JP5022801B2 - Toner manufacturing method, toner, two-component developer, developing device, and image forming apparatus - Google Patents

Description

  The present invention relates to a toner manufacturing method, a toner, a two-component developer, a developing device, and an image forming apparatus.

  Conventionally, for the purpose of improving the characteristics of powder particles such as toner particles, a surface modification treatment for coating the surface of the powder particles with a coating material has been performed.

  As a method for surface modification treatment of powder particles such as toner particles, the powder particles are caused to flow in a powder flow path by applying mechanical stirring force with a rotary stirring means such as a screw, blade, or rotor. There is known a method of spraying a coating material from a spray nozzle onto powder particles in a state. Further, in such a surface modification treatment method, a method has been proposed in which a liquid material is sprayed from a spray nozzle and a coating material contained in the liquid material is coated on the surface of the powder particles (see, for example, Patent Document 1). .

  In the method disclosed in Patent Document 1, powder particles are caused to flow by rotating a rotary stirring means at a peripheral speed of 5 to 160 m / s, and a liquid material is sprayed from the spray nozzle onto the powder particles in a fluid state. Thus, the fine particles contained in the liquid or the coating material film constituting the liquid can be fixedly formed on the surface of the powder. According to the method disclosed in Patent Document 1, the adhesion between the coating material and the powder particles can be improved, and the time required for the surface modification treatment can be shortened.

  However, the method disclosed in Patent Document 1 has the following problems. When powder particles are made to flow by applying mechanical stirring force with a rotary stirring means, and a liquid material containing a coating material is sprayed from the spray nozzle to the powder particles in a fluidized state, the coating material is uniform to the powder particles. In order to obtain coated particles coated with powder, it is necessary to make the powder particles flow in an isolated manner. Although it is necessary to increase the peripheral speed of the rotary stirring means to some extent in order to cause the powder particles to flow in an isolated manner, increasing the peripheral speed of the rotary stirring means increases the flow rate of the powder particles. The frequency with which the particles collide with the inner wall of the device increases. If the frequency with which the powder particles collide with the inner wall of the device increases too much, the powder particles will easily adhere to the inner wall of the device, and other powder particles and coating materials will aggregate and grow with the adhered powder particles as the core. The problem occurs. When the powder particles and the coating material coagulate and grow on the inner wall of the apparatus, there arises a problem that the flow path for the powder particles to flow becomes narrow and hinders the isolated flow, and a problem of yield reduction.

  Therefore, there is a demand for a powder processing method capable of preventing the powder particles from adhering to the inner wall of the apparatus while maintaining the state in which the powder particles are isolated and flowed.

Japanese Patent Laid-Open No. 62-262737

  An object of the present invention is to prevent toner base particles from adhering to the inner wall of the apparatus while maintaining the state where the toner base particles are isolated and flowed, and to improve the coating uniformity of the coating material on the toner base particles. And a toner, a two-component developer, a developing device, and an image forming apparatus.

The present invention relates to a toner in a fluidized state in which toner base particles consisting only of a binder resin, a colorant, a release agent and a charge control agent are caused to flow in a powder flow path by rotation of a rotary stirring means including a rotation shaft. the mother particles, the coating material seen including, by spraying the liquid material viscosity is less than 50cP at 25 ° C. from the spray means, the method for producing a toner for coating a coating material to the toner mother particles,
The peripheral speed at the outermost periphery of the rotary stirring means is 70 m / s or more and 120 m / s or less,
The toner manufacturing method is characterized in that at least a part of the inner wall of the powder flow path is provided with an adhesion preventing portion for preventing the toner base particles from adhering to the inner wall of the powder flow path.

  The toner manufacturing method of the present invention is characterized in that the adhesion preventing portion includes a fluororesin.

  The toner production method of the present invention is characterized in that the spraying means sprays the liquid material at a rate of 20 g or less per minute.

In the toner production method of the present invention, the powder flow path is provided so that the toner base particles flow in a constant powder flow direction,
The angle formed between the liquid spray direction from the spraying means and the powder flow direction is 45 ° or less.

  The toner production method of the present invention is characterized in that the liquid spray direction from the spraying means is perpendicular to the rotation axis of the rotating stirring means.

  The toner production method of the present invention is characterized in that the liquid spray direction from the spraying means is parallel to the rotation axis of the rotating stirring means.

In addition, the present invention is a toner obtained by the toner manufacturing method.
The present invention also provides a two-component developer comprising the above toner and a carrier.

According to another aspect of the present invention, there is provided a developing device which performs development using the above two-component developer.
According to another aspect of the present invention, there is provided an image forming apparatus comprising the above developing device.

According to the present invention, the toner base particles consisting only of the binder resin, the colorant, the release agent and the charge control agent are caused to flow in the flow state by the rotation of the rotary stirring means including the rotation shaft in the powder flow path. to a toner base particles, the coating material seen including, by spraying the liquid material viscosity is less than 50cP at 25 ° C. from the spray means, the method for producing a toner for coating a coating material to the toner base particles, the rotary stirring means The peripheral speed at the outermost periphery is set to 70 m / s or more and 120 m / s or less. Further, an adhesion preventing portion for preventing adhesion of the toner mother particles to the inner wall of the powder channel is provided on at least a part of the inner wall of the powder channel. The outermost periphery of the rotary stirring means is a portion of the rotary stirring means having the longest distance from the rotation axis in the direction perpendicular to the rotation axis of the rotary stirring means. By setting the peripheral speed at the outermost periphery of the rotary stirring means to be not less than 70 m / s and not more than 120 m / s, the toner base particles are allowed to flow in isolation, and the collision frequency of the toner base particles against the inner wall of the flow path is reduced. Can be achieved at the same time.
In addition, since the viscosity of the liquid is 50 cP (25 ° C.) or less, fine spraying is possible without coarsening the spray droplet diameter by the spraying means. This makes it possible to spray a liquid material having a uniform droplet diameter. Further, when the toner base particles collide with the liquid droplets, it is possible to further promote the miniaturization of the liquid droplets. As a result, toner mother particles having excellent uniformity in the coating amount of the coating material can be obtained.

  Further, by providing an adhesion preventing portion on at least a part of the inner wall of the powder flow channel, it is possible to prevent toner mother particles from adhering to the inner wall of the flow channel. Toner base particles, particularly toner base particles made of synthetic resin, etc. usually collide with the inner wall of the powder flow path many times. During the collision, a part of the collision energy is converted into thermal energy and accumulated in the toner base particles. As the number of collisions increases, the thermal energy accumulated in the toner base particles increases, and eventually the toner base particles soften and adhere to the inner wall of the powder flow path. However, if an adhesion preventing portion is provided on at least a part of the inner wall of the powder flow path, the adhesion force of the toner base particles to the inner wall of the powder flow path until coating is completed is reduced, and the adhesion of the toner base particles is ensured. To be prevented. As a result, the toner mother particles and the liquid can be prevented from agglomerating and growing using the adhered toner mother particles as a core, and the flow path for the toner mother particles to flow due to the aggregation of the toner mother particles and the liquid. Can be prevented from becoming narrow. In addition, it is possible to improve the coating uniformity of the coating material on the toner base particles, and to improve the yield of the toner base particles coated with the coating material.

  Further, according to the present invention, since the adhesion preventing part includes the fluororesin having excellent release performance, it is possible to more reliably prevent the toner mother particles from adhering to the adhesion preventing part.

  According to the invention, the spraying means sprays the liquid material at a rate of 20 g or less per minute. When the spraying speed of the liquid material by the spraying means is in such a range, the drying speed of the solvent that is included in the liquid material together with the coating material and disperses or dissolves the coating material can be made sufficiently higher than the spraying speed. Therefore, it is possible to prevent the toner base particles in which the undried solvent remains from adhering to other toner base particles, and to prevent aggregation of the toner base particles.

  According to the present invention, the powder flow path is provided so that the toner base particles flow in a constant powder flow direction, and the angle formed between the liquid spray direction from the spray means and the powder flow direction is 45 ° or less. When the liquid spray direction from the spraying means is set in this way, the liquid droplets are prevented from recoiling at the inner wall of the powder flow path, and the yield of the toner base particles coated with the coating material is reduced. This can be further improved.

  Further, according to the present invention, since the liquid material spraying direction from the spraying means is perpendicular to the rotation axis of the rotary stirring means, the liquid material is sprayed uniformly on the toner base particles flowing by the rotation of the rotary stirring means. The coating uniformity of the coating material onto the toner base particles can be further improved.

  According to the present invention, since the spray direction of the liquid material from the spraying means is parallel to the rotation axis of the rotating stirring means, the liquid material can be sprayed uniformly onto the toner base particles flowing by the rotation of the rotating stirring means. And the coating uniformity of the coating material onto the toner base particles can be further improved.

Further, according to the present invention, the toner of the present invention is obtained by the toner production method.
The coating amount of the coating material is uniform, and toner characteristics such as charging characteristics between individual toner particles are uniform. Therefore, when an image is formed using such a toner, a high-definition image with good image quality without uneven density can be obtained.

  Further, according to the present invention, since the two-component developer contains the above toner and carrier, toner characteristics such as charging characteristics between individual toner particles are uniform. A high-quality image can be obtained.

  Further, according to the present invention, the developing device performs development using the above-described two-component developer, so that a good toner image with high definition and no density unevenness can be formed on the photoreceptor.

  In addition, according to the present invention, since the image forming apparatus includes the above-described developing device, it is possible to obtain a high-definition and good-quality image without uneven density.

  FIG. 1 is a cross-sectional view showing a configuration of a toner manufacturing apparatus 1 according to an embodiment of the present invention. The toner manufacturing apparatus 1 includes a powder flow path 2, a spraying means 3, a rotary stirring means 4, an adhesion preventing part 5, a powder charging part 6, and a powder recovery part 7. . The following description also includes a description of the toner manufacturing method of the present invention. In the toner manufacturing method of the present invention, the toner base particles are caused to flow in the powder flow path 2 by the rotation of the rotary stirring means 4, and the liquid material containing the coating material is sprayed from the spray means 3 to the toner base particles in the fluidized state. This is a method of spraying to coat the toner base particles with a coating material, wherein the peripheral speed at the outermost periphery 4a of the rotary stirring means 4 is 70 m / s or more and 120 m / s or less, and at least one of the inner walls of the powder flow path 2. The part is provided with an adhesion preventing part 5 for preventing toner mother particles from adhering to the inner wall of the powder flow path 2.

  The powder flow path 2 includes a stirring unit 8 and a powder flow unit 9. The stirring unit 8 is a substantially cylindrical container-like member having an internal space. Openings 10 and 11 are formed in the stirring unit 8. The opening 10 is formed so as to penetrate the side wall including the surface 8a of the stirring unit 8 in the thickness direction at a substantially central portion of the surface 8a on one side in the axial direction of the stirring unit 8. Moreover, the opening part 11 is formed in the side surface 8b perpendicular | vertical to the surface 8a of the said axial direction one side of the stirring part 8 so that the side wall containing the side surface 8b of the stirring part 8 may penetrate the thickness direction. The powder flow part 9 has one end connected to the opening 10 and the other end connected to the opening 11. As a result, the internal space of the stirring section 8 and the internal space of the powder flow section 9 are communicated to form the powder flow path 2. The toner base particles and gas flow through the powder flow path 2. A powder input part 6 and a powder recovery part 7 are connected to the powder flow part 9 of the powder flow path 2.

