JP2015004887A - Image forming apparatus, image forming method, toner for electrostatic latent image development, and recovery toner for electrostatic latent image development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus which secures portability of a supply toner and improves recovery efficiency of a recovery toner in a recovery container.SOLUTION: The image forming apparatus comprises an image holding body, charging means, latent image forming means, developing means, transfer means, cleaning means and toner supply means. As the supply toner, a supply toner is used which contains toner particles whose volume average particle size is 2.0 μm or more and 5.0 μm or less, and silica particles as an external additive. In the supply toner the BET specific surface area is 2.8 m/g or more and 4.2 m/g or less and the isolation rate of the silica particle is 0.64 mass% or more and 2.60 mass% or less. In the recovery toner recovered by cleaning of the cleaning means the BET specific surface area is 1.5 m/g or more and 2.8 m/g or less, the isolation rate of the silica particle is 0.13 mass% or more and 2.00 mass% or less, and the angle of repose is smaller than that of the supply toner.

Description

  The present invention relates to an image forming apparatus, an image forming method, and a collected toner for developing an electrostatic latent image.

The electrophotographic method is widely used for copying machines, printers, and the like.
For example, Patent Document 1 states that “a toner has a volume average particle diameter Dv of 3 to 15 × 10 ⁻⁶ m, a volume distribution variation coefficient CV of 15 to 35%, and a number distribution variation coefficient CP of 20 to 40. And the product of the specific surface area A (m ² / g), the volume average particle diameter Dv (m), and the true specific gravity ρ (g / m ³ ) of the toner is 10 to 40. Is proposed.

  Patent Document 2 states that “silica having a particle size of 25 μm or more and 1.0% or less on the surface of the toner base is 0.4 to 1.0% by weight based on the weight of the toner base. A toner for a toner recycling system having an apparent density C of 0.29 to 0.32 g / ml, wherein the toner base has a silica amount of 50 wt% to less than 100 wt% of the total amount of silica added. The second stage of adhesion treatment is performed with the remaining silica, and the apparent density A (g / ml) of the toner base not treated with silica is compared with the first stage. There has been proposed a “toner for toner recycling system that satisfies the relationship of 0.9 ≦ B / A ≦ 1.0” with the apparent density B (g / ml) of the toner base adhered by silica.

Patent Document 3 states that “a toner used in an electrophotographic image forming apparatus having a recycling mechanism for returning toner collected from a cleaning unit to a developing unit, and using a screw coil as a conveying means for the collected toner, An electrophotographic toner in which the dynamic friction coefficient of the toner is 0.18 to 0.30 has been proposed.
Patent Document 4 states that “a toner used in an electrophotographic image forming apparatus having a recycling mechanism for returning toner collected from a cleaning unit to a developing unit and using a screw coil as a conveying means for the collected toner, An electrophotographic toner having a loose apparent density of 0.3 g / cc or more has been proposed.
Patent Document 5 states that “a toner used in an electrophotographic image forming apparatus having a recycling mechanism for returning toner collected from a cleaning unit to a developing unit and using a screw coil as a conveying means for the collected toner, An “electrophotographic toner” in which the toner has a volume average particle diameter of 5 to 10 μm and 60 to 80% by number of particles of 5 μm or less has been proposed.

  Further, Patent Document 6 discloses an image forming method using a screw coil as a means for transporting collected toner in a recycling system for returning collected toner from cleaning to a developing unit, and using toner having an aggregation degree of 30% or less. An “image forming method” has been proposed.

JP 2000-47432 A JP 2001-281916 A Japanese Patent Laid-Open No. 2002-365827 JP 2002-365830 A JP 2002-365831 A JP 2003-5427 A

  An object of the present invention is to provide an image forming apparatus that secures the replenishment toner transportability and improves the recovery efficiency of the recovered toner.

The above problem is solved by the following means. That is,
The invention according to claim 1
An image carrier,
Charging means for charging the surface of the image carrier;
Latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier;
Silica particles comprising toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive and having a BET specific surface area of 2.8 m ² / g or more and 4.2 m ² / g or less In a developing unit containing a developer having a liberation ratio of 0.64% by mass or more and 2.60% by mass or less and a carrier having a volume average particle diameter of 10 μm or more and 32 μm, Developing means for developing the electrostatic latent image formed on the image carrier to form a toner image;
Transfer means for transferring the toner image formed on the image carrier to a recording medium;
Cleaning means having a cleaning blade for cleaning the toner remaining on the surface of the image carrier;
The developing means includes toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive, and a BET specific surface area of 2.8 m ² / g or more and 4.2 m ² / g or less. Toner replenishing means for replenishing replenishment toner having a liberation rate of the silica particles of 0.64% by mass or more and 2.60% by mass or less;
With
The BET specific surface area of the collected toner collected by cleaning of the cleaning means is 1.5 m ² / g or more and 2.8 m ² / g or less, and the liberation rate of silica particles is 0.13 mass% or more and 2.00 mass% or less. An image forming apparatus having an angle of repose smaller than the angle of repose of the replenishing toner.

The invention according to claim 2
A charging step for charging the surface of the image carrier;
A latent image forming step of forming an electrostatic latent image on the surface of the charged image carrier;
Silica particles comprising toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive and having a BET specific surface area of 2.8 m ² / g or more and 4.2 m ² / g or less The electrostatic image formed on the image carrier by a developer having a toner having a liberation ratio of 0.64% by mass or more and 2.60% by mass or less and a carrier having a volume average particle size of 10 μm or more and 32 μm. A developing step of developing a latent image to form a toner image;
A transfer step of transferring the toner image formed on the image carrier to a recording medium;
A cleaning step of cleaning the toner remaining on the surface of the image carrier with a cleaning blade;
The developing means includes toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive, and a BET specific surface area of 2.8 m ² / g or more and 4.2 m ² / g or less. A toner replenishing step of replenishing a replenishment toner having a silica particle liberation rate of 0.64% by mass or more and 2.60% by mass or less;
With
The BET specific surface area of the collected toner collected by the cleaning in the cleaning step is 1.5 m ² / g or more and 2.8 m ² / g or less, and the liberation rate of the silica particles is 0.13 mass% or more and 2.00 mass% or less. An image forming method in which the angle of repose is smaller than the angle of repose of the replenishing toner.

The invention according to claim 3
Including toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive,
The BET specific surface area is 2.8 m ² / g or more and 4.2 m ² / g or less, the liberation rate of silica particles is 0.64 mass% or more and 2.60 mass% or less, and the angle of repose is 40 ° or less. A toner for developing an electrostatic latent image.

The invention according to claim 4
Including toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive,
The BET specific surface area is 1.5 m ² / g or more and 2.8 m ² / g or less, the release rate of the silica particles is 0.13 mass% or more and 2.00 mass% or less, and the angle of repose is 35 ° or less. Yes,
A collected toner for developing an electrostatic latent image, which is collected by cleaning the toner remaining on the surface of the image carrier after the toner image formed on the image carrier by the toner is transferred to a recording medium.

