JP6706037B2 - Method of manufacturing toner particles - Google Patents

Description

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

As a method of manufacturing an electrostatic charge image developing toner (hereinafter may be simply referred to as “toner”), a method of reducing the environmental load at the time of manufacturing, easily obtaining a toner having a small particle size and a sharp particle size distribution, shape control, Wet manufacturing methods are often used because they are easy to encapsulate.
The wet manufacturing method is a method of manufacturing toner particles in a liquid medium. Manufacturing methods such as a suspension polymerization method, an emulsion polymerization method, a dissolution suspension method, and a dispersion polymerization method are carried out depending on the material constituting the toner particles and the desired toner particle shape.

In the wet manufacturing method, scale is likely to adhere to a container such as a storage container for a treatment liquid containing a toner resin and a liquid medium and a reaction container. Adhesion of scale causes yield loss and unintentional mixing into the next batch. In addition, the work of removing the scale occurs, leading to a decrease in the operating rate. Furthermore, when a temperature controller is provided in the container, heat transfer performance deteriorates if scale adheres to the temperature controller, the temperature rising/falling speed and temperature control become unstable, and toner particles with stable thermal characteristics can be obtained. Becomes difficult.

Therefore, in the wet manufacturing method, various techniques for suppressing scale adhesion to the inner wall of the container or various methods for cleaning the adhered scale have been proposed.
For example, as a technique for suppressing scale adhesion, a technique for performing a polymerization reaction in the presence of a substance having a vapor pressure higher than a certain level by the polymerizable monomer is disclosed (see Patent Document 1). Also disclosed is a technique 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 perform a polymerization step, and the contents of the container are discharged and then an aqueous solution having a pH of 9 or more is contacted (Patent Reference 2).

Further, as a technique for cleaning the adhered scale, a technique has been disclosed in which the treatment liquid is discharged from the manufacturing apparatus and then the deposits on the inner wall surface of the manufacturing apparatus are removed with high-pressure water (see Patent Document 3). Further, there is disclosed a technique of promptly spraying a cleaning liquid having a temperature lower than a certain temperature than the temperature of the processing liquid after discharging the processing liquid from the container (see Patent Document 4).

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

Scale adhesion has been improved by using the above-mentioned prior art, and the technology disclosed in Patent Document 1 and Patent Document 2 has made it possible to suppress the scale adhesion particularly in a container in which a polymerization reaction occurs, as compared with the conventional case. Further, the technologies disclosed in Patent Document 3 and Patent Document 4 have improved the cleaning property even for scale adhesion that cannot be suppressed. On the other hand, it has been found that the effects may not be fully exerted in certain cases. This is a case where the treatment liquid containing the toner resin and the liquid medium is discharged from the container at a high temperature.

The wet manufacturing method often includes the step of discharging the processing liquid containing the toner resin and the liquid medium from the reaction container or the storage container to the outside of the container. At this time, when the temperature of the treatment liquid is high, the treatment liquid is generally cooled in the container and then discharged outside the container. On the other hand, in recent years, there are an increasing number of cases in which it is desired to discharge the treatment liquid at a high temperature, and various techniques have been disclosed. For example, a technique of discharging a treatment liquid heated in a container in order to reduce environmental load at a high temperature and cooling the treatment liquid by a heat exchanger while using the slurry as a heat source for heating the slurry before heating in the next batch. Etc. are disclosed. Further, in a method of producing a toner containing a crystalline resin, a technique of discharging the treatment liquid from the container at a high temperature and rapidly cooling it by a heat exchanger provided outside the container is disclosed as a means for controlling the crystallinity. ing. It has been found that in the case where the treatment liquid is discharged from the container at a high temperature as described above, the scale adhesion is not suppressed and the cleaning effect is not sufficiently exhibited even by using the prior art.

An object of the present invention is to reduce scale adhesion in a container in a toner manufacturing method including a step of discharging a treatment liquid containing a toner resin and a liquid medium to the outside of a container at a high temperature. As a result, toner particles can be obtained in a high yield, a high process operation rate can be secured, and unintended contamination of adhering substances can be prevented in subsequent batches, and toner particles of stable quality for a long period of time can be obtained. It is to provide a method for producing toner particles for obtaining the toner.

In order to solve the above problems, the method for producing toner particles of the present invention is
Housed in the container, a manufacturing method of the toner particles comprising a discharge step of discharging the processing liquid containing toner particles and a liquid medium containing the binder resin for toner to the outside of the container,
The binder resin for the toner is a polymer produced by a polymerization reaction of a polymerizable monomer containing styrene,
The container is equipped with a temperature controller used to control the temperature of the processing liquid,
In the discharging step,
When the standard boiling point of water which is the main component of the liquid medium is Bp° C.,
After cooling the temperature controller to (Bp-40)° C. or lower, discharge of the treatment liquid is started,
Temperature of the treatment liquid when the discharge to the outside of the container is started is less than (Bp-40) ℃ higher Bp ° C.,
While the liquid level of the treatment liquid is lowered by discharging the treatment liquid to the outside of the container, a cleaning liquid is sprayed on the inner wall of the container so as to suppress the drying and solidification of the treatment liquid, and water is used as the cleaning liquid. It is characterized in that a cleaning liquid containing it is used.

According to the present invention, in a toner manufacturing method including a step of discharging a treatment liquid containing a toner resin and a liquid medium at a high temperature to the outside of a container, it is possible to reduce scale adhesion in the container. As a result, toner particles can be obtained in a high yield, a high process operation rate can be secured, and unintended contamination of adhering substances can be prevented in subsequent batches, and toner particles of stable quality for a long period of time can be obtained. It is possible to provide a method for producing toner particles for obtaining the above.

It is a schematic sectional drawing which shows an example of the container which can be used for this invention.

