JP2003223014A - Method of manufacturing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing toner which can mass-produce toner particles synthesized in an aqueous medium without deterioration of quality and with good efficiency. <P>SOLUTION: The manufacturing method which has a process for cleaning and dehydrating the toner synthesized in the aqueous medium, dispersing the volatile components of the resulted moist toner particles while continuously supplying the toner particles into a hot air current as primary drying and substantially removing moisture therefrom while feeding the toner particles to the parallel flow with the hot air current and a process for removing the other moisture components by reduced pressure heat treatment accompanied by agitating as secondary drying, is characterized in that there are a plurality of units of the apparatus to perform the secondary drying with respect to the apparatus for performing the first drying in this method. The toner particles from which moisture is continuously removed by primary drying are supplied to a first vessel where pressure reducing and heating are possible and at the point of the time when a prescribed amount of the toner particles are accumulated in the vessel, a reduced pressure state is formed in the vessel and the reduced pressure heat treatment is started and thereafter the supply from the first drying to the second drying is switched to a second vessel where pressure reducing and heating are possible, and at the point of the time when a prescribed amount of the toner particles are likewise accumulated, the reduced pressure state is formed and the reduced pressure heat treatment is started. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for developing a latent image and a method for producing a toner used in a toner jet recording method.

[0002]

BACKGROUND OF THE INVENTION Electrophotography is described in U.S. Pat. No. 2,297,6.
As described in Japanese Patent No. 91, etc., a number of methods are known, and generally, a photoconductive material is used to form an electric latent image on a photoreceptor by various means, The latent image is developed with toner, and the toner image is transferred to a transfer material such as paper, if necessary, and then fixed by heating, pressure, solvent vapor or the like to obtain a copy. Further, as a method of developing with toner or a method of fixing a toner image,
Conventionally, various methods have been proposed, and methods suitable for respective image forming processes have been adopted.

Conventionally, as a toner used for these purposes, a coloring agent such as a dye and a pigment is generally melt-mixed in a thermoplastic resin and dispersed uniformly, and then a desired particle diameter is obtained by a fine pulverizer and a classifier. Has manufactured toner.

While this method of manufacture can produce fairly good toners, it does have certain limitations, ie, the choice of toner materials. For example, the resin colorant dispersion is sufficiently brittle,
It must be able to be milled with economically feasible manufacturing equipment. However, if the resin colorant dispersion is made brittle in order to meet these requirements, the particle size range of the particles formed when the particles are actually pulverized at a high speed tends to be wide, and in particular, a relatively large proportion of fine particles is The problem of being included in. Furthermore, such a brittle material is likely to undergo further fine pulverization or pulverization when used for developing such as a copying machine. Further, in this method, it is difficult to completely uniformly disperse solid fine particles such as a colorant in the resin,
Depending on the degree of dispersion, fog may increase, image density may decrease, and color mixture and transparency may be poor. Therefore, attention must be paid to dispersion. In addition, the exposure of the colorant on the fracture surface may cause fluctuations in the developing characteristics.

On the other hand, in order to overcome the problems of toner by the pulverization method, Japanese Patent Publication Nos. 36-10231 and 43-43
Various polymerization toners and methods for producing the same have been proposed, including toners by the suspension polymerization method disclosed in Nos. 10799 and 51-14895. For example, in the suspension polymerization method, a polymerizable monomer, a colorant, a polymerization initiator and optionally a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed to form a monomer composition. After that, this monomer composition is dispersed in a continuous phase containing a dispersion stabilizer, for example, an aqueous phase using a suitable stirrer, and a polymerization reaction is simultaneously carried out to obtain toner particles having a desired particle size. obtain.

Since this method does not include a crushing step at all, the toner does not need to be brittle, a soft material can be used, and the classification step can be omitted, thereby saving energy. The cost reduction effect is great, such as reduction of time and improvement of process yield.

Further, in recent years, there has been a demand for multifunctionalization of the toner itself such as high image quality, full color and energy saving of copying machines and printers. For example, in order to support high resolution and high resolution digital systems with higher image quality, finer particle size of toner particles, improvement of transparency of OHP images due to full colorization, and low temperature fixing due to energy saving. It is required to include a softening point substance and shape toner particles that are effective in improving transfer efficiency to a transfer material. As a means for fulfilling these requirements, a toner by a polymerization method can be mentioned.

On the other hand, in the polymerization method, the reaction form including the polymerization method toner increases the viscosity of the polymerization reaction system as the polymerization progresses, and it becomes difficult for radicals and polymerizable monomers to move, so that the polymerization in the polymer occurs. A large amount of the polymerizable monomer component tends to remain. In particular, in the case of a suspension polymerization method toner, a component such as a dye, a pigment (especially carbon black), a charge control agent and a magnetic substance which may inhibit the polymerization reaction is contained in the polymerizable monomer system. Since it is present in a large amount in addition to the body, the unreacted polymerizable monomer is more likely to remain.

If a large amount of a component that acts as a solvent for the binder resin, not limited to the polymerizable monomer, is present in these toner particles, the fluidity of the toner is deteriorated and the image quality is deteriorated. Cause decline. In addition to the ability to be directly involved as a toner, especially when an organic semiconductor is used as a photoconductor, in addition to the phenomenon of toner fusion to the photoconductor drum, it is accompanied by deterioration of the photoconductor such as memory ghost and image blur. May cause problems. In addition to such matters relating to the performance of the product, there is a problem that the polymerizable monomer component volatilizes during fixing to give off a bad odor.

In order to improve the above, as shown in JP-A-7-92736, the residual amount of the polymerizable monomer present in the toner particles is reduced to 500 ppm or less to improve the image quality. It is proposed to produce further improvement effects.

Further, downsizing of copying machines, printers, etc.,
With personalization, the restrictions on the device are increased, the load on the above-mentioned problems is increased, and the interest in the environment is also increased, and it is required to reduce the VOC derived from toner particles generated in fixing and the like. Therefore, it is preferable to reduce the residual amount of the polymerizable monomer present in the toner particles to 100 ppm or less.

As a method for further reducing the residual amount of the polymerizable monomer in the toner particles, it is possible to use a known means for accelerating the consumption of the polymerizable monomer used in producing the binder resin by the polymerization method. You can For example, as a method of removing the unreacted polymerizable monomer, a method of washing with a highly volatile organic solvent that does not dissolve the toner binder resin but does dissolve the polymerizable monomer and / or the organic solvent component; A method of washing with an acid or alkali; a solvent component that does not dissolve the foaming agent or the polymer is added to the polymer system, and the resulting toner is made porous to reduce the volatilization area of the polymerizable monomer and / or the organic solvent component inside. Sieving method; and main synthetic monomer and / or under dry condition
Alternatively, a method of volatilizing an organic solvent component may be used, but it is difficult to select a solvent such as elution of a toner constituent component due to deterioration of toner capsule property and residual property of the solvent. The most preferred method is to volatilize the solvent component.

Conventionally, the toner particles after solid-liquid separation of the suspension in which the polymerization reaction has been completed are generally dried by using a vacuum dryer, a gas stream dryer or the like.

Further, when drying is performed using a vacuum dryer from the beginning, a very long drying time is required to sufficiently reduce water content and unreacted polymerizable monomer, resulting in deformation of particles and particles. There is a possibility that fusion between the particles will occur, and as a result, lumps will occur due to the aggregation of the particles, and the image characteristics will deteriorate.

