JP2011128487A - Heat treatment apparatus for toner and method of producing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat treatment apparatus for toner, along with a method of producing the toner, for obtaining toner particles having a sharp distribution of grain size without having coarse particles or toner fine powder. <P>SOLUTION: The heat treatment apparatus for the toner includes: a toner treatment space, which is substantially cylindrical; a source material feeder, which is disposed above a hot air feeder and supplies a source toner to the toner treatment space; a hot air feeder, which supplies hot air to the toner treatment space to heat-treat the source toner; at least one cool air feeder supplying cool air to the toner treatment space, which is disposed below the hot air feeder; and a recovery means, which is disposed underneath than the hot air feeder and the cool air feeder and which sucks and conveys the toner particles heat-treated in the toner treatment space. The hot air feeder and the cool air feeder supply air in a direction from a tangential direction of the toner treatment space in a horizontal cross section to the direction where the rotation of the source toner in the toner treatment space is maintained. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an apparatus for performing a heat treatment on a toner used in an image forming method such as an electrophotographic method, an electrostatic recording method, an electrostatic printing method, or a toner jet recording method, and production of toner using the device. Regarding the method.

  In order to obtain a toner having an appropriate degree of circularity, an apparatus has been proposed in which a pulverized toner is subjected to a heat treatment to appropriately spheroidize the toner. However, in the conventional thermal spheronization device, since the amount of heat received by the position through which the toner particles pass varies, it is difficult to uniformly treat the toner particles.

  In order to solve the above problems, a thermal spheronization apparatus having a configuration in which a raw material supply unit is provided at the center of the apparatus and a hot air supply unit is provided outside the raw material supply unit has been proposed (see Patent Documents 1 and 3). Further, in order to uniformly perform the heat treatment of the toner particles, a thermal spheronization device that performs heat treatment by swirling the airflow in the apparatus has also been proposed. (See Patent Document 2)

JP 2004-189845 A Japanese Patent Publication No. 3-52858 JP 2004-276016 A

  However, the thermal spheronization device described in Patent Document 1 needs to provide a plurality of raw material injection nozzles, which increases the size of the device. Moreover, since more compressed gas is required for raw material supply, it is not preferable also in terms of manufacturing energy. In addition, since the linear injection is performed on the annular hot air, a loss occurs in the processing portion, which is inefficient in increasing the processing amount.

  Further, when the present inventors examined the thermal spheronization device described in Patent Document 2, the toner was not sufficiently dispersed, and an increase in coarse particles due to toner coalescence was confirmed. In addition, when the processing amount was increased, the heat treatment efficiency for the toner decreased rapidly, and the heat-treated toner and the untreated toner were mixed. This is because the raw toner supply unit is installed in the compressed air supply unit, and the raw toner is not very dispersed in the apparatus, so that the instantaneous heat treatment is performed in a narrow range. Conceivable.

  Further, in the thermal spheronization device described in Patent Document 3, when the members in the device receive heat and store heat, the toner is fused to the stored members, and stable production may not be possible, and toner productivity may be unfavorable. .

  In recent years, toners used in image forming apparatuses have become so-called polymerized toners using techniques such as suspension polymerization and emulsion polymerization. These polymerized toners have a high degree of circularity. There are many things. However, these toners often cause cleaning difficulties.

  In recent years, it has been found that an average of 0.960 or more of toner to be provided is necessary in an image forming apparatus aimed at improving low-temperature fixability due to further interest in high image quality and energy saving. More preferably, the average circularity is 0.970 or more.

  However, it has also been found that if the frequency of the circularity of 0.990 or more in the circularity distribution of the toner provided exceeds 35%, a cleaning failure occurs. This is because toner in a more spherical state tends to slip through the cleaning blade. In order to prevent this slip-through, it is possible to take measures by increasing the contact pressure of the cleaning blade, but there is a limit because of adverse effects such as an increase in the rotational torque of the drum and wear of the cleaning blade.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a toner heat treatment apparatus and a toner manufacturing method for obtaining toner particles having few coarse particles and fine toner particles and having a sharp particle size distribution. Another object of the present invention is to provide a toner heat treatment apparatus and a toner manufacturing method for obtaining toner particles having an appropriate circularity distribution of toner particles and a sharp circularity distribution.

  The present invention is a toner heat treatment apparatus having a raw material supply means, a hot air supply means, a toner processing space, and a recovery means, wherein the toner processing space has a substantially cylindrical shape, and the raw material supply means is the hot air supply means. The raw toner is supplied to the toner processing space from a tangential direction in the horizontal cross section of the toner processing space, and the hot air supply means supplies hot air to the toner processing space in order to heat-treat the raw toner. At least one cool air supply means for supplying cool air to the toner processing space is provided below the hot air supply means, and the recovery means is provided below the hot air supply means and the cold air supply means, The toner particles heat-treated in the toner processing space are sucked and conveyed, and the hot air supply means and the cold air supply means are in a tangential direction in a horizontal cross section of the toner processing space and in the toner processing space. Regarding heat treatment apparatus of the toner and supplying the wind direction to maintain the turning of the raw material toner between.

