JP2016040586A - Developing device, image forming apparatus, developing method, image forming method, and developer set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device that suppresses the occurrence of a phenomenon where a toner is adhered to a non-image part (fogging) that occurs after low-density images are repeatedly output.SOLUTION: There is provided a developing device including: a developing part that stores a first developer containing a first negatively-charged toner and a carrier, and develops an electrostatic latent image formed on an image holding body with the first developer to form a toner image; and a developer supply part that stores a second developer containing a second negatively-charged toner having a triboelectric series located on a positive electrode side compared with that of the first negatively-charged toner, and supplies the second developer to the developing part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a developing device, an image forming apparatus, a developing method, an image forming method, and a developer set.

The electrophotographic method is widely used for copying machines, printers, and the like.
For example, Japanese Patent Application Laid-Open No. 2003-228867 describes that “a toner replenishing unit for newly replenishing toner in the apparatus is provided, and the toner replenishing unit is disposed in the apparatus over time as compared with the particle size of the initial replenishment toner that is initially replenished in the apparatus. A developing device is disclosed that replenishes toners having different particle sizes so that the particle size of replenished toner with time is small.

  Further, Patent Document 2 states that “a replenishing means for replenishing toner to the developing device, a developer carrying member included in the developing device, and a deteriorated toner in the developing device are mixed with the replenished toner. An image forming apparatus comprising: a holding unit that electrically sucks and holds the reversely charged toner that is generated and adsorbed to the developer carrying member; and a collecting unit that collects the reversely charged toner from the holding unit is disclosed. Has been.

  Patent Document 3 states that “a forced discharge image forming area is provided in a non-image forming area other than the image forming area on the photoconductor, and a forced discharge toner image is formed in the forced discharge image forming area. A toner forced discharge mode for forcibly discharging toner from the developing device, and in the toner forced discharge mode, an AC bias having a frequency lower than that of the image forming region is applied to the forced discharging image forming region to An image forming apparatus is disclosed in which an image is developed to form a forced discharge toner image and the toner is collected by the cleaning device.

  Patent Document 4 states that “a region other than a region where an image is to be formed on a photoconductor is charged, and this charged region is set to have a potential at which fogging occurs when developing. A “toner removing device that removes toner from the developing device” is disclosed.

JP 2007-163592 A JP 2011-170104 A JP 2006-3313307 A Japanese Patent Laid-Open No. 3-91782

  An object of the present invention is to provide a developing device that suppresses the occurrence of a phenomenon in which toner adheres to a non-image portion (hereinafter also referred to as “fogging”) that occurs when a low-density image is repeatedly output.

  The above problem is solved by the following means.

The invention according to claim 1
Development that contains a first developer containing a first negatively chargeable toner and a carrier, and that develops the electrostatic latent image formed on the image carrier with the first developer to form a toner image. And
Development in which a second developer containing a second negatively chargeable toner whose charged column is located on the positive electrode side of the first negatively chargeable toner is contained, and the second developer is supplied to the developing unit. An agent replenishment section;
A developing device comprising:

The invention according to claim 2
2. The system according to claim 1, wherein when the standard charging ability of the first negatively chargeable toner is EC _A and the standard charging ability of the second negatively chargeable toner is EC _B , the following relational expression (1) is satisfied. Development device.
Relational expression (1): 5 ≦ EC _A −EC _B ≦ 30

The invention according to claim 3
Standard charging ability of said first negative chargeable toner and EC _A, the standard charging capacity of the second negative chargeable toner and EC _B, when the standard charging ability of the carrier to the EC _C, following relationships The developing device according to claim 1 or 2, which satisfies (2).
Relational expression (2): 0.3 ≦ | EC _A −EC _B | / | EC _C −EC _B | ≦ 1.0

The invention according to claim 4
An image carrier,
A charging device for charging the surface of the image carrier;
A latent image forming apparatus for forming an electrostatic latent image on the surface of the charged image carrier;
4. A developing device that develops the electrostatic latent image formed on the image holding member with a developer to form a toner image, and the developing device according to claim 1. ,
A transfer device for transferring the toner image formed on the image carrier to a recording medium;
An image forming apparatus comprising:

The invention according to claim 5
A developing step of developing the electrostatic latent image formed on the image holding member with a first developer containing a first negatively chargeable toner and a carrier to form a toner image;
A replenishment step of replenishing the first developer with a second developer containing a second negatively chargeable toner having a charged column located on the positive electrode side of the first negatively chargeable toner;
A development method comprising:

The invention according to claim 6
A charging step for charging the surface of the image carrier;
A latent image forming step of forming an electrostatic latent image on the surface of the charged image carrier;
A developing step of developing the electrostatic latent image formed on the image holding member with a first developer including a first negatively chargeable toner and a carrier to form a toner image;
A transfer step of transferring the toner image formed on the image carrier to a recording medium;
A replenishment step of replenishing the first developer with a second developer containing a second negatively chargeable toner having a charged column located on the positive electrode side of the first negatively chargeable toner;
An image forming method comprising:

The invention according to claim 7 provides:
A first developer that is accommodated in a developing unit of a developing device that develops an electrostatic latent image formed on an image carrier with a first developer to form a toner image, and the first negatively charged A first developer containing a functional toner and a carrier;
A second developer housed in a developer replenishing portion of a developing device that replenishes the developing portion with a second developer, wherein a charged column is located on the positive electrode side of the first negatively chargeable toner. A second developer containing a second negatively chargeable toner;
A developer set.

According to the first aspect of the present invention, compared to the case where the first negatively chargeable toner and the second negatively chargeable toner have the same charge train, the fog generated when a low-density image is repeatedly output. A developing device that suppresses the occurrence is provided.
According to the second aspect of the present invention, there is provided a developing device that suppresses the occurrence of fogging that occurs when a low-density image is repeatedly output as compared with the case where Expression (1) is not satisfied.
According to the third aspect of the present invention, there is provided a developing device that suppresses the occurrence of fog, which occurs when a low-density image is repeatedly output, as compared with the case where Expression (2) is not satisfied.

  According to the invention of claim 4, 5, 6, or 7, the low-density image is repeatedly output as compared with the case where the charge columns of the first negatively chargeable toner and the second negatively chargeable toner are the same. There is provided an image forming apparatus, a developing method, an image forming method, or a developer set that suppresses the occurrence of fogging.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows the process cartridge which concerns on this embodiment.

  Embodiments that are examples of the present invention will be described below.