Hereinafter, modes for carrying out the present invention will be described, but the present invention is not limited thereto.
The method for producing toner particles according to the present invention is a method for producing toner particles, which includes a discharging step of discharging a treatment liquid containing a resin for toner and a liquid medium contained in a container to the outside of the container. Such a manufacturing method is mainly used in a wet manufacturing method, and specific examples thereof include a suspension polymerization method, an emulsion polymerization method, a dissolution suspension method, and a dispersion polymerization method. In these manufacturing processes, it is general that the treatment liquid containing the toner resin and the liquid medium is housed in a container and stored, or reacted in the container to manufacture toner particles. After being stored or reacted in the container for a required period, the treatment liquid is discharged to the outside of the container for use.

Here, the toner resin in the present invention refers to a high molecular weight organic compound having a weight average molecular weight (Mw) of 300 or more, which constitutes toner particles, such as a binder resin and a release agent. Therefore, even when the high molecular weight organic compound is dissolved or melted in the manufacturing process, it is treated as a toner resin. On the other hand, since the polymerizable monomer before the polymerization reaction is not a polymer, it is treated as not a resin for toner.
The liquid medium is a polymerizable monomer, a liquid medium for dissolving the toner resin, a liquid medium for dissolving the toner particles, a dispersion medium for dispersing the toner resin, and the toner particles. Dispersion medium, etc.

Further, in the present invention, when the standard boiling point of water , which is the main component of the liquid medium , is Bp° C., the temperature of the treatment liquid at the time when the discharge to the outside of the container is started is (Bp-40)° C. Including a discharge step of Bp° C. or higher. Here, the main component of the liquid medium is a substance that occupies 50% by weight or more of the total weight of the liquid medium when the liquid medium contains a plurality of types of substances. As described above, it has been found that there are cases in which the effect of suppressing scale adhesion is not sufficiently exerted even when the prior art is used.

In order to solve this problem, the present inventor examined the mechanism under which this phenomenon occurs, and its countermeasures. As a result, it has been found that the effect of suppressing scale adhesion is not sufficiently exhibited even when the prior art is used when the treatment liquid containing at least the resin for toner or the liquid medium is discharged from the container at a high temperature. In particular, it has been found that this phenomenon occurs remarkably as the temperature of the treatment liquid at the time of discharging the treatment liquid becomes closer to the standard boiling point of water which is the main component of the liquid medium.

When the processing liquid is discharged from the container, it is inevitable that the processing liquid, bubbles and the like remain wet on the inner wall of the container and the members inside the container. At this time, when the temperature of the treatment liquid is low, even if the treatment liquid and bubbles remain wet, scale hardly adheres. On the other hand, it has been found that when the temperature of the treatment liquid is high, the liquid medium evaporates from the treatment liquid and bubbles that remain unwetted, and the toner resin contained in the treatment liquid is dried and solidified to form scale adhesion. In particular, when the standard boiling point of water , which is the main component of the liquid medium in the treatment liquid , is Bp° C., this problem becomes remarkable when the temperature of the treatment liquid is (Bp-40)° C. or higher, and the temperature of the treatment liquid is increased. It was found that the problem becomes more significant as is closer to Bp°C.

From this, it was considered that as a countermeasure, it is important to suppress the wetting residue when discharging the processing liquid and to prevent the evaporation of the liquid medium contained in the processing liquid.
As a technique for suppressing the residual wetting, a material having a large contact angle is used to coat the inner wall of the container or the surface of the member to make it difficult to wet, or the liquid surface lowering speed of the processing liquid is slowed to reduce the wet film thickness. The technology is generally known. The present inventor first conducted an examination focusing on these techniques. As a result, although a certain effect was observed, it was difficult to sufficiently suppress the residual wetting. Further, the coating of the production equipment is not cost-friendly, and it is not preferable to reduce the liquid level lowering rate from the viewpoint of obtaining high productivity.

As a result of further study by the inventor, the cleaning liquid is sprayed on the inner wall of the container while suppressing the liquid level of the processing liquid by discharging the processing liquid to the outside of the container while suppressing the drying and solidification of the processing liquid. It was found that this could solve the problem. This is because by exposing the unwetted surface due to the decrease in the liquid level due to discharge and contacting the cleaning liquid with the liquid, it is possible to perform cleaning before the liquid medium evaporates and the viscosity rises, and it is possible to suppress the unwetted residue. It is thought that it depends. Further, it is speculated that the spraying of the cleaning liquid also raises the humidity in the container at the portion where the cleaning liquid cannot come into contact, and as a result, it can be achieved by slowing the evaporation rate of the liquid medium.

An example of a container that can be used in the present invention is shown in FIG. 1, and a cleaning liquid is discharged onto the inner wall of the container while suppressing the drying and solidification of the processing liquid while discharging the processing liquid to the outside of the container, which is a feature of the present invention. The method of spraying will be specifically described. However, the present invention is not limited to this.

The container 1 in FIG. 1 is a container for storing or reacting a treatment liquid for producing toner particles, and the material etc. is not particularly limited as long as it is a container that does not unintentionally leak to the outside, but is made of metal. Alternatively, a resin container is used. If necessary, the contact surface with the treatment liquid may be lined with glass or PTFE (polytetrafluoroethylene). In the present invention, the processing liquid 2 contained in the container 1 contains at least a resin for toner and a liquid medium. When the processing liquid is discharged from the container, the discharging means that can be used in the present invention can be arbitrarily selected as long as the liquid level 3 is lowered with discharging.

