JP6633874B2 - Manufacturing method of toner - Google Patents

Description

  The present invention relates to a method for producing a toner for developing an electrostatic image.

As a method for producing a toner for developing an electrostatic image (hereinafter sometimes simply referred to as “toner”), the environmental load during production is reduced, and a toner having a small particle size and a sharp particle size distribution is easily obtained. Wet manufacturing methods are often used because of their advantages such as easy encapsulation.
The wet production method is a method for producing toner particles in a liquid medium. Production methods such as a suspension polymerization method, an emulsion polymerization method, a solution suspension method, and a dispersion polymerization method are carried out depending on a material constituting the toner particles and a desired toner particle shape.

In the wet production method, the adhesion of scale easily occurs in a container such as a storage container or a reaction container of the toner particle dispersion. The adhesion of the scale causes a yield loss and unintended mixing into the next batch or the like. In addition, a scale removing operation occurs, which causes a reduction in the operation rate.
Further, when a temperature controller is provided in the container, if scale adheres to the vicinity of the temperature controller, the heat transfer performance is reduced, and the temperature rise / fall rate and temperature control become unstable. When the treatment performed in the vessel is a polymerization reaction, it is particularly important to prevent adhesion to the temperature controller. If scale adheres to the temperature controller, heat transfer is hindered, so that the rate of temperature rise and fall is delayed as the batches are stacked, and the temperature control becomes unstable because a desired temperature cannot be maintained. In the polymerization reaction, the temperature affects the polymerization rate, and if the polymerization rate is not uniform between different batches, it is impossible to obtain toner particles having different molecular weights of the generated toner and stable thermal characteristics.

For this reason, a technique for suppressing the adhesion of scale to the inner wall of the container or a technique for cleaning the attached scale has been proposed in a wet production method.
For example, as a technique for suppressing scale adhesion, a technique of performing a polymerization reaction in the presence of a substance having a vapor pressure higher than a polymerizable monomer by a certain amount or more is disclosed (see Patent Document 1). Further, a technique is disclosed in which a liquid containing a poorly water-soluble inorganic compound as a scale inhibitor is applied to the inner wall of a container to carry out a polymerization step, and the contents of the container are discharged and then contacted with an aqueous solution having a pH of 9 or more (patented). Reference 2).

  Further, as a technique for cleaning the attached scale, there is disclosed a technique of removing a substance attached to an inner wall surface of a manufacturing apparatus with high-pressure water after discharging a treatment liquid from the manufacturing apparatus (see Patent Document 3). Furthermore, there is disclosed a technique in which a cleaning liquid having a temperature lower than a predetermined temperature of a processing liquid is rapidly sprayed after the processing liquid is discharged from a container (see Patent Document 4).

JP 2013-160796 A JP 2012-93658 A JP 2005-171062A JP 2006-113613 A

  The use of the above-mentioned prior art has improved the scale adhesion, and the techniques disclosed in Patent Document 1 and Patent Document 2 have made it possible to suppress, in particular, the scale adhesion of a container that performs a polymerization reaction. Further, with the techniques disclosed in Patent Document 3 and Patent Document 4, the cleaning property of the attached scale has been improved. On the other hand, it has been found that in certain cases, such as when the toner particle dispersion liquid containing the toner particles in the aqueous medium is discharged from the container at a high temperature, the effect may not be sufficiently exhibited.

  The wet manufacturing method often includes a step of discharging the toner particle dispersion from the reaction container or the storage container to the outside of the container. At this time, when the toner particle dispersion is at a high temperature, the toner particle dispersion is generally cooled in a container and then discharged out of the container. On the other hand, in recent years, the number of cases in which a toner particle dispersion is desired to be discharged at a high temperature has increased, and various techniques have been disclosed. For example, a technology in which a processing solution heated in a container is discharged at a high temperature in order to reduce an environmental load, and the processing solution is cooled by a heat exchanger and used as a heat source for heating a slurry before heating the next batch. Are disclosed.

  Further, in a method of manufacturing a toner containing a crystalline resin, a technique of discharging a treatment liquid from a container at a high temperature and rapidly cooling the same with a heat exchanger provided outside the container has been disclosed as a means for controlling crystallinity. I have. As described above, in the case where the toner particle dispersion is discharged from the container at a high temperature, it has been found that even if the prior art is used, the suppression of scale adhesion and the cleaning effect are not sufficiently exhibited. In particular, when the toner particle dispersion is discharged while being heated in a container equipped with a temperature control device, scale adhesion near the temperature control device is remarkable, and the heat transfer performance is a serious problem.

  An object of the present invention is to heat a toner particle dispersion containing toner particles in an aqueous medium inside a container provided with a temperature control jacket, and to discharge the toner particle outside the container at a high temperature even when the temperature control jacket is discharged. It is to reduce the scale adhesion to the vicinity. As a result, it is possible to suppress a decrease in the heat transfer performance of the temperature control jacket, and to obtain toner particles having stable thermal characteristics over a long period of time. It is still another object of the present invention to provide a toner manufacturing method capable of obtaining toner particles in a high yield and ensuring a high process operation rate.

In order to solve the above problems, the method for producing toner particles of the present invention,
Inside a container equipped with a temperature control jacket, a heating step of heating a toner particle dispersion containing toner particles in an aqueous medium ,
A discharging step of discharging the toner particle dispersion having passed through the heating step to the outside of the container ;
A method for producing a toner , comprising:
Assuming that the temperature of the toner particle dispersion at the time of completion of the heating step is T0 [° C.], in the heating step, the temperature of the temperature control jacket is set higher than T0 [° C.]
After the heating step is completed and before the discharging step is started, the temperature control jacket is cooled,
The temperature of the toner particle dispersion at the start of the discharging step is T1 [° C.], the extrapolated glass transition end temperature of the toner particles is Teg [° C.], and the inner wall of the container at a portion covered with the temperature control jacket. When the temperature is Tw [° C.], discharging of the toner particle dispersion is started in the discharging step under a condition satisfying a relationship of the following formula (1).
T1 ≧ Teg ≧ Tw (1)

  According to the present invention, a toner particle dispersion containing toner particles in an aqueous medium is heated inside a container equipped with a temperature control jacket, and even when the temperature is discharged outside the container at a high temperature, the temperature control is performed. Scale adhesion to the vicinity of the jacket can be reduced. As a result, a decrease in the heat transfer performance of the temperature control jacket can be suppressed, and toner particles having stable thermal characteristics over a long period of time can be obtained. Further, it is possible to obtain a toner particle in a high yield, and to provide a toner manufacturing method for securing a high process operation rate.