An image forming apparatus according to the present embodiment includes an image carrier, a charging device that charges the surface of the image carrier, a latent image forming device that forms an electrostatic latent image on the surface of the charged image carrier, and development. The image forming apparatus includes a developing device that develops the electrostatic latent image formed on the image holding member with an agent to form a toner image, and a transfer device that transfers the toner image formed on the image holding member to a recording medium.
The developing device (the developing device according to this embodiment) includes a first negatively chargeable toner (hereinafter also referred to as “accommodating toner”) and a carrier (hereinafter also referred to as “accommodating carrier”). A developing unit that contains a developer (hereinafter also referred to as “accommodating developer”), develops the electrostatic latent image formed on the image carrier with the accommodated developer, and forms a toner image; A replenishment developer containing a second developer (hereinafter also referred to as “replenishment developer”) containing a second negatively chargeable toner (hereinafter also referred to as “replenishment toner”) in which the charge column is located on the positive electrode side. A developer replenishing unit that replenishes the developing unit.

In the image forming apparatus according to the present embodiment, a charging step for charging the surface of the image holding member, a latent image forming step for forming an electrostatic latent image on the surface of the charged image holding member, and a storage toner and a carrier. A developing step of developing the electrostatic latent image formed on the image carrier with the containing developer to form a toner image; a transfer step of transferring the toner image formed on the image carrier to a recording medium; An image forming method (an image forming method according to the present embodiment) is provided that includes a replenishment step of replenishing the developer with a replenishment developer containing replenishment toner.
In other words, in the developing device (the developing device according to the present embodiment), a developing process in which the electrostatic latent image formed on the image holding member is developed with the stored developer including the stored toner and the stored carrier to form a toner image. And a replenishment step of replenishing the stored developer with a replenishment developer containing replenishment toner.

  With the above configuration, the developing device according to the present embodiment and the image forming apparatus including the same have fog (toner in a non-image portion) that is generated when a low-density image (for example, an image density of 3% or less) is repeatedly output. The phenomenon of the adhesion). The reason is not clear, but is presumed to be as follows.

  First, when an image having a low image density is repeatedly output, the stored toner contained in the stored developer stays in the developing unit of the developing device without being consumed. The staying stored toner is subjected to a mechanical load due to stirring or the like, so that the deterioration proceeds and the charge amount is reduced. When the charge amount of the stored toner is reduced, fog is likely to occur.

  On the other hand, when a replenishment developer including a replenishment toner in which a charged column is located on the positive electrode side with respect to the stored toner is supplied from the developer replenishment unit of the developing device to the developing unit, The toners come into contact with each other and are agitated to cause mutual charging between the two toners. At this time, the charge amount of the stored toner whose charge column is located on the negative electrode side with respect to the stored toner is raised. For this reason, even if it receives a mechanical load, the fall of the charge amount of the accommodation toner is suppressed.

  From the above, it is presumed that the developing device according to the present embodiment and the image forming apparatus including the same suppress the occurrence of fog that occurs when a low-density image is repeatedly output.

  Here, when the stored toner is deteriorated and the charge amount is decreased, density fluctuation occurs between the image before the deterioration of the stored toner and the image after the deterioration. Further, since the transferability of fogging and deteriorated toner due to low-charged toner is reduced, the amount of toner contained increases. On the other hand, in the developing device according to the present embodiment and the image forming apparatus including the same, since the decrease in the charge amount of the stored toner is suppressed, the image density fluctuation and the increase in the stored toner consumption amount are also increased. It is suppressed.

  Conventionally, for example, Japanese Patent Laid-Open No. 3-91782 proposes a toner removing device that removes deteriorated toner from the developing device. Japanese Patent Application Laid-Open No. 2006-313307 proposes an image forming apparatus that selectively discharges small-diameter toner having a reduced charge amount. However, any of these techniques only removes or discharges the deteriorated toner having a low charge, and has not yet solved the suppression of the decrease in the charge amount of the toner.

In the developing device according to the present embodiment and the image forming apparatus including the developing device, the replenishment toner charging column is positioned on the positive electrode side with respect to the stored toner. In other words, it is preferable to lower the property of charging the negative electrode of the replenishment toner than the accommodation toner. Also, if the difference between the charged toner and the replenishment toner is less than 5, the toners are less likely to be charged with each other. On the other hand, if the difference between the charge rows of the two toners exceeds 30, the replenishment of the replenishing toner may occur when the two toners are mutually charged.
Therefore, from the viewpoint of suppressing the occurrence of fogging, it is preferable that the following relational expression (1) is satisfied when the standard charging ability of the stored toner is EC _A and the standard charging ability of the replenishing toner is EC _B. It is more preferable to satisfy | fill Formula (1-2), and it is still more preferable to satisfy | fill the following (1-3). Here, the standard charging ability of the toner is the standard charging ability of the whole toner including the external additive when the external additive is included.
Relational expression (1): 5 ≦ EC _A −EC _B ≦ 30
-Relational expression (1-2): 5 ≦ EC _A −EC _B ≦ 20
Relational expression (1-3): 7 ≦ EC _A −EC _B ≦ 15

Further, if the difference between the charge trains of the storage toner and the replenishment toner is too small than the difference between the charge trains of the storage carrier and the replenishment toner, mutual charging of both toners is difficult to occur. On the other hand, if the difference between the charge trains of the storage toner and the replenishment toner is larger than the difference between the charge trains of the storage carrier and the replenishment toner, the reversal of the replenishment toner occurs when the toners are mutually charged. Sometimes.
Therefore, from the point of suppressing the occurrence of fog, the standard charging capacity of the stored toner to the EC _A, when the standard charging capacity of the supplied toner and EC _B, the standard charging capacity of accommodating the carrier was EC _C, following relationships It is preferable to satisfy (2), more preferably the following relational expression (2-2) is satisfied, and further preferably the following relational expression (2-3) is satisfied.
Relational expression (2): 0.3 ≦ | EC _A −EC _B | / | EC _C −EC _B | ≦ 1.0
Relational expression (2-2): 0.4 ≦ | EC _A −EC _B | / | EC _C −EC _B | ≦ 0.7
Relational expression (2-3): 0.4 ≦ | EC _A −EC _B | / | EC _C −EC _B | ≦ 0.6

The standard chargeability of the toner is a value measured by a method based on the standard method for measuring the charge amount of toner of the Japanese Imaging Society using four types of standard carriers distributed by the Technical Committee of the Imaging Society of Japan. Specifically, it is as follows.
Two types of carriers, P-01 and P-02, in which a fluorine-based resin is combined and coated with a resin as a positively chargeable toner carrier are set, and an acrylic resin-coated N- 01, N-02 types of carriers were set. Using each of the four types of carriers, the toner charge amount was measured at a toner concentration of 5%, and using the zero point charge method, the value on the Y-axis when X = 0 was used as the toner charge train (standard charge capacity) ).

The standard charging ability of the carrier is a value measured by the following method.
Two types of negatively charged toners and two types of positively charged toners with different toner charge amounts were set. Using the four types of toner, the zero point charge method is used in the same way as the toner chargeability calculation method, and the value on the Y-axis when X = 0 is used as the carrier charge train (standard chargeability). Stipulated.

