JP4376757B2 - Toner for developing electrostatic image, two-component developer, process cartridge, image forming apparatus, and image forming method - Google Patents

Description

  The present invention relates to a two-component developer for developing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing, and the like, an image forming apparatus using the developer, and a process cartridge. More specifically, the present invention relates to a developer for developing an electrostatic image and an image forming apparatus used for a copying machine, a laser printer, a plain paper fax machine, and the like using a direct or indirect electrophotographic developing system. Further, the present invention relates to a developer for electrostatic image development and an image forming apparatus used for a full-color copying machine, a full-color laser printer, a full-color plain paper fax machine and the like using a direct or indirect electrophotographic multicolor developing system.

In recent years, with the improvement in quality of image forming apparatuses such as copiers and printers, higher image quality of output images has been pursued, and it is desired that the toner for image formation has a small particle size and a spherical shape. . When the toner has a small particle diameter and a spherical shape, the behavior of each toner base during development is uniform, and the reproducibility of minute dots is remarkably improved.
However, these toners still have problems to be solved. One of them is to ensure uniform chargeability.

  One of the factors that hinder the uniform chargeability of the toner is a fine powder toner generated during the external additive treatment. This is mainly caused by adding, mixing and adhering various external additives to the surface of the toner base to ensure fluidity, when the toner base is subjected to shearing force, and the toner base is deformed and broken. is there. Since this fine toner is highly charged, it adheres firmly to the surface of the carrier, thereby reducing the charging sites of the carrier and reducing its charging ability. For this reason, there is a problem that the replenishment toner cannot obtain a sufficient charge amount, and the charge amount between the toner in the agent and the replenishment toner is different, resulting in background staining.

Conventionally, wet methods and dry methods have been adopted as methods for treating external additives.
In the wet method, the solution used in the manufacturing process tends to remain in the toner system, resulting in poor frictional charging characteristics and odor problems due to the residual solution during use. Need to be removed by drying. For this reason, the toner manufacturing operation from the solution becomes very complicated and causes a significant decrease in workability.
On the other hand, in the dry processing method, since the external additive is processed by stirring and mixing in the gas phase without using a solvent, the disadvantages of the wet processing method can be eliminated. Since the particles are frequently subjected to mechanical external force such as stirring in the developing device, the toner particles are easily broken and fine powder is easily generated. The fine powder contaminates the carrier particles and reduces the charging ability of the carrier particles. In particular, in the case of a surface treatment agent aiming at charge control, in order to obtain uniform triboelectric charging, not only these are attached to the toner base surface, but also a part or all of them are buried uniformly and firmly fixed. In order to do so, it must be mixed at a stirring speed that gives a sufficient impact force. For this reason, the fine toner is more likely to be generated.

Further, in recent years, toner for electrophotography has progressed to low-temperature fixing, and a binder resin having a low glass transition temperature is preferably used as a binder resin. When such a toner is to be stirred and mixed, It is necessary to perform the treatment at a temperature at which the toner or the low melting point substance in the toner does not melt, the temperature range in the surface treatment process of the external additive is limited, and it is necessary to fix the toner with sufficient impact force. Become.
That is, as in the case described above, fine powder is likely to be generated due to the impact during stirring. As a result, an insufficiently charged toner is generated, and the toner contaminates the developer transport carrier and other devices, thereby causing problems such as a decrease in image density, paper smudge, fogging, and carrier adhesion.
Therefore, in order to reliably process the external additive and to prevent the occurrence of the above-mentioned problems associated with the generation of the fine powder toner even for the toner having a spherical shape and a low-temperature fixability, the fine powder content contained in the toner It is desirable to control.

For example, in Patent Document 1, at least a binder resin and a colorant are contained, and the toner is measured by a Coulter counter by adding hydrophobic silica particles having a primary average particle size of 30 to 50 nm to a toner base. Has a volume average particle diameter (Dv) of 5 μm to 8 μm, a fine powder content of 5 μm or less is less than 20% by number, and a number-based circle equivalent diameter measured by a flow particle image analyzer is 0.6 μm. There has been proposed a one-component electrostatic charge developing toner, an image forming method, and an image forming apparatus characterized in that the content of particles of less than 3 μm is 15% or less. Thereby, an abnormal image such as white spots does not occur, and a high-quality output image can be maintained over a long period of time.
However, Patent Document 1 has a configuration limited to the one-component development method, and does not suppress the occurrence of fogging due to a difference in charge amount between the toner in the developer and the replenishment toner for the two-component developer.

Further, in Patent Document 2, in a toner containing at least a binder resin, a colorant, and a release agent, the volume average particle diameter (D ₄ ) of the toner measured by a Coulter counter is 5 μm to 8 μm, and 5 μm. The following fine powder content rate is 60 to 75% by number, and the content rate of particles whose number-based equivalent circle diameter measured by a flow type particle image analyzer is 0.6 μm or more and 3 μm or less is 25% or less. A featured image forming toner is disclosed.
Further, in Patent Document 3, in a toner contained in a developer used in an image forming method including at least a non-contact fixing method as an image fixing method, a volume average particle diameter (Dv) in a measurement value of the toner by a multisizer. And the number average particle diameter (Dn) ratio Dv / Dn is 1.15 to 1.58, wherein the fine powder content of 4 μm or less is 15% or less. A toner for developer is disclosed.
However, the invention described in Patent Document 2 improves the low-temperature fixability of the toner, and does not suppress the occurrence of fog due to a difference in charge amount between the toner in the developer and the replenishment toner. Further, the invention described in Patent Document 3 provides a toner having excellent fixing quality even in an image forming method using a non-contact fixing method, and the difference in charge amount between the toner in the developer and the replenishing toner is provided. Not for controlling.

JP 2002-351133 A JP 2001-330988 A JP 2003-295495 A Japanese Patent Laid-Open No. 5-34971

Therefore, the present invention has been made in view of the above circumstances, and in an image forming apparatus having a toner replenishment mechanism, even when a low-temperature fixing toner is used, the charge control agent is reliably fixed on the surface thereof. Another object of the present invention is to provide an excellent electrostatic charge image developing toner and two-component developer that are free from fogging due to a difference in charge amount between the toner in the developer and the replenishment toner, and that do not deteriorate the developer.
It is another object of the present invention to provide a process cartridge and an image forming apparatus that are excellent in low-temperature fixability and that do not generate fog even immediately after toner replenishment and can provide high-quality images.

The features of the present invention, which is a means for solving the above problems, are listed below.
1. The electrostatic image developing toner of the present invention is a toner used in a two-component developer containing a silicone coat carrier and a toner, and at least a binder resin, a colorant and a release agent are used as oil droplets in a solvent. obtain toner base by removing the solvent from the dispersed emulsified dispersion, the toner base, the preparative toner obtained by external addition treatment with the charge control agent and no fine particles, the toner is replenished The average circularity measured by the flow type particle image analyzer is 0.930 to 0.965, and the content of fine powder of 3 μm or less is 5 to 20% by number in the developing device after replenishment. In the toner, the content of fine powder of 3 μm or less is 5 to 70% by number.
2. The toner for developing an electrostatic charge image of the present invention includes: The toner according to the invention is characterized in that the addition amount of the charge control agent is 0.2 to 1.0% by weight with respect to the toner base.
3. The toner for developing an electrostatic charge image of the present invention includes: Or 2. In the invention described in item 3, the inorganic fine particles are silica and / or titanium.
4). The toner for developing an electrostatic charge image of the present invention includes: Or 3. In the invention according to any one of the above, the toner base is prepared by dissolving or dispersing a composition containing a compound having an active hydrogen group, a colorant, and a release agent in at least an organic solvent, It is obtained by dispersing the dispersion in an aqueous medium and reacting or reacting a compound having an active hydrogen group with the resin capable of reacting, removing the organic solvent, washing and drying. It is characterized by.
5. The toner for developing an electrostatic charge image of the present invention includes: Or 4. In the invention according to any one of the above, the toner base is characterized in that the ratio Dv / Dn of the volume average particle diameter Dv to the number average particle diameter Dn is 1.25 or less.

6). The developer of the present invention is a developer for developing an electrostatic latent image formed on a latent image carrier, and is a two-component developer containing a silicone coat carrier and a toner. No 5. The toner according to any one of the above is used.
7). The developer of the present invention is 6. In the invention described in item 3, the silicone-coated carrier has a coating layer containing at least a silicone resin and / or carbon, has a weight average particle diameter of 45 to 65 μm, and a content ratio of carrier particles having a particle diameter of less than 37 μm. Is 0 to 15% by weight.

8). The image forming method of the present invention includes a step of forming an electrostatic latent image on an image carrier and a step of developing the electrostatic latent image with a developer containing an electrostatic charge image developing toner to form a toner image. And an image forming method including a step of transferring a toner image onto a transfer target member and a step of fixing the toner image on the transfer target member. Or 7. The developer described in 1) is used.