FIG. 1 is a schematic sectional view showing an example of a container that can be used in the present invention. It is a figure showing an example of transition of Teg, T0, T1, T2, and Tw in an example.

Hereinafter, embodiments for carrying out the present invention will be described, but the present invention is not limited thereto.
The toner production method according to the present invention includes :
Inside a container equipped with a temperature control jacket, a heating step of heating a toner particle dispersion containing toner particles in an aqueous medium ,
Discharging the toner particle dispersion having passed through the heating step to the outside of the container.

  Such a production method is mainly used in a wet production method, and specific examples include a suspension polymerization method, an emulsion polymerization method, a solution suspension method, and a dispersion polymerization method. In these manufacturing processes, it is common to store and process a processing liquid containing toner particles in a container, or to produce a toner particle by reacting in a container. After storage or reaction in a container for a required period of time, the toner particle dispersion is discharged out of the container and used. As described above, in these containers, it has been found that there is a case where the effect of suppressing the adhesion of scale is not sufficiently exhibited even when the prior art is used. In order to solve this problem, the present inventor studied when this phenomenon occurs, its mechanism and countermeasures.

  As a result, it has been found that, when the toner particle dispersion is discharged from the inside of the container at a high temperature, the effect of suppressing the scale adhesion is not sufficiently exhibited even when the prior art is used. In particular, the method includes a step of discharging the toner particle dispersion liquid after heating inside the container, and this phenomenon occurs when the temperature of the toner particle dispersion liquid at the start of discharge is equal to or higher than the extrapolated glass transition end temperature. Also, it was found that the scale adhered to the vicinity of the temperature control jacket was remarkable.

  The reason for this is that, when the toner particle dispersion is discharged from the container, it is inevitable that the liquid, bubbles, and the like remain in the container, and the container inner wall temperature remains wet at the extrapolated glass transition end temperature or higher. In this case, the toner particles were considered to be softened and easily fused. In particular, when the toner particle dispersion is heated in a container equipped with a temperature control jacket, the temperature of the temperature controller is generally set higher than the target product temperature in consideration of heat radiation. That is, since the inner wall temperature of the container near the temperature control jacket was the highest among the containers, it was considered that scale adhesion to this portion was remarkable.

Based on the above, the present inventors have studied countermeasures. As a result, before the toner particle dispersion is discharged, the temperature control jacket is cooled, and the inner wall temperature (Tw) of the portion covered with the temperature control jacket is lower than the extrapolated glass transition end temperature (Teg) of the toner particles. It was found that it was difficult to adhere to the scale by performing the discharge.
According to the study by the present inventors, it was not necessary to cool the inner wall temperature to the extrapolated glass transition start temperature. This is presumed to be because the rigidity of the toner particles can be recovered to some extent if the temperature is below the extrapolated glass transition end temperature. This makes it possible to achieve both the object of maintaining the temperature of the toner particle dispersion at a high temperature and the object of suppressing the adhesion of scale near the temperature control jacket.

<Extrapolated glass transition end temperature>
The extrapolated glass transition end temperature was measured using DSC (differential scanning calorimetry) in accordance with JIS K 7121 (the international standard is ASTM D3418-82). As the DSC used in the present embodiment, for example, “Q1000” (manufactured by TA Instruments) can be used, and the temperature correction of the device detection unit uses the melting points of indium and zinc, and the heat quantity correction uses the heat of fusion of indium. Was.

  In the measurement of the toner particles, first, about 10 mg of the toner particles were precisely weighed, placed in an aluminum pan, and an empty aluminum pan was used as a reference. In the first temperature raising process, the measurement was performed while the temperature of the measurement sample was raised from 20 ° C. to 200 ° C. at a rate of 10 ° C./min. Then, the measurement was performed while performing a cooling process of holding at 200 ° C. for 10 minutes and then cooling from 200 ° C. to 20 ° C. at 10 ° C./min.

  Furthermore, after holding at 20 ° C. for 10 minutes, the measurement was performed while the temperature was raised again from 20 ° C. to 200 ° C. at 10 ° C./min in the second temperature raising process. Based on the DSC curve obtained under these measurement conditions, a straight line obtained by extending the base line on the high-temperature side to the low-temperature side and a tangent drawn at a point where the slope of the curve of the step change portion of the glass transition becomes maximum. The temperature at the intersection is the extrapolated glass transition end temperature. The extrapolated glass transition end temperature in the present invention is a value in the second temperature raising process. This is because the extrapolated glass transition temperature in the first heating process varies depending on the heat history received by the measurement object, and thus the heat history is made uniform by performing the first heating process and the cooling process.

FIG. 1 shows an example of a container that can be used in the present invention, and the present invention will be specifically described. However, the present invention is not limited to this.
The container 1 in FIG. 1 is an example of a container for storing or reacting the toner particle dispersion, and the material is not particularly limited as long as it is a container that does not leak to the outside unintentionally. A resin container is used. If necessary, the contact surface with the processing liquid may be lined with glass or PTFE (polytetrafluoroethylene). The container 1 includes a temperature control jacket 9 and an infrared radiation thermometer 11.

  Known temperature control means include a temperature control jacket, a temperature control coil, and electromagnetic induction heating. However, in the present invention, it is necessary to use a temperature control jacket. This is because the temperature control jacket can take the widest flow path of the heat medium. That is, since a large amount of the heat medium can be flown, the temperature of the temperature controller can be quickly controlled, and it becomes possible to cool the inner wall of the container in the portion covered by the jacket but not to cool the toner particle dispersion. is there. It is particularly preferable to use a vacuum steam heating / vaporizing / cooling system as a means for controlling the jacket internal temperature, since quicker temperature control can be performed. Known means can be used for measuring the inner wall temperature of the container, and a thermocouple or a resistance temperature detector can be attached, or a radiation thermometer can be used.

