Heat treatment device and toner manufacturing method

Abstract

To provide a technique that can prevent, with a simple configuration, fusion of toner particles to a wall surface inside a processing chamber and coalescence and cohesion of toner particles to improve the productivity of toner particles having desired circularity.SOLUTION: Heat treatment equipment comprises: a processing tank that has a processing chamber for executing heat treatment on toner particles; toner particle supply means that supplies the toner particles to the inside of the processing chamber; and hot wind supply means that has a supply port for supplying hot air to the inside of the processing chamber. The hot air supply port is arranged on the ceiling of the processing chamber. The processing tank has a columnar member that is erected in the vertical direction at the center inside the processing chamber, and a convex member having a substantially conical shape that is provided at an upper end of the columnar member and projects toward the ceiling. The columnar member has a cylindrical shape and has a radius of curvature RCP (mm) of 5<RCP<75 at an upper end edge on a vertical section.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a heat treatment device used for spheronizing toner particles. [Background technology]

[0002] In the manufacturing process of toner used as a developer in electrophotographic image forming devices, a heat treatment is sometimes performed to make toner particles spherical to a desired circularity (spheronization treatment). One heat treatment device that performs the spheronization treatment is one that creates a hot air current in a treatment chamber of a treatment tank, and moves the toner particles inside the treatment chamber on the hot air current, bringing them into a molten state and changing the circularity of the toner particles to a desired value (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-276016 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-310324 Summary of the Invention [Problem to be solved by the invention]

[0004] Toner particles in a molten state may fuse to the wall surfaces of the processing chamber or coalesce or become cohesive with each other. Such fusion and coalescence of toner particles affect the productivity of toner particles with a desired circularity and the maintainability of the processing device. Patent Document 1 discloses a technique for preventing toner particles from fusing to the wall surfaces of the processing chamber by cooling the wall surfaces of the processing chamber with cooling air. Patent Document 2 also discloses a technique for preventing variations in sphericity and the bonding of toner particles by providing a curved surface of a predetermined shape at the injection nozzle outlet so that larger toner particles are dispersed and supplied upstream of smaller toner particles in the hot air.

[0005] It is believed that the fusion of toner particles to the wall surface of the processing chamber occurs when the toner particles come into contact with the wall surface while in a molten state, and that the coalescence and adhesion of toner particles occurs when the toner particles remain in a molten state for a long time, increasing the opportunities for the toner particles to come into contact with each other. The techniques described in Patent Documents 1 and 2 may not be able to sufficiently prevent such retention of toner particles in a molten state.

[0006] An object of the present invention is to provide a technology that can suppress fusion of toner particles and coalescence or adhesion of toner particles with a simple configuration, thereby improving productivity of toner particles having a desired circularity. [Means for solving the problem]

[0007] In order to achieve the above object, the heat treatment device of the present invention comprises: a treatment tank having a treatment chamber for subjecting the toner particles to a heat treatment; a toner particle supply means for supplying toner particles into the processing chamber; hot air supply means having a supply port for supplying hot air into the inside of the processing chamber; In a processing device comprising: a supply port of the hot air supply means is disposed on the ceiling of the processing chamber; The treatment tank comprises: a columnar member provided vertically in the center of the interior of the processing chamber; a convex member having a substantially conical shape provided at an upper end of the columnar member and protruding toward the ceiling; and The columnar member has a cylindrical shape, and in a vertical cross section, the radius of curvature RCP (mm) of the upper edge is: 5 <RCP<75 It is characterized in that: In order to achieve the above object, a toner manufacturing method according to the present invention is a toner manufacturing method that manufactures a toner by subjecting toner particles to a heat treatment using a heat treatment device, The heat treatment device includes: a treatment tank having a treatment chamber for subjecting the toner particles to a heat treatment; a toner particle supply means for supplying toner particles into the processing chamber; hot air supply means having a supply port for supplying hot air into the inside of the processing chamber; Equipped with a supply port of the hot air supply means is disposed on the ceiling of the processing chamber; The treatment tank comprises: a columnar member provided vertically in the center of the interior of the processing chamber; a convex member having a substantially conical shape provided at an upper end of the columnar member and protruding toward the ceiling; and The columnar member has a cylindrical shape, and in a vertical cross section, the radius of curvature RCP (mm) of the upper edge is: 5 <RCP<75 It is characterized in that: [Effects of the Invention]

[0008] According to the present invention, it is possible to suppress the fusion of toner particles and the coalescence or adhesion of toner particles with a simple configuration, thereby improving the productivity of toner particles having a desired circularity. [Brief explanation of the drawings]

[0009] [Figure 1] Schematic diagram of a thermal sphering device according to embodiment 1 of the present invention. [Figure 2] 1 is a cross-sectional view of a treatment tank according to a first embodiment of the present invention; [Figure 3] FIG. 1 is a perspective view of a treatment tank according to a first embodiment of the present invention; [Figure 4] FIG. 1 is a perspective view of a center pole according to a first embodiment of the present invention; [Figure 5] FIG. 1 is a perspective view of a treatment tank according to a first embodiment of the present invention; [Figure 6] FIG. 1 is an enlarged perspective view of the periphery of the upper end of a center pole according to the first embodiment of the present invention. [Figure 7] 1 is a cross-sectional view of a treatment tank according to a first embodiment of the present invention; [Figure 8] 1 is a cross-sectional view of an upper portion of a processing chamber of a processing tank according to a first embodiment of the present invention and a comparative example; [Figure 9]Schematic diagram showing dimensions of each component of a treatment tank according to a first embodiment of the present invention. [Figure 10] FIG. 1 is a cross-sectional view showing dimensions of components of a treatment tank according to a first embodiment of the present invention. [Figure 11] Schematic diagram of a toner supply port and a first cool air supply port according to the first embodiment of the present invention. [Figure 12] 10 is a cross-sectional view of an upper portion of a treatment chamber of a treatment tank according to a second embodiment of the present invention; [Figure 13] Schematic diagram showing dimensions of each component of a treatment tank according to a second embodiment of the present invention. [Figure 14] 10 is a cross-sectional view of an upper portion of a treatment chamber of a treatment tank according to a third embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0010] The following examples will exemplarily illustrate embodiments of the present disclosure. However, the configurations disclosed in the following examples, such as the functions, materials, shapes, and relative positions of components, are merely examples of embodiments related to the claims, and are not intended to limit the scope of the claims to the configurations disclosed in these examples. Furthermore, the problems solved by the configurations disclosed in the following examples or the actions or effects obtained from the disclosed configurations are not intended to limit the scope of the claims.

[0011] (Embodiment 1) FIG. 1 is a schematic diagram showing the general configuration of a thermal sphering device according to an embodiment of the present invention.

[0012] The thermal sphering device X according to this embodiment is a heat treatment device that performs a heat treatment (sphering process) to spheronize toner particles to a desired circularity in the manufacturing process of toner used as a developer in so-called electrophotographic image forming devices. The circularity of toner particles is known to affect the transferability of toner in the electrophotographic image forming process and the uniformity of the in-plane gloss of the formed image, and therefore, in order to improve image quality, a sphering process is sometimes performed to shape toner particles to a desired circularity.

[0013] <Configuration of the thermal sphering device> As shown in FIG. 1, the thermal sphering device X according to this embodiment includes a treatment tank 1, a hot air supply unit 2, a toner supply unit 3, a cold air supply unit 4, and a toner recovery unit 5. The treatment tank 1 includes a treatment chamber 10 (see FIG. 2, etc.) for subjecting toner particles to a predetermined heat treatment. The hot air supply unit 2 serves as a hot air supplying means and supplies hot air into the treatment chamber 10 of the treatment tank 1. The toner supply unit 3 serves as a toner particle supplying means and supplies toner particles into the treatment chamber of the treatment tank 1. The cold air supply unit 4 serves as a cold air supplying means and supplies cold air into the treatment chamber of the treatment tank 1. The toner recovery unit 5 serves as a toner particle recovery means and recovers heat-treated toner particles from the treatment chamber of the treatment tank 1.

[0014] The specific configuration of each component of the thermal sphering device X according to this embodiment may be similar to that of a conventionally known thermal sphering device, except for the configuration of the treatment tank 1, which will be described later. The specific configurations of the hot air supply unit 2, the toner supply unit 3, the cold air supply unit 4, and the toner recovery unit 5 will not be described here. That is, the specific configuration of each component is not limited to a specific one, and it is sufficient that, like known devices, an airflow is generated within the treatment chamber 10, moving toner particles from the supply port to the recovery port, and forming a heat treatment zone and a cooling zone along the path of the toner particles. Furthermore, the configuration is not limited to a specific one, as long as it is possible to appropriately control the speed of the airflow, the amount of toner particles supplied and recovered, and the temperatures of the heat treatment zone and the cooling zone.

