JP2003167379A - Method for manufacturing toner particles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing toner particles by which all of volatile components present in toner particles obtained by polymerization are uniformly diminished in a short period of time and not compacted, not aggregated and/or thermally and mechanically not deteriorated toner particles are obtained. <P>SOLUTION: In the method for manufacturing toner particles, toner particles formed in an aqueous medium are washed and dewatered and the resulting wet toner particles are supplied to a vessel and heat-treated under reduced pressure while charging into the vessel an injection medium selected from the group comprising saturated steam, superheated steam and highly damp air whose enthalpy is ≥2,500 kJ/kg (dry air) at a temperature below the glass transition temperature Tg of the toner particles, it is characterized in reducing the total amount of organic volatile components (expressed in terms of toluene) to ≤500 ppm on the basis of the mass of the toner particles in analysis of organic volatile components at 150°C heating temperature of toner particles by the head space method. <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 producing toner particles, and to an improvement in a technique for removing volatile components in toner particles obtained by a polymerization 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 large number of methods are known, and generally a large number of methods are known. Form an electrical latent image on the surface, then develop the latent image with toner, transfer the toner image to a transfer material such as paper, if necessary, and then fix it by heating, pressure, solvent vapor or the like to copy. Get things. Further, as a method of developing with a toner or a method of fixing a toner image, various methods have been conventionally proposed, and a method suitable for each image forming process is 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, multifunctionalization of toner itself has been required 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.

Furthermore, when using a dye, a pigment, a polymerization initiator, a charge control agent, a magnetic substance, etc., by-products derived from those substances are also generated. Further, with the multi-functionalization and multi-product variety of the toner, these internal additive components are also diversified, so that various by-products may be generated. In some cases, the total amount of various by-products may exceed the amount of unreacted polymerizable monomer.

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, the image quality is deteriorated, and blocking resistance is increased. 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 and other by-products volatilize during fixing to give off a bad odor.

Further, downsizing of copying machines, printers, etc.,
As personalization increases, the restrictions on the device increase, the load on the above problems increases, and the interest in the environment also increases, and it is required to reduce the total amount of volatile components derived from toner particles generated in fixing and the like. Therefore, it is preferable to reduce the total amount of volatile components present in the toner particles to 500 ppm or less.

As a method for reducing the total amount of volatile components in the toner particles to a further small amount, the toner binder resin is not dissolved but the polymerizable monomer and / or other by-products are dissolved. The method of washing with an organic solvent described above; the method of washing with an acid or alkali; the solvent component that does not dissolve the foaming agent or the polymer is added to the polymer system, and the obtained toner particles are made porous to reduce the volatilization area of the volatile components inside. A sieving method; and a method of removing volatile components under dry conditions can be mentioned, but it is difficult to elute the toner constituent components due to the deterioration of the toner capsule property and it is difficult to select the solvent such as the residual property of the solvent.
The most preferable method is to reduce the total amount of polymerizable monomers and other by-products, that is, volatile components under dry conditions.

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

Japanese Unexamined Patent Publication (Kokai) No. 08-160662 proposes a method of vacuum-drying toner particles. This drying method has an advantage of being able to dry an object to be dried at a low temperature, but the apparatus is in a reduced pressure state. Therefore, since the gas phase stays and the force for diffusing the volatile component is significantly reduced, it takes a very long drying time to further remove the volatile components after removing the water by evaporation. I will end up.

Further, JP-A-10-207122 proposes a method of vacuum-drying toner particles while injecting gas.

However, as described in the specification of this publication, when an inert gas or the like is used as the gas to be injected, the effect of the carrier gas is exerted and the volatile components are not retained as compared with the case where the gas is simply vacuum dried. Drying efficiency is improved in that respect, but with a dry gas such as an inert gas, the amount of heat that the gas itself can have is extremely small, so heat is taken from the heated toner particles, and the drying efficiency is reduced. To do.

Therefore, since the drying time is extended and the thermal history applied to the toner particles is prolonged, the particles are deformed and the particles are fused to each other, resulting in lumps and deterioration of image characteristics. .

When the temperature of the injected gas is not controlled by heating or the like, the gas whose temperature has been lowered due to adiabatic expansion directly enters in the path for feeding the gas, so that heat is remarkably taken from the toner particles. However, the drying efficiency is further reduced.

Further, in this gas, the resistance due to diffusion which hinders evaporation (although it is smaller than that when no carrier gas is used) is the main factor that determines the drying rate. In order to improve this, for example, when the flow rate of the gas is increased, it is necessary to increase the capacity of the exhaust equipment (mainly a vacuum pump) accordingly, resulting in a large production cost. This is all the more so when it comes to mass production.

Further, when the toner particles are dried in a vacuum state, the toner particle layer is compacted and agglomerated due to the vacuum. For this reason, it has been conventionally performed to overcome the force of compaction / aggregation of the toner particle layer by using the stirring member, that is, to apply the force of releasing the toner particle layer.

However, if there is a portion where the fluidization of the toner particle layer is retained due to poor stirring, there is a high possibility that the portion will be compacted / aggregated, and an insufficiently dried product is produced and at the same time the image is formed. There was a problem of causing deterioration. Therefore, it may be necessary to separately provide a step of crushing the compacted and agglomerated toner particles after drying, which is disadvantageous in terms of cost.

On the other hand, if the toner is agitated excessively, the toner particles will be thermally and mechanically damaged, and the toner particles, which also cause the image deterioration, are generated.

As mentioned above, this drying method is efficient.
Many problems remain in terms of quality and cost, and it has been a problem for many engineers to solve them.

[0024]

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

More specifically, the object of the present invention is to reduce all volatile components present in the toner particles obtained by the polymerization method uniformly and in a short time, while at the same time consolidating / aggregating and / or thermally / mechanically. It is an object of the present invention to provide a method for producing toner particles, which is capable of obtaining toner particles that have not been physically deteriorated.

Another object of the present invention is to provide a method for producing toner particles, which is capable of obtaining a high quality image free from image defects caused by residual volatile components and compacted / aggregated toner particles.

In addition, an object of the present invention is to reduce the energy and cost required for removing the volatile component.

[0028]

According to the present invention, toner particles produced in an aqueous dispersion medium are washed and dehydrated, and the obtained wet toner particles are supplied to a container, and the glass transition of the toner particles is performed. By performing a reduced pressure heat treatment while introducing an injection medium selected from the group consisting of saturated steam, superheated steam, or high-humidity air having an enthalpy of 2500 kJ / kg (dry air) or more at a temperature lower than the temperature Tg into the container, Heating temperature of toner particles by headspace method 1
In the organic volatile component analysis at 50 ° C., the total amount of organic volatile components in terms of toluene based on the toner particle mass is 5
The present invention relates to a method for producing toner particles, which is characterized in that the content is set to 00 ppm or less.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of intensive studies, the present inventors have supplied colored polymer particles to a container capable of reducing pressure and heating,
Volatilization in a short time by heating under reduced pressure while introducing an injection medium that is any one of (i) saturated steam, (ii) superheated steam, and (iii) high-humidity air having an enthalpy of 2500 kJ / kg (dry air) or more It has been found that it is possible to reduce the total amount of ingredients.