  According to the present invention, toner particles having a sharp particle size distribution with few coarse particles and fine toner powder can be obtained. In addition, toner particles in which the circularity distribution of the toner particles is in an appropriate range and the circularity distribution is sharp can be obtained.

The perspective view of the heat processing apparatus of this invention Diagram explaining spheroidization mechanism by heat treatment equipment Diagram showing circularity distribution Relational diagram of 0.990 or more with respect to average circularity Sectional perspective view of the heat treatment apparatus of Example 4 Partial sectional view of the heat treatment apparatus of Comparative Example 1 Partial sectional view of the heat treatment apparatus of Comparative Example 2

In the present invention, coarse particles, fine particles, particles of 2.0 μm or less and raw material toner in the toner are defined as follows.
Coarse particles: Particle group fine particles of about twice or more of toner weight average diameter (D4): Particle groups of about ½ times or less of toner weight average diameter (D4) Particles of 2.0 μm or less: Flow type particle image analyzer Particle group raw material toner of 2.0 μm or less measured by “FPIA-3000 type” (manufactured by Sysmex Corporation): toner particles before heat treatment supplied to a heat treatment apparatus The present inventors control the sphericity of the toner In order to increase productivity, it is important to suppress the coalescence phenomenon such as adhesion and fusion that occurs between toner particles. I found it. Further, it was determined that it is important for the toner heat treatment apparatus to uniformly disperse the raw material toner and control the temperature distribution in the apparatus.

  The toner heat treatment apparatus of the present invention achieves the average circularity of the toner so as to improve the transferability, and enables the heat treatment without increasing the ratio of the high circularity product that deteriorates the cleaning property. In order to ensure good transferability, the average circularity of the heat-treated toner is preferably 0.960 or more. Furthermore, it is preferably 0.965 or more. Further, when the residual toner is removed from the photoreceptor using a cleaning member such as a blade, it is preferable to set the particle content at which the circularity is 0.990 or more to 35% or less. Furthermore, it is preferably 30% or less.

  The heat treatment apparatus of the present invention will be described. 1A and 1B are views showing an example of a heat treatment apparatus for toner according to the present invention. FIG. 1A shows the appearance of the heat treatment apparatus, and FIG. 1B shows the internal structure of the heat treatment apparatus.

  In the heat treatment apparatus shown in FIG. 1, the toner processing space has a substantially cylindrical shape, and a raw material supply means (8), a cold air supply means 1 (3), and a hot air supply means (2) are provided in order from the top.

  Further, a cold air supply means 2 (4) and a cold air supply means 3 (5) are provided below the hot air supply means (2), and a cylindrical pole from the lowest part of the apparatus to the upper part of the apparatus is provided at the center of the apparatus. (14) is provided, and an outlet for cold air is provided at the top of the pole (14).

  The raw toner supplied to the raw material supply means (8) is accelerated by the compressed gas supplied from the compressed gas supply means (not shown) and enters the toner processing space in the apparatus from the outlet of the raw material supply means (8). . The raw material supply means (8) is configured to supply the raw material toner to the toner processing space from the tangential direction with respect to the horizontal cross section of the toner processing space. By supplying the raw material toner in this way, the raw material toner smoothly rotates in the toner processing space, and the toner raw material is easily dispersed, thereby preventing the toner particles from being coalesced. The raw material supply means (8) may be configured to supply the raw toner from a plurality of locations in the horizontal direction.

  The cold air supply means 1 (3), the hot air supply means (2), the cold air supply means 2 (4), and the cold air supply means 3 (5) maintain the rotation of the raw material toner supplied from the raw material supply means (8), respectively. In the direction and from the tangential direction in the horizontal cross section of the toner processing space. The cold air supply means and the hot air supply means may be configured to supply air from a plurality of locations in the horizontal direction.

  Furthermore, the direction in which the cool air supplied from the cool air supply port at the top of the pole (14) exits is configured to flow in a direction that maintains the swirling of the toner particles, hot air, and the like. For the pole (14) outlet, a slit shape, louver shape, perforated plate shape, mesh shape, or the like can be used.

  In the present invention, as in the heat treatment apparatus shown in FIG. 1, at least one or more cold air supply means for supplying cold air to the toner processing space is provided below the hot air supply means. Moreover, the present invention preferably further has a cold air supply means above the hot air supply means as in the heat treatment apparatus shown in FIG. With such a configuration, the raw material toner is prevented from being fused to the outlet portion of the raw material supply means, and the raw material toner smoothly turns in the toner processing space.