  According to the first aspect of the present invention, there is provided an image forming apparatus that ensures the replenishment toner transportability and improves the recovery efficiency of the recovered toner as compared with the case where the supply toner, the recovered toner, and the carrier do not satisfy the above characteristics. Is done.

  According to the second aspect of the present invention, there is provided an image forming method that ensures the replenishment toner transportability and improves the recovery efficiency of the recovered toner as compared with the case where the supply toner, the recovered toner, and the carrier do not satisfy the above characteristics. Is done.

  According to the third aspect of the invention, there is provided a toner for developing an electrostatic latent image that ensures transportability and improves the recovery efficiency of the recovered toner, as compared with the case where the above characteristics are not satisfied.

  According to the fourth aspect of the present invention, there is provided a recovered toner for developing an electrostatic latent image that improves the recovery efficiency as compared with a case where the above characteristics are not satisfied.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows the image forming apparatus which concerns on other this embodiment. It is a figure which shows the change of the angle of repose of the toner with respect to mechanical strength.

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

The image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, a latent image forming unit that forms an electrostatic latent image on the surface of the charged image carrier, and development. Developing means for containing the agent and developing the electrostatic latent image formed on the image carrier with the developer to form a toner image, and transfer means for transferring the toner image formed on the image carrier to the recording medium And a cleaning unit having a cleaning blade for cleaning the toner remaining on the surface of the image carrier, and a toner replenishing unit for replenishing the replenishing toner to the developing unit.
The developer includes toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles which are external additives, and has a BET specific surface area of 2.8 m ² / g or more and 4.2 m ² / g or less. And a toner having a silica particle liberation rate of 0.64% by mass or more and 2.60% by mass or less and a carrier having a volume average particle size of 10 μm or more and 32 μm.
On the other hand, the replenishment toner also includes toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive, and has a BET specific surface area of 2.8 m ² / g or more and 4.2 m ² / g. A toner having a silica particle liberation ratio of 0.64% by mass or more and 2.60% by mass or less is applied.
The BET specific surface area of the collected toner collected by cleaning of the cleaning means is 1.5 m ² / g or more and 2.8 m ² / g or less, and the liberation rate of silica particles is 0.13 mass% or more and 2.00 mass% or less. In addition, the angle of repose is smaller than the angle of repose of the replenishing toner.

  In the present specification, the term “toner” simply refers to replenishing toner (that is, toner used for development).

  Here, in recent years, for example, for the purpose of realizing high image quality, toner (toner particles) has been reduced in diameter (in the range of volume average particle diameter of 2.0 μm to 5.0 μm). Thereby, the graininess and density reproducibility of the human skin portion of the photograph, the halftone portion such as the sky cloud, and the gradation portion are improved.

  It is known that the toner fluidity deteriorates when the diameter of the toner (toner particles) is reduced. One of the causes of deterioration of fluidity due to toner (toner particle) diameter reduction is that the surface area per unit weight increases due to diameter reduction, and the contact, friction, and load are larger than those of a large diameter toner. .

  The fluidity of the toner is improved by the fluidity of the toner particles themselves, the type of external additive, the particle size, the amount added, and the adhesion state thereof. That is, even if the fluidity of the toner particles itself deteriorates, the fluidity of the toner is improved by the external additive. Silica particles are suitable as such an external additive.

  By the way, when the change in the angle of repose of the toner with respect to the mechanical load is examined (see the dotted line in FIG. 3), the angle of repose decreases as the mechanical negative load increases, and the fluidity increases. This is presumably because the dispersibility of the silica particles externally added to the toner particles increases due to the mechanical load, and the liberation rate of the silica particles decreases. Further, when the mechanical negative load increases, the lowered angle of repose increases. This is presumably because the increase in mechanical load further reduces the liberation rate of the silica particles and causes the silica particles externally added to the toner particles to be embedded in the toner particles.

For this reason, the recovered toner is deteriorated in fluidity and the angle of repose is increased by a mechanical load due to, for example, development, transfer, and cleaning.
When the angle of repose of the collected toner is high, the collected toner partially creates a mountain in the collecting container that stores the collected toner collected by the cleaning blade, and before the collected toner is filled in the collecting container, A phenomenon occurs in which the detection sensor detects the apex. For this reason, the amount of collected toner that can be actually collected in a collection container having a constant volume is reduced, that is, the collection efficiency is lowered. As a result, not only the recovery efficiency of the recovered toner is reduced, but also the replacement frequency of the recovery container is increasing.

Therefore, in the image forming apparatus according to the present embodiment, the toner (replenishment toner) includes toner particles having a volume average particle diameter of 2.0 μm or more and 5.0 μm or less and silica particles which are external additives, and has a BET specific surface area. By applying a toner having a silica particle liberation rate of 0.64% by mass to 2.60% by mass with a BET specific surface area of the recovered toner of 2.8 m ² / g to 4.2 m ² / g. Is 1.5 m ² / g or more and 2.8 m ² / g or less, the liberation rate of the silica particles is 0.13 mass% or more and 2.00 mass% or less, and the angle of repose is made smaller than the angle of repose of the replenishing toner.

When the change in the angle of repose with respect to the mechanical load of the toner (replenishment toner) having the BET specific surface area and the silica particle liberation ratio in this specific range is examined (see the solid line in FIG. 3), the increase as the mechanical negative load increases. Without doing so, the angle of repose continues to decline and the fluidity increases. As a result, it was found that the angle of repose of the collected toner was lower than the angle of repose of the toner, and the fluidity of the collected toner was increased.
This is because a large amount of silica particles of an appropriate size are adhered to small-diameter toner particles having a volume average particle diameter within the above range, and the BET specific surface area of the toner is increased to be within the above range. This is because the embedding of the silica particles into the toner particles due to the load is considered to be suppressed. In addition, by reducing the adhesion strength of the silica particles to the toner particles and increasing the liberation rate of the silica particles to the above range, the mechanical load until the silica particles are embedded in the toner particles is high. It is because it is thought that it will shift to the side.
That is, a toner having a specific range of BET specific surface area and silica particle liberation rate does not embed silica particles in the toner particles even when a mechanical load is applied by, for example, development, transfer, and cleaning. It is considered that the dispersibility of the silica particles externally added to the toner particles is increased, and the liberation rate of the silica particles is appropriately reduced.

On the other hand, if the angle of repose of the toner is lowered and the fluidity is excessively increased in order to keep the angle of repose of the collected toner low, the toner transportability is deteriorated. When the toner transportability is deteriorated, a rippling phenomenon occurs when the toner is filled in the toner cartridge, or the scraping property is also deteriorated, so that a residual toner remaining in the developing device or in the toner cartridge is increased. Sometimes.
In contrast, the BET specific surface area of the toner (supplement toner) is within the above range to suppress excessive adhesion of the silica particles to the toner particles, and the silica particle adhesion strength to the toner particles is within the above range. It is considered that deterioration of the toner transportability is suppressed by preventing the toner from being excessively weakened.

  In addition, by setting the volume average particle diameter D50v of the carrier to 10 μm or more and 32 μm or less, the mechanical strength of the carrier to the toner is reduced, and the embedding of the silica particles in the toner particles is further suppressed.