9. The image forming apparatus of the present invention includes at least a latent image carrier that carries a latent image, a charging device that has a charging member that uniformly charges the surface of the image carrier, and an electrostatic latent image on the surface of the charged image carrier. An exposure device for writing an image, a developing device for visualizing an electrostatic latent image formed on the surface of the image carrier with toner on the developer carrier, and a visualized toner image on the image carrier directly or 5. An image forming apparatus comprising: a transfer device that transfers to a recording medium via an intermediate transfer member; and a fixing device that fixes a toner image on the recording medium with heat and / or pressure. Or 7. The developer described in 1. is filled.
10. The image forming apparatus according to the present invention is described in 9. The latent image carrier is an amorphous silicon photoconductor.
11. The image forming apparatus according to the present invention is described in 9. Or 10. In the invention described in item 1, the alternating voltage is applied when developing the latent image on the latent image carrier.
12 The image forming apparatus according to the present invention is described in 9. To 11. In the invention according to any one of the above, the fixing device includes a heating body provided with a heating element, a film in contact with the heating body, and a pressure member in pressure contact with the heating body through the film. The fixing device is characterized in that the recording material on which an unfixed image is formed is passed between the film and the pressure member to heat and fix.
13. The image forming apparatus according to the present invention is described in 9. Or 12. In any of the inventions, the charging device is a charging device that performs charging by bringing a charging member into contact with the latent image carrier and applying a voltage to the charging member.

14 In addition, the process cartridge of the present invention integrally supports at least one image carrier and at least one unit selected from a charging unit, a developing unit, and a cleaning unit, and is detachable from the main body of the image forming apparatus. A cartridge, wherein the developing means is 6. Or 7. The developer described in (1) is retained.

By means of solving the above-mentioned problems, the present invention is able to achieve a difference in the charge amount between the toner in the developer and the replenishment toner while securely fixing the charge control agent on the surface of the low-temperature fixing toner mainly composed of a thermoplastic resin. By eliminating the above, it is possible to provide an excellent toner for developing an electrostatic charge image and a two-component developer which are free from fogging and free from developer deterioration.
In addition, it is possible to provide a process cartridge and an image forming apparatus that are excellent in low-temperature fixability and do not cause fog on an image.

Hereinafter, the present invention will be described in detail.
(Replenishment and toner fine powder content of 3μm or less in developer)
The content of fine powder of 3 μm or less in the replenishing toner used in the present invention is preferably 5 to 20% by number, and more preferably 5 to 15% by number. The fine powder content of 3 μm or less of the toner in the developer is preferably 5 to 70% by number, more preferably 5 to 50% by number.
When the fine powder content of 3 μm or less of the toner in the developer exceeds 70% by number, the highly charged fine powder toner adheres firmly to the carrier surface, thereby reducing the charging site of the carrier and lowering the charging ability of the carrier. Therefore, the replenishment toner cannot obtain a sufficient charge amount, and the charge amount of the toner in the agent and the replenishment toner is different from each other, resulting in background staining. If it is less than 5% by number, the problem of deteriorating fixability occurs because it does not play the role of filling the gap between the particles. Further, if the content of fine powder of 3 μm or less in the replenishment toner exceeds 20% by number, the accumulation speed of the fine powder toner in the carrier is increased, the charging site of the carrier is reduced, the charging ability of the carrier is lowered, and a sufficient charge amount is obtained. It disappears and the background becomes dirty. Furthermore, when the particle size distribution becomes broad, the charge amount distribution also becomes broad, resulting in a difference in charge amount and background stains. If it is less than 5% by number, the problem of deteriorating fixability occurs because it does not play the role of filling the gap between the particles.
Thus, by defining the content of fine powder of 3 μm or less in the replenishment toner and the toner in the developer within the above range, it is possible to suppress a decrease in the charging ability of the carrier and to obtain a sufficient charge amount of the toner. As a result, it is possible to obtain a good image free from background stains.
As described above, since the charge control of the toner can be performed by means that does not depend on the stirring and mixing treatment method, it can be used as a means corresponding to the low-temperature fixing toner.

(Average circularity of replenishment toner)
The average circularity of the replenishing toner used in the present invention is preferably 0.930 to 0.965. When the average circularity is 0.965 or more, since the shape is round, even if the amount of fine powder is small, a large amount of toner passes through the photosensitive member and the cleaning blade, resulting in a new problem of poor cleaning. When the average circularity is 0.930 or less, the transfer rate decreases, the toner shape changes during long-term image passing, especially the pulverization increases the fine powder content, and the image quality such as background stains decreases. cause. Therefore, it is necessary to control the average circularity to 0.930 to 0.965.

(Measurement of fine powder content, volume average particle size, average circularity of 3 μm or less)
An outline of a Coulter counter and a flow type particle image apparatus used for measuring particles in the present invention is shown. The volume average particle diameter was measured by connecting a number distribution and volume distribution interface (manufactured by Nikka) and a PC9801 personal computer (manufactured by NEC) to a Coulter Counter TAII manufactured by Coulter Electronics, USA. The electrolyte was adjusted to a 1% NaCl aqueous solution using primary sodium chloride. As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 50 to 100 ml of the electrolytic solution, and 1 to 10 mg of a sample is added. This is subjected to a dispersion treatment for 1 minute with an ultrasonic disperser, 100 to 200 ml of an electrolytic aqueous solution is put into another beaker, the sample dispersion is added to a predetermined concentration therein, and the Coulter Counter TA- Measure the particle size distribution of 30000 particles of 2 to 40 μm based on the number using 100 μm aperture as an aperture according to type II, calculate the volume distribution and number distribution of 2 to 40 μm particles, and the fine powder content is 3 μm or less, The volume average particle diameter (Dv: the median value of each channel is the representative value of the channel) was determined.
The average circularity can be measured using a flow type particle image analyzer FPIA-2100 manufactured by Sysmex Corporation. An outline of the apparatus and measurement is described in JP-A-8-136439. The measurement was adjusted to a 1% NaCl aqueous solution using primary sodium chloride and then passed through a 0.45 μm filter to 50 to 100 ml of a surfactant, preferably 0.1 to 5 ml of an alkylbenzene sulfonate as a dispersant. In addition, add 1-10 mg of sample. This was subjected to dispersion treatment for 1 minute with an ultrasonic disperser, and measurement was performed using a dispersion liquid in which the particle concentration was adjusted to 5000 to 15000 particles / μl. For the measurement of the number of particles, a two-dimensional image area captured by a CCD camera and a diameter of a circle having the same area are calculated as an equivalent circle diameter. From the accuracy of the CCD pixel, a particle equivalent measurement diameter of 0.6 μm or more in diameter was obtained.

(Image forming apparatus and process cartridge)
This two-component developer can be used, for example, in an image forming apparatus having a process cartridge as shown in FIG.
FIG. 1 is a schematic configuration diagram of a tandem color image forming apparatus according to the present invention.
In the present invention, a plurality of components such as the above-described image carrier (hereinafter referred to as a photoreceptor) 40, charging device 60, developing device, and cleaning means are integrally coupled as a process cartridge. The process cartridge is configured to be detachable from the main body of an image forming apparatus such as a copying machine or a printer.
In the image forming apparatus having a process cartridge using the two-component developer, the photosensitive member 40 is rotationally driven at a predetermined peripheral speed. In the rotating process, the photosensitive member 40 is uniformly charged with a predetermined positive or negative potential on the peripheral surface thereof by the charging device 60, and then is supplied from the image exposure device 21 such as slit exposure or laser beam scanning exposure. In response to the image exposure light, an electrostatic latent image is sequentially formed on the peripheral surface of the photoreceptor 40. The formed electrostatic latent image is then developed with toner by a developing device, and the developed toner image is fed. The transfer device sequentially transfers the transfer material P fed from the unit 200 between the photoconductor 40 and the transfer device 22 in synchronization with the rotation of the photoconductor 40. The transfer material P that has received the image transfer is separated from the surface of the photoconductor 40, introduced into the image fixing device 25, where the image is fixed, and printed out as a copy (copy). The surface of the photoconductor 40 after the image transfer is cleaned by removing toner remaining after transfer by the cleaning device 63, and after being further neutralized, it is repeatedly used for image formation.

(Development means)
FIG. 2 is a schematic cross-sectional view showing a schematic configuration of the developing device of the present invention. The two-component developer can be developed in, for example, the developing device shown in FIG. The developing device 61 of this embodiment shown in FIG. 2 includes a developing sleeve that conveys the developer to the photoreceptor, a mixing / stirring screw that mixes and charges the replenishing toner with the carrier, and the like.
The toner is pulverized in the developing device 61 during mixing / stirring and transported on the developing sleeve to generate fine powder. In particular, the influence of the mixing / stirring screw is great. Examples of the mixing / stirring screw include a spiral screw and a screw having an elliptic blade. Furthermore, the developer is also stressed by the number of rotations of the mixing / stirring screw. Further, this stress is not easily affected by toner having a high average circularity of 0.930 to 0.965 and high circularity, but it cannot be completely prevented from being pulverized and generating fine powder. The toner is less likely to generate fine powder as the average particle size is smaller. However, similarly, the generation of pulverized fine powder cannot be completely prevented. Therefore, in the developing device 61 using toner having an average circularity of 0.930 to 0.965, 3 μm or less and a fine powder content of 5 to 20% by number, in the case of a spiral mixing / stirring screw, the rotation speed is 150 to 400 rpm. In the range. Thus, the toner in the developing device 61 can be used over a long period of time within a range of 5 to 70% by number of fine powder content of 3 μm or less. If the rotational speed is less than 150 rpm, the replenished toner does not generate fine powder, but charging is not sufficient and toner scattering occurs, resulting in a problem that the inside of the image forming apparatus is soiled. When the rotational speed exceeds 400 rpm, the generation of fine powder exceeds 70% by number, the replenishment toner is insufficiently charged and fogging occurs. In addition, the chargeability of the carrier due to toner spent may be reduced, thereby causing image unevenness.

