JPH0666033B2 - Toner powder manufacturing method and apparatus system for manufacturing toner powder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for efficiently producing a toner powder having a sharp particle size distribution and an apparatus system therefor.

[Conventional technology]

Conventionally, a combination of one classifier and one crusher or a combination of two classifiers and one crusher has been known as a method for finely pulverizing toner. As an example, a high pressure air flow is used as a jet nozzle. From a jet mill, which entrains the raw material particles in the jet air stream, and promotes pulverization by mutual collision of the particles or collision with a wall or other colliding body. Means 1 and 2 are combined and provided for grinding. FIG. 2 and FIG. 3 are conventional examples. In FIG. 2, the raw material is supplied through the raw material supply pipe 1, and the raw material is introduced into the classifying means together with the pulverized material and divided into coarse powder and fine powder. The coarse powder is pulverized through the pulverizing means and then introduced into the classifying means again. On the other hand, the fine powder is discharged out of the system as a product.

However, in this system, in addition to the powder of the raw material, the powder to be supplied to the classifying means is supplied with the toners of various particle sizes in the process of pulverizing by circulating between the pulverizing means and the classifying means. However, the particle size is very broad, and it is operated under a very heavy load. Therefore, the classified fine powder, that is, the pulverized product, has many coarse particles which adversely affect the quality.

On the other hand, on the coarse powder side that is returned to the pulverization again, a large amount of fine powder that does not need to be pulverized originally is mixed, and since these fine powders are further pulverized, the proportion of the fine powder in the pulverized product increases. As a result, agglomerates of fine powder may be generated, and the yield is low even if fine powder is obtained in the classification step of the next step to obtain a desired particle size. Further, as described above, the proportion of coarse powder, fine powder, etc. is large, so the image obtained using the developer thus prepared has low density, has a lot of fog, and has white spots. Has the problem of. Further, there are problems that the classification efficiency is poor and the pulverization energy efficiency is poor.

As a means for improving the above, as shown in FIG. 3, by providing a second classifying means, the first classifying means removes fine powder at a relatively coarse classification point, and the second classifying means further removes fine powder. Attempts have been made to improve the classification accuracy of the classifier attached to the crusher. Although this solves the above problems,
It is not sufficient yet, and the number of crushing means and transportation means 5 from the first classifying means to the second classifying means is increased,
There have been problems that the process is complicated and the investment amount is nearly doubled, and the running cost of energy for operating the first classifying means, the transporting means and the like increases.

[Problems to be solved by the invention]

The present invention solves the above-mentioned various problems in the conventional toner fine pulverization method, and its purpose is to provide a toner for electrostatic development which has a uniform and fine particle size distribution and which can achieve high image density. An object of the present invention is to provide an efficient manufacturing method and an apparatus system therefor.

[Means for solving problems]

Specifically, the present invention melt-kneads a composition containing at least a binder resin and a colorant, cools and solidifies the kneaded product,
A method of producing a pulverized raw material by pulverizing a solidified product, and classifying the produced pulverized raw material to produce toner powder. In the method, the pulverized raw material is introduced into a first air classifying means to produce a first classified coarse powder and a first classified fine powder. 5 to 10 kg of the first classified coarse powder obtained by the wind power distribution to the and
The first pulverized product of the first classified coarse powder obtained by pulverizing with a pulverizing air pressure in the range of 1 / cm ² is introduced into the first air classifying means together with the pulverizing raw material to perform the air class, and the first classified fine powder is classified. The second
Introduced into the air classifier, the second class coarse powder and the second class fine powder are classified by the wind force, and the obtained second class coarse powder is composed of a jet type grinding means having a processing capacity lower than that of the first grinding means. Introduced into the second crushing means, crushing with a crushing air pressure in the range of ² to 6 kg / cm ² so that the impact force is weaker than the impact force at the time of crushing in the first crushing means. The present invention relates to a method for producing toner powder, which comprises introducing a second pulverized product of classified coarse powder into a first classification means.

Furthermore, the present invention melt-kneads a composition containing at least a binder resin and an adhesive, cools and solidifies the kneading, pulverizes the solidified product to produce a pulverized raw material, and classifies the produced pulverized raw material by a classification means. And a device system for producing toner powder by means of a first wind force classification means,
A first crushing means, a second wind power classifying means and a second crushing means are provided, and the first wind power classifying means classifies the introduced pulverized raw material into the first classification coarse powder and the first classification fine powder by wind classification. The first pulverizing means comprises a jet type pulverizing means for pulverizing the classified first classified coarse powder with an impact force by a pulverizing air pressure in the range of 5 to 10 kg / cm ^2. And the second wind power classification means is the first wind-classified first
It is a classifying means for classifying the classified fine powder into a second classified coarse powder and a second classified coarse powder by an air force, and the second pulverizing means comprises a second air classified coarse powder in the first pulverizing means. A pulverizing means comprising a jet type pulverizing means having a lower processing capacity than the first pulverizing means for pulverizing at an pulverizing air pressure in the range of ² to 6 kg / cm ² so that the impact force is weaker than the impact force at the time of pulverizing. The apparatus system is configured such that the first crushed material of the first classified coarse powder crushed by the first crushing means is used together with the crushing raw material.
The apparatus further comprises: an introducing means for introducing into the wind power classifying means; and an introducing means for introducing into the first wind power classifying means the second pulverized product of the second classified coarse powder pulverized by the second pulverizing means. And an apparatus system for producing toner powder.