[0015] <Configuration of treatment tank> FIG. 2 is a schematic cross-sectional view of the treatment tank 1 in this embodiment. FIG. 3 is a schematic perspective view of the treatment tank 1 in this embodiment. FIG. 4 is a schematic perspective view of the center pole 16 in this embodiment, where the configuration other than the center pole 16 is not shown in FIG. 3. FIG. 5 is a schematic perspective view of the treatment tank 1 in this embodiment, where the center pole 16 is not shown in FIG. 3. FIG. 6 is a schematic perspective view showing an enlarged view of the tip (around the upper end) of the center pole 16 in this embodiment. FIG. 7 is a schematic horizontal cross-section of various parts of the treatment tank 1 in this embodiment, where (a) is a cross-sectional view taken along the line AA in FIG. 3, (b) is a cross-sectional view taken along the line BB in FIG. 3, (c) is a cross-sectional view taken along the line CC in FIG. 3, and (d) is a cross-sectional view taken along the line DD in FIG. 3.

[0016] As shown in FIGS. 2 and 3, the treatment tank 1 includes a hot air introduction section 12, a toner introduction section 13, a first cold air introduction section 14A, a second cold air introduction section 14B, and a toner discharge section 15. A center pole 16, which is a flow straightening member, is erected in the treatment chamber 10 of the treatment tank 1. The treatment tank 1 has a substantially cylindrical structure with a central axis extending in a vertical direction. The center pole 16 is erected in the center of the treatment chamber 10, i.e., as shown in FIGS. 2 and 3, so that its central axis is coaxial with the central axis of the treatment tank 1. That is, the central axis AX shown in FIGS. 2 and 3 is the central axis of the treatment tank 1 (the inner circumferential surface 102 of the treatment chamber 10) and also the central axis of the center pole 16 (the cone 163).

[0017] The inner wall of the processing tank 1 forming the processing chamber 10 has a configuration in which a top surface 101 and a cylindrical inner peripheral surface (cylindrical surface, side surface) 102 having a central axis AX parallel to the vertical direction are directly connected. 2 and 3, it is preferable that the inner peripheral surface 102 has an inclined surface (tapered surface) 103 connecting the top surface 101 and the inner peripheral surface 102. The inner peripheral surface has a bottom surface 104 on the vertically lower side. The top surface 101 is provided with a hot air supply port 120. The inner peripheral surface 102 is provided with a toner supply port (toner particle supply port) 130, a first cold air supply port 140A, a second cold air supply port 140B, and a toner recovery port 150.

[0018] <Hot air intake section> As shown in FIGS. 2 and 5 , the hot air introduction section 12 forms a hot air supply path 20 that guides the hot air supplied from the hot air supply section 2 into the processing chamber 10. The hot air supply path 20 extends vertically downward from above the processing tank 1 and communicates with the inside of the processing chamber 10 via a hot air supply port 120. The hot air supply port 120 opens in the top surface 101 of the processing chamber 10. The hot air supply port 120 is a circular opening that is concentric with the approximately circular top surface 101 (inner circumferential surface 102). The hot air supplied from the hot air supply section 2 is introduced into the processing chamber 10 by being blown downward from the hot air supply port 120 on the top surface 101 of the processing chamber 10 into the processing chamber 10.

[0019] <Center pole> 2, 3, and 4, the center pole 16 is a columnar member having a substantially cylindrical shape, and is arranged upright in the processing chamber 10 coaxially with the inner circumferential surface 102 of the processing chamber 10 so that its tip faces the hot air supply port 120 in the direction of the central axis AX (vertical direction). The center pole 16 is a flow straightening member that forms an air current that causes the toner particles to move downward within the processing chamber 10 while swirling in a substantially spiral shape.

[0020] 2 and 4, the center pole 16 has an upper end surface 161 and an outer peripheral surface (side surface) 162. The upper end surface 161 of the center pole 16 is lower in height than the ceiling surface 101 of the processing chamber 10 and faces the ceiling surface 101 and the hot air supply port 120 in the vertical direction. The outer peripheral surface 162 of the center pole 16 has a smaller diameter than the inner peripheral surface 102 of the processing chamber 10 and faces the inner peripheral surface 102 at a predetermined radial distance. A cone (convex member) 163 and a louver 164 are provided on the upper end surface 161 of the center pole 16. A refrigerant flow path (not shown) is provided inside the center pole 16.

[0021] <Corn> 2, 4, and 6, the cone 163 is a convex member having a generally conical shape that protrudes upward from the upper end surface 161 of the center pole 16. The cone 163 is disposed on the upper end surface 161 of the center pole 16 so as to be coaxial with and face the hot air supply port 120. The cone 163 is also disposed so that the height of its tip is higher than the top surface 101, and the tip side is recessed into the hot air supply port 120. It is preferable that the tip (apex) of the cone 163 be rounded.

[0022] <Louver> As shown in Figures 2, 4, and 6, the louvers 164 are spirally curved wall portions that protrude upward from the upper end surface 161 of the center pole 16. Multiple louvers 164 are arranged radially to surround the outer periphery of the cone 163. Each of the multiple louvers 164 is curved so that the direction of extension gradually changes to a direction along the circumferential direction about the central axis line as it moves from the outer periphery of the lower end of the cone 163 toward the outer diameter side in the radial direction relative to the central axis line of the center pole 16. The multiple louvers 164 are arranged at equal intervals around the outer periphery of the cone 163.

[0023] 2, the louvers 164 are configured so that their tips come into contact with the top surface 101 of the processing chamber 10. That is, the louvers 164 divide the space between the upper end surface 161 of the center pole 16 and the top surface 101 of the processing chamber 10 into circumferentially separated portions around the outer periphery of the cone 163. This is a straightening section configured to divide the processing tank 1 into a plurality of spiral spaces. For example, the processing tank 1 may be configured such that the top plate that constitutes the top surface 101 of the processing chamber 10 is placed on the louvers 164, and the louvers 164 are sandwiched vertically between the top plate and the upper end surface 161 of the center pole 16. The straightening action of the cones 163 and the louvers 164 will be described in detail later.

[0024] 4, 6, and 7, the treatment tank 1 of this embodiment is configured so that the swirling direction of the airflow flowing inside the treatment chamber 10 is counterclockwise in the circumferential direction around the central axis AX when viewed from above toward below in the direction of the central axis AX. Therefore, the louvers 164 extend in a curved manner that extends counterclockwise as they extend radially outward. The direction in which the louvers 164 extend approaches the radial direction as they are closer to the outer periphery of the cone 163, and approaches the direction along the outer periphery of the upper end surface 161 of the center pole 16 (the outer periphery 162 of the center pole 16) as they are closer to the outer periphery of the upper end surface 161.

[0025] The swirling direction of the airflow may be configured to be clockwise, in which case the curvature direction of the louvers 164, the supply direction of the toner particles, the introduction direction of the cold air, the recovery direction of the heat-treated toner particles, and other configurations are opposite to those of the respective parts of the treatment tank 1 of this embodiment.

[0026] <Toner introduction section> The toner supply unit 3 and the toner introduction unit 13 are configured, for example, to introduce compressed air into the processing chamber 10, and toner particles T are transported and introduced into the processing chamber 10 on the compressed air. As shown in FIGS. 2, 5, and 7(b), the toner introduction unit 13 forms a toner supply path 30 that guides the toner particles supplied from the toner supply unit 3 into the processing chamber 10. The toner supply path 30 extends in a direction inclined both vertically and horizontally on the side of the processing tank 1 and communicates with the processing chamber 10 through a toner supply port 130 that opens on the inner circumferential surface 102 of the processing chamber 10. When viewed in the direction of the central axis AX, the toner supply path 30 extends in a direction tangent to the inner circumferential surface 102. In other words, the horizontal component of the flow direction of the compressed air airflow TF supplied from the toner supply unit 3 is parallel to the tangent direction in a horizontal cross section of the inner circumferential surface 102 of the processing chamber 10, which is a cylindrical surface. Furthermore, when viewed in the radial direction relative to the central axis AX, the toner supply path 30 extends in a direction that gradually decreases in the circumferential direction of the inner circumferential surface 102 as it approaches the toner supply port 130. In other words, the direction of the compressed air flow TF supplied from the toner supply unit 3 is at a downward angle relative to the horizontal.

[0027] The toner supply port 130 is disposed on the upper side of the inner peripheral surface 102 of the processing chamber 10, and opens into the annular space AS between the outer peripheral surface 162 of the center pole 16 and the inner peripheral surface 102 of the processing chamber 10. The edge of the toner supply port 130 has a shape that is approximately diamond-shaped when the inner peripheral surface 102 is developed into a plane.

[0028] 11(a) is a schematic diagram showing the opening shape of the toner supply port 130 when the inner circumferential surface 102 of the processing chamber 10 is developed into a plane. As shown in FIG. 11(a), the edge of the toner supply port 130 is composed of a pair of first edges 1301 extending parallel to each other in the vertical direction and a pair of second edges 1302 extending parallel to each other in a direction inclined with respect to the circumferential direction. That is, the toner supply port 130 has a diamond-shaped opening shape with the pair of first edges 1301 as first opposing sides and the pair of second edges 1302 as second opposing sides. The pair of second edges 1302 are inclined downward at an angle θT (°) with respect to the horizontal.

[0029] The inclination direction of the toner supply path 30 and the toner supply port 130 is such that the toner flows downward spirally through the annular space AS between the outer peripheral surface 162 of the center pole 16 and the inner peripheral surface 102 of the processing chamber 10. That is, the toner supply path 30 and the toner supply port 130 are configured to introduce the toner particles into the processing chamber 10 in a direction that does not oppose the flow of the spiral hot air current formed in the annular space AS by the hot air supply unit 2.