(Primary particle size and amount added of charge control agent)
The primary particle diameter of the charge control agent used in the present invention is preferably 100 to 300 nm. If the primary particle size is 100 nm or less, the mass is too small, so that it floats in the stirring vessel and cannot be sufficiently immobilized on the surface of the resin powder, and a sufficient charge amount cannot be obtained. Further, when the primary particle diameter is 300 nm or more, the charge control agent immobilized on the surface of the resin powder is not uniform depending on the individual resin powder, so that the charge amount varies. Moreover, it is preferable that it is 0.2-1.0 wt% with respect to resin powder, and, as for addition amount, More preferably, it is 0.25-0.70 wt%. If it is less than 0.2 wt%, the effect as a charge control agent cannot be obtained, and background stains due to insufficient charging ability occur. If it is 1.0 wt% or more, the effect as a charge control agent becomes strong, the charge amount of the toner in the developer becomes high, a difference from the charge amount of the replenishing toner occurs, and background stains occur.
Any known charge control agent can be used, and the primary particle size is preferably 100 to 300 nm. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus Simple substance or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E- 84, E-89 of a phenol-based condensate (manufactured by Orient Chemical Industry Co., Ltd.), TP-302 of a quaternary ammonium salt molybdenum complex, TP-415 (manufactured by Hodogaya Chemical Industry Co., Ltd.), quaternary ammonium Copy charge PSY VP2038 of salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit), copper phthalocyanine, perylene, quinacridone Azo pigments, sulfonate group, carboxyl group, and polymer compounds having a functional group such as a quaternary ammonium salt.

(Silicone coat carrier)
The two-component developer of the present invention is a mixture of toner and magnetic carrier, and the content ratio of carrier to toner in the developer is preferably 1 to 10 parts by weight of toner with respect to 100 parts by weight of carrier. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used.
As the coating material, a material containing at least a silicone resin and / or carbon is preferable. Specific examples include polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral, and aminoacrylate resin. Among these, a silicone resin is more preferable. Carbon can control the developability of the toner by adjusting the conductivity of the coating resin. When the amount of carbon is large, carrier adhesion increases, and the amount of addition is determined by the carrier particle size, the toner charge amount, the peripheral speed of the photoreceptor, and the like.
Silicone varnish (made by Toshiba, TSR 115, TSR 114, TSR 102, TSR 103, YR 3061, TSR 110, TSR 116, TSR 117, TSR 108, TSR 109, TSR 180, TSR 181, TSR 187, TSR) 144, TSR 165, manufactured by Shin-Etsu Silicone Co., Ltd., KR 271, KR 272, KR 275, KR 280, KR 282, KR 267, KR 269, KR 211, KR 212, etc.) Alkyd modified silicone varnish (TSR 184, 185 manufactured by Toshiba, etc.) ), Epoxy-modified silicone varnishes (such as TSR 194, YS54 manufactured by Toshiba), polyester-modified silicone varnishes (such as TSR 187 manufactured by Toshiba), acrylic-modified silicone varnishes (such as TSR 170, 171 manufactured by Toshiba), Urethane (such as Toshiba TSR 175) modified silicone varnishes, reactive silicone resin (Shin-Etsu Silicone Co. KA1008, KBE1003, KBC1003, such as KBM 303, KBM 403, KBM 503, KBM 602, KBM 603), and the like.
In the present invention, the carrier particles used have a weight average particle diameter of 45 to 65 μm, and the content of carrier particles having a particle diameter of less than 37 μm is preferably 0 to 15% by weight. preferable. If it exceeds 15% by weight, carrier adhesion occurs.

(Influence of Tg)
In recent years, toners for electrophotography have been lowered in melting point, and the glass transition temperature Tg of the resin powder is usually 40 to 70 ° C. In order to efficiently fix the charge control agent on the resin powder without degrading the quality by stirring and mixing, it is desirable to treat in the temperature range of (Tg-35) to (Tg-10) ° C. based on Tg. . At T <Tg−35 ° C., there is no heat generation due to collision between the stirring blade and the powder or between the powders, that is, sufficient immobilization is not achieved. Conversely, when T> Tg−10 ° C., the heat generation amount exceeds the cooling capacity. For example, in electrophotographic toner, the release agent contained in the resin powder particles is exposed on the particle surface. Such toner has a problem that storage stability is lowered and the inside of the copying machine is soiled.
Further, since the low melting point material is melted and a toner aggregate is formed by fusing, a new classification and removal process is required for use as an electrophotographic toner, which is not efficient. In general, toner has a tendency to generate heat as its fluidity is poor, and particularly when the toner is fixed at a low temperature (low melting point), the toner fluidity is deteriorated and easily generates heat. In the present invention, as will be described later, inorganic fine particles are added as a fluidity aid to improve fluidity. As a result, the fluidity can be improved, and it is effective for preventing an increase in the calorific value.

(Fluid mixing mixer)
<Container shape 1>
As the fluid agitation type mixing device in the present invention, a container that does not have a fixing member protruding from the inner wall of the container is preferable, and there are no portions or irregularities protruding from the inner wall of the container arranged around the rotating body on the inner wall. A spherical container that does not form a gap between the projection member and the protruding member is preferable. In the case of a device having irregularities on the container wall surface, for example, a hybridizer as shown in FIG. 1 in Patent Document 4, since the toner collides with the container wall surface due to high speed rotation, friction and heat generation, a part of the toner is fused. Agglomeration or the release agent may be exposed to change the toner physical properties. When there is a protruding portion, the protruding height of the member from the inner wall surface of the container is preferably 1 mm or less, more preferably 0.5 mm or less. By allowing the powder to flow through the smooth inner wall at high speed, the surface of the powder can be uniformly treated without further pulverization of the particles. If there are protrusions on the inner wall and it is not smooth, turbulent flow is likely to occur in the high-speed air stream, excessive pulverization of particles, local melting of the toner base surface, and lack of uniformity of processing to the powder Variation) is likely to occur. The protruding member from the inner wall surface of the container according to the present invention includes, for example, a sensor for measuring the internal temperature and a member protruding in the direction of the axis of the rotating body that prevents the powder from adhering to the inner wall. I can't.

<Container shape 2>
Furthermore, the shape of the processing container is preferably a cylindrical shape or an inner wall that is not a flat shape, is a substantially spherical body having no flat portion on the inner wall, and has a continuous curved surface. Other than the continuous curved surface, a powder discharge device, a gas discharge port, and the like are not included. Such a continuous curved surface creates a stable and undisturbed high-speed air flow, and creates uniformity of energy given between particles including the resin powder to be processed. For example, a Q-type mixer (manufactured by Mitsui Mining Co., Ltd.) is a suitable example.

<Fan and immobilization>
In order to immobilize the surface treatment agent on the toner base, it is important to increase the number of collisions between the blades and the powder or between the powders, and to strike the inner wall direction with a large centrifugal force. The powder must be rotated and given a sufficient impact force. The impact force received from the blades when colliding with the rotating blades has the maximum rotational direction component, and therefore the blade shape that can transmit as much rotational direction component force as possible to the powder, for example, is located radially. A stirring blade is desirable.

(Stirring speed)
The stirring speed (circumferential speed) is 65 to 120 m / s, preferably 70 to 100 m / s. By stirring at a speed in this range, a large impact force is applied to each toner base, and the toner base driven out by the impact force has a large speed, so that it can move in the stirring container at a high speed.
Combining the conditions of the treatment temperature, the stirring device and the stirring speed described above is highly effective in driving the surface treatment agent onto the toner surface.

(Effects of processing conditions and Tg aggregation)
When stirring and mixing is performed within the above temperature range based on Tg, the degree of toner aggregation changes depending on the container capacity, the amount charged, and the peripheral speed of the impeller. This is an index as to how much the surface treatment agent is fixed to the resin powder. Further, when agitation and mixing of a resin powder having a degree of aggregation greater than 70 and, for example, a charge control agent, if the agitation mixer used in the present invention is used, inorganic fine particles and fluid particles in the initial stage of mixing are used as fluidity aids. Since the charge control agent functions as a flow aid, it is possible to control the degree of aggregation.

(Average particle diameter Dv of toner base)
The resin powder in the present invention preferably has a volume average particle diameter Dv of 3.0 to 7.0 μm. If the Dv is less than 3.0 μm, the mass of the powder is too small, so that it is difficult to fix with the energy amount that can be applied by the stirring blade. Further, when Dv exceeds 7.0 μm, the particles are crushed, and not only the Dv after the treatment is changed but also the quality is affected.

(Dv / Dn)
The resin powder in the present invention preferably has a Dv / Dn of 1.25 or less. When Dv / Dn exceeds 1.25, the particle size distribution of the powder is broad and the flowability is poor, so that not only the heat generation during driving is increased, but also the charge control agent cannot be uniformly attached, affecting the quality. Will be affected.

(Addition amount of inorganic fine particles and primary particle size)
As the inorganic fine particles of the flow aid in the present invention, the amount of the inorganic fine particles added to the resin powder is preferably in the range of 0.1 to 1.0 wt%, more preferably 0.30 to 0.70 wt%. is there. If the addition amount is less than 0.1 wt%, the effect as a fluidity aid cannot be obtained and heat is generated. If it exceeds 1.0 wt%, no heat is generated, but a large amount of inorganic fine particles are present on the surface of the resin powder, which inhibits low-temperature fixability. Moreover, what has a primary particle diameter of 5-150 nm is preferable, More preferably, it is 10-50 nm. If the primary particle diameter is less than 5 nm, the mass is too small, and the inside of the stirring vessel floats, so that the fluidity effect as a fluidity aid cannot be obtained. On the other hand, if the primary particle diameter exceeds 150 nm, the fluidity effect as a fluidity aid cannot be obtained.
Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, silica and titanium oxide are particularly preferable. These inorganic fine particles can be surface treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. In particular, when titanium oxide is used, deterioration of charging characteristics can be effectively prevented.