As described above, in the image forming apparatus according to the present embodiment, by applying a toner (replenishment toner) having a BET specific surface area in a specific range and a silica particle liberation rate, the BET specific surface area of the recovered toner is 1.5 m ^2. / G or more and 2.8 m ² / g or less, the liberation rate of silica particles is 0.13 mass% or more and 2.00 mass% or less, and the angle of repose becomes smaller than the angle of repose of the toner (supplement toner), and the toner (supplement Toner transportability is ensured, and the collection efficiency of the collected toner in the collection container is improved.

The BET specific surface area of the toner is 2.8 m ² / g or more and 4.2 m ² / g or less, preferably 3 m ² / g or more and 3.8 m ² / g or less, more preferably 3 m ² / g or more and 3.5 m or less. ² / g or less. By setting the BET specific surface area of the toner to 2.8 m ² / g or more, the BET specific surface area of the recovered toner falls within the above range under the mechanical load applied by development, transfer, cleaning, etc. The angle is smaller than the angle of repose of the toner (supplement toner). On the other hand, by setting the BET specific surface area of the toner to 4.2 m ² / g or less, deterioration of toner (supplement toner) transportability is suppressed.
The BET specific surface area of the toner can be adjusted within the above range by, for example, the particle size of silica particles, the external addition amount (or coverage), and the external addition conditions of silica particles.

The liberation rate of the silica particles of the toner is 0.64% by mass or more and 2.60% by mass or less, preferably 0.7% by mass or more and 2.5% by mass or less, more preferably 0.7% by mass or more and 2.% by mass or less. 3% by mass or less. By setting the liberation rate of the silica particles to 0.64% by mass or more, the range of the liberation rate of the silica particles in the collected toner is within the above range, and the angle of repose of the collected toner is smaller than the angle of repose of the toner (for replenishment). Become. On the other hand, by setting the liberation rate of the silica particles to 2.60% by mass or less, deterioration of the transportability of the toner (replenishment toner) is suppressed.
The liberation rate of the silica particles of the toner can be adjusted within the above range by, for example, the particle size of the silica particles, the external addition amount (or coverage), and the external addition conditions of the silica particles.

  The angle of repose of the toner is higher than the angle of repose of the collected toner. For example, the angle of repose is preferably 15 ° to 40 °, preferably 18 ° to 37 °, and more preferably 20 ° to 35 °. When the repose angle of the toner is 38 ° or more, the repose angle of the collected toner tends to be lower than the repose angle of the toner. On the other hand, when the angle of repose of the toner is in the above range, deterioration of toner transportability due to excessive deterioration of toner fluidity is suppressed.

On the other hand, the BET specific surface area of the collected toner is 1.5 m ² / g or more and 2.8 m ² / g or less, preferably 1.5 m ² / g or more and 2.5 m ² / g or less, and more preferably 1.7 m. ² / g or more and 2.4 m ² / g or less. When the BET specific surface area of the collected toner is within the above range, the collection efficiency of the collected toner in the collection container is improved.

  The liberation rate of the silica particles of the collected toner is 0.13% by mass or more and 2.00% by mass or less. When the liberation rate of the silica particles in the collected toner is within the above range, the collection efficiency of the collected toner in the collection container is improved.

Here, the method for measuring the BET specific surface area of the toner (and the recovered toner) is as follows. In the description of the measurement method, the toner including the collected toner is referred to as toner.
The BET specific surface area is measured by a nitrogen substitution method. Specifically, it was measured by a three-point method using an SA3100 specific surface area measuring device (manufactured by Beckman Coulter, Inc.).

The method for measuring the liberation rate of the silica particles of the toner (and recovered toner) is as follows. In the description of the measurement method, the toner including the collected toner is referred to as toner.
First, 100 ml of ion exchange water and 5.5 ml of 10 mass% Triton X100 aqueous solution (manufactured by Acros Organics) are added to a 200 ml glass bottle, 5 g of toner is added to the mixture, and the mixture is stirred 30 times and allowed to stand for 1 hour or more. Put.
Then, after stirring the mixed solution 20 times, using an ultrasonic homogenizer (manufactured by SONICS & MATERIALS Co., Ltd., product name homogenizer, model VCX750, CV33), a dial was set at an output of 30%, and ultrasonic energy was applied under the following conditions. Apply for 1 minute.
・ Vibration time: 60 seconds continuous ・ Amplitude: 20W (30%) set ・ Vibration start temperature: 23 ± 1.5 ℃
・ Distance between the ultrasonic transducer and the bottom of the container: 10 mm

  Next, the mixed liquid to which ultrasonic energy is applied is suction filtered using a filter paper (trade name: qualitative filter paper (No. 2, 110 mm), manufactured by Advantech Toyo Co., Ltd.), washed twice with ion exchange water again, The free silica particles are removed by filtration, and then the toner is dried.

The amount of silica particles remaining in the toner after removal of the silica particles by the above treatment (hereinafter referred to as the amount of silica particles after dispersion), and the amount of silica particles of the toner that has not been subjected to the treatment for removing the silica particles (hereinafter referred to as the following) The amount of silica particles before dispersion and the amount of silica particles after dispersion are substituted into the following formula.
The value calculated by the following formula is defined as the silica particle liberation rate.
Formula: Silica particle release rate (%) = [(silica particle amount before dispersion−silica particle amount after dispersion) / silica particle amount before dispersion] × 100

The method for measuring the angle of repose of the toner (and recovered toner) is as follows. In the description of the measurement method, the toner including the collected toner is referred to as toner.
Using a powder measuring instrument (made by Hosokawa Micron Corporation, trade name “Powder Tester PTX”), a sample funnel is placed on the stand of this measuring instrument, and a standard sieve with an opening mesh of 60 mesh is further stacked and fixed. The toner for electrostatic charge image development was dropped through a sample funnel onto a circular table having a diameter of 8 cm to form a toner peak, and then the angle between the ridge line of the peak and the horizontal line was measured with a laser beam. Note that the vibration width was adjusted so that the crest of the electrostatic image developing toner did not collapse, and the falling speed of the electrostatic image developing toner was adjusted.

  Hereinafter, the image forming apparatus of the present embodiment will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to the present embodiment.
As shown in FIG. 1, the image forming apparatus 101 according to the present embodiment includes an electrophotographic photosensitive member 10 (an example of an image holding member) that rotates clockwise as indicated by an arrow a, and an electrophotographic photosensitive member. A charging device 20 (an example of a charging unit) that is provided above the body 10 and is opposed to the electrophotographic photoreceptor 10 and charges the surface of the electrophotographic photoreceptor 10, and the electrophotographic photoreceptor 10 charged by the charging device 20. An exposure device 30 (an example of a latent image forming unit) that exposes the surface of the toner to form an electrostatic latent image, and a toner contained in the developer is attached to the electrostatic latent image formed by the exposure device 30. A developing device 40 (an example of a developing unit) that forms a toner image on the surface of the electrophotographic photosensitive member 10, travels in the direction indicated by the arrow b while being in contact with the electrophotographic photosensitive member 10, and the surface of the electrophotographic photosensitive member 10 The toner image formed on the Comprises an intermediate transfer member 50 belt-like that, and a cleaning device 70 for cleaning the surface of the electrophotographic photosensitive member 10 (an example of a cleaning unit).
Here, a replenishment toner container 47 (an example of a toner replenishing unit) for replenishing replenishment toner to the developing device 40 is connected to the developing device 40 via a replenishment conveyance path 46.