  In addition, adjustment of the charge train (that is, standard charging ability) of each toner is, for example, 1) a method of adjusting by the resin type of toner particles, 2) a method of adjusting by the resin composition of toner particles, 3) external additive composition, It is performed by a method of adjusting according to the amount added.

  Here, the image forming apparatus according to the present embodiment includes a fixing device that fixes the toner image transferred on the surface of the recording medium; the toner image formed on the surface of the electrophotographic photosensitive member is directly transferred to the recording medium. Direct transfer system device; primary transfer of the toner image formed on the surface of the electrophotographic photosensitive member to the surface of the intermediate transfer member, and secondary transfer of the toner image transferred to the surface of the intermediate transfer member to the surface of the recording medium An intermediate transfer system device; a device equipped with a cleaning device for cleaning the surface of an electrophotographic photosensitive member after transfer of a toner image and before charging; A known image forming apparatus such as an apparatus provided with a static eliminator for removing electricity by irradiation; an apparatus provided with an electrophotographic photosensitive member heating member for increasing the temperature of the electrophotographic photosensitive member and reducing the relative temperature is applied.

  In the case of an intermediate transfer type device, the transfer device includes, for example, an intermediate transfer body on which a toner image is transferred to the surface, and a primary transfer that primarily transfers the toner image formed on the surface of the image carrier to the surface of the intermediate transfer body A configuration including an apparatus and a secondary transfer apparatus that secondary-transfers the toner image transferred onto the surface of the intermediate transfer member onto the surface of the recording medium is applied.

  Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. The main parts shown in the figure will be described, and the description of the other parts will be omitted.

  FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to the present embodiment. In the image forming apparatus shown in FIG. 1, the developing device corresponds to the developing unit, and the toner cartridge corresponds to the developer replenishing unit.

  The image forming apparatus shown in FIG. 1 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter sometimes simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged in parallel at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the image forming apparatus.

Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is provided by being wound around a drive roll 22 and a support roll 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are spaced apart from each other in the left to right direction in the drawing. The vehicle travels in the direction toward the unit 10K. The support roll 24 is applied with a force in a direction away from the drive roll 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound around the support roll 24. An intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the drive roll 22.
Further, each of the developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K has yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. The toner including the four color toners is supplied.

  Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, here, the first unit that forms a yellow image disposed on the upstream side in the intermediate transfer belt traveling direction. 10Y will be described as a representative. It should be noted that reference numerals with magenta (M), cyan (C), and black (K) are attached to the same parts as those of the first unit 10Y instead of yellow (Y). Description of the units 10M, 10C, and 10K will be omitted.

The first unit 10Y includes a photoreceptor 1Y that functions as an image holding member. Around the photoreceptor 1Y, a charging roll (an example of a charging unit) 2Y for charging the surface of the photoreceptor 1Y to a predetermined potential, and the charged surface is exposed by a laser beam 3Y based on a color-separated image signal. Then, an exposure device (an example of an electrostatic image forming unit) 3 that forms an electrostatic image, and a developing device (an example of a developing unit) 4Y that develops the electrostatic image by supplying toner charged to the electrostatic image, developed A primary transfer roll 5Y (an example of a primary transfer unit) that transfers a toner image onto the intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning unit) 6Y that removes toner remaining on the surface of the photoconductor 1Y after the primary transfer. Are arranged in order.
The primary transfer roll 5Y is disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoreceptor 1Y. Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K. Each bias power source varies the transfer bias applied to each primary transfer roll under the control of a control unit (not shown).

Hereinafter, an operation of forming a yellow image in the first unit 10Y will be described.
First, prior to operation, the surface of the photoreceptor 1Y is charged to a potential of −600V to −800V by the charging roll 2Y.
The photoreceptor 1Y is formed by laminating a photosensitive layer on a conductive substrate (for example, volume resistivity at 20 ° C .: 1 × 10 ⁻⁶ Ωcm or less). This photosensitive layer usually has a high resistance (general resin resistance), but has a property that the specific resistance of the portion irradiated with the laser beam changes when irradiated with the laser beam 3Y. Therefore, a laser beam 3Y is output to the surface of the charged photoreceptor 1Y via the exposure device 3 in accordance with yellow image data sent from a control unit (not shown). The laser beam 3Y is applied to the photosensitive layer on the surface of the photoreceptor 1Y, whereby an electrostatic charge image having a yellow image pattern is formed on the surface of the photoreceptor 1Y.

The electrostatic charge image is an image formed on the surface of the photoreceptor 1Y by charging, and the specific resistance of the irradiated portion of the photosensitive layer is lowered by the laser beam 3Y, and the charged charge on the surface of the photoreceptor 1Y flows. On the other hand, this is a so-called negative latent image formed by the charge remaining in the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoreceptor 1Y is rotated to a predetermined development position as the photoreceptor 1Y travels. At this development position, the electrostatic charge image on the photoreceptor 1Y is visualized (developed image) as a toner image by the developing device 4Y.

  In the developing device 4Y, for example, an electrostatic charge image developer containing at least yellow toner and a carrier is accommodated. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, has a charge of the same polarity (negative polarity) as the charged electric charge on the photoreceptor 1Y, and has a developer roll (of the developer holder). Example) is held on. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner is electrostatically attached to the latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. . The photoreceptor 1Y on which the yellow toner image is formed continues to run at a predetermined speed, and the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoreceptor 1Y is conveyed to the primary transfer, a primary transfer bias is applied to the primary transfer roll 5Y, and an electrostatic force from the photoreceptor 1Y toward the primary transfer roll 5Y is applied to the toner image, so that the photoreceptor is exposed. The toner image on 1Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time has a (+) polarity opposite to the polarity (−) of the toner, and is controlled to +10 μA by the control unit (not shown) in the first unit 10Y, for example.
On the other hand, the toner remaining on the photoreceptor 1Y is removed and collected by the photoreceptor cleaning device 6Y.

Further, the primary transfer bias applied to the primary transfer rolls 5M, 5C, and 5K after the second unit 10M is also controlled in accordance with the first unit.
Thus, the intermediate transfer belt 20 onto which the yellow toner image has been transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of the respective colors are superimposed and transferred in a multiple manner. The

  The intermediate transfer belt 20 on which the four color toner images are transferred in multiple ways through the first to fourth units is disposed on the image transfer surface side of the intermediate transfer belt 20, the support roll 24 in contact with the inner surface of the intermediate transfer belt 20. The secondary transfer roll (an example of a secondary transfer unit) 26 is formed to a secondary transfer portion configured. On the other hand, recording paper (an example of a recording medium) P is fed at a predetermined timing into a gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact with each other via a supply mechanism, and the secondary transfer bias is supplied to the support roll. 24. The transfer bias applied at this time is a (−) polarity that is the same polarity as the polarity (−) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, so The toner image is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by a resistance detection means (not shown) for detecting the resistance of the secondary transfer portion, and is voltage-controlled.