On the other hand, the vacuum type dryer is an indirect heating type having a heat transfer surface in almost all cases. In this case, when a small scale device and a large scale device are compared, they are charged in the vacuum dryer. There is a demerit that the ratio of the heat transfer area to the sample to be dried becomes smaller as the scale increases, and the drying time required on the small scale requires a longer time on the large scale. As a result, when attempting to scale up, the above-mentioned problems caused by the long thermal history become even more pronounced.

In vacuum drying, it has been a problem for many engineers to reduce the extension of the drying time caused by the difference in scale, and the same applies when this is used for drying the polymerized toner. It was

Further, in the case where the air flow dryer alone is used for drying,
It is possible to disperse the wet colored polymer particles in a high-speed hot air stream and at the same time perform drying while sending them in a parallel flow, and to supply the wet colored polymer particles continuously in the high-speed hot air stream. Although it is a highly efficient dryer, it is difficult to remove the unreacted polymerizable monomer because the drying time is instantaneous.

Further, a method has been proposed in which volatile components are reduced by performing vacuum drying after airflow drying. However, after the airflow drying, the heated toner particles are kept in a vacuum dryer while being kept warm. By adding, it is possible to reduce the extension of the drying time caused by the scale difference, and it is possible to perform the drying efficiently. However, since one is a continuous type and the other is a batch type, unless a separate device for receiving the toner particles is provided between the air flow drying and the vacuum drying, the air flow drying operation can be performed during the vacuum drying. It must be stopped and the system cannot operate continuously. Therefore, as a means for receiving toner, as shown in FIG.
It is possible to have two. Further, as described above, it has been proposed to prepare a heated hopper as a means for charging the vacuum dryer while maintaining a warm state, but if a large amount of toner particles are kept in a warm state in the hopper, However, there is a possibility that problems such as quality deterioration and blocking may occur.

As described above, an efficient volatile matter removal process can be formed by combining a continuous dryer and a batch dryer, but the system is efficient in a continuous or nearly continuous form, and further It has been an issue so far to carry out production without quality deterioration.

[0020]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a toner which solves the above problems.

More specifically, an object of the present invention is to provide a method for producing a toner, which enables efficient mass production of toner particles synthesized in an aqueous medium without deterioration in quality.

Another object of the present invention is to provide a method for producing a toner capable of obtaining a high quality image without image defects caused by residual volatile components.

[0023]

According to the present invention, a toner synthesized in an aqueous medium is washed and dehydrated, and the volatile component of the obtained wet toner particles is subjected to primary drying, and continuously in a hot air stream. In a manufacturing method having a step of dispersing while being supplied and substantially removing water while being sent in parallel with a hot air stream, and a step of removing other volatile components by a reduced pressure heat treatment accompanied by stirring as secondary drying, A plurality of devices for performing secondary drying are provided for the device for performing primary drying, and toner particles from which moisture has been continuously removed by primary drying are supplied to a first container that can be depressurized and heated. However, when a predetermined amount of toner particles are accumulated in the container, a reduced pressure state is formed in the container, and after the reduced pressure heat treatment is started, the supply from the primary drying to the secondary drying can be reduced and heated. Switch to the second container, and Forming a vacuum state when over particles is accumulated, a method for producing a toner, which comprises starting the heating under reduced pressure.

Particularly, in the present invention, after the reduced pressure heat treatment is started in the second container, the supply from the primary drying to the secondary drying is 2
If a device for performing the next drying is further present, it is put into it and the above-mentioned treatment is repeated, and thereafter, it is continuously put into a container after the reduced pressure heating treatment and discharge, and the above-mentioned treatment is repeated to continuously produce a large amount. The present invention relates to a method for producing a toner, which is capable of being produced.

Furthermore, the present invention provides an apparatus for performing the secondary drying,
When receiving the toner particles from the primary drying and during the secondary drying,
The present invention relates to a method for producing a toner, wherein continuous production is performed without deterioration of physical properties by performing stirring in addition to heating.

[0026]

DETAILED DESCRIPTION OF THE INVENTION As a result of earnest studies, the present inventors
The volatile components of the wet toner particles are continuously dried by first drying, and the toner particles are supplied into a container that can be depressurized and heated to form a depressurized state when a predetermined amount of toner particles are accumulated. Then, the reduced pressure heat treatment is started, and after the first drying, 2
By supplying the supply for the next drying to the other container, similarly forming a reduced pressure state when a predetermined amount of toner particles are accumulated and starting the reduced pressure heat treatment, efficient drying can be performed in a short time. I found that.

In addition, after starting the reduced pressure heat treatment in the second container, the supply from the primary drying to the secondary drying is further added, if there is an apparatus for performing the secondary drying, the above-mentioned is introduced. It has been found that it is possible to efficiently perform mass production by repeating the treatment and thereafter sequentially charging the container after the reduced pressure heating treatment and the discharge, and repeating the above treatment.

Further, since the present inventors perform stirring in addition to heating during receiving the toner from the primary drying and during the secondary drying, it is possible to perform the drying efficiently and without deterioration of the physical properties. I found that there is.

When a vacuum dryer used in a conventional method for producing a polymerized toner is used for drying from the beginning, the size of a copying machine, a printer or the like has been reduced in recent years, and the restrictions on the apparatus have increased due to personalization. Correspondingly, the drying time is too long to provide a toner with less thermal degradation.

Further, when drying is carried out by the airflow dryer alone,
It is possible to disperse the wet colored polymer particles in a high-speed hot air stream and at the same time perform drying while sending them in a parallel flow, and to supply the wet colored polymer particles continuously in the high-speed hot air stream. Although it is a highly efficient dryer, it is difficult to sufficiently remove volatile components because the drying time is instantaneous.

Further, in order to reduce the extension of the drying time caused by the scale difference, which is a problem of vacuum drying, the toner particles heated by air flow drying are kept warm in a hopper or the like, and then vacuum dried to remove volatile components. Although a method for reducing the amount of toner particles has been proposed, if a large amount of toner particles are kept in a hopper as shown in FIG. Could occur. Also, by combining a continuous dryer and a batch dryer, it is possible to form an efficient devolatilization process, but as a system, a continuous or nearly continuous form can be produced efficiently, and production can be performed without quality deterioration. It was a problem to do.

The present invention will be described in more detail below.

In the method for producing a toner of the present invention, it is preferable to preliminarily disintegrate the toner particles after dehydration and washing in order to enhance the dispersion state when the toner particles are sent in parallel with the hot air stream.

Similarly, in order to enhance the dispersion state, the wet toner particles used as a raw material preferably have a water content of 40% or less from the viewpoint of fluidity as a powder. Moreover, 30% or less is more preferable. The term "water content" as used herein refers to a mass-based water content, that is, a ratio of water content to the total mass (sum of dry toner content and water content), and was determined by a weight loss method at 105 ° C.

As an example of a drying step for removing water and other volatile components from the wet colored polymer particles synthesized in the aqueous medium used in the present invention, a loop type pipe as shown in FIG. 1 is used. After the flash dryer,
An apparatus 3 provided with a cyclone for collecting toner particles and provided with a cyclone and a stirring member for performing reduced pressure heat treatment 3
A series of devices and drying systems with directly attached pedestals are included. However, it is not particularly limited, including the number of units.