  The charging device 20, the exposure device 30, the developing device 40, the intermediate transfer member 50, and the cleaning device 70 are arranged in a clockwise direction on the circumference surrounding the electrophotographic photosensitive member 10.

The intermediate transfer member 50 is held from the inside while being tensioned by the support rollers 50A and 50B, the back roller 50C, and the drive roller 50D, and is driven in the direction of the arrow b as the drive roller 50D rotates. At a position facing the electrophotographic photosensitive member 10 inside the intermediate transfer member 50, the intermediate transfer member 50 is charged to a polarity different from the charging polarity of the toner, and the electrophotographic photosensitive member 10 is placed on the outer surface of the intermediate transfer member 50. A primary transfer device 51 for adsorbing the upper toner is provided. On the outer side below the intermediate transfer member 50, the recording paper P (an example of a recording medium) is charged to a polarity different from the charged polarity of the toner, and the toner image formed on the intermediate transfer member 50 is placed on the recording paper P. A secondary transfer device 52 for transferring is provided to face the back roller 50C.
These members for transferring the toner image formed on the electrophotographic photosensitive member 10 to the recording paper P correspond to an example of a transfer unit.

  Below the intermediate transfer member 50, a recording paper supply device 53 that supplies the recording paper P to the secondary transfer device 52 and a recording paper P on which the toner image is formed in the secondary transfer device 52 are conveyed. A fixing device 80 for fixing the toner image is provided.

  The recording paper supply device 53 includes a pair of transport rollers 53A and a guide plate 53B that guides the recording paper P transported by the transport rollers 53A toward the secondary transfer device 52. On the other hand, the fixing device 80 includes a fixing roller 81 that is a pair of heat rollers for fixing the toner image by heating and pressing the recording paper P onto which the toner image has been transferred by the secondary transfer device 52, and a fixing roller. And a transport belt 82 for transporting the recording paper P toward 81.

  The recording paper P is conveyed in the direction indicated by the arrow c by the recording paper supply device 53, the secondary transfer device 52, and the fixing device 80.

  The intermediate transfer member 50 is further provided with an intermediate transfer member cleaning device 54 having a cleaning blade for removing the toner remaining on the intermediate transfer member 50 after the toner image is transferred to the recording paper P in the secondary transfer device 52. Yes.

  Details of main components in the image forming apparatus 101 according to the present embodiment will be described below.

-Developer-
The developer is a two-component developer containing toner and carrier.
In the developer, the mixing ratio (mass ratio) of the toner and the carrier is, for example, in the range of toner: carrier = 1: 100 to 30: 100.

First, the toner will be described.
The toner includes, for example, toner particles containing a binder resin and a colorant, and external additives that are silica particles. The toner particles may be configured to include other additives such as a release agent as required.
The replenishment toner has the same configuration as the toner in the developer.

The toner particles will be described.
The binder resin is not particularly limited, but styrenes (eg, styrene, chlorostyrene, etc.), monoolefins (eg, ethylene, propylene, butylene, isoprene, etc.), vinyl esters (eg, vinyl acetate, vinyl propionate, Vinyl benzoate, vinyl butyrate, etc.), α-methylene aliphatic monocarboxylic acid esters (eg methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, methacrylic acid) Ethyl acetate, butyl methacrylate, dodecyl methacrylate, etc.), vinyl ethers (eg, vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether), vinyl ketones (eg, vinyl methyl ketone, vinyl hexyl ketone, vinyl isopro) Homopolymers and copolymers of Niruketon etc.), etc., and polyester resins by copolymerization of dicarboxylic acids and diols.

Particularly representative binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer. Examples thereof include a polymer, a polyethylene resin, a polypropylene resin, and a polyester resin.
Typical binder resins include polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like.

  Examples of the colorant include magnetic powder (eg, magnetite, ferrite, etc.), carbon black, aniline blue, caryl blue, chrome yellow, ultramarine blue, dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxa Rate, lamp black, rose bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 is a typical example.

Examples of other additives include mold release agents, magnetic substances, charge control agents, inorganic powders, and the like.
Examples of mold release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester types such as fatty acid esters and montanic acid esters. Wax; and the like, but is not limited thereto.

The characteristics of the toner particles will be described.
The shape of the toner particles may be spherical or irregular, but may be irregular. When the shape of the toner particles is different, it is difficult to apply a mechanical load to the recesses on the surface of the toner particles. Therefore, even if a mechanical load is applied, the liberated amount of the silica particles is easily maintained. For this reason, the shape of the toner particles is preferably different from the viewpoint of ensuring the transportability of the toner (replenishment toner) and improving the recovery efficiency of the recovered toner.

Specifically, the circularity of the toner particles is preferably 0.930 or more and 0.995 or less, desirably 0.940 or more and 0.980 or less, and more desirably 0.950 or more and 0.975 or less.
The degree of circularity of the toner particles is determined by observing the toner particles using a scanning electron microscope (for example, manufactured by Hitachi, Ltd .: S-4100, etc.) and taking an image. For each of the 100 toner particles taken in, the calculation is made based on the following formula, and the average value is obtained. In the electron microscope, the magnification was adjusted so that about 3 to 20 toner particles could be seen in one field of view, and SF2 was calculated based on the following equation together with observation of multiple fields of view.
Formula: Circularity (100 / SF2) = 4π × (A / I ² )
In the formula, I represents the peripheral length of the toner particles on the image, and A represents the projected area of the toner particles. SF2 represents a shape factor. π represents a circumference ratio.

  The toner particles have a volume average particle diameter D50v of 2.0 μm or more and 5.0 μm or less, but preferably 2.5 μm or more and 4.5 μm or less. When the volume average particle diameter D50v of the toner particles is 2.0 μm or more, an increase in the adhesion force between the toner particles due to an excessive increase in the specific surface area is suppressed, and the toner transportability is easily secured. On the other hand, when the volume average particle diameter D50v of the toner particles is 5.0 μm or less, embedding of the silica particles due to a mechanical load is easily suppressed.

Here, the measuring method of the volume average particle diameter D50v of the toner particles is as follows.
First, 0.5 mg to 50 mg of a measurement sample was added to 2 ml of a 5 mass% aqueous solution of a surfactant (desirably sodium alkylbenzenesulfonate) as a dispersant, and this was added to 100 ml to 150 ml of an electrolytic solution. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and a particle size is measured with a Coulter Multisizer II type (manufactured by Beckman-Coulter) using an aperture having an aperture diameter of 100 μm. Is a particle size distribution of particles in the range of 2.0 μm or more and 60 μm or less. The number of particles to be measured is 50,000.
For the particle size range (channel) obtained by dividing the obtained particle size distribution, the volume cumulative distribution is subtracted from the small particle size side, and the particle size that becomes 50% cumulative is defined as the volume average particle size D50v.

