JP2021047271A - Image formation device - Google Patents

Abstract

To provide an image formation device which suppresses occurrence of fog in the low temperature and low humidity environment and reduction in image density in the high temperature and high humidity environment.SOLUTION: In an image formation device having an air supply port and a screw pump in a toner supply passage, a toner container for replenishment stores toner particles, and a toner for replenishment containing silica particles whose number average particle diameter is 110 nm or more and 130 nm or less, large diameter side number particle size distribution index (upper side GSDp) is less than 1.080, mean circularity is 0.94 or more and 0.98 or less, and ratio of 0.92 or more of circularity is at least 80 number%.SELECTED DRAWING: None

Description

The present invention relates to an image forming apparatus.

Patent Document 1 describes a pump means for automatically supplying toner to a developing unit, a toner storage means provided connected to the pump means, and air for fluidizing the toner stored in the toner storage means. A toner replenishing device including a supply means is disclosed.
Patent Document 2 discloses a toner transfer pump including a stator having two spirally extending grooves and a rotor rotatably arranged in a through hole of the stator.
Patent Document 3 describes that the degree of compression cohesion is 60% or more and 95% or less, the particle compression ratio is 0.20 or more and 0.40 or less, the average circle equivalent diameter is 40 nm or more and 200 nm or less, and the particle dispersion degree is Silica particles of 90% or more and 100% or less are disclosed.
Patent Document 4 describes silica having a volume average particle size of 80 nm or more and 300 nm or less, an average circularity of 0.92 or more and 0.935 or less, and a circularity geometric standard deviation of 1.02 or more and 1.15 or less. The particles and the toner containing the silica particles are disclosed.
Patent Document 5 discloses hydrophobic spherical silica particles having a particle size in the range of 0.01 μm to 5 μm and a circularity in the range of 0.8 to 1.
Patent Document 6 discloses spherical hydrophobic silica particles having an average particle size of 0.01 μm to 5 μm.

Japanese Unexamined Patent Publication No. 2002-006536 Japanese Unexamined Patent Publication No. 2002-132827 Japanese Unexamined Patent Publication No. 2017-057094 Japanese Unexamined Patent Publication No. 2013-053027 Japanese Unexamined Patent Publication No. 2008-174430 Japanese Patent No. 2001-194824

According to the present disclosure, in an image forming apparatus having an air supply port and a screw pump in a toner replenishment path, a replenishment toner container has a number average particle diameter of 110 nm or more and 130 nm or less and a large diameter side number particle size distribution index (upper GSDp). ) Provides an image forming apparatus that suppresses fog in a low temperature and low humidity environment and a decrease in image density in a high temperature and high humidity environment as compared with the case where a replenishing toner containing silica particles having a value of 1.080 or more is contained. The task is to do.

Specific means for solving the above problems include the following aspects.

<1> Image holder and
A charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means that accommodates an electrostatic charge image developer and develops an electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
A replenishment toner container for accommodating the replenishment toner to be replenished in the developing means, and
It is provided with an air supply port and a screw pump for connecting the replenishing toner container and the developing means, and a toner replenishing path for replenishing the replenishing toner to the developing means.
The replenishment toner has toner particles and a number average particle diameter of 110 nm or more and 130 nm or less, a large diameter side number particle size distribution index (upper GSDp) of less than 1.080, and an average circularity of 0.94 or more and 0. Containing silica particles having a degree of .98 or less and a circularity of 0.92 or more and a ratio of 80% by number or more.
Image forming device.
<2> The image forming apparatus according to <1>, wherein the silica particles have a large-diameter side number particle size distribution index (upper GSDp) of less than 1.075.
<3> The image forming apparatus according to <1> or <2>, wherein the silica particles have a small diameter side number particle size distribution index (lower GSDp) of less than 1.080.
<4> The image forming apparatus according to any one of <1> to <3>, wherein the silica particles have an average circularity of 0.95 or more and 0.97 or less.
<5> The image forming apparatus according to any one of <1> to <4>, wherein the silica particles have a circularity of 0.92 or more and a ratio of 85 number% or more.
<6> The image forming apparatus according to any one of <1> to <5>, wherein the replenishing toner further contains inorganic oxide particles having a number average particle diameter of 5 nm or more and 50 nm or less.
<7> The image forming apparatus according to <6>, wherein the content of the inorganic oxide particles contained in the replenishing toner is smaller than the content of the silica particles.
<8> The method according to <6> or <7>, wherein the ratio Da / Db of the number average particle size Da of the silica particles to the number average particle size Db of the inorganic oxide particles is 2.5 or more and 20 or less. Image forming device.
<9> The image forming apparatus according to any one of <1> to <8>, wherein the toner particles contain a styrene acrylic resin as a binder resin.
<10> The image forming apparatus according to any one of <1> to <9>, wherein the toner particles contain an amorphous polyester resin as a binder resin.
<11> The image forming apparatus according to any one of <1> to <10>, wherein the screw pump is a rotary positive displacement type uniaxial eccentric screw pump.
<12> The image forming apparatus according to any one of <1> to <11>, wherein the screw pump has a stator and a rotor arranged inside the stator, and the stator is an elastic body. ..
<13> The image forming apparatus according to <12>, wherein the elastic body is at least one selected from the group consisting of nitrile butadiene rubber, ethylene propylene rubber, silicone rubber, and urethane rubber.

According to the invention according to <1>, <9>, <10>, <11>, <12> or <13>, a replenishing toner is provided in an image forming apparatus having an air supply port and a screw pump in the toner replenishment path. Compared with the case where the container contains a replenishing toner containing silica particles having a number average particle diameter of 110 nm or more and 130 nm or less and a large diameter side number particle size distribution index (upper GSDp) of 1.080 or more. An image forming apparatus that suppresses the generation of fog in a low temperature and low humidity environment and the decrease in image density in a high temperature and high humidity environment is provided.
According to the invention according to <2>, fog occurs in a low temperature and low humidity environment and an image in a high temperature and high humidity environment as compared with the case where the large diameter side particle size distribution index (upper GSDp) of the silica particles is 1.075 or more. An image forming apparatus that suppresses a decrease in density is provided.
According to the invention according to <3>, fog occurs in a low temperature and low humidity environment and an image in a high temperature and high humidity environment as compared with the case where the small diameter side particle size distribution index (lower GSDp) of the silica particles is 1.080 or more. An image forming apparatus that suppresses a decrease in density is provided.
According to the invention according to <4>, fog occurs in a low temperature and low humidity environment and image density decreases in a high temperature and high humidity environment as compared with the case where the average circularity of silica particles is less than 0.95 or more than 0.97. An image forming apparatus that suppresses the above is provided.
According to the invention according to <5>, fog occurs in a low temperature and low humidity environment and image density decreases in a high temperature and high humidity environment, as compared with the case where the ratio of circularity of 0.92 or more in silica particles is less than 85% by number. An image forming apparatus that suppresses the above is provided.
According to the invention according to <6>, fog occurs in a low temperature and low humidity environment and image density decreases in a high temperature and high humidity environment as compared with the case where inorganic oxide particles having a number average particle size of 5 nm or more and 50 nm or less are not contained. An image forming apparatus for suppressing the above is provided.
According to the invention according to <7>, fog occurs in a low temperature and low humidity environment and image density decreases in a high temperature and high humidity environment as compared with the case where the content of inorganic oxide particles is larger than the content of silica particles. An image forming apparatus for suppressing is provided.
According to the invention according to <8>, the ratio Da / Db of the number average particle size Da of the silica particles to the number average particle size Db of the inorganic oxide particles is less than 2.5 or more than 20 as compared with the case where the ratio Da / Db is less than 2.5 or more than 20. An image forming apparatus that suppresses the generation of fog in a low temperature and low humidity environment and the decrease in image density in a high temperature and high humidity environment is provided.

It is a schematic block diagram which shows an example of the image forming apparatus which concerns on this embodiment. It is a schematic block diagram which shows an example of the image holder, the developing means, the toner replenishment path, and the replenishment toner container provided in the image forming apparatus which concerns on this embodiment.

Hereinafter, embodiments of the present disclosure will be described. These explanations and examples illustrate the embodiments and do not limit the scope of the embodiments.

The numerical range indicated by using "~" in the present disclosure indicates a range including the numerical values before and after "~" as the minimum value and the maximum value, respectively.

In the numerical range described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described stepwise. .. Further, in the numerical range described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.

In the present disclosure, the term "process" is included in this term not only as an independent process but also as long as the intended purpose of the process is achieved even if it cannot be clearly distinguished from other processes.

When the embodiment is described in the present disclosure with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Further, the size of the members in each figure is conceptual, and the relative relationship between the sizes of the members is not limited to this.

In the present disclosure, each component may contain a plurality of applicable substances. When referring to the amount of each component in the composition in the present disclosure, if a plurality of substances corresponding to each component are present in the composition, unless otherwise specified, the plurality of types present in the composition. It means the total amount of substances.

In the present disclosure, a plurality of types of particles corresponding to each component may be contained. When a plurality of particles corresponding to each component are present in the composition, the particle size of each component means a value for a mixture of the plurality of particles present in the composition unless otherwise specified.

In the present disclosure, the notation "(meth) acrylic" means that either "acrylic" or "methacryl" may be used.

<Image forming device>
The image forming apparatus according to this embodiment is
Image holder and
A charging means that charges the surface of the image holder,
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of a charged image holder,
A developing means that accommodates a static charge image developer and develops the static charge image formed on the surface of the image holder as a toner image by the static charge image developer.
A transfer means for transferring a toner image formed on the surface of an image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
A replenishment toner container for accommodating replenishment toner to be replenished to the developing means,
It connects the replenishing toner container and the developing means, has an air supply port and a screw pump, and has a toner replenishment path for replenishing the replenishing toner to the developing means.
In the image forming apparatus according to the present embodiment, the replenishing toner is the toner particles, the number average particle diameter is 110 nm or more and 130 nm or less, and the large diameter side number particle size distribution index (upper GSDp) is less than 1.080. It contains silica particles having an average circularity of 0.94 or more and 0.98 or less and a number ratio of 0.92 or more and a number ratio of 80% or more.

The image forming apparatus according to the present embodiment has fog generation in a low temperature and low humidity environment (for example, temperature 10 ° C. and relative humidity 10%) and image density in a high temperature and high humidity environment (for example, temperature 30 ° C. and relative humidity 85%). Suppresses the decrease in. The following is presumed as the mechanism.