  The means for discharging the toner particle dispersion from the container can be arbitrarily selected. FIG. 1 shows an example in which the discharge valve 4 is provided at the lower part of the container to discharge by its own weight, but other means such as pumping may be used. The longer the time required for discharging, and the longer the time from completion of discharging to cleaning of the inside of the container, the more easily scale adhesion occurs. Depending on the amount of the toner particle dispersion, the discharging means, and the temperature of the toner particle dispersion, if the discharge takes more than 3 minutes, the scale adhesion becomes remarkable. However, by employing the constitution of the present invention, the reduction can be achieved.

  When the toner particle dispersion liquid 2 is discharged from the container 1, the liquid level 3 is lowered, but it is inevitable that the toner particle dispersion liquid remains on the container inner members such as the container inner wall 5 and the stirring blade 6. Conventionally, the toner particle dispersion is generally discharged after being cooled, so that the residue remaining after the toner particle dispersion or the like does not immediately fuse to form scale adhesion. Therefore, the subject of the present invention has not occurred even if the next batch of toner particle dispersion is received after the discharge is completed, or the inside of the container is cleaned after the discharge is completed.

  On the other hand, as described above, in recent years, cases in which the toner particle dispersion is desired to be discharged at a high temperature have been increasing. In such a case, if the toner particle dispersion liquid has a residual residue, the softened toner particles are likely to be fused into the container. Even in the container, especially near the temperature controller such as a temperature control jacket, the temperature is highest and this problem is remarkable. In the present invention, the temperature of the container inner wall of the portion covered with the temperature control jacket is set to be equal to or lower than the extrapolated glass transition end temperature of the toner particles, so that the temperature of the toner particle dispersion is higher than that of the toner particle dispersion liquid. It was discovered that the fusion of steel could be suppressed, and the problem was solved.

FIG. 2 is a diagram illustrating an example of transition of Teg, T0, T1, T2, and Tw in the embodiment. The dotted line indicates the temperature of the dispersion, and the solid line indicates the temperature of the inner wall.
T0 [° C.] indicates the temperature of the toner particle dispersion when the heating step is completed,
T1 [° C.] indicates the temperature of the toner particle dispersion at the start of the discharging step,
T2 [° C.] indicates the temperature of the toner particle dispersion at the time when the discharging step is completed,
Teg [° C.] indicates an extrapolated glass transition end temperature of the toner particles,
Tw [° C.] indicates the inner wall temperature of the portion of the container covered with the temperature control jacket.

In the discharging step of the present invention, discharging of the toner particle dispersion liquid is started under a condition satisfying the relationship of the following expression (1).
T1 ≧ Teg ≧ Tw (1)
By satisfying such conditions, the adhesion of scale can be reduced.

Further, it is preferable to discharge the toner particle dispersion under the conditions satisfying the following expressions (2), (3), and (4).
T0−T1 ≦ 5.0 (2)
T0−T2 ≦ 10.0 (3)
T2 ≧ Teg (4)

  By satisfying such conditions, as described above, not only the effect of reducing the energy and tact time required for reheating the toner particle dispersion liquid in the next step, but also in a container which is likely to occur when the configuration of the present invention is adopted. It is possible to suppress temperature unevenness of the toner particle dispersion liquid.

  That is, when the container inner wall temperature (Tw) is equal to or lower than the extrapolated glass transition end temperature (Teg), and when the toner particle dispersion liquid temperature (T1) is higher than that, the liquid temperature becomes lower as the portion is closer to the inner wall. Temperature unevenness such as a higher liquid temperature is likely to occur. When the temperature non-uniformity occurs, the toner particles discharged while the temperature is high and the toner particles discharged while the temperature is low exist, and the quality of the toner may also be non-uniform. In particular, in the case of a toner manufacturing method in which the crystallinity is controlled immediately after discharge, since the crystallinity varies depending on the heat history of the toner particles, it is important to suppress the occurrence of temperature unevenness.

According to the study of the present inventors, when T0-T1 is equal to or lower than 5.0 ° C., when the toner particle dispersion is cooled and discharged, the dispersion near the inner wall of the container is cooled. It is difficult for temperature unevenness to occur.
Further, when T0-T2 was 10.0 ° C. or less, the temperature of the toner particles in the early stage of discharge and the temperature of the toner particles in the latter half of discharge were not easily generated.
Further, when T2 is equal to or higher than the extrapolated glass transition end temperature (Teg), it becomes easy to control the thermal history of the toner in the subsequent steps. In particular, in order to control the crystallinity, the crystallization temperature of the material is important, but since the crystallization temperature is generally higher than the extrapolated glass transition end temperature, the material is discharged at a high temperature and crystallized from the resin. When controlling the properties, it is important to satisfy T2 ≧ Teg.

  In the case where the container inner wall temperature (Tw) of the portion covered with the temperature control jacket is cooled below the extrapolated glass transition end temperature (Teg) of the toner resin, and then the discharge is started, the temperature of the toner particle dispersion drops. obtain. To prevent this, it is not necessary to continue jacket cooling after the discharge has started. For example, by keeping the temperature around the extrapolated glass transition end temperature (Teg) of the resin for toner, the temperature of the inner wall of the container (Tw) is kept below the extrapolated glass transition end temperature (Teg), and the temperature of the dispersion liquid sharply increases. Can also be suppressed.

  In addition, pressurizing the inside of the container at the time of discharge, increasing the discharge speed by installing a pump in the discharge line, etc., by means of discharging quickly before the temperature of the dispersion liquid decreases, by adding a heated dispersion medium, etc. Means for preventing a decrease in the liquid temperature of the dispersion may be used. In order to discharge the processing liquid at a high temperature, the above means can be used to suppress a decrease in the processing liquid temperature. In this way, even when the toner particle dispersion is heated in the next step, the time and energy required for raising the temperature can be reduced. Further, even when the crystallinity is controlled, it is possible to discharge the toner particles at a temperature equal to or higher than the extrapolated glass transition end temperature.

Further, in the discharging step, it is particularly preferable to discharge the toner particle dispersion liquid while spraying the cleaning liquid inside the container.
By discharging the cleaning liquid while spraying, the cleaning liquid can be brought into contact with the liquid surface at the same time as the liquid level is lowered and the remaining wet surface is exposed. By contacting the cleaning liquid at the same time that the remaining wet surface is exposed, the liquid medium can be washed before the liquid medium evaporates from the remaining wet and the viscosity increases, so that the scale adhesion can be reduced. As a means, for example, the cleaning liquid spraying nozzle 7 connected to the cleaning liquid supply line can be installed in the container, and the cleaning liquid can be sprayed into the container.