(Binder resin)
<Urea-modified polyester>
In order to produce the resin powder used in the present invention, it is preferable to include a modified polyester resin as a composition as a binder resin. As this modified polyester resin, polyester (i) modified with a urea bond can be used. Examples of (i) include a reaction product of a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a product obtained by further reacting a polyester having an active hydrogen group with a polyisocyanate (3), which is a polycondensate of a polyol (1) and a polycarboxylic acid (2), etc. Is mentioned. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

  Examples of the polyol (1) include a diol (1-1) and a trivalent or higher polyol (1-2). (1-1) alone or (1-1) and a small amount of (1-2) Is preferred. Diol (1-1) includes alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts. Among these, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyol (1-2) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2). (2-1) alone and (2-1) with a small amount of ( A mixture with 2-2) is preferred. Dicarboxylic acid (2-1) includes alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acid (phthalic acid, isophthalic acid, terephthalic acid) , Naphthalenedicarboxylic acid, etc.). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polycarboxylic acid (2), you may make it react with polyol (1) using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.

The ratio of the polyol (1) and the polycarboxylic acid (2) is usually 2/1 to 1/1, preferably 1. as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 5/1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.
Examples of the polyisocyanate (3) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; And a combination of two or more of these.

  The ratio of the polyisocyanate (3) is usually 5/1 to 1/1, preferably 4 /, as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. If the molar ratio of [NCO] is less than 1, the urea content in the modified polyester will be low, and the hot offset resistance will deteriorate. The content of the polyisocyanate (3) component in the prepolymer (A) having an isocyanate group at the terminal is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.

The number of isocyanate groups contained per molecule in the prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2.5 on average. It is. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.
As amines (B), diamine (B1), trivalent or higher polyamine (B2), aminoalcohol (B3), aminomercaptan (B4), amino acid (B5), and amino acids B1 to B5 blocked (B6) etc. are mentioned. Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexylmethane, diamines). Cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the block (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazoline compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

Furthermore, if necessary, the molecular weight of the urea-modified polyester can be adjusted using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
The ratio of amines (B) is the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). In general, it is 1/2 to 2/1, preferably 1 / 1.5 to 1.5 / 1, and more preferably 1 / 1.2 to 1.2 / 1. When [NCO] / [NHx] exceeds 2 or less than 1/2, the molecular weight of the urea-modified polyester (i) becomes low, and the hot offset resistance deteriorates.

In the present invention, the polyester (i) modified with a urea bond may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.
The urea-modified polyester (i) used in the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the urea-modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.

(Unmodified polyester)
In the present invention, not only the polyester (i) modified with the urea bond but also the polyester (ii) not modified with the (i) can be contained as a binder resin component of the toner. By using (ii) in combination, the low-temperature fixability and gloss when used in a full-color device are improved, which is preferable to single use. Examples of (ii) include the same polycondensates of polyol (1) and polycarboxylic acid (2) as in the above-mentioned polyester component (i), and preferred ones are also the same as (i). Further, (ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, for example, may be modified with a urethane bond. It is preferable that (i) and (ii) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, the polyester component (i) and (ii) preferably have similar compositions. When (ii) is contained, the weight ratio of (i) to (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. If the weight ratio of (i) is less than 5%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.
The peak molecular weight of (ii) is preferably 1000 to 10,000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (ii) is usually 1-30, preferably 5-20. By having an acid value, it tends to be negatively charged.
In the present invention, the glass transition point (Tg) of the binder resin of the toner is preferably 40 to 70 ° C. If it is less than 40 ° C., the heat-resistant storage stability of the toner is deteriorated, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Due to the coexistence of the urea-modified polyester resin, the dry toner of the present invention tends to have good heat-resistant storage stability even when the glass transition point is low, as compared with known polyester-based toners.

As the storage elastic modulus of the binder resin, the temperature (TG ′) at which the measurement frequency is 20 Hz is 10000 dyne / cm ² is usually 100 ° C. or higher, preferably 110 to 200 ° C. If it is less than 100 ° C., the resistance to hot offset deteriorates. As the viscosity of the binder resin of the toner, the temperature (Tη) at 1000 P (100 Pa · s) at a measurement frequency of 20 Hz is usually 180 ° C. or less, preferably 90 to 160 ° C. If it exceeds 180 ° C., the low-temperature fixability deteriorates. That is, from the viewpoint of achieving both low temperature fixability and hot offset resistance, TG ′ is preferably higher than Tη. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or higher. More preferably, it is 10 degreeC or more, Most preferably, it is 20 degreeC or more. The upper limit of the difference is not particularly limited. Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 0 to 100 ° C. More preferably, it is 10-90 degreeC, Most preferably, it is 20-80 degreeC.

(Coloring agent)
As the colorant used in the toner of the present invention, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow oxidation Iron, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sae Red, parac Luort Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake , Thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyra Ron Red, Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indance Ren Blue (RS, BC), Indigo, Ultramarine Blue, Bituminous Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green , Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lakes, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, ritbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15 wt%, preferably 3 to 10 wt%, based on the toner.

The colorant used in the present invention can also be used as a master batch combined with a resin. As a binder resin to be kneaded together with the production of the master batch or the master batch, in addition to the modified and unmodified polyester resins mentioned above, styrene such as polystyrene, poly p-chlorostyrene, and polyvinyltoluene, and polymers of substitution products thereof. Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer Polymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α -Methyl chloromethacrylate copolymer, styrene-a Lilonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester Styrene copolymers such as copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid Examples thereof include resins, rosins, modified rosins, terpene resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes, and the like, which can be used alone or in combination.
The master batch is obtained by mixing and kneading a resin for a master batch and a colorant with a high shear force. In this case, an organic solvent can be used in order to enhance the interaction between the colorant and the resin. In addition, a so-called flushing method called watering paste containing water of a colorant is mixed and kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove moisture and organic solvent components. Since it can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shearing dispersion device such as a three-roll mill is preferably used.

(Release agent)
In addition to the binder resin and the colorant, the resin powder contains a wax as a release agent. Known waxes can be used, and examples thereof include polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbon (paraffin wax, sasol wax, etc.); carbonyl group-containing wax. Of these, carbonyl group-containing waxes are preferred. Carbonyl group-containing waxes include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18 -Octadecanediol distearate, etc.); polyalkanol esters (trimellitic acid tristearyl, distearyl maleate, etc.); polyalkanoic acid amides (ethylenediamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide, etc.) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred.
The melting point of the wax as a release agent is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature. Further, the melt viscosity of the wax is preferably 5 to 1000 cps (0.005 to 1 Pa · s), more preferably 10 to 100 cps (0.01 to 0.1 Pa · s) as a measured value at a temperature 20 ° C. higher than the melting point. s). Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability. The wax content in the toner is usually 40 wt% or less, preferably 3 to 30 wt%.

(Charge control agent immobilization treatment)
Examples of a method for producing a resin powder composed of at least a binder resin, a colorant and a release agent include, for example, a pulverization method in which a binder resin, a colorant and a release agent are melt-kneaded and then pulverized and classified, Examples include a polymerization method in which a resin, a colorant, and a release agent are dispersed as oil droplets in a solvent to cause a polymerization reaction.
In order to use the resin powder prepared by these methods as an electrophotographic toner, it is uniformly stirred and mixed together with inorganic fine particles as a charge control agent and a fluidity auxiliary agent for improving the triboelectric charging ability, thereby improving the charging stability. In order to obtain it, it is necessary to fix it securely. As a device, a spherical mixer provided with an impeller is suitable. When a charge control agent is driven in as a surface treatment agent, the agglomeration degree after stirring and mixing of the resin powder, the charge control agent and the inorganic fine particles is 20 to 70%, preferably 25 to 60%, more preferably 30 to 50%. High chargeability if present.

(Melting and kneading method)
Toner components such as a binder resin, a colorant, and a release agent are mechanically mixed. This mixing step may be performed under normal conditions using a normal mixer or the like with rotating wings, and is not particularly limited. When the above mixing process is completed, the mixture is then charged into a kneader and melt-kneaded. As the melt kneader, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used. It is important that this melt-kneading is performed under appropriate conditions so as not to cause the molecular chains of the binder resin to be broken. Specifically, the melt-kneading temperature should be performed with reference to the softening point of the binder resin. If the temperature is lower than the softening point, cutting is severe, and if the temperature is too high, dispersion does not proceed. When the above melt-kneading process is completed, the kneaded product is then pulverized. In this pulverization step, it is preferable to first coarsely pulverize and then finely pulverize. At this time, a method of pulverizing by colliding with a collision plate in a jet stream or pulverizing with a narrow gap between a rotor and a stator that rotate mechanically is preferably used. After this pulverization step is completed, the pulverized product is classified in an air stream with a centrifugal force or the like to produce a predetermined particle size, for example, a volume average particle size of 3.0 to 7.0 μm.
The dry toner constituting the two-component developer of the present invention can be produced by the following method, but is not limited thereto.