The external additive will be described.
Silica particles are employed as the external additive.
Examples of the silica particles include well-known silica particles such as fumed silica particles, sol-gel silica particles, and colloidal silica particles. Among these, sol-gel silica particles are dispersible, charged from the viewpoint of toner fluidity and chargeability. It is desirable because of its excellent controllability.

  The shape of the silica particles may be spherical or irregular, but may be irregular. When the shape of the silica particles is different, the embedding of the silica particles into the toner particles is easily suppressed even when a mechanical load is applied. For this reason, the shape of the silica particles is preferably different from the viewpoint of ensuring the transportability of the toner (replenishment toner) and improving the recovery efficiency of the recovered toner.

Specifically, the circularity of the silica particles is preferably 0.600 or more and 0.930 or less, desirably 0.6500 or more and 0.920 or less, and more desirably 0.700 or more and 0.900 or less.
The circularity of the silica particles is determined by observing the silica particles after being externally added to the toner particles using a scanning electron microscope (for example, manufactured by Hitachi, Ltd .: S-4100) and taking an image, and analyzing the image. For each of the 100 silica particles taken into an apparatus (for example, LUZEX III, manufactured by Nireco), the average value is calculated based on the following formula. In the electron microscope, the magnification was adjusted so that about 3 or more and 20 or less silica particles were captured in one field of view, and SF2 was calculated based on the following equation together with observation of a plurality of fields of view.
Formula: Circularity (100 / SF2) = 4π × (A / I ² )
In the formula, I represents the perimeter of the silica particles on the image, and A represents the projected area of the silica particles. SF2 represents a shape factor. π represents a circumference ratio.

  The volume average particle diameter of the silica particles is, for example, 40 nm or more and 200 nm or less, preferably 40 nm or more and 180 nm or less, and more preferably 50 nm or more and 160 nm or less. When the volume average particle diameter of the silica particles is 20 nm or more, embedding of the silica particles due to a mechanical load is easily suppressed. On the other hand, when the volume average particle diameter of the silica particles is 200 nm or less, an excessive amount of the silica particles is suppressed. For this reason, the volume average particle diameter of the silica particles is preferably within the above range from the viewpoint of ensuring the transportability of the toner (replenishment toner) and improving the recovery efficiency of the recovered toner.

  The volume average particle diameter of the silica particles is determined by observing 100 primary particles of the silica particles after externally adding the silica particles to the toner particles using a scanning electron microscope (SEM) apparatus, and analyzing the silica particles by image analysis. The long diameter and the shortest diameter are measured, and the equivalent sphere diameter is measured from the intermediate value. The 50% diameter (D50v) in the cumulative frequency of the obtained equivalent sphere diameter is defined as the average particle diameter (that is, volume average particle diameter) of the silica particles.

  The surface of the silica particles is preferably subjected to a hydrophobic treatment. The hydrophobic treatment is performed, for example, by immersing inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, aluminum coupling agents and the like. These may be used individually by 1 type and may use 2 or more types together.

  The external addition amount (content) of the silica particles is, for example, from 2.0% by mass to 6.0% by mass with respect to the toner particles, and preferably from 3.0% by mass to 5.5% by mass. More desirably, it is 3.0 mass% or more and 5.0 mass% or less. When the external addition amount (content) of the silica particles is 2.0% by mass or more, the coverage of the silica particles with respect to the toner particles increases, and the embedding of the silica particles due to a mechanical load is easily suppressed. On the other hand, when the external addition amount (content) of the silica particles is 6.0% by mass or less, the excessive release amount of the silica particles can be suppressed. For this reason, from the viewpoint of ensuring the transportability of the toner (replenishment toner) and improving the recovery efficiency of the recovered toner, the external addition amount (content) of the silica particles is preferably within the above range.

  The coverage of the silica particles to the toner particles (hereinafter referred to as silica particle coverage) is, for example, 20% to 120%, desirably 30% to 80%, and more desirably 40% to 80%. When the silica particle coverage is 20% or more, excessive deterioration of the toner fluidity is suppressed, and the toner transportability is easily secured. On the other hand, when the coverage of the toner particles is 120% or less, an excessive amount of silica particles is suppressed. For this reason, the coverage of the silica particles is preferably within the above range from the viewpoint of ensuring the transportability of the toner (replenishment toner) and improving the recovery efficiency of the recovered toner.

In addition, the coverage of a silica particle is the value measured as follows.
Using a FE-SEM (Ultra High Resolution Field Emission Scanning Electron Microscope SU8040 (manufactured by Hitachi High-Technologies Corporation)), 10 images of each toner surface image were taken 10 times, and image analysis software (Win roof) The toner particle surface and the silica particles were color-coded by binarization (by Mitani Corporation), and the area ratio was calculated.

  As the external additive, in addition to the silica particles, other external additives may be used in combination. However, in this case, the external addition amount (content) of the silica particles is preferably 60% by mass or more (desirably 70% by mass) with respect to the entire external additive.

Examples of other external additives include inorganic particles other than silica particles. Examples of the inorganic particles include 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 , etc. Is mentioned.
The surface of the other external additive is preferably subjected to a hydrophobic treatment.

A method for producing toner will be described.
First, the toner particles are not particularly limited by the production method. For example, the toner particles are kneaded and pulverized by adding, for example, a binder resin, a colorant and a release agent, and a charge control agent as necessary. Method: Method of changing the shape of particles obtained by kneading and pulverization method by mechanical impact force or thermal energy; Emulsion polymerization of polymerizable monomer of binder resin, and formed dispersion and colorant And a release agent and, if necessary, a dispersion of a charge control agent or the like, and agglomeration, heat fusion to obtain toner particles; an emulsion polymerization aggregation method; a polymerizable monomer for obtaining a binder resin; A suspension polymerization method in which a solution of a colorant and a release agent, if necessary, a charge control agent is suspended in an aqueous solvent for polymerization; a binder resin, a colorant and a release agent, and optionally charged A solution manufactured by a suspension method, etc., in which a solution of a control agent is suspended in an aqueous solvent and granulated. Over particles are used.

  Further, a known method such as a production method in which the toner particles obtained by the above method are used as a core, and agglomerated particles are further adhered and heated and fused to give a core-shell structure is used. The toner production method is preferably a suspension polymerization method, an emulsion polymerization aggregation method, or a dissolution suspension method in which an aqueous solvent is used from the viewpoint of shape control and particle size distribution control, and an emulsion polymerization aggregation method is particularly desirable.

  The toner is produced by mixing the toner particles and the external additive with a Henschel mixer or a V blender. Further, when the toner particles are produced by a wet method, they may be externally added by a wet method.

Next, the carrier will be described.
Examples of the carrier include a coated carrier in which the surface of a core material made of magnetic powder is coated with a coating resin, a magnetic powder dispersion type carrier in which magnetic powder is dispersed and blended in a matrix resin, and porous magnetic powder impregnated with resin. Resin impregnated type carriers and the like.
The magnetic powder-dispersed carrier and resin-impregnated carrier use as a core a particle in which a magnetic powder is dispersed and blended in a matrix resin, or a particle in which a porous magnetic powder is impregnated with a resin. It may be a carrier coated with.