  FIG. 2 is a front view showing a configuration around the powder input unit 6 and the powder recovery unit 7. The powder input unit 6 includes a hopper (not shown) that supplies toner mother particles, a supply pipe 12 that communicates the hopper and the powder flow path 2, and an electromagnetic valve 13 that is provided in the supply pipe 12. The toner base particles supplied from the hopper are supplied to the powder flow path 2 through the supply pipe 12 in a state where the flow path in the supply pipe 12 is opened by the electromagnetic valve 13. The toner base particles supplied to the powder flow path 2 flow in a certain powder flow direction, that is, the direction of the arrow 14 in FIG. When the flow path in the supply pipe 12 is closed by the electromagnetic valve 13, the toner base particles are not supplied to the powder flow path 2. The powder recovery unit 7 includes a recovery tank 15, a recovery pipe 16 that connects the recovery tank 15 and the powder flow path 2, and an electromagnetic valve 17 provided in the recovery pipe 16. In a state where the flow path in the collection pipe 16 is opened by the electromagnetic valve 17, the toner base particles flowing through the powder flow path 2 are collected in the collection tank 15 through the collection pipe 16. Further, in the state where the flow path in the collection pipe 16 is closed by the electromagnetic valve 17, the toner base particles flowing through the powder flow path 2 are not collected.

  The rotating stirring means 4 includes a rotating shaft member 18, a disk-shaped rotating disk 19, and a plurality of stirring blades 20. The rotating shaft member 18 has an axis line that coincides with the axis line of the stirring unit 8 and is formed in the surface 8c on the other side in the axial direction of the stirring unit 8 so as to penetrate the side wall including the surface 8c in the thickness direction. 21 is a cylindrical rod-shaped member that is provided so as to be inserted through 21 and that rotates around an axis by a motor (not shown). The rotary disk 19 is a disk-like member that is supported by the rotary shaft member 18 so that its axis line coincides with the axis line of the rotary shaft member 18 and rotates as the rotary shaft member 18 rotates. The plurality of stirring blades 20 are supported by the turntable 19 and rotate as the turntable 19 rotates.

  The rotational speed of the rotary stirring means 4 is set such that the peripheral speed at the outermost periphery is 70 m / s or more and 120 m / s or less. The outermost periphery of the rotary stirring means 4 is the portion 4a of the rotary stirring means 4 having the longest distance from the axis of the rotary shaft member 18 in the direction perpendicular to the direction in which the rotary shaft member 18 of the rotary stirring means 4 extends. When the peripheral speed at the outermost periphery is not less than 70 m / s and not more than 120 m / s, it is possible to simultaneously achieve the toner mother particles to be isolated and to reduce the collision frequency of the toner mother particles against the inner wall of the flow path. . When the peripheral speed at the outermost periphery is less than 70 m / s, the toner base particles cannot be isolatedly flowed. When the peripheral speed at the outermost periphery exceeds 120 m / s, the frequency of collision of the toner base particles with the inner wall of the flow path increases, and the toner base particles easily adhere to the inner wall of the flow path.

  The spraying means 3 is provided at the bent portion closest to the opening 11 in the flow direction of the toner base particles in the powder flow portion 9 of the spray flow path 2. The spraying means 3 mixes a liquid material storing part for storing a liquid material containing a coating material, a carrier gas storing part for storing a carrier gas, and the liquid material and the carrier gas, and the resulting mixture is mixed in the spray channel 2. And a two-fluid nozzle for spraying liquid droplets onto the toner base particles. Compressed air or the like can be used as the carrier gas.

  In the present embodiment, the two-fluid nozzle of the spray means 3 is inserted into an opening formed in the outer wall of the powder channel 2, and the powder flow direction, which is the direction in which the toner mother particles flow in the powder channel 2. On the other hand, it is slightly inclined toward the inside of the powder flow path 2. Accordingly, the liquid spray direction from the spray means 3 is slightly inclined with respect to the powder flow direction. The liquid spray direction is the direction of the axis of the two-fluid nozzle. The angle θ formed between the liquid spray direction from the spray means 3 and the powder flow direction is preferably 0 ° or more and 45 ° or less. When θ is in such a range, the liquid droplets are prevented from recoiling at the inner wall of the powder flow path 2, and the yield of the toner base particles coated with the coating material can be further improved. it can. When the angle θ formed between the liquid spray direction from the spray means 3 and the powder flow direction exceeds 45 °, the liquid droplets are likely to recoil on the inner wall of the powder flow path 2 and the coating material is coated. The yield of the toner base particles is deteriorated.

  The spray spreading angle φ by the two-fluid nozzle is preferably 20 ° or more and 90 ° or less. If the spread angle φ is out of this range, it may be difficult to uniformly spray the liquid on the toner base particles.

  The spraying speed of the liquid material by the spraying means 3 is preferably 20 g or less per minute. When the spraying speed of the liquid material by the spraying means 3 is within such a range, the drying speed of the solvent that is included in the liquid material together with the coating material and disperses or dissolves the coating material can be made sufficiently higher than the spraying speed. Therefore, it is possible to prevent the toner base particles in which the undried solvent remains from adhering to other toner base particles, and to prevent aggregation of the toner base particles. The spray rate of the liquid material by the spray means 3 is more preferably 0.1 g or more and 20 g or less per minute. When the spraying speed is within such a range, aggregation of toner base particles can be prevented without reducing productivity.

The viscosity of the liquid sprayed by the spraying means 3 is preferably 50 cP (0.050 N · s / m ² ) or less. The viscosity of the liquid is measured at 25 ° C. The viscosity of the liquid can be measured, for example, with a cone plate rotary viscometer.

  When the viscosity of the liquid is 50 cP or less, fine spraying is possible without coarsening the spray droplet diameter by the spraying means 3. This makes it possible to spray a liquid material having a uniform droplet diameter. Further, when the toner base particles collide with the liquid droplets, it is possible to further promote the miniaturization of the liquid droplets. As a result, toner mother particles having excellent uniformity in the coating amount of the coating material can be obtained.

  The adhesion preventing unit 5 is provided on at least a part of the inner wall of the powder flow path 2. The adhesion preventing unit 5 prevents toner mother particles from adhering to the inner wall of the powder flow path 2. The adhesion preventing portion 5 is preferably provided in a portion of the inner wall of the powder flow channel 2 where the toner mother particles are likely to adhere.

  In the present embodiment, the adhesion preventing unit 5 is formed on the inner wall 22 on the downstream side of the spraying means 3 with respect to the powder flow direction in the powder channel 2 and the surface 8a on the one axial side of the stirring unit 8. Provided on the inner wall 23 around the opening 10. The inner wall 22 is in a state where most of the solvent in the liquid sprayed from the spraying means 3 remains without being dried, and when the toner base particles come into contact with the inner wall of the powder channel 2, the powder channel 2. The toner base particles are likely to adhere to the inner wall. In addition, toner mother particles tend to aggregate. On the inner wall 23 in the vicinity of the opening 10, toner mother particles that flow through the powder flow-through portion 9 and flow into the stirring portion 8 from the opening 10 and toner that flows in the stirring portion 8 by stirring by the rotary stirring means 4. Easy to collide with mother particles. As a result, the colliding toner base particles are likely to adhere to the vicinity of the opening 10. Therefore, by providing the adhesion preventing portion 5 at such a portion, it is possible to more reliably prevent the toner mother particles from adhering to the inner wall of the powder flow path 2.

  The adhesion preventing unit 5 is a wall member capable of temperature control. This suppresses the temperature rise and prevents toner mother particles from adhering. Furthermore, the effect can be further enhanced by coating a resin having an adhesion preventing effect as a wall covering material. The adhesion preventing unit 5 includes, for example, a fluorine resin, a silicone resin, and the like, and may further include a synthetic resin other than the above. Among these, it is preferable to be comprised from a fluororesin. When the adhesion preventing portion 5 is made of a fluororesin, a higher adhesion reduction effect can be obtained. As the fluororesin, known ones can be used. For example, homopolymers such as tetrafluoroethylene, trifluoroethylene, vinylidene fluoride, copolymers of tetrafluoroethylene and hexafluoropropylene, tetrafluoroethylene and Examples thereof include a copolymer with perfluoroalkoxyethylene.

  When the adhesion prevention part 5 is comprised from the wall surface member which can control temperature, the method etc. which circulate the medium from a cooling device or a heating apparatus inside a wall surface member, etc. are mentioned.

  When the coating material of the adhesion preventing unit 5 is made of a fluororesin, the adhesion preventing unit 5 is provided by coating the inner wall of the powder flow channel 2 with a fluororesin by a known coating method. As a coating method of the fluororesin, for example, a thin plate-shaped fluororesin molding member is attached to the inner wall of the powder flow path 2 with a double-sided tape or the like, or the fluororesin is dissolved in an appropriate solvent and applied to the inner walls 22 and 23. And a method in which a thermoplastic fluororesin in a molten state is directly applied to the inner wall of the powder flow path 2.

  The coating thickness of the adhesion preventing portion 5 is not particularly limited as long as smooth flow of the toner base particles is not prevented in the powder flow path 2. For example, when the area perpendicular to the powder flow direction of the region where the toner base particles can flow in the powder channel 2 is uniform in any cross section, the adhesion preventing portion coated on the inner wall of the powder channel 2 The thickness of is preferably 0.5 mm or more and 5 mm or less. In the present embodiment, a polytetrafluoroethylene (PTFE) sheet having a thickness of 2 mm is attached as the adhesion preventing portion 5.

  Toner production by the toner production apparatus 1 is performed as follows. First, toner mother particles are supplied to the powder flow path 2 from the powder charging unit 6 in a state where the rotary shaft member 18 of the rotary stirring unit 4 rotates. The peripheral speed of the outermost periphery of the rotary stirring means 4 is set to 70 m / s or more and 120 m / s or less. The toner base particles supplied to the powder flow path 2 are stirred by the rotary stirring means 4 and flow through the powder flow section 9 of the powder flow path 2 in the direction of the arrow 14. When the flow rate of the toner base particles in the powder flow path 2 is stabilized, spraying of the liquid material from the spray means 3 is started. The toner base particles are sprayed with a liquid material from the spraying means 3 while flowing through the powder flow portion 9 of the powder flow path 2, and the surface of the toner base particles is coated with the liquid material. Further, when the thermal energy by stirring is applied, the solvent in the liquid is evaporated and dried. As a result, the coating material contained in the liquid or the coating material previously deposited on the toner base particles is formed into a film and coated on the toner base particles. When the coating amount of the coating material on the toner base particles reaches a desired amount, the spraying of the liquid material from the spraying unit is terminated, the rotation of the rotary stirring unit 4 is stopped, and the toner is collected from the powder collecting unit 7.

  According to the toner manufacturing method of the present invention using such a toner manufacturing apparatus 1, the peripheral speed at the outermost periphery of the rotary stirring means 4 is preferably 70 m / s or more and 120 m / s or less. It is possible to achieve both the isolated flow and the reduction in the collision frequency of the toner base particles with respect to the inner wall of the flow path at the same time. In addition, since the adhesion preventing portion 5 is provided, even if the toner mother particles collide with the inner wall of the powder flow channel 2, the toner mother particles adhere to the inner wall of the powder flow channel 2 in the portion where the adhesion preventing portion 5 is provided. Is prevented. As a result, it is possible to suppress the aggregation and growth of other toner base particles and liquid using the adhered toner base particles as nuclei, and to prevent the flow path for the toner base particles from flowing from becoming narrow. Further, the yield of the toner base particles coated with the coating material can be improved.

  The toner manufacturing apparatus 1 is not limited to the above configuration, and various modifications can be made. For example, in the present embodiment, the adhesion preventing portion 5 is configured to be provided only on a part of the powder channel 2, but is not limited thereto, and is provided on the entire inner wall of the powder channel 2. Also good. When the adhesion preventing portion 5 is provided on the entire inner wall of the powder flow path 2, it is possible to more reliably prevent toner mother particles from adhering to the inner wall of the powder flow path 2. Further, the portion where the adhesion preventing portion 5 is provided may be a bent portion of the powder flow path 2 where the toner mother particles are likely to collide with the flow path 2.