  The hot air supplied into the apparatus preferably has a temperature C (° C.) at the outlet of the hot air supply means (2) 100 ≦ C ≦ 450. If the temperature at the outlet of the hot air supply means (2) is within the above range, the toner particles can be uniformly spheroidized while preventing the toner particles from fusing and coalescing due to overheating. Become.

  The heat-treated toner is cooled by the cold air supply means 2 (4). At this time, cold air may be introduced from the cold air supply means 3 (4) provided on the side surface of the main body of the apparatus for the purpose of controlling the temperature in the apparatus and controlling the surface state of the toner. The outlets of the cold air supply means 1 (3), the cold air supply means 2 (4) and the cold air supply means 3 (5) can use slit shapes, louver shapes, perforated plate shapes, mesh shapes, etc. The direction is along the wall.

  The temperature E (° C.) in the cold air supply means 1 (3), the cold air supply means 2 (4), the cold air supply means 3 (5) and the pole (14) is preferably −20 ≦ E ≦ 40. If the temperature in the cold air supply means is within the above range, the toner particles can be cooled appropriately, and the toner particles can be prevented from fusing or coalescing without impairing the uniform spheroidization process. can do.

  The cooled toner is collected through a collecting means (13) that is a discharge unit.

  The cooled toner particles are recovered through recovery means (13) having a toner discharge port. A blower (not shown) is provided on the downstream side of the collecting means (13), and is sucked and conveyed by the blower. The collecting means (13) is provided at the lowermost part of the apparatus and is configured to be horizontal to the outer peripheral part of the apparatus. The direction of connection of the discharge port is a direction in which the flow by the rotation from the upstream portion of the apparatus to the discharge port is maintained.

  In the heat treatment apparatus of the present invention, the relationship between the total amount QIN of the flow rate of the compressed gas, hot air and cold air supplied into the device and the air amount QOUT sucked by the blower is adjusted to satisfy the relationship of QIN ≦ QOUT. Is preferred. If QIN ≦ QOUT, the pressure in the apparatus becomes negative, so that the ejected toner particles are easily discharged out of the apparatus, and the toner particles can be prevented from receiving excessive heat. As a result, it is possible to prevent an increase in united toner particles and fusion within the apparatus.

  A process of making the toner particles spherical using the above-described configuration will be described with reference to FIG.

  The raw toner introduced from the raw material supply means (8) moves downward while turning around the outer periphery of the toner processing space in the apparatus. The cold air supply means 1 (3) provided below the raw material supply means (8) supplies the cold air in a direction to maintain the rotation of the raw toner, so that the rotation of the raw toner is further strengthened.

  In this state, the hot air supplied from the hot air supply means (2) is supplied in a direction to maintain the rotation of the raw toner, whereby the raw toner is heat-treated while rotating around the outer periphery of the toner processing space in the apparatus. Accordingly, toner particles having a large particle diameter pass through a flow path having a large turning radius, and toner particles having a small particle diameter pass through a flow path having a small turning radius. As a result, toner particles having a large particle size are heated for a long time, and toner particles having a small particle size are heated for a short time. Therefore, the toner particles are heat-treated with a heat amount corresponding to the size of the particle size. Is possible. In addition, since the direction of the airflow in the apparatus is uniform, the collision between the toner particles hardly occurs, and coalescence of the toner particles can be suppressed.

  The cold air supply means 2 (4), the cold air supply means 3 (5), and the pole (14) cool the heat-treated toner particles and prevent the toner particles from being fused in the apparatus. The collecting means (13) is provided so as to be collected while maintaining the swirling flow of the toner particles in the toner processing space.

  A conventional heat treatment apparatus is shown in FIG. In the apparatus shown in FIG. 7, when the raw material toner is injected into the apparatus, the injection port is often provided in the hot air, and the raw material toner is dispersed in the hot air by compressed air. However, in this configuration, the raw material toner is not sufficiently dispersed, and the amount of heat corresponding to the particle size of the toner particles cannot be applied unlike the heat treatment apparatus of the present invention. Further, regardless of the particle diameter of the toner particles, the amount of heat applied to the toner particles varies, and the mixture ratio of toner particles that are not sufficiently heat-treated increases. Increasing the amount of heat applied to reduce the mixing ratio of untreated toner particles increases the average circularity, but the ratio of toner particles having a circularity of 0.990 or more increases and the toner particles are coalesced. Will occur.