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

Examples of the coating resin for coating the core material and the matrix resin for dispersing and blending the magnetic powder include, for example, polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, and vinyl chloride. Examples thereof include a vinyl acetate copolymer, a styrene-acrylic acid copolymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenol resin, and an epoxy resin.
In addition, you may include other additives, such as a conductive material, in the coating resin which coat | covers a core material, and resin which disperse | distributes and mix | blends magnetic powder.

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

  The volume average particle diameter D50v of the carrier is, for example, from 10 μm to 32 μm, desirably from 15 to 32 μm, and more desirably from 20 μm to 30 μm. When the volume average particle diameter D50v of the carrier is within the above range, the mechanical strength of the carrier to the toner is reduced, and embedding of the silica particles into the toner particles is easily suppressed. Therefore, from the viewpoint of improving the recovery efficiency of the recovered toner, the volume average particle diameter D50v of the carrier is preferably set in the above range.

  In the volume average particle size distribution index GSDv of the carrier, for example, carrier particles having a particle size of 45 μm or more may be 10% or less (desirably 8% or less, more desirably 5% or less) in the entire carrier. When the ratio of carrier particles having a particle diameter of 45 μm or more is within the above range, embedding of silica particles into toner particles is easily suppressed. For this reason, from the viewpoint of improving the recovery efficiency of the recovered toner, the ratio of carrier particles having a particle diameter of 45 μm or more is preferably set in the above range.

The volume average particle diameter D50v and the volume average particle size distribution index GSDv of the carrier are obtained by measuring with an aperture diameter of 100 μm using a laser scattering particle size measuring device (manufactured by Nikkiso Co., Ltd., Microtrack). At this time, the measurement was performed after the carrier was dispersed in an electrolyte aqueous solution (isoton aqueous solution) and dispersed by ultrasonic waves for 30 seconds or more.
For each particle size range (channel) divided based on the particle size distribution of the carrier measured with a laser scattering particle size measuring device (Nikkiso Co., Ltd., Microtrack), draw the cumulative distribution from the small diameter side, respectively. The volume average particle diameter D50v was set as the particle diameter at 50% cumulative, and the ratio of particles having a particle diameter of 45 μm from the channel was determined in the volume average particle size distribution index GSDv.

-Electrophotographic photoreceptor-
Examples of the electrophotographic photoreceptor 10 include organic photoreceptors and inorganic photoreceptors.
Specifically, the electrophotographic photoreceptor 10 has, for example, 1) a structure in which an undercoat layer is provided on a conductive substrate, and a charge generation layer, a charge transport layer, and a protective layer are sequentially formed thereon. 2) A structure in which an undercoat layer is provided on a conductive substrate and a charge transport layer, a charge generation layer, and a protective layer are sequentially formed thereon, and 3) an undercoat layer is formed on the conductive substrate. And a known layer such as a layer having a structure in which a single-layer type photosensitive layer and a protective layer are sequentially formed thereon.
The charge generation layer and the charge transport layer are function-separated photosensitive layers. In the electrophotographic photoreceptor 10, the undercoat layer may be provided or may not be provided.

-Charging device-
Examples of the charging device 20 include a contact charger using a conductive charging roller, a charging brush, a charging film, a charging rubber blade, a charging tube, and the like. Further, examples of the charging device 20 include a non-contact type roller charger and a known charger such as a scorotron charger using a corona discharge or a corotron charger. As the charging device 20, a contact charger is preferable.
In this embodiment, even if a charger that applies a voltage in which an alternating current is superimposed on a direct current is used or a discharge product is likely to be generated, an electrophotography can be obtained even if such a method is adopted. Adhesion / deposition of discharge products on the photoreceptor 10 is suppressed, and white spots in the image are suppressed.

-Exposure device-
Examples of the exposure apparatus 30 include optical system devices that expose the surface of the electrophotographic photoreceptor 10 with light such as semiconductor laser light, LED light, and liquid crystal shutter light imagewise. The wavelength of the light source is preferably within the spectral sensitivity region of the electrophotographic photoreceptor 10. As the wavelength of the semiconductor laser, for example, near infrared having an oscillation wavelength around 780 nm is preferable. However, the present invention is not limited to this wavelength, and a laser having an oscillation wavelength of 600 nm or a laser having an oscillation wavelength of 400 nm to 450 nm as a blue laser may be used. Further, as the exposure apparatus 30, for example, a surface emitting laser light source of a multi-beam output type is also effective for color image formation.

-Developer-
The developing device 40 is disposed, for example, opposite to the electrophotographic photosensitive member 10 in the developing region, and includes, for example, a developing container 41 that stores a developer (two-component developer) containing toner and a carrier. . The developing container 41 includes a developing container main body 41A and a developing container cover 41B that closes the upper end thereof.

  The developing container main body 41A has, for example, a developing roll chamber 42A that accommodates a developing roll (an example of a developer holding body) 42 on the inner side thereof, and is adjacent to the developing roll chamber 42A and is adjacent to the first stirring chamber 43A. And a second stirring chamber 44A adjacent to the first stirring chamber 43A. Further, in the developing roll chamber 42A, for example, a layer thickness regulating member 45 for regulating the layer thickness of the developer on the surface of the developing roll 42 is provided when the developing container cover 41B is attached to the developing container main body 41A. Yes.

  The first stirring chamber 43A and the second stirring chamber 44A are partitioned by, for example, a partition wall 41C. Although not shown, the first stirring chamber 43A and the second stirring chamber 44A are arranged in the longitudinal direction of the partition wall 41C (developing device). (Longitudinal direction) Openings are provided at both ends, and the circulation stirring chamber (43A + 44A) is constituted by the first stirring chamber 43A and the second stirring chamber 44A.

  The developing roll 42 is disposed in the developing roll chamber 42 </ b> A so as to face the electrophotographic photoreceptor 10. Although not shown, the developing roll 42 is provided with a sleeve outside a magnetic roll (fixed magnet) having magnetism. The developer in the first stirring chamber 43A is adsorbed on the surface of the developing roll 42 by the magnetic force of the magnetic roll and is transported to the developing area. Further, the developing roller 42 has a roll shaft supported rotatably on the developing container main body 41A. Here, the developing roll 42 and the electrophotographic photoreceptor 10 rotate in the same direction, and the developer adsorbed on the surface of the developing roll 42 at the opposite portion is opposite to the traveling direction of the electrophotographic photoreceptor 10. It is conveyed from the direction to the development area.

  Further, a bias power source (not shown) is connected to the sleeve of the developing roll 42 so that a developing bias is applied (in this embodiment, a direct current component is applied so that an alternating electric field is applied to the developing region. (A bias in which an alternating current component (DC) is superimposed on (AC) is applied).