FIG. 1 shows an example in which a discharge valve 4 is installed in the lower part of the container 1 and the processing liquid is discharged by its own weight when the discharge valve 4 is opened, but other means such as pumping up may be used. good. On the other hand, the problem that the present invention intends to solve does not occur in the means in which the liquid surface does not decrease with the discharge, for example, in the means for causing the overflow. The longer the time required for discharging, the more easily scale adhesion due to drying and solidification occurs, and depending on the amount of the processing liquid, the discharging means, and the temperature of the processing liquid, the scale adhesion becomes remarkable when 3 minutes or more is required for discharging.

Although the liquid surface 3 is lowered when the processing liquid 2 is discharged from the container 1, it is inevitable that the processing liquid 2 remains wet on the container inner wall 5, the stirring blades 6, and other members inside the container. In the past, since the treatment liquid was often sufficiently cooled and then discharged, the wet residue of the treatment liquid or the like was not immediately dried and solidified to form scale deposits. Therefore, the subject of the present invention did not occur even if the processing liquid of the next batch was received after the discharge was completed or the inside of the container was washed after the discharge was completed.

On the other hand, as described above, in recent years, there are increasing cases in which it is desired to discharge the treatment liquid at a high temperature. In such a case, if there is a wet residue of the treatment liquid or the like, the liquid medium evaporates from the wet treatment liquid and the toner resin is dried and solidified to easily form scale adhesion. In particular, it was found that this problem becomes remarkable when the temperature of the treatment liquid is (normal boiling point-40)°C or higher of the main component of the liquid medium, and the problem becomes larger as the temperature approaches the normal boiling point.

When the viscosity of the treatment liquid is high, when it contains bubbles, or when the liquid surface lowering speed is high, the thickness of the remaining unwetted layer is further increased and the problem of scale adhesion becomes serious. In the present invention, the cleaning liquid can be sprayed into the container by means of, for example, installing the cleaning liquid spray nozzle 7 in the container, and the cleaning liquid is sprayed while discharging the processing liquid. The cleaning liquid can be contacted at the same time as the exposure. When the unwetted surface is exposed and the cleaning liquid is brought into contact with the unwetted surface at the same time, it is possible to perform the cleaning before the liquid medium evaporates from the unwetted residue and the viscosity increases, so that the unwetted residue can be suppressed. Further, even if there is a portion where the cleaning liquid cannot come into contact, by spraying the cleaning liquid, the evaporation rate of the liquid medium becomes slower and the drying and solidification can be suppressed.

The discharge speed of the processing liquid at the time of discharging may be arbitrarily controlled as necessary. For example, the discharge speed can be controlled by adjusting the pressure in the container, the opening degree of the discharge valve 4, the rotation speed of the pump installed in the discharge line 8. Can be slow or fast. When the discharging speed is slow, the lowering speed of the liquid surface becomes slower, so that the wet residue of the treatment liquid can be reduced. On the contrary, when the discharge speed is increased, the wet residue increases, but by adopting the configuration of the present invention, the dry solidification of the wet residue can be suppressed.

The means for spraying the cleaning liquid, the supply speed, and the supply pressure are not particularly limited as long as they can uniformly contact the inner wall of the container or the inner member of the container with the cleaning liquid. For example, it may be sprayed manually with a hose, or the cleaning liquid spray nozzle 7 connected to the supply source of the cleaning liquid may be installed in the container and sprayed only by opening and closing the valve. When the cleaning liquid spraying nozzle is installed, it is preferable to arrange a plurality of cleaning liquid spraying nozzles so that there is no blind spot. The supply speed and pressure of the cleaning liquid depend on the size of the container, the shape of the spray nozzle, and the like, but it is sufficient that the cleaning liquid can evenly contact the inside of the container and the members inside the container.

For example, the supply pressure of the cleaning liquid can be 0.1 MPa or more, which is the same pressure as that of general water supply, and the supply rate can be 2 L/min or more per 1 square meter of the area of the cleaning object. When the solid content or viscosity of the treatment liquid is high, or when the wet residue is thick due to bubbles or the like, the cleaning liquid supply rate and pressure are preferably as high as possible, but it is not necessary to use a special high pressure as in the prior art.

The supply rate of the cleaning solution needs to be slower than the discharge rate of the processing solution. When the supply speed of the cleaning liquid exceeds the discharge speed of the processing liquid, the amount of liquid in the container increases, which causes liquid overflow. When it is desired to increase the supply rate per unit time, it is possible to use a means such as intermittently spraying the cleaning liquid within a range where the treatment liquid does not dry and solidify. Even when it is not necessary to increase the supply rate, intermittent spraying of the cleaning liquid is preferable from the viewpoint of reducing the amount of the cleaning liquid as much as possible.

The type of the cleaning liquid to be sprayed is not particularly limited, but it is preferable to use the same liquid medium as the treatment liquid or a liquid medium mixed in the next step. For example, the main component of the liquid medium may be used as a single substance, a mixture of the main component and a subcomponent, or a substance having improved cleaning properties by adding a surfactant or the like may be used.

The temperature of the cleaning liquid can be arbitrarily selected depending on the properties of the treatment liquid or the crystallinity control of the crystalline resin, but from the viewpoint of the effect of the present invention, the heated cleaning liquid is preferable. When the temperature of the cleaning liquid is high, the effect of cleaning the wet treatment liquid is improved, and it also meets the demand that the temperature of the treatment liquid should not be lowered. From the viewpoint of improving the cleaning effect, the temperature of the cleaning liquid is preferably 30° C. or higher, and is preferably Bp° C. or lower from the viewpoint of suppressing the drying of wet residue. Further, it is particularly preferable to use a cleaning liquid heated to the same temperature as that of the processing liquid from the viewpoint of preventing the processing liquid temperature from decreasing. However, as described above, it may be preferable from the viewpoint of the performance of the toner particles that the cleaning liquid is not heated, such as the property of the treatment liquid and the crystallinity of the crystalline resin, and thus it can be arbitrarily selected.