  FIG. 3A shows changes in the average circularity and circularity distribution of the toner particles when the toner particles are heat-treated using the heat treatment apparatus shown in FIG. FIG. 3B shows changes in the average circularity and circularity distribution of the toner particles when the toner particles are heat-treated using the heat treatment apparatus shown in FIG. When the raw toner having an average circularity of 0.940 is heat-treated so that the average circularity of the toner becomes 0.970 with the heat treatment apparatus shown in FIG. The frequency tends to increase (see FIG. 3B). Further, the difference between the average circularity value and the circularity indicating the peak in the circularity distribution is large. On the other hand, when heat treatment is performed using the heat treatment apparatus shown in FIG. 1, the peak position is not deviated from the value of the average circularity of the toner particles, and the frequency of toner particles having a circularity of 0.990 or more is also suppressed. (See FIG. 3A). In addition, when the heat treatment time is further shortened and the average circularity of the toner particles is suppressed to about 0.955, the use of the heat treatment apparatus shown in FIG. The shape of is sharp.

  Next, a procedure for manufacturing toner will be described.

  In the raw material mixing step, at least a resin, a colorant, and a wax are weighed and mixed as a raw material for the toner and mixed. The resin preferably contains a styrene copolymer and a resin having a polyester unit. The polyester unit means a part derived from polyester. Examples of the component constituting the polyester unit include divalent or higher alcohol monomer components and divalent or higher carboxylic acids, divalent or higher carboxylic acid anhydrides, and divalent or higher carboxylic acid esters. Known colorants and waxes are used. As the mixing apparatus, a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, and a Nauta mixer can be used.

  The mixed toner raw materials are further melt-kneaded to melt the resins and disperse the colorant and the like therein. In the melt-kneading step, for example, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. In recent years, single-screw or twin-screw extruders have become mainstream due to the advantage of being capable of continuous production, for example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd. A twin screw extruder manufactured by Kay Sea Kay, a co-kneader manufactured by Buss, etc. are generally used. Furthermore, the colored resin composition obtained by melt-kneading the toner raw material is cooled by a cooling process in which it is rolled with two rolls after cooling and kneading and cooled by water cooling or the like.

  Next, in the pulverization step, the colored resin composition is roughly pulverized by a crusher, a hammer mill, a feather mill, or the like, and further pulverized by a kryptron system manufactured by Kawasaki Heavy Industries, Ltd., a super rotor manufactured by Nisshin Engineering, or the like. The obtained toner particles are classified using a classifier such as an inertia classification type elbow jet (manufactured by Nippon Steel Mining Co., Ltd.), a centrifugal classification type turboplex (manufactured by Hosokawa Micron Co., Ltd.), or the like.

  Further, an external additive may be externally added to the toner particles. A predetermined amount of classified toner particles and external additives are blended, and a high-speed stirrer that gives shearing force to the powder, such as a Henschel mixer or a super mixer, is used as an external adder to stir and mix the toner particles. Additives are externally added. Known external additives such as silica and titanium oxide are used as the external additive.

  The surface modification using the heat treatment apparatus of the present invention is preferably performed after classification or after external addition treatment. When the raw material toner is supplied in a fixed amount to the heat treatment apparatus of the present invention, a constant supply machine FS type (manufactured by Powder Research Powtex) or Finetron FT (manufactured by Hosokawa Micron) can be used. The toner particles processed with the heat treatment apparatus of the present invention preferably have a weight average diameter (D4) of 4 μm or more and 12 μm or less.

  A method for measuring various physical properties of the toner will be described below.

<Measuring method of weight average particle diameter (D4) and number average particle diameter (D1)>
The weight average particle diameter (D4) and number average particle diameter (D1) of the toner are measured by a fine particle size distribution measuring apparatus “Coulter Counter Multisizer 3” (registered trademark, Beckman 2) Effective measurement channel number 25,000 using “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) and attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” for measurement condition setting and measurement data analysis Measurement was performed on the channel, and the measurement data was analyzed and calculated.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows.

  In the “Standard Measurement Method (SOM) Change Screen” of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter, Inc.) Set the value obtained using The threshold and noise level are automatically set by pressing the threshold / noise level measurement button. Also, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the aperture tube flash after measurement is checked.

  In the “pulse to particle size conversion setting screen” of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

  The specific measurement method is as follows.

  (1) About 200 ml of the electrolytic solution is placed in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the analysis software.

  (2) About 30 ml of the electrolytic aqueous solution is put in a glass 100 ml flat bottom beaker, and "Contaminone N" (nonionic surfactant, anionic surfactant, organic builder pH 7 precision measurement is used as a dispersant therein. About 0.3 ml of a diluted solution obtained by diluting a 10% by weight aqueous solution of a neutral detergent for washing a vessel (made by Wako Pure Chemical Industries, Ltd.) 3 times with ion-exchanged water is added.

  (3) Two oscillators with an oscillation frequency of 50 kHz are incorporated in a state where the phase is shifted by 180 degrees, and placed in a water tank of an ultrasonic dispersion device “Ultrasonic Disposition System Tetora 150” (manufactured by Nikka Ki Bios Co., Ltd.) having an electrical output of 120 W A fixed amount of ion-exchanged water is added, and about 2 ml of the above-mentioned Contaminone N is added to this water tank.

