JP4521953B2 - Toner production method - Google Patents

Description

【０２０８】
【発明の効果】
以上説明した様に、本発明の製造方法によれば、重合性単量体組成物の造粒時の粒度分布をシャープにすることができ、最終的に分級工程を必要とせず、また、分級したとしても、高収率で粒度分布のシャープなトナーが得られる。
【図面の簡単な説明】
【図１】本発明の製造方法に用いられる造粒装置の一例を示す概略断面図である。
【図２】図１における撹拌装置の断面図である。
【符号の説明】
１ 造粒容器
２ 撹拌装置
３ 撹拌シャフト
４ 撹拌羽根
５ スクリーン
６ 撹拌室
７ ジャケット
８ 液面
９ モータ
１０ インバータ
１１ 電流計[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing toner used in recording methods such as electrophotography, electrostatic recording, and toner jet recording.
[0002]
[Prior art]
There are many known electrophotographic methods as described in U.S. Pat. No. 2,297,691, and various methods are generally used using a photoconductor made of a photoconductive material. Then, an electric latent image is formed on the photoconductor, and the latent image is developed with toner to form a visible image. If necessary, the toner image is transferred to a transfer material such as paper, and then heated. Alternatively, the toner image is fixed on the transfer material by pressure or the like to obtain a copy or printed matter. Various methods have been proposed in the past for developing using toner or fixing a toner image.
[0003]
Conventionally, a toner used for these purposes is generally obtained by melt-kneading a colorant composed of a dye or pigment in a thermoplastic resin, uniformly dispersing it, and then finely pulverizing it with a fine pulverizer. It has been manufactured by classifying with a classifier so as to have a desired particle size.
[0004]
Although this method can produce a very good toner, it has certain limitations, i.e., limited choice of toner material. For example, the toner coarse powder must be sufficiently brittle and capable of being finely pulverized by an economically possible manufacturing apparatus. However, if the toner coarse powder is made brittle in order to satisfy these requirements, when the toner coarse powder is actually finely pulverized at a high speed, the particle size range of the formed particles tends to be widened, especially relatively large. There arises a problem that fine particles are contained in the finely pulverized product at a ratio. Further, the toner obtained from such a brittle material is easily subjected to further pulverization or powdering in a developing device such as a copying machine. Further, in this method, it is difficult to completely disperse solid fine particles such as a colorant in the resin, and depending on the degree of dispersion, fogging at the time of image formation, image density reduction, color mixing property or Sufficient attention must be paid to the dispersion of the colorant because it causes poor transparency and the like. Further, exposure of the colorant to the fracture surface of the pulverized particles may cause a change in development characteristics.
[0005]
On the other hand, in order to overcome the problems of the toner due to the pulverization method, suspension polymerization method toners such as JP-B 36-10231, JP-B 43-10799 and JP-B 51-14895 are used. Various polymerization toners and production methods thereof have been proposed. For example, in a suspension polymerization method toner, a monomer composition obtained by uniformly dissolving or dispersing a polymerizable monomer, a colorant and a polymerization initiator, and further, if necessary, a crosslinking agent, a charge control agent, and other additives. After that, the monomer composition is dispersed in a continuous phase containing a dispersion stabilizer, for example, an aqueous phase using a suitable stirrer, and at the same time, a polymerization reaction is performed, and a toner having a desired particle size. Get particles.
[0006]
In this method, since the pulverization process is not included at all, the toner does not need to be brittle, and a soft material can be used as the resin, and the colorant is not exposed to the surface of the particles. There is an advantage that a toner having frictional charging properties can be obtained. Further, since the particle size distribution of the obtained toner is relatively sharp, the classification step can be omitted, or the toner can be obtained in a high yield even if the classification is performed. Further, since a large amount of a low softening point substance can be encapsulated in the toner as a release agent, there is an advantage that the obtained toner has excellent offset resistance.
[0007]
[Problems to be solved by the invention]
However, due to the characteristics of the production method of the polymerized toner, this granulation step is very important in order to obtain toner particles having a desired particle size and a sharp particle size distribution in the granulation step. Conventionally, various agitation devices, emulsification devices, and the like are used in this granulation step, but there is a problem that it is very difficult to obtain polymer particles having a fine, uniform, and sharp particle size distribution. In this granulation step, the liquid may stay in the granulation container. In such a case, the granulated droplets are united, resulting in polymer particles having a broad particle size distribution. There is a problem that it ends up.
[0008]
In addition, if the stirring force of the stirring device is excessive, a large amount of cavitation occurs at the tip of the stirring blade, erosion occurs due to this bubble destruction, and the durability of the stirring blade is greatly reduced, such as damaging the surface of the stirring blade. . Furthermore, excessive agitation leads to excessive power consumption, leading to deterioration in toner production running costs.
[0009]
Accordingly, an object of the present invention is to provide a toner production method that efficiently produces a toner having a sharp particle size distribution and greatly improves the durability of a stirring device in the production of toner by a polymerization method. .
[0010]
[Means and Actions for Solving the Problems]
The above object is achieved by the present invention described below. That is, the present invention relates to a toner production method including at least a toner particle granulation step and a polymerization step.
The toner particle granulation step is a step of granulating by dispersing a polymerizable monomer composition containing a polymerizable monomer in an aqueous dispersion medium containing a dispersion stabilizer in a granulation vessel. Yes,
In the granulation vessel, a stirring device having a high shearing force is provided,
The stirring device includes a stirring blade and a stirring chamber that rotate at a high speed,
A liquid material containing the polymerizable monomer composition and the aqueous dispersion medium is mixed with the stirring. Room Are sucked from above and below, and stirred in the stirring chamber. Room Granulation is performed by being ejected from the side of
Volume V (m of the liquid material present in the granulation container ^Three ) And the use power P (kW) of the stirring device
20 <P / V <80
Have the relationship
The inner diameter D of the granulation container, the inner diameter D and the volume V (m ^Three Between the liquid level height L obtained from the above and the distance l of the stirring device from the bottom of the granulation vessel
0.5 <L / D <2.0, 0.04 <l / L <0.6
Have the relationship
Between the diameter d of the stirring blade and the inner diameter D,
0.1 <d / D <0.3
The toner production method is characterized by the following relationship.