[0030] 7(b) is a cross-sectional view taken along the arrow BB in FIG. 3, and is a schematic cross-sectional view perpendicular to the central axis AX at the position where the toner supply port 130 is provided in the treatment tank 1. When viewed in the direction of the central axis AX, the direction in which the toner supply path 30 guides the toner particles is substantially the same as the direction of the airflow that flows downward while spiraling through the annular space AS.

[0031] In this embodiment, when viewed from above toward below in the direction of the central axis AX, the rectifying action of the louvers 164 creates an airflow that swirls counterclockwise around the central axis AX. The toner supply port 130 has an opening shape that introduces toner particles into the annular space AS along the flow of this counterclockwise swirling airflow. In other words, the direction in which the second edge 1302 of the toner supply port 130 slopes downward is approximately the same as the direction in which the airflow formed in the annular space AS between the inner circumferential surface 102 and the outer circumferential surface of the center pole 16 spirals downward from above to below the annular space AS.

[0032] 3, 5, and 7(b), the treatment tank 1 in this embodiment has four toner introduction sections 13, and four toner supply ports 130 open to the treatment chamber 10. The four toner introduction sections 13 are arranged at equal intervals in the circumferential direction of the inner circumferential surface 102.

[0033] In this embodiment, the toner supply ports 130 are provided in multiple locations, and the toner particles, which are the thermoplastic particles to be treated, are dispersed and introduced from multiple locations, but for example, only one toner supply port 130 may be provided, and the toner particles may be introduced from that single location. When multiple toner supply ports 130 are provided, four or eight ports are preferable.

[0034] <1st cold air introduction section> As shown in FIGS. 2, 5, and 7(c), the first cold air introduction section 14A forms a first cold air supply path 40A that guides cold air supplied from the cold air supply section 4 into the processing chamber 10. The first cold air supply path 40A extends in a direction inclined both vertically and horizontally on the side of the processing tank 1 and communicates with the interior of the processing chamber 10 via a first cold air supply port 140A that opens on the inner circumferential surface 102 of the processing chamber 10. When viewed in the direction of the central axis AX, the first cold air supply path 40A extends in a direction tangent to the inner circumferential surface 102. In other words, the horizontal component of the flow direction of the cold air airflow CF supplied from the cold air supply section 4 is parallel to the tangent direction in a horizontal cross section of the inner circumferential surface 102 of the processing chamber 10. When viewed in the radial direction relative to the central axis AX, the first cold air supply passage 40A extends in a direction that gradually decreases toward the first cold air supply port 140A in the circumferential direction of the inner peripheral surface 102. That is, the direction of the cold air flow CF supplied from the cold air supply unit 4 is at a downward angle relative to the horizontal.

[0035] The first cold air supply port 140A is located below the toner supply port 130 on the inner circumferential surface 102 and opens into the annular space AS. The edge of the first cold air supply port 140A has a shape that is approximately diamond-shaped when the inner circumferential surface 102 is developed into a plane.

[0036] 11(b) is a schematic diagram showing the opening shape of the first cold air supply port 140A when the inner circumferential surface 102 of the processing chamber 10 is developed into a plane. As shown in FIG. 11(b), the edge of the first cold air supply port 140A is composed of a pair of first edges 1401A extending parallel to each other in the vertical direction and a pair of second edges 1402A extending parallel to each other in a direction inclined with respect to the circumferential direction. That is, the first cold air supply port 140A has a diamond-shaped opening shape with the pair of first edges 1401A as first opposing sides and the pair of second edges 1402A as second opposing sides. The pair of second edges 1402A are inclined in a direction having a downward angle θC (°) with respect to the horizontal direction, There are.

[0037] The inclination direction of the first cold air supply path 40A and the first cold air supply port 140A is a direction that is approximately along the direction in which the air current formed within the processing chamber 10 moves downward in a spiral shape within the processing chamber 10. In other words, the first cold air supply path 40A and the first cold air supply port 140A are configured to introduce cold air toward the processing chamber 10 so as to follow the flow of the hot air current within the processing chamber 10 formed by the hot air supply unit 2. When providing multiple first cold air supply ports 140A, four or eight are preferable.

[0038] The processing tank 1 in this embodiment is provided with four first cold air supply ports 140A, and the four first cold air supply ports 140A open to the processing chamber 10. The four first cold air supply ports 140A are arranged at equal intervals in the circumferential direction of the inner circumferential surface 102.

[0039] <Second cold air introduction section> As shown in FIGS. 2, 5, and 7(d), the second cold air introduction section 14B forms a second cold air supply path 40B that guides the cold air supplied from the cold air supply section 4 into the processing chamber 10. The second cold air supply path 40B extends horizontally from the side of the processing tank 1 and communicates with the interior of the processing chamber 10 via a second cold air supply port 140B that opens on the inner circumferential surface 102 of the processing chamber 10. When viewed in the direction of the central axis AX, the second cold air supply path 40B extends in a direction tangent to the inner circumferential surface 102. In other words, the flow direction of the cold air airflow CF supplied from the cold air supply section 4 is parallel to the tangent direction in a horizontal cross section of the inner circumferential surface 102 of the processing chamber 10.

[0040] The second cold air supply port 140B is located lower than the first cold air supply port 140A on the inner circumferential surface 102 and opens into the annular space AS. The edge of the second cold air supply port 140B has a rectangular parallelepiped shape when the inner circumferential surface 102 is developed into a plane. More specifically, the second cold air supply port 140B has a rectangular parallelepiped opening shape made up of a pair of edge portions extending parallel to each other in the vertical direction and a pair of edge portions extending parallel to each other in the circumferential direction.

[0041] The second cold air supply path 40B and the second cold air supply port 140B are configured to introduce cold air into the processing chamber 10 along the circumferential direction around the central axis AX at the bottom surface 104 of the processing chamber 10, along the flow of air within the processing chamber 10.

[0042] The treatment tank 1 in this embodiment is provided with three second cold air supply ports 140B, and the three second cold air supply ports 140B open to the treatment chamber 10. The three second cold air supply ports 140B, together with a toner recovery port 150 (described later), are arranged at equal intervals in the circumferential direction of the inner circumferential surface 102.

[0043] In this embodiment, the second cold air supply port 140B is disposed at a height where it contacts the lower end of the inner circumferential surface 102, and is provided at approximately the same height as the toner recovery port 150. From the viewpoint of smoothly guiding toner particles to the toner recovery port 150, the height at which the second cold air supply port 140B is provided is preferably the same as the toner recovery port 150 as in this embodiment, but it may also be provided at a position higher than the toner recovery port 150. In this case, the second cold air supply path 40B and the second cold air supply port 140B may be configured to be inclined, similar to the first cold air supply path 40A and the first cold air supply port 140A, depending on, for example, the height from the bottom surface 104 of the processing chamber 10.

[0044] In this embodiment, the cold air supply unit 4 is configured to supply cold air in two stages using two cold air introduction sections, the first cold air introduction section 14A and the second cold air introduction section 14B. This configuration is merely an example, and the number of cold air introduction sections may be one or more.

[0045] In this embodiment, the first cold air supply ports 140A and the second cold air supply ports 140B are provided at a plurality of locations. In the present embodiment, the first cold air supply port 140A and the second cold air supply port 140B are provided at two or more locations in the circumferential direction, and cold air is introduced from each of them.

[0046] <Toner discharge section> As shown in FIGS. 2, 5, and 7(d), the toner discharge section 15 forms a toner discharge path 50 for recovering heat-treated toner particles from the treatment chamber 10 to the toner recovery section 5. The toner discharge path 50 extends horizontally from the side of the treatment tank 1 and communicates with the interior of the treatment chamber 10 via a toner recovery port 150 that opens on the inner circumferential surface 102 of the treatment chamber 10. When viewed in the direction of the central axis AX, the toner discharge path 50 extends in a direction tangent to the inner circumferential surface 102. Similar to the second cold air supply port 140B, the edge of the toner recovery port 150 has a rectangular shape when the inner circumferential surface 102 is developed into a plane.

[0047] In this embodiment, only one toner recovery port 150 is provided, and the heat-treated toner particles are recovered at one location, but it is also possible to provide multiple toner recovery ports 150 and recover the toner particles at multiple locations in a dispersed manner.

[0048] <Thermal sphering treatment> As shown in FIG. 2, the space between the outer wall surfaces (top end surface 161, outer peripheral surface 162, outer peripheral surface of cone 163, louvers 164) of center pole 16 and the inner wall surfaces (top surface 101, inner peripheral surface 102, bottom surface 104) of processing chamber 10 forms a heat treatment space where toner particles are heat-treated. The airflow flowing through the heat treatment space of processing chamber 10 is composed of a heat treatment airflow made of hot air and a cooling airflow formed by merging the hot air with cold air. The heat treatment airflow forms a heat treatment zone HZ in an annular space AS between the inner peripheral surface 102 of processing chamber 10 and the outer peripheral surface 162 of center pole 16. The cooling airflow forms a cooling zone CZ below the heat treatment zone HZ in the annular space AS.