(Toner production method in aqueous medium)
As a preferred binder resin for forming the resin powder, urea-modified polyester can be used as described above.
The toner base (resin powder) may be formed by reacting a dispersion comprising a prepolymer (A) having an isocyanate group in an aqueous medium with amines (B), or a urea-modified polyester produced in advance. (I) may be used.
As a method for stably forming a dispersion comprising urea-modified polyester (i) or prepolymer (A) in an aqueous medium, a toner raw material comprising urea-modified polyester (i) or prepolymer (A) in an aqueous medium is used. And a method of dispersing by shearing force. The prepolymer (A) and other toner compositions (hereinafter referred to as toner raw materials), such as a colorant, a colorant masterbatch, a release agent, and an unmodified polyester resin, are used when forming a dispersion in an aqueous medium. It is preferable to mix the toner raw materials in advance, and then add and disperse the mixture in an aqueous medium. In the present invention, other toner raw materials such as a colorant and a release agent are not necessarily mixed when forming particles in an aqueous medium, and are added after the particles are formed. Also good. For example, after forming particles containing no colorant, the colorant can be added by a known dyeing method.
In this case, the necessary aqueous medium may be water alone, or a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohols (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like.

The dispersion method is not particularly limited, and known equipment such as a low-speed shear type, a high-speed shear type, a friction type, a high-pressure jet type, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferable. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C. Higher temperatures are preferable in that the dispersion of the urea-modified polyester (i) or prepolymer (A) has a low viscosity and is easily dispersed.
The amount of the aqueous medium used relative to 100 parts of the toner composition containing the urea-modified polyester (i) and the prepolymer (A) is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner composition is poor and a toner base having a predetermined particle diameter cannot be obtained. If it exceeds 2000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.

In the step of synthesizing the urea-modified polyester (i) from the prepolymer (A), the amine (B) may be added and reacted before the toner composition is dispersed in the aqueous medium, or may be dispersed in the aqueous medium. An amine (B) may be added later to cause a reaction from the particle interface. In this case, urea-modified polyester is preferentially produced on the surface of the manufactured toner, and a concentration gradient can be provided inside the particles.
Anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, and alkylamines as dispersants for emulsifying and dispersing the oily phase in which the toner composition is dispersed in a liquid containing water Amine salts such as salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazolines, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, etc. Nonionic surfactants such as quaternary ammonium salt type cationic surfactants, fatty acid amide derivatives, polyhydric alcohol derivatives, such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl- N, N Amphoteric surfactants such as dimethyl ammonium betaine and the like.

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (C6 to C11). Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carboxylic acid and its metal Salts, perfluoroalkyl carboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2 hydroxyethyl ) Perfluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate Etc.
Trade names of anionic surfactants include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.) ), Unidyne DS-101, DS-102 (Daikin Kogyo Co., Ltd.), Megafac F-l10, F-120, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.) , EXTOP EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), Futgent F-100, F150 (manufactured by Neos), etc. It is done.
Examples of the cationic surfactant include aliphatic primary, secondary or tertiary amine acids having a fluoroalkyl group, aliphatic quaternary ammonium salts such as perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, benza Luconium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass), Florard FC-135 (Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Megafac F-150, F-824 (manufactured by Dainippon Ink, Inc.), Xtop EF-132 (manufactured by Tochem Products), and Footgent F-300 (manufactured by Neos).

Further, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite and the like can be used as an inorganic compound dispersant that is hardly soluble in water.
Further, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-acrylate Chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N- Methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc., or esters of compounds containing vinyl alcohol and carboxyl groups, such as acetic acid Vinyl, vinyl propionate, vinyl butyrate, etc., acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine, etc. Homopolymers or copolymers such as those having a nitrogen atom or its heterocyclic ring, polyoxyethylene, polyoxypropylene, polyoxyethylene alkyl Such as amine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonyl phenyl ester Celluloses such as polyoxyethylene, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and the like can be used.
In addition, when an acid such as calcium phosphate salt or an alkali-soluble substance is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and then washing with water. To do. It can also be removed by an operation such as degradation with an enzyme. When a dispersant is used, the dispersant can remain on the surface of the toner base, but it is preferable from the charged surface of the toner to be washed and removed after the elongation and / or crosslinking reaction.

  Furthermore, in order to lower the viscosity of the toner composition, a solvent in which the urea-modified polyester (i) or the prepolymer (A) is soluble can be used. The use of a solvent is preferable in that the particle size distribution becomes sharp. The solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal. Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, Methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride are preferred. The usage-amount of the solvent with respect to 100 parts of prepolymers (A) is 0-300 parts normally, Preferably it is 0-100 parts, More preferably, it is 25-70 parts. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after the elongation and / or crosslinking reaction.

The elongation and / or crosslinking reaction time is selected depending on the reactivity of the isocyanate group structure of the prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. is there. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.
In order to remove the organic solvent from the obtained emulsified dispersion, a method in which the temperature of the entire system is gradually raised to completely evaporate and remove the organic solvent in the droplets can be employed. Alternatively, the emulsified dispersion can be sprayed into a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and the aqueous dispersant can be removed by evaporation together. . As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air currents heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. Sufficient target quality can be obtained by short-time treatment such as spray dryer, belt dryer, rotary kiln.

When the particle size distribution at the time of emulsification dispersion is wide and washing and drying processes are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classifying into a desired particle size distribution.
The classification operation can be performed by removing the fine particle portion in a liquid by a cyclone, a decanter, centrifugation, or the like. Of course, the classification operation may be performed after obtaining the powder as a powder after drying. The unnecessary fine particles or coarse particles obtained can be returned to the kneading step and used for the formation of particles. At that time, fine particles or coarse particles may be wet. The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the classification operation described above.
The obtained powder after drying is mixed with at least a binder resin, a colorant and a release agent, and different types of particles such as a charge control agent and inorganic particles, using the above-mentioned flow stirring mixer, and mixed powder By applying a mechanical impact force to the body, it can be immobilized and fused on the surface, and detachment of foreign particles from the surface of the resulting composite particles can be prevented.

Here, each device in the image forming apparatus will be described.
(Fixing device)
FIG. 3 is a view showing a fixing device according to the present invention. The two-component developer can be used, for example, in an image forming apparatus having a fixing device as shown here.
Here, the fixing device is a so-called surf fixing device that rotates and fixes a fixing film as shown in FIG. More specifically, the fixing film 26 is an endless belt-like heat-resistant film, and is held by a driving roller 25c, a driven roller 25b, and a heater support 25e provided below the two rollers. The heating body 25a is fixedly supported by the heating body 25a.
The driven roller 25b also serves as a tension roller for the fixing film 26. The fixing film is driven to rotate in the clockwise direction by the rotation of the driving roller 25c in the clockwise direction in the drawing. The rotational drive speed is adjusted to a speed at which the transfer material P and the fixing film 26 have the same speed in the fixing nip region L where the pressure roller 27 and the fixing film are in contact.
Here, the pressure roller 27 is a roller having a rubber elastic layer having a good releasability such as silicon rubber, and the total pressure of 4 to 10 kg is applied to the fixing nip region L while rotating counterclockwise. It is pressed with contact pressure.

The fixing film 26 preferably has excellent heat resistance, releasability, and durability, and a thin film having a total thickness of 100 μm or less, preferably 40 μm or less is used. For example, at least an image of a single layer film or a composite layer film of a heat-resistant resin such as polyimide, polyetherimide, PES (polyether sulfide), PFA (tetrafluoroethylene barfluoroalkyl vinyl ether copolymer resin) or the like, for example, a 20 μm thick film The contact surface is coated with a release coating layer made of PTFE (tetrafluoroethylene resin), PFA or other fluororesin with a conductive material added to a thickness of 10 μm, or an elastic layer such as fluororubber or silicon rubber. It is what.
The heating body of the present embodiment includes a flat substrate 25e and a fixing heater 25a. The flat substrate 25e is made of a material having high thermal conductivity and high electrical resistivity such as alumina and is in contact with the fixing film 26. On the surface to be fixed, a fixing heater 25a made of a resistance heating element is provided in the longitudinal direction. The fixing heater 25a is formed by applying an electric resistance material such as Ag / Pd or T a ₂ N in a linear or belt shape by screen printing or the like. In addition, electrodes (not shown) are formed at both ends of the fixing heater 25a, and the resistance heating element generates heat when energized between the electrodes. Further, a fixing temperature sensor composed of a thermistor is provided on the surface of the substrate 25e opposite to the surface provided with the fixing heater 25a.
The substrate temperature information detected by the fixing temperature sensor 25d is sent to a control unit (not shown), and the amount of electric power supplied to the fixing heater 25a is controlled by the control unit, so that the heating body is controlled to a predetermined temperature.

(Amorphous silicon photoconductor)
As an electrophotographic photoreceptor used in an image forming apparatus using the two-component developer of the present invention, a conductive support is heated to 50 ° C. to 400 ° C., and a vacuum deposition method, a sputtering method, An amorphous silicon photoconductor (hereinafter referred to as “a-Si photoconductor”) having a photoconductive layer made of a-Si by a film forming method such as an ion plating method, a thermal CVD method, a photo CVD method, or a plasma CVD method. ) Can be used. Among them, a plasma CVD method, that is, a method in which a source gas is decomposed by direct current, high frequency or microwave glow discharge to form an a-Si deposited film on a support is preferably used.