In this drying system, the powder that has been subjected to primary drying is successively charged into a device for performing a reduced pressure heat treatment, and the charged toner particles are held in a warm state or heated from a heating surface. Since the toner particle layer is made to flow by the stirring member, it is possible to efficiently heat the toner layer, and it is possible to obtain toner particles which do not cause deterioration such as deformation of the toner particles and fusion of the particles.

Further, since there are a plurality of devices for performing the reduced pressure heating process, it is possible to sequentially add the toner particles, which have been subjected to the primary drying, to the vacant device, so that the secondary drying process is awaited. Instead, it is possible to operate continuously or intermittently at will.

Specifically, taking the system shown in FIG. 1 as an example, there are three devices for performing reduced pressure heat treatment of secondary drying after air stream drying of primary drying, and toner particles are supplied to the primary drying. Then, the dried toner particles are collected by the cyclone 7 and continuously supplied to the reduced pressure heat treatment apparatus I.

At this time, in the reduced-pressure heat treatment apparatus I, the stirring member is operated, and heating is also performed from the heat transfer surface.

When the temperature of the toner particles immediately before starting the secondary drying is A and the temperature of the toner particles at the end of drying is B, 35 ° C. <A <60 ° C., 35 ° C. <B <60 ° C., A ≤ B
It is preferable to perform heating so as to satisfy the condition of. A
If B exceeds 60 ° C., which is out of the above range, toner particles may be fused with each other, aggregated, or fused to an apparatus.

The temperature at the start of the reduced pressure heat treatment is 35 ° C.
If it is below, it takes time to raise the temperature to a predetermined temperature, and the drying time is greatly reduced.

Also, if the temperature at the end of drying is 35 ° C. or lower, the drying efficiency is also greatly reduced.

The product temperature of the toner particles during the reduced pressure heat treatment is 2
・ Strict product temperature control is required because drying efficiency is greatly affected even at 3 ℃.

Next, when a predetermined amount of toner particles are accumulated in the reduced pressure heat treatment apparatus I, a reduced pressure state is formed and secondary drying is started. On the other hand, the supply from the primary drying is switched to the reduced pressure heat treatment apparatus II, or the supply is temporarily stopped in order to adjust the treatment amount, and the supply is restarted at a predetermined time, and the reduced pressure heat treatment apparatus II is supplied. Supply.

At this time, similarly to the depressurization heat treatment apparatus I, when the toner is received, the stirring member operates, and the heating is performed at the same temperature as above.

A predetermined amount of toner particles is reduced pressure heat treatment apparatus I.
When the water is accumulated in I, a reduced pressure state is formed and secondary drying is started. After that, switching from the primary drying and the secondary drying (reduced pressure heat treatment apparatus III) are performed in the same manner as the above method, and then the supply of the primary drying is completed and the treatment and discharge of the reduced pressure heat treatment apparatus I are completed. If so, the toner particles are continuously or optionally intermittently supplied to the decompression processing device I.
When the processing is not completed, the supply to the primary drying is temporarily stopped, and the supply is performed when the processing and discharge of the reduced pressure heat treatment apparatus I are completed. After that, they are sequentially put into the vacant apparatus and the same processing is performed.

By this operating method, the primary drying operation can be continuously or arbitrarily intermittently performed, and the production can be performed very efficiently. Further, since the stirring member is operated until the predetermined amount of toner particles are accumulated in the reduced pressure heat treatment apparatus, the toner layer does not cause blocking, and aggregation and fusion of the toner particles can be suppressed. .

Further, in the present invention, since a plurality of secondary drying devices are provided and the same operation is performed, the temperature control equipment, vacuum pump, condenser, etc. can be used in common, and the cost is reduced. It is possible to construct an inexpensive system.

Further, in the present invention, as described above,
In order to further improve the image quality, it is preferable to reduce the residual amount of the polymerizable monomer present in the toner particles to 500 ppm or less.

Furthermore, downsizing of copying machines, printers, etc.,
In order to cope with the increasing restrictions on the device due to personalization,
The residual amount of the polymerizable monomer present in the toner particles is 100
It is preferable to reduce it to ppm or less.

An apparatus for carrying out the heat treatment instantaneously while being fed in parallel to a high-speed hot air stream used as the primary drying of the present invention has, for example, a loop type air current heating tube 5 as shown in FIG. Examples of the heat treatment device include, but are not particularly limited to.

In the primary drying device shown in FIG. 1, first, the air supplied from the discharge blower 1 is compressed air heated to a predetermined temperature in the hot air generator 2 and is discharged at a supersonic speed in the airflow dispersion unit 3. The processed material supplied from the raw material supply device 6 is dispersed and processed instantaneously (0.5 to several tens of seconds) in the loop-type air current heating pipe 5. By setting the airflow outlet 4 inside the loop-type airflow heating pipe 5, particles in an aggregated state are dispersed and particles in a state close to single particles are classified by the Coanda effect. The classified particles are separated from the air flow by the cyclone 7, and the air flow can be discharged to the outside of the system from the exhaust blower 18 via the bag filter 17.

The toner particles collected by the cyclone are directly supplied to the reduced pressure heat treatment device 9.

When a predetermined amount of toner particles are accumulated in one of the reduced pressure heat treatment devices and a reduced pressure state is formed, from the primary drying to 2
The supply for the next drying is switched by the valve 8 and the pressure is supplied to the other reduced pressure heat treatment apparatus.

Further, the measurement of the product temperature at the end of the primary drying can be carried out by arbitrarily introducing it into the sampling port 16.

Further, the coarse particles in the particles discharged from the pipe 5 are separately classified by a classifier and returned to the raw material supply device 6, and only particles in a certain particle size range are supplied to the cyclone 7 to obtain desired toner particles. By obtaining it, classification and heat treatment can be performed continuously.

In addition to the loop type described above, the type of piping of the primary dryer is a straight tube type, in which the inner cylinder is enlarged to increase the residence time, and a vortex motion is applied to the particles to make the horizontal tube bottom. Various types of heat treatment tubes can be used such as a type for preventing deposition, but an airflow heat treatment apparatus having a loop type airflow heating tube 5 as shown in the primary drying section in FIG. 1 is most preferable.

In the present invention, it is preferable to use compressed air heated to 40 to 150 ° C., preferably 60 to 120 ° C. for the heat treatment with a hot air flow. Heating temperature is 40 ℃
If it is lower, the drying efficiency is lowered, and if it is higher than 150 ° C., the toner is fused, which is not preferable.

Specific examples thereof include a flash jet dryer (manufactured by Seishin Enterprise Co., Ltd.) and a flash dryer (manufactured by Hosokawa Micron Corp.).

Next, the reduced-pressure heat treatment apparatus used in the secondary drying of the present invention can be used without particular limitation as long as it is equipped with a stirring member, capable of reducing pressure and heating, and introducing an injection medium. It is possible.

Further, as the injection medium used in the present invention, an inert gas such as nitrogen may be introduced, but in consideration of the drying efficiency and the load of the exhaust equipment, it may be superheated steam or saturated steam. preferable.

For example, a reduced pressure heat treatment apparatus having an embodiment shown in the secondary drying section of FIG. 1 and a schematic side view of FIG. 3 is preferably used.

The secondary drying section of FIG. 1 and the reduced pressure heat treatment apparatus of the embodiment shown in FIG. 2 will be described in detail.