When the container is equipped with a stirring member, the peripheral speed at the maximum diameter of the stirring member is A (m / s), and the mass of the toner particles in the container is B (kg). ^{(m / (s · 3 √kg} )) ≦ A / 3 √B ≦ 0.6 (m
/ By performing the processing in (s · ³ √kg)) conditions satisfying the relationship, compaction,
It has been found that it is possible to provide toner particles having excellent fluidity without aggregation.

Furthermore, it has been found that the heat treatment system of the present invention can be used to reduce power during treatment, that is, energy and cost.

In the present invention, water vapor has a relatively small resistance due to diffusion, which hinders evaporation of volatile components existing inside the toner particles, and has a large amount of heat that can be held in comparison with a dry gas and is thermally efficient. It is possible to reduce the volatile content from the toner particles in a very short time by paying attention to the two points that are also advantageous to the above and using them.

Condensable gas such as water vapor (or high-humidity air in which water vapor occupies most of the water) can recover the vapor as a liquid in the condenser, so that a decompressed state is formed. The amount exhausted by the exhaust device needs to be exhausted entirely when dry gas is used as the carrier gas, whereas when steam is used, only the amount that cannot be recovered by the condenser may be exhausted. .

Therefore, the capacity of the exhaust device can be small, and the merit is large compared with the case of using a dry gas in terms of energy and cost. In particular, the larger the scale of the heat treatment apparatus, the greater the merit.

Further, according to the present invention, by operating the ratio of the peripheral speed of the stirring member to the mass of the toner under a predetermined condition, the compaction / aggregation of the toner particles due to the vacuum is prevented, and the toner is stirred by excessive stirring. The particles can be dried in a highly fluid state without deterioration.

In the drying using the vacuum drying used in the conventional method for producing a polymerized toner, as described above, the gas phase stays and the force for diffusing the volatile component is remarkably reduced, so that the water content is reduced. After removal by evaporation, further removal of the unreacted polymerizable monomer requires a very long drying time.

Further, in the method of vacuum drying while injecting a gas (Japanese Patent Laid-Open No. 10-207122), as described above, a gas having a small heat quantity such as an inert gas itself is heated. Drying efficiency will be reduced by taking heat from the toner particles, and if the temperature of the above-mentioned gas is not controlled by heating, etc., the airflow whose temperature has been lowered due to adiabatic expansion will enter as it is in the path for feeding the gas. As described in the examples of the publication, as shown in the fact that a large difference occurs between the heating temperature and the product temperature of the toner particles, heat is taken from the toner particles further significantly, and the drying efficiency further decreases. Resulting in. Therefore, since the drying time is extended and the heat history applied to the toner is lengthened, deformation of particles and fusion of particles occur,
As a result, there is a problem that lumps occur and the image characteristics are deteriorated.

Further, since the above-mentioned gas is a non-condensable gas, it is necessary to exhaust the charged amount as it is, and the exhaust facility (mainly a decompression pump) for maintaining decompression has a very large capacity. Therefore, there has been a problem that a great cost is required.

The present invention will be described in more detail below.

Since the injection medium in the present invention is in a depressurized state in the course of being introduced into the container in which the reduced pressure heat treatment is carried out, strictly speaking, at the time of being introduced into the reduced pressure heat treatment apparatus, the operating reduced pressure degree ( Saturated steam, superheated steam or high-humidity air that has been decompressed to the degree of decompression in the heat treatment container),
The injection medium temperature described in the specification is also in this state.

The decompression degree used in the present invention is preferably 40 kPa from the viewpoint of taking a large temperature difference ΔT between the temperature of the injection medium to be charged and the boiling point (= saturation temperature) in order to prevent dew condensation. However, since the drying efficiency is improved as the degree of vacuum is increased, it is more preferably 20.
kPa or less, further 15 kPa or less, especially 10 kPa
The following is preferable.

"Saturated steam" used in the present invention
And "superheated steam" exists only in the steam content, "saturated steam" is steam kept at the saturation temperature corresponding to the degree of pressure reduction during operation, and "superheated steam" is superheated above the saturation temperature. It is steam. Most of "high humidity air" is occupied by water vapor, but some air (which may be an inert gas such as nitrogen) is also included.

Compared with a dry gas containing almost no water vapor, which is generally used as a carrier gas, most or all of them contain water vapor, so that they retain a large amount of heat, that is, have a high enthalpy and a property. Is very different.

The enthalpy used in the present invention is the total amount of heat of 1 kg of dry air per 1 kg of dry air and water vapor [kg] contained therein, and the unit is
It is expressed in "kJ / kg (dry air)".

Further, the high-humidity air used in the present invention has a very large enthalpy because most of the high-humidity air is occupied by water vapor, unlike a gas containing almost no water vapor.

In the present invention, there are various methods for introducing the enthalpy of high-humidity air, and there is no particular limitation.

The "heat supply amount" of the injection medium used in the present invention is the flow rate fed into the apparatus per unit time and per 1 kg of toner particles, and the unit is "m".
³ / (hr · kg (toner particles)) ”.

In the present invention, in order to reduce the deterioration of the image quality due to the organic volatile components, the above-mentioned copying machine,
In order to meet the restrictions on the equipment due to downsizing and personalization of printers, etc., in the organic volatile component analysis at the heating temperature of the toner particles of 150 ° C by the headspace method, the organic volatile components of toluene conversion based on the toner particle mass are used. The total amount is preferably 500 ppm or less,
Further, it is preferably 400 ppm or less, and particularly preferably 300 ppm or less.

Next, the "water content" used in the present invention means the water content by mass, that is, the ratio of the water mass to the total mass (the sum of the dry toner mass and the water mass), and the heating loss at 105 ° C. Determined by law.

The temperature of the injection medium in the present invention is preferably lower than the glass transition temperature Tg of the toner particles.

Water vapor having a glass transition temperature Tg or higher of the toner particles causes thermal deterioration of the toner particles, resulting in problems such as fusion of particles and damaging.