As a powder transporting means, a means for supplying air to the powder, fluidizing the powder, and transporting the powder with a screw pump (hereinafter referred to as "screw pump type transport means") is known. The screw pump type transfer means is superior to other transfer means such as August Cru in terms of miniaturization and freedom of arrangement of the transfer device and a small mechanical load on the powder. However, since the screw pump type transport means is not a means for continuously stirring the powder like Augustus cru, the fluidity of the powder itself has a high degree of influence on the transport efficiency. In order to ensure the stability of the toner replenishment speed in the toner replenishment path provided with the screw pump type transport means and suppress image defects, it is required to improve the environmental stability of the toner fluidity. Therefore, in the present embodiment, the replenishing toner is configured as described below.

As a toner externalizing agent, silica particles having a number average particle diameter of 110 nm or more and 130 nm or less (referred to as "large-diameter silica particles" in this description) are expected to have a spacer effect (an effect of creating an appropriate distance between toner particles). .) Is used. The large-diameter silica particles may include larger silica particles (referred to as "coarse silica particles" in the present description), and the coarse silica particles have an effect of further increasing the fluidity of the toner. Therefore, the toner containing the coarse silica particles tends to move easily in the toner supply path, and the supply to the developing means tends to be excessive. When the amount of toner in the developing means becomes excessive, the charge due to friction with the carrier in the developing means becomes insufficient, and as a result, fog occurs (“fog” is an unintended point on the image forming surface of the recording medium. This is a phenomenon in which a similar image appears.) This phenomenon is remarkable in a low temperature and low humidity environment where the fluidity of the toner is higher.
Therefore, in the present embodiment, the large-diameter side number particle size distribution index (upper GSDp) of the large-diameter silica particles contained in the replenishing toner is less than 1.080, that is, by suppressing the content of the coarse silica particles. The above phenomenon is suppressed, and as a result, the occurrence of fog in a low temperature and low humidity environment is suppressed.
Further, when the average circularity of the large-diameter silica particles exceeds 0.98, the fluidity of the toner tends to increase and the supply to the developing means tends to be excessive. Therefore, the average circularity of the large-diameter silica particles is set to 0. The setting is 98 or less to suppress the occurrence of fog in a low temperature and low humidity environment.

Large-diameter silica particles are externally attached to the toner in anticipation of a spacer effect. However, if the circularity of the large-diameter silica particles is low, the number of contact points between the large-diameter silica particles and the toner particles increases, and the toner aggregates with each other. Tends to occur. Therefore, the toner containing the large-diameter silica particles having a low circularity tends to aggregate in the toner supply path, and as a result, the toner supply to the developing means is insufficient and the image density is lowered. This phenomenon is remarkable in a high temperature and high humidity environment where the fluidity of the toner becomes lower.
Therefore, in the present embodiment, the average circularity of the large-diameter silica particles contained in the replenishing toner is 0.94 or more, and the proportion of the large-diameter silica particles having a circularity of 0.92 or more is 80% or more. The above phenomenon is suppressed, and as a result, the decrease in image density in a high temperature and high humidity environment is suppressed.

The configuration of the image forming apparatus according to the present embodiment will be described in detail below.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers the toner image formed on the surface of the image holder to the recording medium; the toner image formed on the surface of the image holder is transferred to the intermediate transfer body. An intermediate transfer type device that first transfers the toner image to the surface and then secondarily transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium; after transferring the toner image, cleans the surface of the image holder before charging. A known image forming apparatus such as a device provided with cleaning means; a device provided with static elimination means for irradiating the surface of the image holder with static elimination light after transfer of the toner image and before charging; is applied.
When the image forming apparatus according to the present embodiment is an intermediate transfer type apparatus, the transfer means transfers, for example, an intermediate transfer body in which a toner image is transferred to the surface and a toner image formed on the surface of the image holder. A configuration having a primary transfer means for primary transfer to the surface of the body and a secondary transfer means for secondary transfer of the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium is applied.

In the image forming apparatus according to the present embodiment, for example, the portion including the developing means may have a cartridge structure (process cartridge) attached to and detached from the image forming apparatus. As the process cartridge, for example, a process cartridge containing a static charge image developer and provided with developing means is preferably used.

Using the image forming apparatus according to the present embodiment, a charging step of charging the surface of the image holder, a static charge image forming step of forming a static charge image on the surface of the charged image holder, and a static charge image developer. A development step of developing a statically charged image formed on the surface of the image holder as a toner image, a transfer step of transferring the toner image formed on the surface of the image holder to the surface of the recording medium, and a transfer step of the recording medium. A fixing process for fixing the toner image transferred to the surface, and a toner replenishment process for replenishing the replenishing toner from the replenishing toner container to the developing means through a toner replenishment path connecting the replenishing toner container and the developing means. The image forming method having, is carried out.

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

FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 1 is a first electrophotographic system that outputs images of each color of yellow (Y), magenta (M), cyan (C), and black (K) based on color-separated image data. A fourth image forming unit 10Y, 10M, 10C, 10K (image forming means) is provided. These image forming units (hereinafter, may be simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged side by side at a predetermined distance from each other in the horizontal direction. These units 10Y, 10M, 10C, and 10K may be process cartridges that are attached to and detached from the image forming apparatus.

Above each unit 10Y, 10M, 10C, and 10K, an intermediate transfer belt (an example of an intermediate transfer body) 20 extends through each unit. The intermediate transfer belt 20 is provided by being wound around the drive roll 22 and the support roll 24, and travels in the direction from the first unit 10Y to the fourth unit 10K. A force is applied to the support roll 24 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 body cleaning device 30 is provided on the side surface of the image holder of the intermediate transfer belt 20 so as to face the drive roll 22.

The image forming apparatus shown in FIG. 1 has a configuration in which toner cartridges 8Y, 8M, 8C, and 8K, which are examples of a replenishing toner container, are attached and detached. The developing devices 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K are connected to the toner cartridges 8Y, 8M, 8C, and 8K by toner supply paths (not shown), respectively. Each color toner is replenished from the toner cartridges 8Y, 8M, 8C, 8K to the developing devices 4Y, 4M, 4C, and 4K through the toner replenishment path. When the amount of toner contained in the toner cartridge is low, the toner cartridge is replaced.

Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration and operation, here, the first unit forming a yellow image arranged on the upstream side in the traveling direction of the intermediate transfer belt. Unit 10Y will be described as a representative.

The first unit 10Y has a photoconductor 1Y that acts as an image holder. Around the photoconductor 1Y, a charging roll (an example of charging means) 2Y that charges the surface of the photoconductor 1Y to a predetermined potential, and a laser beam 3Y based on a color-separated image signal expose the charged surface. An exposure device (an example of a static charge image forming means) 3 for forming an electrostatic charge image, and a developing device (an example of a developing means) 4Y for developing a static charge image by supplying a charged toner to the static charge image. A primary transfer roll 5Y (an example of a primary transfer means) that transfers a toner image onto an intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning means) 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 arranged inside the intermediate transfer belt 20 and is provided at a position facing the photoconductor 1Y. A bias power supply (not shown) for applying a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K of each unit. Each bias power supply changes the value of the transfer bias applied to each primary transfer roll by control by a control unit (not shown).

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

The static charge image is an image formed on the surface of the photoconductor 1Y by charging. The laser beam 3Y reduces the specific resistance of the irradiated portion of the photosensitizer layer, and the charged charge on the surface of the photoconductor 1Y flows. On the other hand, it is a so-called negative latent image formed by the residual charge of the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoconductor 1Y rotates to a predetermined development position as the photoconductor 1Y travels. Then, at this developing position, the electrostatic charge image on the photoconductor 1Y is developed and visualized as a toner image by the developing device 4Y.

In the developing apparatus 4Y, for example, a static charge image developing agent containing at least yellow toner and a carrier is housed. The yellow toner is triboelectrically charged by being agitated inside the developing apparatus 4Y, and has a charge having the same polarity (negative electrode property) as the charged charge on the photoconductor 1Y, and is a developer roll (developing agent holder). Example) It is held on. Then, as the surface of the photoconductor 1Y passes through the developing device 4Y, the yellow toner is electrostatically adhered to the statically eliminated latent image portion on the surface of the photoconductor 1Y, and the latent image is developed by the yellow toner. Toner. The photoconductor 1Y on which the yellow toner image is formed is continuously traveled at a predetermined speed, and the toner image developed on the photoconductor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoconductor 1Y is conveyed to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 5Y, and an electrostatic force from the photoconductor 1Y toward the primary transfer roll 5Y acts on the toner image to expose the toner image. The toner image on the body 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, for example, + 10 μA by a control unit (not shown) in the first unit 10Y.
On the other hand, the toner remaining on the photoconductor 1Y is removed by the photoconductor cleaning device 6Y and recovered.

The primary transfer bias applied to the primary transfer rolls 5M, 5C, and 5K after the second unit 10M is also controlled according to the first unit.
In this way, the intermediate transfer belt 20 on which the yellow toner image is transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of each color are superimposed and multiple-transferred. Will be done.

The intermediate transfer belt 20 in which the toner images of four colors are multiplex-transferred through the first to fourth units includes the intermediate transfer belt 20, the support roll 24 in contact with the inner surface of the intermediate transfer belt, and the image holding surface of the intermediate transfer belt 20. It leads to a secondary transfer unit composed of a secondary transfer roll (an example of the secondary transfer means) 26 arranged on the side. On the other hand, the recording paper (an example of the recording medium) P is fed through the supply mechanism into the gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact with each other at a predetermined timing, and the secondary transfer bias is supported by the support roll. It is applied to 24. The transfer bias applied at this time is (-) polarity, which is the same polarity as the toner polarity (-), and the electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, and the transfer bias is applied on the intermediate transfer belt 20. The toner image of is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by the resistance detecting means (not shown) for detecting the resistance of the secondary transfer unit, and is voltage controlled.

After that, the recording paper P is sent to the pressure contact portion (nip portion) of the pair of fixing rolls in the fixing device (an example of the fixing means) 28, and the toner image is fixed on the recording paper P to form the fixing image. ..

Examples of the recording paper P for transferring the toner image include plain paper used in electrophotographic copiers, printers, and the like. Examples of the recording medium include an OHP sheet and the like in addition to the recording paper P.
In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the recording paper P is also smooth. For example, coated paper in which the surface of plain paper is coated with resin or the like, art paper for printing, or the like is used. Suitable for use.

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

FIG. 2 is a schematic configuration diagram showing an example of an image holder, a developing means, a toner replenishment path, and a replenishment toner container included in the image forming apparatus according to the present embodiment.

The configuration example shown in FIG. 2 includes a photoconductor 102, which is an example of an image holder, a developing device 104, which is an example of developing means, a toner replenishment path 200, and a replenishment toner container 300. In the following description, the upstream side of the toner supply path 200 means the upstream side in the toner movement direction, and the downstream side of the toner supply path 200 means the downstream side in the toner movement direction.