  Such a toner production apparatus can also be obtained by combining a commercially available stirring apparatus and spraying means. As a commercially available stirring apparatus provided with a powder channel and a rotating stirring means, for example, a hybridization system (both trade names, manufactured by Nara Machinery Co., Ltd.) and the like can be mentioned. By mounting the liquid spray unit in such a stirring device, this stirring device can be used as a toner manufacturing apparatus used in the toner manufacturing method of the present invention.

  FIG. 3 is a diagram showing a configuration of a toner manufacturing apparatus 31 according to another embodiment of the present invention. FIG. 3A (a) is a front sectional view of the toner manufacturing apparatus 31 when the toner is manufactured. FIG. 3A (b) is a front sectional view of the toner manufacturing apparatus 31 at the time of powder supply or powder recovery. FIG. 3B (c) is a top cross-sectional view of the toner manufacturing apparatus 31. The toner manufacturing apparatus 31 includes a processing container 32 that forms a powder flow path, a spraying means 33, and a rotary stirring means 34.

  The processing container 32 is a substantially spherical container having a rotary stirring means 34 therein, and includes a hemispherical container body 35 and a hemispherical lid 36. The lid body 36 is detachably provided from the container main body 35, and the processing container 32 is in a closed state shown in FIG. 3A (a) or an open state shown in FIG. 3A (b). In the closed state shown in FIG. 3A (a), the liquid is sprayed onto the toner base particles. In the open state shown in FIG. 3A (b), supply of the toner base particles before coating to the processing container 32 or recovery of the coated toner base particles from the processing container 32 is performed. In the present embodiment, the entire inner wall of the processing container 32 is coated with a fluororesin, and an adhesion preventing portion 37 is provided.

  The rotary stirring means 34 is provided at the bottom of the processing container 32. The rotary stirring means 34 includes a rotor 38 that is rotated by a motor (not shown), and a plurality of (two in this embodiment) stirring blades 39 that are provided so as to extend in the horizontal direction from the vertical side surface of the rotor 38. In the present embodiment, the rotary stirring means 34 is provided so that the rotation shaft 34a coincides with the vertical direction. The rotational speed of the rotary stirring means 34 is set such that the peripheral speed at the outermost periphery is 70 m / s or more and 120 m / s or less, as in the case of the rotary stirring means 4 described above. The outermost periphery of the rotating stirring means 34 is the stirring blade 39 on the opposite side of the rotating shaft 34a that is the longest distance from the rotating shaft 34a in the direction perpendicular to the rotating shaft 34a of the rotating stirring means 34 (that is, the horizontal direction). It is the edge part 39a.

  In the present embodiment, the spray means 33 is provided at a position higher than the upper end of the stirring blade 39 on the side wall of the processing container 32. Above the stirring blade 39, there are a large number of toner mother particles stirred by the stirring blade 39. Therefore, by providing the spraying means 33 at a position higher than the upper end of the stirring blade 39 on the side wall of the processing container 32, the liquid material can be sprayed onto the region where the density of the toner base particles is high, and the coating material can be coated more efficiently. .

  Since the spraying means 33 has the same configuration as the spraying means 3 described above, description thereof is omitted. The spraying means 33 has a liquid spraying direction perpendicular to the rotation axis 34 a of the rotary stirring means 34. When the liquid spraying direction is perpendicular to the rotation axis 34a of the rotary stirring means 34, the liquid can be uniformly sprayed on the toner base particles flowing by the rotation of the rotary stirring means 34. A uniform amount of toner base particles can be obtained.

  Production of toner by the toner production apparatus 31 is performed as follows. First, the processing container 32 is opened to supply toner base particles into the processing container 32. When the toner base particles are supplied, the processing container 32 is closed, and the rotary stirring means 34 is rotated. At this time, the peripheral speed of the outermost periphery of the rotary stirring means 34 is set to 70 m / s or more and 120 m / s or less. The toner base particles stirred by the rotary stirring means 34 flow in the direction of the arrow 35 in the processing container 32. When the flow state of the toner base particles is stabilized, spraying of the liquid material from the spray means 33 is started. The toner base particles are sprayed with a liquid in a state of flowing in the processing container 32 so that the surface of the toner base particles is coated with the liquid. Further, when the thermal energy by stirring is applied, the solvent in the liquid is evaporated and dried. Thus, the coating material contained in the liquid is coated on the toner base particles. When the coating amount of the coating material on the toner base particles reaches a desired amount, the spraying of the liquid material from the spraying means is terminated, the rotation of the rotary stirring means 34 is stopped, the processing container 32 is opened, and the toner is collected.

  According to the toner manufacturing method of the present invention using such a toner manufacturing apparatus 31, since the adhesion preventing portion 37 is provided on the entire inner wall of the processing container 32, the toner base particles collide with the inner wall of the processing container 32. Also, the toner base particles are prevented from adhering. As a result, it is possible to suppress the aggregation and growth of other toner base particles and liquid using the attached toner base particles as nuclei, and the yield of the toner base particles coated with the coating material can be improved.

  In the present embodiment, the adhesion preventing portion 37 is provided on the entire inner wall of the processing container 32, but is not limited to this configuration, and may be provided on a part of the inner wall of the processing container 32. When the adhesion preventing part 37 is provided on a part of the inner wall of the processing container 32, the adhesion preventing part 37 is provided at a part where the toner mother particles collide frequently, for example, a part below the spraying means 33 on the inner wall of the processing container 32. It is preferable.

  FIG. 4 is a front sectional view showing a configuration of a toner manufacturing apparatus 41 according to another embodiment of the present invention. The toner manufacturing apparatus 41 has the same configuration as the toner manufacturing apparatus 31 shown in FIG. 3 except that the position where the spray means 42 is provided is different. In FIG. 4, parts having the same configuration as the toner manufacturing apparatus 31 in FIG. 3 are denoted by the same reference numerals. Also, the description of the parts with the same reference numerals is omitted.

  In the present embodiment, the spray means 42 is provided on the upper portion of the processing container 32. Further, the spraying means 42 has a liquid material spraying direction parallel to the rotation axis 34 a of the rotary stirring means 34. When the liquid spray direction is parallel to the rotating shaft 34a of the rotary stirring means 34, the liquid can be uniformly sprayed on the toner base particles flowing by the rotation of the rotary stirring means 34, and the coating amount of the coating material can be reduced. Uniform toner base particles can be obtained.

  The toner manufacturing method by the toner manufacturing apparatus 41 is the same as the toner manufacturing method by the toner manufacturing apparatus 31 shown in FIG. Also by the toner manufacturing method using such a toner manufacturing apparatus 41, the toner base particles can be isolatedly flowed so that the coating amount of the coating material can be made uniform among the particles, and the inner wall of the processing container 32 can be coated with the toner base. Particles can be prevented from adhering.

  The toner manufacturing apparatus shown in FIGS. 3 and 4 can also be obtained by combining a commercially available stirring apparatus and spraying means. Examples of commercially available stirring devices include a Q-type mixer (manufactured by Hosokawa Micron Corporation). By mounting the liquid spray unit in such a stirring device, this stirring device can be used as a toner manufacturing apparatus used in the toner manufacturing method of the present invention.

  The toner production method of the present invention includes, for example, prevention of solidification of toner base particles, prevention of discoloration, prevention of alteration, improvement of dispersibility, improvement of fluidity, improvement of catalytic effect, control of digestion and absorption, improvement of magnetic properties, It can be used to coat toner base particles for the purpose of improving color tone, improving light resistance, and saving useful substances. The toner base particles coated by such a toner production method include, for example, carriers, electrostatic latent image developing materials such as toner, electromagnetic wave absorbing materials and electromagnetic wave shielding materials, brake shoes and polishing materials, and lubricating materials. , Materials for magnetic separation, materials for magnets, materials for ion exchange resins, immobilized enzyme carriers, display materials for displays, materials for vibration control, materials for paints, coloring materials for rubber and plastics, filling materials, reinforcing materials and paints, Used for coloring materials for paints and adhesives, matte materials, etc.

  As an embodiment of the toner manufacturing method of the present invention, a toner manufacturing method used for an electrostatic latent image developing material will be described below. In the toner production method of the present invention, a mother particle production step for producing toner mother particles, a liquid material preparation step for preparing a liquid material containing a coating material, and a spraying step for spraying the liquid material with the aforementioned toner production apparatus. Including.

[Mother particle production process]
In the mother particle production step, toner mother particles to be coated with the coating material are produced. The toner base particles are particles containing a binder resin and a colorant, and the production method thereof is not particularly limited and can be obtained by a known method. Examples of the method for producing the toner base particles include a dry method such as a pulverization method, a wet polymerization method such as a suspension polymerization method, an emulsion aggregation method, a dispersion polymerization method, a dissolution suspension method, and a melt emulsification method. Hereinafter, a method for producing toner base particles by a pulverization method will be described.

  The binder resin is not particularly limited, and a known binder resin for black toner or color toner can be used. Examples thereof include styrene resins such as polystyrene and styrene-acrylic acid ester copolymer resins, acrylic resins such as polymethyl methacrylate, polyolefin resins such as polyethylene, polyesters, polyurethanes, and epoxy resins. Moreover, you may use resin obtained by mixing a raw material monomer mixture with a mold release agent and performing a polymerization reaction. Binder resin can be used individually by 1 type, or can use 2 or more types together.

  Polyester is excellent in transparency, and can impart good powder fluidity, low-temperature fixability, secondary color reproducibility, and the like to the aggregated particles, and is therefore suitable as a binder resin for color toners. Known polyesters can be used, and examples thereof include polycondensates of polybasic acids and polyhydric alcohols. As the polybasic acid, those known as polyester monomers can be used, for example, terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid and other aromatic carboxylic acids, maleic anhydride Examples thereof include aliphatic carboxylic acids such as acid, fumaric acid, succinic acid, alkenyl succinic anhydride, and adipic acid, and methyl esterified products of these polybasic acids. A polybasic acid can be used individually by 1 type, or can use 2 or more types together. As the polyhydric alcohol, those known as monomers for polyesters can be used. For example, aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, hexanediol, neopentylglycol, glycerin, cyclohexanediol, cyclohexanediene, etc. Examples thereof include aromatic diols such as alicyclic polyhydric alcohols such as methanol and hydrogenated bisphenol A, ethylene oxide adducts of bisphenol A, and propylene oxide adducts of bisphenol A. A polyhydric alcohol can be used individually by 1 type, or can use 2 or more types together. The polycondensation reaction between the polybasic acid and the polyhydric alcohol can be carried out according to a conventional method. For example, the polybasic acid and the polyhydric alcohol are contacted in the presence or absence of an organic solvent and in the presence of a polycondensation catalyst. The process is terminated when the acid value, softening point, etc. of the polyester to be produced reach a predetermined value. Thereby, polyester is obtained. When a methyl esterified product of a polybasic acid is used as a part of the polybasic acid, a demethanol polycondensation reaction is performed. In this polycondensation reaction, for example, the carboxyl group content at the end of the polyester can be adjusted by appropriately changing the mixing ratio of polybasic acid and polyhydric alcohol, the reaction rate, etc., and thus the properties of the resulting polyester are modified. it can. When trimellitic anhydride is used as the polybasic acid, a modified polyester can also be obtained by easily introducing a carboxyl group into the main chain of the polyester. A self-dispersible polyester in water in which a hydrophilic group such as a carboxyl group or a sulfonic acid group is bonded to the main chain and / or side chain of the polyester can also be used. Further, polyester and acrylic resin may be grafted.