  The discharge speed of the processing liquid at the time of discharge may be arbitrarily controlled as needed. Can be slow or fast. When the discharge speed is low, the rate of decrease in the liquid level is low, so that the remaining of the processing liquid can be reduced. Conversely, when the discharge speed is increased, the remaining wet increases, but by adopting the configuration of the present invention, the fusion of the remaining wet can be reduced.

  Examples of the container inner member include a stirring blade 6, a baffle (baffle) for uniform mixing, a thermometer for temperature control, and a heating / cooling source. In the present invention, any stirring blade can be used as the stirring blade, and examples thereof include a paddle blade, a propeller blade, a full zone blade, an anchor blade, a turbine blade, and a max blend blade.

  When the container is provided with a stirrer, it is preferable to start discharge while stirring the treatment liquid. Even when the treatment liquid contains bubbles or has a thixotropic property, the thickness of the remaining wet can be reduced by discharging while stirring. However, if the processing liquid is discharged by its own weight from the discharge valve provided at the bottom of the container, the discharge speed may be slower due to the relationship between the centrifugal force due to stirring and the weight, so adjust the stirring speed as necessary. Do.

  Here, as a representative example, a detailed embodiment for carrying out the present invention will be described using an example of obtaining a toner particle dispersion by a suspension polymerization method.

<Dissolution process>
First, as a dissolution step, a polymerizable monomer, a toner resin such as a release agent, a colorant, a charge control agent, a cross-linking agent, other liquid media and additives are added to a dissolution container, and an optional stirrer or A polymerizable monomer composition uniformly dissolved or dispersed by a disperser or the like is prepared. At this time, the polymerizable monomer composition may be heated in order to promote dissolution of the resin for the toner and uniform mixing. As a means for heating, a known method can be selected, and examples thereof include a method of attaching a jacket for temperature adjustment, a coil for temperature adjustment, and a method of attaching electromagnetic induction heating to a melting vessel.

  The temperature for heating in the dissolving step can be selected according to the solid-liquid ratio or the melting point of the release agent. The prepared polymerizable monomer composition is discharged from the container and sent to the next granulation step. At this time, if the polymerizable monomer composition which is the processing liquid is heated, if the temperature is lowered, the dissolution and dispersion state may become non-uniform due to precipitation of the resin for toner and the like. Is preferably discharged without lowering the temperature.

<Granulation process>
The polymerizable monomer composition sent to the granulation step is mixed with an aqueous phase containing a dispersant prepared in a granulation container in advance, and an optional stirrer having a high shear force. The droplets composed of the polymerizable monomer composition are granulated to a desired size of the toner particles by using a disperser. In the suspension polymerization method, it is usually preferable to use 100 to 3000% by weight of water as a dispersion medium with respect to 100% by weight of the polymerizable monomer composition.

  The granulation step is preferably performed in a heated state in order to prevent the precipitation of the resin for the toner, and the temperature is preferably from 40 ° C. to 100 ° C. depending on the solid-liquid ratio and the melting point of the release agent. If necessary, the granulation step can be performed in a pressurized state in the granulation container. The treatment liquid after the granulation is discharged from the container and sent to the next polymerization step.

<Polymerization step>
In the polymerization step, the treatment liquid is heated in a polymerization vessel to carry out a polymerization reaction to obtain a toner particle dispersion. The polymerization is carried out at a polymerization temperature of 40 ° C or higher, generally 50 to 95 ° C. In order to improve the low-temperature fixability of the toner particles, a polymer having a low molecular weight can be obtained by pressurizing the inside of the polymerization container and heating it to a temperature equal to or higher than the standard boiling point of water. When the polymerization initiator is added, it can be carried out at any time and for any required time after the preparation of the polymerizable monomer composition. The temperature may be raised in the latter half of the polymerization reaction in order to obtain a desired molecular weight distribution. In the polymerization step, since the temperature of the processing liquid has a great influence on the fixing performance of the toner particles, the stirring operation is generally performed so that the temperature distribution in the container becomes uniform.

  In the polymerization step, it is particularly necessary to pay attention to scale adhesion to the temperature controller. If the scale adheres to the temperature controller, heat transfer into the container is hindered, so that it becomes difficult to control the temperature of the processing solution. Therefore, it is difficult to obtain toner particles having stable fixing performance over a long period of time. After the polymerization reaction is advanced to a target polymerization rate to obtain a toner particle dispersion, the dispersion is discharged from the polymerization container and sent to the next step.

  In the next step, when an unreacted polymerizable monomer, by-product or the like is removed from the system, a distillation operation is performed. Since the distillation operation is performed at a high temperature near the standard boiling point of water, it is preferable not to lower the temperature of the toner particle dispersion discharged from the polymerization vessel. It is also preferable to discharge the toner particle dispersion at a high temperature when reusing the heat of the treatment liquid or when controlling the crystallinity of the generated polymer or crystalline material. For these purposes, when the toner particle dispersion is discharged while maintaining the extrapolated glass transition end temperature of the toner particles or higher, fusion of the toner particles is likely to occur near the temperature control jacket. Fusion can be reduced.

  For example, the cooling of the temperature control jacket is started before the discharge of the processing liquid is started, and the discharge is immediately performed when the inner wall temperature of the container covered by the temperature control jacket reaches the temperature at which the extraneous glass transition of the toner particles ends. To start. In order to suppress the cooling of the toner particle dispersion after the discharge is started, it is preferable to control the temperature of the temperature adjustment jacket at a temperature as high as possible within a range in which the inner wall temperature of the container does not become higher than the extrapolated glass transition end temperature. It is particularly preferable to spray the heated cleaning liquid into the container while discharging. Accordingly, it is possible to suppress cooling of the toner particle dispersion, and at the same time, it is possible to wash the remaining toner particle dispersion, so that the scale adhesion can be further suppressed.