The replenishment toner container 300 internally stores a specific toner, which will be described later, as a replenishment toner to be replenished to the developing apparatus 104. The replenishment toner container 300 is, for example, a toner cartridge that can be attached to and detached from the image forming apparatus. The toner contained in the replenishment toner container 300 is discharged from the replenishment toner container 300 to the toner replenishment path 200 by, for example, free fall. The replenishment toner container 300 may include an August cru that conveys toner inside.

The toner supply path 200 includes a toner container mounting portion 202, an air supply port 204, a screw pump 206, and a toner transport pipe 208 in this order from the upstream side. The toner container mounting unit 202 is connected to the replenishment toner container 300, and the toner transport tube 208 is connected to the developing device 104.

The toner container mounting unit 202 is a portion for mounting the replenishing toner container 300 on the image forming apparatus in a detachable manner. The toner container mounting portion 202 is provided with a toner receiving port connected to a toner discharging port of the replenishing toner container 300. The replenishment toner container 300 is mounted on the toner container mounting portion 202, for example, along the major axis direction in the vertical direction.

The air supply port 204 is a means for sending air to the toner in order to fluidize the toner. Air is sent to the air supply port 204 from, for example, an air pump (not shown). The air supply from the air supply port 204 may be continuous or intermittent. The amount of air supplied from the air supply port 204 is, for example, 8 mL / s or more and 35 mL / s or less.

The screw pump 206 is, for example, a rotary positive displacement uniaxial eccentric screw pump as shown in FIG. The screw pump 206 includes, for example, a stator 206a having two spiral grooves formed inside a metal outer cylinder, and a rotor 206b rotatably arranged in the stator 206a. The rotor 206b is rotationally driven by a drive device (not shown).
The material of the stator 206a is, for example, an elastic body, and examples of the elastic body include nitrile butadiene rubber, ethylene propylene rubber, silicone rubber, and urethane rubber. The material of the rotor 206b is, for example, stainless steel.
The toner discharge rate of the screw pump 206 is, for example, 5 g / min or more and 80 g / min or less.

The toner transport pipe 208 is a pipe that connects the screw pump 206 and the developing device 104. The material of the toner transport tube 208 may be an elastic body such as rubber or an inelastic body such as metal. The toner that has been fluidized by air being sent through the air supply port 204 moves through the toner transport pipe 208 by driving the screw pump 206.

The developing apparatus 104 is divided into, for example, two chambers by a partition member, one chamber is provided with an outlet of a toner supply path 200, and the other chamber is provided with a developing roll facing the photoconductor 102. ing. The two chambers are partially connected, and each chamber is provided with one stirring member for transporting the developer while stirring. The developer (not shown) in the developing apparatus 104 is conveyed while being stirred by the two stirring members and supplied to the developing roll.

The image forming apparatus includes a control unit (not shown) that exchanges information with each device (each unit) and controls the operation of each device (each unit). For example, the developing apparatus 104 is provided with a developing agent amount detecting means (not shown), and when the developing agent amount detecting means detects an insufficient amount of the developing agent, a control unit (not shown) drives a screw pump 206. Emit. When the screw pump 206 is driven, the toner moves in the toner supply path 200 and is supplied to the developing device 104. Further, for example, a toner remaining amount detecting means (not shown) is provided in the replenishing toner container 300, and when the toner remaining amount detecting means detects the insufficient amount of the toner remaining amount, the replenishing toner is stored in a display unit (not shown). A replacement instruction for the vessel 300 is displayed.

The control unit (not shown) is configured as a computer that controls the entire device and performs various calculations. Specifically, for example, the control unit includes a CPU (Central Processing Unit; Central Processing Unit), a ROM (Read Only Memory) that stores various programs, and a RAM (Random Access) that is used as a work area when executing the programs. Memory), a non-volatile memory for storing various information, and an input / output interface (I / O) (all not shown). Each of the CPU, ROM, RAM, non-volatile memory, and I / O is connected via a bus.

The image forming apparatus includes an operation display unit, an image processing unit, an image memory, a storage unit, a communication unit, and the like in addition to the control unit (all of which are not shown). Each unit of the operation display unit, the image processing unit, the image memory, the storage unit, and the communication unit is connected to the I / O of the control unit. The control unit (not shown) controls each unit by exchanging information with each unit of the operation display unit, the image processing unit, the image memory, the storage unit, and the communication unit.

<Replenishment toner>
The replenishing toner applied to the image forming apparatus according to the present embodiment will be described in detail. The toner may be used as a toner preloaded in the developing means.

The replenishment toner has toner particles and a number average particle diameter of 110 nm or more and 130 nm or less, a large diameter side number particle size distribution index (upper GSDp) of less than 1.080, and an average circularity of 0.94 or more and 0. It contains silica particles having a degree of 98 or less and a degree of circularity of 0.92 or more of 80% by number or more.

[Toner particles]
The toner particles are composed of, for example, a binder resin,, if necessary, a colorant, a mold release agent, and other additives.

-Bound resin-
Examples of the binder resin include styrenes (for example, styrene, parachlorostyrene, α-methylstyrene, etc.) and (meth) acrylic acid esters (for example, 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 (eg, acrylonitrile, Methacrylic acid, 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, butadiene, etc.), etc. Examples thereof include a homopolymer of the above-mentioned monomer and a vinyl-based resin composed of a copolymer obtained by combining two or more kinds of these monomers.
Examples of the binder resin include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures of these with the vinyl resins, or these. Examples thereof include a graft polymer obtained by polymerizing a vinyl-based monomer in the coexistence.
These binder resins may be used alone or in combination of two or more.

(1) Styrene Acrylic Resin As the binder resin, styrene acrylic resin is suitable.
The styrene acrylic resin contains a styrene-based monomer (a monomer having a styrene skeleton) and a (meth) acrylic-based monomer (a monomer having a (meth) acryloyl group, preferably a (meth) acryloyl oxy group. It is a copolymer obtained by at least copolymerizing with (a monomer having). The styrene acrylic resin contains, for example, a copolymer of a styrene monomer and the above-mentioned (meth) acrylic acid ester monomer. The acrylic resin portion of the styrene acrylic resin has a partial structure formed by polymerizing either an acrylic monomer or a methacrylic monomer, or both. Further, "(meth) acrylic" is an expression including both "acrylic" and "methacryl".

Specific examples of the styrene-based monomer include styrene and alkyl-substituted styrene (for example, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene). Ethylstyrene, 4-ethylstyrene, etc.), halogen-substituted styrene (for example, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, etc.), vinylnaphthalene, and the like can be mentioned. The styrene-based monomer may be used alone or in combination of two or more.
Among these, as the styrene-based monomer, styrene is preferable in terms of ease of reaction, ease of control of reaction, and availability.

Specific examples of the (meth) acrylic monomer include (meth) acrylic acid and (meth) acrylic acid ester. Examples of the (meth) acrylic acid ester include (meth) acrylic acid alkyl ester (for example, methyl (meth) acrylic acid, ethyl (meth) acrylic acid, n-propyl (meth) acrylic acid, n (meth) acrylic acid. -Butyl, n-pentyl (meth) acrylate, n-hexyl acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acrylate n-dodecyl, 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, neopentyl (meth) acrylate, isohexyl (meth) acrylate, isoheptyl (meth) acrylate, (meth) ) Isooctyl acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, etc.), aryl (meth) acrylate (eg, phenyl (meth) acrylate, Biphenyl (meth) acrylate, diphenylethyl (meth) acrylate, t-butylphenyl (meth) acrylate, tarphenyl (meth) acrylate, etc.), dimethylaminoethyl (meth) acrylate, diethylamino (meth) acrylate Examples thereof include ethyl, methoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, β-carboxyethyl (meth) acrylate, and (meth) acrylamide. The (meth) acrylic acid-based monomer may be used alone or in combination of two or more.
Among the (meth) acrylic monomers, among these (meth) acrylic esters, from the viewpoint of enhancing the fixability of the toner, the number of carbon atoms is 2 or more and 14 or less (preferably 2 or more and 10 or less carbon atoms, more preferably 3). A (meth) acrylic acid ester having an alkyl group (8 or less) is preferable. Of these, n-butyl (meth) acrylate is preferable, and n-butyl acrylate is particularly preferable.

The copolymerization ratio of the styrene-based monomer and the (meth) acrylic-based monomer (mass basis, styrene-based monomer / (meth) acrylic-based monomer) is not particularly limited, but is 85/15 or more. It is preferably 60/40.

The styrene acrylic resin preferably has a crosslinked structure. The styrene acrylic resin having a crosslinked structure is preferably, for example, one obtained by at least copolymerizing a styrene-based monomer, a (meth) acrylic acid-based monomer, and a crosslinkable monomer.

Examples of the crosslinkable monomer include a bifunctional or higher functional crosslinker.
Examples of the bifunctional cross-linking agent include divinylbenzene, divinylnaphthalene, and di (meth) acrylate compounds (for example, diethylene glycol di (meth) acrylate, methylenebis (meth) acrylamide, decanediol diacrylate, glycidyl (meth) acrylate, etc.). , Polyester type di (meth) acrylate, 2-([1'-methylpropylideneamino] carboxyamino) ethyl methacrylate and the like.
Examples of the trifunctional or higher functional cross-linking agent include tri (meth) acrylate compounds (for example, pentaerythritol tri (meth) acrylate, trimethylolethanetri (meth) acrylate, trimethylolpropane tri (meth) acrylate, etc.) and tetra (meth). Acrylate compounds (eg, pentaerythritol tetra (meth) acrylate, oligoester (meth) acrylate, etc.), 2,2-bis (4-methacryloxy, polyethoxyphenyl) propane, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate. , Triaryltrimethylate, diallyl chlorendate and the like.
Among them, as the crosslinkable monomer, a bifunctional or higher functional (meth) acrylate compound is preferable, and a bifunctional (meth) acrylate compound is more preferable, and an alkylene group having 6 to 20 carbon atoms is preferable from the viewpoint of enhancing the fixability of the toner. A bifunctional (meth) acrylate compound having the above is more preferable, and a bifunctional (meth) acrylate compound having a linear alkylene group having 6 to 20 carbon atoms is particularly preferable.

The copolymerization ratio of the crosslinkable monomer to all the monomers (mass basis, crosslinkable monomer / total monomer) is not particularly limited, but is 2 / 1,000 to 20 / 1,000. Is preferable.