[0011]
As a result of intensive studies, the present inventors granulated the polymerizable monomer composition in a granulation container to obtain droplet particles having a sharp particle size distribution.
(1) Liquid volume V (m ^Three ) And use power P (kW) of the stirring device,
(2) Relationship between the inner diameter D of the granulation vessel, the liquid level height L obtained from the liquid material present in the vessel during the granulation step, and the distance l of the stirring device from the bottom of the granulation vessel,
(3) The direction in which the liquid material existing in the container is sucked into the stirring chamber of the stirring device to be used and the direction of ejection from the stirring chamber, and the relationship between these,
That is, it has been found that the flow pattern of the liquid in the granulation vessel and the stirring strength for forming the flow are very important. The toner production method of the present invention is based on such knowledge.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described in more detail with reference to preferred embodiments.
[0013]
A schematic cross-sectional view of a preferred granulating apparatus used in the present invention is shown in FIGS. In FIG. 1, 1 is a granulation vessel, 2 is a stirring device, 3 is a stirring shaft for driving the stirring device, 7 is a jacket, 8 is a liquid level, 9 is for driving the stirring device The motor 10 is an inverter for controlling the rotation speed of the motor, and 11 is an ammeter for measuring the load current value of the motor.
[0014]
FIG. 2 is an enlarged cross-sectional view of the stirring device in FIG. 1, wherein 4 is a stirring blade, 5 is a screen, and 6 is a stirring chamber.
[0015]
The number of rotations of the motor 9 for driving the stirring device is controlled by the voltage E (V) of the inverter 11, and each has a unique number of revolutions with respect to the unique voltage E. When the stirrer is driven, the load current value I (A) of the motor is measured by the ammeter 11.
[0016]
The power P (kW) used in the present invention is represented by the following equation:
P (kW) = 1.732 × I × E / 1000
Liquid volume V (m ^Three ) And the use power P (kW) of the stirring device
15 <P / V <100
More preferably, the liquid volume V (m ^Three ) And the use power P (kW) of the stirring device
20 <P / V <80
Have the relationship.
[0017]
P / V ≦ 15
In this case, the stirring force of the stirring device is weak, and the liquid stays in the granulation vessel in the granulation step of the present invention. In such a case, the shearing force to the liquid dispersion medium containing the polymerizable monomer composition and the dispersion stabilizer is very weak, so that the dispersion of the polymerizable monomer composition to the desired liquid dispersion medium can be prevented. I can't get it. As a result, the desired toner particle diameter cannot be obtained, and the granulated droplets coalesce, resulting in a broad particle size distribution. In addition, due to the coalescence of the particles, the resulting droplets of the polymer particles become large, so the amount of heat generated by the reaction heat from the particles becomes very large, and it becomes difficult to control the temperature in the granulation vessel. When the temperature control becomes difficult, the obtained toner particles are adversely affected by thermal deterioration and the like, and adversely affect the toner quality.
[0018]
P / V ≧ 100
In this case, the stirring force of the stirring device becomes excessive. In this case, a lot of cavitation is generated at the tip of the stirring blade, erosion due to this bubble destruction occurs, and the durability of the stirring blade is greatly reduced, such as damaging the surface of the stirring blade. Furthermore, excessive stirring also requires more power than necessary, leading to worsening toner manufacturing running costs.
[0019]
In contrast, the present invention provides a liquid volume V (m ^Three ) And the use power P (kW) of the stirring device
15 <P / V <100
More preferably,
20 <P / V <80
Thus, the problem is solved by producing the polymerization toner with the following relationship.
[0020]
Also, the inner diameter D of the granulation container, the volume V (m ^Three ), The liquid level height L obtained from the liquid material, and the distance l from the bottom of the granulation vessel to the stirring device
0.5 <L / D <2.0, 0.04 <l / L <0.6
Have the relationship.
[0021]
In such a granulating stirrer, the dispersion liquid composed of the polymerizable monomer composition and the liquid dispersion medium enters the stirrer chamber 6 from the upper part of the stirrer 2 and the lower part of the stirrer 2 and rotates at high speed. After stirring by strong shearing force, impact and turbulence generated between the screen 4 and the screen 5 to form micron-order monomer composition particles, the particles are ejected from the gap between the screens into the granulation vessel. In the stirring device configured as described above, the shape of the stirring blade, the mesh diameter of the screen, and the gap between the stirring blade and the screen can be changed, and the viscosity of the monomer composition and the final desired monomer composition can be changed. Depending on the particle size and the like, a suitable form can be used.
[0022]
In the granulation process, in order to perform granulation at a certain temperature, the granulation container is usually made into a jacket structure, and warm water or steam, cold water, etc. are flowed into the jacket to control the temperature in the container. It is preferred to do so.
[0023]
In such a granulation stirrer, the flow of fluid is sucked into the stirrer from the upper and lower portions of the stirrer and ejected to the side surface. In this case, the polymerizable monomer composition is very efficiently fed into the stirring chamber, and monomer composition particles having a sharp particle size distribution are obtained.
[0024]
However, the liquid level height L obtained from the liquid material present in the container during the granulation step, and the distance l from the bottom of the granulation container to the stirring device are:
l / L ≧ 0.6
In this case, a vigorous vortex is formed on the free liquid surface formed by the liquid material existing in the container by the suction flow to the upper part of the stirring device obtained by stirring of the stirring device, and cavitation occurs in the fluid. . In general, it is well known that cavitation formed by a stirring device lowers stirring efficiency. However, in the present invention as well, strong shear force generated between the stirring blade and the screen due to the reduction in stirring efficiency caused by this cavitation. In addition, it is difficult to form an impact force, and there is a problem that the particle size distribution of the obtained particles becomes wide.