  The binder resin preferably has a glass transition point of 30 ° C. or higher and 80 ° C. or lower. If the glass transition point of the binder resin is less than 30 ° C., blocking in which the toner thermally aggregates easily occurs in the image forming apparatus, and storage stability may be lowered. When the glass transition point of the binder resin exceeds 80 ° C., the fixability of the toner to the recording medium is lowered, and there is a possibility that fixing failure occurs.

  As the colorant, organic dyes, organic pigments, inorganic dyes, inorganic pigments and the like commonly used in the electrophotographic field can be used.

  Examples of the black colorant include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, magnetic ferrite, and magnetite.

  Examples of yellow colorants include chrome lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa yellow G, Hansa yellow 10G, benzidine yellow G, and benzidine. Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 138, and the like.

  Examples of the orange colorant include red chrome yellow, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK, C.I. I. Pigment orange 31, C.I. I. And CI Pigment Orange 43.

  Examples of red colorants include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, risor red, pyrazolone red, watching red, calcium salt, lake red C, lake red D, and brilliant carmine 6B. Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B, C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of purple colorants include manganese purple, fast violet B, and methyl violet lake.

  Examples of blue colorants include bitumen, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated products, first sky blue, induslen blue BC, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. And CI Pigment Blue 60.

  Examples of the green colorant include chrome green, chromium oxide, pigment green B, micalite green lake, final yellow green G, C.I. I. And CI Pigment Green 7.

  Examples of the white colorant include compounds such as zinc white, titanium oxide, antimony white, and zinc sulfide.

  One colorant can be used alone, or two or more different colorants can be used in combination. Moreover, even if it is the same color, 2 or more types can be used together. The amount of the colorant used is not particularly limited, but is preferably 5 to 20 parts by weight, more preferably 5 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

  The toner base particles may contain a charge control agent. As the charge control agent, those for positive charge control and negative charge control commonly used in this field can be used. Examples of charge control agents for positive charge control include nigrosine dyes, basic dyes, quaternary ammonium salts, quaternary phosphonium salts, aminopyrines, pyrimidine compounds, polynuclear polyamino compounds, aminosilanes, nigrosine dyes and derivatives thereof, triphenylmethane Derivatives, guanidine salts, amidine salts and the like can be mentioned. Charge control agents for controlling negative charges include oil-soluble dyes such as oil black and spiron black, metal-containing azo compounds, azo complex dyes, metal salts of naphthenic acid, metal salts of salicylic acid and its derivatives (metals are metal Chromium, zinc, zirconium, etc.), boron compounds, fatty acid soaps, long-chain alkyl carboxylates, resin acid soaps, and the like. A charge control agent can be used individually by 1 type, or can use 2 or more types together as needed. The amount of the charge control agent used is not particularly limited and can be appropriately selected from a wide range, but is preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the binder resin.

  The toner base particles may contain a release agent. As the release agent, those commonly used in this field can be used, for example, petroleum wax such as paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax (polyethylene wax, polypropylene Wax etc.) and derivatives thereof, low molecular weight polypropylin wax and derivatives thereof, hydrocarbon polymer waxes such as polyolefin polymer wax (low molecular weight polyethylene wax etc.) and derivatives thereof, carnauba wax and derivatives thereof, rice wax and derivatives thereof , Candelilla wax and its derivatives, plant wax such as wood wax, animal wax such as beeswax and whale wax, fatty acid amide, phenol fatty acid ester, etc. Oil-based synthetic waxes, long-chain carboxylic acids and their derivatives, long-chain alcohols and derivatives thereof, silicone polymers, such as higher fatty acids. Derivatives include oxides, block copolymers of vinyl monomers and waxes, graft modified products of vinyl monomers and waxes, and the like. The amount of the wax used is not particularly limited and can be appropriately selected from a wide range, but is preferably 0.2 to 20 parts by weight, more preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the binder resin. Particularly preferred is 1.0 to 8.0 parts by weight.

  In the mother particle preparation step using a pulverization method, a toner composition containing a binder resin, a colorant, and other additives is dry-mixed with a mixer and then melt-kneaded with a kneader. The kneaded material obtained by melt kneading is cooled and solidified, and the solidified material is pulverized by a pulverizer. Thereafter, particle size adjustment such as classification is performed as necessary to obtain toner mother particles.

  Known mixers can be used, such as Henschel mixer (trade name, manufactured by Mitsui Mining Co., Ltd.), super mixer (trade name, manufactured by Kawata Co., Ltd.), Mechano Mill (trade name, manufactured by Okada Seiko Co., Ltd.), etc. Henschel type mixing apparatus, ongmill (trade name, manufactured by Hosokawa Micron Corporation), hybridization system (trade name, manufactured by Nara Machinery Co., Ltd.), Cosmo system (trade name, manufactured by Kawasaki Heavy Industries, Ltd.), and the like.

  A well-known thing can be used also as a kneading machine, for example, common kneading machines, such as a twin-screw extruder, a 3 roll, a laboratory blast mill, can be used. More specifically, for example, TEM-100B (trade name, manufactured by Toshiba Machine Co., Ltd.), PCM-65 / 87, PCM-30 (all of which are trade names, manufactured by Ikegai Co., Ltd.), etc. Extruder, Needex (trade name, manufactured by Mitsui Mining Co., Ltd.) and other open roll type kneaders. Among these, an open roll type kneader is preferable.

  The colorant may be used as a master batch in order to uniformly disperse the additive for synthetic resin in the kneaded product. Two or more additives for synthetic resin may be used as composite particles. The composite particles can be produced, for example, by adding an appropriate amount of water, lower alcohol or the like to two or more additives for synthetic resin, granulating with a general granulator such as a high speed mill, and drying. The masterbatch and composite particles are mixed into the toner composition during dry mixing.

  The resulting toner base particles preferably have a volume average particle size of 4 μm or more and 8 μm or less. When the volume average particle diameter of the toner base particles is 4 μm or more and 8 μm or less, a high-definition image can be stably formed over a long period of time. Further, by reducing the particle size to this range, a high image density can be obtained even with a small amount of adhesion, and the toner consumption can be reduced. If the volume average particle size of the toner base particles is less than 4 μm, the particle size of the toner base particles becomes too small, and there is a possibility that high charge and low fluidity may occur. When this high charging and low fluidization occur, it becomes impossible to stably supply the toner to the photoreceptor, and there is a possibility that background fogging and a decrease in image density may occur. If the volume average particle size of the toner base particles exceeds 8 μm, it is desirable because the toner base particle size is large, the layer thickness of the formed image is high, and an image with a remarkably graininess is obtained, and a high-definition image cannot be obtained. Absent. Further, as the toner base particle size increases, the specific surface area decreases and the toner charge amount decreases. When the charge amount of the toner is small, the toner is not stably supplied to the photoconductor, and there is a possibility that in-machine contamination due to toner scattering occurs.

[Liquid preparation step]
In the liquid preparation step, a liquid containing the coating material is prepared. As the coating material, for example, a resin, inorganic fine particles, or the like can be used. By using a resin as the coating material, for example, it is possible to prevent the occurrence of aggregation due to melting of low melting point components such as a release agent contained in the toner base particles during storage. Moreover, the spacer effect can be maintained over a long period of time by using inorganic fine particles as the coating material. The spacer effect is an improvement in developability, transferability and cleaning properties by reducing the adhesion between toners, the adhesion between toner and carrier, and the adhesion between toner and various members. For example, the toner performance is maintained by suppressing the burying of the toner.

  As the resin used as the coating material, for example, polyester, acrylic resin, styrene resin, styrene-acrylic copolymer, or the like can be used. The fine resin particles preferably include an acrylic resin, a styrene-acrylic copolymer, or a polyester among the resins exemplified above. Acrylic resin, styrene-acrylic copolymer or polyester has many advantages such as light weight, high strength, high transparency, and low cost.

  The resin used as the coating material may be the same type as the binder resin of the toner base particles, or may be a different type of resin, but a different type of resin in terms of surface modification of the toner. Is preferably used. When a different type of resin is used as the coating material, it is preferable to use a resin whose softening point of the resin used as the coating material is higher than the softening point of the binder resin of the toner base particles. As a result, the toner is prevented from fusing with each other during storage, and storage stability can be improved. The softening point of the resin used as the coating material is preferably 80 ° C. or higher and 140 ° C. or lower, although it depends on the image forming apparatus in which the toner is used. By using a resin having such a temperature range, a toner having both storage stability and fixing ability can be obtained.

  The resin used as the coating material is preferably fine resin particles. By using the fine resin particles as the resin, for example, when the liquid is sprayed on the toner base particles with a liquid in which the fine resin particles are dispersed and coated, the shape of the fine resin particles remains on the surface of the toner base particles and is smooth. As compared with a toner having a surface, a toner having excellent cleaning properties can be obtained. Such fine resin particles can be obtained, for example, by emulsifying and dispersing fine resin particle raw materials with a homogenizer or the like to make fine particles. It can also be obtained by monomer polymerization.

  The volume average particle size of the fine resin particles needs to be sufficiently smaller than the average particle size of the toner base particles, and the volume average particle size of the fine resin particles is preferably 0.05 μm or more and 1 μm or less. . The volume average particle size of the fine resin particles is more preferably 0.1 μm or more and 0.5 μm or less. When the volume average particle diameter of the fine resin particles is 0.05 μm or more and 1 μm or less, a protrusion having a suitable size is formed on the surface of the coating layer. As a result, the toner is easily caught on the cleaning blade during cleaning, and the cleaning performance is improved.

  A conventionally well-known thing can be used as an inorganic particle. As inorganic particles, for example, inorganic fine powders such as silicon dioxide, titanium oxide, aluminum oxide, cerium oxide, zinc oxide, tin oxide, zirconium oxide, polystyrene, acrylic resin, styrene-acrylic resin, polyester, polyolefin, cellulose, Examples include resin fine powders such as polyurethane, benzoguanamine, melamine resin, nylon, silicone resin, phenol resin, and vinylidene fluoride. The inorganic fine powder may be surface treated with a hydrophobizing agent such as silicone oil, silane coupling agent, hexamethyldisilazane (HMDS). Among these, silicon dioxide and titanium oxide, which are excellent in terms of fluidity improvement, triboelectric chargeability improvement, heat resistance, long-term storage stability improvement, cleaning property improvement and photoreceptor surface wear property control, are particularly preferable. More preferably, the surface of silicon dioxide and titanium oxide is subjected to a hydrophobic treatment.

  The inorganic particles preferably have a primary particle number average particle size of 40 nm to 300 nm. The spacer effect can be maintained over a long period of time by externally adding such inorganic particles having a large particle diameter and preventing separation of the inorganic particles. The spacer effect is an improvement in developability, transferability and cleaning properties by reducing the adhesion between toners, the adhesion between toner and carrier, and the adhesion between toner and various members. For example, the toner performance is maintained by suppressing the burying of the toner. If the number average particle size of the primary particles is less than 40 nm, the spacer effect may not be exhibited. If the number average particle size of the primary particles exceeds 300 nm, the fluidity of the toner may not be improved.

  The solvent for dispersing or dissolving the coating material is not particularly limited, but it is preferably a liquid that easily evaporates because it needs to be removed after spraying the liquid. The solvent for dispersing or dissolving the coating material preferably contains a lower alcohol. Examples of the lower alcohol include methanol, ethanol, propanol and the like. When the solvent contains such a lower alcohol, the particulate coating material can be dispersed in the solvent, the wettability of the particulate coating material to the toner base particles can be improved, and the entire surface of the toner base particles Or it becomes easy to adhere particulate coating material to most. In addition, the drying time when removing the solvent can be further shortened, and aggregation of the toner base particles can be suppressed.