  Thereafter, the recording paper P is fed into the pressure contact portions (nip portions) of a pair of fixing rolls in a fixing device (an example of a fixing unit) 28, and the toner image is fixed on the recording paper P to form a fixed image.

Examples of the recording paper P to which the toner image is transferred include plain paper used in electrophotographic copying machines, printers, and the like. In addition to the recording paper P, the recording medium may be an OHP sheet.
In order to further improve the smoothness of the image surface after fixing, the surface of the recording paper P is also preferably smooth. For example, coated paper with the surface of plain paper coated with resin, art paper for printing, etc. are preferably used. Is done.

  The recording paper P on which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.

<Process cartridge / toner cartridge>
The process cartridge according to this embodiment will be described.
The process cartridge according to the present exemplary embodiment includes a developing unit that stores an electrostatic charge image developer, and develops the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer. It is a process cartridge that is detachable from the apparatus.

  Note that the process cartridge according to the present embodiment is not limited to the above-described configuration, and other means such as a developing device and other units such as an image carrier, a charging unit, an electrostatic charge image forming unit, and a transfer unit, if necessary. And at least one selected from the above.

  Hereinafter, an example of the process cartridge according to the present embodiment will be shown, but the present invention is not limited to this. The main parts shown in the figure will be described, and the description of the other parts will be omitted.

FIG. 2 is a schematic configuration diagram showing a process cartridge according to the present embodiment.
The process cartridge 200 shown in FIG. 2 is provided around the photoconductor 107 and the photoconductor 107 by, for example, a housing 117 provided with an attachment rail 116 and an opening 118 for exposure. A charging roller 108 (an example of a charging unit), a developing device 111 (an example of a developing unit), and a photoconductor cleaning device 113 (an example of a cleaning unit) are integrally combined and held to form a cartridge. Yes.
In FIG. 2, 109 is an exposure device (an example of an electrostatic charge image forming unit), 112 is a transfer device (an example of a transfer unit), 115 is a fixing device (an example of a fixing unit), and 300 is a recording paper (a recording medium). An example).

Next, the toner cartridge according to this embodiment will be described.
The toner cartridge according to the present exemplary embodiment is a toner cartridge that accommodates toner and is detachable from the image forming apparatus. The toner cartridge contains toner for replenishment to be supplied to the developing means provided in the image forming apparatus.

  The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which toner cartridges 8Y, 8M, 8C, and 8K are attached and detached, and the developing devices 4Y, 4M, 4C, and 4K are each developing devices (colors). And a toner supply pipe (not shown). Further, when the amount of toner stored in the toner cartridge becomes low, the toner cartridge is replaced.

  Here, in the process cartridge and the toner cartridge according to the present embodiment, the developing device corresponds to the developing unit, and the toner cartridge corresponds to the developer supply unit.

<Developer>
In this embodiment, the developer stored in the developing device (developing unit) and the supply developer stored in the toner cartridge (developer supply unit) are used in combination as a developer set.
The accommodated developer is a developer including an accommodated toner and an accommodated carrier. On the other hand, the replenishment developer is a developer containing replenishment toner, and the replenishment developer is usually composed only of replenishment toner. However, for example, when adopting a trickle development system that develops while discharging the deteriorated contained developer (accommodated toner and accommodated carrier) as a developing method, depending on the developing method, the replenishment developer is provided with a replenishment carrier. May be included. The replenishment carrier may be the same carrier as the accommodation carrier.

  Hereinafter, the details of the components of the accommodation toner and the replenishment toner will be described by referring to both toners as “toner”. Similarly, the details of the components of the accommodation carrier and the replenishment carrier will be described by referring to both carriers as carriers.

The toner will be described.
The toner has toner particles. The toner may have an external additive as necessary.

The toner particles will be described.
The toner particles include a binder resin. The toner particles may contain a colorant, a release agent, and other additives as necessary.

The binder resin will be described.
Examples of the binder resin include styrenes (eg, styrene, parachlorostyrene, α-methylstyrene, etc.), (meth) acrylic acid esters (eg, methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic acid). n-butyl, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (for example, acrylonitrile, Methacrylonitrile, etc.), vinyl ethers (eg, vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (eg, ethylene, propylene, etc.) Emissions, a homopolymer of a monomer such as butadiene) and the like, or a vinyl-based resin composed of these monomers with two or more combinations copolymer.
As the binder resin, for example, epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, non-vinyl resin such as modified rosin, a mixture of these with the vinyl resin, or these Examples also include a graft polymer obtained by polymerizing a vinyl monomer in the coexistence.
These binder resins may be used alone or in combination of two or more.

  Among these binder resins, polyester resins and styrene (meth) acrylic resins are preferable.

The polyester resin will be described.
Examples of the polyester resin include known polyester resins.

  As a polyester resin, the condensation polymer of polyhydric carboxylic acid and polyhydric alcohol is mentioned, for example. In addition, as a polyester resin, a commercial item may be used and what was synthesize | combined may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (eg, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.) Alicyclic dicarboxylic acids (for example, cyclohexanedicarboxylic acid), aromatic dicarboxylic acids (for example, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), their anhydrides, or lower (for example, having 1 or more carbon atoms) 5 or less) alkyl esters. Among these, as polyvalent carboxylic acid, aromatic dicarboxylic acid is preferable, for example.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid or a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, having 1 to 5 carbon atoms) alkyl esters.
Polyvalent carboxylic acid may be used individually by 1 type, and may use 2 or more types together.

Examples of the polyhydric alcohol include aliphatic diols (for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (for example, cyclohexanediol, cyclohexanedimethanol, Hydrogenated bisphenol A, etc.) and aromatic diols (for example, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among these, as the polyhydric alcohol, for example, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.
As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used together with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
A polyhydric alcohol may be used individually by 1 type, and may use 2 or more types together.

The glass transition temperature (Tg) of the polyester resin is preferably 50 ° C. or higher and 80 ° C. or lower, and more preferably 50 ° C. or higher and 65 ° C. or lower.
The glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, described in the method for determining the glass transition temperature in JIS K-1987 “Method for Measuring Transition Temperature of Plastics”. It is determined by “extrapolated glass transition start temperature”.

The weight average molecular weight (Mw) of the polyester resin is preferably from 5,000 to 1,000,000, and more preferably from 7,000 to 500,000.
The number average molecular weight (Mn) of the polyester resin is preferably from 2,000 to 100,000.
The molecular weight distribution Mw / Mn of the polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.
The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed with a THF solvent using a Tosoh GPC / HLC-8120GPC as a measuring device and a Tosoh column / TSKgel SuperHM-M (15 cm). The weight average molecular weight and the number average molecular weight are calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample from this measurement result.