Further, the introduced steam causes a temperature drop when it comes into contact with an unheated portion of the apparatus, and when it drops to a boiling point (= saturation temperature) corresponding to the degree of pressure reduction during operation, dew condensation occurs. As a result, the drying efficiency may be reduced. In order to prevent this, it is preferable to set a large temperature difference ΔT between the temperature of the injection medium to be charged and the boiling point (= saturation temperature) (however, the temperature of the device / toner particles may be sufficiently heated, and the temperature may drop). If the steam temperature is low, saturated steam corresponding to the degree of pressure reduction may be used.) If the steam temperature is low, a fairly high vacuum is required to obtain ΔT, and the exhaust equipment will be overloaded. It is preferably 30 ° C. or higher. Further, with water vapor having a glass transition temperature Tg or higher of the toner particles, the toner particles are thermally deteriorated, and problems such as fusion of particles and lumps occur.

The enthalpy of the high-humidity air used in the present invention is preferably water vapor of 2500 kJ / kg (dry air) or more, preferably 6500 kJ / kg (dry air) or more, and the enthalpy is 2500 kJ / kg (dry air). If the water vapor is less than 5), the amount of heat that can be held is small, so that heat is taken from the heated toner particles, and the drying efficiency decreases. As the high-humidity air having such a high enthalpy, it is preferable to use air having a water content of 50% or more, since it becomes easy to obtain high-humidity air having a high enthalpy. % Or more, and particularly preferably 80% or more.

The flow rate of the injection medium in the present invention is
0.01 to 0.5 m ³ / (hr · kg (toner particles)), preferably 0.03 to 0.27 m ³ / (hr
-Kg (toner particles) is preferable. Within this range, basically, if the injection medium supply flow rate is increased, the drying efficiency is improved. The injection medium supply flow rate is 0.01 m ³ / (h
If the injection medium is smaller than r · kg (toner particles), the total amount of heat supplied will be small even if the injection medium has a large amount of heat and the drying efficiency will be reduced. On the other hand, when the injection medium supply flow rate is higher than 0.5 m ³ / (hr · kg (toner particles)), a large amount of water vapor flow rate is required, which often causes a decrease in vacuum degree. The ΔT between the saturation temperature and the steam temperature corresponding to the degree of pressure reduction becomes small, and dew condensation is likely to occur.

In the present invention, when the stirring member is provided in the container, the peripheral speed at the maximum diameter of the stirring member is A
(M / s), where B (kg) is the mass of toner particles in the container, 0.01 (m / (s · ³ √kg)) ≦ A / ³ √B ≦ 0.6 (m
/ (S · ³ √kg)) Preferably, 0.04 (m / (s · ³ √kg)) ≦ A / ³ √B ≦ 0.5 (m
/ (S · ³ √kg)) it is better to carry out the process under conditions that satisfy the relationship. This represents the ratio of the peripheral speed of the stirring member to the cube root mass. The fact that the mass has a cube root means that the mass increases in proportion to the scale, but the peripheral speed follows that. Since it does not exist, it includes the meaning of correction to eliminate the difference due to scale as much as possible.

When stirring is carried out within this range, the toner particle layer can be made to flow uniformly without causing toner deterioration and compaction / aggregation due to vacuum.

Under the condition that A / ³ √B is larger than 0.6 m / (s · ³ √kg), the toner particles are rapidly heated with time because of excessive sharing due to agitation, and thermal Damages. Further, since the toner particles are mechanically loaded, the toner particles are likely to be deformed.

On the other hand, A / ³ √B is 0.01 m / (s · ³ √
Under conditions of less than (kg), it becomes insufficient to prevent the above-mentioned compaction and aggregation due to vacuum. Further, it becomes difficult to uniformly agitate the entire toner particle layer, and a portion where the toner layer stays occurs, resulting in aggregation and drying unevenness only in that portion.

The mixed state of the toner particle layer is determined by the stirring section.
Although depending on the shape of the material, the cube root toner of the present invention
ー Percentage of peripheral speed at maximum diameter of stirring member to particle mass
A / ³By setting √B within the above range, excellent fluidity can be obtained.
It is possible to dry under vacuum in various stirring parts.
It can be applied to the shape of the material.

The shape of the stirring member applicable to the present invention is not particularly limited, but it is preferable to use the ribbon-shaped stirring member shown in FIG.

Further, although the present invention finally reduces the total amount of volatile components including the polymerizable monomer composition and volatile by-products, when the toner particles contain a large amount of water, Since it exists on the surface, the volatile components cannot be reduced until the water content is removed. Therefore, in order to further improve the efficiency of removing volatile components, it is preferable to remove water in advance.

Specifically, the water content of the toner particles is preferably 3.0% or less, more preferably 1.0% or less. As a preliminary heat treatment, for example, in a high-speed hot air stream. A method of preliminarily performing a heat treatment while dispersing the powder in a parallel manner and sending it in a cocurrent flow can be mentioned. It is preferable to preliminarily make toner particles having the above-mentioned water content by using this heat treatment device capable of continuously supplying the toner particles into a high-speed hot air flow, and the toner heated by the preliminary heat treatment. It is more preferable to perform the heat treatment under reduced pressure while maintaining the temperature of the particles.

As a result, the process governed by the amount of heat given from the heat transfer surface in the depressurization heat treatment is preliminarily completed both when removing water which requires a large amount of latent heat of vaporization and when raising the temperature of a material which requires a large amount of sensible heat. In addition to reducing the processing time by bringing the difference between the heating temperature and the product temperature to a smaller value (the state where the heat transfer is less), the equipment represented by the reduced pressure heat processing equipment with the heat transfer surface can be used. The disadvantage is that the ratio of the heat transfer area to the sample charged in the sample becomes smaller as the scale increases, that is, the drying time required for the small scale takes a longer time for the large scale. The toner particles can be eliminated, and toner particles with less deterioration can be provided.

An example of an apparatus used as a preliminary heat treatment apparatus of the present invention for instantaneously performing heat treatment while sending in parallel flow in a high-speed heat air stream is, for example, a loop type air current heating tube as shown in FIG. Examples of the heat treatment apparatus having No. 5 are not particularly limited.

The preliminary heat treatment apparatus shown in FIG.
The air supplied from the discharge blower 1 is the hot air generator 2
The compressed air heated to a predetermined temperature in the
At a supersonic speed, and the processed material supplied from the raw material supply device 6 is dispersed and instantaneously (0.5
~ Tens of seconds) is processed. 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 discharged from the outlet 8. The air flow passes through the bag filter 9 and the exhaust blower 10
More out of the system.

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.

The type of piping of the air flow heat treatment apparatus is
In addition to the above loop type, various types of heat treatment pipes such as straight pipe type, expanded middle barrel to increase residence time, type that gives vortex motion to particles and prevents them from accumulating at the bottom of the horizontal pipe Although it can be used, an airflow heat treatment apparatus having a loop type airflow heating tube 5 as shown 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 include a flash jet dryer (manufactured by Seishin Enterprise Co., Ltd.) and a flash dryer (manufactured by Hosokawa Micron Corp.).