[0025]
Also,
l / L ≦ 0.04
In this case, the suction flow from the lower part of the stirring device obtained by stirring by the stirring device has a short distance from the bottom surface of the granulation vessel, so that a sufficient suction channel cannot be obtained. As a result, the suction flow is hindered by pressure loss, and sufficient liquid suction cannot be obtained, so that the ejection from the side surface is weakened, and the necessary shearing force and impact force are generated between the stirring blade 4 and the screen 5. There was a problem that the desired sharp particle size distribution could not be obtained.
[0026]
In contrast, the present invention relates to the inner diameter D of the granulation vessel, the liquid level height L obtained from the liquid material present in the vessel during the granulation step, and the distance l of the stirring device from the bottom of the granulation vessel. Between
0.5 <L / D <2.0, 0.04 <l / L <0.6
A stirrer is installed so as to have the relationship of
0.6 <L / D <1.8, 0.06 <l / L <0.3
This problem is improved because the polymerization method toner is produced by installing the stirring device so as to have the following relationship.
[0027]
Furthermore, normally, when granulating, the polymerizable monomer composition is charged into a granulation vessel charged with a liquid dispersion medium incompatible with the monomer composition, and granulated by dispersing the polymerizable monomer composition. In this case, it is important that the polymerizable monomer composition is sufficiently mixed in the dispersion medium. As in the present invention, the inner diameter D of the granulation container and the container during the granulation process are important. Between the liquid level height L obtained from the liquid substance existing in the inside and the distance l of the stirring device from the bottom of the granulation vessel
0.5 <L / D <2.0, 0.04 <l / L <0.6
The stirring device is installed so as to have the relationship of
0.6 <L / D <1.8, 0.06 <l / L <0.3
Since the stirring device is installed so as to have the relationship, it can be put in very smoothly.
[0028]
The particle diameter of the obtained particles is usually controlled by the amount of the dispersion stabilizer used and the number of rotations of the stirring blade.
[0029]
Further, the value of d / D, which is the ratio between the diameter d of the stirring blade and the inner diameter D of the granulation vessel, is a very important factor in achieving uniform stirring in the vessel. That is, if d / D is small, sufficient agitation cannot be obtained, and if d / D is too large, the collision force between the flow of fluid ejected from the side surface of the agitator and the inner wall of the container increases, and turbulence is generated. Or the ejection amount is reduced, which is not preferable. Thus, as a result of investigations by the present inventors, it was found that d / D is preferably in the range of 0.05 to 0.35, and more preferably in the range of 0.10 to 0.30.
[0030]
Furthermore, in the case of producing a toner that has both a fixing property and a blocking resistance, such as when the toner has a core / shell structure and the shell portion is formed by polymerization, the same proportion of the low softening point substance is contained in each toner particle. In this respect, it is important to control the particle size distribution during granulation. In the production method of the present invention, since the particle size distribution of the droplet particles of the polymerizable monomer composition at the time of granulation can be sharpened, such a problem can be solved.
[0031]
As the main component of the core portion, a low softening point material is preferable, and a compound having a main maximum peak value measured according to ASTM D3418-8 of 40 to 90 ° C. is preferable. If the maximum peak is less than 40 ° C., the self-aggregation force of the low softening point substance becomes weak, and as a result, the high temperature offset resistance at the time of toner image transfer becomes weak, which is not preferable. On the other hand, when the maximum peak exceeds 90 ° C., the fixing temperature of the toner becomes high, which is not preferable. Furthermore, if the temperature of the maximum peak value is high, a low softening point substance is precipitated mainly during granulation, which is not preferable.
[0032]
In the present invention, for example, DSC-7 manufactured by Perkin Elmer is used for measuring the temperature of the maximum peak value of the low melting point substance. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium. As the sample, an aluminum pan was used, an empty pan was set for control, and the measurement was performed at a temperature rising rate of 10 ° C./min.
[0033]
Specific examples of the low melting point material include paraffin wax, polyolefin wax, Fischer tropish wax, amide wax, higher fatty acid, ester wax and derivatives thereof, or graft / block compounds thereof. The low softening point substance is preferably added to the toner in an amount of 5 to 30% by mass. If the addition is less than 5% by mass, sufficient toner fixing properties cannot be obtained. If the addition exceeds 30% by mass, toner particles are likely to coalesce during granulation even in the production by polymerization, and the particle size distribution is wide. The toner is easily generated and is not suitable for the present invention.
[0034]
As a specific method for embedding the low softening point substance, the polarity of the material in the aqueous medium is set to be smaller for the low softening point substance than the main monomer, and a small amount of a resin or monomer having a large polarity. By adding the above, it is possible to obtain a toner having a so-called core / shell structure in which a low softening point substance is coated with an outer shell resin. Toner particle size distribution control and particle size control can be done by changing the type and amount of the water-insoluble inorganic salt or protective colloid dispersant, mechanical conditions such as rotor peripheral speed, number of passes, etc. The toner of the present invention having a predetermined particle size distribution can be obtained by controlling the stirring conditions such as the shape of the stirring blades, the container shape, or the solid content concentration in the aqueous solution.
[0035]
As a specific method for measuring the tomographic plane of the toner in the present invention, a cured product obtained by sufficiently dispersing the toner in a room temperature curable epoxy resin and curing it in an atmosphere at a temperature of 40 ° C. for 2 days is used. After dyeing with ruthenium tetroxide and, if necessary, osmium tetroxide, using a microtome equipped with diamond teeth, a flaky sample was cut out and the tomographic morphology of the toner was measured using a transmission electron microscope (TEM) The observation was performed. In the present invention, it is preferable to use a ruthenium tetroxide dyeing method in order to provide a contrast between materials by utilizing a slight difference in crystallinity between the low softening point substance used and the resin constituting the outer shell. .