  Further, the solvent for dispersing or dissolving the coating material is not limited to those exemplified above, for example, water, butanol, octanol, decyl alcohol, diethylene glycol, glycerin, polyethylene glycol, phenol, benzyl alcohol, methylbenzyl alcohol, etc. Alcohols, acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone and other ketones, methyl ethyl ether, diethyl ether, methyl butyl ether, methyl isobutyl ether, dimethyl ether, diisopropyl ether, octyl phenyl ether and other ethers, Methyl acetate, ethyl acetate, ethyl oleate, ethyl acrylate, methyl methacrylate, dibutyl succinate, diethyl phthalate Diethyl tartrate, ethyl palmitate, and may be esters such as dioctyl phthalate.

  The liquid is prepared, for example, by adding a coating material to the solvent exemplified above and dissolving or dispersing the coating material in the solvent using a stirrer, an ultrasonic homogenizer, or the like.

  The liquid material preferably contains 5 parts by weight or more and 30 parts by weight or less of the coating material with respect to 100 parts by weight of the solvent for dissolving or dispersing the coating material. When the solvent and the coating material are contained in such a ratio, the viscosity of the liquid material is suitable, and the spraying of the liquid material by the spraying means is easy. Further, since the ratio between the solvent and the coating material is suitable, the softened state of the surface of the toner base particles by the spraying of the liquid can be suitably maintained. If the ratio of the coating material to 100 parts by weight of the solvent for dissolving or dispersing the coating material is less than 5 parts by weight, the ratio of the solvent in the liquid may be too large, and the toner base particle surface may be too soft. In addition, the ratio of the solvent in the liquid becomes too large, and the time for removing the solvent becomes too long. If the ratio of the coating material with respect to 100 parts by weight of the solvent in the liquid exceeds 30 parts by weight, the liquid may have a high viscosity and the spraying means 3 may become clogged, which may make it difficult to spray the liquid. is there.

[Spraying process]
In the spraying process, for example, the toner production apparatus 1 of FIG. 1 is used, and the liquid material containing the coating material is sprayed by the spraying means 3 to coat the toner base particles with the coating material. The spraying process is not limited to using the toner manufacturing apparatus 1 of FIG. 1, and the toner manufacturing apparatus of FIG. 3A or FIG. 4 and a similar toner manufacturing apparatus may be used.

  The spraying of the liquid material in the spraying step is the same as the toner manufacturing method by the toner manufacturing apparatus 1. However, when the toner base particles are coated with a coating material to obtain toner particles, the temperature in the powder channel 2 is set to be equal to or lower than the glass transition temperature of the toner base particles. The temperature in the powder channel 2 is more preferably 30 ° C. or higher and the glass transition temperature of the toner base particles. The temperature in the powder channel 2 becomes almost uniform in any part in the powder channel 2 due to the flow of the toner base particles. When the temperature in the powder channel 2 exceeds the glass transition temperature of the toner base particles, the toner base particles are too soft in the powder channel 2 when the external additive dispersion is sprayed, and the toner base particles are aggregated. May occur. On the other hand, if the temperature in the powder flow path 2 is less than 30 ° C., the drying speed of the dispersion may be slowed and productivity may be reduced. Therefore, in order to prevent the aggregation of the toner base particles, the temperature of the powder flow path 2 is maintained in the powder flow path 2 as necessary, in order to maintain the temperature in the powder flow path 2 below the glass transition temperature of the toner base particles. It is necessary to provide means.

  When the toner is produced using the toner production method of the present invention, the coating material can be coated in a state where the toner base particles are isolatedly flowed, so that the aggregation of the toner base particles can be prevented. Further, toner mother particles adhere to the inner wall of the toner manufacturing apparatus, and other toner mother particles, coating materials contained in the liquid, and the like are prevented from aggregating and growing using the adhered toner mother particles as a core. Thus, the toner yield can be improved.

  Further, since the toner obtained by the toner manufacturing method of the present invention has a uniform coating amount of the coating material, toner characteristics such as charging characteristics between individual toner particles become uniform. Therefore, when an image is formed using such a toner, a high-definition image with good image quality without uneven density can be obtained.

  The toner particles produced as described above are responsible for functions such as powder flowability improvement, triboelectric chargeability improvement, heat resistance, long-term storage stability improvement, cleaning property improvement and photoreceptor surface wear property control. Additives may be mixed. Examples of the external additive include silica fine powder, titanium oxide fine powder, and alumina fine powder. One type of external additive can be used alone, or two or more types can be used in combination. The external additive is added in an amount of 0.1 to 100 parts by weight of the toner particles in consideration of the charge amount necessary for the toner, the effect of adding the external additive on the wear of the photoreceptor and the environmental characteristics of the toner. 1 to 10 parts by weight is preferred.

  The toner of the present invention thus produced is used for developing an electrostatic image when forming an image by electrophotography or electrostatic recording, or for developing a magnetic latent image when forming an image by magnetic recording. Can be used. Further, it can be used as a one-component developer or a two-component developer.

  The two-component developer of the present invention includes the toner and the carrier described above. Therefore, it is possible to obtain a two-component developer that suppresses environmental contamination without deteriorating the durability of the toner. Furthermore, since the two-component developer includes the toner, which is a highly transparent toner that can be applied to a color toner, a two-component developer capable of forming a high-quality image with high transparency is obtained. be able to.

  As the carrier, magnetic particles can be used. Specific examples of the particles having magnetism include metals such as iron, ferrite, and magnetite, and alloys of these metals with metals such as aluminum or lead. Among these, ferrite is preferable. Alternatively, a resin-coated carrier in which magnetic particles are coated with a resin, or a resin-dispersed carrier in which magnetic particles are dispersed in a resin may be used as the carrier. The resin that coats the magnetic particles is not particularly limited, and examples thereof include olefin resins, styrene resins, styrene / acrylic resins, silicone resins, ester resins, and fluorine-containing polymer resins. . Moreover, although it does not restrict | limit especially as resin used for a resin dispersion type carrier, For example, a styrene acrylic resin, a polyester resin, a fluorine resin, a phenol resin, etc. are mentioned.

The shape of the carrier is preferably a spherical shape or a flat shape. The volume average particle diameter of the carrier is not particularly limited, but is preferably 10 μm or more and 100 μm or less, and more preferably 20 μm or more and 50 μm or less, considering high image quality. Furthermore, the resistivity of the carrier is preferably 10 ⁸ Ω · cm or more, more preferably 10 ¹² Ω · cm or more. The carrier resistivity is determined by placing a carrier in a container having a cross-sectional area of 0.50 cm ² and tapping it, then applying a load of 1 kg / cm ² to the particles packed in the container and placing the load between the load and the bottom electrode. This is a value obtained by reading a current value when a voltage generating an electric field of 1000 V / cm is applied. When the resistivity is low, when a bias voltage is applied to the developing sleeve, charges are injected into the carrier, and carrier particles easily adhere to the photoreceptor. Further, breakdown of the bias voltage is likely to occur.

  The magnetization strength (maximum magnetization) of the carrier is preferably 10 emu / g or more and 60 emu / g or less, more preferably 15 emu / g or more and 40 emu / g or less. The magnetization strength depends on the magnetic flux density of the developing roller, but under the general magnetic flux density conditions of the developing roller, if it is less than 10 emu / g, the magnetic binding force does not work and causes carrier scattering. There is a fear. On the other hand, if the magnetization strength exceeds 60 emu / g, it is difficult to maintain a non-contact state with the image carrier in the non-contact development in which the carrier spikes are too high. Further, in the contact development, there is a risk that a sweep is likely to appear in the toner image.

  The usage ratio of the toner and the carrier in the two-component developer is not particularly limited and can be appropriately selected according to the type of the toner and the carrier. However, if the ferrite carrier is taken as an example, the toner is the total amount of the developer in the developer. The toner may be used so that it is contained in an amount of 2 wt% to 30 wt%, preferably 2 wt% to 20 wt%. In the two-component developer, the coverage of the carrier with the toner is preferably 40% by weight or more and 80% by weight or less.

  By using the two-component developer containing the toner obtained by the production method of the present invention, the toner characteristics such as the charging characteristics between the individual toner particles are uniform, so that the image quality is high and the density is not uniform. Images can be obtained.

  FIG. 5 is a cross-sectional view schematically showing the configuration of the image forming apparatus 100 according to the embodiment of the present invention. The image forming apparatus is a multifunction machine having both a copying function, a printer function, and a facsimile function, and forms a full-color or monochrome image on a recording medium according to transmitted image information. In other words, the image forming apparatus has three types of printing modes, ie, a copier mode (copying mode), a printer mode, and a facsimile mode. Operation input from an operation unit (not shown), personal computer, portable terminal device, information recording A print mode is selected by a control unit (not shown) in response to reception of a print job from an external device using a storage medium or a memory device. The image forming apparatus includes a toner image forming unit 102, a transfer unit 103, a fixing unit 104, a recording medium supply unit 105, and a discharge unit 106. Each member constituting the toner image forming unit 102 and some members included in the intermediate transfer unit 103 are black (b), cyan (c), magenta (m), and yellow (y) included in the color image information. In order to correspond to the image information of each color, four each are provided. Here, each member provided by four according to each color is distinguished by attaching an alphabet representing each color to the end of the reference symbol, and when referring collectively, only the reference symbol is used.

  The toner image forming unit 102 includes a photosensitive drum 111, a charging unit 112, an exposure unit 113, a developing unit 114, and a cleaning unit 115. The charging unit 112, the developing unit 114, and the cleaning unit 115 are arranged around the photosensitive drum 111 in this order. The charging unit 112 is disposed below the developing unit 114 and the cleaning unit 115 in the vertical direction.

  The photosensitive drum 111 is supported by a driving unit (not shown) so as to be rotatable around an axis, and includes a conductive substrate (not shown) and a photosensitive layer formed on the surface of the conductive substrate. The conductive substrate can take various shapes, and examples thereof include a cylindrical shape, a columnar shape, and a thin film sheet shape. Among these, a cylindrical shape is preferable. The conductive substrate is formed of a conductive material. As the conductive material, those commonly used in this field can be used. For example, metals such as aluminum, copper, brass, zinc, nickel, stainless steel, chromium, molybdenum, vanadium, indium, titanium, gold, platinum, etc. A conductive layer made of one or more of aluminum, aluminum alloy, tin oxide, gold, indium oxide and the like is formed on a film-like substrate such as two or more alloys, synthetic resin film, metal film, paper, etc. And a resin composition containing a conductive film, conductive particles and / or a conductive polymer. In addition, as a film-form base | substrate used for an electroconductive film, a synthetic resin film is preferable and a polyester film is especially preferable. Moreover, as a formation method of the electroconductive layer in an electroconductive film, vapor deposition, application | coating, etc. are preferable.

  The photosensitive layer is formed, for example, by laminating a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. In that case, it is preferable to provide an undercoat layer between the conductive substrate and the charge generation layer or the charge transport layer. By providing an undercoat layer, the scratches and irregularities present on the surface of the conductive substrate are coated to smooth the surface of the photosensitive layer, to prevent deterioration of the chargeability of the photosensitive layer during repeated use. Alternatively, an advantage of improving the charging characteristics of the photosensitive layer in a low humidity environment can be obtained. Further, a laminated photoreceptor having a three-layer structure having a high durability and having a photoreceptor surface protective layer as the uppermost layer may be used.