The method of the present invention is for pulverizing and classifying a melt-kneaded composition, and FIG. 1 is a flow chart showing the outline of the method.

That is, in the method of the present invention, the pulverized material and the raw material pulverized by the first pulverizing means and the second pulverizing means are sent to the first classifying means, and the first classified coarse powder classified by the first classifying means is a jet type. It is introduced into the first crushing means composed of crushing means and is crushed.

The first classified fine powder classified by the first classification means is further classified into the second classified coarse powder and the second classified fine powder by the second classification means,
The second classified coarse powder is crushed by the second crushing means composed of a jet type crushing means to generate a second crushed product, and the generated second crushed product is introduced into the first classification means together with the raw material and the first crushed product. To be done.

On the other hand, the second classified fine powder is discharged to the outside of the system as a crushed finished product.

In order to carry out the method described above, it is usual to use an integrated device system in which mutual devices are connected by pipe means or the like, and a preferable example of such a device is shown in FIG.
The integrated device shown in FIG. 4 includes a first crusher 4, a first wind classifier 3, a first classification cyclone 6, an in-transportation feeder 7, a second wind classifier 9, and a second crusher 13. Second
The classification cyclone 11 is connected by pipe means. In this apparatus, so-called powder raw material is introduced into the first wind power classifier 3 through the raw material inlet 1 and the raw material supply conduit 2, and the classified first coarse powder is fed to the first crusher 4. It is introduced, pulverized, and again introduced into the first wind power classifier 3 via the conduit 2.

On the other hand, the first finely divided powder obtained by the classification is collected in the collecting cyclone 6 through the conduit 5, taken out from the cyclone by the ingestion feeder 7, and then fed into the second wind classification means 9 through the conduit 8. It is introduced and classified into the second classified coarse powder and the second classified fine powder. The classified second coarse powder is the second crusher
Crushed in 13 to produce a second crushed product, which is a conduit
It is introduced into the first wind power classifier 3 via 14 together with the raw material and the first crushed product.

On the other hand, the second classified fine powder is collected by the collecting cyclone 11 through the conduit 10 and discharged from the crushed product discharge port 12.

As the crushers 4 and 13, a jet crusher can be preferably used, as described in Examples below, but it is required that the crusher itself is a device capable of crushing to a target particle size. As a machine, Pneumatic Japan PJM-I, Hosokawa Micron Micron Jet, Jet-O-Mizer, Blaw-Knox, Trost Jet Mill,
Others can be used.

Further, as the wind force classifiers 3 and 9, a DS separator manufactured by Japan New Matic Co., Ltd., a turbo classifier manufactured by Nisshin Engineering, a MS separator manufactured by Hosokawa Micron, or another wind force classifier can be used.

According to the present invention, compared to the conventional device, it is possible to add a jet crusher with a small weight (10%).
It is possible to significantly increase the processing capacity by 50% to 100%. In terms of power, compared with the conventional example (FIG. 3), the power of the second crushing means 5 increases, but other power amounts such as wind power classifying means that use a large amount of power do not change, so the generated crushing The energy consumption per finished product weight can be significantly reduced by 15% to 30%.

Another advantage of the present invention is that, when crushed by the second air crushing means by the second crushing means, unlike the conventional case, only fine particles close to the toner particle size are crushed and sent to the classification. Therefore, excessive pulverization can be prevented, and generation of ultrafine powder of 2 μm or less and fine powder aggregates can be prevented, and a pulverized product having a sharp particle size distribution can be obtained. Furthermore, classification is performed in the next step, and the yield of the classified product when removing fine powder of 7 to 8 μm or less is improved by 3 to 5%, and the presence of ultrafine powder and fine powder in the classified product is small.

Further, in the present invention, it is preferable that the second air classifying means and the second crushing means use devices having a processing capacity lower than that of the first classifying means and the first crushing means, respectively. That is, it is not preferable to use a large apparatus in the second step, because there is no energy efficiency and the particle size distribution becomes broad.