[0036]
Examples of the polymerizable monomer used in the present invention include styrene monomers such as styrene, o (m-, p-)-methylstyrene, m (p-)-ethylstyrene; methyl (meth) acrylate, Ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, ( (Meth) acrylic acid ester monomers such as 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate; butadiene, isoprene, cyclohexene, (meth) acrylonitrile, acrylic acid An ene monomer such as amide is preferably used.
[0037]
These may be used alone or in general so that the theoretical glass transition temperature (Tg) described in the publication Polymer Handbook 2nd edition III-P139-192 (John Wiley & Sons) is 40-80 ° C. It is used by mixing the body appropriately. When the theoretical glass transition temperature is less than 40 ° C., there arises a problem in terms of storage stability of the toner and durability of the developer. On the other hand, when it exceeds 80 ° C., the fixing point is increased. In this case, the color toners are not sufficiently mixed and the color reproducibility is poor, and the transparency of the OHP image is remarkably lowered.
[0038]
The molecular weight of the outer shell resin of the toner having a core / shell structure is measured by GPC (gel permeation chromatography). As a specific GPC measurement method, a toner is previously extracted with a Soxhlet extractor for 20 hours with a toluene solvent, and then toluene is distilled off with a rotary evaporator. Further, the low softening point substance is dissolved. The shell resin is a sample obtained by adding an organic solvent that cannot be dissolved, such as chloroform, and thoroughly washing, and then filtering the solution soluble in THF (tetrahydrofuran) through a solvent-resistant membrane filter having a pore size of 0.3 μm. The column structure can connect Showa Denko A-801, 802, 803, 804, 805, 806, 807, and can measure molecular weight distribution using a standard polystyrene resin calibration curve. The number average molecular weight (Mn) of the obtained resin component is 5,000 to 1,000,000, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 2. Outer shell resins showing 100 are preferred for the present invention.
[0039]
In the present invention, when a toner having a core / shell structure is produced, 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. The polar resin is particularly preferably one containing no unsaturated group capable of reacting with the outer shell resin or monomer in the molecule. If a polar resin having an unsaturated group is included, a cross-linking reaction occurs with the monomer forming the outer shell resin layer. Particularly, as a full color toner, it has a very high molecular weight. Since it becomes disadvantageous, it is not preferable.
[0040]
In the present invention, an outermost resin layer may be further provided on the toner surface. The glass transition temperature of the outermost shell resin layer is designed to be higher than the glass transition temperature of the outer shell resin layer in order to further improve the blocking resistance, and is further crosslinked to such an extent that the fixing property is not impaired. Is preferred. Further, it is preferable that the outermost shell resin layer contains a polar resin or a charge control agent in order to improve chargeability.
[0041]
The method for providing the outermost shell layer is not particularly limited, and examples thereof include the following methods.
[0042]
(1) In the latter half of the polymerization reaction or after completion, if necessary, a monomer in which a polar resin, a charge control agent, a crosslinking agent or the like is dissolved or dispersed is added to the reaction system, and adsorbed on the polymer particles. A method of polymerizing by adding.
[0043]
(2) If necessary, emulsion-polymerized particles or soap-free polymerized particles composed of monomers containing a polar resin, a charge control agent, a crosslinking agent, etc. are added to the reaction system, and agglomerated on the surface of the polymerized particles. A method of fixing by heat or the like according to.
[0044]
(3) A method in which emulsion-polymerized particles or soap-free polymerized particles composed of a monomer containing a polar resin, a charge control agent, a crosslinking agent, etc. are mechanically fixed to the toner particle surface as needed.
[0045]
As the colorant used in the present invention, carbon black, a magnetic material, and a yellow / magenta / cyan colorant shown below are used as a black colorant, and those which are toned in black are used.
[0046]
As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, etc. are preferably used.
[0047]
As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254 and the like are preferably used.
[0048]
As the cyan colorant used in the present invention, a copper phthalocyanine compound and a derivative thereof, 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 are preferably used.
[0049]
These colorants can be used alone or in combination, and further in a solid solution state.
[0050]
In the case of a color toner, the colorant used in the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin. When a magnetic material is used as the black colorant, 40 to 150 parts by mass are added to 100 parts by mass of the resin, unlike other colorants.
[0051]
As the charge control agent used in the present invention, known ones can be used. In the case of a color toner, in particular, it is colorless, the charging speed of the toner is fast, and a constant charge amount is stably maintained. A charge control agent capable of Furthermore, a charge control agent having no polymerization inhibition and no solubilized product in an aqueous system is particularly preferable.
[0052]
Specific examples of the negative compound include salicylic acid, naphthoic acid, dicarboxylic acid metal compound, sulfonic acid, polymer compound having carboxylic acid in the side chain, boron compound, urea compound, silicon compound, calixarene, etc. As the positive system, a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, an imidazole compound and the like are preferably used.
[0053]
The amount of the charge control agent used is preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the resin. However, in the present invention, it is not essential to add a charge control agent. When a two-component development method is used, friction charging with a carrier is used, and even when a non-magnetic one-component blade coating development method is used. By actively utilizing frictional charging with the blade member or the sleeve member, it is not always necessary to include a charge control agent in the toner.
[0054]
Examples of the polymerization initiator used in the present invention include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, and 1,1′-azobis (cyclohexane). -1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo-based polymerization initiators such as azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, Peroxide-based polymerization initiators such as cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy-2-ethylhexanoate are used.