  The charge generation layer is mainly composed of a charge generation material that generates a charge when irradiated with light, and contains a known binder resin, plasticizer, sensitizer and the like as necessary. As the charge generation material, those commonly used in this field can be used, for example, perylene pigments such as perylene imide and perylene acid anhydride, polycyclic quinone pigments such as quinacridone and anthraquinone, metal and metal-free phthalocyanines, and halogenated compounds. Phthalocyanine pigments such as metal-free phthalocyanine, squalium dye, azulenium dye, thiapyrylium dye, carbazole skeleton, styryl stilbene skeleton, triphenylamine skeleton, dibenzothiophene skeleton, oxadiazole skeleton, fluorenone skeleton, bis stilbene skeleton, distyryl oxa And azo pigments having a diazole skeleton or a distyrylcarbazole skeleton. Among these, metal-free phthalocyanine pigments, oxotitanyl phthalocyanine pigments, bisazo pigments containing a fluorene ring and / or a fluorenone ring, bisazo pigments composed of aromatic amines, trisazo pigments, etc. have high charge generation ability and high sensitivity. Suitable for obtaining a photosensitive layer. One type of charge generating material can be used alone, or two or more types can be used in combination. The content of the charge generation material is not particularly limited, but is preferably 5 to 500 parts by weight, more preferably 10 to 200 parts by weight with respect to 100 parts by weight of the binder resin in the charge generation layer. As the binder resin for the charge generation layer, those commonly used in this field can be used. For example, melamine resin, epoxy resin, silicone resin, polyurethane, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polycarbonate, phenoxy resin , Polyvinyl butyral, polyarylate, polyamide, polyester and the like. Binder resin can be used individually by 1 type, or can use 2 or more types together as needed.

  The charge generation layer generates charge by dissolving or dispersing appropriate amounts of charge generation materials, binder resins and, if necessary, plasticizers and sensitizers in an appropriate organic solvent capable of dissolving or dispersing these components. It can be formed by preparing a layer coating solution, applying this charge generation layer coating solution to the surface of the conductive substrate and drying. The film thickness of the charge generation layer thus obtained is not particularly limited, but is preferably 0.05 to 5 μm, more preferably 0.1 to 2.5 μm.

  The charge transport layer laminated on the charge generation layer has a charge transport material having the ability to accept and transport the charge generated from the charge generation material and a binder resin for the charge transport layer as essential components. Contains known antioxidants, plasticizers, sensitizers, lubricants and the like. As the charge transport material, those commonly used in this field can be used, for example, poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensation product and derivatives thereof, Polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1-bis (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, pyrazoline Derivatives, phenylhydrazones, hydrazone derivatives, triphenylamine compounds, tetraphenyldiamine compounds, triphenylmethane compounds, stilbene compounds, 3-methyl-2-benzothiazoline -Donating substances such as azine compounds, fluorenone derivatives, dibenzothiophene derivatives, indenothiophene derivatives, phenanthrenequinone derivatives, indenopyridine derivatives, thioxanthone derivatives, benzo [c] cinnoline derivatives, phenazine oxide derivatives, tetracyano Examples include electron-accepting substances such as ethylene, tetracyanoquinodimethane, promanyl, chloranil, and benzoquinone. The charge transport materials can be used alone or in combination of two or more. The content of the charge transport material is not particularly limited, but is preferably 10 to 300 parts by weight, more preferably 30 to 150 parts by weight with respect to 100 parts by weight of the binder resin in the charge transport material. As the binder resin for the charge transport layer, those commonly used in this field and capable of uniformly dispersing the charge transport material can be used. For example, polycarbonate, polyarylate, polyvinyl butyral, polyamide, polyester, polyketone, epoxy resin, polyurethane , Polyvinyl ketone, polystyrene, polyacrylamide, phenol resin, phenoxy resin, polysulfone resin, and copolymer resins thereof. Among these, in consideration of film formability, wear resistance of the resulting charge transport layer, electrical characteristics, etc., polycarbonate containing bisphenol Z as a monomer component (hereinafter referred to as “bisphenol Z type polycarbonate”), bisphenol Z type polycarbonate And a mixture of polycarbonate with other polycarbonates are preferred. Binder resin can be used individually by 1 type, or can use 2 or more types together.

  The charge transport layer preferably contains an antioxidant together with the charge transport material and the binder resin for the charge transport layer. As the antioxidant, those commonly used in this field can be used, and examples thereof include vitamin E, hydroquinone, hindered amine, hindered phenol, paraphenylenediamine, arylalkane and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds. It is done. One antioxidant can be used alone, or two or more antioxidants can be used in combination. The content of the antioxidant is not particularly limited, but is 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on the total amount of components constituting the charge transport layer. The charge transport layer is dissolved or dispersed in a suitable organic solvent that can dissolve or disperse these components in an appropriate amount such as a charge transport material and a binder resin, and if necessary, an antioxidant, a plasticizer, and a sensitizer. The charge transport layer coating liquid is prepared, and the charge transport layer coating liquid is applied to the surface of the charge generation layer and dried. The film thickness of the charge generation layer thus obtained is not particularly limited, but is preferably 10 to 50 μm, more preferably 15 to 40 μm. Note that a photosensitive layer in which a charge generation material and a charge transport material are present can be formed in one layer. In that case, the type, content, binder resin, and other additives of the charge generation material and the charge transport material may be the same as in the case of separately forming the charge generation layer and the charge transport layer.

  In this embodiment, the photosensitive drum formed by forming the organic photosensitive layer using the charge generation material and the charge transport material as described above is used. Instead, an inorganic photosensitive layer using silicon or the like is formed. Can be used.

  The charging unit 112 faces the photosensitive drum 111 and is disposed so as to be separated from the surface of the photosensitive drum 111 along the longitudinal direction of the photosensitive drum 111 with a gap, and the surface of the photosensitive drum 111 has a predetermined polarity and Charge to potential. As the charging unit 112, a charging brush type charger, a charger type charger, a sawtooth type charger, an ion generator, or the like can be used. In the present embodiment, the charging unit 112 is provided so as to be separated from the surface of the photosensitive drum 111, but is not limited thereto. For example, a charging roller may be used as the charging unit 112, and the charging roller may be disposed so that the charging roller and the photosensitive drum are in pressure contact with each other, or a contact charging type charger such as a charging brush or a magnetic brush may be used. .

  The exposure unit 113 is arranged so that light of each color information emitted from the exposure unit 113 passes between the charging unit 112 and the developing unit 114 and is irradiated on the surface of the photosensitive drum 111. The exposure unit 113 branches the image information into light of each color information of b, c, m, and y in the unit, and the surface of the photosensitive drum 111 charged to a uniform potential by the charging unit 112 is light of each color information. To form an electrostatic latent image on the surface. As the exposure unit 113, for example, a laser scanning unit including a laser irradiation unit and a plurality of reflection mirrors can be used. In addition, a unit in which an LED array, a liquid crystal shutter, and a light source are appropriately combined may be used.

  FIG. 6 is a cross-sectional view schematically showing the configuration of the developing unit 114 according to the embodiment of the present invention. The developing unit 114 includes a developing tank 120 and a toner hopper 121. The developing tank 120 is disposed so as to face the surface of the photosensitive drum 111, and is a container that supplies toner to an electrostatic latent image formed on the surface of the photosensitive drum 111 and develops it to form a visible toner image. It is a shaped member. The developing tank 120 accommodates toner in its internal space and accommodates a roller member such as a developing roller, a supply roller, and a stirring roller, or a screw member, and rotatably supports the developing tank 120. An opening is formed in a side surface of the developing tank 120 facing the photosensitive drum 111, and a developing roller is rotatably provided at a position facing the photosensitive drum 111 through the opening. The developing roller is a roller-like member that supplies toner to the electrostatic latent image on the surface of the photoconductor 111 at the pressure contact portion or the closest portion with the photoconductor drum 111. When supplying the toner, a potential having a polarity opposite to the charging potential of the toner is applied to the surface of the developing roller as a developing bias voltage (hereinafter simply referred to as “developing bias”). As a result, the toner on the surface of the developing roller is smoothly supplied to the electrostatic latent image. Further, by changing the developing bias value, the amount of toner (toner adhesion amount) supplied to the electrostatic latent image can be controlled. The supply roller is a roller-like member provided so as to be able to rotate and face the developing roller, and supplies toner around the developing roller. The agitating roller is a roller-like member that faces the supply roller and can be driven to rotate, and feeds toner newly supplied from the toner hopper 121 into the developing tank 120 around the supply roller. The toner hopper 121 is provided so that a toner replenishing port (not shown) provided at the lower part in the vertical direction communicates with a toner receiving port (not shown) provided at the upper part in the vertical direction of the developing tank 120. The toner is replenished according to the toner consumption status of 120. Further, the toner hopper 121 may not be used, and the toner may be directly supplied from each color toner cartridge.

  By developing using the two-component developer of the present invention, a good toner image with high definition and no density unevenness can be formed on the photoreceptor.

  The cleaning unit 115 removes the toner remaining on the surface of the photosensitive drum 111 after the toner image is transferred to the recording medium, and cleans the surface of the photosensitive drum 11. For the cleaning unit 115, for example, a plate-like member such as a cleaning blade is used. In the image forming apparatus of the present invention, an organic photosensitive drum is mainly used as the photosensitive drum 111, and the surface of the organic photosensitive drum is mainly composed of a resin component. Deterioration of the surface is likely to proceed due to the chemical action of ozone generated by. However, the deteriorated surface portion is worn by receiving a rubbing action by the cleaning unit 115 and is gradually but surely removed. Therefore, the problem of surface deterioration due to ozone or the like is practically solved, and the charging potential by the charging operation can be stably maintained over a long period of time. Although the cleaning unit 115 is provided in this embodiment, the present invention is not limited to this, and the cleaning unit 15 may not be provided.

  According to the toner image forming unit 102, the surface of the photosensitive drum 111 that is uniformly charged by the charging unit 112 is irradiated with signal light corresponding to image information from the exposure unit 113 to form an electrostatic latent image. Toner is supplied from the developing unit 114 to form a toner image, and the toner image is transferred to the intermediate transfer belt 125. Then, the toner remaining on the surface of the photosensitive drum 111 is removed by the cleaning unit 115. This series of toner image forming operations is repeatedly executed.

  The transfer unit 103 is disposed above the photosensitive drum 111, and includes an intermediate transfer belt 125, a driving roller 126, a driven roller 127, an intermediate transfer roller 128 (b, c, m, y), and a transfer belt cleaning unit. 129 and the transfer roller 130. The intermediate transfer belt 125 is an endless belt-like member that is stretched by a driving roller 126 and a driven roller 127 to form a loop-shaped movement path, and is driven to rotate in the direction of an arrow B. When the intermediate transfer belt 125 passes through the photosensitive drum 111 while being in contact with the photosensitive drum 111, the intermediate transfer roller 128 disposed on the surface of the photosensitive drum 111 via the intermediate transfer belt 125 faces the photosensitive drum 111. A transfer bias having a polarity opposite to the charging polarity of the toner is applied, and the toner image formed on the surface of the photosensitive drum 111 is transferred onto the intermediate transfer belt 125. In the case of a full-color image, each color toner image formed on each photoconductor drum 111 is sequentially transferred onto the intermediate transfer belt 125 to form a full-color toner image. The driving roller 126 is provided so as to be rotatable around its axis by driving means (not shown), and the intermediate transfer belt 125 is driven to rotate in the direction of arrow B by the rotational driving. The driven roller 127 is provided so as to be able to be driven and rotated by the rotational drive of the driving roller 126, and applies a constant tension to the intermediate transfer belt 125 so that the intermediate transfer belt 1 25 does not loosen. The intermediate transfer roller 128 is provided in pressure contact with the photosensitive drum 111 via the intermediate transfer belt 125, and can be driven to rotate about its axis by a driving unit (not shown). The intermediate transfer roller 128 is connected to a power source (not shown) for applying a transfer bias as described above, and has a function of transferring the toner image on the surface of the photosensitive drum 111 to the intermediate transfer belt 125. The transfer belt cleaning unit 129 is provided so as to face the driven roller 127 through the intermediate transfer belt 125 and to contact the outer peripheral surface of the intermediate transfer belt 125. The toner adhering to the intermediate transfer belt 125 due to contact with the photosensitive drum 111 causes the back surface of the recording medium to be contaminated. Therefore, the transfer belt cleaning unit 129 removes and collects the toner on the surface of the intermediate transfer belt 125. The transfer roller 130 is in pressure contact with the driving roller 1 26 via the intermediate transfer belt 125, and is provided so as to be rotationally driven around an axis line by a driving means (not shown). At the pressure contact portion (transfer nip portion) between the transfer roller 130 and the drive roller 126, the toner image carried and conveyed by the intermediate transfer belt 125 is transferred to the recording medium fed from the recording medium supply means 105 described later. Is done. The recording medium carrying the toner image is fed to the fixing unit 104. According to the transfer unit 103, the toner image transferred from the photosensitive drum 111 to the intermediate transfer belt 125 at the pressure contact portion between the photosensitive drum 111 and the intermediate transfer roller 128 rotates the intermediate transfer belt 125 in the arrow B direction. It is conveyed to a transfer nip portion by driving, and transferred to a recording medium there.