Another feature of the present invention is that the impact force of the second crushing means during crushing is controlled to be weaker than the impact force of the first crushing means during crushing. As one specific example,
The air pressure of the grinding air of the first grinding means of the jet mill is 5 to
It is crushed by raising it to 10 kg / cm ^2, and the second crushing means has a lower 2-6 kg / cm ² than the air pressure of the crushing air of the first crushing means.
By crushing at a low level, it becomes possible to obtain a crushed product having a smaller particle size distribution and less generation of fine powder and ultrafine powder. Further, the product obtained by further processing the crushed product obtained by such a method in the subsequent steps also has good fluidity, the image quality is higher than that produced by the conventional process, and the background fog is high. Also, it is possible to obtain the one with less torichi around the letters.

Further, in order to make the present invention more effective, it is important that a means for preventing the pulsation of the powder to be sent is also used in combination with the second wind force classifying means. As shown in Fig. 5, it is discharged below the first classification cyclone 6 by the double damper 21, and the discharged first classification fine powder is quantitatively supplied by the feeder 15 which quantitatively supplies it. A method of dispersing and sending to the second wind force classifying means 9 is exemplified.

Here, the feeder 15 sets the feed amount to 1.0 to 1.5 times, preferably 1.1 to 1.3 times the amount of the powder sent through the first classification cyclone 6, and the level meter 16 sets the feeder amount.
If the first fine powder in 15 is not detected, the feeder 15
Stop and drive when detected. Further, as a further example of the means for preventing pulsation, as shown in FIG. 6, a large amount of powder flows by providing a squeezing means at the powder supply port to be supplied to the crushing means of FIGS. 1 and 2. It is also effective to use the as a means to prevent.

The present invention will be described in detail in the following examples.

Example 1 FIG. 5 is an example of carrying out the present invention. As a raw material, a mixture of toners pulverized by a hammer mill having a 3 mm screen was used. The crusher 4 is an I-10 type jet mill manufactured by Japan Newmatic Industrial Co., Ltd., the crushing pressure is set to 6 kg / cm ² , and the second crusher 13 is manufactured by Nippon Newmatic Industrial Co. , I-5 type jet mill, and the grinding air pressure was set at 4.5 kg / cm ² . As the first wind power classifier 3, a DS-10 type wind power classifier manufactured by Nippon Neumatic Co., Ltd. is used, and the classification air amount is 20 m ³ /
min, and the particle size of the first classified coarse powder and the first classified fine powder is 30 to 50μ in terms of volume average diameter by a coulter counter.
m, 15 to 30 μm. Second wind classifier 9
As the above, a DS-5 type wind power classifier manufactured by Nippon New Matic Co., Ltd., which is smaller than the first wind power classifier 3, is used, the classification air amount is set to 10 m ³ / min, the second classification coarse powder and the second classification fine powder ( The crushed product) was set to have a particle size of 20 to 35 μm and 10 to 12 μm by the Coal counter, respectively, and the results shown in Table 1 were obtained.

3 Cohesion Degree The measurement method of the cohesion degree used in the present invention is a method of placing toner on a sieve and applying vibration to measure the ratio of the toner remaining on the sieve.

According to this method, the larger the proportion of the toner remaining on the sieve, the greater the degree of toner aggregation and the more the toner particles aggregate and behave cheaply. Specifically, using a powder tester manufactured by Hosokawa MicrometeX Laboratory, temperature 25 ± 1 ℃,
Measured at a humidity of 60 ± 5%.

The sieves of 60 mesh, 100 mesh and 200 mesh are lined up in this order and set on the vibrating table. 60g of 2g toner
Place on a sieve of a mesh and apply a voltage of 47V to the vibrometer to apply vibration for 40 seconds.

After the completion, the weight of the toner remaining on each sieve was measured, and weights of 0.5, 0.3, and 0.1 were applied to each, and the degree of aggregation was expressed as a percentage.

Example 2 FIG. 4 is an example of carrying out the present invention.
The kneaded product for toner was coarsely crushed with a 3 mm screen Hammar mill. The first crusher 4 is an I-10 type jet mill manufactured by Japan New Matic Co., Ltd., and the crushing air pressure is 6 kg.
/ Cm ² and the second crusher 13 has a processing capacity lower than that of the first crusher 4 manufactured by Japan Newmatic Co., Ltd. I-
The grinding air pressure was set to 5 kg / cm ² with a type 5 jet mill and used. As the first wind power classifier 3, Hosokawa Micron MS-
Using a type 3 wind classifier, the classification air amount is 25m ³ / min,
The particle sizes of the first classified coarse powder and the first classified fine powder are 30 to 50 μm and 15 to 30 in terms of volume average diameter by a Coulter counter, respectively.
It was set to be μm. The second wind power classifier 9 is manufactured by Hosokawa Micron, which is smaller than the first wind power classifier 3.
Using the MSS-1 type air classifier, the classification air amount is set to 15 m ³ / min, and the particle size of the second classification coarse powder and the second classification fine powder (crushed product) is 20 to 20 in terms of volume average diameter by a call counter.
The results shown in Table 2 were obtained by setting 35 μm and 10 to 12 μm.