The polyester resin is obtained by a well-known manufacturing method. Specifically, for example, the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the reaction system is reduced in pressure as necessary, and the reaction is performed while removing water and alcohol generated during the condensation polymerization.
In addition, when the monomer of the raw material is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added and dissolved as a solubilizing agent. In this case, the polycondensation reaction is performed while distilling off the solubilizer. If a monomer with poor compatibility is present in the copolymerization reaction, the monomer with poor compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polymerized together with the main component. It is good to condense.

Next, the styrene (meth) acrylic resin will be described.
Examples of the styrene (meth) acrylic resin include a copolymer obtained by copolymerizing at least a styrene monomer and a (meth) acrylic monomer. The styrene (meth) acrylic resin may be a copolymer obtained by copolymerizing other monomers in addition to the styrene monomer and the (meth) acrylic monomer.
Here, the description such as “(meth) acryl” is an expression including both “acryl” and “methacryl”.

  The styrene monomer is a monomer having a styrene skeleton. Specific examples of the styrenic monomer include styrene; vinyl naphthalene; α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, etc. Alkyl-substituted styrene; aryl-substituted styrene such as p-phenylstyrene; alkoxy-substituted styrene such as p-methoxystyrene; halogens such as p-chlorostyrene, 3,4-dichlorostyrene, 4-fluorostyrene, and 2,5-difluorostyrene Substituted styrene; m-nitrostyrene, o-nitrostyrene, p-nitrostyrene Nitro-substituted styrene and the like; and the like. Among these, styrene, p-ethyl styrene, pn-butyl styrene and the like are preferable as the styrene monomer.

  These styrene monomers may be used alone or in combination of two or more.

The (meth) acrylic monomer is a monomer having a (meth) acryloyl group. Specific examples of the (meth) acrylic monomer include n-methyl (meth) acrylate, n-ethyl (meth) acrylate, n-propyl (meth) acrylate, and n-butyl (meth) acrylate. , N-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acryl N-dodecyl acid, n-lauryl (meth) acrylate, n-tetradecyl (meth) acrylate, n-hexadecyl (meth) acrylate, n-octadecyl (meth) acrylate, isopropyl (meth) acrylate, (meth ) Isobutyl acrylate, t-butyl (meth) acrylate, isopentyl (meth) acrylate, amyl (meth) acrylate, ne (meth) acrylate Pentyl, isohexyl (meth) acrylate, isoheptyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, (meth) acrylic (Meth) acrylic acid alkyl esters such as lauryl acid, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, isobornyl (meth) acrylate;
Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, pentanediol di (meth) acrylate, hexanediol di (meth) acrylate, Di (meth) acrylic acid esters such as nonanediol di (meth) acrylate and decanediol di (meth) acrylate (meth) acrylic acid carboxy-substituted alkyl esters such as (meth) acrylic acid β-carboxyethyl;
2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, (Meth) acrylic acid hydroxy-substituted alkyl esters such as (meth) acrylic acid 4-hydroxybutyl;
(Meth) acrylic acid alkoxy substituted alkyl esters such as (meth) acrylic acid 2-methoxyethyl;
Etc.
Among these (meth) acrylic acid esters, (meth) acrylic having an alkyl group having 2 to 14 carbon atoms (preferably 2 to 10 carbon atoms, more preferably 3 to 8 carbon atoms) from the viewpoint of fixability. Acid esters are preferred.

  Examples of the (meth) acrylic monomer include (meth) acrylic acid in addition to the above (meth) acrylic acid ester.

  These (meth) acrylic monomers may be used alone or in combination of two or more.

  Examples of other monomers include ethylenically unsaturated nitriles (acrylonitrile, methacrylonitrile, etc.), vinyl ethers (vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl). Ketones), divinyls (divinyl adipate, etc.), olefins (ethylene, propylene, butadiene, etc.), and the like.

In the styrene (meth) acrylic resin, the ratio of the styrene monomer to the total polymerization components (that is, the ratio of the repeating unit derived from the styrene monomer to the mass of the entire resin) is 60 from the viewpoint of image storability. The content is preferably not less than mass%, preferably not less than 65 mass% and not more than 90 mass%, more preferably not less than 70 mass% and not more than 85 mass%.
On the other hand, the ratio of the (meth) acrylic monomer to the total polymerization components (that is, the ratio of the repeating unit derived from the (meth) acrylic monomer to the total mass of the resin) is 10 masses from the viewpoint of fixing properties. % To 40% by mass, more preferably 10% to 35% by mass.

The glass transition temperature (Tg) of the styrene (meth) acrylic resin is preferably 40 ° C. or higher and 70 ° C. or lower, and more preferably 50 ° C. or higher and 65 ° C. or lower from the viewpoint of excellent powder characteristics of the toner.
The glass transition temperature is measured in the same manner as the glass transition temperature of the polyester resin.

The weight average molecular weight (Mw) of the styrene (meth) acrylic resin is preferably 20,000 or more and 200,000 or less, more preferably 40,000 or more and 100,000 or less, from the viewpoint of excellent powder characteristics of the toner.
The number average molecular weight (Mn) of the styrene (meth) acrylic resin is preferably 5,000 or more and 30,000 or less.
The molecular weight distribution Mw / Mn of the styrene (meth) acrylic resin is preferably 1 or more and 10 or less, and more preferably 2 or more and 6 or less.
The weight average molecular weight and number average molecular weight are measured in the same manner as the molecular weight of the polyester resin.

A well-known polymerization method (radical polymerization methods such as soap-free emulsion polymerization, suspension polymerization, miniemulsion polymerization, and microemulsion polymerization) is applied to the synthesis of the styrene (meth) acrylic resin.
In the polymerization, the crosslinking density of the styrene (meth) acrylic resin may be controlled by adjusting the amount of the crosslinking agent (for example, decanediol diacrylate).

The content of the binder resin will be described.
The content of the binder resin is, for example, preferably 40% by weight to 95% by weight, more preferably 50% by weight to 90% by weight, and more preferably 60% by weight to 85% by weight with respect to the entire toner particles. Further preferred.

The colorant will be described. Examples of the colorant include carbon black, chrome yellow, hansa yellow, benzidine yellow, selenium yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, Brilliant Carmine 3B, Brilliant Carmine 6B, Dupont Oil Red, Pyrazolone Red, Risor Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Various pigments such as blue, phthalocyanine green, malachite green oxalate, or acrid , Xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane And various dyes such as thiazole series.
A colorant may be used individually by 1 type and may use 2 or more types together.

  As the colorant, a surface-treated colorant may be used as necessary, or it may be used in combination with a dispersant. A plurality of colorants may be used in combination.

  The content of the colorant is, for example, preferably 1% by mass or more and 30% by mass or less, and more preferably 3% by mass or more and 15% by mass or less with respect to the entire toner particles.

The release agent will be described.
Examples of mold release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; and ester waxes such as fatty acid esters and montanic acid esters. And so on. The release agent is not limited to this.

