing a toner that always provides a constant and uniform toner, and a method for producing a toner having a finer particle diameter at low cost without lowering production efficiency.

[Means and Actions for Solving the Problems] The features of the present invention are as follows. First, in a method for pulverizing a resin composition comprising a resin alone or a resin and one or more additives, the resin composition Is introduced into a first classifying means to classify the first coarse powder into a first coarse powder and a first classified powder.
Pulverized by introducing into a pulverizing means, the pulverized product of the obtained first coarse powder is introduced into the first classifying means together with the raw material coarse particles and classified,
The classified first classified powder is introduced into the second classifying means together with the raw material coarse particles to classify into the second coarse powder and the second classified powder, and the classified second coarse powder is introduced into the second pulverizing means. The method is a method for pulverizing a resin composition in which a pulverized product of a second coarse powder obtained by pulverization is introduced into a second classification means.

Secondly, in a method for producing toner particles, a composition containing at least a binder resin and a colorant is melt-kneaded, then cooled and solidified, and the solidified product is pulverized by a pulverizing means and then classified to produce toner particles. After coarsely crushing the material and making it into a coarsely crushed product,
The crushed material is introduced into the first classifying means to classify the first coarse powder and the first classified powder, and the classified first coarse powder is introduced into the first crushing means and pulverized. The crushed material of the coarse powder is introduced into the first classifying means together with the crushed material and classified, and the classified first classified powder is introduced into the second classifying means together with the crushed material to form the second coarse powder and the second classified powder. The classified and classified second coarse powder is introduced into a second pulverizing means to be pulverized, and the obtained pulverized second coarse powder is introduced into the second classifying means to obtain the second classified powder as a finely divided product. The method for producing a toner.

Further, a method of pulverizing the resin composition in which the ratio of the capacity of the first pulverizing means and the first classifying means to the capacity of the second pulverizing means and the second classifying means is 1: 1 to 1: 0.3 is preferable. The toner production method described above, wherein the ratio of the capacity of the pulverizing means and the first classifying means to the capacity of the second pulverizing means and the second classifying means is 1: 1 to 1: 0.3 is preferable.

Further, a pulverization method of the resin composition in which the input ratio of the raw material coarse particles to the first classification means and the second classification means is 1000: 1 to 2: 1 is preferable. The toner production method in which the input ratio of the raw material coarse particles to the classification means is 1000: 1 to 2: 1 is preferable.

In other words, according to the study of the present inventors, fusion differs rapidly depending on the type of resin, but generally, the lower the softening point of the resin, and the smaller the particle size of the same resin, the faster the fusion occurs. It was noted that it became easier. FIG. 1 shows an example showing the relationship between the finely pulverized particle size and the state of occurrence of fusion. The pulverized raw material was a simple polyester resin having a softening point of about 110 ° C., and the pulverization was performed at room temperature. The pulverizer used was an I-5 model connected to a Micron Separator MS-1 model.
Of course, in the resin composition, the easiness of fusion varies depending on the resin and additives to be blended, but the tendency does not change.

In view of these points, as a result of repeated studies by the present inventors,
The inventors have found a method for pulverizing the resin composition of the present invention and a method for producing a toner.

Hereinafter, the configuration and operation of the present invention will be described in detail.

FIG. 2 shows an example of a flowchart outlining the method of the present invention. The flow of the powder will be described with reference to FIG. Most of the supplied pulverized raw material is sent to the first classifying means together with the pulverized material pulverized by the first pulverizing means, where the pulverized raw material is classified and divided into a first classified coarse powder and a first classified fine powder.
The classified coarse powder is sent to the first grinding means. The first classified fine powder is sent to the second classifying means together with a part of the pulverized material and the pulverized raw material pulverized by the second pulverizing means, where the pulverized material is classified.
It is divided into classified coarse powder and second classified fine powder, and the second classified coarse powder is sent to the second grinding means. The second classified fine powder is collected as a finely pulverized product or sent to the next step.