In the present invention, the toner particles are not deteriorated,
Maintaining high fluidity, the total amount of volatile components is 500pp
As a device capable of reducing pressure and heating and capable of reducing pressure to m or less and requiring a stirring member, a reduced-pressure heat treatment device having an embodiment as shown in the schematic side view of FIG. 2 is preferably used.

The reduced pressure heat treatment apparatus of the embodiment shown in FIG. 2 will be described in detail below.

In the reduced pressure heat treatment system shown in FIG. 2, toner particles are supplied into the inverse cone shaped reduced pressure heat treatment container 11 to perform the reduced pressure heat treatment. Inside the container, a stirring central shaft 13 that can be driven by a drive motor 12 extends in the longitudinal direction of the container center, and a ribbon blade 1 having a single spiral structure is formed around the stirring central shaft 13.
4 is attached to the structure.

By rotating the ribbon blades 14, 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.

Further, as shown in FIG. 2, a raw material supply port 17 for supplying toner particles is provided at the upper part of the container, and a bag filter 18 is provided at an exhaust path for reducing the pressure inside the container.
Next, the condenser 19 is connected.

Further, as shown in FIG. 2, a jacket is provided around the above-mentioned reduced pressure heat treatment container 11 for appropriately controlling the temperature inside the container and performing heat treatment at a desired temperature. Twenty is attached. Therefore, a gap is formed between the outer wall of the container and the inner wall of the jacket 20, and hot water produced in the hot water tank 21 or steam / cooling water can be passed through this gap. At the same time, hot water, steam, and cooling water discharge paths are also provided.

The pressure inside the container is reduced by the pressure reducing pump 22 from the exhaust port to the bag filter 18 and the condenser 1.
It is carried out by exhausting the water vapor in the container through 9. As shown in FIG. 2, the inside of the bag filter 18 is divided into two chambers, an upper chamber and a lower chamber, by a partition plate 23. A cylindrical filter cloth 24 is hung on the lower side of the partition plate, and the condenser 19 is hung on the upper side of the partition plate.
A backwash nozzle 25 is disposed above the center of the filter cloth 24 and the exhaust path connected to the backwash nozzle. Backwash nozzle 2
Reference numeral 5 is for intermittently injecting nitrogen or air or the above-mentioned injection medium (preferably heated nitrogen and air and the above-mentioned injection medium) to wash the filter cloth 24 under pressure.

The supply source of water vapor into the container is not particularly limited, but in general, it is generally supplied from the boiler generator, passes through the injection medium flow meter 36, and the injection medium heater. Expansion tank 2 after being heated at 26 (saturated water can be removed by separator 27 if necessary)
The pressure is reduced to near the operation decompression degree at 8, and one is uniformly supplied from the lower part of the device into the device through a dispersion plate 29 that uniformly disperses the injection medium. It is possible to prevent the toner particles from blocking at the bottom of the device.

The injection medium supplied into the reduced pressure heat treatment container became vapor mixed with the volatile components from the toner particles, passed through the bag filter 18, and was condensed and recovered by the next condenser 19 and could not be condensed. Decompression pump 2 for steam
It passes through 2 and is discharged out of the system.

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 injection medium. As a result, most of the above-mentioned condensable injection medium is recovered as water by the condenser 19, so that the decompression pump 22 as described above.
The capacity of is small.

As the reduced pressure heat treatment apparatus preferably used in the present invention, in addition to the apparatus of the embodiment used in FIG. 2, specifically, a double cone mixer (manufactured by Tokuju Seisakusho) and a Nauta mixer (manufactured by Hosokawa Micron) , Ribo Cone Mixer (Okawara Seisakusho), PV Mixer (Shinko Pantech Co., Ltd.), Vacuum Stirring Dryer Inox System (Pawrec Co.), SV Mixer (Shinko Pantech Co., Ltd.)
And so on.

The toner according to the present invention has a high image quality.
In order to faithfully reproduce smaller latent image dots, the toner also has a smaller particle diameter, specifically, a mass average diameter measured by a Coulter counter of 4 to 10 μm, and a number variation coefficient represented by the following formula. A toner having a number variation coefficient = Sn / D1 × 100 (where Sn is the standard deviation of the number distribution and D1 is the number average particle diameter) of less than 35% is most preferable.

A toner having a particle size of less than 4 μm is not preferable because it causes a large amount of transfer residual toner on the photosensitive member or the intermediate transfer member due to poor transfer efficiency, causing fog and uneven unevenness of the image due to transfer failure.

When the mass average diameter of the toner exceeds 10 μm, fusion to the member is likely to occur. Also,
If the number variation coefficient of toner exceeds 35, this tendency becomes more serious and becomes a problem.

The amount of organic volatile components in the toner of the present invention is quantified by using the headspace method. The headspace method is to seal the toner in a closed container at a constant temperature,
After heating for a certain period of time to equilibrate between the sample and the gas phase, the gas in the gas phase in the closed container is injected into the gas chromatograph to quantify the volatile components. At this time, an organic volatile component is detected using FID as a detector of the gas chromatograph. Conventionally, as a method of analyzing volatile components in a toner, a method of dissolving the toner in a solvent and injecting it into a gas chromatograph for quantification is known, but in this method, the peak of the volatile component is buried in the solvent peak. However, it is not suitable as a method for quantifying organic volatile components of toner.

The toner of the present invention contains at least a resin and a colorant, but may 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 produced by suspension polymerization or emulsion polymerization of a monomer in an emulsion containing 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 referred to in the present invention means one containing at least 50% by mass of water.

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

That is, various constituent materials such as a coloring agent 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 preparing resin particles by fusing them in an aqueous medium 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 obtained polymer particles and then the polymerization is performed using a polymerization initiator can be suitably used in the present invention.

Examples of the polymerizable monomer that can be used in the 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. .

The low softening point substance used in the present invention is preferably a compound having a main component maximum peak value measured according to ASTM D3418-8 of 40 to 90 ° C. 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 substance, or a yellow / magenta / cyan colorant shown below, which is toned black, is used.

Examples of yellow colorants include 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 state of 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 weight of the resin.
It is used by adding ~ 150 parts by mass.

The magnetic substance used in the toner of the present invention may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum and silicon. Further, the magnetic substance is mainly composed of iron oxide such as triiron tetraoxide and γ-iron oxide, and these may be used alone or in combination of two or more. These magnetic materials preferably have a BET specific surface area by the nitrogen adsorption method of ² to 30 m ² / g, particularly 3 to 28 m ² / g, and a Mohs hardness of 5 to 7.