The glass transition temperature (Tg) of the styrene acrylic resin is preferably 40 ° C. or higher and 75 ° C. or lower, and more preferably 50 ° C. or higher and 65 ° C. or lower, from the viewpoint of enhancing the fixability of the toner.
The glass transition temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, described in "Method for measuring the transition temperature of plastics" in JIS K 7121-1987. It is determined by the "external glass transition start temperature".

The weight average molecular weight of the styrene acrylic resin is preferably 5,000 or more and 200,000 or less, more preferably 10,000 or more and 100,000 or less, and 20,000 or more and 80,000 or less from the viewpoint of toner storage stability. Especially preferable.

The method for producing the styrene acrylic resin is not particularly limited, and various polymerization methods (for example, solution polymerization, precipitation polymerization, suspension polymerization, bulk polymerization, emulsion polymerization, etc.) are applied. Further, a known operation (for example, batch type, semi-continuous type, continuous type, etc.) is applied to the polymerization reaction.

(2) Polyester resin As the binder resin, polyester resin is suitable.
Examples of the polyester resin include known amorphous polyester resins. As the polyester resin, a crystalline polyester resin may be used in combination with the amorphous polyester resin. However, the crystalline polyester resin may be used in a range of 2% by mass or more and 40% by mass or less (preferably 2% by mass or more and 20% by mass or less) with respect to the total binder resin.

The "crystallinity" of a resin means that in differential scanning calorimetry (DSC), it has a clear endothermic peak rather than a stepwise endothermic change, and specifically, the temperature rise rate is 10 (° C./min). ) Indicates that the half-value width of the endothermic peak is within 10 ° C.
On the other hand, "amorphous" of the resin means that the half width exceeds 10 ° C., shows a stepwise endothermic amount change, or does not show a clear endothermic peak.

-Amorphous polyester resin Examples of the amorphous polyester resin include a condensed polymer of a polyvalent carboxylic acid and a polyhydric alcohol. As the amorphous polyester resin, a commercially available product may be used, or a synthetic resin may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, 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 acid (eg cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acid (eg, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), these anhydrides, or their lower grades (eg, 1 or more carbon atoms). 5 or less) Alkyl ester can be mentioned. Among these, as the polyvalent carboxylic acid, for example, an aromatic dicarboxylic acid is preferable.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include aliphatic diols (eg, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (eg, cyclohexanediol, cyclohexanedimethanol, etc.). Hydrogenated bisphenol A, etc.), aromatic diols (for example, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, etc.) can be mentioned. Among these, as the polyhydric alcohol, for example, an aromatic diol and an alicyclic diol are preferable, and an aromatic diol is more preferable.
As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
The polyhydric alcohol may be used alone or in combination of two or more.

The glass transition temperature (Tg) of the amorphous 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 obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, described in "Method for measuring the transition temperature of plastics" in JIS K 7121-1987. It is determined by the "external glass transition start temperature".

The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less.
The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2000 or more and 100,000 or less.
The molecular weight distribution Mw / Mn of the amorphous 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 using a Tosoh GPC / HLC-8120GPC as a measuring device, a Tosoh column / TSKgel SuperHM-M (15 cm), and a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

The amorphous polyester resin is obtained by a known production method. Specifically, for example, the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the pressure inside the reaction system is reduced as necessary, and the reaction is carried out while removing water and alcohol generated during condensation.
When the raw material monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a dissolution aid to dissolve the raw material. In this case, the polycondensation reaction is carried out while distilling off the dissolution aid. When a monomer having poor compatibility is present, it is advisable to condense the monomer having poor compatibility with the monomer and an acid or alcohol to be polycondensed in advance, and then polycondensate with the main component. ..

-Crystalline polyester resin Examples of the crystalline polyester resin include a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. As the crystalline polyester resin, a commercially available product may be used, or a synthetic resin may be used.
Here, since the crystalline polyester resin easily forms a crystal structure, a polycondensate using a polymerizable monomer having a linear aliphatic is preferable to a polymerizable monomer having an aromatic.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonandicarboxylic acid, and 1,10-decandicarboxylic acid. Acids, 1,12-dodecanedicarboxylic acids, 1,14-tetradecandicarboxylic acids, 1,18-octadecanedicarboxylic acids, etc., aromatic dicarboxylic acids (eg, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid) Examples thereof include dibasic acids such as acids), anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent carboxylic acid include aromatic carboxylic acids (for example, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.). Anhydrides or lower (for example, 1 to 5 carbon atoms) alkyl esters thereof can be mentioned.
As the polyvalent carboxylic acid, a dicarboxylic acid having a sulfonic acid group and a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include an aliphatic diol (for example, a linear aliphatic diol having 7 or more and 20 or less carbon atoms in the main chain portion). Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and 1,8-. Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Examples thereof include octadecanediol and 1,14-eicosanedecanediol. Among these, as the aliphatic diol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable.
As the polyhydric alcohol, a trihydric or higher alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like.
The polyhydric alcohol may be used alone or in combination of two or more.

Here, the polyhydric alcohol preferably has an aliphatic diol content of 80 mol% or more, preferably 90 mol% or more.

The melting temperature of the crystalline polyester resin is preferably 50 ° C. or higher and 100 ° C. or lower, more preferably 55 ° C. or higher and 90 ° C. or lower, and further preferably 60 ° C. or higher and 85 ° C. or lower.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for determining the melting temperature in JIS K7121-1987 "Method for measuring transition temperature of plastics".

The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

The crystalline polyester resin can be obtained by a known production method, like, for example, an amorphous polyester.

The content of the binder resin is, for example, preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and 60% by mass or more and 85% by mass or less with respect to the entire toner particles. More preferred.

-Colorant-
Examples of colorants include carbon black, chrome yellow, Hansa yellow, benzine yellow, slene yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, and brilliant. Carmin 6B, Dupont Oil Red, Pyrazolon Red, Resole Red, Rhodamin B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultra Marine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or aclysine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black Examples thereof include various dyes such as system, polymethine type, triphenylmethane type, diphenylmethane type and thiazole type.
The colorant may be used alone or in combination of two or more.

As the colorant, a surface-treated colorant may be used if necessary, or may be used in combination with a dispersant. Further, a plurality of kinds 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.

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

-Release agent-
Examples of the release agent include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; 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) by the "melting peak temperature" described in the method for determining the melting temperature in JIS K 7121-1987 "Method for measuring transition temperature of plastics".

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

-Other additives-
Examples of other additives include known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are contained in the toner particles as an internal additive.

-Characteristics of toner particles, etc.-
The toner particles may be toner particles having a single layer structure, or are toner particles having a so-called core-shell structure composed of a core portion (core particles) and a coating layer (shell layer) covering the core portion. You may.
Here, the toner particles having a core-shell structure include, for example, a core portion composed of a binder resin and, if necessary, other additives such as a colorant and a mold release agent, and a binder resin. It is preferably composed of a composed 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.

Various average particle diameters of toner particles and various particle size distribution indexes are measured using Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolytic solution is measured using ISOTON-II (manufactured by Beckman Coulter).
At the time of measurement, 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolytic solution 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 or more and 60 μm or less is obtained by using a 100 μm aperture with a Coulter Multisizer II. Measure. The number of particles to be sampled is 50,000.
Draw a cumulative distribution of volume and number from the small diameter side for each particle size range (channel) divided based on the measured particle size distribution, and the particle size that becomes a cumulative 16% is the volume particle size D16v, several particle size. The particle size with D16p and cumulative 50% is defined as volume average particle size D50v, cumulative number average particle size D50p, and the particle size with cumulative 84% is defined as volume particle size D84v and several particle size D84p.
Using these, the volume particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 , and the number particle size distribution index (GSDp) is calculated as ^{(D84p / D16p) 1/2.}

The average circularity of the toner particles is preferably 0.94 or more and 1.00 or less, and more preferably 0.95 or more and 0.98 or less.

The average circularity of the toner particles is obtained by (circumferential peripheral length) / (circumferential length) [(circumferential length of a circle having the same projected area as the particle image) / (peripheral length of the particle projected image)]. Specifically, it is a value measured by the following method.
First, a flow-type particle image analyzer (Cysmex) that captures a particle image as a still image by sucking and collecting toner particles to be measured, forming a flat flow, and instantly causing strobe light emission to analyze the particle image. Obtained by FPIA-3000) manufactured by the company. Then, the number of samples for obtaining the average circularity is set to 3500.
When the toner has an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant, and then ultrasonic treatment is performed to obtain toner particles from which the external additive has been removed.

<First silica particles>
The replenishment toner has a number average particle size of 110 nm or more and 130 nm or less, a large diameter side number particle size distribution index (upper GSDp) of less than 1.080, and an average circularity of 0.94 or more and 0.98 or less. In addition, silica particles having a circularity of 0.92 or more and a ratio of 80% by number or more (also referred to as “first silica particles” in the present disclosure) are included.

The number average particle size of the first silica particles is 110 nm or more and 130 nm or less, and is 113 nm or more and 127 nm or less from the viewpoint of suppressing the occurrence of fog in a low temperature and low humidity environment and the decrease in image density in a high temperature and high humidity environment. It is preferably 115 nm or more and 125 nm or less, more preferably.

The method for setting the number average particle diameter of the first silica particles within the above range is not particularly limited. For example, the first silica particles are sol-gel silica particles, and in the production of the sol-gel silica particles, an alkali catalyst and tetraalkoxysilane are used. Examples thereof include a method of adjusting the temperature or reaction time at the time of mixing; a method of adjusting the concentrations of the alkali catalyst and the tetraalkoxysilane; and the like.

The large-diameter side number particle size distribution index (upper GSDp) of the first silica particles is less than 1.080, and from the viewpoint of suppressing the occurrence of fog in a low-temperature and low-humidity environment and the decrease in image density in a high-temperature and high-humidity environment, 1 It is preferably less than .077, more preferably less than 1.075.

The small-diameter side number particle size distribution index (lower GSDp) of the first silica particles is less than 1.080 from the viewpoint of suppressing the occurrence of fog in a low-temperature and low-humidity environment and the decrease in image density in a high-temperature and high-humidity environment. It is preferably less than 1.077, more preferably less than 1.075.

The method of setting the upper GSDp and the lower GSDp of the first silica particles within the above ranges is not particularly limited. For example, the first silica particles are sol-gel silica particles, and in the production of the sol-gel silica particles, an alkali catalyst and tetraalkoxysilane are used. A method of adjusting the temperature or reaction time when mixing with and the like; a method of adjusting the concentration of the alkali catalyst and the tetraalkoxysilane; and the like can be mentioned.