In the reduced pressure heat treatment apparatus shown in the secondary drying section of FIG. 1, toner particles are supplied into the inverse cone-shaped reduced pressure heat treatment container 9 to perform the reduced pressure heat treatment. In the container, a central axis of agitation that can be driven by a drive motor extends in the longitudinal direction of the central axis of the container, and a ribbon blade 10 having a single spiral structure is formed around the central axis of stirring.
Is attached.

By rotating the ribbon blade 10, the toner particles can be repeatedly stirred and dispersed while being lifted from the lower side to the upper side, so that the raw materials in the container can be efficiently stirred and mixed throughout.

A raw material supply port for supplying toner particles and an exhaust path for reducing the pressure inside the container are connected to the upper part of the container with a bag filter 17 and then a condenser 23.

Further, a jacket 11 is provided around the reduced pressure heat treatment container so that the temperature in the container can be appropriately controlled and heat treatment can be performed at a desired temperature. For this reason, a gap is formed between the outer wall of the container and the inner wall of the jacket 11, and although not shown, warm water or steam or cooling water supplied from a warm water tank can be supplied to this gap. At the same time, hot water, steam, and cooling water discharge paths are also provided.

The depressurization in the container is performed by exhausting the volatile components in the container and the injected injection medium from the exhaust port 15 through the bag filter 17 and the condenser 23 by the decompression pump 24.

The supply source of saturated steam / superheated steam into the container is not particularly limited, but in general, it is often supplied from the boiler generator, and the injection medium flow meter 12
After being heated by the injection medium heater 25, it is decompressed to a degree close to the operation decompression degree in the expansion tank, and is uniformly distributed from the lower part of the device into the device through the injection medium dispersion plate 14 for uniformly dispersing the injection medium. Supplied.

When the injection medium is an inert gas such as nitrogen,
Nitrogen supplied from the nitrogen generator passes through the injection medium flow meter and is heated by the injection medium heater 25, and then the injection medium dispersion plate 1 for evenly dispersing nitrogen from the lower part of the apparatus.
It is evenly fed into the apparatus via 4.

The method of changing the injection medium to the depressurized state is not limited to the above-mentioned method, and for example, instead of installing an expansion tank, the diameter of the pipe may be increased.

By uniformly ejecting the injection medium from below, it is possible to prevent toner particles from blocking at the bottom of the apparatus.

The injection medium supplied into the reduced pressure heat treatment container becomes vapor mixed with volatile components from the toner particles, passes through the bag filter, and is condensed / recovered by the next condenser 23. Is discharged from the system through the decompression pump 24.

When the water content of the toner particles is substantially removed, the amount of volatile components generated from the toner particles is very small, and most of them are dominated by the supplied superheated steam / saturated steam.
As a result, most of the above-mentioned condensable injection medium is recovered as water in the condenser 23, so that the decompression pump 2
The amount exhausted in 4 becomes small and the capacity can be small.

However, the non-condensable gas such as nitrogen can hardly be recovered by the condenser 23, so that the vacuum pump 24
Will be overloaded. Considering this point, it is preferable to add superheated steam or saturated steam to the injection medium.

On the other hand, the reduced pressure heat treatment apparatus 19 shown in FIG.
Is provided with a screw-type stirring member 21 connected to a drive motor disposed on the upper part of the container having an inverted conical shape via a drive arm 20. The screw-type stirring member 21 rotates along the inner peripheral surface of the container while rotating. It is configured to turn. Therefore, in the reduced pressure heat treatment apparatus 19 shown in FIG. 3, the toner particles in the container are repeatedly stirred and dispersed while being lifted from the lower part to the upper part, so that the toner particles are efficiently stirred and mixed in the entire container. It The configuration of the other parts of the heat treatment system shown in FIG. 3 is the same as that of the reduced pressure heat treatment system of FIG. 1 except that the supply of water vapor is performed only from the bottom of the apparatus, and therefore the description of this part will be omitted. Omit it.

As the reduced pressure heat treatment apparatus preferably used in the present invention, in addition to the apparatus of the embodiment used in the secondary drying section in FIG. 1 and FIG. 3, specifically, a Nauter mixer (manufactured by Hosokawa Micron Co., Ltd.), a ribo Cone mixer (manufactured by Okawara Seisakusho), PV mixer (manufactured by Shinko Pantec Co., Ltd.), vacuum stir-dryer Inox system (manufactured by Paulec), SV
A mixer (made by Shinko Pantech Co., Ltd.) and the like can be mentioned.

Next, in order to faithfully reproduce smaller latent image dots, the toner according to the present invention is also measured with a smaller particle size, specifically with a Coulter counter, in order to faithfully reproduce smaller latent image dots. Weight average diameter is 4-10 μm
Most preferably, the toner has a number variation coefficient of less than 35%.

If the toner is less than 4 μm, a large amount of untransferred toner is generated on the photosensitive member or the intermediate transfer member due to poor transfer efficiency, which is a cause of fog and uneven transfer of the image due to defective transfer, which is not preferable.

Further, when the weight average diameter of the toner exceeds 10 μm, fusion to the member is apt to occur, and when the number variation coefficient of the toner exceeds 35%, this tendency becomes more serious and becomes a problem.

The toner of the present invention contains at least a resin and a colorant, but may also contain a releasing agent which is a fixing property improving agent, a charge control agent and the like, if necessary. Further, an external additive composed of inorganic fine particles, organic fine particles or the like may be added to the toner particles containing the resin and the colorant as main components.

The toner of the present invention is obtained by emulsion polymerization of a monomer in a suspension polymerization method or in a liquid containing an emulsion of necessary additives.
It can be produced by a method of producing fine polymer particles and then adding an organic solvent, an aggregating agent and the like to associate them.
At the time of association, a method of preparing by mixing with a dispersion liquid such as a release agent or a colorant necessary for the constitution of the toner to allow association, or dispersing a toner constituent component such as a release agent or a colorant in a monomer Then, a method of emulsion polymerization may be used. Here, the association means that a plurality of resin particles and colorant particles are fused.

The aqueous medium as used in the present invention means a medium containing at least 50% by mass of water.

The production method of the suspension polymerization method is not particularly limited, but the following production methods can be mentioned.

That is, various constituent materials such as a colorant and, if necessary, a releasing agent, a charge control agent, and a polymerization initiator are added to the polymerizable monomer, and a homogenizer, a sand mill, a sand grinder, and an ultrasonic dispersion are added. Various constituent materials are dissolved or dispersed in the polymerizable monomer by a machine or the like. The polymerizable monomer in which these various constituent materials are dissolved or dispersed is dispersed in an oil droplet having a desired size as a toner in a water-based medium containing a dispersion stabilizer by using a homomixer or a homogenizer. After that, transfer to a reactor having a stirring mechanism,
The polymerization reaction proceeds by heating. After completion of the reaction, the dispersion stabilizer is removed, filtered, washed, and dried to prepare the toner of the present invention.