In order to carry out the above-mentioned method, it is general that a single device such as a crusher and a classifier is connected by means such as a pipe and used as an integrated device system. FIG. 3 shows a preferred example of such an apparatus system. The integrated device system shown in FIG. 3 includes a raw material supply device 1, a first classifier 7, a first crusher 8, a first classifier cyclone 10, a transportation injection feeder 11, a second classifier 13, and a second crusher 17. , A second classifying cyclone 15, which is mainly connected with a pipe or the like. In this apparatus, the pulverized raw material is supplied from raw material input ports 4 and 5. At this time, in the discharge units 2 and 3 of the raw material supply device 1, the discharged raw material is adjusted to an arbitrary amount and ratio. The pulverized raw material supplied from the raw material input port 5 is introduced into a first classifier 7 through a pipe 6, and the classified first coarse powder is introduced into a first pulverizer 8 through a short pipe 19, and is again supplied to a pipe 6. And is introduced into the first classifier 7. On this occasion,
At the junction indicated by A, the pulverized raw material and the pulverized powder from the first pulverizer are combined and mixed and introduced into the first classifier. The first classified fine powder classified by the first classifier is collected by the collection cyclone 10 through the pipe 9, taken out of the cyclone by the injection feeder 11, and introduced into the second classifier 13 through the pipe 12. The second coarse powder classified by the second classifier 13 is introduced into the second pulverizer 17 through the short pipe 20, is pulverized, passes through the pipe 18 again through the pipe 12, and is introduced into the second classifier. You. At this time, the first classified fine powder is joined at the junction indicated by C, and further, a part of the pulverized raw material introduced into the raw material inlet 4 at the junction indicated by B and guided by the pipe 21 is merged and mixed. Introduced to the 2 classifier. In this example, part B is located on the downstream side in the direction of powder flow from part C, but part C is located on the downstream side of part B. May be provided on the injection feeder side. The second classified fine powder classified by the second classifier passes through the pipe 14 and is collected by the collecting cyclone 15 to be collected as finely pulverized product 16.

Here, each of the crushers 8 and 17 is preferably a device capable of crushing to the target particle size by itself, such as a mechanical crusher such as an MVM crusher manufactured by Hosokawa Micron Corporation, a turbo mill manufactured by Turbo Kogyo Co., Ltd., or an I-type manufactured by NPK Corporation. A pulverizer using a jet stream such as a mill or a micro jet manufactured by Hosokawa Micron Corporation can be used. As the classifiers 7 and 13, a DS separator from NPK, an MS separator from Hosokawa Micron, and other classifiers can be used. Compared with the conventional system shown in FIG. 7, in the system shown in FIG. 2, the processing capacity can be greatly increased only by adding a pulverizer having a small weight in terms of investment. For example, in the pulverization of toner, by adding a pulverizer of 1/2 scale, a pulverization particle size of about 11 to 12 μm is reduced to 75% to 15%.
In the case of a pulverized particle size of about 7% to about 8%,
About 400% capacity improvement was recognized. This results in a significant reduction in investment and energy costs.

In addition, when the conventional system shown in FIG. 9 is used to continue pulverization for a long time, a fusion phenomenon occurs particularly in the second pulverizer, the second classifier, and the piping around the same. In many cases, continuous operation cannot be continued. In particular, as described above, the tendency becomes remarkable as the softening point and Tg of the resin progress. Further, when the finely pulverized particle diameter is further advanced, fusion occurs at an accelerated rate.

However, in the present invention, the fusion phenomenon under such a situation, without using a complicated apparatus, and even without using a costly method such as freezing and pulverization, simply,
This can be prevented with a small investment, the resin composition that can be stably produced can be pulverized, and a high-quality homogeneous toner can always be obtained.

That is, this is achieved by introducing a part of the pulverized raw material into the second classifying means and / or the second pulverizing means, in which the particles passing through the apparatus are fine, at a constant rate as much as possible. 4th
As shown in the figure, the raw material may be returned to the second grinding means.