Examples of the in-container member 6 include a stirring blade, a baffle for the purpose of 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 Maxblend blade.

When the container is equipped with a temperature controller, it is preferable to start cooling the temperature controller before discharging. Examples of the temperature controller include the temperature adjustment jacket 9 and the temperature adjustment coil illustrated in FIG. The temperature controller is used as a heating/cooling source of the processing liquid. If the processing liquid is discharged while the temperature of the temperature controller is high, the evaporation rate of the liquid medium in the vicinity of the temperature controller is high and the scale adheres significantly. It is particularly preferable to cool the temperature controller to (Bp-40)° C. or lower and then discharge the temperature controller, because drying and solidification in the vicinity of the temperature controller can be suppressed. More preferably, the discharge is started after the temperature of the temperature controller falls below the glass transition temperature (Tg) of the toner resin.

By setting the temperature to the glass transition temperature or lower, it is possible to prevent the scale adhesion and fusion even if the residual wetting cannot be suppressed. When the treatment performed in the vessel is a polymerization reaction, it is important to prevent the adhesion to the temperature controller. Since the heat transfer is hindered when the scale adheres to the temperature controller, the temperature increase/decrease rate is delayed as the batch is piled up, or the desired temperature cannot be maintained and the temperature control becomes unstable. In the polymerization reaction, it is important to control the treatment temperature because the temperature affects the polymerization rate. If the polymerization rate is not uniform between different batches, the toner particles produced will have different molecular weights, making it impossible to obtain stable fixing toner particles.

When the temperature at the start of discharging the processing liquid is T1° C. and the temperature at the end of discharging the processing liquid is T2° C., the temperature of the cleaning liquid and the temperature controller of the temperature controller are adjusted so that T1−T2≦10.0° C. It is preferable to perform the discharge while controlling the temperature. When the discharge is started after the cooling of the temperature controller provided in the container is started, the temperature of the treatment liquid may decrease, but it is not necessary to continue the cooling even after the discharge is started. For example, by holding the resin for toner near the glass transition temperature, it is possible to suppress the fusion of the wet residue of the treatment liquid and also to prevent the temperature of the treatment liquid from rapidly decreasing. Further, the temperature of the processing liquid can be prevented from lowering by raising the temperature of the cleaning liquid. In order to discharge the treatment liquid at a high temperature, it is possible to suppress the temperature drop of the treatment liquid by adopting the above means.

Furthermore, when the container is equipped with a stirring device, it is preferable to start discharging while stirring the processing liquid. Even when the treatment liquid contains bubbles or has thixotropy, it is possible to suppress an increase in the wet film thickness by discharging the treatment liquid while stirring. However, when the processing liquid is discharged by its own weight from the discharge valve provided at the bottom of the container, the discharging speed may slow down due to the relationship between the centrifugal force due to stirring and the weight, so adjust the stirring speed if necessary. To do.

Here, as a representative example, a detailed mode for carrying out the present invention will be described using an example of obtaining a toner particle dispersion liquid by a suspension polymerization method.
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, a liquid medium and additives are added to a dissolution container, and an arbitrary stirrer is added. Or a disperser to prepare a polymerizable monomer composition that is uniformly dissolved or dispersed. At this time, the polymerizable monomer composition may be heated in order to accelerate the dissolution of the toner resin and to uniformly mix the toner resin. As a heating means, a known method can be selected, and examples thereof include a temperature adjusting jacket, a temperature adjusting coil, and a method of attaching electromagnetic induction heating to a melting container.

The temperature for heating in the dissolution step can be selected according to the solid-liquid ratio and the melting point of the release agent, but is preferably 50° C. or higher and 130° C. or lower. 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 that is the treatment liquid is heated, the temperature of the treatment liquid may become inhomogeneous due to precipitation of the resin for the toner, etc. It is preferable to discharge without lowering the temperature. When the temperature of the treatment liquid at the time of discharge is equal to or higher than the normal boiling point of the main component of the liquid medium −40° C., the constitution of the present invention is adopted, that is, when the cleaning liquid is sprayed into the dissolution container while being discharged, it is dried. Scale adhesion due to solidification can be suppressed.

The cleaning liquid used at this time is preferably used when the main component of the liquid medium is a polymerizable monomer. Alternatively, it is also preferable to use water that will be mixed in the next granulation step. If necessary, a solvent capable of dissolving the toner resin or a cleaning liquid mixed with a surfactant can be used. Further, it is preferable that the temperature of the cleaning liquid in the dissolving step is heated so that precipitation of the residual toner resin does not occur.

The above-mentioned polymerizable monomer composition sent to the granulation step is mixed with an aqueous phase containing a dispersant prepared in advance in a granulation container, and an arbitrary agitator having a high shearing force. And a disperser to form droplets of the polymerizable monomer composition into desired toner particle sizes. 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. That is, water is the main component of the liquid medium in the granulation step described in this representative example.

The granulation step is preferably performed in a heated state to prevent precipitation of the toner resin, and the temperature is preferably 40° C. or higher and 100° C. or lower depending on the solid-liquid ratio and the melting point of the release agent. If necessary, the granulation step can be performed while the inside of the granulation container is pressurized. The treated liquid after granulation is discharged from the container and sent to the next polymerization step. Since the main component of the liquid medium in this representative example is water, when the treatment liquid is discharged at a standard boiling point of water of 100° C. to 40° C., that is, 60° C. or higher, scale adhesion due to drying and solidification easily occurs. It is preferable to adopt the configuration of the present invention. Water, which is the main component of the liquid medium, is preferably used as the cleaning liquid, and the temperature is preferably warmed to a temperature at which precipitation of the toner resin does not occur.