[0049] As shown in Figure 6, the hot air HA blown down from the hot air supply port 120 collides with the tip of the cone 163, and flows from the tip of the cone 163 toward its base (lower end) along the conical outer surface of the cone 163, dispersing to form an airflow CDR that spreads out in a generally conical shape. After passing through the base of the cone 163, the hot air HA forms an airflow SHF that flows spirally in the horizontal direction (perpendicular to the central axis AX) toward the outer periphery of the upper end surface 161 of the center pole 16 due to the rectifying action of the louvers 164 arranged around the outer periphery of the cone 163. That is, the hot air HA passes through the rectifying space formed between the multiple louvers 164, which extends in a spiral curve. At this time, the traveling direction of the hot air HA gradually changes from a radial direction to a counterclockwise direction around the central axis AX as it moves toward the outer diameter side in the radial direction relative to the central axis AX.

[0050] The hot air HA, which has been subjected to the rectifying action of the louvers 164 and has reached the outside of the upper end surface 161 of the center pole 16, changes its direction of travel from a counterclockwise direction around the central axis AX to a direction along the central axis AX and enters the annular space AS. In the annular space AS, an airflow SDF (heat treatment airflow) is formed, which descends while swirling in a spiral around the outer circumferential surface 162 of the center pole 16.

[0051] As the heat treatment airflow descends around the outer circumferential surface 162 of the center pole 16, it carries the toner particles introduced together with the compressed air from the toner supply port 130 along with it to the downstream cooling airflow. As the toner particles travel along the heat treatment airflow, they become molten and change their circularity. For example, toner particles that initially have a distorted outer shape gradually become more spherical, and their circularity is deformed to fall within a predetermined range. Furthermore, during this deformation process, shear forces due to the swirling flow act on the toner particles, dispersing the toner supplied to the treatment tank 1. Coalescence of the toner particles is suppressed, and therefore toner having a desired particle size and deformed to a predetermined range of circularity can be obtained.

[0052] The heat treatment zone HZ, in which the toner particles are heat-treated by the heat treatment airflow, extends in the annular space AS from the hot air supply port 120 to the upper end of the first cold air supply port 140A (to the height where the hot air merges with the cold air introduced from the first cold air supply port 140A).

[0053] When the hot air forming the heat treatment airflow merges with the cold air introduced from the first cold air supply port 140A and its temperature drops, the airflow carrying the toner particles switches from the heat treatment airflow to a cooling airflow. A cooling zone CZ, where the toner particles are cooled by the cold air forming this cooling airflow, is formed in the annular space AS from the first cold air supply port 140A to the bottom surface 104 of the processing chamber 10. Like the heat treatment airflow, the cooling airflow descends while spiraling around the outer circumferential surface 162 of the center pole 16. The cooling airflow lowers the temperature of the heat-treated toner particles and stabilizes their shape. When the cooling airflow reaches the lower end of the annular space AS, it is sucked into the toner recovery port 150. The toner particles cooled by the cooling airflow are sucked into the toner recovery port 150 and collected in the toner recovery unit 5.

[0054] <Fusion of toner particles> In a thermal sphering device in which toner particles are subjected to heat treatment by being entrained in an air current from a supply port in the ceiling of the treatment chamber and spirally descending within the chamber, the toner particles may fuse to the wall surface of the treatment chamber or coalesce or coalesce with each other. Such fusion and coalescence of toner particles may affect the productivity of toner particles with a desired circularity and the maintainability of the treatment device.

[0055] The fusion of toner particles to the processing chamber wall is believed to occur when the toner particles contact the processing chamber wall while in a molten state. Furthermore, the coalescence and adhesion of toner particles is believed to occur when the toner particles remain in a molten state for a long time, increasing the chances of contact between the toner particles. The toner particles are molten in the heat treatment zone formed by hot air, and after achieving the desired circularity, they are cooled in the cooling zone formed by cold air and collected through the toner collection port. Here, some toner particles may return from the cooling zone to the heat treatment zone or be unable to escape the heat treatment zone due to the influence of the air currents formed in the processing chamber, particularly the ascending air currents, resulting in a prolonged residence time in the heat treatment zone. Such retention of toner particles in the heat treatment zone increases the chances of contact between the molten toner particles and the processing chamber wall, as well as the chances of contact between molten toner particles themselves.

[0056] Research conducted by the inventors of the present invention has revealed that in a treatment tank configured to heat-treat toner particles by forming a spiral airflow swirling around the center pole from the top to the bottom of the treatment chamber, toner particles are particularly susceptible to fusion in the upper region of the treatment chamber. In this type of treatment tank, toner particles tend to accumulate and fuse around the upper end of the center pole and the upper end of the inner circumferential surface of the treatment chamber, particularly around the upper end of the toner supply port. It has been found that the accumulation of toner particles in the upper region of the treatment chamber is caused by an ascending airflow generated in the annular space of the treatment chamber. This ascending airflow is believed to be formed by the separation of airflow in the annular space of the treatment chamber. Specifically, inside the spiral descending airflow that spirals from top to bottom within the treatment chamber (inner side of the annular space), an ascending airflow is formed that separates from the spiral descending airflow and flows from bottom to top within the treatment chamber along the outer shape of the center pole.

[0057] <Slope> The treatment tank 1 of this embodiment employs a configuration in which, as a configuration for suppressing the fusion of the toner particles, an inclined surface 103 is provided between the top surface 101 and the inner circumferential surface 102, the inclined surface being inclined with respect to both the top surface 101 and the inner circumferential surface 102. Research by the inventors of the present invention has found that the action of the inclined surface 103 suppresses the generation of an updraft in the airflow formed in the annular space AS.

[0058] 8(a) is a schematic cross-sectional view of the region above the processing chamber 10 in the processing tank 1x of Comparative Example 1, which does not have the inclined surface 103. FIG. 8(b) is a schematic cross-sectional view of the region above the processing chamber 10 in the processing tank 1 of Embodiment 1, which has the inclined surface 103.

[0059] 8(a), at the upper end side of the annular space AS, the hot air supplied from the hot air supply port 120 descends along the conical surface of the cone 163 and changes direction to a horizontal spiral circling direction toward the outer diameter side due to the rectifying action of the louvers 164. After that, the hot air passing through the louvers 164 changes direction vertically downward and descends while spiralling in the annular space AS.

[0060] In the comparative treatment tank 1x, toner particles are significantly fused together around the toner supply port 130 on the inner circumferential surface 102 of the treatment chamber 10 and around the outlet of the spiral flow path defined by the louvers 164 of the center pole 16. In other words, these areas are areas in the treatment tank 1x where toner particles are likely to accumulate and fuse together. The accumulation of toner particles in the upper region of the treatment chamber 10 is caused by an updraft UF generated in the annular space AS, which is thought to be formed by the separation of airflow in the annular space AS. Specifically, inside the spiral downdraft SDF, which spirals downward within the treatment chamber 10, an updraft UF is formed that separates from the spiral downdraft SDF and flows upward within the treatment chamber along the outer shape of the center pole.

[0061] The hot air supplied from the hot air supply port 120 bounces off the upper end surface 161 of the center pole 16, generating a vortex in the louvers 164, which may reach the vicinity of the toner supply port 130. The hot air that has generated such a vortex merges with the ascending air current UF generated near the outer circumferential surface 162 of the center pole 16, and entrains the toner introduced from the toner supply port 130 into the ascending air current UF. The toner particles entrained in the ascending air current UF are blown up above the toner supply port 130 and end up accumulating around the toner supply port 130 and around the outlet of the spiral flow path formed by the louvers 164.

[0062] Furthermore, in comparative embodiment 1, the inner peripheral surface 102 of the processing chamber 10 is disposed opposite the straightening flow outlet of the louver 164. As a result, the horizontal spiral airflow SHF of the hot air HA that has passed through the louver 164 continues horizontally and collides with the inner peripheral surface 102 of the processing chamber 10. This collision causes a loss in the flow of the horizontal spiral airflow SHF, and as a result, the flow of the spiral downflow SDF weakens, making it easier for an upflow UF that is separated from the spiral downflow SDF to occur in the annular space AS.

[0063] In the processing tank 1 of embodiment 1, a tapered inclined surface 103 provided between the top surface 101 and the inner peripheral surface 102 of the processing chamber 10 is arranged to face the straightening flow outlet of the louver 164. A vertical downward component is imparted to the horizontal spiral airflow SHF of the hot air HA that passes through the louver 164 and collides with the inclined surface 103, according to the angle of the inclined surface 103. This encourages the flow of the hot air HA from the horizontal spiral airflow SHF to a spiral downflow SDF. This reduces the loss of the airflow due to collision with the inner wall surface of the processing chamber 10, and the flow of the hot air HA is changed direction from the horizontal spiral airflow SHF to the spiral downflow SDF with little loss. As a result, a spiral downflow SDF of sufficient strength is formed in the annular space AS, and the annular space A The generation of an updraft UF at S is suppressed, and the fusion of toner particles is suppressed.