[0055]
Although the addition amount of the said polymerization initiator changes with the target degree of polymerization, generally 0.5-20 mass% is added and used with respect to a monomer. The kind of the initiator is slightly different depending on the polymerization method, but is used alone or in combination with reference to the 10-hour half-life temperature. In order to control the degree of polymerization, a known crosslinking agent, chain transfer agent, polymerization inhibitor and the like can be further added and used.
[0056]
When suspension polymerization is used as the toner production method of the present invention, as a dispersant to be used, for example, as an inorganic oxide, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, Examples thereof include magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, magnetic substance, and ferrite. As the organic compound, for example, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, starch and the like are used by being dispersed or dissolved in an aqueous phase. These dispersants are preferably used in an amount of 0.2 to 10.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.
[0057]
Commercially available dispersants may be used as they are, but in order to obtain dispersed particles having a fine and uniform particle size, the inorganic compound can be produced in a dispersion medium under high-speed stirring. For example, in the case of tricalcium phosphate, a preferred dispersant for the suspension polymerization method can be obtained by mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution under high-speed stirring. Moreover, you may use 0.001-0.1 mass part surfactant together for refinement | miniaturization of these dispersing agents.
[0058]
Specifically, commercially available nonionic, anionic and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pendadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, stearin Potassium acid, calcium oleate and the like are preferably used.
[0059]
A specific toner production method of the present invention includes a release agent composed of a low softening substance, a colorant, a charge control agent, a polymerization initiator, and other additives in a monomer, a homogenizer, an ultrasonic disperser, and the like. The monomer composition uniformly dissolved or dispersed by the above method is dispersed in a granulation container containing a stirrer as shown in FIG. 1 or FIG. 2 containing a dispersion stabilizer.
[0060]
The granulation is stopped when the droplets made of the monomer composition have the desired toner particle size. Thereafter, stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. Polymerization is carried out at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C.
[0061]
Further, the temperature may be raised in the latter half of the polymerization reaction, and further, in order to remove unreacted polymerizable monomers, by-products, etc., the aqueous medium may be partially distilled off after the latter half of the reaction or after completion of the reaction. Good. After completion of the reaction, the produced toner particles are recovered by washing and filtration and dried. In the suspension polymerization method, it is usually preferable to use 300 to 3,000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer system.
[0062]
The external additive used for the purpose of imparting various toner characteristics preferably has a particle size of 1/10 or less of the weight average diameter of the toner particles from the viewpoint of durability when added to the toner. The particle size of the additive means the average particle size obtained by observing the surface of the toner particles with an electron microscope. As the external additive, for example, the following are used.
[0063]
Metal oxide (aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, zinc oxide, etc.), nitride (silicon nitride, etc.), carbide (silicon carbide, etc.), metal salt (sulfuric acid) Calcium, barium sulfate, calcium carbonate, etc.), fatty acid metal salts (zinc stearate, calcium stearate, etc.), carbon black, silica, etc. These external additives are used in an amount of 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of toner particles. These external additives may be used alone or in combination. Each of them is more preferably hydrophobized.
[0064]
The average particle size and particle size distribution of the toner can be measured by various methods such as Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter). In the present invention, Coulter Counter TA-II (Coulter Company) And an interface for outputting the number distribution and volume distribution (manufactured by Nikka) and a PC9801 personal computer (manufactured by NEC) are connected, and 1% NaCl aqueous solution is prepared using first-grade sodium chloride as the electrolyte solution. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used.
[0065]
As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the aqueous electrolyte solution, and 2 to 20 mg of a measurement sample is further added. The electrolyte solution in which the sample is suspended is dispersed for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number of toners of 2 μm or more are measured using the Coulter counter TA-II with a 100 μm aperture as an aperture. The volume distribution and the number distribution were calculated. Then, the volume-based weight average particle diameter (D _Four : The median value of each channel is the representative value of the channel) and the weight variation coefficient (S _Four ), The number average length average particle diameter (D ₁ ) And number variation coefficient (S ₁ )
[0066]
The image density is a numerical value obtained by measuring (5 mm square, 5 mm round, solid black) with a Macbeth densitometer (manufactured by Macbeth).
[0067]
【Example】
Hereinafter, the present invention will be described in more detail with specific examples and comparative examples.
[0068]
<Example 1>
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0069]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0070]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0071]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.1, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 25
Met.
[0072]
In addition, when the flow direction of the fluid at this time was confirmed with a high-speed video camera (Kodak Co., Ltd., Ekta Promotion Analyzer HS4540), as shown in FIG. It was confirmed.
[0073]
In addition, immediately after the polymerizable monomer composition was put into the granulation container, the inside of the granulation container was confirmed with the high-speed video camera, and the polymerizable monomer composition was smoothly mixed into the aqueous medium. I was able to confirm.
[0074]
Ten minutes after charging the polymerizable monomer composition, the stirring apparatus was stopped and transferred to a polymerization tank equipped with a paddle stirring blade. In the polymerization tank, 60 ° C, N ₂ Under the atmosphere, the reaction was performed for 10 hours while stirring with a paddle stirring blade. After completion of the polymerization reaction, the residual monomer was distilled off under reduced pressure. After cooling, hydrochloric acid was added to dissolve calcium phosphate, followed by filtration, washing with water and drying to obtain colored suspended particles.
[0075]
When the particle size distribution of the colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 6.5 μm and the number variation coefficient was 28%.
[0076]
Where the number variation coefficient is
Number variation coefficient = [S / D ₁ ] × 100
Where S represents the standard deviation in the number distribution of toner particles, and D ₁ Indicates the number average diameter (μm) of the toner particles. That is, the smaller the coefficient of variation, the sharper the particle size distribution of the toner particles, and a larger value indicates a broader particle size distribution.
[0077]
Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.