  (4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.

  (5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.

  (6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . Measurement is performed until the number of measured particles reaches 50,000.

  (7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. When the graph / volume% is set with the dedicated software, the “average diameter” on the analysis / volume statistics (arithmetic average) screen is the weight average particle size (D4), and the graph / number% is set with the dedicated software. The “average diameter” on the analysis / number statistic (arithmetic average) screen is the number average particle diameter (D1).

<Calculation method of fine powder amount>
The number-based fine powder amount (number%) in the toner is calculated as follows.

  For example, the number% of particles having a particle size of 4.0 μm or less in the toner is measured by the above-mentioned Multisizer 3, and (1) graph / number% is set with dedicated software, and the measurement result chart is displayed in number%. (2) Check “<” in the particle size setting portion on the format / particle size / particle size statistics screen, and enter “4” in the particle size input section below. Then, (3) when the analysis / count statistics (arithmetic mean) screen is displayed, the numerical value of the “<4 μm” display portion is the number% of particles of 4.0 μm or less in the toner.

<Calculation method of coarse powder amount>
The volume-based coarse powder amount (volume%) in the toner is calculated as follows.

  For example, the volume% of particles of 10.0 μm or more in the toner is measured by the above-mentioned Multisizer 3, and (1) graph / volume% is set with dedicated software, and the measurement result chart is displayed as volume%. (2) Check “>” in the particle size setting portion on the format / particle size / particle size statistics screen, and enter “10” in the particle size input section below. (3) When the analysis / volume statistics (arithmetic average) screen is displayed, the numerical value of the “> 10 μm” display portion is the volume% of particles of 10.0 μm or more in the toner.

<Measurement of average circularity of toner particles>
The average circularity of the toner particles is measured under a measurement / analysis condition at the time of calibration by a flow type particle image analyzer “FPIA-3000 type” (manufactured by Sysmex Corporation).

  As a specific measurement method, an appropriate amount of a surfactant, preferably an alkyl benzene sulfonate, is added to 20 ml of ion-exchanged water, and then 0.02 g of a measurement sample is added, and an oscillation frequency of 50 kHz and an electric output of 150 W is added. Dispersion treatment is performed for 2 minutes using a desktop type ultrasonic cleaner / disperser (for example, “VS-150” (manufactured by Velvo Crea Co., Ltd.)) to obtain a dispersion for measurement. It cools suitably so that it may become 10 to 40 degreeC.

  The flow type particle image analyzer equipped with a standard objective lens (10 ×) is used for measurement, and a particle sheath “PSE-900A” (manufactured by Sysmex Corporation) is used as the sheath liquid. The dispersion prepared in accordance with the above procedure is introduced into the flow type particle image analyzer, 3000 toner particles are measured in the total count mode in the HPF measurement mode, and the binarization threshold at the time of particle analysis is 85%. The analysis particle diameter is limited to a circle equivalent diameter of 2.00 μm or more and 200.00 μm or less, and the average circularity of the toner particles is obtained.

  In the measurement, automatic focus adjustment is performed using standard latex particles (for example, Duke Scientific 5200A diluted with ion-exchanged water) before the measurement is started. Thereafter, it is preferable to perform focus adjustment every two hours from the start of measurement.

  In this embodiment, a flow type particle image analyzer which has been issued a calibration certificate issued by Sysmex Corporation, which has been calibrated by Sysmex Corporation, has an analysis particle diameter of 2.00 μm in equivalent circle diameter. The measurement was performed under the measurement and analysis conditions when the calibration certificate was received, except that it was limited to 200.00 μm or less.

[Production of Toner Particle A]
Binder resin (polyester resin): 100 parts by mass (Tg 58 ° C., acid value 25 mgKOH / g, hydroxyl value 20 mgKOH / g, molecular weight: Mp5500, Mn2800, Mw50000)
・ C. I. Pigment Blue 15: 3: 5 parts by mass, 1,4-di-t-butylsalicylic acid aluminum compound: 0.5 parts by mass, Fischer-Tropsch wax: 5 parts by mass (manufactured by Nippon Seiwa Co., Ltd., trade name FT-100, melting point) 98 ° C)
After mixing the materials of the above formulation with a Henschel mixer (FM-75J type, manufactured by Mitsui Mining Co., Ltd.), a twin-screw kneader (PCM-30 type, manufactured by Ikekai Steel Co., Ltd.) set at a temperature of 130 ° C. ) At a feed amount of 10 kg / hr (kneaded material temperature at the time of discharge was about 150 ° C.). The obtained kneaded product was cooled, coarsely crushed with a hammer mill, and then finely pulverized with a mechanical pulverizer (T-250: manufactured by Turbo Kogyo Co., Ltd.) with a feed amount of 15 kg / hr, and the weight average particle diameter Is a toner finely pulverized product B-1 containing 55.6% by number of particles having a particle size of 4.0 μm or less and 0.8% by volume of particles having a particle size of 10.1 μm or more. .