[0064] Here, the inventors of the present invention have found through their research that it is preferable for the inclined surface 103 to be a flat surface whose cross section extends linearly. When the inventors analyzed the airflow within the processing chamber 10, they found that in the processing chamber 10 in which the top surface 101 and the inner peripheral surface 102 are connected at a right angle, as in Comparative Example 1, a ring-shaped ascending airflow occurs at the upper corner of the processing chamber 10. More specifically, the ring-shaped ascending airflow is generated prominently in the corner between the top surface 101 and the inner peripheral surface 102 and near the upper end of the outer peripheral surface 162 of the center pole 16 (near the boundary with the upper end surface 161). Furthermore, the inventors of the present invention have found through their research that the effect of suppressing the ascending airflow described above is not sufficient when, for example, a configuration in which the top surface 101 and the inner peripheral surface 102 are connected by a concave R-shaped curved surface (Comparative Example 2) is used.

[0065] The structural differences between the first embodiment and the first and second comparative embodiments include, for example, the following: In comparative embodiments 1 and 2, the inner wall surface (ceiling surface 101 and inner circumferential surface 102) of the processing chamber 10 facing the corner of the upper edge, which is the boundary between the upper end surface 161 and the outer circumferential surface 162 of the center pole 16, is configured to be recessed in a direction receding from the corner of the center pole 16. In contrast, in the present embodiment, the closest position between the corner of the center pole 16 and the inner wall surface of the processing chamber 10 is configured to be located on the inclined surface 103. From another perspective, this can be said to be a configuration in which the flow path area of ​​the airflow passing through the upper end corner of the center pole 16 is narrowed by the inclined surface 103 in the first embodiment.

[0066] In particular, in the configuration of Comparative Form 1, the portion of the inner wall surface of the processing chamber 10 that is closest to the upper corner of the center pole 16 is the top surface 101 or the inner peripheral surface 102. In other words, the corner portion between the top surface 101 and the inner peripheral surface 102 is recessed in a direction away from the upper corner of the center pole 16, and it can be said that this configuration is prone to causing airflow stagnation (airflow accumulation) in such a recess. Although the configuration of Comparative Form 2 somewhat suppresses the occurrence of airflow accumulation compared to the configuration of Comparative Form 1, it can be said that this configuration is unlikely to achieve a sufficient suppression effect like that of Embodiment 1.

[0067] As described above, according to the configuration of the first embodiment, it is possible to effectively suppress the generation of the ascending air current UF in the annular space AS, and to suppress the fusion and adhesion of toner particles.

[0068] <Dimensional Relationship of Treatment Tank in First Embodiment> FIG. 9 is a schematic diagram showing the dimensions of each component of the treatment tank 1 of the first embodiment. FIG. 10 is a schematic cross-sectional view of the treatment tank 1, illustrating the dimensions of each component of the treatment tank 1. Note that FIG. 10 shows only one representative each of the toner introduction section 13, first cold air introduction section 14A, and second cold air introduction section 14B, of which multiple sections are provided. FIG. 11(a) is a schematic diagram of the toner supply port 130 when the inner circumferential surface 102 of the treatment chamber 10 is developed in a plane. FIG. 11(b) is a schematic diagram of the first cold air supply port 140A when the inner circumferential surface 102 of the treatment chamber 10 is developed in a plane.

[0069] In FIG. 9, A is the outer diameter of the bottom surface of the cone 163. B is the radius of the hot air supply port 120. D is the diameter of the outer surface 162 of the center pole 16, which is the outer diameter of the top surface 161. E is the diameter of the inner surface 102 of the processing chamber 10. F is the height from the top surface 161 of the center pole 16 to the ceiling surface 101 of the processing chamber 10. G is the height of the tip of the cone 163 from the top surface 161 of the center pole 16.

[0070] Table 1 shows the expected ranges of the various dimensions shown in FIG. 9 and their preferred ranges.

[0071] (Table 1) TIFF0007760567000001.tif44170

[0072] In FIG. 10, I is the height from the bottom surface 104 to the top surface 101 of the processing chamber 10. J is the vertical range of the heat treatment zone HZ formed in the processing chamber 10, and is the vertical width from the lowest point at the upper end of the toner supply port 130 to the lowest point at the upper end of the first cold air supply port 140A. K is the vertical range of the cooling zone CZ formed in the processing chamber 10, and is the vertical width from the lowest point at the upper end of the first cold air supply port 140A to the bottom surface 104 of the processing chamber 10. L is the horizontal width of the toner introduction section 13. M is the vertical width of the upstream opening of the toner introduction section 13. N is the horizontal width of the first cold air introduction section 14A. O is the vertical width of the upstream opening of the first cold air introduction section 14A. P is the horizontal width of the second cold air introduction section 14B. Q is the vertical width of the upstream opening of the second cool air introduction portion 14B.

[0073] Table 2 shows the expected ranges of the various dimensions shown in FIG. 10 and their preferred ranges.

[0074] (Table 2) TIFF0007760567000002.tif61170

[0075] Within the above dimensional ranges, the diameter of the circle that is the boundary line between top surface 101 and inclined surface 103 is set to be the same diameter as the diameter of outer circumferential surface 162 of center pole 16. Furthermore, the height of toner supply port 130 is set to be lower than the position of upper end surface 161 of center pole 16. Furthermore, the above dimensions are set so that the width (DA) in the radial direction relative to central axis AX of louver 164 is secured to be in the expected range of 15 mm to 150 mm, and preferably in the range of 28 mm to 111 mm.

[0076] In this embodiment, twelve louvers 164 are arranged around the cone 163 at equal intervals of 30°.

[0077] The basic operating conditions for the sphering process of the thermal sphering device X of this embodiment are, for example, as follows: It is set as follows. Toner particle supply rate (processing rate, feed rate): 5 kg / hr ·Hot air temperature: 160℃ ·Hot air volume: 7.0m 3 / min ·Cold air temperature: -5℃ First stage cold air (introduced in 4 sections): 0.5m 3 / min Second stage cool air (introduced in three sections): 0.5m 3 / min Compressed gas volume: 0.4m 3 / min divided into 4 parts Blower air volume: 15.0m 3 / min

[0078] <Comparative Experiment 1> Here, when the difference between the outer diameter and inner diameter of inclined surface 103 was 60 mm and the angle γ formed by inclined surface 103 with top surface 101 was set to 17°, 27°, and 40°, the reduction rates of the ascending air current component were 1.1%, -3.6%, and -1.1%, respectively. Therefore, a comparative experiment was conducted with respect to the average particle size and average circularity of toner particles between Example 1, in which the angle γ of inclined surface 103 was set to 27°, and Comparative Example 1, which did not have inclined surface 103. In this comparative experiment, the supply rate (processing rate) of toner particles was set to 10.3 kg / hr.

[0079] <Method for measuring weight average particle size (D4)> The weight-average particle size (D4) of the toner is calculated as follows. The measurement device used is a precision particle size distribution measurement device using the narrow-pore electrical resistance method, the Coulter Counter Multisizer 3 (registered trademark, manufactured by Beckman Coulter, Inc.), equipped with a 100 μm aperture tube. The measurement conditions are set and the measurement data is analyzed using the accompanying dedicated software, the Beckman Coulter Multisizer 3 Version 3.51 (manufactured by Beckman Coulter, Inc.). The measurement is performed using an effective number of measurement channels of 25,000.

[0080] The aqueous electrolyte solution used for the measurement is prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of approximately 1% by mass, such as "ISOTON II" (manufactured by Beckman Coulter, Inc.).

[0081] Before performing measurements and analysis, the dedicated software was configured as follows. In the "Change Standard Measurement Method (SOM)" screen of the dedicated software, the total count in control mode was set to 50,000 particles, the number of measurements was set to 1, and the Kd value was set to the value obtained using a "Standard Particle 10.0 μm" (Beckman Coulter, Inc.). The threshold and noise level were automatically set by pressing the "Threshold / Noise Level Measurement Button." The current was set to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and the "Flush aperture tube after measurement" checkbox was checked. In the "Pulse to Particle Size Conversion Settings" screen of the dedicated software, the bin spacing was set to logarithmic particle size, the particle size bins to 256 particle size bins, and the particle size range from 2 μm to 60 μm.

[0082] The specific measurement method is as follows. (1) Pour approximately 200 mL of the electrolyte solution into a 250 mL round-bottom glass beaker made specifically for the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, use the "aperture flush" function of the dedicated software to remove any dirt and air bubbles from inside the aperture tube.

[0083] (2) Approximately 30 mL of the above electrolytic solution is placed in a 100 mL flat-bottom glass beaker. A 10% by weight aqueous solution of "Contaminon N" (a neutral detergent for cleaning precision measuring instruments, pH 7, consisting of a nonionic surfactant, anionic surfactant, and organic builder, manufactured by Wako Pure Chemical Industries) is added as a dispersant. Approximately 0.3 mL of a diluted solution prepared by diluting PEG-1000 (manufactured by PEG-1000 Co., Ltd.) with ion-exchanged water approximately three times by mass is added.

[0084] (3) Prepare an ultrasonic disperser "Ultrasonic Dispension System Tetora150" (manufactured by Nikkaki Bios Co., Ltd.) with an electrical output of 120 W and two built-in oscillators with an oscillation frequency of 50 kHz and a phase difference of 180 degrees. Place approximately 3.3 L of ion-exchanged water in the ultrasonic disperser's water tank and add approximately 2 mL of Contaminon N to this water tank.