The melting temperature of the release agent is preferably 50 ° C. or higher and 110 ° C. or lower, and more preferably 60 ° C. or higher and 100 ° C. or lower.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) according to the “melting peak temperature” described in JIS K-1987 “Method for measuring the transition temperature of plastics”.

  The content of the release agent is, for example, preferably 1% by mass to 20% by mass and more preferably 5% by mass to 15% by mass with respect to the entire toner particles.

-Other additives-
Examples of other additives include known additives such as a magnetic material, a charge control agent, and inorganic powder. These additives are contained in the toner particles as internal additives.

The characteristics of the toner particles will be described.
The toner particles may be toner particles having a single layer structure, or toner particles having a so-called core / shell structure composed of a core (core particle) and a coating layer (shell layer) covering the core. May be.
Here, the core / shell structure toner particles include, for example, a core portion including a binder resin and, if necessary, other additives such as a colorant and a release agent, and a binder resin. It is good to be comprised with the comprised coating layer.

  The volume average particle diameter (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, and more preferably 4 μm or more and 8 μm or less.

The various average particle diameters and various particle size distribution indexes of the toner particles are measured using Coulter Multisizer II (manufactured by Beckman-Coulter), and the electrolyte is measured using ISOTON-II (manufactured by Beckman-Coulter). The
In the measurement, 0.5 mg to 50 mg of a measurement sample is added as a dispersant to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate). This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolyte in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm to 60 μm is measured using a 100 μm aperture with a Coulter Multisizer II. taking measurement. The number of particles to be sampled is 50,000.
For the particle size range (channel) divided based on the measured particle size distribution, the cumulative distribution is drawn from the smaller diameter side to the volume and number, respectively, and the particle size to be 16% is the volume particle size D16v, the number particle size D16p, a particle size that is 50% cumulative is defined as a volume average particle size D50v, a cumulative number average particle size D50p, and a particle size that is 84% cumulative is defined as a volume particle size D84v and a number particle size D84p.
Using these, the volume average particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 and the number average particle size distribution index (GSDp) is calculated as (D84p / D16p) ^1/2 .

  The shape factor SF1 of the toner particles is preferably 110 or more and 150 or less, and more preferably 120 or more and 140 or less.

The shape factor SF1 is obtained by the following formula.
Formula: SF1 = (ML ² / A) × (π / 4) × 100
In the above formula, ML represents the absolute maximum length of the toner, and A represents the projected area of the toner.
Specifically, the shape factor SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and is calculated as follows. That is, by capturing an optical microscope image of particles dispersed on the surface of a slide glass into a Luzex image analyzer using a video camera, obtaining the maximum length and projected area of 100 particles, calculating by the above formula, and obtaining the average value can get.

The external additive will be described.
Examples of the external additive include inorganic particles. As the inorganic particles, SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO. _{SiO 2, K 2 O · (} TiO 2) n, Al 2 O 3 · 2SiO 2, CaCO 3, MgCO 3, BaSO 4, MgSO 4 , and the like.

The surface of the inorganic particles as an external additive is preferably subjected to a hydrophobic treatment. The hydrophobic treatment is performed, for example, by immersing inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, aluminum coupling agents and the like. These may be used individually by 1 type and may use 2 or more types together.
The amount of the hydrophobizing agent is usually 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles, for example.

  Examples of external additives include resin particles (resin particles such as polystyrene, polymethyl methacrylate (PMMA), and melamine resin), cleaning activators (for example, metal salts of higher fatty acids typified by zinc stearate, fluorine-based high molecular weight substances). Particle) and the like.

  The external addition amount of the external additive is, for example, preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.01% by mass or more and 2.0% by mass or less with respect to the toner particles.

A method for producing toner will be described.
The toner is obtained by externally adding an external additive to the toner particles after producing the toner particles.

The toner particles may be produced by any of a dry production method (for example, a kneading and pulverizing method) and a wet production method (for example, an aggregation coalescence method, a suspension polymerization method, a dissolution suspension method, etc.). The production method of the toner particles is not particularly limited, and a known production method is adopted.
Among these, it is preferable to obtain toner particles by an aggregation and coalescence method.

Describe your career.
There is no restriction | limiting in particular as a carrier, A well-known carrier is mentioned. As a carrier, for example, a coated carrier in which the surface of a core made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and mixed in a matrix resin; a porous magnetic powder is impregnated with a resin Resin impregnated type carriers; and the like.
Note that the magnetic powder-dispersed carrier and the resin-impregnated carrier may be a carrier in which the constituent particles of the carrier are used as a core material and coated with a coating resin.

  Examples of the magnetic powder include magnetic metals such as iron, nickel, and cobalt, and magnetic oxides such as ferrite and magnetite.

Examples of the coating resin and matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid copolymer. Examples thereof include a polymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenol resin, and an epoxy resin.
Note that the coating resin and the matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

Here, in order to coat the surface of the core material with the coating resin, a method of coating with a coating layer forming solution obtained by dissolving the coating resin and, if necessary, various additives in an appropriate solvent may be mentioned. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, coating suitability, and the like.
Specific resin coating methods include a dipping method in which the core material is immersed in the coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the surface of the core material, and a state in which the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a coating layer forming solution is sprayed, a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater, and the solvent is removed.

Here, among the developers, the mixing ratio (mass ratio) of the accommodation toner and the accommodation carrier in the accommodation developer is preferably accommodation toner: accommodation carrier = 1: 100 to 30: 100, and 3: 100 to 20: 100. Is more preferable.
On the other hand, when the replenishment developer includes a replenishment carrier, the mixing ratio of the replenishment toner and the replenishment carrier is preferably replenishment toner: replenishment carrier = 100: 5 to 100: 30, and more preferably 100: 10 to 100: 25.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, in the following examples, “part” means mass part and “%” means mass%.

<Preparation of polyester resin particle dispersion>
(Polyester resin particle dispersion (PE1))
-Ethylene glycol (Wako Pure Chemical Industries, Ltd.): 37 parts by mass-Neopentyl glycol (Wako Pure Chemical Industries, Ltd.): 65 parts by mass, 1,9 Nonanediol (Wako Pure Chemical Industries, Ltd.) ]: 32 parts by mass / terephthalic acid (manufactured by Wako Pure Chemical Industries, Ltd.): 96 parts by mass The above monomer was charged into a flask and the temperature was raised to 200 ° C. over 1 hour, and the reaction system was stirred. After confirmation, 1.2 parts of dibutyltin oxide was added. Further, while distilling off the generated water, the temperature was increased from the same temperature to 240 ° C. over 6 hours, and the dehydration condensation reaction was continued at 240 ° C. for another 4 hours. The acid value was 9.4 mgKOH / g, and the weight average molecular weight. A polyester resin (PE1) having a glass transition temperature of 13,000 and 62 ° C. was obtained.