[0078]
The specific surface area by the BET method is 200 m with respect to 100 parts by mass of the obtained particles. ² The suspension polymerization toner 1 was obtained by externally adding 1.5 parts by mass of hydrophobic silica having a / g concentration. 95 parts by mass of an acrylic-coated ferrite carrier was mixed with 5 parts by mass of the toner to obtain a developer. When this developer was used to evaluate the image output of 5,000 continuous images using a Canon full-color copying machine CLC500, a good image was obtained with no fogging and stable image density.
[0079]
<Example 2>
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0080]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0081]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0082]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.1, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 74
Met.
[0083]
Thereafter, colored suspended particles were obtained in the same manner as in Example 1.
[0084]
When the particle size distribution of the colored suspension particles obtained was measured with a Coulter Multisizer, the weight average diameter was 6.6 μm and the number variation coefficient was 24%.
[0085]
Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.
[0086]
When the obtained particles were imaged and evaluated in the same manner as in Example 1, there was no fog, the image density was stable, and a good image was obtained.
[0087]
<Example 3>
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0088]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0089]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0090]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.1, d / D = 0.15
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 24
Met.
[0091]
Thereafter, colored suspended particles were obtained in the same manner as in Example 1.
[0092]
When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 6.7 μm and the number variation coefficient was 24%.
[0093]
Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.
[0094]
When the obtained particles were imaged and evaluated in the same manner as in Example 1, there was no fog, the image density was stable, and a good image was obtained.
[0095]
<Example 4>
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0096]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0097]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0098]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.1, d / D = 0.15
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 60
Met.
[0099]
Thereafter, colored suspended particles were obtained in the same manner as in Example 1.
[0100]
When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 6.7 μm and the number variation coefficient was 23%.
[0101]
Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.
[0102]
When the obtained particles were imaged and evaluated in the same manner as in Example 1, there was no fog, the image density was stable, and a good image was obtained.
[0103]
< Reference example 1 >
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0104]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0105]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0106]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.1, d / D = 0.15
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 17
Met.
[0107]
In addition, when the flow direction of the liquid at this time was confirmed with the high-speed video camera (the Kodak company make, Ekta promotion analyzer HS4540), as shown in FIG. 1, it was attracted | sucked from the upper direction and the downward direction of the stirring chamber, and was ejected from the side surface. However, the flow was weak and the stirring power was insufficient.
[0108]
Thereafter, colored suspended particles were obtained in the same manner as in Example 1.
[0109]
When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 6.5 μm and the number variation coefficient was 32%.
[0110]
Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.
[0111]
When the obtained particles were imaged and evaluated in the same manner as in Example 1, there was no fog, the image density was stable, and a good image was obtained.
[0112]
< Reference example 2 >
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0113]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0114]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0115]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.1, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 90
Met.
[0116]
Thereafter, colored suspended particles were obtained in the same manner as in Example 1.
[0117]
When the particle size distribution of the colored suspension particles obtained was measured with a Coulter Multisizer, the weight average diameter was 6.9 μm and the number variation coefficient was 25%.
[0118]
Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.
[0119]
When the obtained particles were imaged and evaluated in the same manner as in Example 1, there was a slight problem in fog and image density, but the level was satisfactory for the product. When this toner was observed with an electron microscope (SEM), some ultrafine particles appeared when stirring was excessive. It is thought that the ultrafine particles not detected by the Coulter Multisizer had some influence on the image.
[0120]
<Example 5 >
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0121]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0122]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0123]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.06, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 25
Met.
[0124]
In addition, when the flow direction of the liquid at this time was confirmed with the high-speed video camera (the Kodak company make, Ekta promotion analyzer HS4540), as shown in FIG. However, the suction from the lower side in FIG. 1 was weakly observed.
[0125]
Thereafter, colored suspended particles were obtained in the same manner as in Example 1.
[0126]
When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 6.7 μm and the number variation coefficient was 32%.
[0127]
Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.
[0128]
When the obtained particles were imaged and evaluated in the same manner as in Example 1, some problems were caused in fog and image density, but they were at a level with no product problems.
[0129]
<Example 6 >
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0130]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0131]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0132]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.4, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 25
Met.
[0133]
In addition, when the flow direction of the liquid at this time was confirmed with a high-speed video camera (Kodak Co., Ltd., Ekta Promotion Analyzer HS4540), as shown in FIG. This was clearly confirmed, but the free liquid level in the granulation vessel was disturbed and vortex was observed on the liquid level.
[0134]
Further, immediately after the polymerizable monomer composition was put in the granulation container, the inside of the granulation container was confirmed with the high-speed video camera, and as a result, the time for the polymerizable monomer composition to mix in the aqueous medium was determined. It took a little time compared to Example 1.
[0135]
Thereafter, colored suspended particles were obtained in the same manner as in Example 1.
[0136]
When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 6.9 μm and the number variation coefficient was 36%.
[0137]
Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.
[0138]
When the obtained particles were imaged and evaluated in the same manner as in Example 1, some problems were caused in fog and image density, but they were at a level with no product problems.
[0139]
<Example 7 >
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0140]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0141]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0142]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.8, l / L = 0.1, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 25
Met.
[0143]
Thereafter, colored suspended particles were obtained in the same manner as in Example 1.
[0144]
When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 6.6 μm and the number variation coefficient was 27%.
[0145]
Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.
[0146]
When the obtained particles were imaged and evaluated in the same manner as in Example 1, there was no fog, the image density was stable, and a good image was obtained.
[0147]
<Example 8 >
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0148]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0149]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0150]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 0.7, l / L = 0.1, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 25
Met.
[0151]
In addition, when the flow direction of the liquid at this time was confirmed with a high-speed video camera (Kodak Co., Ltd., Ekta Promotion Analyzer HS4540), as shown in FIG. This was clearly confirmed, but the free liquid level in the granulation vessel was disturbed and vortex was observed on the liquid level.