  The obtained finely pulverized toner B-1 was classified by cutting a fine powder and a coarse powder at a feed amount of 4.2 kg / hr with a rotary classifier (TTSP100, manufactured by Hosokawa Micron Co., Ltd.). Toner particles A having a diameter of 5.6 μm, 25.6% by number of particles having a particle size of 4.0 μm or less, and 0.2% by volume of particles having a particle size of 10.1 μm or more were obtained.

  As a result of measuring the circularity of the toner particles A with FPIA 3000, the average circularity was 0.940, and the particle content of 2 μm or less was 11.0%. The ratio of particles having a circularity of 0.940 or less was 41.5% by number.

[Example 1]
The toner particles A were heat-treated using the apparatus shown in FIG. The inner diameter of the raw material supply means was Φ350 mm, the other inner diameter was Φ450 mm, and the outer diameter of the pole was Φ200.

  Using the apparatus configured as described above, the toner particles A were heat-treated so as to have an average circularity of 0.970.

The operating conditions at this time are: feed amount (F) = 15 kg / hr, hot air temperature (T1) = 175 ° C., hot air flow rate (Q1) = 7.0 m ³ / min, cold air 1 total amount (Q2) = 2.0 m ³ / Min, cold air 2 total amount (Q3) = 4.0 m ³ / min, cold air 3 total amount (Q4) = 2.0 m ³ / min, pole cold air total amount (Q5) = 0.5 m ³ / min, compressed gas air volume (IJ ) = 1.4 m ³ / min, blower air volume (Q6) = 23.0 m ³ / min, and the operation time was 1 hour.

  The particle size distribution of the heat-treated toner particles obtained at this time is such that the weight average diameter is 6.3 μm, the particle diameter is 4.0 μm or less is 26.1%, and 10.0 μm or more is 0.8% by volume. there were. Furthermore, the frequency of 0.990 or more in the frequency of circularity distribution was 24.6%.

  Next, the feed amount (F) was changed to 40 kg / hr, and heat treatment was performed without changing other operating conditions.

  As for the particle size distribution of the heat-treated toner particles obtained at this time, the weight average diameter is 6.4 μm, the particle diameter is 4.0 μm or less is 25.9% by number, and the particle size distribution is 10.0 μm or more and 3.5% by volume. there were. The average circularity was 0.966.

  Next, using the apparatus configured as described above, the toner particles A were heat-treated so as to have an average circularity of 0.955.

The operating conditions at this time are as follows: feed amount (F) = 15 kg / hr, hot air temperature (T1) = 155 ° C., hot air flow rate (Q1) = 7.0 m ³ / min, cold air 1 total amount ( ^{Q2) =} 2.0m 3 / min, cold air 2 total ^{(Q3) = 4.0m 3 / min} , cold air 3 total ^{(Q4) = 2.0m 3 / min} , Paul cool air amount (Q5) = 0.5m ³ / min, compressed gas flow rate (IJ) = 1.4 m ³ / min, blower flow rate (Q6) = 23.0 m ³ / min, and the operation time was 1 hour.

  As for the particle size distribution of the heat-treated toner particles obtained at this time, the weight average diameter is 6.3 μm, the particle diameter is 4.0 μm or less is 26.3% by number, and 10.0 μm or more is 0.6% by volume. there were. Furthermore, the frequency of 0.940 or less in the frequency of circularity distribution was 10.3%.

  Each operating condition is shown in Table 1.

  The toner particles obtained from each operating condition were evaluated according to the following criteria. The evaluation results are shown in Table 2.

(Evaluation criteria 1)
The frequency of toner particles having a circularity of 0.990 or more in the circularity distribution was determined.

A: Toner particles having a circularity of 0.990 or more are less than 30% B: Toner particles having a circularity of 0.990 or more are from 30% to less than 35% C: Toner particles having a circularity of 0.990 or more are 35 % (Evaluation criteria 2)
The increase amount of the toner particles of 10.0 μm or more when the treatment amount is increased as shown by the following formula was determined.
Increase amount of toner particles of 10.0 μm or more = (Volume% of toner particles of 10.0 μm or more when processed at a feed amount of 40 kg / hr) − (0.0 μm or more of processed toner particles at a feed amount of 15 kg / hr) Toner particle volume%)
A: Increase is 0 or more and less than 3.0 B: Increase is 3.0 or more and less than 5.0 C: Increase is 5.0 or more and less than 10.0 D: Increase is 10.0 or more and less than 15.0 E: Increase is 15.0 or more (Evaluation Criteria 3)
In the frequency of the circularity distribution of the toner particles heat-treated so that the average circularity becomes 0.955, the ratio of the particles whose circularity is equal to or less than the average circularity of the raw material toner is obtained and set as Ha. Then, a value (Z) obtained by dividing the obtained Ha by Ha of Comparative Example 1 described later was obtained.
A: Z is smaller than 1.0.
B: Z is 1.0 or more.
Similarly, the ratio (Z ′) to Ha of Comparative Example 2 described later was obtained.
A: Z ′ is smaller than 1.0.
B: Z ′ is 1.0 or more.