The shape of the magnetic material is polyhedron, octahedron,
There are hexahedrons, spheres, needles, scales, etc., but polyhedrons, 8
Those having less anisotropy such as a tetrahedron, a hexahedron, and a sphere are preferable for increasing the image density. The shape of these magnetic materials is SE
It can be confirmed by M or the like. The volume average particle diameter of the magnetic material is preferably 0.05 to 0.4 μm, more preferably 0.1 to 0.3 μm. When the volume average diameter is less than 0.05 μm, the decrease in blackness becomes remarkable,
As a coloring agent for black-and-white toners, the coloring power is insufficient, and in addition, aggregation of magnetic materials becomes strong, resulting in deterioration of dispersibility. Further, it becomes very difficult to perform the uniformity treatment on the surface of the magnetic body. On the other hand, if the volume average diameter exceeds 0.4 μm, the coloring power becomes insufficient as in the case of general colorants. In addition, particularly when used as a colorant for a toner having a small particle diameter, it becomes stochastically difficult to uniformly disperse the magnetic particles in each toner particle, and the dispersibility is apt to deteriorate.

In the magnetic material used in the magnetic toner of the present invention, when the surface of the particle is made hydrophobic, the magnetic material particles are dispersed in an aqueous medium so as to have a primary particle diameter, and the coupling agent is hydrolyzed. However, it is highly preferred to use the method of surface treatment. In this hydrophobic treatment method, coalescence between magnetic particles is less likely to occur than in the gas phase, and the electrostatic repulsion action between the magnetic particles due to the hydrophobic treatment works so that the magnetic particles are almost in the state of primary particles. The surface is treated.

The method of treating the surface of the magnetic material while hydrolyzing the coupling agent in an aqueous medium does not require the use of a coupling agent such as chlorosilanes or silazanes which generates gas, and further, Up to now, magnetic particles can be easily coalesced with each other in the gas phase, and a highly viscous coupling agent, which has been difficult to treat well, can be used, and the effect of hydrophobization is great.

Examples of the coupling agent that can be used in the surface treatment of the magnetic material according to the present invention include silane coupling agents and titanium coupling agents.
A silane coupling agent is more preferably used, and R m SiYn [wherein R represents an alkoxy group, m represents an integer of 1 to 3, Y represents an alkyl group, a vinyl group, a glycidoxy group, or methacryl group. A hydrocarbon group such as a group is shown, and n is an integer of 1 to 3. ] Is shown. For example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy)
Silane, β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane,
N-phenyl-γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane,
Vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, n-butyltrimethoxysilane, Examples thereof include isobutyltrimethoxysilane, trimethylmethoxysilane, hydroxypropyritrimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane.

Among these, to improve the dispersibility of the magnetic material, 2
It is preferable to use a silane coupling agent having a heavy bond, and phenyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-glycidoxypropyltrimethoxysilane are more preferable. It is considered that this is because, particularly in the case of performing suspension polymerization, treatment with a coupling agent having a double bond improves compatibility between the magnetic substance and the polymerizable monomer. The dispersibility of the magnetic material becomes good.

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 may be further added and used.

In the polymerized toner according to the present invention, as the dispersant to be used particularly when the suspension polymerization using a dispersant is used, an inorganic compound such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate is used. , 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 product may be used as it is, but the inorganic compound may be produced 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, 0.001 to 0.1 part by mass of a surfactant may be used for finely dispersing these stabilizers. 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 substance having a low softening point are added to a 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 toner used in the present invention include vinyl resins, polyester resins, and copolymers of vinyl monomers and polyester monomers, but are not particularly limited.

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

1. Toner particle Tg measuring method: In the present invention, a differential thermal analysis measuring device (DSC measuring device), D
SC-7 (manufactured by Perkin Elmer Co., Ltd.) was used for measurement by the following method. First, the measurement sample is precisely weighed in an amount of 5 to 20 mg, preferably 10 mg. Then, this is placed in an aluminum pan, and an empty aluminum pan is used as a reference, and a temperature rising rate of 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 for measuring water content: The water content of the toner of the present invention was measured by a MA40 electronic moisture meter (manufactured by Sartorius Co., Ltd.) by a heating weight loss method at 105 ° C.

3. Method for measuring the total amount of volatile components: The amount of organic volatile components in the toner may be quantitatively determined by the headspace method as follows.

Headspace vial (volume: 22 m
To l), 300 mg of toner is precisely weighed and sealed with a crimp cap and a dedicated septum coated with a fluororesin using a crimper. Set this vial in the headspace sampler and perform the analysis under the following conditions. Then, the total area value of the peaks of the obtained GC chart is calculated by data processing. At this time, an empty vial not filled with toner is also measured as a blank at the same time, and a blank value such as an organic volatile component volatilized from the septum is subtracted from the toner measurement data. As for the amount of organic volatile components in terms of toluene based on the toner mass, several points (for example, 0.1 μl, 0.5 μl, 1.0 μl) prepared by precisely weighing only toluene in a vial were prepared. Before performing the measurement, perform a measurement under the following analysis conditions respectively, then create a calibration curve from the charged amount of toluene and the area value of toluene, and based on this calibration curve, determine the area value of the organic volatile components of the toner as the toner mass. It may be converted into the mass of toluene based on.

<Measuring device> Headspace sampler: HEWLETT PACK
ARD 7694 Oven temperature: 150 ° C Sample heating time: 60 minutes Sample loop (Ni): 1 ml Loop temperature: 170 ° C Transfer line temperature: 190 ° C Pressurization time: 0.50 minutes LOOP FILL TIME: 0.01 minutes LOOP EQ TIME : 0.06 minutes INJECT TIME: 1.00 minutes GC cycle time: 80 minutes Carrier gas: He GC: HEWLETT PACKARD 6890GC
(Detector: FID) Column: HP-1 (inner diameter 0.25 μm × 30 m), carrier gas: He Oven: 35 ° C .: hold for 20 minutes, 30 at 20 ° C./minute
Temperature rise to 0 ° C Hold for 20 minutes INJ: 300 ° C DET: 320 ° C Splitless, constant pressure (20ps
i) mode

[0124]

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

[Example 1] A surface-treated magnetic material was manufactured by the following method.

In an aqueous solution of ferrous sulfate, 1% of iron was added to the iron element. 0 to 1.1 equivalents of caustic soda solution, 0.95 mass% sodium hexametaphosphate in terms of phosphorus element with respect to iron element,
0.95 mass% sodium silicate in terms of silicon element was mixed with iron element to prepare an aqueous solution containing ferrous hydroxide.