[0152]
Further, immediately after the polymerizable monomer composition was put in the granulation container, the inside of the granulation container was confirmed with the high-speed video camera, and as a result, the time for the polymerizable monomer composition to mix in the aqueous medium was determined. It took a little time compared to Example 1.
[0153]
Thereafter, colored suspended particles were obtained in the same manner as in Example 1.
[0154]
When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 6.6 μm and the number variation coefficient was 34%.
[0155]
Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.
[0156]
When the obtained particles were imaged and evaluated in the same manner as in Example 1, some problems were caused in fog and image density, but they were at a level with no product problems.
[0157]
<Example 9 >
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0158]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0159]
・ (Monomer) 78 parts by mass of styrene
・ (Monomer) 22 parts by mass of n-butyl acrylate
・ Magnetic (Silane coupling agent treatment) 90 parts by mass
・ (Negative charge control agent) 3 parts by mass of iron complex of monoazo dye
・ (Polar resin) Saturated polyester 4 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Releasing agent) ester wax [melting point: 70 ° C.] 4 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). To this was dissolved 3 parts by mass of t-butylperoxydiethylhexanoate as a polymerization initiator to prepare a polymerizable monomer composition.
[0160]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.1, d / D = 0.15
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 35
Met.
[0161]
In addition, when the flow direction of the liquid at this time was confirmed with the high-speed video camera (the Kodak company make, Ekta promotion analyzer HS4540), as shown in FIG. 1, it was attracted | sucked from the upper direction and the downward direction of the stirring chamber, and was ejected from the side surface. Was clearly confirmed.
[0162]
In addition, immediately after the polymerizable monomer composition was put into the granulation container, the inside of the granulation container was confirmed with the high-speed video camera, and the polymerizable monomer composition was smoothly mixed into the aqueous medium. I was able to confirm.
[0163]
Ten minutes after charging the polymerizable monomer composition, the stirring apparatus was stopped and transferred to a polymerization tank equipped with a paddle stirring blade. In the polymerization tank, the temperature is raised to 80 ° C. and N ₂ Under the atmosphere, the reaction was performed for 6 hours while stirring with a paddle stirring blade. After completion of the polymerization reaction, the residual monomer was distilled off under reduced pressure. After cooling, hydrochloric acid was added to dissolve calcium phosphate, followed by filtration, washing with water and drying to obtain colored suspended particles.
[0164]
When the particle size distribution of the colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 6.8 μm and the number variation coefficient was 26%.
[0165]
Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.
[0166]
To the obtained magnetic toner particles, 1.2% by mass of dry silica hydrophobized with silicone oil and hexamethyldisilazane is added to the obtained magnetic toner particles, and mixed with a mixer to form a developer. Got.
[0167]
When this developer was used to evaluate 5,000 continuous images with a laser beam printer 5Si manufactured by Hewlett-Packard, there was no fog, the image density was stable, and a good image was obtained.
[0168]
<Example 10 >
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0169]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0170]
・ (Monomer) 78 parts by mass of styrene
・ (Monomer) 22 parts by mass of n-butyl acrylate
・ Magnetic (Silane coupling agent treatment) 90 parts by mass
・ (Negative charge control agent) Monoazo dye iron complex 1 part by mass
・ (Polar resin) Saturated polyester 4 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Releasing agent) ester wax [melting point: 70 ° C.] 4 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). To this was dissolved 3 parts by mass of t-butylperoxydiethylhexanoate as a polymerization initiator to prepare a polymerizable monomer composition.
[0171]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.1, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 74
Met.
[0172]
When the particle size distribution of the colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 6.8 μm and the number variation coefficient was 26%.
[0173]
Further, when the toner tomographic plane was observed, a core / shell structure was confirmed.
[0174]
When the obtained particles were imaged and evaluated in the same manner as in Example 11, there was no fog, the image density was stable, and a good image was obtained.
<Comparative Example 1>
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0175]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0176]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0177]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.1, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 110
Met.
[0178]
Thereafter, the operation was scheduled to be performed for 10 minutes in the same manner as in Example 1, but since the noise was generated in the stirring blade from the middle, the operation was stopped. After that, when the stirring device was disassembled and the stirring blade 4 was inspected, countless damage was confirmed. This is thought to be due to the fact that the stirring force of the stirrer continued to be excessive, which caused a lot of cavitation at the tip of the stirring blade, resulting in erosion due to this bubble breakage and damaging the surface of the stirring blade. .
[0179]
<Comparative example 2>
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0180]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0181]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0182]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.1, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 10
Met.
[0183]
In addition, when the flow direction of the liquid at this time was confirmed visually with a high-speed video camera (manufactured by Kodak Corporation, Ekta Promotion Analyzer HS4540), suction from above and below was weak, and the liquid in the granulation vessel was clearly stirred. However, it was observed that the polymerizable monomer composition was retained in the upper part of the granulation container at the liquid surface. Thereafter, colored suspended particles were obtained in the same manner as in Example 1.
[0184]
When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 9.7 μm, the number variation coefficient was 46%, and the particle size distribution was clearly broad.
[0185]
When the obtained particles were imaged and evaluated in the same manner as in Example 1, fogging occurred from 1,000 durable sheets, and the image quality was also rough.
[0186]
<Comparative Example 3>
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0187]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0188]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0189]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 0.4, l / L = 0.65, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 81
Met.
[0190]
In addition, when the flow direction of the liquid at this time was confirmed visually with a high-speed video camera (manufactured by Kodak Co., Ltd., Ekta Promotion Analyzer HS4540), the liquid free surface in the granulation container was disturbed by suction from the upper part of the stirring chamber. It was confirmed that a lot of cavitation occurred around the stirring device. Thereafter, colored suspended particles were obtained in the same manner as in Example 1.
[0191]
When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 9.5 μm, the number variation coefficient was 46%, and the particle size distribution was clearly broad.