The number average particle diameter of the first silica particles, the upper GSDp and the lower GSDp are obtained as follows.
(1) The toner is dispersed in methanol, stirred at room temperature (23 ° C.), and then treated with an ultrasonic bath to separate the external additive from the toner. Subsequently, the toner particles are precipitated by centrifugation, and the dispersion liquid in which the external additive is dispersed is recovered. Then, methanol is distilled off and the external additive is taken out.
(2) The external additive is dispersed in resin particles (polyester, weight average molecular weight Mw = 50,000) having a volume average particle diameter of 100 μm.
(3) A scanning electron microscope (SEM) (Hitachi) equipped with an energy dispersive X-ray analyzer (EDX device) (HORIBA, Ltd., EMAX Evolution X-Max80mm ^{2) on the resin particles in which the external additive is dispersed.} Observe using S-4800, manufactured by Hitachi High-Technologies, and take an image at a magnification of 40,000 times. At this time, 300 or more primary silica particles are identified from within one field of view based on the presence of Si by EDX analysis. The SEM is observed at an acceleration voltage of 15 kV, an emission current of 20 μA, and a WD of 15 mm, and the EDX analysis is performed under the same conditions with a detection time of 60 minutes.
(4) The obtained image is taken into an image analysis device (LUZEXIII, manufactured by Nireco Corporation), and the area of each particle is determined by image analysis.
(5) From this measured area value, the particle size of silica is determined as the equivalent circle diameter.
(6) 100 silica particles having a circle-equivalent diameter of 80 nm or more are selected.

For the selected silica particles, the cumulative distribution of the equivalent circle diameter is drawn from the small diameter side, and the particle diameter at which the cumulative diameter is 50% is defined as the number average particle diameter of the first silica particles.
For the selected silica particles, the cumulative distribution of the equivalent circle diameter is drawn from the small diameter side, and the particle size with a cumulative total of 16% is the number particle size D16p, and the particle size with a cumulative 50% is the number average particle size D50p, cumulative 84%. The particle size is defined as the number particle size D84p. The large-diameter side number particle size distribution index (upper GSDp) is calculated as (D84p / D50p) ^1/2 , and the small-diameter side number particle size distribution index (lower GSDp) is calculated as ^{(D50p / D16p) 1/2.} ..

The average circularity of the first silica particles is 0.94 or more and 0.98 or less, and is 0.940 or more and 0 from the viewpoint of suppressing the occurrence of fog in a low temperature and low humidity environment and the decrease in image density in a high temperature and high humidity environment. It is preferably .980 or less, more preferably 0.945 or more and 0.975 or less, and further preferably 0.950 or more and 0.970 or less.

The method for setting the average circularity of the first silica particles within the above range is not particularly limited. For example, the first silica particles are sol-gel silica particles, and an alkali catalyst and tetraalkoxysilane are mixed in the production of the sol-gel silica particles. A method of adjusting the temperature or the reaction time at the time of the operation; a method of adjusting the concentration of the alkali catalyst; and the like can be mentioned.

The proportion of silica particles having a circularity of 0.92 or more in the first silica particles is 80% or more, and is 85 from the viewpoint of suppressing the occurrence of fog in a low temperature and low humidity environment and the decrease in image density in a high temperature and high humidity environment. The number is preferably% or more, and more preferably 87% or more.

The method of setting the ratio of the silica particles having a circularity of 0.92 or more in the first silica particles to the above range is not particularly limited. For example, the first silica particles are sol-gel silica particles, and in the production of the sol-gel silica particles, alkali. Examples thereof include a method of adjusting the temperature or reaction time when the catalyst and the tetraalkoxysilane are mixed; a method of adjusting the concentration of the alkali catalyst; and the like.

The average circularity of the first silica particles and the ratio of the silica particles having a circularity of 0.92 or more in the first silica particles are determined as follows.
For 100 particles selected in the above-mentioned method for determining the number average particle size of the first silica particles, each circularity is calculated by the following formula (1). The frequency of 50% circularity accumulated from the small diameter side of the obtained circularity is defined as the average circularity of the first silica particles.
Equation (1): Circularity = 4π × (A / I ² )
In the formula (1), I represents the peripheral length of the primary particle on the image, and A represents the projected area of the primary particle.
Further, the number ratio of the circularity of 0.92 or more in each of the 100 circularities when the average circularity is calculated is defined as the number ratio of the silica particles having a circularity of 0.92 or more in the first silica particles. ..

The degree of hydrophobization of the first silica particles is preferably 50% or more and 80% or less, preferably 50% or more and 75% or more, from the viewpoint of suppressing the occurrence of fog in a low temperature and low humidity environment and the decrease in image density in a high temperature and high humidity environment. It is more preferably% or less, and further preferably 50% or more and 70% or less.

The method for setting the degree of hydrophobicity of the first silica particles within the above range is not particularly limited. For example, the first silica particles are sol-gel silica particles, and in the production of the sol-gel silica particles, silica is present in the presence of supercritical carbon dioxide. A method of hydrophobizing the surface of particles with a hydrophobizing agent: and the like.

The degree of hydrophobization of the first silica particles is determined as follows.
0.2% by mass of silica particles as a sample is added to 50 ml of ion-exchanged water, and methanol is added dropwise from the burette while stirring with a magnetic stirrer. At this time, the methanol mass fraction (%) (= methanol addition amount / (methanol addition amount + ion exchange water amount)) in the methanol-ion exchange water mixed solution at the end point where the entire sample amount is submerged in the solution is hydrophobic. Obtained as the degree of conversion (%).

The first silica particles may be silica, that is, particles _{containing SiO 2} as a main component, and may be either crystalline or amorphous. The first silica particles may be particles produced from a silicon compound such as water glass or alkoxysilane, or may be particles obtained by pulverizing quartz. Examples of the first silica particles include solgel silica particles; aqueous colloidal silica particles; alcoholic silica particles; fumed silica particles obtained by a vapor phase method and the like; molten silica particles; and the like. Among the above, the first silica particles preferably contain sol-gel silica particles.

Sol-gel silica particles are obtained, for example, as follows. Tetraalkoxysilane (TMS, etc.) is added dropwise to an alkaline catalyst solution containing an alcohol compound and aqueous ammonia, and tetraalkoxysilane is hydrolyzed and condensed to obtain a suspension containing sol-gel silica particles. The solvent is then removed from the suspension to give the granules. The granules are then dried to give sol-gel silica particles.

The first silica particles may be silica particles that have been hydrophobized with a hydrophobizing agent.
Examples of the hydrophobizing agent include known organic silicon compounds having an alkyl group (for example, methyl group, ethyl group, propyl group, butyl group, etc.), and specific examples thereof include an alkoxysilane compound, a siloxane compound, and silazane. Examples include compounds. Among the above, the hydrophobizing agent preferably contains at least one of a siloxane compound and a silazane compound. The hydrophobizing agent may be used alone or in combination of two or more.

Examples of the siloxane compound include silicone oil and silicone resin. The silicone oil preferably contains dimethyl silicone oil. The siloxane compound may be used alone or in combination of two or more.
Examples of the silazane compound include hexamethyldisilazane and tetramethyldisilazane. Among the above, the silazane compound preferably contains hexamethyldisilazane (HMDS). The silazane compound may be used alone or in combination of two or more.

The amount of the hydrophobizing agent such as a silazane compound adhering to the surface of the first silica particles is 0.01% by mass with respect to the first silica particles from the viewpoint of improving the degree of hydrophobicity of the first silica particles. It is preferably 5% by mass or less, more preferably 0.05% by mass or more and 3% by mass or less, and further preferably 0.10% by mass or more and 2% by mass or less.

As a method of hydrophobizing the first silica particles with a hydrophobizing agent, for example, using supercritical carbon dioxide, the hydrophobizing agent is dissolved in the supercritical carbon dioxide, and the surface of the silica particles is hydrophobic. Method of attaching the chemical treatment agent; In the air, a solution containing the hydrophobic treatment agent and a solvent for dissolving the hydrophobic treatment agent is applied to the surface of the silica particles (for example, spraying or coating) to make the surface of the silica particles hydrophobic. Method of attaching the chemical treatment agent; In the air, a solution containing the hydrophobic treatment agent and a solvent for dissolving the hydrophobic treatment agent is added and held in the silica particle dispersion, and then the silica particle dispersion and the solution are maintained. A method of drying the mixed solution of the above;

<Other external additives>
The replenishing toner may further contain other external additives other than the first silica particles (hereinafter, also simply referred to as “other external agents”). Examples of other external additives include inorganic oxide particles. Examples of the inorganic oxide particles include 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. Among the above, the inorganic oxide particles preferably include TiO ₂ , SiO ₂ , that is, titania particles or silica particles (hereinafter, also referred to as “second silica particles”).

The number average particle size of the inorganic oxide particles is preferably 5 nm or more and 50 nm or less, more preferably 9 nm or more and 50 nm or less, and further preferably 10 nm or more and 40 nm or less from the viewpoint of enhancing the fluidity of the toner. It is preferable, and it is more preferably 10 nm or more and 30 nm or less.

The average particle size of the number of inorganic oxide particles is determined as follows.
(1) The toner is dispersed in methanol, stirred at room temperature (23 ° C.), and then treated with an ultrasonic bath to separate the external additive from the toner. Subsequently, the toner particles are precipitated by centrifugation, and the dispersion liquid in which the external additive is dispersed is recovered. Then, methanol is distilled off and the external additive is taken out.
(2) The external additive is dispersed in resin particles (polyester, weight average molecular weight Mw = 50,000) having a volume average particle diameter of 100 μm.
(3) A scanning electron microscope (SEM) (Hitachi) equipped with an energy dispersive X-ray analyzer (EDX device) (HORIBA, Ltd., EMAX Evolution X-Max80mm ^{2) on the resin particles in which the external additive is dispersed.} Observe using S-4800, manufactured by Hitachi High-Technologies, and take an image at a magnification of 40,000 times. At this time, 300 or more primary particles of the inorganic oxide particles are identified from one field of view based on the presence of atoms (Si, Ti, etc.) contained in each inorganic oxide particle by EDX analysis. The SEM is observed at an acceleration voltage of 15 kV, an emission current of 20 μA, and a WD of 15 mm, and the EDX analysis is performed under the same conditions with a detection time of 60 minutes.
(4) The obtained image is taken into an image analysis device (LUZEXIII, manufactured by Nireco Corporation), and the area of each particle is determined by image analysis.
(5) From this measured area value, the particle size of each inorganic oxide particle is determined as the equivalent circle diameter.
(6) Select 100 particles having a circle-equivalent diameter of less than 80 nm. For the selected particles, the cumulative distribution of the equivalent circle diameter is drawn from the small diameter side, and the particle diameter at which the cumulative diameter is 50% is defined as the number average particle diameter of the inorganic oxide particles.