While maintaining the pH of the aqueous solution at around 13,
Air was blown in and an oxidation reaction was carried out at 80 to 90 ° C. to obtain a slurry liquid of magnetic particles. After washing and filtering, the water-containing slurry liquid was once taken out. At this time, a small amount of water sample was taken and the water content was measured. Next, the water-containing sample was re-dispersed in another aqueous medium without being dried, the pH of the re-dispersion liquid was adjusted to about 6, and the n-hexyltrimethoxysilane coupling agent was magnetically mixed with sufficient stirring. Add 1.9 parts by mass and 1.1 parts by mass of γ-methacryloxypropyltrimethoxysilane coupling agent to 100 parts by mass of iron oxide (the amount of magnetic particles was calculated as the value obtained by subtracting the water content from the water-containing sample). Then, a coupling treatment was performed. The generated hydrophobic magnetic particles are washed, filtered, and
After drying, the obtained particles were sufficiently crushed to obtain a surface-treated magnetic substance having a number average particle diameter of 0.13 μm and a number average variation coefficient of 8.

To 720 parts by mass of ion-exchanged water, 0.1M-N
a ₃ PO ₄ aqueous solution (450 parts by mass), 1N hydrochloric acid (16 parts by mass) was added, and the mixture was heated to 60 ° C., and then 1.0M-CaCl ₂ aqueous solution (67.7 parts by mass) was added to add Ca ₃ (PO ₄ ) ₂ . An aqueous medium containing was obtained.

On the other hand, 78 parts by mass of styrene, 22 parts by mass of n-butyl acrylate, 1 part by mass of saturated polyester resin, 0.20 parts by mass of divinylbenzene, and 1 part by mass of negative charge control agent (monoazo dye-based Fe compound). 85 parts by mass of the surface-treated magnetic material The above formulation was uniformly dispersed and mixed using a homogenizer.

This monomer composition was heated to 60 ° C., and 7 parts by mass of an ester wax (maximum value of endothermic peak in DSC: 72 ° C.) of 7 parts was added thereto and dissolved therein. 4 parts by mass of oxy-2-ethylhexanoate was dissolved.

The above polymerizable monomer system was added to the aqueous medium, and the mixture was mixed at 60 ° C. under N ₂ atmosphere with a TK homomixer (Tokushu Kika Kogyo Co., Ltd.) at 10,000 rpm at 1 rpm.
The mixture was stirred for 5 minutes and granulated. Then, the mixture was stirred at 80 ° C. for 8 hours while stirring with a paddle stirring blade. After completion of the reaction, the suspension is cooled, hydrochloric acid is added to dissolve the dispersant at pH 2 or less,
Filtered and washed with water, moisture content 22%, mass average particle size 7.2μm
Wet toner particles were obtained.

The toner particles thus obtained were preliminarily heat-treated under the following conditions using an apparatus having a pipe diameter of 0.1016 m in an air-flow heat-treatment section and having the same configuration as that shown in FIG.

Blowing temperature: 90 ° C. Blowing air volume: 10 m ³ / min Raw material supply rate: 50 kg / hr

The water content after the treatment was 0.20%, and the glass transition temperature of the toner particles was measured at this point.
It was 58 ° C.

Volatile components were removed from the toner particles by using a reduced pressure heat treatment apparatus having a capacity of 100 L as shown in FIG. Heating temperature: 50 ° C. Decompression degree during processing: 3 kPa Toner mass B: 45 kg Maximum diameter of stirring member: 0.6 m Peripheral speed at maximum diameter of stirring member A: 0.785 m / s A / ³ √B: 0.22 m / (s・³ √kg), temperature is 50 ℃, enthalpy is about 14000kJ
/ Kg (dry air) and high-humidity air having a water content of about 90% were introduced so that the supply amount was 0.13 m ³ / (hr · kg (toner particles)).

Under the above conditions, heat treatment under reduced pressure was performed for 3 hours.

At the end of the treatment, the water content was 0.17%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 200 ppm.

Further, the obtained toner particles had no aggregated particles and were very excellent in fluidity.

100 parts by mass of the toner particles thus obtained and silica having a primary particle diameter of 12 nm were treated with hexamethyldisilazane and then treated with silicone oil.
1.0 part by mass of hydrophobic silica fine powder having a value of 120 m ² / g was mixed with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a toner.

Using this toner, evaluation was performed using a modified LBP-1760 manufactured by Canon Inc. as an image forming apparatus.

First, 100 g of the obtained toner was filled in a cartridge, and the amount of toner on paper was adjusted to 0.8 mg / cm ² under high temperature and high humidity (30 ° C., 80% RH), and an image was obtained. A solid black image having a density of 1.42 was obtained.
Thereafter, as a toner deterioration acceleration test, idle rotation was performed for 2 hours, and then an image output test was performed on 1000 sheets with an image pattern consisting of only horizontal lines having a printing rate of 2%. As a result, with the obtained toner, a very good image having no fog on the non-image area was obtained after printing 1000 sheets. The evaluation results are shown in Table 1.

The evaluation items described in the examples of the present invention and the comparative examples and their criteria will be described.

<Image Density> Regarding the image density, a solid image portion was formed, and this solid image was measured by a Macbeth reflection densitometer (manufactured by Macbeth Co.).

<Fog> Fog is measured by REFLECTMETER MODELTC-6D manufactured by Tokyo Denshoku Co., Ltd.
It was measured using S. A green filter was used as a filter, and fog was calculated from the following formula.

[0145]

[Equation 1]

The criteria for determining fog are as follows. A: Very good (less than 1.5%) B: Good (1.5% or more and less than 2.5%) C: Normal (2.5% to less than 4.0%) D: Bad (4% or more)

[Example 2] Up to the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using the reduced pressure heat treatment apparatus having the same mode as in Fig. 2.

The conditions of the reduced pressure heat treatment were the same as those in Example 1 except that the temperature was 50 ° C., the enthalpy was about 2500 kJ / kg (dry air), and high-humidity air having a moisture content of 60% was introduced.
A heat treatment under reduced pressure was performed under the same conditions as in.

At the end of the treatment, the water content was 0.19%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 305 ppm.

Further, the obtained toner particles had no agglomerated particles and were very excellent in fluidity.

The toner particles thus obtained were subjected to the same operation as in Example 1 to prepare a toner, and the same evaluation was carried out. As a result, very good results were obtained. The evaluation results are shown in Table 1.

Example 3 Up to the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using the reduced pressure heat treatment apparatus having the same mode as that shown in FIG.

The reduced pressure heat treatment was carried out under the same conditions as in Example 1 except that superheated steam having a temperature of 50 ° C. was added.

At the end of the treatment, the water content was 0.17% and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 170 ppm.

Further, the obtained toner particles had no agglomerated particles and were very excellent in fluidity.

The toner particles thus obtained were subjected to the same operation as in Example 1 to prepare a toner, and the same evaluation was carried out. As a result, very good results were obtained. The evaluation results are shown in Table 1.

Example 4 The reduced pressure heat treatment was performed under the same conditions as in Example 3 except that the toner particles having a water content of 2.9% after the preliminary heat treatment were used for the reduced pressure heat treatment.

At the end of the treatment, the water content was 0.18%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 250 ppm.