[0085] (4) Set the beaker (2) in the beaker fixing hole of the ultrasonic disperser, operate the ultrasonic disperser, and adjust the height of the beaker so that the resonance state of the liquid surface of the electrolytic solution in the beaker is maximized.

[0086] (5) While the electrolyte solution in the beaker in (4) is irradiated with ultrasonic waves, approximately 10 mg of toner is added little by little to the electrolyte solution and dispersed. The ultrasonic dispersion process is then continued for another 60 seconds. During the ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be between 10°C and 40°C.

[0087] (6) Using a pipette, add the electrolyte solution (5) containing the dispersed toner to the round-bottom beaker (1) placed in the sample stand, and adjust the measurement concentration to approximately 5%. Then, measure the particle count until it reaches 50,000 particles.

[0088] (7) The measurement data is analyzed using the dedicated software provided with the device to calculate the weight-average particle size (D4). Note that when the dedicated software is set to Graph / Volume %, the "Average diameter" on the "Analysis / Volume Statistics (Arithmetic Mean)" screen is the weight-average particle size (D4).

[0089] <Method for measuring average circularity> The average circularity of the toner particles is measured using a flow type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) under the measurement and analysis conditions at the time of calibration work.

[0090] The specific measurement method is as follows. First, approximately 20 mL of ion-exchanged water, from which impurities such as solids have been removed, is placed in a glass container. Approximately 0.2 mL of a solution prepared by diluting "Contaminon N" (a 10% by weight aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) approximately three times by weight with ion-exchanged water is added. Approximately 0.02 g of the sample to be measured is then added, and the mixture is dispersed for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. The dispersion is then cooled appropriately so that its temperature is between 10°C and 40°C. A tabletop ultrasonic cleaner / disperser ("VS-150" manufactured by Vervoclear Co., Ltd.) with an oscillation frequency of 50 kHz and an electrical output of 150 W is used as the ultrasonic disperser. A predetermined amount of ion-exchanged water is placed in the water tank, and approximately 2 mL of the Contaminon N is added to the water tank.

[0091] The measurement was performed using the flow particle image analyzer equipped with a standard objective lens (10x magnification), and a particle sheath "PSE-900A" (manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion prepared according to the procedure described above was introduced into the flow particle image analyzer, and 3,000 toner particles were measured in HPF measurement mode and total count mode. The binarization threshold for particle analysis was set to 85%, and the analyzed particle diameter was limited to a circle-equivalent diameter of 1.985 μm or more and less than 39.69 μm, and the average circularity of the toner particles was determined.

[0092] Before starting the measurement, standard latex particles (Duke Scientific's "RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A") were diluted with ion-exchanged water. After that, it is preferable to perform focus adjustment every two hours from the start of measurement.

[0093] In the examples of the present application, a flow-type particle image analyzer was used that had been calibrated by Sysmex Corporation and had a calibration certificate issued by Sysmex Corporation. Measurements were performed under the same measurement and analysis conditions as when the calibration certificate was received, except that the particle diameter to be analyzed was limited to a circle-equivalent diameter of 1.985 μm or more and less than 39.69 μm.

[0094] (Table 3) Relationship between average toner particle size and processing temperature TIFF0007760567000003.tif32153

[0095] (Table 4) Relationship between average circularity of toner particles and processing temperature TIFF0007760567000004.tif24153

[0096] As shown in Tables 3 and 4, in Comparative Example 1, the higher the processing temperature, the greater the changes in the toner average particle size and circularity. In contrast, in Example 1, such changes were suppressed, and as a result, the fusion of toner particles was reduced compared to Comparative Example 1. In other words, according to Example 1, it was possible to suppress variations in the toner average particle size and circularity of toner particles due to differences in processing temperature.

[0097] According to the findings of the inventors of the present invention, assuming the dimensional ranges shown in Figures 10 and 11, the practical setting range for the angle θ (°) that inclined surface 103 makes with respect to top surface 101 in a vertical cross section is 10 < θ ≦ 45°. The lower limit of 10° and the upper limit of 45° are values ​​obtained through research by the inventors of the present invention as limit values ​​within which the effects of inclined surface 103 can be expected. Within this range, the inclination angle of inclined surface 103 is set appropriately in accordance with other device dimensions.

[0098] In this embodiment, the direction of the compressed air flow TF flowing into the processing chamber 10 by the toner supply unit 3 and the toner introduction unit 13 is a direction that forms a downward angle θT (°) with respect to the horizontal direction. In this embodiment, the angle θT is set so that the angle θ (°) that the inclined surface 103 makes with the top surface 101 satisfies θT≦θ.

[0099] <Embodiment 2> A treatment tank 1b according to a second embodiment of the present invention will be described. Here, only the differences between the second embodiment and the first embodiment will be described. Items in the second embodiment that are not specifically described here are the same as those in the first embodiment.

[0100] The treatment tank 1b of embodiment 2 is configured such that, compared to the treatment tank 1 of embodiment 1, the tip (apex) of the cone 163 is given an R-shape with a radius of curvature within a predetermined range, and the upper outer peripheral edge (corner) of the center pole 16 is given an R-shape with a radius of curvature within a predetermined range. The introduction of these predetermined R shapes can also effectively suppress the generation of ascending air current components in the air current within the processing chamber 10. Furthermore, when the processing tank 1b is configured to have an inclined surface 103, a synergistic effect can be achieved, making it possible to more effectively suppress the generation of ascending air current components.

[0101] 12 is a schematic cross-sectional view of the region above the treatment chamber 10 in the treatment tank 1b of the second embodiment. According to the configuration of the treatment tank 1b of the second embodiment, the predetermined rounded shape provided at the tip of the cone 163 allows the hot air HA to smoothly change direction from collision with the tip of the cone 163 to the formation of a conical dispersed airflow CDF along the outer surface of the cone 163. Furthermore, the predetermined rounded shape provided at the outer peripheral edge (corner) of the upper end of the center pole 16 allows the hot air HA passing through the louvers 164 to smoothly change direction from a horizontal spiral airflow SHF to a spiral downdraft SDF. This suppresses the generation of an ascending airflow UF in the annular space AS, suppressing the retention of toner particles above the treatment chamber 10 and suppressing the fusion of toner particles.

[0102] <Dimensional Relationship of Treatment Tank in Second Embodiment> Figure 13 is a schematic diagram showing the dimensions of each component of the treatment tank 1b of embodiment 2. The setting ranges for each dimension A, B, D, E, F, and G in embodiment 2 are the same as those in embodiment 1. In embodiment 2, C is the outer diameter of the upper end surface 161 of the center pole 16, and is the diameter from the central axis AX to the boundary between the upper end surface 161 and the R-shaped portion 165. H is the difference in the vertical direction between the position of the tip of the cone 163 of the center pole 16 and the position of the boundary between the R-shaped portion 165 of the center pole 16 and the outer peripheral surface 162. Table 5 shows the expected dimensional ranges of the various dimensions shown in Figure 13 and their preferred ranges.

[0103] (Table 5) TIFF0007760567000005.tif55170

[0104] <Comparative Experiment 2> Regarding the effect of providing a rounded shape to the tip (apex) of the cone 163, a comparative experiment was conducted between Example 2, in which a rounded shape with a curvature radius of 10 mm was provided to the tip of the cone 163, and Comparative Example 2, in which no rounded shape was provided to the tip of the cone 163. In this comparative experiment, the toner particle supply rate (processing rate) was 8.0 kg / hr, and the hot air flow rate was 8.0 m 3 / min.

[0105] (Table 6) Relationship between average toner particle size and processing temperature TIFF0007760567000006.tif43170

[0106] (Table 7) Relationship between average circularity of toner particles and processing temperature TIFF0007760567000007.tif32170

[0107] As shown in Tables 6 and 7, Example 2 reduced the change in circularity due to changes in processing temperature (stable circularity) and reduced the change in average toner particle size. As a result, the fusion of toner particles was reduced more than in Comparative Example 2.

[0108] According to the findings of the inventors of the present invention, on the premise of the dimensional ranges shown in FIGS. 10, 11, and 13, the practical setting range of the radius of curvature R (mm) of the R shape attached to the tip (vertex) of the cone 163 is 0 < R ≦ 85, and preferably, 5 < R < 45.

[0109] <Comparative Experiment 3> A comparative experiment was conducted on the effect of imparting an R shape to the outer peripheral edge (corner) of the upper end of the center pole 16. In this comparative experiment, Example 3 in which a 7-mm R shape was imparted to the outer peripheral edge of the upper end of the center pole 16, Example 4 in which an 18-mm R shape was imparted to the outer peripheral edge of the upper end of the center pole 16, and Comparative Example 3 in which no R shape was imparted to the outer peripheral edge of the upper end of the center pole 16 were compared. In this comparative experiment, the average circularity of the processed toner particles in each of Example 3, Example 4, and Comparative Example 3 at a processing temperature of 180° C. was measured.

[0110] (Table 8) TIFF0007760567000008.tif27170

[0111] As shown in Table 8, as a result of the experiment, it was found that the circularity improves as the radius of curvature of the R shape imparted to the outer peripheral edge of the upper end of the center pole 16 increases.