Further, as a method for producing the toner of the present invention, a method of fusing resin particles in an aqueous medium and adjusting the resin particles can be mentioned. This method is not particularly limited, but for example, JP-A-5-265252, JP-A-6-329947, and JP-A-9-159.
The method shown in Japanese Patent Publication No. 04 can be mentioned. That is, dispersed particles of resin particles and constituent materials such as a colorant, or a method of associating a plurality of fine particles composed of a resin and a colorant, etc., in particular, after dispersing them in an aqueous medium using an emulsifier, At the same time as salting out by adding a flocculant having a flocculation concentration or higher, heat-fusing at a temperature not lower than the glass transition temperature of the formed polymer itself, and heating and drying the particles in a fluid state in a water-containing state, the present invention Toner can be formed. Here, an organic solvent infinitely soluble in water may be added at the same time as the coagulant.

In the present invention, a so-called seed polymerization method, in which a monomer is further adsorbed on the polymer particles once obtained and then polymerized by using a polymerization initiator, can be suitably used in the present invention.

Examples of the polymerizable monomer that can be used in the above polymerized toner include styrene-based monomers such as styrene, o (m-, p-)-methylstyrene, and m (p-)-ethylstyrene; (meth). Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, (meth) acrylic (Meth) acrylate monomers such as behenyl acid, 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate; butadiene, isoprene, cyclohexene, (meth) Vinyl monomers such as acrylonitrile and acrylic acid amide are preferably used. In addition, two or more kinds may be preferably used in combination, if necessary.

In the present invention, it is particularly preferable to add a polar resin in addition to the outer shell resin in order to encapsulate the low softening point substance in the outer shell resin. As the polar resin used in the present invention, a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin, and an epoxy resin are preferably used. It is particularly preferable that the polar resin does not contain an unsaturated group capable of reacting with the shell resin or the monomer in the molecule. In the case of containing a polar resin having an unsaturated group, a crosslinking reaction occurs with a monomer forming the outer shell resin layer, resulting in an extremely high molecular weight as a full-color toner, which is disadvantageous for color mixing of four-color toner, which is not preferable. .

As the low softening point substance used in the present invention, a compound having a main component maximum peak value measured according to ASTM D3418-8 of 40 to 90 ° C. is preferable. When the maximum peak is less than 40 ° C., the self-aggregating force of the low softening point substance becomes weak, and as a result, the high temperature offset resistance becomes weak, which is not preferable for a full color toner. On the other hand, when the maximum peak exceeds 90 ° C., the fixing temperature becomes high, and it becomes difficult to appropriately smooth the surface of the fixed image, which is not preferable from the viewpoint of mixing property. Further, when a toner is obtained by a direct polymerization method, the temperature of the maximum peak value is high because granulation and polymerization are carried out in an aqueous system, and a low softening point substance mainly precipitates during granulation, which hinders the suspension system. Therefore, it is not preferable. Specifically, paraffin wax, polyolefin wax, Fischer-Ropish wax, amide wax, higher fatty acid, ester wax and derivatives thereof, or graft / block compounds thereof can be used.

As the colorant used in the present invention, carbon black, a magnetic material, or a yellow / magenta / cyan colorant shown below, which is toned black, is used.

As the yellow colorant, condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
Compounds represented by azo metal complexes, methine compounds and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 109, 110,
111, 128, 129, 147, 168 and the like are preferably used.

As the magenta colorant, a condensed azo compound, a diketopyrrolopyrrole compound, an anthraquinone, a quinacridone compound, a basic dye lake compound, a naphthol compound, a benzimidazolone compound, a thioindigo compound and a perylene compound are used. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8: 2, 48: 3, 48: 4, 57: 1, 81: 1, 1
22, 144, 146, 166, 169, 177, 18
4, 185, 202, 206, 220, 221, 254
Is particularly preferable.

As the cyan colorant, a copper phthalocyanine compound and its derivative, an anthraquinone compound, a basic dye lake compound and the like can be used. Specifically, C.I. I.
Pigment Blue 1, 7, 15, 15: 1, 15: 2,
15: 3, 15: 4, 60, 62, 66 and the like can be used particularly preferably.

These colorants may be used alone or in a mixture, and may be used in the form of a solid solution. The colorant of the present invention is selected in terms of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in the toner. The amount of the colorant added is 1 to 20 parts by mass based on 100 parts by mass of the resin.

When a magnetic substance is used as the black colorant, unlike the other colorants, the amount is 40% with respect to 100 parts by mass of the resin.
It is used by adding ~ 150 parts by mass.

The charge control agent used in the present invention includes:
Known charge agents can be used, but a charge control agent that is colorless and has a high toner charging speed and that can stably maintain a constant charge amount is preferable. Further, when the direct polymerization method is used in the present invention, a charge control agent having no polymerization inhibitory property and having no solubilized product in an aqueous system is particularly preferable. Specific compounds include:
As a negative system, metal compounds of salicylic acid, naphthoic acid, dicarboxylic acid, sulfonic acid, polymer compounds having a carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds, currys arenes, etc. can be used. A quaternary ammonium salt, a polymer type compound having the quaternary ammonium salt in its side chain, a guanidine compound, an imidazole compound and the like are preferably used. The charge control agent is resin 10
0.5 to 10 parts by mass is preferable with respect to 0 parts by mass. However, the addition of a charge control agent in the present invention is not essential, in the case of using the two-component developing method, utilizing the triboelectric charging with the carrier, even in the case of using the non-magnetic one-component blade coating developing method. By positively utilizing the triboelectric charging with the member or the sleeve member, it is not always necessary to include the charge control agent in the toner.

Examples of the polymerization initiator that can be used in the polymerized toner according to the present invention include 2,2'-azobis- (2
4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-
Azo-based or diazo-based polymerization initiators such as methoxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl A peroxide type polymerization initiator such as peroxide is used. The amount of the polymerization initiator added varies depending on the intended degree of polymerization, but it is generally used in an amount of 0.5 to 20% by mass based on the monomer. Although the type of the polymerization initiator varies slightly depending on the polymerization method, it may be used alone or in combination with reference to the 10-hour half-life temperature.

In order to control the degree of polymerization, known cross-linking agents, chain transfer agents, polymerization inhibitors and the like can be further added and used.

In the polymerized toner according to the present invention, as the dispersant used when suspension polymerization using a dispersant is particularly used, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate can be used as the inorganic compound. , Calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina and the like. As organic compounds, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose,
Polyacrylic acid and its salt, starch, etc. can be used by dispersing in an aqueous phase. These stabilizers are polymerizable monomers 10
It is preferable to use 0.2 to 20 parts by mass with respect to 0 parts by mass.

When an inorganic compound is used among these stabilizers, a commercially available one may be used as it is, but the inorganic compound may be formed in a dispersion medium in order to obtain fine particles. For example, in the case of tricalcium phosphate, it is advisable to mix the sodium phosphate aqueous solution and the calcium chloride aqueous solution under high stirring.

Further, for fine dispersion of these stabilizers, 0.001 to 0.1 part by mass of a surfactant may be used. This is for promoting the intended action of the above dispersion stabilizer, and specific examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate,
Examples thereof include sodium oleate, sodium laurate, potassium stearate, calcium oleate and the like.

In the toner manufacturing method of the present invention, the toner can be specifically manufactured by the following manufacturing method.