In the polymerization step, the treatment liquid is heated in the polymerization container to advance the polymerization reaction. The polymerization temperature is set to 40° C. or higher, generally 50 to 95° C. to carry out the polymerization. In order to improve the low-temperature fixability of the toner particles, it is possible to obtain a polymer having a low molecular weight by pressurizing the inside of the polymerization container to heat it to a temperature higher than the normal boiling point of water. When the polymerization initiator is added, it can be carried out at any time and for a required time after the polymerizable monomer composition is prepared. Further, the temperature may be raised in the latter half of the polymerization reaction for the purpose of obtaining a desired molecular weight distribution.

In the polymerization step, the temperature of the treatment liquid has a great influence on the fixing performance of the toner particles, and therefore the stirring operation is generally performed so that the temperature distribution in the container becomes uniform. In addition, it is necessary to pay particular attention to scale adhesion to the temperature controller in the polymerization process. As the scale adheres to the temperature controller, heat transfer to the container is hindered, which makes it difficult to control the temperature of the processing liquid. Therefore, it becomes difficult to obtain toner particles having stable fixing performance for a long period of time. The treatment liquid in which the polymerization reaction has proceeded to the desired polymerization rate is discharged from the polymerization container and sent to the next step.

The treatment liquid that has completed the polymerization reaction contains toner particles, a dispersant, and water as a dispersion medium, and the main component of the liquid medium is water. When removing unreacted polymerizable monomers and byproducts from the system in the next step, a distillation operation is performed. Since the distillation operation is performed at a high temperature near the normal boiling point of water, it is preferable not to lower the temperature of the treatment liquid discharged from the polymerization vessel. In addition, it is also preferable to discharge the treatment liquid at a high temperature for the purpose of reusing the heat of the treatment liquid at high temperature and for controlling the crystallinity of the generated polymer or crystalline material.

For these purposes, even when the treatment liquid is discharged at a high temperature, when the treatment liquid is discharged at a standard boiling point of water of 100° C. to 40° C., that is, 60° C. or higher, the scale adheres due to drying and solidification. Since it is likely to occur, it is preferable to adopt the configuration of the present invention. It is preferable to use water, which is the main component of the liquid medium, as the cleaning liquid. Further, since it is important to suppress scale adhesion to the temperature controller in the polymerization step, it is preferable to start cooling the temperature controller before starting discharging. Further, it is particularly preferable from the viewpoint of suppressing fusion that the temperature of the temperature controller is cooled to the glass transition temperature of the toner particles or lower before discharging.

A vinyl-based polymerizable monomer capable of radical polymerization is preferably used as the polymerizable monomer used for the toner particles in the suspension polymerization method. As the vinyl-based 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, vinyl esters such as vinyl acetate, and the like. Among these, the present invention is more suitable for suppressing scale adhesion and coarse particles in the method for producing toner particles using styrene alone or a combination of two or more kinds of styrene and other polymerizable monomers. Can be used.

As the colorant used for the toner particles in 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; 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 in the suspension polymerization method, a wax in a solid state at room temperature is preferable in terms of toner blocking resistance, multi-sheet durability, low temperature fixing property, and offset resistance. Examples thereof include paraffin wax, microcrystalline wax, Fischer-Tropsch wax, ester wax and the like. In order to improve the translucency of the image fixed on the OHP, 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 being dispersed in the polymerizable monomer composition or the like. It is also possible. Examples of the charge control agent having negative chargeability include organometallic compounds and chelate compounds, and examples of the charge control agent having positive chargeability include nigrosine and amine compounds.

As a polymerization initiator used for toner particles in the suspension polymerization method, for example, potassium peroxodisulfate, hydrogen peroxide solution, 2,2′-azobis-(2,4-dimethylvaleronitrile), benzoyl peroxide, t-butylperoxide. Examples include oxylaurate.
Examples of the cross-linking agent include polyfunctional compounds such as divinylbenzene, 4,4′-divinylbiphenyl, and ethylene glycol di(meth)acrylate.

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

In the case of a polymerization method using an aqueous dispersion medium such as suspension polymerization, addition of a polar resin to the polymerizable monomer composition can promote the inclusion of the release agent. 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 the 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 becomes good.

In addition, by selecting a polar resin with a high melting temperature for the shell part, even if the binder resin of the core part is designed to be melted at a lower temperature for the purpose of low-temperature fixing, adverse effects such as blocking during storage may occur. Can be suppressed. As such a polar resin, a saturated or unsaturated polyester resin is particularly preferable because 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 liquid thus obtained is sent to a solid-liquid separation/washing step. At that time, the toner particle dispersion liquid may be treated with an acid or an alkali for the purpose of removing the dispersion stabilizer adhering to the surfaces of the toner particles. After that, 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, 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, classified to separate a group of particles having a particle size outside the predetermined range. The non-predetermined particle group separated at this time 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-mentioned polymerization method or other external additives may be externally added to the toner particles for the purpose of imparting various characteristics to the toner. The external additive preferably has a particle diameter of 1/10 or less of the volume average particle diameter of the toner particles from the viewpoint of durability when added to the toner. Examples of the external additive 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 and silica. Is used.

The toner produced by the present invention can be used as any one-component and two-component developer for any developer. For example, in the case of a magnetic toner containing a magnetic material in toner particles as a one-component developer, there is a method of using a magnet built in a developing sleeve to convey 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, and the developing sleeve is forcibly triboelectrically charged so that the toner adheres to the sleeve for conveyance.

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 composed mainly of iron, copper, zinc, nickel, cobalt, manganese, and chromium elements in a single or composite ferrite state. Generally, a method is used in which carrier core particles are generated in advance by firing and granulating the above-mentioned inorganic oxide, and then coating with a resin. In order to reduce the load on the toner of the carrier, a method of kneading the inorganic oxide and the resin, pulverizing and classifying the resin to obtain a low-density dispersed carrier, and a method of suspending the mixture of the inorganic oxide and the monomer in an aqueous medium are used. It is also possible to use a method of obtaining a polymerization carrier by suspension polymerization.