Further, the obtained toner particles had no agglomerated particles and were very excellent in fluidity. The toner particles thus obtained were processed in the same manner as in Example 1 to prepare a toner, and the same evaluation was carried out, and very good results were obtained. The evaluation results are shown in Table 1.

[Example 5] Up to the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using the reduced pressure heat treatment apparatus having the same mode as in Fig. 2.

The reduced pressure heat treatment conditions were the same as in Example 3 except that the supply flow rate of superheated steam was 0.5 m ³ / (hr · kg (toner particles)) and the pressure reduction degree during the treatment was 5 kPa. Was subjected to a reduced pressure heat treatment.

At the end of the treatment, the water content was 0.31% and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 300 ppm.

Further, the obtained toner particles had no agglomerated particles and were very excellent in fluidity. The toner particles thus obtained were subjected to the same operations as in Example 1 to prepare a toner, and the same evaluation was carried out, and good results were obtained. The evaluation results are shown in Table 1.

[Example 6] Up to the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using the reduced pressure heat treatment apparatus having the same mode as in Fig. 2.

The conditions of the reduced pressure heat treatment were the same as those in Example 3 except that the supply flow rate of superheated steam was 0.01 m ³ / (hr · kg (toner particles)) and the pressure reduction degree during the treatment was 2.5 kPa.
The heat treatment under reduced pressure was performed under the same conditions as in.

At the end of the treatment, the water content was 0.2% and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 400 ppm.

The obtained toner particles had no agglomerated particles and were very excellent in fluidity. The toner particles thus obtained were processed in the same manner as in Example 1 to prepare a toner, and the same evaluation was carried out. As a result, fog was slightly deteriorated, but it was at a practically acceptable level. The evaluation results are shown in Table 1.

Example 7 Toner particles obtained in the same manner as in Example 1 were treated using a reduced pressure heat treatment apparatus having the same mode as in FIG. 2 up to the preliminary heat treatment.

The reduced pressure heat treatment conditions were the same as in Example 1 except that the degree of reduced pressure during the treatment was 4.2 kPa and saturated steam at a temperature of about 30 ° C. was charged into the reduced pressure heat treatment apparatus. A reduced pressure heat treatment was performed. At the end of processing,
The water content was 0.35%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 360 ppm.

Further, the obtained toner particles had no agglomerated particles and were very excellent in fluidity. The toner particles thus obtained were subjected to the same operations as in Example 1 to prepare a toner, and the same evaluation was carried out, and good results were obtained. The evaluation results are shown in Table 1.

[Embodiment 8] Up to the preliminary heat treatment, the toner particles obtained in the same manner as in Embodiment 1 were treated using the reduced pressure heat treatment apparatus having the same mode as in FIG.

[0172] The reduced pressure heat treatment conditions are as follows: toner mass B: 45
kg, peripheral speed at maximum diameter of stirring member A: 1.884 m /
s, A / ³ √ B: 0.53 m / (s · ³ √ kg), except that the heat treatment under reduced pressure was performed under the same conditions as in Example 1. At the end of the treatment, the water content was 0.16%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 150 ppm.

In addition, the obtained toner particles were found to be expected to be thermally aggregated. The toner particles thus obtained were processed in the same manner as in Example 1 to prepare a toner, and the same evaluation was carried out. A slight deterioration in fog was observed, but it was at a practically acceptable level.

The evaluation results are shown in Table 1.

Example 9 Up to the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using the reduced pressure heat treatment apparatus having the same mode as in FIG.

The reduced pressure heat treatment conditions are: toner mass B: 45
peripheral speed A at the maximum diameter of kg and stirring member A: 0.06 m /
s, A / ³ √ B: 0.018 m / (s · ³ √ kg), except that the heat treatment under reduced pressure was performed under the same conditions as in Example 1. At the end of the treatment, the water content was 0.20%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 260 ppm.

Further, in the obtained toner particles, some toner particles which were expected to be compacted and aggregated due to the vacuum were found. The toner particles thus obtained were processed in the same manner as in Example 1 to prepare a toner, and the same evaluation was carried out. A slight deterioration in fog was observed, but it was at a practically acceptable level. The evaluation results are shown in Table 1.

Comparative Example 1 Up to the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using the reduced pressure heat treatment apparatus having the same mode as in FIG.

The reduced pressure heat treatment conditions are 30 ° C./80% RH.
Under the same conditions as in Example 3, except that low-humidity air having an enthalpy of about 100 kJ / kg (dry air) and a water content of about 5%, which was obtained by heating the above air under reduced pressure and 45 ° C., was placed in the reduced pressure heat treatment apparatus. A heat treatment under reduced pressure was performed below. At the end of the treatment, the water content was 0.19% and the total amount of organic volatile components in toluene obtained by the headspace method was 5%.
It was 15 ppm.

The obtained toner particles had no agglomerated particles and were very excellent in fluidity. Also,
In order to maintain the same degree of reduced pressure as in Example 3, a vacuum pump having a larger capacity than the vacuum pump used in Example 3 was required.
The toner particles thus obtained were processed in the same manner as in Example 1 to prepare a toner, and the same evaluation was performed. As a result, a decrease in image density and deterioration of fog were observed.

Comparative Example 2 Up to the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using the reduced pressure heat treatment apparatus having the same mode as in FIG.

The reduced pressure heat treatment was carried out under the same conditions as in Example 3 except that superheated steam having a temperature of 65 ° C. was charged into the reduced pressure heat treatment apparatus. At the end of the treatment, the water content was 0.14%, and the total amount of organic volatile components in toluene calculated by the headspace method was 150 p.
It was pm.

Further, in the obtained toner particles, many agglomerated toner particles were mixed. The toner particles thus obtained were processed in the same manner as in Example 1 to prepare a toner, and the same evaluation was performed. As a result, a decrease in image density and deterioration of fog were observed. The evaluation results are shown in Table 1.

Comparative Example 3 Up to the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using the reduced pressure heat treatment apparatus having the same mode as in FIG.

The reduced pressure heat treatment conditions are: toner mass B: 45
kg, peripheral speed at maximum diameter of stirring member A: 0.031 m /
^{s, A / 3 √B: 0.0088m} / except that (s · ³ √kg) is performed a vacuum heat treatment under the same conditions as in Example 3. At the end of the treatment, the water content was 0.2%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 200 ppm.

Further, in the obtained toner particles, a large number of toner particles, which are expected to be compacted / aggregated due to the vacuum, were mixed. Furthermore, the organic volatile component of the aggregated toner particles was measured and found to be 320 ppm.

The toner particles thus obtained were processed in the same manner as in Example 1 to prepare a toner, and the same evaluation was carried out. As a result, a decrease in image density and a decrease in fog were observed. The evaluation results are shown in Table 1.