The content of the inorganic oxide particles contained in the toner is higher than the content of the first silica particles contained in the toner from the viewpoint of suppressing the occurrence of fog in a low temperature and low humidity environment and the decrease in image density in a high temperature and high humidity environment. It is preferable that the amount is small. More specifically, the content of the inorganic oxide particles is preferably 20 parts by mass or more and 80 parts by mass or less, preferably 30 parts by mass or more, with respect to 100 parts by mass of the content of the first silica particles contained in the toner. It is more preferably 70 parts by mass or less.

The ratio Da / Db of the number average particle size Da (nm) of the first silica particles to the number average particle size Db (nm) of the inorganic oxide particles is the occurrence of fog in a low temperature and low humidity environment and the image density in a high temperature and high humidity environment. From the viewpoint of suppressing the decrease in the amount of particles, it is preferably 2.0 or more and 35 or less, more preferably 2.1 or more and 32 or less, further preferably 2.2 or more and 30 or less, and 2.5. It is more preferably 20 or less.

The surface of the inorganic oxide particles as an external additive should be hydrophobized. The hydrophobizing treatment is performed, for example, by immersing the inorganic oxide particles in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include a silane-based coupling agent, a silicone oil, a titanate-based coupling agent, and an aluminum-based coupling agent. These may be used alone or in combination of two or more.
The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic oxide particles.

Examples of the external additive include resin particles (resin particles such as polystyrene, polymethylmethacrylate (PMMA), and melamine resin), cleaning active agents (for example, particles of a fluoropolymer) and the like.

The amount of the external additive added is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.01% by mass or more and 2.0% by mass or less, based on the toner particles, for example.

[Toner manufacturing method]
The toner according to the present embodiment can be 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 agglomeration coalescence method, a suspension polymerization method, a dissolution suspension method, etc.). These manufacturing methods are not particularly limited, and known manufacturing methods are adopted. Among these, it is preferable to obtain toner particles by the aggregation and coalescence method.

Specifically, for example, when the toner particles are produced by the aggregation and coalescence method, a step of preparing a resin particle dispersion liquid in which resin particles to be a binder resin are dispersed (resin particle dispersion liquid preparation step) and a step of preparing the resin particles A step of aggregating resin particles (other particles if necessary) in a dispersion (in a dispersion after mixing other particle dispersions if necessary) to form agglomerated particles (aggregated particle formation). Toner particles are manufactured through a step (step) and a step of heating the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed and fusing and coalescing the agglomerated particles to form toner particles (fusing and coalescing step). To do.

The details of each step will be described below.
In the following description, a method for obtaining toner particles containing a colorant and a release agent will be described, but the colorant and the release agent are used as needed. Of course, other additives other than colorants and mold release agents may be used.

-Resin particle dispersion liquid preparation process-
Along with the resin particle dispersion liquid in which the resin particles to be the binder resin are dispersed, for example, a colorant particle dispersion liquid in which the colorant particles are dispersed and a release agent particle dispersion liquid in which the release agent particles are dispersed are prepared.

The resin particle dispersion liquid is prepared, for example, by dispersing the resin particles in a dispersion medium with a surfactant.

Examples of the dispersion medium used in the resin particle dispersion liquid include an aqueous medium.
Examples of the aqueous medium include distilled water, water such as ion-exchanged water, alcohols, and the like. These may be used alone or in combination of two or more.

Examples of the surfactant include anionic surfactants such as sulfate ester type, sulfonate type, phosphoric acid ester type and soap type; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol. Examples thereof include nonionic surfactants such as systems, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
The surfactant may be used alone or in combination of two or more.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion liquid include general dispersion methods such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Further, depending on the type of resin particles, the resin particles may be dispersed in a dispersion medium by a phase inversion emulsification method. In the phase inversion emulsification method, a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and a base is added to an organic continuous phase (O phase) to neutralize the resin, and then an aqueous medium (W phase) is used. ) Is added to perform phase inversion from W / O to O / W, and the resin is dispersed in an aqueous medium in the form of particles.

The volume average particle diameter of the resin particles dispersed in the resin particle dispersion is, for example, preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, and further preferably 0.1 μm or more and 0.6 μm or less. preferable.
The volume average particle size of the resin particles is determined by using the particle size distribution obtained by the measurement of a laser diffraction type particle size distribution measuring device (for example, LA-700 manufactured by Horiba Seisakusho) with respect to the divided particle size range (channel). The cumulative distribution is subtracted from the small particle size side, and the particle size that is cumulatively 50% of all particles is measured as the volume average particle size D50v. The volume average particle size of the particles in the other dispersions is measured in the same manner.

The content of the resin particles contained in the resin particle dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

Similar to the resin particle dispersion, for example, a colorant particle dispersion and a release agent particle dispersion are also prepared. That is, regarding the volume average particle size, the dispersion medium, the dispersion method, and the content of the particles in the resin particle dispersion liquid, the colorant particles dispersed in the colorant particle dispersion liquid and the release agent particle dispersion liquid are used. The same applies to the disperse of the release agent particles.

-Agglomerated particle formation process-
Next, the resin particle dispersion liquid, the colorant particle dispersion liquid, and the release agent particle dispersion liquid are mixed.
Then, in the mixed dispersion, the resin particles, the colorant particles, and the release agent particles are heteroaggregated to form the resin particles, the colorant particles, and the release agent particles having a diameter close to the diameter of the target toner particles. Form agglomerated particles containing.

Specifically, for example, a flocculant is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to acidic (for example, pH 2 or more and 5 or less), a dispersion stabilizer is added as necessary, and then the resin particles. (Specifically, for example, the glass transition temperature of the resin particles is -30 ° C or higher and the glass transition temperature is -10 ° C or lower), and the particles dispersed in the mixed dispersion are aggregated. Form agglomerated particles.
In the agglomerated particle forming step, for example, the mixed dispersion is stirred with a rotary shear type homogenizer, and an aggregating agent is added at room temperature (for example, 25 ° C.) to adjust the pH of the mixed dispersion to acidic (for example, pH 2 or more and 5 or less). Then, if necessary, heating may be performed after adding the dispersion stabilizer.

Examples of the flocculant include a surfactant having a polarity opposite to that of the surfactant contained in the mixed dispersion, an inorganic metal salt, and a divalent or higher valent metal complex. When a metal complex is used as the flocculant, the amount of the surfactant used is reduced and the charging characteristics are improved.
An additive that forms a complex or similar bond with the metal ion of the flocculant may be used together with the flocculant, if necessary. As this additive, a chelating agent is preferably used.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride and aluminum sulfate; and inorganic metal salts such as polyaluminum chloride, polyaluminum hydroxide and calcium polysulfide. Polymers; and the like.
As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid and gluconic acid; aminocarboxylic acids such as iminodioic acid vinegar (IDA), nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA); Be done.
The amount of the chelating agent added is preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass with respect to 100 parts by mass of the resin particles.

-Fusion / unification process-
Next, the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed is heated to, for example, a temperature equal to or higher than the glass transition temperature of the resin particles (for example, a temperature 10 ° C. to 30 ° C. higher than the glass transition temperature of the resin particles) to fuse the agglomerated particles. -Merge to form toner particles.

Toner particles are obtained through the above steps.
After obtaining the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed, the agglomerated particle dispersion liquid and the resin particle dispersion liquid in which the resin particles are dispersed are further mixed, and the resin particles are further adhered to the surface of the agglomerated particles. The step of forming the second agglomerated particles and the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed are heated, and the second agglomerated particles are fused and united to form a core. -Toner particles may be produced through a step of forming toner particles having a shell structure.

After the fusion / coalescence step is completed, the toner particles formed in the solution are subjected to a known washing step, solid-liquid separation step, and drying step to obtain a dried toner particle. In the cleaning step, from the viewpoint of chargeability, it is preferable to sufficiently perform replacement cleaning with ion-exchanged water. In the solid-liquid separation step, suction filtration, pressure filtration and the like may be performed from the viewpoint of productivity. From the viewpoint of productivity, the drying step may be freeze-dried, air-flow-dried, fluid-dried, vibrating fluid-dried or the like.

Then, the toner according to the present embodiment is produced, for example, by adding an external additive to the obtained dry toner particles and mixing them. The mixing may be carried out by, for example, a V blender, a Henschel mixer, a Ladyge mixer or the like. Further, if necessary, coarse particles of toner may be removed by using a vibration sieving machine, a wind sieving machine, or the like.

<Static charge image developer>
The replenishing toner contained in the replenishing toner container of the image forming apparatus according to the present embodiment is replenished to the developing means and used as an electrostatic charge image developing agent for image forming. The electrostatic charge image developer contains at least a replenishing toner. The electrostatic charge image developer may be a one-component developer containing only a replenishing toner, or a two-component developer in which the toner and a carrier are mixed.

The carrier is not particularly limited, and examples thereof include known carriers. As the carrier, for example, a coating carrier in which the surface of a core material made of magnetic powder is coated with a resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed in a matrix resin; and a porous magnetic powder is impregnated with resin. Examples thereof include a resin-impregnated carrier. The magnetic powder dispersion type carrier and the resin impregnation type carrier may be carriers in which the constituent particles of the carrier are used as a core material and the surface thereof is coated with a resin.

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

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, and styrene-acrylic acid. Examples thereof include an ester copolymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polypropylene, a phenol resin, an epoxy resin and the like. The coating resin and the matrix resin may contain other additives such as conductive particles. Examples of the conductive particles include metals such as gold, silver and copper, and particles such as carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate and potassium titanate.

In order to coat the surface of the core material with a resin, a method of coating with a coating resin and a coating layer forming solution in which various additives (used if necessary) are dissolved in an appropriate solvent can be mentioned. The solvent is not particularly limited, and may be selected in consideration of the type of 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 a coating layer forming solution; a spray method in which the coating layer forming solution is sprayed onto the core material surface; and the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a solution for forming a coating layer is sprayed; a kneader coater method in which a core material of a carrier and a solution for forming a coating layer are mixed in a kneader coater, and then the solvent is removed.

The mixing ratio (mass ratio) of the toner and the carrier in the two-component developer is preferably toner: carrier = 1: 100 to 30: 100, and more preferably 3: 100 to 20: 100.

Hereinafter, embodiments of the invention will be described in detail with reference to Examples, but the embodiments of the invention are not limited to these Examples. In the following description, unless otherwise specified, "parts" and "%" are based on mass.