That is, a releasing agent, a colorant, a charge control agent, a polymerization initiator and other additives made of a low softening point substance are added to the polymerizable monomer and uniformly dissolved by a homogenizer, an ultrasonic disperser or the like. Alternatively, the dispersed monomer system is dispersed in an aqueous phase containing a dispersion stabilizer by a usual stirrer, a clear mix, a homomixer, a homogenizer or the like. Preferably, the stirring speed and time are adjusted so that the monomer droplets have the desired toner particle size, and granulation is performed. After that, by the action of the dispersion stabilizer, the particle state is maintained,
In addition, the stirring may be performed to such an extent that sedimentation of the particles is prevented.
The polymerization temperature is preferably set to 40 ° C. or higher, generally 50 to 90 ° C. for polymerization. In addition, the temperature may be raised in the latter half of the polymerization reaction, and further in the latter half of the reaction or the end of the reaction in order to remove unreacted polymerizable monomers and by-products that may cause odor during toner fixing. The aqueous medium may be partially distilled off later. After the reaction is completed, the produced toner particles are collected by washing and filtering, and dried by the drying method of the present invention.
In the suspension polymerization method, it is usually preferable to use 300 to 3000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the monomer system.

In the present invention, the Tg of the toner particles thus obtained is adjusted to 40 to 75 ° C. When the temperature is lower than 40 ° C., problems occur in storage stability of the toner and durability stability of the developer, and when the temperature is higher than 75 ° C., the fixing point is increased. However, the color reproducibility is poor, and the transparency of the OHP image is significantly reduced, which is not preferable in terms of high image quality.

Further, the manufacturing method of the present invention can be applied not only to the toner but also to the binder resin for the toner. The binder resin for a toner in a wet state obtained by various polymerization methods requires a step of removing water, residual polymerizable monomers and other volatile components, like the toner particles obtained by the polymerization method. , As the volatile matter removal step,
The reduced pressure heat treatment described above can be used.

Examples of the binder resin for the toner used in the present invention include vinyl resins, polyester resins, copolymers of vinyl monomers and polyester monomers, etc., but are not particularly limited.

The method of measuring each physical property value used in the present invention will be described below.

1. Measurement Method of Toner Particles Tg In the present invention, measurement was performed by the following method using a differential thermal analysis measurement device (DSC measurement device) and DSC-7 (manufactured by Perkin Elmer Co., Ltd.). First, the measurement sample is 5 to 20 m.
Precisely weigh g, preferably 10 mg. Then, this is put in an aluminum pan, and an empty aluminum pan is used as a reference, and the temperature rising rate is 10 ° C./min. At room temperature and humidity. As a result, in this temperature rising process, the intersection point between the line at the midpoint of the baseline and the differential thermal curve before and after the endothermic peak of the main peak in the temperature range of 40 to 100 ° C appears in the present invention. The glass transition temperature is Tg.

2. Method of Measuring Moisture Content The moisture content of the toner of the present invention was measured by a weight loss method at 105 ° C. using a MA40 electronic moisture meter (manufactured by Sartorius).

3. Measurement of residual amount of polymerizable monomer and other organic volatile substances remaining in toner particles Quantification of residual amount of polymerizable monomer and other organic volatile substances remaining in toner particles is 0.3 g of toner. Was dissolved in 10 g of acetone, subjected to an ultrasonic shaker for 30 minutes, allowed to stand for 1 day, and then filtered through a 0.5 μm filter. It was measured by a calibration curve method.

G. C. Condition measuring device: HEWLETT PACKARD HP 6
890 series capillary column: (25m × 0.2mm, HP-IN
NOWAX, film thickness: 0.4 μm) Detector: FID He flow rate 25 ml / min Injection temperature: 200 ° C. Detector temperature: 250 ° C. Column temperature: Temperature rise from 50 ° C. to 10 ° C./min for 15 minutes Implanted sample amount: 2 μl

4. Measuring Method of Toner Particle Size Distribution Here, the particle size distribution can be measured by various methods, but in the present invention, it was measured using a Coulter counter.

As the measuring device, Coulter Counter TA-II type or Coulter Multisizer II (manufactured by Coulter) is used. As the electrolytic solution, about 1% NaCl aqueous solution is prepared using first-grade sodium chloride. For example, ISOTON-II (manufactured by Coulter Scientific Japan Co.) can be used. As a measuring method,
As a dispersant in 100 to 150 ml of the electrolytic aqueous solution,
Add 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, and further add a measurement sample of 2 to 20 m.
Add g. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the volume and number of the toner is measured by using the measuring device with a 100 μm aperture as an aperture to measure the volume distribution and the number. And the distribution was calculated. Then, the weight-based weight average particle diameter (D4) (the median value of each channel is used as a representative value for each channel) determined from the volume distribution according to the present invention was determined. The particle size distribution of toner particles can be measured by various methods, but in the present invention, it was measured using a Coulter counter.

[0115]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 450 parts by mass of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution was added to 710 parts by mass of ion-exchanged water, and the mixture was heated to 60 ° C. and then Clearmix (M.
(Technique Co., Ltd.) was used and stirred at 3,500 rpm. To this, 68 parts by mass of 1.0 mol / liter-CaCl ₂ aqueous solution was added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

On the other hand, the dispersoid system was: styrene monomer 175 parts by mass n-butyl acrylate 25 parts by mass C.I. I. Pigment Blue 15: 3 10 parts by mass, saturated polyester 20 parts by mass, metal salicylate compound 3 parts by mass, ester wax 30 parts by mass. I. Pigment Blue 15: 3,
A metal salicylate compound and 100 parts by mass of a styrene monomer were dispersed for 3 hours using an attritor (Mitsui Miike Kakoki Co., Ltd.) to obtain a colorant dispersion liquid. Next, the rest of the above formulation was added to the colorant dispersion, heated to 60 ° C., and dissolved and mixed for 30 minutes. 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile), which is a polymerization initiator, was dissolved in this to prepare a polymerizable monomer composition.

The above polymerizable monomer composition was put into the above aqueous dispersion medium and granulated for 15 minutes while maintaining the rotation speed. After that, the stirrer was changed from the high-speed stirrer to the propeller stirrer, the internal temperature was raised to 80 ° C, and the polymerization was performed at 50 rpm for 10 minutes.
I continued for hours. Next, the internal temperature is 80 ° C and the internal pressure is 4
Distillation was carried out for 4 hours under the condition of 7.3 kPa. After the distillation is completed, the slurry is cooled, diluted hydrochloric acid is added, and Ca ₃ (P
After the O ₄ ) ₂ was dissolved, it was filtered, washed with water, and then crushed to obtain wet colored polymer particles (toner particles) having a water content of 23% and a weight average diameter of 7.9 μm.

At this point, the amount of the polymerizable monomer remaining in the toner particles was 750 ppm.

Volatile components were removed from the obtained wet toner particles by using a system in which primary drying was carried out by air flow drying for one unit and three reduced pressure heat treatment devices were connected directly.

The air flow drying of the primary drying is performed with a pipe diameter of 0.1.
Drying was performed using the apparatus of the embodiment shown in the primary drying part of FIG. Further, the reduced pressure heat treatment apparatus has a capacity of 10
Drying was performed using a 0 L apparatus.

Drying conditions are as follows: primary drying, blowing temperature: 90 ° C., blowing air amount: 10 m ³ / min, raw material supply amount: 40 kg / hr, secondary drying, when receiving toner, stirring speed: 26 rpm, heating temperature: 50 ° C. During vacuum drying Stirring speed: 26 rpm Heating temperature: 50 ° C. Superheated steam input amount: 2.5 m ³ / hr Treatment was carried out at a superheated steam temperature: 50 ° C.