As the polymerizable monomer used for the toner particles of the suspension polymerization method, a vinyl polymerizable monomer capable of radical polymerization is preferably used. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.
For example, styrene derivatives such as styrene and 2,4-dimethylstyrene, and acrylic polymerizable monomers such as n-butyl acrylate are preferably used. Other examples include methacrylic polymerizable monomers such as methyl methacrylate, and vinyl esters such as vinyl acetate. Among these, the present invention is a method for producing toner particles using styrene alone or in combination of two or more kinds of styrene and other polymerizable monomers. Can be used.

  As the colorant used for the toner particles of the suspension polymerization method, a known colorant can be used. For example, C.I. I. Direct Red 1, C.I. I. Direct Blue 1, C.I. I. Dyes such as Basic Green 6; and pigments such as carbon black, mineral fast yellow, cadmium red, brilliant carmine 3B, and phthalocyanine blue.

  As the release agent used for the toner particles of the suspension polymerization method, wax in a solid state at room temperature is preferable in terms of blocking resistance, durability of a large number of sheets, low-temperature fixing property, and offset resistance of the toner. For example, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, ester wax and the like can be mentioned. In order to improve the translucency of the image fixed on the OHP, a linear ester wax is particularly preferably used.

  The charge control agent used in the toner of the suspension polymerization method can be externally added to the toner particles, but is added to the inside of the toner particles by dispersion in the polymerizable monomer composition or the like. It is also possible. Examples of the charge control agent having a negative charge include organic metal compounds and chelate compounds, and examples of the charge control agent having a positive charge include nigrosine and amine compounds.

  Examples of the polymerization initiator used for the toner particles of the suspension polymerization method include potassium peroxodisulfate, aqueous hydrogen peroxide, 2,2′-azobis- (2,4-dimethylvaleronitrile), benzoyl peroxide, and t-butyl peroxide. Oxylaurate and the like.

  Examples of the crosslinking agent include polyfunctional compounds such as divinylbenzene, 4,4'-divinylbiphenyl, and ethylene glycol di (meth) acrylate.

  In addition, as a dispersion stabilizer for dispersing a polymerizable monomer composition in an aqueous medium in a suspension polymerization method, a water-soluble polymer that generally exhibits repulsion due to steric hindrance, and an electrostatic repulsion are used. It is broadly classified into poorly water-soluble inorganic compounds for stabilizing dispersion. The fine particles of the poorly water-soluble inorganic compound are preferably used because they are dissolved by an acid or an alkali and can be easily removed by washing with an acid or an alkali after polymerization. Among the poorly water-soluble inorganic compounds, metal phosphates are preferably used. Among them, alkaline earth metal phosphates such as calcium phosphate are preferred. For example, in the case of tricalcium phosphate, a dispersion stabilizer suitable for a suspension polymerization method can be obtained by adding and mixing an aqueous solution of trisodium phosphate and an aqueous solution of calcium chloride with sufficient stirring.

  In the case of a polymerization method using an aqueous dispersion medium such as suspension polymerization, inclusion of a release agent can be promoted by adding a polar resin to the polymerizable monomer composition. When the polar resin is present in the polymerizable monomer composition in the aqueous medium, the polar resin migrates to the vicinity of the interface between the aqueous medium and the polymerizable monomer composition due to a difference in hydrophilicity. Polar resin is unevenly distributed. As a result, the toner particles have a capsule structure having a core / shell structure, and even when a large amount of the release agent is contained in the core portion, the encapsulation property of the release agent is improved.

  In addition, if a polar resin having a high melting temperature is selected for the polar resin used for the shell portion, even if the core resin is designed to be melted at a lower temperature for the purpose of fixing at a low temperature, adverse effects such as blocking during storage may be caused. Can be suppressed. As such a polar resin, a saturated or unsaturated polyester resin is particularly preferable since the fluidity of the polar resin itself can be expected when the shell is formed unevenly on the surface of the toner particles.

  The toner particle dispersion thus obtained is sent to a solid-liquid separation / washing step. At this time, the toner particle dispersion may be treated with an acid or an alkali for the purpose of removing the dispersion stabilizer attached to the surface of the toner particles. Thereafter, solid-liquid separation is performed by a general solid-liquid separation method. To completely remove the acid or alkali and the dispersion stabilizer dissolved therein, water is added again to wash the toner particles. This process is repeated several times, and after sufficient washing is performed, solid-liquid separation is performed again to obtain a toner cake. The obtained toner cake is dried by a known drying means, and if necessary, a particle group having a particle size outside a predetermined range is separated by classification. At this time, the separated non-predetermined particle group may be reused in order to improve the final yield.

In the toner obtained by the present invention, only the polymerized toner particles obtained by the above-described polymerization method, or other external additives may be externally added to the toner particles for the purpose of imparting various properties to the toner.
The external additive preferably has a particle size of 1/10 or less of the average particle size of the toner particles from the viewpoint of durability when added to the toner. Examples of the external additives include metal oxides such as aluminum oxide, nitrides such as silicon nitride, carbides such as silicon carbide, inorganic metal salts such as calcium sulfate, fatty acid metal salts such as zinc stearate, carbon black, silica and the like. Is used.

  The toner produced according to the present invention can be used for either developer, usually as a one-component or two-component developer. For example, in the case of a magnetic toner in which a magnetic substance is contained in toner particles as a one-component developer, there is a method of using a magnet built in a developing sleeve to transport and charge the magnetic toner. When a non-magnetic toner containing no magnetic material is used, there is a method in which a blade, a fur brush, or the like is used to forcibly frictionally charge the toner with a developing sleeve and adhere the toner onto the sleeve to convey the toner.

  On the other hand, when used as a two-component developer, a carrier is used as a developer together with the toner of the present invention. The carrier is mainly composed of a single ferrite and a composite ferrite mainly composed of iron, copper, zinc, nickel, cobalt, manganese and chromium. Generally, a method is used in which the inorganic oxide is calcined and granulated to generate carrier core particles in advance and then coat a resin. Further, from the viewpoint of reducing the load on the toner of the carrier, a method of obtaining a low-density dispersed carrier by kneading the inorganic oxide and the resin and then pulverizing and classifying the mixture, or suspending the mixture of the inorganic oxide and the monomer in an aqueous medium. It is also possible to use a method of obtaining a polymerization carrier by turbid polymerization.

  Hereinafter, the present invention will be described in more detail based on examples, but embodiments of the present invention are not limited thereto. First, the measurement method used in the present invention will be described below.