Generally, fine particles have a strong cohesive force between particles or a strong adhesive force to a substance (equipment). If such agglomeration or adhesion occurs inside a pulverizer or a classifier, the mixed gas flow of the powder is turbulent. When a flow is generated, or when a frictional force or an impact force is applied, the generated heat or a mechanochemical effect causes the generation of a fusion mass and a fusion phenomenon in the apparatus. On the other hand, used as a pulverizing raw material, for example,
The coarsely pulverized toner does not show any cohesive force or adhesive force that has an adverse effect.By mixing such coarse particles, the cohesive force of the powder is reduced, and at the time of friction or impact, fusion occurs. Works to eliminate or prevent

Furthermore, this ground raw material should be ground originally, and there is no problem in mixing it. For example,
In order to reduce coagulation and adhesion, there is a method of containing or mixing colloidal silica or a low surface energy substance, but the addition of such other substances usually changes the quality of the product. Is often not preferred. This is also an effective means.

In the present invention, the feed ratio of the raw material coarse particles to the first classification means and the second classification means is preferably from 1000: 1 to 2: 1, and more preferably from 200: 1 to 3: 1. If the charging ratio is less than 1000: 1, the effect of the addition is almost negligible, meaningless and the occurrence of the fusion phenomenon cannot be prevented. Also 2:
If it is larger than 1, the abilities of the first crushing means and the first classifying means become excessive, which is not only inefficient, and also the classification accuracy in the second classifying means deteriorates, and a sharp crushed particle size can be obtained. Therefore, the effect of increasing the processing capacity of the grinding system cannot be achieved. In addition, in the case of a resin composition containing a large amount of a substance such as magnetite in coarse particles, a wear phenomenon due to the coarse particles may easily occur.

Further, in the present invention, it is significant that the second classifying means and the second pulverizing means use apparatuses having the same or lower processing capacity as the first classifying means and the first pulverizing means, respectively. That is, the second classification means and the second crushing means are usually 1: 1 to 1 in comparison with the first classification means and the first crushing means.
It is preferable to use one having a processing capacity of 3:10, and it is not preferable to use a large apparatus in terms of energy efficiency, and the investment cost is naturally large. Further, the particle size distribution of the pulverized product tends to be broad.

FIG. 5 shows an example of another system according to the present invention. This apparatus aims to improve the quantitative supply to the second classification means, improve the classification accuracy of the second classification means, and improve the pulverization efficiency. Here, the first classified fine powder collected by the first classified cyclone 10 is temporarily stored in the intermediate hopper 28 via the double damper 27,
Further, a part of the pulverized raw material is supplied quantitatively from the raw material supply device 3 to the input port 5, introduced into the intermediate hopper through the short pipe 29, and mixed with the first classified fine powder. This is supplied quantitatively to the inlet by the quantitative supply device 25.

The resin composition used in the pulverization method of the present invention is not particularly limited, but is particularly suitable when a resin having a low softening point, a low Tg, and a low melting point is used as the resin. In particular, it is an effective method for those having a melting point or softening point of about room temperature to 200 ° C.

As the binder resin used for the toner produced by the method for producing a toner of the present invention, generally known resins can be used. For example, as the binder resin for heat fixing, styrene such as styrene, α-methylstyrene, p-chlorostyrene and its substituted products, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, acrylic Octyl acid, phenyl acrylate,
Methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, diethylaminoethyl acrylate, diethylaminoethyl methacrylate,
Monocarboxylic acids having a double bond such as acrylamide and the like and substituted products thereof, for example, dicarboxylic acids having a double bond such as maleic acid, butyl maleate, methyl maleate and dimethyl maleate, and substituted products thereof For example, vinyl monomers such as vinyl chloride, vinyl acetate and vinyl benzoate, and vinyl monomers such as vinyl ethyl ether, vinyl methyl ether and vinyl isobutyl ether alone or two or more vinyl monomers Polymer or copolymer using the above,
Further, styrene-butadiene copolymer, silicone resin, polyester resin, polyurethane, polyamide, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic resin Petroleum resins, chlorinated paraffins and the like are used alone or in combination of two or more.