  The fixing unit 104 is provided downstream of the transfer unit 103 in the conveyance direction of the recording medium, and includes a fixing roller 131 and a pressure roller 132. The fixing roller 131 is rotatably provided by a driving unit (not shown), and heats and melts toner constituting an unfixed toner image carried on the recording medium to fix it on the recording medium. A heating unit (not shown) is provided inside the fixing roller 131. The heating unit heats the fixing roller 131 so that the surface of the fixing roller 131 reaches a predetermined temperature (heating temperature). For example, a heater or a halogen lamp can be used as the heating means. The heating means is controlled by fixing condition control means described later. The control of the heating temperature by the fixing condition control means will be described in detail later. A temperature detection sensor is provided near the surface of the fixing roller 131 to detect the surface temperature of the fixing roller 131. The detection result by the temperature detection sensor is written in the storage unit of the control means described later. The pressure roller 132 is provided so as to be in pressure contact with the fixing roller 131, and is supported so as to be driven to rotate by the rotation drive of the pressure roller 132. The pressure roller 132 assists the fixing of the toner image to the recording medium by pressing the toner and the recording medium when the toner is melted and fixed on the recording medium by the fixing roller 131. A pressure contact portion between the fixing roller 131 and the pressure roller 132 is a fixing nip portion. According to the fixing unit 104, the recording medium onto which the toner image is transferred by the transfer unit 103 is sandwiched between the fixing roller 131 and the pressure roller 132, and the toner image is recorded under heating when passing through the fixing nip portion. By being pressed against the medium, the toner image is fixed on the recording medium and an image is formed.

  The recording medium supply unit 105 includes an automatic paper feed tray 135, a pickup roller 136, a transport roller 137, a registration roller 138, and a manual paper feed tray 139. The automatic paper feed tray 135 is a container-like member that is provided in the lower part of the image forming apparatus in the vertical direction and stores a recording medium. Recording media include plain paper, color copy paper, overhead projector sheets, postcards, and the like. The pick-up roller 136 takes out the recording medium stored in the automatic paper feed tray 135 one by one and feeds it to the paper transport path S1. The conveyance rollers 137 are a pair of roller members provided so as to be in pressure contact with each other, and convey the recording medium toward the registration rollers 138. The registration rollers 138 are a pair of roller members provided so as to be in pressure contact with each other, and the recording medium fed from the conveyance roller 137 is used to convey the toner image carried on the intermediate transfer belt 125 to the transfer nip portion. Synchronously, it is fed to the transfer nip. The manual paper feed tray 139 is a device that takes a recording medium into the image forming apparatus by manual operation. The recording medium taken from the manual paper feed tray 139 passes through the paper conveyance path S2 by the conveyance roller 37, and It is fed to the registration roller 138. According to the recording medium supply unit 105, a toner image carried on the intermediate transfer belt 125 is conveyed to the transfer nip portion of the recording medium supplied one by one from the automatic paper feed tray 135 or the manual paper feed tray 139. In synchronism with this, the sheet is fed to the transfer nip portion.

  The discharge unit 106 includes a conveyance roller 137, a discharge roller 140, and a discharge tray 141. The conveyance roller 137 is provided on the downstream side of the fixing nip portion in the sheet conveyance direction, and conveys the recording medium on which the image is fixed by the fixing unit 104 toward the discharge roller 140. The discharge roller 140 discharges the recording medium on which the image is fixed to a discharge tray 141 provided on the upper surface in the vertical direction of the image forming apparatus. The discharge tray 141 stores a recording medium on which an image is fixed.

The image forming apparatus 100 includes a control unit (not shown). The control unit is provided, for example, in an upper part of the internal space of the image forming apparatus, and includes a storage unit, a calculation unit, and a control unit. In the storage unit of the control means, various setting values via an operation panel (not shown) arranged on the upper surface of the image forming apparatus, detection results from sensors (not shown) arranged at various locations inside the image forming apparatus, Image information and the like are input. In addition, programs for executing various means are written. Examples of the various means include a recording medium determination unit, an adhesion amount control unit, and a fixing condition control unit. As the storage unit, those commonly used in this field can be used, and examples thereof include a read only memory (ROM), a random access memory (RAM), and a hard disk drive (HDD). As the external device, an electric / electronic device that can form or acquire image information and can be electrically connected to the image forming apparatus can be used. For example, a computer, a digital camera, a television, a video recorder, a DVD recorder, Examples include an HDVD, a Blu-ray disc recorder, a facsimile machine, and a mobile terminal device. The arithmetic unit takes out various data (image formation command, detection result, image information, etc.) written in the storage unit and programs of various means, and performs various determinations. The control unit sends a control signal to the corresponding device according to the determination result of the calculation unit, and performs operation control. The control unit and the calculation unit are central processing units (CPU,
A processing circuit realized by a microcomputer, a microprocessor, or the like having a Central Processing Unit) is included. The control means includes a main power supply together with the processing circuit described above, and the power supply supplies power not only to the control means but also to each device in the image forming apparatus.

  By forming an image using an image forming apparatus provided with the developing device of the present invention, it is possible to obtain a high-definition and good-quality image having no density unevenness.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In the following, “parts” and “%” mean “parts by weight” and “% by weight” unless otherwise specified. The viscosity of the liquid, the glass transition temperature of the binder resin and the toner base particles, the softening temperature of the binder resin, the melting point of the release agent, and the volume average particle size of the toner base particles in the examples and comparative examples are as follows. Measured.

[Viscosity of liquid]
Using a cone plate type viscometer RE105L type (manufactured by Toki Sangyo Co., Ltd.), the liquid was stirred at 25 ° C. and 100 rpm, and the value obtained 5 minutes after the measurement data was stabilized was taken as the viscosity of the liquid.

[Glass transition temperature of binder resin and toner base particles]
Using a differential scanning calorimeter (trade name: DSC220, manufactured by Seiko Denshi Kogyo Co., Ltd.), according to Japanese Industrial Standard (JIS) K7121-1987, 1 g of a sample was heated at a heating rate of 10 ° C. per minute and a DSC curve was measured. did. Draw the endothermic peak corresponding to the glass transition of the obtained DSC curve at a point where the slope is maximum with respect to the straight line that extends the base line on the high temperature side to the low temperature side and the curve from the rising part of the peak to the vertex. The temperature at the intersection with the tangent was determined as the glass transition temperature (Tg).

[Softening temperature of binder resin]
In a flow characteristic evaluation apparatus (trade name: Flow Tester CFT-100C, manufactured by Shimadzu Corporation), a load of 20 kgf / cm ² (9.8 × 10 ⁵ Pa) was applied to give 1 g of a sample (nozzle diameter 1 mm, length). 1 mm), and heated at a heating rate of 6 ° C. per minute. The temperature at which half of the sample flowed out from the die was determined and used as the softening temperature (Tm).

[Melting point of release agent]
Using a differential scanning calorimeter (trade name: DSC220, manufactured by Seiko Denshi Kogyo Co., Ltd.), 1 g of the sample was heated from a temperature of 20 ° C. to 150 ° C. at a heating rate of 10 ° C. per minute, and then rapidly cooled from 150 ° C. to 20 ° C. The operation was repeated twice and the DSC curve was measured. The temperature at the top of the endothermic peak corresponding to the melting of the DSC curve measured in the second operation was determined as the melting point of the release agent.

[Volume average particle size]
20 ml of a sample and 1 ml of sodium alkyl ether sulfate are added to 50 ml of an electrolytic solution (trade name: ISOTON-II, manufactured by Beckman Coulter, Inc.), and ultrasonic waves are applied using an ultrasonic disperser (trade name: UH-50, manufactured by STM). A sample for measurement was prepared by dispersion treatment at a frequency of 20 kHz for 3 minutes. This sample for measurement was measured using a particle size distribution measuring device (trade name: Multisizer 3, manufactured by Beckman Coulter, Inc.) under the conditions of aperture diameter: 20 μm, number of measured particles: 50000 count, and volume particle size distribution of sample particles. From this, the volume average particle size was determined.

Example 1
[Preparation of toner base particles]
・ Polyester resin (trade name: Toughton, manufactured by Kao Corporation, glass transition temperature 70 ° C., softening temperature 130 ° C.)
87.5% (100 parts)
・ C. I. Pigment Red 122 5.0% (5.7 parts)
Paraffin wax (trade name: HNP-10, manufactured by Nippon Seiki Co., Ltd., melting point 70 ° C.)
6.0% (6.9 parts)
・ Charge control agent (trade name: N4P, manufactured by Clariant)
1.5% (1.7 parts)

  Each of the above components was premixed with a Henschel mixer (trade name: FM20C, manufactured by Mitsui Mining Co., Ltd.) and then melt-kneaded with a twin-screw extrusion kneader (trade name: PCM65, manufactured by Ikekai Co., Ltd.). This melt-kneaded product is coarsely pulverized with a cutting mill (trade name: VM-16, manufactured by Orient Co., Ltd.), then finely pulverized with a jet mill (manufactured by Hosokawa Micron Co., Ltd.), and further an air classifier (manufactured by Hosokawa Micron Co., Ltd.). Thus, toner mother particles having a volume average particle diameter of 6.5 μm and a glass transition temperature of 67 ° C. were produced.

[Preparation of liquid]
Acrylic resin (trade name: JDX-C3000 manufactured by Johnson Polymer Co., Ltd.) 5.0 parts, ethanol (trade name: special grade ethanol 99.5, manufactured by Kishida Chemical Co., Ltd.) 90 parts, and resin fine particles (trade name: MP-5000, (Made by Soken Chemical Co., Ltd.) 5.0 parts and stirred and mixed at 8000 rpm for 20 minutes using a homogenizer (trade name: Polytron PT-MR3100, manufactured by Kinematica), the acrylic resin is dissolved in ethanol and the resin fine particles are dispersed. A prepared liquid was prepared. The viscosity of the obtained liquid was 10 cP.

[Spraying process]
A hybridization system (trade name: NHS-1 type, manufactured by Nara Machinery Co., Ltd.) similar to the apparatus shown in FIG. 1 is provided with a two-fluid nozzle and an adhesion prevention unit made of PTFE. The particles were sprayed with a liquid. As in the apparatus shown in FIG. 1, the adhesion preventing portion is formed on the downstream portion of the spraying means with respect to the powder flow direction on the inner wall of the powder passage and the opening formed on one surface in the axial direction of the stirring portion. It was provided in the vicinity. In this apparatus, the peripheral speed at the outermost periphery of the rotating stirring means of the hybridization system was 72 m / s. The spray rate of the liquid was 5 g / min. The mounting angle of the two-fluid nozzle was set so that the liquid spraying direction and the powder flow direction were parallel. With such an apparatus, 100 parts by weight of the prepared toner base particles were sprayed with the liquid material until 9 parts by weight of the acrylic resin was coated, whereby the toner of Example 1 was obtained.