(1) Measurement of Extrapolated Glass Transition End Temperature of Toner Particles First, it is necessary to determine the extrapolated glass transition end temperature of toner particles. The measurement sample is obtained by collecting a toner particle dispersion, adjusting the pH to 1.5 or less with hydrochloric acid, and then performing suction filtration to perform solid-liquid separation. Further, the wet cake formed by suction filtration is washed with ion-exchanged water. Sprinkle washing is performed until bubbles of washing water that have passed through the wet cake disappear. The washed wet cake was crushed and dried with a vacuum dryer at 40 ° C. to obtain a measurement sample.

  The measurement of the extrapolated glass transition end temperature used DSC "Q1000" (manufactured by TA Instruments). The temperature of the detector was corrected using the melting points of indium and zinc, and the amount of heat was corrected using the heat of fusion of indium. In the measurement of the toner particles, first, about 10 mg of the toner particles were precisely weighed, placed in an aluminum pan, and an empty aluminum pan was used as a reference. In the first temperature raising process, the measurement was performed while the temperature of the measurement sample was raised from 20 ° C. to 200 ° C. at a rate of 10 ° C./min. Then, the measurement was performed while performing a cooling process of holding at 200 ° C. for 10 minutes and then cooling from 200 ° C. to 20 ° C. at 10 ° C./min.

  Furthermore, after holding at 20 ° C. for 10 minutes, the measurement was performed while the temperature was raised again from 20 ° C. to 200 ° C. at 10 ° C./min in the second temperature raising process. Based on the DSC curve of the second heating process obtained under these measurement conditions, a point where the slope of the straight line obtained by extending the high-temperature-side base line to the low-temperature side and the curve of the step change portion of the glass transition becomes maximum. The temperature at the point of intersection with the tangent drawn in step is defined as the extrapolated glass transition end temperature.

(2) Evaluation of Yield / Measurement of Scale Attached Material In order to evaluate the effect of improving the yield, the amount of scale attached is quantified. Scale adhesion is essentially a product, and the smaller the scale adhesion, the better the yield. A test piece is placed in a container to measure the amount of scale deposit. The test piece used is an aluminum plate, 100 mm long × 50 mm wide × 2 mm thick. As shown at 10 in FIG. 1, four test pieces are placed on the upper and lower surfaces of the liquid at opposing positions on the inner wall of the container. After one batch of toner particles are produced, the test pieces are removed from the container, immersed in water and lightly washed with water. And weighed. The difference between the weight of the test piece before the production of the toner particles and the weight of the four test pieces is taken as the amount of scale deposit.

A: Very good level (scale deposit amount is less than 2.0 g)
B: Good level (scale attachment amount is 2.0 g or more and less than 4.0 g)
C: Permissible level (the amount of scale deposits is 4.0 g or more and less than 8.0 g)
D: bad level (scale deposit amount is 8.0 g or more)

(3) Evaluation of Stability of Thermal Characteristics of Toner Particles In the polymerization step, the thermal characteristics of the toner particles are stabilized for a long period of time by suppressing the adhesion of scale to the temperature controller. As an index of the thermal characteristics of the toner particles, a melt index value at a temperature of 110 ° C. and a load of 10 kg is used. The melt index value indicates the easiness of melting of the toner particles at an arbitrary temperature and load, and can be used as an index of thermal characteristics when fixing the toner at an arbitrary temperature and load. Here, the method for measuring the melt index of the toner particles will be described below.

<Measurement of melt index>
The melt index indicates a discharge amount from an orifice at an arbitrary temperature and a load for 10 minutes. In this embodiment, the values are measured under the following conditions. This basically conforms to <JIS K-7210>.
A Semi-automatic 2-A Mel Index (Toyo Seiki Co. Ltd.) is used as a measuring device.
An orifice having a cavity inner diameter of 2.095 mm is put therein, the temperature is previously adjusted to 110 ° C., and 3 to 8 g of a toner particle sample is weighed and put therein. At this time, the metal piston is set while paying attention to prevent air bubbles from entering, and the temperature is maintained for 5 minutes or more. Thereafter, the measurement is performed while applying a constant load such that the total of the piston and the weight becomes 10 kg. The measurement may be performed at an arbitrary time, and may be converted into a discharge amount for 10 minutes.

  The stability evaluation of the thermal characteristics of the toner particles is performed by continuously producing 10 batches of the toner particles using the same polymerization container, thereby producing the toner particles while depositing the scale deposit. The melt index value of the toner particles for 10 batches obtained as described above is measured, and evaluated by its standard deviation.

A: Very good level (standard deviation is less than 0.5)
B: Good level (standard deviation is 0.5 or more and less than 1.0)
C: allowable level (standard deviation is 1.0 or more and less than 2.0)
D: Bad level (standard deviation is 2.0 or more)

(4) Evaluation of Low-Temperature Fixability In this example, the obtained toner particle dispersion is rapidly cooled to suppress the crystal growth of paraffin wax in the toner particles, thereby improving the low-temperature fixability. Therefore, when the crystallinity of the paraffin wax is not controlled uniformly due to, for example, the occurrence of temperature unevenness during discharge, the lower limit temperature at which fixing can be performed increases. 2.5 parts by mass of dry silica (BET specific surface area: 120 m ^{2 /} g) having a primary particle size of 12 nm treated with silicone oil and hexamethylsilazane is externally added to 100 parts by mass of the toner particles obtained in the production of the first batch. Thus, a toner was obtained.

A two-component developer was prepared by mixing the toner and a ferrite carrier (average particle size: 42 μm) surface-coated with a silicone resin so that the toner concentration became 6% by mass. An unfixed toner image (0.6 mg / cm ² ) was formed on an image receiving paper (80 g / m ² ) using a commercially available full-color digital copying machine (CLC700, manufactured by Canon Inc.). A fixing unit removed from a commercially available full-color digital copying machine (CLC700, manufactured by Canon Inc.) was modified so that the fixing temperature could be adjusted, and a fixing test of an unfixed image was performed using the fixing unit. At normal temperature and normal humidity, the process speed was set to 200 mm / sec, and the toner image was fixed at each temperature while changing the set temperature in the range of 130 ° C. to 230 ° C. every 5 ° C.