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

(1) Evaluation of Yield/Measurement of Amount of Scale Deposits In order to evaluate the yield improving effect, the amount of scale deposits is quantified. The scale adhesion is originally a product, and the smaller the scale adhesion, the better the yield. Place a test piece in the container to measure the amount of scale deposits. An aluminum plate having a length of 100 mm×a width of 50 mm×a thickness of 2 mm is used as the test piece.

As shown in 10 of FIG. 1, four test pieces were set on the upper and lower portions of the liquid surface at the opposite positions on the inner wall of the container, and after one batch of toner particles was manufactured, the test piece was removed from the container, immersed in water, and lightly washed with water. Let dry and weigh. The difference from the weight of the test piece before the production of the toner particles is taken, and the total amount of change in the weight of the four test pieces is taken as the amount of scale deposits. The evaluation is obtained by calculating the ratio of the amount of scale deposits to the total weight of the polymerizable monomer composition mixed in the <dissolving step> described later.

A: Very good level (scale deposit amount is less than 500 ppm)
B: Good level (scale deposit amount is 500 ppm or more and less than 3000 ppm)
C: No problem level (scale deposit amount is 3000 ppm or more and less than 6000 ppm)
D: Acceptable level (scale deposit amount is 6000 ppm or more and less than 10,000 ppm)
E: Poor level (scale deposit amount 10,000 ppm or more)

(2) Stability Evaluation of Thermal Properties of Toner Particles In the polymerization process, the thermal properties of the toner particles are stable for a long period of time by suppressing the scale adhesion to the temperature controller. A melt index value at a temperature of 110° C. and a load of 10 kg is used as an index of the toner particle thermal characteristics. The melt index value represents the easiness of melting of toner particles at an arbitrary temperature and load, and can be used as an index of thermal characteristics when fixing 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 refers to the discharge amount from the orifice in 10 minutes at an arbitrary temperature and load. In this example, the values are measured under the following conditions. This basically complies with <JIS K-7210>.
A Semi-automatic 2-A Melt Index (Toyo Seiki Co. Ltd) is used as a measuring device.
An orifice having a cavity inner diameter of 2.095 mm is put in, the temperature is adjusted to 110° C. in advance, and 3 to 8 g of the toner particle sample is weighed and put therein. At this time, be careful not to let air bubbles enter, set the metal piston and keep the temperature for 5 minutes or more. Then, the measurement is performed while applying a constant load such that the total of the piston and the weight is 10 kg. The measurement may be performed at an arbitrary time and converted into a discharge amount for 10 minutes.

To evaluate the stability of the thermal characteristics of the toner particles, toner particles are prepared while depositing scale deposits by preparing 10 batches of toner particles continuously using the same polymerization container. The melt index value of the toner particles for 10 batches thus obtained is measured, and the standard deviation is evaluated.

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: No problem level (standard deviation is 1.0 or more and less than 2.0)
D: Acceptable level (standard deviation is 2.0 or more and less than 4.0)
E: Bad level (standard deviation is 4.0 or more)

(3) Evaluation of Image Performance/Evaluation of Image Black Spots If scale deposits are formed, unintended mixing into the subsequent batch or later is caused. As a result, black spots are likely to occur. To 100 parts by mass of the toner particles, 3 parts by mass of hydrophobic silica having a specific surface area according to the BET method of 200 m ² /g was externally added to obtain a toner. Using this toner as a one-component developer, LBP5800 (manufactured by Canon Inc.) was used for evaluation.
First, 100 g of the obtained toner was filled in a cartridge, and in a durability test (repeated use test) under a low temperature and low humidity environment (temperature 15° C./relative humidity 10%), a fixing roller and an image after printing 10,000 sheets Was visually confirmed and evaluated as shown below.

A: No toner adhesion is seen on the fixing roller, and no black spots are seen.
B: Toner adhesion is seen on the fixing roller, but it does not appear on the image.
C: One or two black spots are seen on the image.
D: Three or more black spots are seen on the image.

[Example 1]
<Dissolution process>
The following materials were heated to 60° C. in a dissolution vessel and dissolved and mixed for 30 minutes to prepare a polymerizable monomer composition.
-Styrene monomer 70 parts by mass-n-butyl acrylate 30 parts by mass-Saturated polyester resin (polycondensate of propylene oxide-modified bisphenol A (2 mol addition product) 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 (manufactured by 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 Salicylic acid compound E-88 (manufactured by Orient Chemical Industry Co., Ltd.) 1 part by mass Zinc phthalocyanine 0.1 part by mass The following materials were mixed in a solution obtained by dissolving and mixing for 30 minutes.
-Polymerization initiator 2,2'-azobis(2,4-dimethylvaleronitrile) 8 parts by mass

The polymerizable monomer composition that had been dissolved and mixed was discharged from the dissolution vessel at 60° C. without lowering the temperature and transferred to the granulation step. The main component of the liquid medium in this example is styrene monomer (normal boiling point 145° C.), and the temperature of the treatment liquid at the time of discharge is 60° C. After the transfer to the granulation step was completed, warm water at 80° C. was sprayed into the dissolution container to wash the remaining wet. Although the discharging step took 20 minutes, scale adhesion could be suppressed by spraying warm water after the discharging was completed. It is considered that this is because the temperature of the treatment liquid was less than “boiling point of main component of liquid medium −40° C.”.