The primary drying time (= the time for which a predetermined amount of toner particles is accumulated in the reduced pressure heat treatment device) is about 45 min, and
The temperature of the toner particles before the completion of the secondary drying and the start of the secondary drying was 46 ° C, and the average temperature of the toner layer in the apparatus at the start of the secondary drying was 48 ° C.

After that, the same treatment was repeated by successively introducing the toner into a reduced pressure heat treatment apparatus containing no toner layer.

In the first and fourth treatments of the reduced pressure heat treatment apparatus I, the degree of reduced pressure during the secondary drying was 3.2 kPa on average in both cases. The water content after drying for 5 hours was 0.2%, the amount of the remaining polymerizable monomer was 30 ppm, and the temperature of the toner particles at the end of drying was 49 ° C.
Met.

By using this drying system,
A treatment of about 360 kg could be performed in a treatment time of about 24 hours.

Further, in this drying system, since the three reduced pressure heat treatment devices are operated under the same conditions, the temperature control equipment
It became possible to share the vacuum pump and condenser, etc., and it was possible to significantly reduce capital investment. Further, with this drying system configuration, the number of reduced-pressure heat treatment devices is three times, but the number of primary drying devices is one, and the capacity is three times that of Comparative Example 1 described later. Could be achieved.

Further, to 100 parts by mass of the toner obtained by the first and fourth treatments, 1.5 parts by mass of hydrophobic silica having a specific surface area of 200 m ² / g by the BET method is externally added to the developer. And

Using this developer and a modified LBP2040 (manufactured by Canon), images were printed on 3000 sheets in an environment of 30 ° C./80% RH, and vertical streaks were observed before and after durability. An excellent image with no image was obtained. The evaluation results are shown in Table 1.

<Second Embodiment> The conditions for the secondary drying are as follows: Secondary drying At the time of receiving toner Stirring speed: 26 rpm Heating temperature: 60 ° C. Vacuum drying At stirring speed: 26 rpm Heating temperature: 60 ° C. Superheated steam input amount : 2.5 m ³ / hr Superheated steam temperature: The same drying system and drying conditions as in Example 1 were used except that the temperature was 60 ° C.

The primary drying time (= the time required for a predetermined amount of toner particles to accumulate in the reduced pressure heat treatment device) is about 45 minutes, and
The temperature of the toner particles before the completion of the secondary drying and the start of the secondary drying was 46 ° C, and the average temperature of the toner layer in the apparatus at the start of the secondary drying was 53 ° C.

After that, the same treatments were repeated by sequentially introducing the toners into a reduced pressure heat treatment apparatus containing no toner layer.

The degree of pressure reduction during the secondary drying is 3.2 kPa on average.
Met. After drying for 5 hours, the water content was 0.2%, the amount of the remaining polymerizable monomer was 20 ppm, and the toner particle temperature was 58 ° C.

By using this drying system,
A treatment of about 360 kg could be performed in a treatment time of about 24 hours.

However, the obtained toner particles were slightly mixed with a tendency to aggregate.

The toner thus obtained was used as a developer in the same manner as in Example 1 below, and the image formation was evaluated in the same manner as in Example 1. As a result, vertical streaks were generated before and after the durability test. There wasn't. However, although there is no problem in practical use,
The image was slightly shaky in the latter half of the endurance. Table 1 shows the evaluation results
Shown in.

Example 3 Except that the depressurization heating apparatus is treated by using the apparatus having a capacity of 100 L shown in FIG.
The treatment was performed under the apparatus and apparatus configuration and drying conditions described in Example 1.

The primary drying time is about 45 minutes, the temperature of the toner particles before the secondary drying is 46 ° C.
And the average temperature of the toner layer in the apparatus at the start of secondary drying was 47 ° C.

The degree of pressure reduction during the secondary drying is 3.2 kPa on average.
Met. The water content after drying for 5 hours is 0.
25%, the amount of the remaining polymerizable monomer was 40 ppm, and the product temperature of the toner particles was 48 ° C.

Further, about 360 kg of treatment could be carried out with the treatment amount of about 24 hr.

The toner thus obtained was used as a developer in the same manner as in Example 1 below, and the same image evaluation as in Example 1 was carried out. The same results as in Example 1 were obtained. Was given.

The evaluation results are shown in Table 1.

Example 4 The operation was performed under the drying system and the drying conditions described in Example 1 except that the injection medium to be charged was nitrogen.

The primary drying time is about 45 minutes, the temperature of the toner particles before the secondary drying is 46 ° C.
And the average temperature of the toner layer in the apparatus at the start of secondary drying was 47 ° C.

The degree of pressure reduction during the secondary drying is 3.0 kPa on average.
Met. The water content after drying for 5 hours is 0.
3%, the amount of the remaining polymerizable monomer was 100 ppm, and the product temperature of the toner particles was 47 ° C.

Further, about 360 kg of treatment could be performed with the treatment amount of about 24 hr.

The toner thus obtained was used as a developer in the same manner as in Example 1 below, and the same image development evaluation as in Example 1 was carried out. There wasn't. However, although there was no problem in practical use, the image was slightly shaky in the latter half of the endurance.

The evaluation results are shown in Table 1.

<Comparative Example 1> After air stream drying of primary drying,
After the toner particles are heated or kept warm by a hopper having a heating or keeping function, the toner particles are supplied to a reduced pressure heat treatment apparatus which is a secondary drying, and the drying is started using the drying system shown in FIG. .

The primary drying time is about 45 minutes, and the temperature of the toner particles before entering the hopper is 46 ° C. after the primary drying is completed.
The average temperature of the toner layer in the apparatus at the start of secondary drying was 46 ° C.

The degree of pressure reduction during the secondary drying is 3.2 kPa on average.
Met. The water content after drying for 5 hours is 0.
3%, the amount of the remaining polymerizable monomer was 40 ppm, and the product temperature of the toner particles was 48 ° C.

Further, about 120 kg of treatment could be performed with the treatment amount of about 24 hr.

The toner thus obtained was used as a developer in the same manner as in Example 1 below, and was subjected to the same image formation evaluation as in Example 1. As a result, vertical streaks were generated before and after the durability test. There wasn't. However, from the beginning of endurance, the image began to grumble,
In the latter half of the endurance, it reached a level that was difficult to put into practical use. The evaluation results are shown in Table 1.

Further, since there was blocking in the hopper, discharge from the hopper to the reduced pressure heat treatment apparatus could not be performed smoothly.

<Comparative Example 2> The drying conditions during the secondary drying are as follows: Secondary drying When receiving toner Stirring speed: 26 rpm Heating temperature: 70 ° C. Vacuum drying When stirring speed: 26 rpm Heating temperature: 70 ° C. Superheated steam input Amount: 2.5 m ³ / hr Superheated steam temperature: The same drying system and drying conditions as in Example 1 were used except that the temperature was 70 ° C.

The primary drying time (= the time for which a predetermined amount of toner particles is accumulated in the reduced pressure heat treatment apparatus) is about 45 minutes and is 1
The temperature of the toner particles before the completion of the secondary drying and the start of the secondary drying was 46 ° C., and the average temperature of the toner layer in the apparatus at the start of the secondary drying was 58 ° C.

The degree of reduced pressure during the secondary drying was 3.3 kPa on average. The water content after drying for 5 hours is 0.1.
5%, the amount of the remaining polymerizable monomer was 15 ppm, and the product temperature of the toner particles was 67 ° C.