Further, as binders for pressure fixing, waxes (beetle wax, carnauba wax, microcrystalline wax, etc.), higher fatty acids (stearic acid, palmitic acid,
Lauric acid, etc.) higher fatty acid metal salts (aluminum stearate, lead stearate, barium stearate, magnesium stearate, zinc stearate, zinc palmitate, etc.), higher fatty acid derivatives (methylhydroxystearate, glycerol monohydroxystearate) Rate, etc.), polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, polyethylene oxide, polyisobutylene, polytetrafluoroethylene, etc.), olefin copolymer (ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer) Copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethyne-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, ionomer resin, etc.), styrene resin (low molecular weight polystyrene, Len-butadiene copolymer (monomer ratio 5-30: 95-70), styrene-acrylic compound copolymer, etc.), epoxy resin, polyester resin, rubbers (isobutylene rubber, nitrile rubber, chloride rubber, etc.), polyvinyl There are pyrrolidone, polyamide, coumarone-indene resin, methyl vinyl ether-maleic anhydride copolymer, maleic acid-modified phenol resin, phenol-modified terpene resin, silicone resin and the like, and these can be used alone or in combination.

Further, as the pigment contained in the toner produced by the production method of the present invention, for example, carbon black,
Nigrosine dye, lamp black, Sudan Black SM, First Yellow G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgazine Red, Paranitroaniline Red, Toluidine Red, Carmine FB, Permanent Bordeaux FRR,
Pigment Orange R, Risor Red 2G, Lake Red C, Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalocyanine Blue,
Pigment Blue, Brilliant Green B, Phthalocyanine Green, Oil Yellow GG, Zapong First Yellow CGG, Kaya Set Y963, Kaya Set YG,
Sumiplast Yellow GG, Zapon First Orange RR, Oil Scarlet, Sumiplast Orange G, Orazol Brown B, Zapon First Scarlet CG, Aizen Spiron Red BEH, Oil Pink OP, etc. can be applied.

To use the toner as a magnetic toner, a magnetic powder may be included in the toner. As such magnetic powder, a substance that is magnetized when placed in a magnetic field is used.
There are powders of ferromagnetic metals such as iron, cobalt and nickel, or alloys and compounds such as magnetite, hematite and ferrite. The content of the magnetic powder is based on the toner weight.
15-70% by weight is good.

Such a magnetic material may be used after being treated with a known coupling agent in order to increase the compatibility with the resin or the resistance of the toner itself. Examples of such a coupling agent include a silane-based coupling agent, a titanate-based coupling agent, an aluminum-based coupling agent, and a zirconium-based coupling agent. Good to use.

Further, various release agents may be used in the toner, and examples of such release agents include polyfluoroethylene, fluororesin, fluorocarbon oil, silicone oil, low molecular weight polyethylene, low molecular weight polypropylene, and the like. It is used in an amount of 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on the binder resin.

Further, if necessary, an abrasive, a filler, a fluidity improver, a lubricant, a conductive fine powder, and the like may be added, and a charge control agent may be added to facilitate positive or negative charge of the toner. It is also preferable to add them.

Generally, after the above-mentioned materials are uniformly dispersed by a mixing device such as a Henschel mixer or a super mixer, kneading is performed by a kneading device such as a roll mill, a kneader, an extruder, and the like, and after cooling, a hammer mill, a speed mill, etc. To obtain a raw material crushed product. Thereafter, a finely pulverized product having a desired finely pulverized particle size is obtained using the above-mentioned finely pulverizing apparatus. Further, if necessary, the particles are classified using an air classifier such as a micron separator, a DS separator, an elbow jet or the like, and used after adjusting to a desired particle size.