<Preparation of first silica particles>
[Preparation of silica particle dispersion (1)]
To a glass reaction vessel equipped with a stirrer, a dropping nozzle and a thermometer, 300 parts of methanol and 70 parts of 10% aqueous ammonia were added and mixed to obtain an alkaline catalyst solution. After adjusting this alkaline catalyst solution to 30 ° C., 185 parts of tetramethoxysilane and 50 parts of 8% aqueous ammonia are added dropwise at the same time with stirring to obtain a hydrophilic silica particle dispersion (solid content 12%). It was. Here, the dropping time was set to 30 minutes. Then, the obtained silica particle dispersion was concentrated to a solid content of 40% with a rotary filter R-fine (manufactured by Kotobuki Kogyo Co., Ltd.). This concentrated product was used as a silica particle dispersion liquid (1).

[Preparation of silica particle dispersions (2) to (8) and (c1) to (c6)]
In the preparation of the silica particle dispersion liquid (1), according to Table 1, the amount of ammonia water in the alkaline catalyst solution, the total amount of tetramethoxysilane added under the conditions for forming silica particles, the total amount of ammonia water added dropwise, the dropping time and the start of dropping. Silane particle dispersions (2) to (8) and (c1) to (c6) were prepared in the same manner as the silica particle dispersion (1) except that the temperature was changed.

[Preparation of silica particles (S1)]
Using the silica particle dispersion liquid (1), the silica particles were surface-treated with a siloxane compound in a supercritical carbon dioxide atmosphere as shown below. For the surface treatment, an apparatus equipped with a carbon dioxide cylinder, a carbon dioxide pump, an entrainer pump, an autoclave with a stirrer (capacity 500 ml), and a pressure valve was used.

First, 300 parts of the silica particle dispersion liquid (1) was put into an autoclave with a stirrer (capacity: 500 ml), and the stirrer was rotated at 100 rpm. Then, liquefied carbon dioxide was injected into the autoclave, and the pressure was increased by a carbon dioxide pump while raising the temperature with a heater to bring the inside of the autoclave into a supercritical state at 150 ° C. and 15 MPa. Supercritical carbon dioxide is circulated from the carbon dioxide pump while keeping the inside of the autoclave at 15 MPa with a pressure valve, methanol and water are removed from the silica particle dispersion (1) (solvent removal step), and silica particles (untreated silica particles). ) Was obtained.

Next, when the distribution amount of supercritical carbon dioxide (integrated amount: measured as the distribution amount of carbon dioxide in the standard state) reached 900 copies, the distribution of supercritical carbon dioxide was stopped.
After that, the temperature was maintained at 150 ° C. by the heater and the pressure was maintained at 15 MPa by the carbon dioxide pump, and the supercritical state of carbon dioxide was maintained in the autoclave. Hexamethyldisilazane (HMDS: manufactured by Organic Synthetic Chemicals Industry Co., Ltd.) as a hydrophobic treatment agent in advance, and dimethyl silicone oil (DSO: trade name "KF-96 (manufactured by Shinetsu Chemical Industry Co., Ltd.)" as a siloxane compound having a viscosity of 10000 cSt. ) ”) After injecting a treatment agent solution in which 0.3 part was dissolved into an autoclave with an entrainer pump, the reaction was carried out at 180 ° C. for 20 minutes with stirring. Then, supercritical carbon dioxide was circulated again to remove the excess treatment agent solution. After that, stirring was stopped, the pressure valve was opened, the pressure in the autoclave was released to atmospheric pressure, and the temperature was lowered to room temperature (25 ° C.).
As described above, the solvent removing step and the surface treatment with HMDS and DSO were sequentially performed to obtain silica particles (S1) surface-treated with the hydrophobizing agent.

[Preparation of silica particles (S2) to (S8) and (cS1) to (cS6)]
Silica particles (S2) to (S8) and (cS1) to (cS6) surface-treated with a hydrophobizing agent were obtained in the same manner as in the preparation of the silica particles (S1).

[Preparation of silica particles (cS7) to (cS8)]
Hydrophobic silica particles (cS7) were obtained in the same manner as in paragraphs 0051 to 0053 of JP-A-2008-174430. Further, hydrophobic silica particles (cS8) were obtained in the same manner as in paragraph 0019 of JP-A-2001-194824.

<Preparation of particle dispersion>
[Preparation of amorphous polyester resin particle dispersion (A1)]
・ Terephthalic acid: 70 parts ・ Fumaric acid: 30 parts ・ Ethylene glycol: 45 parts ・ 1,5-pentanediol: 46 parts In a flask equipped with a stirrer, nitrogen introduction tube, temperature sensor, and rectification tower, the above The material was charged and the temperature was raised to 220 ° C. in 1 hour under a nitrogen gas stream, and 1 part of titanium tetraethoxydo was added to a total of 100 parts of the above material. The temperature was raised to 240 ° C. over 0.5 hours while distilling off the generated water, and the dehydration condensation reaction was continued at that temperature for 1 hour, and then the reaction product was cooled. In this way, a polyester resin having a weight average molecular weight of 9500 and a glass transition temperature of 62 ° C. was synthesized.

40 parts of ethyl acetate and 25 parts of 2-butanol were added to a container equipped with a temperature control means and a nitrogen substitution means to prepare a mixed solvent, and then 100 parts of a polyester resin was gradually added to dissolve the mixture. An aqueous ammonia solution (equivalent to 3 times the molar ratio of the acid value of the resin) was added and stirred for 30 minutes. Next, the inside of the container was replaced with dry nitrogen, the temperature was maintained at 40 ° C., and 400 parts of ion-exchanged water was added dropwise at a rate of 2 parts / minute while stirring the mixed solution to emulsify. After completion of the dropping, the emulsion was returned to 25 ° C. to obtain a resin particle dispersion liquid in which resin particles having a volume average particle size of 200 nm were dispersed. Ion-exchanged water was added to the resin particle dispersion to adjust the solid content to 20% to obtain an amorphous polyester resin particle dispersion (A1).

[Preparation of crystalline polyester resin particle dispersion (C1)]
・ 1,10-decandicarboxylic acid: 98 parts ・ Dimethyl-5-sulfonate sodium isophthalate: 24 parts ・ 1,9-nonanediol: 100 parts ・ Dibutyltin oxide (catalyst): 0.3 parts Heat-dried three-necked After the above components were placed in the flask, the air in the flask was brought into an inert atmosphere with nitrogen gas by a reduced pressure operation, and the flask was stirred and refluxed at 180 ° C. for 5 hours by mechanical stirring. Then, the temperature was gradually raised to 230 ° C. under reduced pressure, and the mixture was stirred for 2 hours. When it became viscous, it was air-cooled to stop the reaction to obtain a crystalline polyester resin. By molecular weight measurement (in terms of polystyrene), the weight average molecular weight (Mw) of the crystalline polyester resin was 9700, and the melting temperature was 78 ° C.

Using 90 parts of the obtained crystalline polyester resin, 1.8 parts of the anionic surfactant Neogen RK (Daiichi Kogyo Seiyaku), and 210 parts of ion-exchanged water, heat to 100 ° C., and use IKA Ultratarax. After dispersion at T50, dispersion treatment was carried out with a pressure discharge type Gorin homogenizer for 1 hour to obtain a crystalline polyester resin particle dispersion liquid (C1) having a volume average particle size of 200 nm and a solid content of 20%.

[Preparation of styrene acrylic resin particle dispersion (B1)]
-Styrene: 200 parts-n-butyl acrylate: 50 parts-Acrylic acid: 1 part-β-carboxyethyl acrylate: 3 parts-Propanediol diacrylate: 1 part-2-Hydroxyethyl acrylate: 0.5 parts-Dodecanthiol A solution in which 4 parts of an anionic surfactant (Dowfax manufactured by Dow Chemical Co., Ltd.) was dissolved in 550 parts of ion-exchanged water was placed in a 1-part flask, and a mixed solution containing the above raw materials was placed therein and emulsified. While slowly stirring the emulsion for 10 minutes, 50 parts of ion-exchanged water in which 6 parts of ammonium persulfate was dissolved was added. Then, nitrogen substitution in the system was sufficiently carried out, and the system was heated to 75 ° C. in an oil bath and polymerized for 30 minutes.

next,
-Styrene: 110 parts-n-butyl acrylate: 50 parts-β-carboxyethyl acrylate: 5 parts-1,10-decanediol diacrylate: 2.5 parts-Dodecanethiol: 2 parts A mixture of the above raw materials Was emulsified, the emulsion was added to the flask for 120 minutes, and the emulsion polymerization was continued for 4 hours as it was. As a result, a resin particle dispersion liquid in which resin particles having a weight average molecular weight of 32,000, a glass transition temperature of 53 ° C., and a volume average particle size of 240 nm were dispersed was obtained. Ion-exchanged water was added to the resin particle dispersion to adjust the solid content to 20% to obtain a styrene acrylic resin particle dispersion (B1).

[Preparation of mold release agent particle dispersion]
・ Paraffin wax (HNP-9 manufactured by Nippon Seiwa Co., Ltd.): 100 parts ・ Anionic surfactant (Neogen RK manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 1 part ・ Ion exchange water: 350 parts The particles are mixed, heated to 100 ° C., dispersed using a homogenizer (Ultratarax T50 manufactured by IKA), and then dispersed with a Manton Gorin high-pressure homogenizer (manufactured by Gorin) to release agent particles having a volume average particle size of 200 nm. A release agent particle dispersion liquid (solid content 20%) was obtained.

[Preparation of black colored particle dispersion]
-Carbon black (manufactured by Cabot, Regal330): 50 parts-Anionic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.): 5 parts-Ion-exchanged water: 192.9 parts The above ingredients are mixed and the ultimateizer (Sugino Machine) A black-colored particle dispersion (solid content 20%) was prepared by treating with 240 MPa for 10 minutes.

<Preparation of toner particles>
[Preparation of toner particles (A1)]
-Ion-exchanged water: 200 parts-Amorphous polyester resin particle dispersion liquid (A1): 150 parts-Crystalographic polyester resin particle dispersion liquid (C1): 10 parts-Black colored particle dispersion liquid: 15 parts-Release particle Dispersion: 10 parts, anionic surfactant (TaycaPower): 2.8 parts Put the above materials in a round stainless steel flask, add 0.1N nitrate to adjust the pH to 3.5, and then poly. An aqueous PAC solution prepared by dissolving 2.0 parts of aluminum chloride (PAC, manufactured by Oji Paper Co., Ltd .: 30% powder product) in 30 parts of ion-exchanged water was added. After dispersing at 30 ° C. using a homogenizer (Ultra Tarax T50 manufactured by IKA), the mixture was heated to 45 ° C. in a heating oil bath and held until the volume average particle size became 4.8 μm. Then, 60 parts of the amorphous polyester resin particle dispersion (A1) was added and held for 30 minutes. Then, when the volume average particle size became 5.2 μm, 60 parts of the amorphous polyester resin particle dispersion (A1) was further added and held for 30 minutes. Subsequently, 20 parts of a 10% NTA (nitrilotriacetic acid) metal salt aqueous solution (Kirest 70: manufactured by Kirest Co., Ltd.) was added, and then the pH was adjusted to 9.0 using a 1N sodium hydroxide aqueous solution. Then, 1.0 part of an anion activator (TaycaPower) was added and heated to 85 ° C. while continuing stirring, and kept for 5 hours. Then, the mixture was cooled to 20 ° C. at a rate of 20 ° C./min, filtered, thoroughly washed with ion-exchanged water, and dried to obtain toner particles (A1) having a volume average particle size of 6.0 μm.