Next, the polyester resin (PE1) was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) at a rate of 100 parts per minute. A 0.37% diluted aqueous ammonia solution obtained by diluting reagent ammonia water with ion-exchanged water is put into a separately prepared aqueous medium tank, and the polyester is heated at 120 ° C. with a heat exchanger at a rate of 0.1 liter per minute. Simultaneously with the resin melt, it was transferred to the Cavitron. The Cavitron is operated under the conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² .
A polyester resin particle dispersion (PE1) having a volume average particle diameter D50v = 160 nm and a solid content of 30% was obtained.

<Preparation of styrene acrylic resin particle dispersion>
(Styrene acrylic resin particle dispersion (SA1))
-Styrene: 320 parts by mass-n-Butyl acrylate: 80 parts by mass-Acrylic acid: 12 parts by mass-10-dodecanethiol: 2 parts by mass Nonipol 400 (manufactured by Sanyo Chemical Co., Ltd.) 6 parts by mass and anionic surfactant (Neogen SC, Daiichi Kogyo Seiyaku Co., Ltd.) 10 parts by mass in ion-exchanged water 550 parts by mass in a flask While emulsifying and dispersing, slowly mixing for 10 minutes, 50 parts by mass of ion-exchanged water having 4 parts by mass of ammonium persulfate dissolved therein was added thereto. After carrying out nitrogen substitution, while stirring the inside of the flask, the contents were heated in an oil bath until the temperature reached 70 ° C., and emulsion polymerization was continued for 5 hours. As a result, a styrene acrylic resin particle dispersion (SA1) having a volume average particle diameter D50v = 210 nm, a glass transition temperature Tg = 50 ° C., a weight average molecular weight Mw = 38000, and a solid content of 30% was obtained.

<Preparation of colorant particle dispersion>
(Preparation of colorant particle dispersion (1))
Cyan pigment: 10 parts by mass [C.I. I. Pigment Blue 15: 3, manufactured by Dainichi Seika Kogyo Co., Ltd.]
Anionic surfactant: 2 parts by mass [Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.]
-Ion-exchanged water: 80 parts by mass The above components are mixed and dispersed for 1 hour by a high-pressure impact disperser optimizer [HJP30006, manufactured by Sugino Machine Co., Ltd.], with a volume average particle size of 180 nm and a solid content of 20% by mass. A colorant particle dispersion (1) was obtained.

<Preparation of release agent particle dispersion>
(Releasing agent particle dispersion (1))
-Paraffin wax [HNP 9, manufactured by Nippon Seiki Co., Ltd.]: 50 parts by mass-Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku): 2 parts by mass-Ion-exchanged water: 200 parts by mass The mixture was thoroughly mixed and dispersed with IKA's Ultra Turrax T50, and then dispersed with a pressure discharge homogenizer to obtain a release agent particle dispersion having a volume average particle size of 200 nm and a solid content of 20%. Obtained.

<Preparation of toner particles>
(Production of toner particles (1))
Styrene acrylic resin particle dispersion (SA1): 200 parts by mass Colorant particle dispersion (1): 25 parts by weight Release agent particle dispersion (1): 30 parts by mass Polyaluminum chloride: 0.4 parts by mass Parts / ion-exchanged water: 100 parts by mass The above components were put into a stainless steel flask, mixed and dispersed using an IKA ultra turrax, and then stirred up to 48 ° C. while stirring the flask in an oil bath for heating. Heated. After maintaining at 48 ° C. for 30 minutes, 70 parts of styrene acrylic resin particle dispersion (SA1) was added as an additional resin particle dispersion.
Then, after adjusting the pH in the system to 8.0 using an aqueous sodium hydroxide solution having a concentration of 0.5 mol / L, the stainless steel flask is sealed, and the stirring shaft seal is magnetically sealed while stirring is continued. Heat to 90 ° C. and hold for 3 hours. After completion of the reaction, the temperature was lowered at a rate of 2 ° C./min, filtered, washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed with 3 L of ion exchange water at 30 ° C., and stirred and washed at 300 rpm for 15 minutes. This washing operation was further repeated 6 times, and when the pH of the filtrate became 7.54 and the electric conductivity was 6.5 μS / cm, No. was obtained by Nutsche suction filtration. Solid-liquid separation was performed using 5A filter paper. Next, vacuum drying was continued for 12 hours to obtain toner particles.
The volume average particle diameter D50v of the toner particles was measured with a Coulter counter and found to be 5.8 μm and SF1 was 130.

(Production of toner particles (2) to (6))
According to Table 1, toner particles (2) to (6) were produced in the same manner as the toner particles (1) except that the type of the resin particle dispersion was changed.

<Production of toner>
(Production of toners (1) to (6))
Toner (1): To 100 parts by mass, the types and number of external additives shown in Table 1 were added and mixed by a high speed mixer to obtain toners (1) to (6). The obtained toner was a negatively chargeable toner. The external additives used are as follows.

-Details of external additives-
External additive (1): trade name “JMT200 (manufacturer: manufactured by Teica)”, surface-treated titanium particles, volume average particle size = 20 nm
External additive (2): trade name “STT100H (manufacturer: manufactured by Titanium Industry Co., Ltd.)”, surface-treated titanium particles, volume average particle diameter = 40 nm
External additive (3): trade name “X24 (manufacturer: manufactured by Shin-Etsu Chemical Co., Ltd.)”, hydrophobized silica particles, volume average particle size = 140 nm
・
<Creation of carrier>
(Production of carrier (1))
Ferrite particles (volume average particle size 45 μm) 100 parts by mass Toluene 14 parts by mass Styrene / methyl methacrylate copolymer (copolymerization ratio (styrene / methyl methacrylate) 20/80) 3 parts by mass Carbon black 0.2 mass Part The above components excluding ferrite particles are dispersed by a sand mill to prepare a dispersion, and the dispersion is placed in a vacuum degassing kneader together with ferrite particles, and dried under reduced pressure while stirring to obtain carrier (1). It was.

(Production of carrier (2))
Carrier (2) was obtained in the same manner as carrier (1) except that the copolymerization ratio of styrene / metal methacrylate copolymer (styrene / methyl methacrylate) was changed to 10/90.

(Production of carrier (3))
Carrier (3) was obtained in the same manner as carrier (1) except that the copolymerization ratio of styrene / metal methacrylate copolymer (styrene / methyl methacrylate) was 15/85.

(Production of carrier (4))
Carrier (4) was obtained in the same manner as carrier (1) except that the copolymerization ratio of styrene / metal methacrylate copolymer (styrene / methyl methacrylate) was changed to 8/92.

(Production of carrier (5))
Carrier (5) was obtained in the same manner as carrier (1) except that the copolymerization ratio of styrene / metal methacrylate copolymer (styrene / methyl methacrylate) was changed to 30/70.

(Production of carrier (6))
Carrier (6) was obtained in the same manner as carrier (1) except that the copolymerization ratio of styrene / metal methacrylate copolymer (styrene / methyl methacrylate) was changed to 7/93.