Further, a fluidity improver such as colloidal silica may be externally added to these toners as needed, and abrasives such as cerium oxide and strontium titanate, polyvinylidene fluoride, zinc stearate and the like may be used. Lubricant, conductive fine powder such as carbon black, iron oxide, tin oxide, etc.,
Further, a charge control agent may be externally used.

In the present invention, the raw material coarse particles of the resin composition or the crushed toner particles are usually subjected to a fine pulverizing step after coarsely pulverizing a lump. For example, coarse pulverization is performed by a hammer mill, and a mesh is attached to the hammer mill to make the particle size uniform.
Thus, the size of the mesh attached to the coarse crusher is
Usually, one having a thickness of 0.1 to 10 mm is used. If it exceeds 10 mm, it may cause clogging in the pulverizer,
When the diameter is smaller than 1 mm, the load is excessively applied to the coarse pulverizing apparatus, and the ability is not obtained. Further, mesh clogging is likely to occur.

The particle size of the raw material coarse particles or the toner crushed product depends on the type of the raw material, but the average particle size is 0.02 to 10 mm, preferably 0.03 to 10 mm.
About 5mm is good. These particle sizes are calculated by integrating several to ten standard sieves.

[Examples] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

Example 1 The integrated device system shown in FIG. 3 was used as a pulverizer. Here, a two-way automatic feeder manufactured by Koken Co., Ltd. was used as the raw material supply device 1. The first classifier 7
NPK DS-10 classifier, the second classifier 13 made by NPK
A DS-5 classifier is used as the first crushing means 8 by INPK I
As the -10 type jet crusher and the second crushing means 17, an NPK I-5 type crusher was used with some modifications.

After the above mixture was dispersed and mixed with a Henschel mixer, melt kneading was performed using a twin-screw extruder PCM65. After cooling with a cooling press roller, coarse grinding was performed using a hammer mill fitted with a 3 mmφ net to obtain a coarsely crushed toner. Next, fine pulverization was performed using the coarsely crushed material.

Here, as the DS-10 classifier as the first classifying means 7, a classifier equipped with a two-stage louver, a wide umbrella, and a steep classifying plate disclosed in Japanese Patent Application Laid-Open No. 01-207178 or the like was used.
The DS-5 classifier as the second classification means 13 was equipped with a two-stage louver. Furthermore, the first and second pulverizing means, ie, the I-10 type pulverizer and the I-5 type pulverizer, are disclosed in Japanese Patent Application No.
The accelerating tube disclosed in -289636 and the like and a conical collision member were attached. A schematic diagram of the pulverizing unit according to FIG. 6 is shown. Here, for both I-10 and I-5, those having a spread angle θ of the acceleration tube = 8.8 degrees were used. Further, the apex angle of the conical collision surface is Ψ = 160 degrees for both I-10 and I-5, and the diameter of the collision member is d- ₃ = 140 mm for I-10 and I-5.
In this case, the one having d ₃ = 90 mm was used.

The supply amount to the inlet 5 by the two-way auto feeder 1 was set to 80 kg / hr, and the supply amount to the inlet 4 was set to 4.0 kg / hr. The grinding pressure was 6.0 kg / cm ² for both 8 and 17. When the air volume at this time was measured using an air flow meter,
1-10 Nm ³ / min for I-10, 6.8 for I-15
Nm ³ / min. Classification conditions for classifiers 7 and 13 are set to 1
The finely pulverized product obtained in 6 was adjusted so that the volume average particle size was about 8.5 μm.

After finely pulverizing approximately 1000 kg of the coarsely pulverized product, the entire device was disassembled and the inside was inspected. As a result, no fusion was found anywhere. Also, about 100 g of the finely pulverized product was taken on a 200-mesh sieve every hour, suctioned from below with a vacuum cleaner and sieved, and nothing remained on the sieve.