(Evaluation criteria 4)
The presence or absence of fusion in the apparatus was examined.
○: In-device fusion did not occur.
X: In-device fusion occurred.

[Example 2]
In this example, the apparatus used in Example 1 did not supply cold air from the pole.

  Using the apparatus configured as described above, the toner particles A were heat-treated so that the average circularity was 0.970. Next, the feed amount (F) was changed to 40 kg / hr, and the toner particles A were heat-treated without changing other operating conditions. Furthermore, the feed amount (F) was set to 15 kg / hr, and other operating conditions were changed, and the toner particles A were heat-treated so that the average circularity was 0.955.

  Each operating condition is shown in Table 1. Further, the toner particles obtained from the respective operating conditions were evaluated according to the same criteria as in Example 1. The evaluation results are shown in Table 2.

Example 3
In this example, the apparatus used in Example 1 was configured to have no pole.

  Using the apparatus configured as described above, the toner particles A were heat-treated so that the average circularity was 0.970. Next, the feed amount (F) was changed to 40 kg / hr, and the toner particles A were heat-treated without changing other operating conditions. Furthermore, the feed amount (F) was set to 15 kg / hr, and other operating conditions were changed, and the toner particles A were heat-treated so that the average circularity was 0.955.

  Each operating condition is shown in Table 1. Further, the toner particles obtained from the respective operating conditions were evaluated according to the same criteria as in Example 1. The evaluation results are shown in Table 2.

Example 4
Heat treatment was performed using an apparatus configured as shown in FIG. Compared with the apparatus used in Example 1, the apparatus shown in FIG. 5 has a structure in which no cool air supply means is provided above the hot air supply means and no pole is provided.

  Using the apparatus configured as described above, the toner particles A were heat-treated so as to have an average circularity of 0.970.

  Using the apparatus configured as described above, the toner particles A were heat-treated so that the average circularity was 0.970. Next, the feed amount (F) was changed to 40 kg / hr, and the toner particles A were heat-treated without changing other operating conditions. Furthermore, the feed amount (F) was set to 15 kg / hr, and other operating conditions were changed, and the toner particles A were heat-treated so that the average circularity was 0.955.

  Each operating condition is shown in Table 1. Further, the toner particles obtained from the respective operating conditions were evaluated according to the same criteria as in Example 1. The evaluation results are shown in Table 2.

[Comparative Example 1]
The toner particles were heat-treated using the apparatus shown in FIG. In the heat treatment apparatus, the raw material supply means (6 in the figure) is inserted into the hot air supply means (5 in the figure), and an outside air intake part (3 in the figure) is provided on the outer periphery of the hot air supply means. Further, the raw material toner is configured to be dispersed by colliding with a collision member (9 in the figure). In this apparatus, the hot air and the raw material toner are not configured to rotate.

Using the apparatus configured as described above, the toner particles A were heat-treated so that the average circularity was 0.970. Operating conditions of this time, the feed amount (F) = 15kg / hr, a hot air temperature = 300 ° C., hot air flow rate = 10.0 m ³ / min, cold = 10.0 m ³ / min, an injection flow rate = 3.0 m ³ / The min and operating time were 1 hour.

Next, the feed amount (F) was changed to 40 kg / hr, and the toner particles A were heat-treated without changing other operating conditions. Further, the toner particles A were heat-treated using the apparatus having the above-described configuration so that the average circularity was 0.955. Operating conditions of this time, the feed amount (F) = 15kg / hr, a hot air temperature = 250 ° C., hot air flow rate = 10.0 m ³ / min, cold = 10.0 m ³ / min, an injection flow rate = 3.0 m ³ / The min and operating time were 1 hour.

  Each operating condition is shown in Table 1. Further, the toner particles obtained from the respective operating conditions were evaluated according to the same criteria as in Example 1. The evaluation results are shown in Table 2.

  The reason why the toner particles of 10.0 μm or more increase is that the toner particle supply nozzle is inserted in the hot air, so that the heat is trapped at the nozzle outlet, so that the toner particles coalesce and coarse particles increase. It depends.