[0112] <Comparative Experiment 4> A comparative experiment was conducted on the effect of the combination of the R shape at the tip (vertex) of the cone 163 and the R shape at the outer peripheral edge (corner) of the upper end of the center pole 16 in Embodiment 2 with the inclined surface 103. In this comparative experiment, Comparative Example 4 was configured such that the upper corners of the processing chamber 10 were not provided with inclined surfaces 103, and the upper outer periphery of the center pole 16 was rounded. In Example 2, the angle γ of the inclined surfaces 103 was set to 27°, and the tip of the cone 163 was rounded with a radius of curvature of 10 mm. For both Example 2 and Comparative Example 4, the radius of curvature RCP of the R-shape provided on the upper outer periphery of the center pole 16 was varied to 18, 27, 45, 60, 70, 80, 100, and 120 mm, and the ascending air current component within the processing chamber 10 was obtained by SIM analysis. Then, for both Example 2 and Comparative Example 4, the reduction rate of the ascending air current component at each radius of curvature RCP was obtained compared to Comparative Example 1, in which the processing chamber 10 was not provided with inclined surfaces 103 and the center pole 16 and cone 163 were not rounded. The results are shown in Table 9.

[0113] (Table 9) TIFF0007760567000009.tif25170

[0114] In Comparative Example 4, when R was in the range of 100 mm or more, the effect of suppressing updrafts was similar to that of Example 2, but when R was in the range of less than 45 mm, the effect of suppressing updrafts was extremely reduced, and in the range of 45 mm to 80 mm, the effect varied. In contrast, in Example 2, the effect of suppressing updrafts was able to be obtained over a wider range than in Comparative Example 4.

[0115] According to the knowledge of the inventors of the present invention, assuming the dimensional ranges shown in FIGS. 10, 11, and 13, the practical setting range of the radius of curvature of the R-shape given to the upper outer peripheral edge (corner portion) of the center pole 16 in this embodiment is 5. <RCP<75である。

[0116] <Embodiment 3> A treatment tank 1c according to a third embodiment of the present invention will be described. Here, only the differences between the third embodiment and the first and second embodiments will be described. Items in the third embodiment that are not specifically described here are the same as those in the first and second embodiments.

[0117] In the third embodiment, the ceiling surface of the processing chamber 10 is not a horizontal surface like the ceiling surface 101 in the first and second embodiments, but is a tapered inclined surface 103c. Furthermore, in the third embodiment, the tip (upper end) of the center pole 16c is not provided with a horizontal surface like the upper end surface 161 in the first and second embodiments, but is provided with a conical protrusion 163c that protrudes from the boundary with the outer circumferential surface 162. A louver 164c for forming a spiral swirling flow is provided, for example, on the conical outer circumferential surface of the protrusion 163c. Furthermore, the tip (apex) of the protrusion 163c is given an R-shape, similar to the tip of the cone 163 in the second embodiment.

[0118] When the hot air blown down from the hot air supply port 120 hits the tip of the convex portion 163c, it disperses and descends along the conical outer peripheral surface of the convex portion 163c, and then, due to the rectifying action of the louvers 164c, it spirals and heads vertically downward along the outer peripheral surface of the convex portion 163c. The hot air that has passed through the louvers 164c descends in the annular space AS between the inner peripheral surface 102 of the processing chamber 10 and the outer peripheral surface 162 of the center pole 16, spiraling around the outer peripheral surface 162 of the center pole 16.

[0119] In the first and second embodiments, the inclined surface 103 that slopes downward toward the outer periphery of the processing chamber 10 is partially inclined toward the outer periphery of the hot air supply port 120 when the processing chamber 10 is viewed in the direction of the central axis AX. In contrast, in the third embodiment, when the processing chamber 10 is viewed in the direction of the central axis AX, an inclined surface 103c is present around the entire outer periphery of the hot air supply port 120 in the processing chamber 10. According to the third embodiment, there is no wall between the hot air supply port 120 and the annular space AS that restricts the airflow to a horizontal direction, and the connection is such that the airflow from the hot air supply path 20 to the annular space AS is gentle. Therefore, the generation of an updraft in the annular space AS can be effectively suppressed.

[0120] The above-described embodiments and examples can be combined with each other in any configuration possible.

[0121] The disclosure of the embodiments of the present invention includes the following configurations and methods. (Configuration 1) a treatment tank having a treatment chamber for subjecting the toner particles to a heat treatment; a toner particle supply means for supplying toner particles into the processing chamber; hot air supply means having a supply port for supplying hot air into the inside of the processing chamber; In a heat treatment apparatus comprising: a supply port of the hot air supply means is disposed on the ceiling of the processing chamber; The treatment tank comprises: a columnar member provided vertically in the center of the interior of the processing chamber; a convex member having a substantially conical shape provided at an upper end of the columnar member and protruding toward the ceiling; and The columnar member has a cylindrical shape, and in a vertical cross section, the radius of curvature RCP (mm) of the upper edge is: 5 <RCP<75 A heat treatment apparatus characterized by: (Configuration 2) the treatment tank has a top surface and a side surface on which the supply port opens, 2. The heat treatment apparatus according to claim 1, wherein the convex member is provided so as to face the supply port in a vertical direction. (Configuration 3) the treatment tank has a top surface and a side surface on which the supply port opens, a toner particle supply port for supplying the toner particles supplied from the toner particle supply means into the processing chamber is provided on the side surface; 2. The heat treatment device according to claim 1, wherein the height of the toner particle supply port on the side surface is lower than the position of the upper edge of the columnar member. (Configuration 4) the treatment tank has a top surface and a side surface on which the supply port opens, a cold air supply port for supplying cold air from a cold air supply means into the processing chamber is provided on the side surface below the toner particle supply port; 2. The heat treatment device according to claim 1, wherein the treatment tank includes a recovery means for recovering toner particles below the cold air supply port. (Configuration 5) The radius of curvature R (mm) of the tip of the convex member is 5 <R<45 5. The heat treatment apparatus according to any one of configurations 1 to 4, wherein: (Configuration 6) a treatment tank having a treatment chamber for subjecting the toner particles to a heat treatment; a toner particle supply means for supplying toner particles into the processing chamber; hot air supply means having a supply port for supplying hot air into the inside of the processing chamber; In a heat treatment apparatus comprising: a supply port of the hot air supply means is disposed on the ceiling of the processing chamber; A heat treatment apparatus characterized in that an inclined surface that slopes downward toward the outer periphery of the treatment chamber is present on the outer periphery of the supply port of the hot air supply means. (Configuration 7) The treatment tank has a top surface and a side surface, 7. The heat treatment apparatus according to configuration 6, wherein the inclined surface connects the top surface and the side surface and is inclined with respect to the top surface and the side surface. (Configuration 8) The inclined surface has an angle θ (°) with respect to the top surface in a vertical cross section, 10<θ≦45 8. The heat treatment apparatus according to configuration 7, wherein: (Configuration 9) 9. The heat treatment apparatus according to any one of configurations 6 to 8, wherein the inclined surface is a surface that extends linearly in a vertical cross section. (Configuration 10) 9. The heat treatment apparatus according to configuration 7 or 8, wherein the height of the boundary between the inclined surface and the side surface is lower than the position of the supply port of the hot air supply means. (Configuration 11) 11. The heat treatment device according to any one of configurations 6 to 10, wherein the side surface is provided with a toner particle supply port for supplying the toner particles supplied from the toner particle supply means into the treatment chamber. (Configuration 12) the toner particle supplying means supplies toner particles into the processing chamber by causing an airflow toward the processing chamber, the side surface of the processing chamber is a cylindrical surface, 12. The heat treatment device according to claim 11, wherein a horizontal component of the direction of the airflow supplied from the toner particle supply means is parallel to a tangential direction in a horizontal cross section of the cylindrical surface. (Configuration 13) The direction of the airflow supplied from the toner particle supply means has a downward angle θT (°) with respect to the horizontal direction, and the angle θ (°) that the inclined surface makes with respect to the ceiling surface of the processing chamber is: θT≦θ 13. The heat treatment apparatus according to claim 12, wherein the direction satisfies the above. (Configuration 14) The treatment tank has a top surface and a side surface, a cold air supply port for supplying cold air from a cold air supply means into the processing chamber is provided on the side surface below the toner particle supply port; 7. The heat treatment device according to claim 6, wherein the treatment tank includes a recovery means for recovering toner particles below the cold air supply port. (Configuration 15) The treatment tank comprises: a columnar member provided vertically in the center of the interior of the processing chamber; a convex member having a substantially conical shape provided at an upper end of the columnar member and protruding toward the top surface; and The columnar member has a cylindrical shape, 8. The heat treatment apparatus according to configuration 7, wherein the diameter of the circle that is the boundary between the top surface and the inclined surface is the same as the diameter of the columnar member. (Method 1) A method for producing a toner by subjecting toner particles to a heat treatment using a heat treatment device, comprising: The heat treatment device is a treatment tank having a treatment chamber for subjecting the toner particles to a heat treatment; a toner particle supply means for supplying toner particles into the processing chamber; hot air supply means having a supply port for supplying hot air into the inside of the processing chamber; Equipped with a supply port of the hot air supply means is disposed on the ceiling of the processing chamber; The treatment tank comprises: a columnar member provided vertically in the center of the interior of the processing chamber; a convex member having a substantially conical shape provided at an upper end of the columnar member and protruding toward the ceiling; and The columnar member has a cylindrical shape, and in a vertical cross section, the radius of curvature RCP (mm) of the upper edge is: 5 <RCP<75 A method for producing a toner, comprising: (Method 2) A method for producing a toner by subjecting toner particles to a heat treatment using a heat treatment device, comprising: The heat treatment device is a treatment tank having a treatment chamber for subjecting the toner particles to a heat treatment; a toner particle supply means for supplying toner particles into the processing chamber; hot air supply means having a supply port for supplying hot air into the inside of the processing chamber; Equipped with a supply port of the hot air supply means is disposed on the ceiling of the processing chamber; a surface that slopes downward toward the outer periphery of the processing chamber, the surface being inclined downward toward the outer periphery of the processing chamber; [Explanation of symbols]