When the particle size distribution of the finely pulverized product was measured one hour after the start, the number average particle size (hereinafter abbreviated as D1) was obtained.
D1 = 5.03 μm, the number% of particles of 4.00 μm or less (hereinafter 4.00 μm)
4.00 ↓ = 42.7%, volume average particle size (abbreviated as D4)
D4 was 8.46 μm, and the volume% of 16.0 μm or more (hereinafter abbreviated as 16.0 °) was 16.0 ° = 1.9%.

Further, when the particle size distribution of the finely pulverized product was measured every hour, the deviation of the volume average particle size was within ± 3%. The volume average particle diameter of the first classified fine powder collected by the cyclone No. 10 was D4 = 13.3 μm (within ± 3.0%).

In the present specification, unless otherwise specified, the particle size distribution is measured by a Coulter Counter TA-II (Coulter) using a 100 μm aperture as standard.

This finely pulverized product was classified using an elbow jet classifier (manufactured by Nittetsu Mining Co., Ltd.), and D1 = 6.45 µm, 4.00 ↓ = 11.2
%, D4 = 8.26μm, 16.0 ↑ = 2.8%, 81.5%
In a yield of 0.7% by weight of colloidal silica treated with aminosilicone oil was externally added and mixed with the classified product to prepare a toner sample.

A copy test was performed using this toner. As a test machine, NP = 4835 manufactured by Canon Inc. was used. 23 ℃, 65% RH
As a result of conducting a continuous image endurance test of 100,000 sheets in a normal environment, the image density of the first 100 sheets was 1.40 (by Macbeth reflection densitometer), and the image density during the endurance was within 1.40 ± 0.05. As a result, the decrease in density due to toner replenishment when the toner replenishing device worked was within 0.05, and had little effect on the image. No cleaning failure, drum fusion, filming, etc. occurred during the durability.

Comparative Example 1 A comparative test was performed using the crushed product of Example 1 and the same apparatus. No crushed material is supplied to the inlet 4 and the inlet 5
Was supplied at 80 kg / hr. When the particle size distribution one hour after the start was measured, D1 = 5.01 μm, 4.00 ↓
= 43.3%, D4 = 8.41 μm, 16.0 ↑ = 1.8%, which were almost the same as those in Example 1. After about 3 hours, the particle size began to become fine (D4 = 8.15 μm ... 3 hours), and after 40 minutes, the level meter attached to the short tube 20 turned on. After disassembly and inspection, there was powder inside,
When I-5 was disassembled, fusion occurred on the collision surface and in the grinding chamber (D4 after 3.5 hours = 7.12 µm).

Further, the louvers of the classifier 13 were also fused, and the louvers had a narrower gap. It was considered that the grain size became finer.

Examples 2 to 5 and Comparative Examples 2 and 3 Table 1 shows the test results when the supply amount was varied using the same crushed material and the same apparatus according to Example 1.

Example 6 Polyester resin (acid value 9.0, softening point 103 ° C., Mw = 1.3
× 10 ⁴ ), and a pulverization experiment was performed using the same apparatus as in Example 1. However, the apex angle of the conical collision surface is Ψ = 12
The thing of 0 degree was used. Impact member diameters d ₃ are 140 each
mm and 90mm. The same accelerator tube was used. As for the polyester resin, a lump was previously crushed using a hammer mill provided with a 3 mmφ net and used as raw material coarse particles. Classifiers 7 and 13 were finely pulverized to a volume average particle size of about 7.5.
It was set to be μm. 85 from the inlet 5
kg / hr and the supply amount from the inlet 4 were set to 7.0 kg / hr.

After finely pulverizing about 400 kg of raw material coarse particles, the inside of the apparatus was inspected, but no fusion occurred. One hour after the start, the particle size distribution was as follows: D1 = 4.64 μm, 4.00 ↓ = 48.7
%, D4 = 7.52 μm, 16.0 ° = 0.5%, and the volume average particle size was in the range of ± 3.5% until completion.