<Granulation process>
After warming to _Na 3 _PO 4 · 12H ₂ O 5 parts by mass turned to 60 ° C. in deionized water 332 parts by weight, per 58.3 rotate with Clearmix (manufactured by M Technique (Ltd.)) (3500 rpm ) Stirred. To this, 27 parts by mass of 1.0 mol/liter-CaCl ₂ aqueous solution was added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

The polymerizable monomer composition was put into the aqueous medium and stirred at a temperature of 60° C. under N ₂ atmosphere with Clearmix at 4500 rpm for 15 minutes to granulate the polymerizable monomer composition. The treatment liquid after granulation was discharged from the granulation container at 60° C. without lowering the temperature and transferred to the polymerization step. In the granulation step in this example, 332 parts by mass of ion-exchanged water (normal boiling point 100° C.) is the main component of the liquid medium, and the temperature of the treatment liquid at the start of discharging is 60° C.

At the time of discharge, at the same time as starting the transfer to the reaction step, spraying warm water at 60° C. into the granulation container as a cleaning liquid. As a nozzle for performing hot water spraying, four spiral jet holocon spray B1/4BSJ-SS18013 (manufactured by Spraying Systems Japan Co., Ltd.) were installed in the granulation container. The supply pressure of the hot water for cleaning was 0.3 MPa, the supply rate was 10 kg/min, the discharge rate of the treatment liquid was 400 kg/min, and the discharge step required 20.5 minutes. It was possible to suppress scale adhesion by spraying warm water while discharging the treatment liquid. Table 1 shows the evaluation results of the yield in the granulation step.

<Polymerization process>
As for the treatment liquid after granulation, as shown in Fig. 1, four spiral jet holocon spray B1/4BSJ-SS18013 (manufactured by Spraying Systems Japan Co., Ltd.) and a temperature control jacket were used as spray nozzles for the cleaning liquid. It was transferred to the equipped polymerization container. After receiving all the treatment liquids from the granulation process, the temperature was raised to 65°C and the polymerization reaction was performed for 10 hours while stirring with a full-zone stirring blade (manufactured by Shinko Environmental Solutions Co., Ltd.), and further at 85°C for 1 hour The molecular weight distribution was adjusted by heating.

After the completion of the polymerization reaction, a cooling medium was allowed to flow through the cooling jacket for cooling, and when the temperature at the cooling outlet of the cooling jacket reached 55° C., discharge of the treatment liquid was started and transfer to the distillation step was started. At this time, the temperature of the treatment liquid was 80°C. In the polymerization step in this example, ion-exchanged water (normal boiling point 100°C) is the main component of the liquid medium, and the temperature of the treatment liquid at the start of discharge is 80°C.

At the time of discharge, at the same time as starting the transfer to the distillation step, spraying warm water at 80° C. into the polymerization container as a cleaning liquid. The supply pressure of the hot water for cleaning 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 rate of the treatment liquid was 400 kg/min, and the discharge step required 20.5 minutes. When the temperature of the treatment liquid at the start of discharge is T1°C and the temperature of the treatment liquid at the end of discharge is T2°C, the temperatures of the hot water and the temperature controller are adjusted so that T1-T2=3.0°C. The temperature of the treatment liquid at the end of discharge was 77°C. It was possible to suppress scale adhesion by spraying warm water while discharging the treatment liquid. Table 1 shows the evaluation results of the yield in the polymerization step.

<Distillation process>
Saturated steam (pure steam/steam pressure 205 kPa/temperature 120° C.) was introduced while stirring the treatment liquid transferred from the polymerization step in a distillation container. Since the temperature of the hot water and the temperature controller were adjusted so that T1-T2=3.0° C. in the polymerization step, the temperature rise in the distillation step reached 100° C. in 20 minutes, and the distillation fraction began to come out. By obtaining a predetermined amount of fraction, the residual monomer was distilled off to obtain a toner particle dispersion liquid. The toner particle dispersion was cooled to 30° C. in a distillation container, discharged, and transferred to a washing/solid-liquid separation/drying step.

In the distillation step in this example, ion-exchanged water (normal boiling point 100°C) is the main component of the liquid medium, and the temperature of the treatment liquid at the start of discharge is 30°C. After the transfer to the next step was completed, water at room temperature was sprayed into the dissolution vessel to wash the remaining wet parts. Although the discharging step took 20 minutes, scale adhesion could be suppressed by spraying with normal temperature water after the discharging was completed. It is considered that this is because the temperature of the treatment liquid at the start of discharge was less than “boiling point of main component of liquid medium −40° C.”.

<Washing/solid-liquid separation/drying process>
Hydrochloric acid was added to the obtained toner particle dispersion liquid and stirred to dissolve Ca ₃ (PO ₄ ) ₂ covering the toner particles, and then solid-liquid separation was performed with a pressure filter to obtain a toner cake. This was put into water, stirred, and made into a dispersion again, followed by solid-liquid separation with the above-mentioned filter. Redispersion 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 crushed and dried by an airflow dryer (manufactured by Seishin Enterprise Co., Ltd.: flash jet dryer: pipe diameter 0.1016 m) to obtain toner particles. The drying conditions were a blowing temperature of 90° C., a blowing air volume of 10 m ³ /min, a dryer outlet temperature of 40° C., and the toner cake supply rate was adjusted to a rate at which 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 stability evaluation method of thermal characteristics of toner particles. The results are shown in Table 1. Further, the toner particles obtained in the 10th batch were evaluated according to the above-described image performance evaluation method. The results are shown in Table 1.