The obtained fixed image was rubbed five times with a silbon paper under a load of 4.9 kPa, and the temperature at which the density reduction rate before and after the rubbing was 10% or less was defined as the fixing start temperature on the low temperature side. The lower the temperature, the better the low-temperature fixability.
The image density was measured using a “Macbeth reflection densitometer RD918” (manufactured by Macbeth) to measure the reflection density of a printout image of a white background portion where the original density was 0.00.

[Example 1]
<Dissolution process>
The following materials were heated to 60 ° C. in a dissolving vessel and dissolved and mixed for 30 minutes to prepare a polymerizable monomer composition.
70 parts by mass of styrene monomer 30 parts by mass of n-butyl acrylate Saturated polyester resin (polycondensate of propylene oxide-modified bisphenol A (2 mol adduct) and terephthalic acid (polymerization molar ratio 10:12), Tg = 68 C, Mw = 10000, Mw / Mn = 5.12) 8 parts by mass Tg: glass transition temperature, Mw: weight average molecular weight, Mn: number average molecular weight, paraffin wax HNP-5 (Nippon Seiro Co., Ltd.) 8 Parts by mass: carbon black (BET specific surface area = 80 m ² / g, oil absorption = 120 mL / 100 g)
8 parts by mass, 1 part by mass of salicylic acid compound E-88 (manufactured by Orient Chemical Industry Co., Ltd.), 0.1 part by mass of zinc phthalocyanine The following materials were mixed with a solution obtained by dissolving and mixing for 30 minutes.
8 parts by mass of polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) The polymerizable monomer composition subjected to dissolution and mixing is kept at 60 ° C. without lowering the temperature in order to prevent precipitation of WAX. It was discharged from the dissolution vessel and transferred to the granulation step.

<Granulation process>
After charging 5 parts by mass of Na ₃ PO ₄ .12H ₂ O to 332 parts by mass of ion-exchanged water and heating to 60 ° C., 58.3 revolutions per second (3500 rpm) using CLEARMIX (manufactured by M Technique Co., Ltd.) ). To this, 27 parts by mass of a 1.0 mol / liter CaCl ₂ aqueous solution was added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .
The polymerizable monomer composition was charged into the aqueous medium, and the mixture was stirred at 4500 rpm for 15 minutes in a clear mix at a temperature of 60 ° C. under an N ₂ atmosphere to granulate the polymerizable monomer composition. At the time of discharge, the transfer to the reaction step was started, and at the same time, 60 ° C. hot water was sprayed as a washing liquid into the granulation container.

<Polymerization step>
The granulated treatment liquid was transferred to a polymerization vessel equipped with a temperature control jacket as shown in FIG. 1 and using a vacuum steam heating, vaporizing and cooling system as a temperature control system. An infrared radiation thermometer IR-CDB (manufactured by Chino Corporation) was installed on the sight glass of the polymerization container to measure the inner wall temperature of the container. In addition, four spiral jet hollow cone sprays B1 / 4BSJ-SS18013 (manufactured by Spraying Systems Japan KK) were installed as spray nozzles for the washing liquid in the container.

  After receiving all the processing liquids from the granulation process, the mixture is heated to 65 ° C. while stirring with a full zone stirring blade (manufactured by Shinko Environmental Solutions Co., Ltd.), and the polymerization reaction is performed for 10 hours. And heated for 1 hour to adjust the molecular weight distribution to obtain a toner particle dispersion. Here, the toner particle dispersion was sampled and measured according to the above-described method of measuring the extrapolated glass transition end temperature of the toner particles. Teg = 60.0 ° C.

  Here, the desired polymerization reaction has been completed, and the heating step in the polymerization vessel has been completed. The temperature T0 of the toner particle dispersion at the end of the heating step was 85.0 ° C., the temperature inside the jacket was 94.0 ° C., and the temperature inside the container at the portion covered with the jacket was 93.0 ° C. After the completion of the heating step, cooling in the jacket for temperature control was started. Eight minutes after the start of cooling, the inside temperature of the jacket reached 50.0 ° C., and the inner wall temperature of the portion covered with the jacket reached Tw = 55.0 ° C. . When the temperature reached Tw = 55.0 ° C., the cooling of the temperature control jacket was stopped, but control was performed so that Tw was kept at 55.0 ° C. or less until the discharge was completed.

  When the temperature reached Tw = 55.0 ° C., the discharge valve of the polymerization vessel was opened to start discharging the processing solution, and the solution was transferred to the next step. At this time, the toner particle dispersion temperature T1 was 83.0 ° C. Simultaneously with the start of the discharge of the toner particle dispersion, the spraying of 85 ° C. warm water into the polymerization vessel as a cleaning liquid was started. The supply pressure of the cleaning hot water was 0.3 MPa and the supply rate was 10 kg / min, and it was confirmed that the cleaning liquid was evenly in contact with the inner wall of the container and the inner member of the container. The discharge speed of the treatment liquid was 400 kg / min, and the discharge step required 20.5 minutes. The temperature of the hot water and the temperature control jacket was adjusted so that the temperature T2 of the toner particle dispersion at the end of the discharge was 81.0 ° C. Table 1 shows the evaluation results of the yield in the polymerization step. A plate type heat exchanger was installed in the transfer line to the washing step, and the toner particles were rapidly cooled to a temperature below the extrapolated glass transition end temperature and transferred while suppressing crystallization of paraffin wax.

<Washing / solid-liquid separation / drying process>
Hydrochloric acid was added to the obtained toner particle dispersion and stirred to dissolve Ca ₃ (PO ₄ ) ₂ covering the toner particles, followed by solid-liquid separation with a pressure filter to obtain a toner cake. This was poured into water, stirred, and again made into a dispersion, and then subjected to solid-liquid separation with the above-mentioned filter. Re-dispersion of the toner cake in water and solid-liquid separation were repeated until Ca ₃ (PO ₄ ) ₂ was sufficiently removed, and finally solid-liquid separation was performed to obtain a toner cake.

The obtained toner cake was dried while being crushed with a flash dryer (manufactured by Seishin Enterprise Co., Ltd .: flash jet dryer: pipe diameter 0.1016 m) to obtain toner particles. Drying conditions were as follows: blowing temperature of 90 ° C., blowing air volume of 10 m ³ / min, dryer outlet temperature of 40 ° C., and supply speed of the toner cake were adjusted so that the outlet temperature did not deviate from 40 ° C. according to the water content of the toner cake.