  In the first stirring chamber 43A and the second stirring chamber 44A, a first stirring member 43 (stirring / conveying member) and a second stirring member 44 (stirring / conveying member) that convey the developer while stirring are disposed. The first stirring member 43 includes a first rotating shaft that extends in the axial direction of the developing roll 42, and an agitating / conveying blade (protrusion) that is helically fixed to the outer periphery of the rotating shaft. Similarly, the second agitating member 44 includes a second rotating shaft and an agitating / conveying blade (protrusion). The stirring member is rotatably supported by the developing container main body 41A. The first stirring member 43 and the second stirring member 44 are arranged such that the developer in the first stirring chamber 43A and the second stirring chamber 44A is conveyed in the opposite directions by rotation thereof. .

  One end of a replenishment conveyance path 46 for supplying replenishment toner including replenishment toner and a replenishment carrier to the second agitation chamber 44A is connected to one end side in the longitudinal direction of the second agitation chamber 44A. A supply toner storage container 47 that stores supply toner is connected to the other end of the path 46.

-Transfer device-
Examples of the primary transfer device 51 and the secondary transfer device 52 include a contact transfer charger using a belt, a roller, a film, a rubber blade, and the like, a scorotron transfer charger using a corona discharge, a corotron transfer charger, and the like. A transfer charger known per se can be used.

  As the intermediate transfer member 50, a belt-like member (intermediate transfer belt) such as polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber containing a conductive agent is used. Further, as the form of the intermediate transfer member, a cylindrical one is used in addition to the belt shape.

-Cleaning device-
The cleaning device 70 includes a housing 71 and a cleaning blade 72 disposed so as to protrude from the housing 71.
The cleaning blade 72 may be supported by the end portion of the casing 71 or may be separately supported by a support member (holder). The form supported at the end of 71 is shown.

The cleaning blade 72 will be described.
The cleaning blade 72 is a plate-like member extending in a direction along the rotation axis of the electrophotographic photosensitive member 10, and the tip portion applies pressure upstream of the rotation direction (arrow a) of the electrophotographic photosensitive member 10. It is provided so that it contacts while hanging.
Examples of the material constituting the cleaning blade 72 include urethane rubber, silicon rubber, fluorine rubber, propylene rubber, and butadiene rubber. Among these, urethane rubber is preferable.
The urethane rubber (polyurethane) is not particularly limited as long as it is usually used for forming polyurethane, for example, a urethane prepolymer comprising a polyol such as a polyester polyol such as polyethylene adipate or polycaprolactone and an isocyanate such as diphenylmethane diisocyanate. For example, it is preferable to use a crosslinking agent such as 1,4-butanediol, trimethylolpropane, ethylene glycol or a mixture thereof as a raw material.

  Next, an image process (image forming method) of the image forming apparatus 101 according to the present embodiment will be described.

  In the image forming apparatus 101 according to the present embodiment, first, the electrophotographic photoreceptor 10 rotates along the direction indicated by the arrow a, and at the same time is charged by the charging device 20.

  The electrophotographic photosensitive member 10 whose surface is charged by the charging device 20 is exposed by the exposure device 30, and a latent image is formed on the surface.

  The portion where the latent image is formed on the electrophotographic photosensitive member 10 approaches the developing device 40, and in the developing device 40, the magnetic brush made of the developer formed on the surface of the developing roll 42 contacts or does not contact the electrophotographic photosensitive member 10. By approaching, toner adheres to the latent image, and a toner image is formed.

  When the electrophotographic photosensitive member 10 on which the toner image is formed further rotates in the direction of arrow a, the toner image is transferred to the outer surface of the intermediate transfer member 50.

  When the toner image is transferred to the intermediate transfer member 50, the recording paper P is supplied to the secondary transfer device 52 by the recording paper supply device 53, and the toner image transferred to the intermediate transfer member 50 is transferred by the secondary transfer device 52. Transferred onto the recording paper P. As a result, a toner image is formed on the recording paper P.

  The toner image is fixed on the recording paper P on which the image is formed by the fixing device 80.

Here, after the toner image is transferred to the intermediate transfer member 50, the toner and discharge products remaining on the surface of the electrophotographic photosensitive member 10 are removed by the cleaning blade 72 of the cleaning device 70 after the transfer. Then, the electrophotographic photosensitive member 10 from which the transfer residual toner and discharge products are removed in the cleaning device 70 is charged again by the charging device 20 and is exposed in the exposure device 30 to form a latent image.
At any time, the replenishment toner is supplied from the replenishment toner storage container 47 through the replenishment conveyance path 46 to the developing device 40 (second stirring chamber 44A).

Further, for example, as illustrated in FIG. 2, the image forming apparatus 101 according to the present embodiment integrally accommodates an electrophotographic photosensitive member 10, a charging device 20, a developing device 40, and a cleaning device 70 in a housing 11. It may be a form provided with the processed process cartridge 101A. The process cartridge 101A integrally contains a plurality of members and is attached to and detached from the image forming apparatus 101. In the image forming apparatus 101 shown in FIG. 2, the replenishment toner storage container 47 is omitted.
The configuration of the process cartridge 101A is not limited to this. For example, the process cartridge 101A only needs to include at least the electrophotographic photosensitive member 10, and for example, the charging device 20, the exposure device 30, the developing device 40, the primary transfer device 51, and the like. At least one selected from the cleaning device 70 may be provided.

  In addition, the image forming apparatus 101 according to the present embodiment is not limited to the above-described configuration. For example, the cleaning is performed around the electrophotographic photosensitive member 10 and downstream of the primary transfer device 51 in the rotation direction of the electrophotographic photosensitive member 10. A cleaning device may be provided with a first static elimination device for aligning the polarity of the remaining toner and facilitating removal with a cleaning brush or the like upstream of the device 70 in the rotational direction of the electrophotographic photosensitive member. In this embodiment, a second static elimination device for neutralizing the surface of the electrophotographic photosensitive member 10 is provided on the downstream side in the rotational direction of the electrophotographic photosensitive member from 70 and upstream in the rotational direction of the electrophotographic photosensitive member from the charging device 20. Also good.

  Further, the image forming apparatus 101 according to the present embodiment is not limited to the above-described configuration, and may employ a known configuration, for example, a method of directly transferring a toner image formed on the electrophotographic photosensitive member 10 to the recording paper P. Alternatively, a tandem image forming apparatus may be employed.

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

<Preparation of toner particles>
(Preparation of Toner 1)
-Preparation of polyester resin dispersion-
・ Terephthalic acid 30mol%
・ Fumaric acid 70mol%
・ Bisphenol A ethylene oxide 2 mol adduct 20 mol%
-Bisphenol A propylene oxide 2 mol adduct 80 mol%
Charge the above monomer into a 5 liter flask equipped with a stirrer, nitrogen inlet tube, temperature sensor, and rectifying column, and increase the temperature to 190 ° C over 1 hour, confirming that the reaction system is being stirred. Then, 1.2 parts by mass of dibutyltin oxide was added.
Further, while distilling off the water produced, it took 6 hours from the same temperature to increase the temperature to 240 ° C., and continued the dehydration condensation reaction at 240 ° C. for another 3 hours. The acid value was 12.0 mg / KOH, and the weight average molecular weight. An amorphous polyester resin of 9700 was obtained.