[0192]
When the obtained particles were imaged and evaluated in the same manner as in Example 1, fogging occurred from 1,000 durable sheets, and the image quality was also rough.
[0193]
<Comparative example 4>
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0194]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0195]
・ (Monomer) 170 parts by mass of styrene
・ (Monomer) 30 parts by mass of n-butyl acrylate
(Colorant) C.I. I. Pigment Red 122 10 parts by mass
・ (Charge control agent) Salicylic acid metal compound 3 parts by mass
・ (Polar resin) Saturated polyester 20 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Release agent) Ester wax [melting point: 70 ° C.] 25 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in this as a polymerization initiator to prepare a polymerizable monomer composition.
[0196]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 2.1, l / L = 0.03, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 10
Met.
[0197]
In addition, when the flow direction of the liquid at this time was confirmed visually with a high-speed video camera (manufactured by Kodak Corporation, Ekta Promotion Analyzer HS4540), suction from above and below was weak, and the liquid in the granulation vessel was clearly stirred. However, it was observed that the polymerizable monomer composition was retained in the upper part of the granulation container at the liquid surface. Thereafter, colored suspended particles were obtained in the same manner as in Example 1.
[0198]
When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 10.4 μm, the number variation coefficient was 48%, and the particle size distribution was clearly broad.
[0199]
When the obtained particles were imaged and evaluated in the same manner as in Example 1, fogging occurred from 1,000 durable sheets, and the image quality was also rough.
[0200]
<Comparative Example 5>
To 710 parts by mass of ion-exchanged water, 0.1 mol / liter-Na _Three PO _Four 450 parts by mass of the aqueous solution was added and heated to 60 ° C., and then stirred using the apparatus shown in FIG.
[0201]
To this, 1.0 mol / liter-CaCl ₂ 68 parts by mass of an aqueous solution was added, and a minute water-insoluble dispersant Ca _Three (PO _Four ) ₂ An aqueous dispersion medium containing was obtained.
[0202]
・ (Monomer) 78 parts by mass of styrene
・ (Monomer) 22 parts by mass of n-butyl acrylate
・ Magnetic (Silane coupling agent treatment) 90 parts by mass
・ (Negative charge control agent) Monoazo dye iron complex 1 part by mass
・ (Polar resin) Saturated polyester 4 parts by mass
[Acid value 10 mgKOH / g, peak molecular weight: 7,500]
・ (Releasing agent) ester wax [melting point: 70 ° C.] 4 parts by mass
The prescription was heated to 60 ° C., and uniformly dissolved or dispersed using a dissolution tank (with a stirrer). To this was dissolved 3 parts by mass of t-butylperoxydiethylhexanoate as a polymerization initiator to prepare a polymerizable monomer composition.
[0203]
The polymerizable monomer composition is charged into the aqueous dispersion medium, and the temperature is 60 ° C., N ₂ The polymerizable monomer composition was granulated under an atmosphere. At this time, the specification of the apparatus shown in FIG.
L / D = 1.3, l / L = 0.1, d / D = 0.25
The volume of liquid material V (m ^Three ) And use power P (kW) of the stirring device
P / V = 10
Met.
[0204]
In addition, when the flow direction of the liquid at this time was confirmed visually with a high-speed video camera (manufactured by Kodak Corporation, Ekta Promotion Analyzer HS4540), suction from above and below was weak, and the liquid in the granulation vessel was clearly stirred. However, it was observed that the polymerizable monomer composition was retained in the upper part of the granulation container at the liquid surface.
[0205]
When the particle size distribution of the colored suspension particles was measured with a Coulter Multisizer, the weight average diameter was 10.0 μm, the number variation coefficient was 47%, and the particle size distribution was clearly broad.
[0206]
When the obtained particles were imaged and evaluated in the same manner as in Example 11, fogging occurred from 1,000 durable sheets and the image quality was also rough.
[0207]
[Table 1]

[0208]
【The invention's effect】
As described above, according to the production method of the present invention, the particle size distribution at the time of granulation of the polymerizable monomer composition can be sharpened, and finally no classification step is required. Even so, a toner with a high yield and a sharp particle size distribution can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an example of a granulating apparatus used in the production method of the present invention.
FIG. 2 is a cross-sectional view of the stirring device in FIG.
[Explanation of symbols]
1 Granulation container
2 Stirrer
3 Stirring shaft
4 stirring blades
5 screens
6 Stirring chamber
7 Jacket
8 Liquid level
9 Motor
10 Inverter
11 Ammeter

Claims (3)

In a toner production method including at least a toner particle granulation step and a polymerization step,
The toner particle granulation step is a step of granulating by dispersing a polymerizable monomer composition containing a polymerizable monomer in an aqueous dispersion medium containing a dispersion stabilizer in a granulation vessel. Yes,
In the granulation vessel, a stirring device having a high shearing force is provided,
The stirring device includes a stirring blade and a stirring chamber that rotate at a high speed,
Liquid containing the polymerizable monomer composition and the aqueous dispersion medium is sucked from above and below the stirring chamber, stirred at the stirring拌室, granulated by being ejected from the side of the stirring chamber Grain is done,
20 <P / V <80 between the volume V (m ³ ) of the liquid material present in the granulation container and the power P (kW) of the stirring device
Have the relationship
0.5 between the inner diameter D of the granulation vessel, the liquid level height L obtained from the inner diameter D and the volume V (m ³ ), and the distance l of the stirring device from the bottom of the granulation vessel. <L / D <2.0, 0.04 <l / L <0.6
Have the relationship
Between the diameter d of the stirring blade and the inner diameter D,
0.1 <d / D <0.3
A toner production method characterized by the following relationship:   The toner production method according to claim 1, wherein the toner has a core / shell structure.   The toner production method according to claim 2, wherein a main component of the core part is a low softening point substance having a melting point of 40 to 90 ° C.

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