Comparative Example 4 A pulverization test was performed in the same manner as in Example 6, except that the supply of the raw material coarse particles from the charging port 4 was omitted. 25 minutes after the start, no pulverized product was discharged, and the level gauge attached to the short pipe 20 turned on. When the equipment was disassembled and inspected, a large number of fused masses of several mm to 5 cm in size came out from inside. The level meter was turned on because this blocked the supply port of the material to be crushed shown in FIG.

Example 7 Using the above materials, a core material of the microcapsule toner was prepared. This mixture was melt-kneaded in a roll mill, cooled, and coarsely ground using a hammer mill fitted with a 3 mmφ net to obtain a raw material coarsely ground product.

Next, using this roughly crushed material, fine pulverization was performed by the same apparatus as in Example 1. The conditions of the classifiers 7 and 13 were set so that the volume average particle size of the finely pulverized product was about 11.5 μm. Feeding was performed at a supply rate of 45 kg / hr to the supply port 5 and 15 kg / hr to the supply port 4. The grinding pressure was 4.0 kg / cm ² . After one hour, the particle size distribution of the finely pulverized product was measured.
Number of particles of μm, 6.35μm or less (hereinafter abbreviated as 6.35 ↓)
6.35 ↓ = 66.6%, D4 = 11.52 μm, and the volume percentage of 20.2 μm or more (hereinafter abbreviated as 20.2 °) 20.2 ° = 2.7%.

After grinding about 500 kg, the inside of the device was inspected, but no fusion was found. The deviation of the volume average particle size is ± 3.
%.

Classify the above finely pulverized material with an elbow jet classifier, D1
= 8.87μm, 6.35 ↓ = 19.8%, D4 = 11.49μm, 20.2 ↑
= 0.9%.

Further, 0.6 wt% of colloidal silica was externally added to obtain a core material of the microcapsule toner. Next, encapsulation was performed using this core material.

A resin solution was prepared using the above materials. Such a solution 56
2.1 kg of acetic acid was added per kg and cooled to -25 ° C. Here, 10 kg of the above core material was added and stirred with a homomixer. Further, 30 kg of water was slowly dropped therein. After the completion of the dropping, the solid was recovered by filtration. Further, the encapsulated product was washed with sufficient water, filtered and dried to obtain a microencapsulated product. To this, 1.0 wt% of colloidal silica was externally added to obtain a microcapsule toner.

Comparative Example 5 Using the coarsely pulverized material used in Example 7, a pulverization test was carried out in the same manner with a feed rate of 45 kg / hr from the supply port 5 and no supply from the supply port 4. About an hour after the start, the level gauge on the short tube 20 turned on. When the inside of the apparatus was inspected, the inside of the crusher 17 was full of fused material, and the supply port of the material to be crushed was closed with the fused piece.

[Effects of the Invention] As described above, according to the pulverizing method and the method for producing a toner of the present invention, even if a pulverized material having a low softening point, a low Tg, and a low melting point is used, a complicated apparatus is not used. In addition, it is possible to easily prevent the fusing phenomenon with a small investment without using costly methods such as freezing and pulverization, and to pulverize a resin composition that can be produced stably, and to obtain a homogeneous toner of good quality at all times. Can be obtained. That is,. It is possible to stably pulverize the resin composition without fusing or the like, and to prevent the occurrence of powder clogging in the apparatus body, and to reduce the cost of the resin composition at low cost without reducing production efficiency. A crushed product can be obtained.

. Fine powder toner can be stably obtained without generation of a fused material, and a constant and uniform toner can always be obtained. Further, a toner having a finer particle size can be obtained at low cost without lowering the production efficiency.

There is such an effect.