(Production of carrier (7))
Carrier (7) was obtained in the same manner as carrier (1) except that the copolymerization ratio of styrene / metal methacrylate copolymer (styrene / methyl methacrylate) was changed to 5/95.

<Example 1>
Toner (1): 10 parts by mass and carrier (1): 90 parts by mass were mixed in a V-type blender at a stirring speed of 20 rpm for 15 minutes to produce a housed developer 1. An image forming apparatus “trade name: Fuji Xerox Co., Ltd., DocuCentreColor 400CP, a developing unit of a developing device of a modified machine, developer 1 was accommodated in the developing unit. On the other hand, toner (2) was used as a replenishment developer (supplement toner). In a toner cartridge.
The image forming apparatus that accommodated each developer was used as the image forming apparatus of Example 1.

<Examples 2-5, Comparative Examples 1-2>
According to Table 2, the image forming apparatus of each example was obtained in the same manner as in Example 1 except that the type of toner and carrier of the housed developer and the type of toner of the replenishment developer (replenishment toner) were changed. .

<Measurement>
(Measurement of standard charge)
The relationship between the standard charging ability of the toner and the carrier used in the image forming apparatus of each example was measured according to the method described above. The results are shown in Table 2.

<Evaluation>
The following evaluation was performed using the image forming apparatus of each example. The results are shown in Table 2.

(Evaluation of fogging)
Under normal temperature and humidity conditions (temperature: 25 ° C., humidity: about 50%), an image with an image density of 1% is output continuously for 10,000 sheets, and when the 10,000 sheets are output, the developed photoconductor is temporarily stopped. The non-image area on the photoreceptor was transferred to tape. Then, this tape was affixed on white paper and the fogging of the tape part was evaluated.
The evaluation criteria are as follows. However, B (◯) and above are levels that can be used without problems in actual use.
A (◎): No fog toner can be confirmed at all visually (B): Fog toner can hardly be confirmed at the visual level C (△): Fog can be confirmed slightly at the visual level D (x): Fog at the visual level Is clearly visible

(Evaluation of image density stability)
Under normal temperature and humidity conditions (temperature of 25 ° C, humidity of about 50%), the image density of 1% is output continuously at 10,000 sheets, and the image density at the time of 1000 sheet output and 10,000 sheet output is The concentration was measured with a concentration measuring device “X-rite 404A” manufactured by X-rite. Then, the difference in image density between the output of 1000 sheets and the output of 10,000 sheets was obtained, and the image density stability was evaluated.
The evaluation criteria are as follows. However, B (◯) and above are levels that can be used without problems in actual use.
A (◎): Difference in density is 0.10 or less B (◯): Difference in density exceeds 0.10, 0.15 or less C (Δ): Difference in density exceeds 0.15, 0.20 or less D (×): Concentration difference exceeds 0.20

From the above results, it can be seen that the present example has obtained better results for the evaluation of the fog than the comparative example.
In addition, in this embodiment, it can be seen that a better result is obtained in the evaluation of the image density stability than in the comparative example.

1Y, 1M, 1C, 1K, photoconductor (an example of an image carrier)
2Y, 2M, 2C, 2K, charging roll (an example of charging means)
3. Exposure device (an example of electrostatic charge image forming means)
3Y, 3M, 3C, 3K Laser beams 4Y, 4M, 4C, 4K Developing device (an example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (an example of primary transfer means)
6Y, 6M, 6C, 6K Photoconductor cleaning device (an example of cleaning means)
8Y, 8M, 8C, 8K Toner cartridge 10Y, 10M, 10C, 10K Image forming unit 20 Intermediate transfer belt (an example of an intermediate transfer member)
22 Drive roll 24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
30 Intermediate transfer member cleaning device 107 Photosensitive member (an example of an image holding member)
108 Charging roll (an example of charging means)
109 Exposure apparatus (an example of electrostatic charge image forming means)
111 Developing device (an example of developing means)
112 Transfer device (an example of transfer means)
113 photoconductor cleaning device (an example of cleaning means)
115 Fixing device (an example of fixing means)
116 Mounting rail 117 Housing 118 Opening 200 for exposure Process cartridge 300 Recording paper (an example of a recording medium)
P Recording paper (an example of a recording medium)

Claims (7)

Development that contains a first developer containing a first negatively chargeable toner and a carrier, and that develops the electrostatic latent image formed on the image carrier with the first developer to form a toner image. And
Development in which a second developer containing a second negatively chargeable toner whose charged column is located on the positive electrode side of the first negatively chargeable toner is contained, and the second developer is supplied to the developing unit. An agent replenishment section;
A developing device comprising: 2. The system according to claim 1, wherein when the standard charging ability of the first negatively chargeable toner is EC _A and the standard charging ability of the second negatively chargeable toner is EC _B , the following relational expression (1) is satisfied. Development device.
Relational expression (1): 5 ≦ EC _A −EC _B ≦ 30 Standard charging ability of said first negative chargeable toner and EC _A, the standard charging capacity of the second negative chargeable toner and EC _B, when the standard charging ability of the carrier to the EC _C, following relationships The developing device according to claim 1 or 2, which satisfies (2).
Relational expression (2): 0.3 ≦ | EC _A −EC _B | / | EC _C −EC _B | ≦ 1.0 An image carrier,
A charging device for charging the surface of the image carrier;
A latent image forming apparatus for forming an electrostatic latent image on the surface of the charged image carrier;
4. A developing device that develops the electrostatic latent image formed on the image holding member with a developer to form a toner image, and the developing device according to claim 1. ,
A transfer device for transferring the toner image formed on the image carrier to a recording medium;
An image forming apparatus comprising: A developing step of developing the electrostatic latent image formed on the image holding member with a first developer containing a first negatively chargeable toner and a carrier to form a toner image;
A replenishment step of replenishing the first developer with a second developer containing a second negatively chargeable toner having a charged column located on the positive electrode side of the first negatively chargeable toner;
A developing method comprising: A charging step for charging the surface of the image carrier;
A latent image forming step of forming an electrostatic latent image on the surface of the charged image carrier;
A developing step of developing the electrostatic latent image formed on the image holding member with a first developer including a first negatively chargeable toner and a carrier to form a toner image;
A transfer step of transferring the toner image formed on the image carrier to a recording medium;
A replenishment step of replenishing the first developer with a second developer containing a second negatively chargeable toner having a charged column located on the positive electrode side of the first negatively chargeable toner;
An image forming method comprising: A first developer that is accommodated in a developing unit of a developing device that develops an electrostatic latent image formed on an image carrier with a first developer to form a toner image, and the first negatively charged A first developer containing a functional toner and a carrier;
A second developer housed in a developer replenishing portion of a developing device that replenishes the developing portion with a second developer, wherein a charged column is located on the positive electrode side of the first negatively chargeable toner. A second developer containing a second negatively chargeable toner;
A developer set.

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