(Layer structure)
The layer structure of the amorphous silicon photoconductor is, for example, as follows. FIG. 4 is a schematic configuration diagram for explaining the layer configuration of the amorphous silicon photoconductor. In the electrophotographic photoreceptor 500 shown in FIG. 4A, a photoconductive layer 502 made of a-Si: H, X and having photoconductivity is provided on a support 501. An electrophotographic photosensitive member 500 shown in FIG. 4B includes a photoconductive layer 502 made of a-Si: H, X and having photoconductivity, and an amorphous silicon surface layer 503 on a support 501. It is configured. An electrophotographic photoreceptor 500 shown in FIG. 4C has a photoconductive layer 502 made of a-Si: H, X and having photoconductivity on a support 501, an amorphous silicon-based surface layer 503, and And an amorphous silicon based charge injection blocking layer 504. In an electrophotographic photoreceptor 500 shown in FIG. 4D, a photoconductive layer 502 is provided on a support 501. The photoconductive layer 502 includes a charge generation layer 505 made of a-Si: H, X and a charge transport layer 506, and an amorphous silicon-based surface layer 503 is provided thereon.

(Support)
The support for the photoreceptor may be conductive or electrically insulating. Examples of the conductive support include metals such as Al, Cr, Mo, Au, In, Nb, Te, V, Ti, Pt, Pd, and Fe, and alloys thereof such as stainless steel. Also, at least the surface on the side where the photosensitive layer is to be formed of an electrically insulating support such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, polyamide or other synthetic resin film or sheet, glass or ceramic. A conductively treated support can also be used.
The shape of the support can be a cylindrical or plate-like or endless belt with a smooth or uneven surface, and the thickness thereof is appropriately determined so that a desired photoreceptor for an image forming apparatus can be formed. When flexibility as a photoreceptor for an image forming apparatus is required, it can be made as thin as possible within a range where the function as a support can be sufficiently exhibited. However, the support is usually 10 μm or more from the viewpoints of production and handling, mechanical strength, and the like.

(Injection prevention layer)
In the amorphous silicon photoconductor that can be used in the present invention, a charge injection blocking layer that functions to block charge injection from the conductive support side is provided between the conductive support and the photoconductive layer as necessary. It is more effective to provide this (FIG. 4C). That is, the charge injection blocking layer has a function of blocking charge injection from the support side to the photoconductive layer side when the photosensitive layer is subjected to a charging process with a certain polarity on its free surface. When charged, it has a so-called polarity dependency that does not exhibit such a function. In order to provide such a function, the charge injection blocking layer contains a relatively large number of atoms for controlling conductivity as compared with the photoconductive layer.
The layer thickness of the charge injection blocking layer is preferably from 0.1 to 5 μm, more preferably from 0.3 to 4 μm, and most preferably from 0.5 to 0.5 in view of obtaining desired electrophotographic characteristics and economic effects. It is desirable to be 3 μm.

(Photoconductive layer)
The photoconductive layer is formed on the undercoat layer as necessary, and the layer thickness of the photoconductive layer 502 is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects, preferably It is desirable that the thickness is 1 to 100 μm, more preferably 20 to 50 μm, and most preferably 23 to 45 μm.

(Charge transport layer)
The charge transport layer is a layer mainly having a function of transporting charges when the photoconductive layer is functionally separated. The charge transport layer includes at least silicon atoms, carbon atoms, and fluorine atoms as constituent elements, and is formed of a-SiC (H, F, O) including hydrogen atoms and oxygen atoms as required. It has conductive properties, particularly charge retention properties, charge generation properties, and charge transport properties. In the present invention, it is particularly preferable to contain an oxygen atom.
The layer thickness of the charge transport layer is appropriately determined as desired from the viewpoints of obtaining desired electrophotographic characteristics and economic effects. The charge transport layer is preferably 5 to 50 μm, more preferably 10 to 40 μm, Optimally, the thickness is desirably 20 to 30 μm.

(Charge generation layer)
The charge generation layer is a layer mainly having a function of generating charges when the photoconductive layer is functionally separated. This charge generation layer is composed of a-Si: H containing at least silicon atoms as components and substantially no carbon atoms and, if necessary, hydrogen atoms, and has desired photoconductive properties, particularly charge generation properties. , Has charge transport properties.
The layer thickness of the charge generation layer is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects, etc., preferably 0.5 to 15 μm, more preferably 1 to 10 μm, optimally 1 ˜5 μm.

(Surface layer)
If necessary, the amorphous silicon photoreceptor that can be used in the present invention can be provided with a surface layer on the photoconductive layer formed on the support as described above. It is preferable to form a surface layer. This surface layer has a free surface, and is provided to achieve the object of the present invention mainly in moisture resistance, continuous repeated use characteristics, electrical pressure resistance, use environment characteristics, and durability.
The thickness of the surface layer in the present invention is usually 0.01 to 3 μm, preferably 0.05 to 2 μm, and most preferably 0.1 to 1 μm. If the layer thickness is less than 0.01 μm, the surface layer is lost due to wear or the like during use of the photoreceptor, and if it exceeds 3 μm, electrophotographic characteristics such as an increase in residual potential are observed.

(Development means)
Here, in the developing device 61 of the present embodiment in the image forming apparatus, during development, a vibration bias voltage obtained by superimposing an AC voltage on a DC voltage is applied to the developing sleeve 61b as a developing bias by a power source (not shown). The The background portion potential and the image portion potential are located between the maximum value and the minimum value of the vibration bias potential. As a result, an alternating electric field whose direction changes alternately is formed in the developing portion. In this alternating electric field, the toner and carrier of the developer vibrate vigorously, and the toner flies off the photosensitive sleeve 40 by shaking off the electrostatic restraining force on the developing sleeve 61b and the carrier, corresponding to the latent image on the photosensitive drum 40. And adhere.
The difference (maximum peak voltage) between the maximum value and the minimum value of the vibration bias voltage is preferably 0.5 to 5 KV, and the frequency is preferably 1 to 10 KHz. As the waveform of the vibration bias voltage, a rectangular wave, a sine wave, a triangular wave, or the like can be used. As described above, the DC voltage component of the vibration bias is a value between the background part potential and the image part potential, but the value closer to the background part potential than the image part potential is more likely to cover the background part potential region. This is preferable for preventing toner adhesion.
When the waveform of the vibration bias voltage is a rectangular wave, the duty ratio is desirably 50% or less. Here, the duty ratio is a ratio of time during which the toner is directed to the photosensitive member during one cycle of the vibration bias. By doing so, the difference between the peak value at which the toner is directed to the photoconductor 40 and the time average value of the bias can be increased, so that the movement of the toner is further activated, so that the toner moves on the latent image surface. It can adhere to the potential distribution faithfully and improve the feeling of roughness and resolution. In addition, since the difference between the peak value of the carrier having a charge opposite to that of the toner and the time average value of the bias toward the photoconductor can be reduced, the movement of the carrier is calmed down, and the background portion of the latent image is reduced. The probability of carriers adhering to the substrate can be greatly reduced.

(Charging device)
As the charging device used in the image forming apparatus using the two-component developer of the present invention, the charging device shown in FIGS. 5A and 5B can be used.
(In case of roller charging)
FIG. 5 is a diagram showing a schematic configuration of a contact-type charging device according to the present invention. In FIG. 5A, a photosensitive member 40 as an image bearing member that is a charged member is a charging member that is driven to rotate at a predetermined speed (process speed) in the direction of an arrow and is in contact with the photosensitive drum 40. The charging roller 60a is basically composed of a core metal 60c and a conductive rubber layer 60d formed on the roller concentrically and integrally on the outer periphery of the core metal 60c. In addition to the holding, the photosensitive drum 40 is pressed with a predetermined pressing force by a pressing means (not shown). In the case of this figure, the charging roller 60 a rotates following the rotational driving of the photosensitive drum 40. To do. The charging roller 60a is formed to have a diameter of 16 mm by coating a medium resistance rubber layer 60d of about 100,000 Ω · cm on a core metal 60c having a diameter of 9 mm.
The metal core 60c of the charging roller 60a and the illustrated power source 60f are electrically connected, and a predetermined bias is applied to the charging roller 60a by the power source. As a result, the peripheral surface of the photoconductor 40 is uniformly charged to a predetermined polarity and potential.
The shape of the charging member used in the present invention may take any form such as a magnetic brush or a fur brush in addition to the roller, and can be selected according to the specifications and form of the electrophotographic apparatus. When the magnetic brush is used, the magnetic brush is made up of various ferrite particles such as Zn-Cu ferrite as a charging member, a nonmagnetic conductive sleeve for supporting the ferrite member, and a magnet roll included in the nonmagnetic conductive sleeve. In addition, when using a fur brush, for example, as a material of the fur brush, a fur treated with carbon, copper sulfide, metal, and metal oxide is used, and this is wound around a metal or other conductive core metal. By charging or pasting, it becomes a charger.