[Effects of the Invention] The manufacturing method and apparatus system of the present invention can efficiently produce toner powder capable of generating a developed image with high image density.

[Brief description of drawings]

FIG. 1 is a flowchart of the present invention, FIG. 2 is a diagram showing an example of a conventional example, FIG. 3 is a diagram showing an example of a conventional example, and FIG. 4 is a diagram showing an example of an example (example 2 is a flow chart), FIG. 5 is a view showing an example of the embodiment (flow chart of the first embodiment), FIG. 6 is a view showing an example in the case where a crusher is provided with a pressing means, and FIG. It is a figure which shows one specific example of a comparative example. 1 to 12 are the same as those in FIG. 4, and 19 is a double damper 20 that takes out the coarse powder from the second classifying means 9 and discharges it, and is a shout for sending the second coarse powder to the crusher. In FIG. 6, 22 is the main body of the crusher, 23 is the hopper of the crusher, 24 is a conical squeezing valve attached to the powder supply port, 25 is an air ejector for accelerating the powder by high pressure air, and 26 is A collision plate that collides the accelerated powder and pulverizes the powder, and 27 is an outlet for the powder and the air.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoto Kitamori 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP-A-61-128254 (JP, A) Japan Powder Industry Second Edition, "Handbook of Classification Equipment Technology," edited by the Association, Industrial Technology Center (Sho 53-8-1), p. 429-431, 549-554 Tatsuo Tanaka, "Introduction to Powder Process (Revised Edition)", Engineering Book (sho 56-3-10), P. 193, "Special Issue on Chemistry 31 Physical Properties and Engineering of Powder", Kagaku Dojin, (Sho 42-11.1), P. 164 Japan Science and Technology Co., Ltd., "Recent Electrophotographic Development System and Toner Material Development and Practical Application Comprehensive Technical Data Book (Sho 60-9-30), pp. 251-252.

Claims (2)

[Claims] 1. A toner containing a binder resin and a colorant, which is melt-kneaded, the kneaded product is cooled and solidified, the solidified product is crushed to produce a pulverized raw material, and the produced pulverized raw material is classified. In the method for producing powder, the pulverization raw material is introduced into the first air classifying means, and the first class coarse powder and the first class fine powder are air classified, and the obtained first class coarse powder is constituted by a jet type pulverizing means. Introduced into the first crushing means and crushing with a crushing air pressure in the range of 5 to 10 kg / cm ² , and introducing the obtained first crushed material of the first classified coarse powder into the first wind power classifying means together with the crushing raw material. The first classified fine powder subjected to the wind power classification is introduced into the second wind classification device to perform the wind classification into the second classified coarse powder and the second classified fine powder, and the obtained second classified coarse powder is the first classified fine powder. The first powder is introduced into the second pulverizing means which is a jet type pulverizing means having a processing capacity lower than that of the pulverizing means. Trituration with grinding air pressure in the range of 2~6kg / cm ² so that the weak impact force than the impact force at the time of grinding in section, a second pulverized second classifying coarse powder obtained first classifying means A method for producing toner powder, comprising: 2. A composition containing at least a binder resin and a colorant is melt-kneaded, the kneaded product is cooled and solidified, the solidified product is crushed to produce a pulverized raw material, and the produced pulverized raw material is classified by a classification means. And an apparatus system for producing toner powder by means of a first air classifying means, a first crushing means,
The second wind power classification means and the second crushing means are provided, and the first wind power classification means is a classification means for classifying the introduced pulverized raw material into the first classification coarse powder and the first classification fine powder by wind power. The first crushing means uses 5 to 10 kg of the classified first classified coarse powder.
Is a crushing means comprising a jet-type crushing means for crushing with an impact force by a crushing air pressure in the range of / cm ² , wherein the second wind power classifying means is a wind power classifying first classifying fine powder and a second classifying coarse powder. And a second classifying fine powder for classifying by wind force, wherein the second crushing unit has an impact weaker than the impact force at the time of crushing the wind-classified second classified coarse powder by the first crushing unit. The crushing means comprises a jet-type crushing means having a lower processing capacity than the first crushing means for crushing with a crushing air pressure in the range of ² to 6 kg / cm ² so as to obtain a force. Introducing means for introducing the first pulverized product of the first classified coarse powder pulverized by the first pulverizing means together with the pulverization raw material into the first air classifying means, and the second coarse pulverized by the second pulverizing means. Introducing means for introducing the second pulverized product of the powder into the first wind power classification means System for producing a toner powder which is characterized by preparative, and further comprising.