[0122] X...thermal sphering device, 1...treatment tank, 10...treatment chamber, 101...ceiling surface, 102...side surface, 103...inclined surface, 120...hot air supply port, 2...hot air supply section, 3...toner supply section, 4...cold air supply section, 5...toner recovery section

Claims

1. a treatment tank having a treatment chamber for subjecting the toner particles to a heat treatment; a toner particle supply means for supplying toner particles into the processing chamber; hot air supply means having a supply port for supplying hot air into the inside of the processing chamber; In a heat treatment apparatus comprising: a supply port of the hot air supply means is disposed on the ceiling of the processing chamber; The treatment tank comprises: a columnar member provided vertically in the center of the interior of the processing chamber; a convex member having a substantially conical shape provided at an upper end of the columnar member and protruding toward the ceiling; and The columnar member has a cylindrical shape, and in a vertical cross section, the radius of curvature RCP (mm) of the upper edge is: 5<RCP<75 and The radius of curvature R (mm) of the tip of the convex member is 5<R<45 A heat treatment apparatus characterized by:

2. the treatment tank has a top surface and a side surface on which the supply port opens, The heat treatment apparatus according to claim 1 , wherein the convex member is provided so as to face the supply port in a vertical direction.

3. the treatment tank has a top surface and a side surface on which the supply port opens, a toner particle supply port for supplying the toner particles supplied from the toner particle supply means into the processing chamber is provided on the side surface; 2. The heat treatment device according to claim 1, wherein the height of the toner particle supply port on the side surface is lower than the position of the upper edge of the columnar member.

4. the treatment tank has a top surface and a side surface on which the supply port opens, a cold air supply port for supplying cold air from a cold air supply means into the processing chamber is provided on the side surface below the toner particle supply port; 2. The heat treatment apparatus according to claim 1, wherein the treatment tank includes a recovery means for recovering toner particles below the cold air supply port.

5. a treatment tank having a treatment chamber for subjecting the toner particles to a heat treatment; a toner particle supply means for supplying toner particles into the processing chamber; hot air supply means having a supply port for supplying hot air into the inside of the processing chamber; In a heat treatment apparatus comprising: a supply port of the hot air supply means is disposed on the ceiling of the processing chamber; an inclined surface that slopes downward toward the outer periphery of the processing chamber is present on the outer periphery of the supply port of the hot air supply means; The treatment tank has a top surface and a side surface, the inclined surface connects the top surface and the side surface and is inclined with respect to each of the top surface and the side surface, a toner particle supply port for supplying the toner particles supplied from the toner particle supply means into the processing chamber is provided on the side surface; the toner particle supplying means supplies toner particles into the processing chamber by causing an airflow toward the processing chamber, the side surface of the processing chamber is a cylindrical surface, a horizontal component of the direction of the airflow supplied from the toner particle supply means is a direction parallel to a tangential direction of a horizontal cross section of the cylindrical surface; The direction of the airflow supplied from the toner particle supply means has a downward angle θT (°) with respect to the horizontal direction, and the angle θ (°) that the inclined surface makes with respect to the ceiling surface of the processing chamber is: θT≦θ A heat treatment apparatus characterized in that the direction satisfies the above.

6. The inclined surface has an angle θ (°) with respect to the top surface in a vertical cross section: 10<θ≦45 6. The heat treatment apparatus according to claim 5, wherein:

7. 7. The heat treatment apparatus according to claim 5, wherein the inclined surface has a shape that extends linearly in a vertical cross section.

8. 7. The heat treatment apparatus according to claim 5, wherein the height of the boundary between the inclined surface and the side surface is lower than the position of the supply port of the hot air supplying means.

9. A cold air supply port is provided on the side surface below the toner particle supply port, for supplying cold air from a cold air supply means into the processing chamber, 6. The heat treatment apparatus according to claim 5, wherein the treatment tank includes a recovery means for recovering toner particles below the cold air supply port.

10. The treatment tank comprises: a columnar member provided vertically in the center of the interior of the processing chamber; a convex member having a substantially conical shape provided at an upper end of the columnar member and protruding toward the top surface; and The columnar member has a cylindrical shape, The diameter of the circle that is the boundary between the top surface and the inclined surface is the same as the diameter of the columnar member. The heat treatment apparatus according to claim 5 .

11. A treatment tank having a treatment chamber for subjecting toner particles to a heat treatment; a toner particle supply means for supplying toner particles into the processing chamber; hot air supply means having a supply port for supplying hot air into the inside of the processing chamber; In a heat treatment apparatus comprising: a supply port of the hot air supply means is disposed on the ceiling of the processing chamber; an inclined surface that slopes downward toward the outer periphery of the processing chamber is present on the outer periphery of the supply port of the hot air supply means; The treatment tank has a top surface and a side surface, the inclined surface connects the top surface and the side surface and is inclined with respect to each of the top surface and the side surface, The treatment tank comprises: a columnar member provided vertically in the center of the interior of the processing chamber; a convex member having a substantially conical shape provided at an upper end of the columnar member and protruding toward the top surface; and The columnar member has a cylindrical shape, 10. The heat treatment apparatus according to claim 9, wherein the diameter of a circle that is a boundary line between the top surface and the inclined surface is the same as the diameter of the columnar member.

12. A method for producing a toner by subjecting toner particles to a heat treatment using a heat treatment device, comprising: The heat treatment device is a treatment tank having a treatment chamber for subjecting the toner particles to a heat treatment; a toner particle supply means for supplying toner particles into the processing chamber; hot air supply means having a supply port for supplying hot air into the inside of the processing chamber; Equipped with a supply port of the hot air supply means is disposed on the ceiling of the processing chamber; The treatment tank comprises: a columnar member provided vertically in the center of the interior of the processing chamber; a convex member having a substantially conical shape provided at an upper end of the columnar member and protruding toward the ceiling; and The columnar member has a cylindrical shape, and in a vertical cross section, the radius of curvature RCP (mm) of the upper edge is: 5<RCP<75 and The radius of curvature R (mm) of the tip of the convex member is 5<R<45 A method for producing a toner, comprising:

13. A method for producing a toner by subjecting toner particles to a heat treatment using a heat treatment device, comprising: The heat treatment device is a treatment tank having a treatment chamber for subjecting the toner particles to a heat treatment; a toner particle supply means for supplying toner particles into the processing chamber; hot air supply means having a supply port for supplying hot air into the inside of the processing chamber; Equipped with a supply port of the hot air supply means is disposed on the ceiling of the processing chamber; an inclined surface that slopes downward toward the outer periphery of the processing chamber is present on the outer periphery of the supply port of the hot air supply means; The treatment tank has a top surface and a side surface, the inclined surface connects the top surface and the side surface and is inclined with respect to each of the top surface and the side surface, a toner particle supply port for supplying the toner particles supplied from the toner particle supply means into the processing chamber is provided on the side surface; the toner particle supplying means supplies toner particles into the processing chamber by causing an airflow toward the processing chamber, the side surface of the processing chamber is a cylindrical surface, a horizontal component of the direction of the airflow supplied from the toner particle supply means is a direction parallel to a tangential direction of a horizontal cross section of the cylindrical surface; The direction of the airflow supplied from the toner particle supply means has a downward angle θT (°) with respect to the horizontal direction, and the angle θ (°) that the inclined surface makes with respect to the ceiling surface of the processing chamber is: θT≦θ 4. A toner manufacturing method according to claim 1, wherein the above formula (1) is satisfied.

14. A method for producing toner by subjecting toner particles to a heat treatment using a heat treatment device, comprising: The heat treatment device is a treatment tank having a treatment chamber for subjecting the toner particles to a heat treatment; a toner particle supply means for supplying toner particles into the processing chamber; hot air supply means having a supply port for supplying hot air into the inside of the processing chamber; Equipped with a supply port of the hot air supply means is disposed on the ceiling of the processing chamber; an inclined surface that slopes downward toward the outer periphery of the processing chamber is present on the outer periphery of the supply port of the hot air supply means; The treatment tank has a top surface and a side surface, the inclined surface connects the top surface and the side surface and is inclined with respect to each of the top surface and the side surface, The treatment tank comprises: a columnar member provided vertically in the center of the interior of the processing chamber; a convex member having a substantially conical shape provided at an upper end of the columnar member and protruding toward the top surface; and The columnar member has a cylindrical shape, The toner manufacturing method according to claim 1, wherein the diameter of the circle that is the boundary between the top surface and the inclined surface is the same as the diameter of the columnar member.

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