(Fur brush charging)
In FIG. 5B, a photoconductor 40 as an image carrier that is a member to be charged is driven to rotate at a predetermined speed (process speed) in the direction of an arrow, and is constituted by a fur brush as a charging member. 60b is brought into contact with a predetermined nip width with a predetermined pressing force against the elasticity of the brush portion 60e.
The fur brush roller 60b as a contact charging member in this example is made of a metal cored bar 60c having a diameter of 6 mm, which also serves as an electrode, and a conductive rayon fiber REC-B manufactured by Unitika Ltd. as a brush portion 60e. The tape is wound in a spiral shape to form a roll brush having an outer diameter of 14 mm and a longitudinal length of 250 mm. The brush 60e has a brush density of 300 denier / 50 filaments and a density of 155 per square millimeter. This roll brush was inserted into a pipe having an inner diameter of 12 mm while rotating in one direction, and the brush and the pipe were set to be concentric, and left in a high-temperature and high-humidity atmosphere to bend and bevel.
The resistance value of the fur brush roller is 1 × 10 5 Ω at an applied voltage of 100V. This resistance value was converted from the current that flows when a fur brush roller is brought into contact with a metal drum having a diameter of φ30 mm with a nip width of 3 mm and a voltage of 100 V is applied.
The resistance value of the fur brush charger is such that, even when a low-voltage defective portion such as a pinhole is generated on the photosensitive member 40 to be charged, an excessive leakage current flows into this portion, and the charging nip portion becomes poorly charged. 10 ⁴ Ω or more is required to prevent image defects, and 10 ⁷ Ω or less is required to sufficiently inject the charge onto the surface of the photoreceptor.
In addition to REC-B manufactured by Unitika Ltd., the brush material is REC-C, REC-M1, REC-M10, SA-7 manufactured by Toray Industries, Inc., Nippon Kashiwa Co., Ltd. It is possible to use Sanderlon manufactured by Kanebo, Beltron manufactured by Kanebo, Krakarabo manufactured by Kuraray Co., Ltd., carbon dispersed in rayon, and global manufactured by Mitsubishi Rayon Co., Ltd. One brush is 3 to 10 denier, and preferably has a density of 10 to 100 filaments / bundle and 80 to 600 brushes / mm. The hair foot is preferably 1 to 10 mm.
The fur brush roller is rotationally driven at a predetermined peripheral speed (surface speed) in the opposite direction (counter) to the rotation direction of the photoconductor 40 and contacts the surface of the photoconductor 40 with a speed difference. By applying a predetermined charging voltage from the power source to the fur brush roller, the surface of the rotary photoconductor 40 is uniformly contact-charged to a predetermined polarity and potential. In this example, contact charging of the photoreceptor 40 by the fur brush roller 60b is performed by direct injection charging, and the surface of the rotating photoreceptor is charged to a potential substantially equal to the charging voltage applied to the fur brush roller 60b. .
The shape of the charging member used in the present invention may take any form such as a charging roller and a fur brush in addition to the fur brush roller, and can be selected according to the specifications and form of the electrophotographic apparatus. When a charging roller is used, it is generally used by coating a medium resistance rubber layer of about 100,000 Ω · cm on a cored bar. When the magnetic brush is used, the magnetic brush is made up of various ferrite particles such as Zn-Cu ferrite as a charging member, a nonmagnetic conductive sleeve for supporting the ferrite member, and a magnet roll included in the nonmagnetic conductive sleeve.

(In case of magnetic brush charging)
FIG. 5B shows a schematic configuration of an example of an image forming apparatus using a contact-type charging device. A photosensitive member 40 as an image carrier, which is a member to be charged, is rotationally driven in the direction of the arrow at a predetermined speed (process speed). A brush roller 60b constituted by a magnetic brush is brought into contact with the photosensitive member with a predetermined nip width with a predetermined pressing force against the elasticity of the brush portion 60e.
As a magnetic brush as a contact charging member in this example, Zn—Cu ferrite particles having an average particle diameter of 25 μm and Zn—Cu ferrite particles having an average particle diameter of 10 μm are mixed at a weight ratio of 1: 0.05, Magnetic particles were used in which ferrite particles having an average particle diameter of 25 μm and having a peak at the position of each average particle diameter were coated with a medium resistance resin layer. The contact charging member is composed of the coated magnetic particles prepared above, a nonmagnetic conductive sleeve for supporting the coated magnetic particles, and a magnet roll included in the nonmagnetic conductive sleeve. Coating was performed at 1 mm to form a charging nip having a width of about 5 mm between the photosensitive member and the photosensitive member. The gap between the magnetic particle holding sleeve and the photosensitive member was about 500 μm. Furthermore, the magnet roll is rotated so that the sleeve surface slides in the opposite direction at twice the circumferential speed of the photosensitive member surface, and the photosensitive member and the magnetic brush are uniformly contacted. I did it.
The shape of the charging member used in the present invention may take any form such as a charging roller or a fur brush in addition to the magnetic brush, and can be selected according to the specifications and form of the electrophotographic apparatus. When a charging roller is used, it is generally used by coating a medium resistance rubber layer of about 100,000 Ω · cm on a cored bar. In addition, when using a fur brush, for example, as a material of the fur brush, a fur treated with carbon, copper sulfide, metal, and metal oxide is used, and this is wound around a metal or other conductive core metal. By charging or pasting, it becomes a charger.

  EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. Below, a part shows a weight part.

[Example 1]
<Production Example 1> (Synthesis of organic fine particle emulsion)
In a reaction vessel equipped with a stirrer and a thermometer, 683 parts of water, 11 parts of a sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30: manufactured by Sanyo Chemical Industries), 83 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate and 1 part of ammonium persulfate were charged and stirred for 15 minutes at 400 rpm, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion [fine particle dispersion 1] was obtained. The volume average particle size of the [fine particle dispersion 1] measured with a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba Seisakusho) was 0.10 μm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The resin content Tg was 57 ° C.

<Production Example 2> (Preparation of aqueous phase)
990 parts of water, 80 parts of [fine particle dispersion 1], 40 parts of 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7: Sanyo Chemical Industries) and 90 parts of ethyl acetate are mixed and stirred to give a milky white liquid. Got. This is designated as [Aqueous Phase 1].

<Production Example 3> (Synthesis of low molecular weight polyester)
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 220 parts of bisphenol A ethylene oxide 2-mole adduct, 561 parts of bisphenol A propylene oxide 3-mole adduct, 218 parts of terephthalic acid, 48 parts of adipic acid and dibutyl Add 2 parts of tin oxide and react for 8 hours at 230 ° C. under normal pressure, and further react for 5 hours under reduced pressure of 10 to 15 mmHg, and then add 45 parts of trimellitic anhydride to the reaction vessel and add 2 parts at 180 ° C. and normal pressure. The reaction was performed for a time to obtain [Low molecular weight polyester 1]. [Low molecular polyester 1] had a number average molecular weight of 2500, a weight average molecular weight of 6700, Tg of 47 ° C., and an acid value of 25.

<Production Example 4> (Prepolymer synthesis)
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen introduction tube, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride, and 2 parts of dibutyltin oxide was added and reacted at 230 ° C. under normal pressure for 8 hours, and further reacted at reduced pressure of 10 to 15 mmHg for 5 hours to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5, and a hydroxyl value of 49.
Next, 411 parts of [Intermediate polyester 1], 89 parts of isophorone diisocyanate and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Polymer 1] was obtained. [Prepolymer 1] had a free isocyanate weight% of 1.53%.

<Production Example 5> (Synthesis of ketimine)
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 418.

<Production Example 6> (Synthesis of master batch)
40 parts of carbon black (Regal 400R: manufactured by Cabot), binder resin: 60 parts of polyester resin (Sanyo Kasei RS-801, acid value 10, Mw 20000, Tg 64 ° C.), and 30 parts of water are mixed in a Henschel mixer, and pigment aggregation is mixed. A mixture soaked with water in the aggregate was obtained. This was kneaded for 45 minutes with two rolls set at a roll surface temperature of 130 ° C., and pulverized to a size of 1 mmφ with a pulverizer to obtain [Masterbatch 1].

<Production Example 7> (Preparation of oil phase)
After charging 378 parts of [low molecular weight polyester 1], 110 parts of carnauba wax, and 947 parts of ethyl acetate in a container equipped with a stir bar and a thermometer, the temperature was raised to 80 ° C. with stirring, and maintained at 80 ° C. for 5 hours. Cooled to 30 ° C. in 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were placed in a container and mixed for 1 hour to obtain [Raw material solution 1].
[Raw material solution 1] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. Carbon black and wax were dispersed under conditions of filling and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester 1] was added, and one pass was performed with a bead mill under the above conditions to obtain [Pigment / Wax Dispersion 1]. The solid content concentration of [Pigment / Wax Dispersion 1] (130 ° C., 30 minutes) was 50%.

<Production Example 8> (Emulsification)
[Pigment / WAX Dispersion 1] 648 parts, [Prepolymer 1] 154 parts, [Ketimine Compound 1] 6.6 parts in a container, TK homomixer (manufactured by Tokushu Kika) at 5,000 rpm for 1 minute After mixing, 1200 parts of [Aqueous Phase 1] was added to the container, and mixed with a TK homomixer at 13,000 rpm for 20 minutes to obtain [Emulsified Slurry 1].

<Production Example 9> (Modification)
1365 parts of ion-exchanged water, 35 parts of carboxymethyl cellulose (CMC Daicel-128: manufactured by Daicel Chemical Industries, Ltd.), and 1000 parts of [Emulsified slurry 1] were mixed in the stirred aqueous solution, and TK homomixer (special machine) The mixture was mixed at 2,000 rpm for 1 hour to obtain [Deformed slurry 1].

<Production Example 10> (solvent removal)
[Deformed slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C for 8 hours, aging was performed at 45 ° C for 4 hours to obtain [Dispersed slurry 1].