[Comparative Example 4] Up to the preliminary heat treatment, the toner particles obtained in the same manner as in Example 1 were treated using the reduced pressure heat treatment apparatus having the same mode as in FIG.

The reduced pressure heat treatment conditions are: toner mass B: 45
peripheral speed A at kg, maximum diameter of stirring member: 2.39 m /
^{s, A / 3 √B: 0.67m} / except that (s · ³ √kg) is performed a vacuum heat treatment under the same conditions as in Example 3. At the end of the treatment, the water content was 0.15%, and the total amount of organic volatile components in terms of toluene obtained by the headspace method was 150 ppm.

Further, in the obtained toner particles, a large number of toner particles expected to be thermally aggregated were mixed.

The toner particles thus obtained were processed in the same manner as in Example 1 to prepare a toner, and the same evaluation was carried out. As a result, a decrease in image density and a decrease in fog were observed. The evaluation results are shown in Table 1.

[0192]

[Table 1]

[0193]

According to the present invention, all the volatile components present in the toner particles obtained by the polymerization method are uniformly reduced in a short time, and at the same time toner particles free from aggregation and deterioration are obtained. A method for producing particles can be realized.

Further, according to the present invention, it is possible to realize a method for producing toner particles, which is capable of obtaining a high-quality image without image defects caused by residual volatile components and agglomerated / deteriorated toner particles.

In addition, according to the present invention, it is possible to reduce the energy and cost required for removing the volatile component.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of an apparatus in which toner particles are dispersed in a powder form in a hot air stream and heated while being sent in parallel with a high-speed air stream.

FIG. 2 is a schematic view showing an example of an apparatus for performing a reduced pressure heat treatment while charging an injection medium.

[Explanation of symbols]

1. Discharge blower 2. Hot air generator 3. Airflow dispersion unit 4. Air flow outlet 5. Loop type air flow heating pipe 6. Raw material supply device 7. Cyclone 8. Outlet 9. Bag filter 10. Exhaust blower 11. Decompression heat treatment container 12. Drive motor 13. Central axis of stirring 14. Ribbon wings 17. Raw material supply port 18. Bug filter 19. condenser 20. Jacket 21. Hot water tank 22. Vacuum pump 23. Partition board 24. Filter cloth 25. Backwash nozzle 26. Injection medium heater 27. separator 28. Expansion tank 29. Disperser 36. Injection medium flow meter

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshinori Tsuji             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Akira Hashimoto             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F term (reference) 2H005 AA02 AA03 AB06 AB09 CA26                       CB20 EA03 EA07 EA10 FA06

Claims (21)

[Claims] 1. A toner particle produced in an aqueous dispersion medium is washed and dehydrated, and the obtained wet toner particle is supplied to a container and saturated at a temperature lower than the glass transition temperature Tg of the toner particle. Heating of toner particles by the headspace method by performing reduced pressure heat treatment while introducing an injection medium selected from the group consisting of steam, superheated steam, or high-humidity air having an enthalpy of 2500 kJ / kg (dry air) or more into the container. A method for producing toner particles, characterized in that, in an organic volatile component analysis at a temperature of 150 ° C., the total amount of organic volatile components in terms of toluene based on the toner particle mass is 500 ppm or less. 2. The method for producing toner particles according to claim 1, wherein the high humidity air has a water content of 50% or more. 3. The method for producing toner particles according to claim 1, wherein the high humidity air has a water content of 60% or more. 4. The enthalpy of high-humidity air is 6500 kJ.
/ Kg (dry air) or more, The method for producing toner particles according to claim 1, wherein. 5. The method for producing toner particles according to claim 1, wherein the high-humidity air has a water content of 50% or more and an enthalpy of 6500 kJ / kg (dry air) or more. 6. The method for producing toner particles according to claim 1, wherein the high-humidity air has a water content of 60% or more and the enthalpy is 6500 kJ / kg (dry air) or more. 7. The method for producing toner particles according to claim 1, wherein the high-humidity air has a water content of 80% or more and the enthalpy is 6500 kJ / kg (dry air) or more. 8. The method for producing toner particles according to claim 1, wherein the container has a stirring means. 9. The stirring means is performed using a stirring member provided in a container, the peripheral speed at the maximum diameter of the stirring member is A (m / s), and the mass of toner particles in the container is B ( kg)
If a, 0.01 (m / (s · 3 √kg)) ≦ A / 3 √B
≦ 0.6 (m / (s · 3 √kg)) method for producing toner particles according to any one of claims 1 to 8, characterized in that the process under the conditions satisfying the relationship. 10. The stirring means is performed using a stirring member provided in a container, the peripheral speed at the maximum diameter of the stirring member is A (m / s), and the mass of toner particles in the container is B ( k
If the g), 0.04 (m / ( s · 3 √kg)) ≦ A / 3 √B ≦ 0.5 (m
/ (S · ³ √kg)) method for producing toner particles according to any one of claims 1 to 8, characterized in that the process under the conditions satisfying the relationship. 11. The supply flow rate of the injection medium is 0.01 to.
The method for producing toner particles according to any one of claims 1 to 10, wherein the amount is 0.5 m ³ / (hr · kg (toner particles)). 12. The supply flow rate of the injection medium is 0.03 to
The method for producing toner particles according to any one of claims 1 to 10, wherein 0.27 m ³ / (hr · kg (toner particles)). 13. The method for producing toner particles according to claim 1, wherein the total amount of organic volatile components in terms of toluene is 400 ppm or less. 14. The method for producing toner particles according to claim 1, wherein the total amount of organic volatile components in terms of toluene is 300 ppm or less. 15. The water content of the toner particles supplied to the reduced pressure heat treatment is 3.0% or less by performing a preliminary heat treatment before the reduced pressure heat treatment. 15. The method for producing toner particles according to any one of 1 to 14. 16. The method for producing toner particles according to claim 1, wherein the toner particles supplied to the reduced pressure heat treatment have a water content of 1.0% or less. 17. The preliminary heat treatment is a method of performing the heat treatment while dispersing the wet toner particles in a high-speed hot air stream and simultaneously sending the wet toner particles in a parallel flow. The method for producing toner particles according to any one of claims 1 to 16, wherein the toner particles can be continuously supplied and treated. 18. The production of toner particles according to claim 1, wherein the polymerization initiator used for the polymerization in the aqueous medium is a peroxide type polymerization initiator. Method. 19. The production of toner particles according to claim 1, wherein the polymerizable monomer composition contains at least a polymerizable monomer, a colorant and a magnetic material. Method. 20. The method for producing toner particles according to claim 19, wherein the magnetic material is subjected to a hydrophobic treatment with a coupling agent. 21. The method for producing toner particles according to claim 19, wherein the magnetic substance in the magnetic toner is treated with a silane coupling agent having a double bond.