Further, the treatment amount of about 360 kg could be achieved with the treatment amount of about 24 hr.

However, the obtained toner was slightly agglomerated, and fusion was observed in the apparatus.

The toner thus obtained was used as a developer in the same manner as in Example 1 below, and the same image development evaluation as in Example 1 was carried out. A streak was generated and streaks were observed. The vertical streaks increased with the endurance and became rough, and in the latter half of the endurance, the vertical streaks and the entire face were rough. The evaluation results are shown in Table 1.

Reference Example 1 Moisture content 2 obtained after crushing
3%, a weight average diameter of 7.9 μm, a water content of 23%, and a wet-colored polymer particle (toner particle) having a residual amount of the polymerizable monomer of 750 ppm is subjected to primary drying by one device, 2
The treatment was performed using a drying system having one apparatus for performing the subsequent drying (a form in which the reduced pressure heat treatment apparatuses II and III are omitted from the drying system shown in FIG. 1).

The primary drying is supplied to the secondary drying, and when a predetermined amount of toner particles are accumulated, a reduced pressure state is formed to start the secondary drying, while the primary drying is performed by the secondary drying. While it was stopped, it was stopped, and when the drying and discharging were completed, the primary drying was started again, and the secondary drying was supplied. After that, the above process was repeated.

The drying conditions are as follows: primary drying, blowing temperature: 90 ° C., blowing air amount: 10 m ³ / min, raw material supply amount: 40 kg / hr, secondary drying, when receiving toner, stirring rotation speed: 26 rpm, heating temperature: 50 ℃ Vacuum drying stirring rotation speed: 26 rpm Heating temperature: 50 ° C. Superheated steam input amount: 2.5 m ³ / hr Superheated steam temperature: 50 ° C.

The primary drying time (= the time for which a predetermined amount of toner particles is accumulated in the reduced pressure heat treatment device) is about 45 minutes, and
The temperature of the toner particles before the completion of the secondary drying and the start of the secondary drying was 46 ° C, and the average temperature of the toner layer in the apparatus at the start of the secondary drying was 48 ° C.

The degree of reduced pressure during the secondary drying was 3.2 kPa on average. The water content after drying for 5 hours was 0.2%, the amount of the remaining polymerizable monomer was 20 ppm, and the product temperature of the toner particles was 48.5 ° C.

However, in this drying system, the processing time was about 24 hours and only about 120 kg could be processed.

The toner thus obtained was used as a developer in the same manner as in Example 1 below, and the same image evaluation as in Example 1 was carried out. The same results as in Example 1 were obtained. Was given.

The evaluation results are shown in Table 1.

The criteria for determining the vertical stripes are as follows. A: No vertical streak has occurred. B: Several vertical stripes occurred. C: A large number of vertical stripes were generated.

The image quality judgment criteria are as follows. A: Very good. B: Although it is slightly shaky from the latter half of the endurance, there is no problem in practical use. C: It is difficult to put it into practical use because it has been rough since the beginning of durability. D: Practically impractical due to severe roughness.

[0171]

[Table 1]

[0172]

As described above, according to the present invention,
To provide a toner manufacturing method capable of mass-producing toner particles synthesized in an aqueous medium without deterioration in quality and efficiently, and in a system in which capital investment is suppressed by a process that eliminates waste. You can

Further, it is possible to provide a method for producing a toner capable of obtaining a high quality image free from image defects caused by residual volatile components.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a drying system used in the present invention for continuously processing toner.

FIG. 2 is a schematic view showing an example of an apparatus for heating toner particles under reduced pressure, which is used in the present invention.

FIG. 3 is an example of a drying system in which after the air stream drying which is the primary drying, the temperature is kept or / and the temperature is raised by the hopper, and the reduced pressure heat treatment is performed in that state.

[Explanation of symbols]

1 discharge blower 2 hot air generator 3 Airflow dispersion unit 4 Air flow outlet 5 loop type air flow heating tube 6 Raw material supply device 7 cyclone 8 valves 9 Reduced pressure heat treatment device (ribbon blade) 10 stirring blades 11 jacket 12 Flowmeter 13 Thermometer 14 Injection medium dispersion board 15 exhaust port 16 sampling port 17 Bug Filter 18 Exhaust blower 19 Reduced pressure heat treatment device (screw stirring blade) 20 drive arm 21 screw stirring blade 22 hopper 23 condenser 24 Decompression pump 25 Injection medium heater

Continued front page    (72) Inventor Minoru Omura             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Satoshi Iki             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F-term (reference) 2H005 AB06 EA03 EA10

Claims (11)

[Claims] 1. A toner synthesized in an aqueous medium is washed and dehydrated, and the volatile components of the obtained wet toner particles are subjected to primary drying to be dispersed while being continuously supplied to a hot air stream. In the manufacturing method having a step of substantially removing water while sending in parallel flow, and a step of removing other volatile components by a reduced pressure heat treatment accompanied by stirring as a secondary drying, an apparatus for performing the primary drying is used. On the other hand, a plurality of devices for performing secondary drying are provided, and toner particles from which water has been continuously removed by primary drying are supplied to a first container that can be depressurized and heated,
When a predetermined amount of toner particles are accumulated in the container, a reduced pressure state is formed in the container, and after the reduced pressure heat treatment is started,
The supply from the primary drying to the secondary drying is switched to a second container capable of reducing pressure and heating, and when a predetermined amount of toner particles are accumulated, a reduced pressure state is formed and the reduced pressure heating process is started. Method for producing toner. 2. After starting the reduced-pressure heat treatment in the second container, the supply from the primary drying to the secondary drying is further added to a device for performing the secondary drying, if any. 2. The method for producing a toner according to claim 1, wherein the above process is repeated, and thereafter, the above process is repeated by sequentially charging the container in which the reduced pressure heating process and the discharging have been completed. 3. The method for producing a toner according to claim 1, wherein the apparatus for performing the secondary drying also performs heating when receiving the toner particles from the primary drying. 4. The apparatus for performing the secondary drying is provided with a stirring member, and the stirring member is operated when receiving the toner particles from the primary drying and during heat treatment under reduced pressure. Item 4. The method for producing a toner according to any one of Items 1 to 3. 5. The method for producing a toner according to claim 1, wherein the volatile component contains at least an unreacted polymerizable monomer. 6. The residual amount of the unreacted polymerizable monomer is 10
The method for producing a toner according to claim 5, wherein the heat treatment is performed until it becomes 0 ppm or less. 7. The temperature of the toner particles when the toner is received in a depressurizable container and a predetermined amount of toner particles are accumulated and immediately before starting secondary drying is A, and the temperature of the toner particles at the end of drying is B. The toner manufacturing method according to claim 1, wherein 35 ° C. <A <60 ° C., 35 ° C. <B <60 ° C., and A ≦ B. 8. The method for producing a toner according to claim 1, wherein the wet toner particles obtained after washing and dehydration have a water content of less than 40%. 9. The method for producing a toner according to claim 1, wherein the wet toner particles obtained after washing and dehydration have a water content of less than 30%. 10. The method for producing a toner according to claim 1, wherein the heating treatment under reduced pressure is performed while introducing the injection medium into the container. 11. The method for producing a toner according to claim 10, wherein the injection medium is superheated steam or saturated steam.