<Production Example 11> (washing => drying)
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(2): 100 parts of 10% sodium hydroxide aqueous solution was added to the filter cake of (1), ultrasonic vibration was applied and mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure. . This ultrasonic alkali cleaning was performed again (two ultrasonic alkali cleanings).
(3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(4): Add 300 parts of ion-exchanged water to the filter cake of (3), mix with a TK homomixer (10 minutes at 12,000 rpm) and then filter twice to obtain [Filter cake 1]. It was. [Filtration cake 1] was dried at 45 ° C. for 48 hours with a circulating drier, and sieved with a mesh having an opening of 75 μm, whereby toner base 1 was obtained.
Next, 100 parts of toner base 1 and 0.3 part of a charge control agent (Orient Chemical Co., Ltd., Bontron E-84) were charged into a Q-type mixer (Mitsui Mining Co., Ltd.), and the peripheral speed of the turbine blades was 50 m / sec. And mixed. In this case, the mixing operation was performed for 2 minutes, 5 cycles of 1 minute pause, and the total treatment time was 10 minutes.
Further, 0.5 part of hydrophobic silica (H2000, manufactured by Clariant Japan) was added and mixed. In this case, the mixing operation was performed at a peripheral speed of 15 m / sec, and 30 seconds of mixing and rest for 1 minute were performed for 5 cycles to obtain toner 1. Table 1 shows the volume average particle size, 3 μm or less fine powder content, and average circularity.

[Examples 2 to 8, Comparative Examples 1 to 6]
In [Example 1], the number of revolutions / time of the TK homomixer in the emulsification step, the amount of thickener in the deforming step, the number of revolutions / time of the TK homomixer, and the temperature / time in the desolvation step are sequentially determined. As a result, toners 2 to 14 having different volume average particle sizes, 3 μm or less fine powder content, and average circularity as shown in Table 1 were obtained.

An example of the production of a carrier for blending with the toners of Examples and Comparative Examples obtained above to produce a two-component developer is shown below.
<Example of carrier production>
Silicone resin (organostraight silicone): 100 parts Toluene: 100 parts γ- (2-Aminoethyl) aminopropyltrimethoxysilane: 5 parts Carbon black: 10 parts The above mixture is dispersed with a homomixer for 20 minutes to form a coating layer forming solution. Was prepared.
This coating layer forming liquid was coated on the surface of 1000 parts of spherical magnetite having a particle diameter of 50 μm using a fluid bed type coating apparatus to obtain a magnetic carrier.
96 parts of the magnetic carrier were mixed with 4 parts of the toner by a ball mill to prepare a two-component developer, and the following evaluation was performed. The evaluation results are shown in Table 1.

[Evaluation item]
(Skin dirt, image density evaluation)
96 parts of the magnetic carrier were mixed with 4 parts of the toner by a ball mill to prepare a two-component developer, and the following evaluation was performed. The evaluation results are shown in Table 1.
In this evaluation, the developer is used in a copying machine imagio Neo 451 manufactured by Ricoh Co., Ltd., which has a cleaning blade and a charging roller in contact with the photosensitive member, and has a mechanism for collecting and recycling untransferred toner in a cleaning unit. Then, after 100,000 copies of the A4 horizontal chart (image pattern A) in which the black solid and the white solid are repeated at intervals of 1 cm in the direction perpendicular to the rotation direction of the developing sleeve, a predetermined image shown below is output, Image evaluation was performed using the following criteria.

(Skin dirt)
The blank image was stopped during development, the developer on the developed photoreceptor was tape transferred, and the difference from the image density of the untransferred tape was measured with a 938 spectrocytometer (X-Rite). When the image density difference is ID: 0.01 or less, ●, ID: 0.01 to 0.02, ○, ID: 0.02 to 0.03, Δ, ID: 0.03 or more Things were evaluated as x. FIG. 6 is a plot diagram showing the relationship between the overall background stain evaluation in Table 1, the content of fine powder of 3 μm or less and the average circularity of the replenishment toner.
(Image density evaluation)
One black solid checker image of 1 cm × 1 cm on the side of A4 was output, and the image density was measured by X-Rite (manufactured by X-Rite). This was measured at five points to determine the average. The case where the image density was good was evaluated as ◯, the case where the image density was not good but acceptable was evaluated as Δ, and the case where the image density was poor was evaluated as x.

1 is a schematic configuration diagram of a tandem color image forming apparatus according to the present invention. 1 is a schematic cross-sectional view showing a schematic configuration of a developing device of the present invention. 1 is a diagram illustrating a fixing device according to the present invention. It is a typical block diagram for demonstrating the layer structure of an amorphous silicon photoconductor. 1 is a diagram illustrating a schematic configuration of an example of an image forming apparatus using a contact-type charging device according to the present invention. FIG. 2 is a plot diagram showing the relationship between the overall background stain evaluation in Table 1, the content of fine powder of 3 μm or less and the average circularity of the replenishment toner.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Intermediate transfer body 14, 15, 16 Support roller 17 Intermediate transfer body cleaning apparatus 18 Image forming means 20 Tandem image forming part 21 Exposure apparatus 22 Secondary transfer apparatus (transfer roller)
23 roller 24 secondary transfer belt 25 fixing device 25a fixing heater 25b driven roller 25c driving roller 25d fixing temperature sensor 25e flat substrate 26 fixing belt (fixing film)
27 Pressure roller 28 Sheet reversing device 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging lens 36 Reading sensor 40 Photoconductor 41 Developing belt 42 Paper feed roller 43 Paper bank 44 Paper feed cassette 45 Separating roller 46, 48 Feeding path 47 Conveying roller 49 Registration roller 50 Feeding roller 51 Manual feed tray 52 Separating roller 53 Manual feeding path 55 Switching claw 56 Ejection roller 57 Ejection tray 60 Charging device 60a Charging roller 60b Brush roller 60c Core metal 60d Conductive rubber Layer 60e Brush portion 60f Power supply 61 Developing device 61b Developing sleeve 62 Primary transfer device 63 Cleaning device 64 Static eliminating device (static eliminating lamp)
DESCRIPTION OF SYMBOLS 100 Copier main body 200 Paper feed table 300 Scanner 400 Automatic document feeder P Transfer material

Claims (14)

A toner used in a two-component developer containing a silicone coat carrier and a toner,
At least a binder resin, to obtain a toner base by removing the solvent from the emulsified dispersion obtained by dispersing a colorant and a releasing agent as oil droplets in the solvent, the toner base, the charging control agent and a non-fine particles in preparative toner obtained by externally added,
When the toner is replenished, the average circularity measured by a flow type particle image analyzer is 0.930 to 0.965, and the fine powder content is 3 to 20% by number. ,
The toner in the developing device after replenishment has a fine powder content of 3 μm or less of 5 to 70% by number. The electrostatic image developing toner according to claim 1,
The toner according to claim 1, wherein the charge control agent is added in an amount of 0.2 to 1.0% by weight based on the toner base. In the electrostatic image developing toner according to claim 1 or 2,
The toner for developing an electrostatic charge image, wherein the inorganic fine particles are silica and / or titanium. The electrostatic image developing toner according to any one of claims 1 to 3,
The toner base dissolves or disperses a composition containing a compound having an active hydrogen group, a colorant, and a release agent in at least an organic solvent, and disperses the composition solution or dispersion in an aqueous medium. For developing an electrostatic image, characterized by being obtained by reacting a compound having an active hydrogen group with a resin capable of reacting or reacting with a resin, removing the organic solvent, washing and drying. toner. The electrostatic charge image developing toner according to claim 1,
The electrostatic charge image developing toner, wherein the toner base has a ratio Dv / Dn of volume average particle diameter Dv to number average particle diameter Dn of 1.25 or less. A developer for developing an electrostatic latent image formed on a latent image carrier,
The developer is a two-component developer containing a silicone coat carrier and a toner,
The developer according to claim 1, wherein the toner is a toner according to claim 1. The developer according to claim 6,
The silicone-coated carrier has a coating layer containing at least a silicone resin and / or carbon, has a weight average particle size of 45 to 65 μm, and the content of carrier particles having a particle size of less than 37 μm is 0 to 15 wt. % Developer. A step of forming an electrostatic latent image on the image carrier, a step of developing the electrostatic latent image with a developer containing a toner for developing an electrostatic image, and forming a toner image; In an image forming method including a step of transferring, and a step of fixing a toner image on a transfer target,
The image forming method according to claim 6, wherein the developing step uses the developer according to claim 6. A latent image carrier that carries at least a latent image, a charging device having a charging member that uniformly charges the surface of the image carrier, an exposure device that writes an electrostatic latent image on the surface of the charged image carrier, and an image carrier A developing device that visualizes the electrostatic latent image formed on the surface with toner on the developer carrier, and the toner image visualized on the image carrier is transferred to a recording medium directly or via an intermediate transfer member An image forming apparatus comprising: a transfer device that fixes the toner image on the recording medium with heat and / or pressure.
The image forming apparatus is filled with the developer according to claim 6. The image forming apparatus according to claim 9.
The image forming apparatus, wherein the latent image carrier is an amorphous silicon photoconductor. The image forming apparatus according to claim 9 or 10, wherein:
The image forming apparatus applies an alternating voltage when developing the latent image on the latent image carrier. The image forming apparatus according to any one of claims 9 to 11,
The fixing device includes a heating body including a heating element, a film that comes into contact with the heating body, and a pressure member that is in pressure contact with the heating body via the film. An image forming apparatus comprising: a fixing device that heats and fixes a recording material on which an unfixed image is formed. The image forming apparatus according to any one of claims 9 to 12,
The image forming apparatus, wherein the charging device is a charging device that performs charging by bringing a charging member into contact with the latent image carrier and applying a voltage to the charging member. In a process cartridge that integrally supports at least an image carrier and at least one unit selected from a charging unit, a developing unit, and a cleaning unit, and is detachable from the image forming apparatus main body.
The process cartridge holds the developer according to claim 6 or 7. A process cartridge.

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