[Example 2]
In the polymerization step, after the completion of the polymerization reaction, a cooling medium was flown into the temperature control jacket to start cooling, and the temperature of the temperature control jacket was maintained at 55° C. when the temperature of the refrigerant outlet of the temperature control jacket reached 55° C. The treatment liquid was cooled as it was, and when the temperature of the treatment liquid reached 61° C., discharging of the treatment liquid was started and transferred to the distillation step.
At the time of discharging, at the same time as starting the transfer to the distillation step, spraying warm water at 61° C. into the polymerization container as a cleaning liquid.
The temperature of the cleaning liquid and the temperature of the temperature controller were adjusted so that T1−T2=3.0° C., and the temperature of the processing liquid at the end of discharge was set to 58° C. Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Example 3]
In the polymerization step, after the completion of the polymerization reaction, a heating medium was flown through the temperature control jacket to heat the treatment liquid to 98°C. After that, a cooling medium was caused to flow through the temperature control jacket for cooling, and when the temperature of the refrigerant outlet temperature of the temperature control jacket reached 55° C., discharging was started and transferred to the distillation step. At this time, the temperature of the treatment liquid was 95°C.
At the time of discharge, at the same time as starting the transfer to the distillation step, spraying warm water at 95° C. into the polymerization container as a cleaning liquid.
The temperature of the cleaning liquid and the temperature of the temperature controller were adjusted so that T1−T2=3.0° C., and the temperature of the processing liquid at the end of discharge was set to 92° C. Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Example 4]
Non-heated water at 20° C. was sprayed as a cleaning liquid to be sprayed at the discharge of the polymerization step. Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Example 5]
Hot water heated to 95° C. was sprayed as a cleaning liquid to be sprayed at the discharge of the polymerization step. Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Example 6]
Warm water heated to 30° C. was sprayed as a cleaning liquid sprayed at the time of discharge in the polymerization step. Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Example 7]
Before the discharge in the polymerization step, the treatment liquid was discharged without cooling the temperature control jacket. At this time, the temperature of the temperature control jacket was 95°C and the temperature of the treatment liquid was 85°C. Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Example 8]
The temperature control jacket was cooled to 65° C. before discharge in the polymerization step, and then the treatment liquid was discharged. At this time, the temperature of the treatment liquid was 83°C. Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.
Examples 7 to 8 are described as reference examples.

[Example 9]
The temperature control jacket was cooled to 30° C. before discharge in the polymerization step, and then the treatment liquid was discharged. At this time, the temperature of the treatment liquid was 75°C. Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Example 10]
The discharge was carried out while controlling the temperature of the cleaning liquid and the temperature of the temperature control jacket so that T1-T2=12.0° C. during discharge in the polymerization step. The temperature of the treatment liquid at the end of discharge was 68.0°C. Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Example 11]
The discharge was performed while controlling the temperature of the cleaning liquid and the temperature of the temperature control jacket so that T1-T2=9.0° C. during the discharge in the polymerization step. The temperature of the treatment liquid at the end of discharge was 71.0°C. Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Comparative Example 1]
The cleaning liquid was not sprayed at the time of discharging in the granulation step and at the time of discharging in the polymerization step. Since the cleaning liquid was not sprayed, the time required for the discharging step was 20 minutes.
Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Reference Example 1]
After the completion of the polymerization reaction in the polymerization step, the refrigerant was continuously flown into the temperature control jacket before discharging to cool the temperature control jacket to 10°C. The treatment liquid was cooled as it was, and when the temperature of the treatment liquid reached 55° C., discharge of the treatment liquid was started and transfer to the distillation step was started.
The cleaning liquid was not sprayed during discharging, and the discharging process took 20 minutes.
Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.

[Reference Example 2]
The temperature control jacket was not cooled during discharge in the granulation step and before discharge in the polymerization step, and the cleaning liquid was not sprayed during discharge. Since the cleaning liquid was not sprayed, the time required for the discharging step was 20 minutes.
Warm water at 80° C. was sprayed as a cleaning liquid 5 minutes after the discharge in the granulation step was completed and 5 minutes after the discharge in the polymerization step was completed.
In the present reference example, the supply pressure, supply rate, and supply amount of the hot water that was sprayed after the end of discharge were the same as the supply pressure, supply speed, and supply amount of the warm water that was sprayed at the time of discharge in Example 1.
Except for this, toner particles were produced in the same manner as in Example 1. The evaluation results are shown in Table 1.

As is clear from Table 1, Examples 1 to 11 were able to suppress scale adhesion as compared with Comparative Example 1. The toner particles obtained in Examples 1 to 11 have stable thermal characteristics and image performance.

1 container 2 processing liquid 3 liquid level
4 Discharge valve 5 Inner wall of container 6 Inner member of container 7 Cleaning liquid spraying nozzle 8 Discharge line 9 Jacket for temperature control 10 Test piece

Claims (3)

Housed in the container, a manufacturing method of the toner particles comprising a discharge step of discharging the processing liquid containing toner particles and a liquid medium containing the binder resin for toner to the outside of the container,
The binder resin for the toner is a polymer produced by a polymerization reaction of a polymerizable monomer containing styrene,
The container is equipped with a temperature controller used to control the temperature of the processing liquid,
In the discharging step,
When the standard boiling point of water which is the main component of the liquid medium is Bp° C.,
After cooling the temperature controller to (Bp-40)° C. or lower, discharge of the treatment liquid is started,
Temperature of the treatment liquid when the discharge to the outside of the container is started is less than (Bp-40) ℃ higher Bp ° C.,
While lowering the liquid level of the treatment liquid by discharging the treatment liquid to the outside of the container, a cleaning liquid is sprayed on the inner wall of the container so as to suppress drying and solidification of the treatment liquid,
A method for producing toner particles, wherein a cleaning liquid containing water is used as the cleaning liquid. The method for producing toner particles according to claim 1, wherein the sprayed cleaning liquid is heated to 30° C. or higher and Bp° C. or lower. When the temperature at the start of discharging the treatment liquid is T1° C. and the temperature at the end of discharging the treatment liquid is T2° C., the temperature of the cleaning liquid and the temperature are such that T1−T2≦10.0° C. method for producing toner particles according to claim 1 or 2 to discharge while controlling the temperature of the control.

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