  When this comparative example is compared with an Example, since there are many hot-air flow rates, cold-air flow rates, and injection flow rates to supply and hot-air temperature is also high, it is unpreferable from the surface of manufacturing energy.

  Further, when the toner particles A are processed so as to have an average circularity of 0.970, the frequency of 0.990 or more in the circularity distribution is higher than that in the example. Further, when the toner particles A are processed so as to have an average circularity of 0.955, the frequency of 0.940 or less in the circularity distribution is higher than that in the example. This is because the hot air temperature is higher than that of the apparatus having the configuration of the embodiment, and the efficiency in spheroidizing the toner particles is low.

[Comparative Example 2]
The toner particles were heat-treated using the apparatus shown in FIG. The apparatus is configured to rotate the raw material toner in the raw material supply means (7 in the figure) and supply the raw toner into the hot air, and the hot air supply means (22 in the figure) has an air flow adjusting unit (see FIG. Medium 21) is provided.

Using the heat treatment apparatus, the toner particles A were heat-treated so that the average circularity was 0.970. Operating conditions of this time, the feed amount (F) = 15kg / hr, a hot air temperature = 250 ° C., hot air flow rate = 10.0 m ³ / min, cold = 10.0 m ³ / min, an injection flow rate = 2.5 m ³ / The min and operating time were 1 hour. Next, the feed amount (F) was changed to 40 kg / hr, and the toner particles A were heat-treated without changing other operating conditions. Furthermore, the feed amount (F) was set to 15 kg / hr, and other operating conditions were changed, and the toner particles A were heat-treated so that the average circularity was 0.955. Operating conditions of this time, the feed amount (F) = 15kg / hr, a hot air temperature = 220 ° C., hot air flow rate = 10.0 m ³ / min, cold = 10.0 m ³ / min, an injection flow rate = 2.5 m ³ / The min and operating time were 1 hour.

  Each operating condition is shown in Table 1. Further, the toner particles obtained from the respective operating conditions were evaluated according to the same criteria as in Example 1. The evaluation results are shown in Table 2.

  The reason why the toner particles of 10.0 μm or more increase is that the toner particle supply nozzle is inserted in the hot air, so that the heat is trapped at the nozzle outlet, so that the toner particles coalesce and coarse particles increase. It depends.

  Furthermore, since the swirl flow in the nozzle for injecting the raw material is actually poor in the effect of spreading so as to maintain the nozzle angle in the apparatus, it is difficult to make the sphere into a spherical shape unless the hot air volume or temperature is increased.

  Moreover, since the direction of the exit part of the hot air supply means is toward the axial center part, the spread of the raw material is hindered, and the turning radius remains small. Therefore, the classification effect by the swirling flow is also lost.

  When this comparative example is compared with an Example, since there are many hot-air flow rates, cold-air flow rates, and injection flow rates to supply, and hot-air temperature is also high, it is unpreferable from the surface of manufacturing energy. Further, when the toner particles A are processed so as to have an average circularity of 0.970, the frequency of 0.990 or more in the circularity distribution is higher than that in the example. Further, when the toner particles A are processed so as to have an average circularity of 0.955, the frequency of 0.940 or less in the circularity distribution is higher than that in the example.

DESCRIPTION OF SYMBOLS 1 Heat processing apparatus main body 2 Hot-air supply means 3 Cold-air supply means 1
4 Cold air supply means 2
5 Cold air supply means 3
8 Raw material supply means 13 Collection means 14 Pole

Claims (4)

A heat treatment apparatus for toner having raw material supply means, hot air supply means, toner processing space and recovery means,
The toner processing space has a substantially cylindrical shape,
The raw material supply means is provided above the hot air supply means, and supplies the raw toner to the toner processing space from the tangential direction in the horizontal cross section of the toner processing space,
The hot air supply means supplies hot air to the toner processing space to heat-treat the raw toner,
At least one or more cold air supply means for supplying cold air to the toner processing space is provided below the hot air supply means,
The recovery means is provided below the hot air supply means and the cold air supply means, and sucks and conveys the heat-treated toner particles in the toner processing space,
The hot air supply means and the cold air supply means supply air in a tangential direction in a horizontal section of the toner processing space and in a direction to maintain the rotation of the raw material toner in the toner processing space. apparatus.   The toner heat treatment apparatus according to claim 1, wherein a cold air supply unit is also provided above the hot air supply unit.   3. A cylindrical pole is provided at an axial center of the toner processing space, and cold air is supplied from the pole in a direction to maintain the rotation of the raw material toner in the toner processing space. The toner heat treatment apparatus as described.   A method for producing a toner having a heat treatment step of heat-treating at least a raw material toner, wherein the toner heat treatment apparatus according to any one of claims 1 to 3 is used, and the obtained toner has a weight average diameter. A method for producing a toner, wherein the toner size is 4 μm or more and 12 μm or less.

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