<Evaluation>
The above steps were repeated for 10 batches, and the obtained toner particles were evaluated according to the above-described method for evaluating the stability of thermal characteristics of toner particles. The low-temperature fixability of the toner particles of the first batch was evaluated. Table 1 shows the results.

[Example 2]
Control was performed so that Tw = 59.0 ° C., T1 = 84.0 ° C., and T2 = 82.0 ° C. at the start of discharge in the polymerization step. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

[Example 3]
Control was performed such that Tw = 10.0 ° C., T1 = 61.0 ° C., and T2 = 59.0 ° C. at the start of discharge in the polymerization step. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

[Example 4]
Control was performed such that Tw = 50.0 ° C., T1 = 81.0 ° C., and T2 = 76.0 ° C. at the start of discharge in the polymerization step. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

[Example 5]
Control was performed so that Tw = 55.0 ° C., T1 = 83.0 ° C., and T2 = 59.0 ° C. at the start of discharge in the polymerization step. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

[Example 6]
Control was performed so that Tw = 45.0 ° C., T1 = 79.0 ° C., and T2 = 74.0 ° C. at the start of discharge in the polymerization step. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

[Example 7]
Control was performed so that Tw = 55.0 ° C., T1 = 83.0 ° C., and T2 = 74.0 ° C. at the start of discharge in the polymerization step. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

Example 8
Control was performed so that Tw = 45.0 ° C., T1 = 79.0 ° C., and T2 = 76.0 ° C. at the start of discharge in the polymerization step. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

[Example 9]
Control was performed so that Tw = 45.0 ° C., T1 = 79.0 ° C., and T2 = 59.0 ° C. at the start of discharge in the polymerization step. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

[Example 10]
After the completion of the polymerization reaction in the polymerization step, the toner particle dispersion was maintained at 65.0 ° C. and maintained for 30 minutes to complete the heating step. The temperature T0 of the toner particle dispersion at the end of the heating step was 65.0 ° C., the temperature inside the jacket was 73.0 ° C., and the temperature inside the container at the portion covered with the jacket was 70.0 ° C. After the heating step, the inside of the temperature control jacket starts to be cooled, and when the inner wall temperature of the container reaches Tw = 10.0 ° C., the discharge valve of the polymerization container is opened to start discharge of the processing solution and transferred to the next step. did. Control was performed so that T1 = 63.0 ° C. and T2 = 59.0 ° C. in the discharging step. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

[Example 11]
No cleaning liquid was sprayed in the discharge step of the polymerization step. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

[Comparative Example 1]
After the completion of the heating step in the polymerization step, the temperature control jacket was discharged without cooling. At this time, Tw = 93.0 ° C., T0 = 85.0 ° C., T1 = 85.0 ° C., and T2 = 85.0 ° C. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

[Comparative Example 2]
After the heating step in the polymerization step, the temperature control jacket was cooled, and when Tw = 61.0 ° C., discharging was started. At this time, T1 = 84.0 ° C. and T2 = 82.0 ° C. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

[Reference Example 1]
After the heating step in the polymerization step, the temperature control jacket was cooled, and after cooling to T1 = 55.0 ° C., discharging was started. At this time, Tw = 10.0 ° C. and T2 = 51.0 ° C. Otherwise, toner particles were produced in the same manner as in Example 1. Table 1 shows the evaluation results.

As is clear from Table 1, Examples 1 to 11 were able to reduce the scale adhesion as compared with Comparative Examples 1 and 2. Further, the toner particles obtained in Examples 1 to 11 had stable thermal characteristics and good fixability.
Further, in Reference Example 1 in which T1 (= 55.0 ° C.) is equal to or lower than Teg (= 60.0 ° C.), crystallization could not be performed, and thus, good low-temperature fixability was not obtained.

In Example 2, in which the difference between Teg (= 60.0 ° C.) and Tw (= 59.0 ° C.) was small, the amount of scale deposits was larger than in Examples 1, 3 to 11.
In Example 3 having a low T1 (= 61.0 ° C.), the amount of scale deposits was not large as compared with Examples 1 to 11, but it took time to raise the temperature in the next step.
Examples 1, 2, 4, and 11 that satisfy all of the expressions (2) to (4) are compared with Examples 3, 5, and 10 that do not satisfy any of the expressions (2) to (4). And good low-temperature fixability.

1. Container 2. 2. toner particle dispersion Liquid level 4. Discharge valve 5. Container inner wall 6. Stirring blade
7. 7. Cleaning liquid spray nozzle Discharge line 9. Temperature control jacket 10. Test piece 11. Infrared radiation thermometer

Claims (3)

Inside a container equipped with a temperature control jacket, a heating step of heating a toner particle dispersion containing toner particles in an aqueous medium ,
A discharging step of discharging the toner particle dispersion having passed through the heating step to the outside of the container ;
A method for producing a toner , comprising:
Assuming that the temperature of the toner particle dispersion at the time of completion of the heating step is T0 [° C.], in the heating step, the temperature of the temperature control jacket is set higher than T0 [° C.]
After the heating step is completed and before the discharging step is started, the temperature control jacket is cooled,
The temperature of the toner particle dispersion at the start of the discharging step is T1 [° C.], the extrapolated glass transition end temperature of the toner particles is Teg [° C.], and the portion of the container covered with the temperature control jacket is When the inner wall temperature is Tw [° C.], the discharging process of the toner particle dispersion is started under the conditions satisfying the relationship of the following formula (1) in the discharging step.
T1 ≧ Teg ≧ Tw (1) When the temperature of the toner particle dispersion at the end of the heating step is T0 [° C.] and the temperature of the toner particle dispersion at the end of the discharge step is T2 [° C.], the following formula (2) is used. The method for producing a toner according to claim 1, wherein the toner particle dispersion is discharged under a condition satisfying (3), (3), and (4).
T0−T1 ≦ 5.0 (2)
T0−T2 ≦ 10.0 (3)
T2 ≧ Teg (4) 3. The method for producing a toner according to claim 1, wherein in the discharging step, the toner particle dispersion is discharged while spraying a cleaning liquid into the container.

Images