[Preparation of toner particles (B1)]
・ Ion exchange water: 400 parts ・ Styrene acrylic resin particle dispersion (B1): 200 parts ・ Black colored particle dispersion: 40 parts ・ Release agent particle dispersion: 12 parts The above components are added to a thermometer, pH meter, and stirrer. The particles were placed in a reaction vessel equipped with the above-mentioned particles, and kept at a temperature of 30 ° C. and a stirring rotation speed of 150 rpm for 30 minutes while controlling the temperature from the outside with a mantle heater. Disperse with a homogenizer (manufactured by IKA Japan Co., Ltd .: Ultratarax T50) and dissolve 2.1 parts of polyaluminum chloride (PAC, manufactured by Oji Paper Co., Ltd .: 30% powder product) in 100 parts of ion-exchanged water. PAC aqueous solution was added. Then, the temperature was raised to 50 ° C., the particle size was measured with Coulter Multisizer II (aperture diameter: 50 μm, manufactured by Coulter), and the volume average particle size was set to 5.0 μm. After that, 115 parts of the resin particle dispersion liquid (1) was additionally added to attach the resin particles to the surface of the aggregated particles (shell structure). Subsequently, 20 parts of a 10% NTA (nitrilotriacetic acid) metal salt aqueous solution (Kirest 70: manufactured by Kirest Co., Ltd.) was added, and then the pH was adjusted to 9.0 using a 1N sodium hydroxide aqueous solution. Then, the temperature was raised to 91 ° C. at a heating rate of 0.05 ° C./min and held at 91 ° C. for 3 hours, and then the obtained toner slurry was cooled to 85 ° C. and held for 1 hour. Then, it cooled to 25 degreeC to obtain magenta toner. This was further redispersed with ion-exchanged water, filtered repeatedly, washed until the electrical conductivity of the filtrate became 20 μS / cm or less, and then vacuum dried in an oven at 40 ° C. for 5 hours. Toner particles (B1) were obtained.

<Toner preparation>
[Preparation of toner (A1)]
100 parts of toner particles (A1), 1.5 parts of silica particles (S1), and 0.5 parts of titania particles (manufactured by Teika Co., Ltd.) having a number average particle diameter of 40 nm, which are inorganic oxide particles, are mixed and sampled. The particles were mixed using a mill at a rotation speed of 13000 rpm for 30 seconds. Toner (A1) was obtained by sieving with a vibrating sieve having a mesh size of 45 μm.

[Preparation of toners (A2) to (A12), (B1) to (B12) and (cA1) to (cA8)]
Each toner was obtained in the same manner as the toner (A1) except that the types or amounts of the toner particles, the first silica particles and the inorganic oxide particles were set to the specifications shown in Table 2. In Table 2, "-" indicates that it does not have inorganic oxide particles. The following silica particles or titania particles were used in the toners (A10) to (A12) and (B10) to (B12).
-Silica particles with an average particle size of 40 nm (manufactured by Aerosil Japan)
-Titania particles with an average number of particles of 55 nm-Titania particles with an average number of particles of 7 nm (manufactured by Titan Kogyo)

<Preparation of developer>
[Preparation of developing agents (A1) to (A12), (B1) to (B12) and (cA1) to (cA8)]
10 parts of each toner and 100 parts of the following resin-coated carrier were placed in a V-type blender and stirred for 20 minutes, and then sieved with a vibrating sieve having a mesh size of 212 μm to obtain a developer.
-Mn-Mg-Sr-based ferrite particles (average particle size 40 μm): 100 parts-Toluene: 14 parts-Polymethyl methacrylate: 2 parts-Carbon black (VXC72: manufactured by Cabot): 0.12 parts Excluding ferrite particles The material and glass beads (diameter 1 mm, the same amount as toluene) were mixed and stirred at a rotation speed of 1200 rpm for 30 minutes using a sand mill manufactured by Kansai Paint Co., Ltd. to obtain a dispersion liquid. The dispersion liquid and the ferrite particles were placed in a vacuum degassing type kneader, and the pressure was reduced while stirring to dry the mixture to obtain a resin-coated carrier.

<Performance evaluation>
As an image forming apparatus, a modified machine of an image forming apparatus (model number ApeosPort IV C7780) manufactured by Fuji Xerox Co., Ltd. was prepared. The image forming apparatus includes an air supply port and a rotary positive displacement uniaxial eccentric screw pump in the toner supply path.

[Occurrence of fog in low temperature and low humidity environment]
The toner bottles were filled with the toners of each example and mounted on an image forming apparatus. The developer of each example was put into the developer of the image forming apparatus. The image forming apparatus was temperature-controlled and humidity-controlled in an environment having a temperature of 10 ° C. and a relative humidity of 10% for 24 hours. After controlling the temperature and humidity, images were continuously formed on 1000 sheets of A4 size paper. As for the image, a 20 cm × 25 cm density 100% image was formed on the upper part of the paper in the vertical direction, and Roman letters from A to Z were formed on the lower part in MS Gothic / 14 points / half-width. The state of the 1000th character was visually confirmed and classified as follows.
A: No toner fog is found around the letters.
B: A slight amount of toner fog is observed around the characters (to the extent that it can be confirmed with a magnifying glass 5 times), but this is not a problem.
C: Toner fog is slightly observed around the characters, but it is slight and does not interfere with practical use.
D: Toner fog is visually observed around the characters, but it is slight and acceptable.
E: Toner fogging is observed around the characters, which is not suitable for practical use.

[Reduction of image density in high temperature and high humidity environment]
The toner bottles were filled with the toners of each example and mounted on an image forming apparatus. The developer of each example was put into the developer of the image forming apparatus. The image forming apparatus was temperature-controlled and humidity-controlled in an environment having a temperature of 30 ° C. and a relative humidity of 85% for 24 hours. After controlling the temperature and humidity, images were continuously formed on 2000 sheets of A4 size paper. The image was a halftone image having an area ratio of 90% and an image density of 30%. The 2000th halftone image was visually confirmed and classified as follows.
A: The entire image has sufficient density and there is no uneven density.
B: The concentration is slightly lower than that of A, but there is no unevenness in concentration.
C: There is a part where the concentration is low, but the density unevenness is slight, and there is no problem in practical use.
Compared to D: C, the area of the low-concentration portion is large, and uneven density is observed. It is barely acceptable.
E: The density is low or there is unacceptable density unevenness over the entire image.

1Y, 1M, 1C, 1K photoconductor (example of image holder)
2Y, 2M, 2C, 2K charging roll (an example of charging means)
3 Exposure device (an example of static charge image forming means)
3Y, 3M, 3C, 3K laser beam 4Y, 4M, 4C, 4K developing device (example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (example of primary transfer means)
6Y, 6M, 6C, 6K Photoreceptor cleaning device (an example of cleaning means)
8Y, 8M, 8C, 8K Toner Cartridge 10Y, 10M, 10C, 10K Image Forming Unit 20 Intermediate Transfer Belt (Example of Intermediate Transfer)
22 Drive roll 24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
28 Fixing device (an example of fixing means)
30 Intermediate transfer cleaning device P Recording paper (an example of recording medium)

102 Photoreceptor (Example of image holder)
104 Developing device (an example of developing means)
200 Toner replenishment path 202 Toner container mounting part 204 Air supply port 206 Screw pump 206a Stator 206b Rotor 208 Toner transport pipe 300 Replenishment toner container

Claims (13)

Image holder and
A charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means that accommodates an electrostatic charge image developer and develops an electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
A replenishment toner container for accommodating the replenishment toner to be replenished in the developing means, and a replenishment toner container.
It is provided with an air supply port and a screw pump for connecting the replenishing toner container and the developing means, and a toner replenishing path for replenishing the replenishing toner to the developing means.
The replenishment toner has toner particles and a number average particle diameter of 110 nm or more and 130 nm or less, a large diameter side number particle size distribution index (upper GSDp) of less than 1.080, and an average circularity of 0.94 or more and 0. Containing silica particles having a degree of .98 or less and a circularity of 0.92 or more and a ratio of 80% by number or more.
Image forming device. The image forming apparatus according to claim 1, wherein the silica particles have a large-diameter side number particle size distribution index (upper GSDp) of less than 1.075. The image forming apparatus according to claim 1 or 2, wherein the silica particles have a small-diameter side number particle size distribution index (lower GSDp) of less than 1.080. The image forming apparatus according to any one of claims 1 to 3, wherein the silica particles have an average circularity of 0.95 or more and 0.97 or less. The image forming apparatus according to any one of claims 1 to 4, wherein the ratio of the circularity of the silica particles to 0.92 or more is 85% by number or more. The image forming apparatus according to any one of claims 1 to 5, wherein the replenishing toner further contains inorganic oxide particles having a number average particle diameter of 5 nm or more and 50 nm or less. The image forming apparatus according to claim 6, wherein the content of the inorganic oxide particles contained in the replenishing toner is smaller than the content of the silica particles. The image forming apparatus according to claim 6 or 7, wherein the ratio Da / Db of the number average particle diameter Da of the silica particles to the number average particle diameter Db of the inorganic oxide particles is 2.5 or more and 20 or less. .. The image forming apparatus according to any one of claims 1 to 8, wherein the toner particles contain a styrene acrylic resin as a binder resin. The image forming apparatus according to any one of claims 1 to 9, wherein the toner particles contain an amorphous polyester resin as a binder resin. The image forming apparatus according to any one of claims 1 to 10, wherein the screw pump is a rotary positive displacement uniaxial eccentric screw pump. The screw pump has a stator and a rotor disposed inside the stator.
The image forming apparatus according to any one of claims 1 to 11, wherein the stator is an elastic body. The image forming apparatus according to claim 12, wherein the elastic body is at least one selected from the group consisting of nitrile butadiene rubber, ethylene propylene rubber, silicone rubber, and urethane rubber.

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