[Brief description of the drawings]

FIG. 1 is a graph showing an experimental result of a pulverization test performed by the conventional type pulverization system shown in FIG. 7, and is a graph showing a relationship between a fusion generation treatment amount and a volume average particle diameter of a pulverized product. FIG. 2 is an example of a flowchart showing the pulverizing system of the present invention. FIG. 3 schematically shows an example of the pulverizing system shown in FIG. FIG. 4 shows an example of a pulverizing system according to the present invention, in which a pulverized raw material is supplied to a position different from that in FIG. FIG. 5 shows another example of the pulverizing system according to the present invention. FIG. 6 is a schematic diagram showing the internal structure of the crusher. FIG. 7 is a flowchart showing a conventional grinding system. FIG. 8 is a flowchart showing a conventional pulverizing system when two classifying means are provided. FIG. 9 is a flowchart showing a conventional pulverization system designed to improve the pulverization efficiency. DESCRIPTION OF SYMBOLS 1 ... Material hopper, 2,3 ... Material feeder 4,5 ... Inlet 6,9,12,14,18,21,22,30 ... Piping 7 ... First classifier, 8 ... First crusher 10 ... 1st classifier cyclone 11… Injection feeder 13… 2nd classifier 15… Second classifier cyclone 16… Pulverized product discharge, 17… Second classifier 19,20,29… Short tube, 23,24… Level meter 25… Quantitative feeder, 26… Inlet 27… Double damper, 28… Intermediate hopper θ… Acceleration tube divergence angle, Ψ… Apex angle of collision surface d ₃ … Diameter of collision member

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Mitmura 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Masayoshi Kato 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (6)

(57) [Claims] In a method of pulverizing a resin composition comprising a resin alone or a resin and one or more additives, raw material coarse particles of the resin composition are introduced into a first classifying means to obtain a first classifier.
The first coarse powder is classified into a coarse powder and a first classified powder, and the classified first coarse powder is introduced into a first pulverizing means to be pulverized, and the pulverized product of the obtained first coarse powder is mixed with raw material coarse particles in the first classifying means. Into the second classifying means by introducing the classified first classified powder together with the raw material coarse particles into the second classified powder and the second classified powder, and classify the classified second classified powder into the second classified powder. (2) A method for pulverizing a resin composition, comprising introducing into a pulverizing means and pulverizing, and introducing the obtained pulverized second coarse powder into a second classifying means. 2. A method for producing toner particles by dissolving and kneading a composition containing at least a binder resin and a colorant, solidifying it by cooling, pulverizing the solidified substance by a pulverizing means, and then classifying the solidified substance. After the solidified product is coarsely pulverized into a coarsely pulverized product, the coarsely pulverized product is introduced into a first classifying means, and the first coarse powder and the first
Classified into coarse powder, the classified first coarse powder is introduced into a first pulverizing means and pulverized, and the pulverized material of the obtained first coarse powder is introduced into the first classifying means together with the coarsely pulverized material to classify the first coarse powder. And introducing the classified first classified powder together with the crushed material into the second classifying means,
Classifying into a coarse powder and a second classified powder, introducing the classified second coarse powder into a second crushing means and pulverizing, and introducing the obtained crushed second coarse powder into the second classifying means, A method for producing a toner, characterized in that the second classifying powder is obtained as finely divided material. 3. The first pulverizing means, the first classifying means and the second pulverizing means.
The ratio of the capacity of the crushing means and the capacity of the second classification means is 1: 1 to 1: 0.3
The method for pulverizing a resin composition according to claim 1, wherein: 4. The first pulverizing means, the first classifying means and the second pulverizing means.
The ratio of the capacity of the crushing means and the capacity of the second classification means is 1: 1 to 1: 0.3
The method for producing a toner according to claim 2, wherein 5. The resin composition according to claim 1, wherein the ratio of the raw material coarse particles to the first classification means and the second classification means is from 1000: 1 to 2: 1. Grinding method. 6. The method for producing a toner according to claim 2, wherein the ratio of the raw material coarse particles to the first classifying unit and the second classifying unit is 1000: 1 to 2: 1. .