(Example 2)
In the spraying process, the mounting speed of the two-fluid nozzle is set so that the spraying speed of the liquid is 10 g / min, and the angle between the liquid spraying direction and the powder flow direction (hereinafter referred to as “spraying angle”) is 25 °. The toner of Example 2 was obtained in the same manner as Example 1 except that was set.

(Example 3)
In the liquid preparation process, the blending ratio of acrylic resin and ethanol is changed to obtain a liquid having a viscosity of 47 cP, and in the spraying process, the peripheral speed at the outermost periphery of the rotary stirring means is set to 118 m / s. The toner of Example 3 was obtained in the same manner as in Example 1 except that the spray rate was 21 g / min and the mounting angle of the two-fluid nozzle was set so that the spray angle was 43 °.

Example 4
In the liquid preparation process, the blending ratio of acrylic resin and ethanol is changed to obtain a liquid having a viscosity of 23 cP, and in the spraying process, the peripheral speed at the outermost periphery of the rotary stirring means is set to 100 m / s. The toner of Example 4 was obtained in the same manner as in Example 1 except that the spraying speed was 18 g / min and the mounting angle of the two-fluid nozzle was set so that the spraying angle was 48 °.

(Example 5)
In the liquid preparation process, the blending ratio of acrylic resin and ethanol is changed to obtain a liquid having a viscosity of 37 cP, and in the spraying process, the peripheral speed at the outermost periphery of the rotary stirring means is 100 m / s, The toner of Example 5 was obtained in the same manner as in Example 1 except that the spraying speed was 25 g / min and the mounting angle of the two-fluid nozzle was set so that the spraying angle was 48 °.

(Example 6)
In the liquid preparation process, a blending ratio of acrylic resin and ethanol is changed to obtain a liquid having a viscosity of 51 cP, and in the spraying process, the peripheral speed at the outermost periphery of the rotary stirring means is 100 m / s, A toner of Example 6 was obtained in the same manner as in Example 1 except that the spraying speed was 25 g / min and the mounting angle of the two-fluid nozzle was set so that the spraying angle was 25 °.

(Example 7)
In the liquid preparation process, the blending ratio of acrylic resin and ethanol is changed to obtain a liquid having a viscosity of 51 cP, and in the spraying process, the peripheral speed at the outermost periphery of the rotating stirring means is 101 m / s, A toner of Example 7 was obtained in the same manner as in Example 1 except that the spray speed was 10 g / min and the mounting angle of the two-fluid nozzle was set so that the spray angle was 48 °.

(Example 8)
In the liquid preparation process, a blending ratio of acrylic resin and ethanol is changed to obtain a liquid having a viscosity of 51 cP, and in the spraying process, the peripheral speed at the outermost periphery of the rotary stirring means is 100 m / s, The toner of Example 8 was obtained in the same manner as in Example 1, except that the spraying speed was 25 g / min and the mounting angle of the two-fluid nozzle was set so that the spraying angle was 48 °.

Example 9
In the spraying process, the toner of Example 9 was used in the same manner as in Example 1 except that a Q-type mixer (manufactured by Hosokawa Micron Corporation) was used instead of the hybridization system and the spraying process was performed under the following conditions. Obtained.

[Spraying process]
A liquid material was sprayed on the toner base particles by a device in which a two-fluid nozzle was attached to a Q-type mixer similar to the device shown in FIG. 3A and an adhesion preventing portion made of PTFE was provided. The adhesion preventing part was provided on the entire inner surface of the processing container, as in the apparatus shown in FIG. In this apparatus, the peripheral speed at the outermost periphery of the rotary stirring means was 75 m / s. The spray rate of the liquid was 18 g / min. Also, the mounting angle of the two-fluid nozzle was set so that the liquid spray direction was perpendicular to the rotation axis of the rotary stirring means. By using such an apparatus, the liquid material was sprayed so that 9 parts by weight of the acrylic resin was coated on 100 parts by weight of the prepared toner base particles, whereby the toner of Example 9 was obtained.

(Comparative Example 1)
A toner of Comparative Example 1 was obtained in the same manner as in Example 1 except that in the spraying step, the peripheral speed at the outermost periphery of the rotary stirring means was 69 m / s and the spray speed of the liquid material was 18 g / min.

(Comparative Example 2)
In the spraying process, a toner of Comparative Example 2 was obtained in the same manner as in Example 1 except that a device without an adhesion preventing part was used and the spraying speed of the liquid was 18 g / min.

(Comparative Example 3)
In the spraying process, the same apparatus as in Example 1 was used, except that an apparatus without an adhesion preventing part was used, the peripheral speed at the outermost periphery of the rotary stirring means was 50 m / s, and the spraying speed of the liquid was 18 g / min. Thus, a toner of Comparative Example 3 was obtained.

(Comparative Example 4)
In the spraying step, the toner of Comparative Example 4 was obtained in the same manner as in Example 1 except that the peripheral speed at the outermost periphery of the rotary stirring means was 123 m / s and the spray speed of the liquid material was 18 g / min.

(Comparative Example 5)
In the spraying process, the toner of Comparative Example 5 was used in the same manner as in Example 1 except that a Q-type mixer (manufactured by Hosokawa Micron Corporation) was used instead of the hybridization system and the spraying process was performed under the following conditions. Obtained.

[Spraying process]
The liquid material was sprayed on the toner base particles by a device in which a two-fluid nozzle was attached to the Q-type mixer. Similar to the apparatus shown in FIG. 3A, the two-fluid nozzle was mounted so that the liquid spray direction was perpendicular to the rotation axis of the rotary stirring means. In this apparatus, the peripheral speed at the outermost periphery of the rotary stirring means was 50 m / s. The spray rate of the liquid was 18 g / min. Also, the mounting angle of the two-fluid nozzle was set so that the liquid spray direction was perpendicular to the rotation axis of the rotary stirring means. With such an apparatus, the liquid material was sprayed so that 9 parts by weight of the acrylic resin was coated on 100 parts by weight of the prepared toner base particles, whereby the toner of Comparative Example 5 was obtained.

  The obtained toners of Examples and Comparative Examples were evaluated for yield and coating uniformity as follows.

<yield>
The toner yield was calculated according to the following formula.
Toner yield = weight of recovered toner particles
/ (Toner base particle input amount + solid weight of coating material) × 100

  When the calculated toner yield is 95%, ◎ (very good), 90% to less than 95% ○ (good), 80% to less than 90% △ (no problem in practical use), 80% Less than was evaluated as x (defect).

<Coating uniformity>
For the toner mother particles before and after the treatment, the number average particle size distribution was obtained and evaluated by the amount of change of the coefficient of variation in this distribution. The variation coefficient is a value obtained by standard deviation σ / number average particle diameter D × 100 (%), and (variation coefficient after processing−variation coefficient before treatment) was calculated as the variation amount of the variation coefficient. When the surface of the toner base particles is completely uniformly coated, the variation amount of the variation coefficient becomes 0, and the larger the variation amount of the variation coefficient, the more uneven the coating. When the variation amount of the coefficient of variation is less than 5, ◎ (very excellent coating uniformity), when 5 or more but less than 10, ○ (good coating uniformity), when 10 or more and less than 15 Δ (practically there is no problem in coating uniformity), and the case of 15 or more was evaluated as x (poor coating uniformity).

The number average particle size distribution was determined by adding 20 mg of a sample and 1 ml of sodium alkyl ether sulfate to 50 ml of an electrolytic solution (trade name: ISOTON-II, manufactured by Beckman Coulter, Inc.), an ultrasonic disperser (trade name: UH-50, A sample for measurement was prepared by dispersion treatment at an ultrasonic frequency of 20 kHz for 3 minutes using an STM product. The measurement sample was obtained by measuring using a particle size distribution measuring device (trade name: Multisizer 3, manufactured by Beckman Coulter, Inc.) under the conditions of aperture diameter: 20 μm and number of measured particles: 50000 count. When the rate of change in standard deviation is less than 5%: ◎ (very good), 5% or more but less than 10% ○ (good), 10% or more but less than 30% △ (no problem in practical use), 30% or more Was evaluated as x (defect).
The evaluation results are shown in Table 1.

  As shown in Table 1, it can be seen that the toner production method of the present invention is excellent in yield and coating uniformity.

1 is a cross-sectional view illustrating a configuration of a toner manufacturing apparatus 1 according to an embodiment of the present invention. FIG. 3 is a front view showing a configuration around a powder charging unit 6 and a powder recovery unit 7. It is a figure which shows the structure of the toner manufacturing apparatus 31 which is other embodiment of this invention. It is a figure which shows the structure of the toner manufacturing apparatus 31 which is other embodiment of this invention. FIG. 6 is a front sectional view showing a configuration of a toner manufacturing apparatus 41 according to another embodiment of the present invention. 1 is a cross-sectional view schematically showing a configuration of an image forming apparatus 100 that is an embodiment of the present invention. It is sectional drawing which shows typically the structure of the developing means 114 which is embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,31,41 Toner manufacturing apparatus 2 Powder flow path 3,33,42 Spraying means 4,34 Rotation stirring means 5 Adhesion prevention part 6 Powder input part 7 Powder collection part 8 Stirring part 9 Powder flow part DESCRIPTION OF SYMBOLS 10,11 Opening part 12 Supply pipe 13,17 Electromagnetic valve 14,35 Powder particle flow direction 15 Collection tank 16 Collection pipe 18 Rotating shaft member 19 Turntable 20 Stirring blade 21 Through-hole 32 Processing container 35 Container main body 36 Cover body 37 Adhesion Prevention Unit 38 Rotor 39 Stirring Blade 100 Image Forming Device 114 Developing Unit

Claims (10)

In the powder flow path by rotation of the rotary stirring means including the rotation shaft, the toner base particles consisting only of the binder resin, the colorant, the release agent and the charge control agent are caused to flow, the coating material seen including, by spraying the liquid material viscosity is less than 50cP at 25 ° C. from the spray means, the method for producing a toner for coating a coating material to the toner mother particles,
The peripheral speed at the outermost periphery of the rotary stirring means is 70 m / s or more and 120 m / s or less,
A toner manufacturing method, wherein an adhesion preventing part for preventing adhesion of toner base particles to an inner wall of a powder channel is provided on at least a part of the inner wall of the powder channel.   The toner manufacturing method according to claim 1, wherein the adhesion preventing portion includes a fluororesin.   3. The toner manufacturing method according to claim 1, wherein the spraying means sprays the liquid material at a rate of 20 g or less per minute. A powder flow path is provided so that the toner base particles flow in a constant powder flow direction,
The method for producing a toner according to any one of claims 1 to 3, wherein an angle formed between a liquid spray direction from the spraying means and a powder flow direction is 45 ° or less.   The method for producing a toner according to claim 1, wherein the spray direction of the liquid material from the spraying unit is perpendicular to the rotation axis of the rotating stirring unit.   The method for producing a toner according to claim 1, wherein the spray direction of the liquid from the spraying unit is parallel to the rotation axis of the rotating stirring unit. Toner characterized by being obtained by the method for producing a toner according to any one of claims 1-6. A two-component developer comprising the toner according to claim 7 and a carrier. A developing device that performs development using the two-component developer according to claim 8 . An image forming apparatus comprising the developing device according to claim 9 .

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