Subsequently, this was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) at a rate of 100 g / min.
Separately prepared aqueous medium tank is filled with 0.37 wt% diluted ammonia water diluted with ion-exchanged water with reagent-exchanged water, and heated at 120 ° C with a heat exchanger at a rate of 0.1 liter per minute. The amorphous polyester resin 1 melt was transferred to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.).
The Cavitron was operated under conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² to obtain a resin dispersion composed of polyester resin having an average particle size of 0.16 μm and a solid content of 30 parts by mass.

-Preparation of colorant dispersion-
-Cyan pigment (copper phthalocyanine B15: 3: manufactured by Dainichi Seika Co., Ltd.) 45 parts by mass-Ionic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by mass-200 parts by mass of ion-exchanged water Then, it was dispersed for 10 minutes with a homogenizer (IKA Ultra Tarrax) to obtain a colorant dispersion having a center particle size of 168 nm and a solid content of 22.0 parts by mass.

-Preparation of release agent dispersion-
Paraffin wax HNP9 (melting point 75 ° C .: manufactured by Nippon Seiki Co., Ltd.) 45 parts by mass Cationic surfactant Neogen RK (produced by Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by mass 200 parts by mass of ion-exchanged water After heating and dispersing with IKA Ultra Turrax T50, it was dispersed with a pressure discharge type gorin homogenizer to obtain a release agent dispersion having a center diameter of 200 nm and a solid content of 20.0 parts by mass.

-Production of toner particles-
-Polyester resin dispersion 278.9 parts by weight-Colorant dispersion 27.3 parts by weight-Release agent dispersion 35 parts by weight

The above components were mixed and dispersed with Ultra Turrax T50 in a round stainless steel flask. Subsequently, 0.20 part by mass of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. While stirring the flask in a heating oil bath, it was heated to 42 ° C. as temperature TE1. After holding at 42 ° C. for 60 minutes, 70.0 parts by mass of the polyester resin dispersion was added thereto.
Thereafter, the pH of the system was adjusted to 9.0 with a 0.5 mol / l sodium hydroxide aqueous solution, and then the stainless steel flask was sealed and heated to 85 ° C. as a temperature TE2 while continuing stirring using a magnetic seal. For 3 hours as time TI2.
After completion of the reaction, the mixture was cooled, filtered, washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 1 L of ion exchange water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes.
This was repeated five more times, and when the pH of the filtrate became 7.5 and the electric conductivity was 7.0 μS / cmt, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. Vacuum drying was then continued for 12 hours.

  Through the above steps, toner particles 1 were obtained. The volume average particle diameter D50 of the toner particles 1 is 3.6 μm, and the particle size distribution coefficient GSD is 1.14. Further, the circularity of the toner particles 1 was 0.973.

(Preparation of toner particles 2 to 4)
According to Table 1, toner particles 2 to 4 having the volume average particle diameters shown in Table 1 were obtained in the same manner as the toner particles 1 except that the production conditions of the toner particles 1 were changed. Specifically, it is as follows.

-Production of toner particles 2-
-Polyester resin dispersion 278.9 parts by mass-Colorant dispersion 27.3 parts by mass-Release agent dispersion 35 parts by mass The above components were mixed and dispersed in a round stainless steel flask using Ultra Turrax T50. Subsequently, 0.20 part by mass of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. While stirring the flask in a heating oil bath, it was heated to 45 ° C. as temperature TE1. After holding at 45 ° C. for 60 minutes, 70.0 parts by mass of the polyester resin dispersion was added thereto.
Thereafter, the pH of the system was adjusted to 9.0 with a 0.5 mol / l sodium hydroxide aqueous solution, and then the stainless steel flask was sealed and heated to 85 ° C. as a temperature TE2 while continuing stirring using a magnetic seal. For 3 hours as time TI2.
After completion of the reaction, the mixture was cooled, filtered, washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 1 L of ion exchange water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes.
This was repeated five more times, and when the pH of the filtrate became 7.5 and the electric conductivity was 7.0 μS / cmt, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. Vacuum drying was then continued for 12 hours.

  Through the above steps, toner particles 2 were obtained. Toner particles 2 had a volume average particle diameter D50 of 4.2 μm and a particle size distribution coefficient GSD of 1.14. Further, the circularity of the toner particles 2 was 0.972.

-Production of toner particles 3-
-Polyester resin dispersion 278.9 parts by mass-Colorant dispersion 27.3 parts by mass-Release agent dispersion 35 parts by mass The above components were mixed and dispersed in a round stainless steel flask using Ultra Turrax T50. Subsequently, 0.20 part by mass of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. While stirring the flask in a heating oil bath, it was heated to 42 ° C. as temperature TE1. After holding at 42 ° C. for 60 minutes, 70.0 parts by mass of the polyester resin dispersion was added thereto.
Thereafter, the pH of the system was adjusted to 9.0 with a 0.5 mol / l sodium hydroxide aqueous solution, and then the stainless steel flask was sealed and heated to 85 ° C. as a temperature TE2 while continuing stirring using a magnetic seal. For 4 hours as time TI2.
After completion of the reaction, the mixture was cooled, filtered, washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 1 L of ion exchange water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes.
This was repeated five more times, and when the pH of the filtrate became 7.5 and the electric conductivity was 7.0 μS / cmt, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. Vacuum drying was then continued for 12 hours.

  Through the above steps, toner particles 3 were obtained. Toner particles 3 had a volume average particle diameter D50 of 3.6 μm and a particle size distribution coefficient GSD of 1.13. Further, the circularity of the toner particles 3 was 0.994.

-Production of toner particles 4-
-Production of toner particles 2-
-Polyester resin dispersion 278.9 parts by mass-Colorant dispersion 27.3 parts by mass-Release agent dispersion 35 parts by mass The above components were mixed and dispersed in a round stainless steel flask using Ultra Turrax T50. Subsequently, 0.20 part by mass of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. While stirring the flask in a heating oil bath, it was heated to 48 ° C. as temperature TE1. After maintaining at 48 ° C. for 60 minutes, 70.0 parts by mass of the polyester resin dispersion was added thereto.
Thereafter, the pH of the system was adjusted to 9.0 with a 0.5 mol / l sodium hydroxide aqueous solution, and then the stainless steel flask was sealed and heated to 85 ° C. as a temperature TE2 while continuing stirring using a magnetic seal. For 3 hours as time TI2.
After completion of the reaction, the mixture was cooled, filtered, washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 1 L of ion exchange water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes.
This was repeated five more times, and when the pH of the filtrate became 7.5 and the electric conductivity was 7.0 μS / cmt, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. Vacuum drying was then continued for 12 hours.

  Through the above steps, toner particles 4 were obtained. Toner particles 4 had a volume average particle diameter D50 of 5.3 μm and a particle size distribution coefficient GSD of 1.15. Further, the circularity of the toner particles 4 was 0.971.

<Preparation of external additive>
(Preparation of silica particles 1)
-Granulation process-
・ Alkaline catalyst solution preparation process (Preparation of alkali catalyst solution)
Put 300 parts by mass of methanol and 47.7 parts by mass of 10% ammonia water in a 3 L glass reaction vessel with a metal stir bar, dropping nozzle (Teflon (registered trademark) micro tube pump) and thermometer. The mixture was stirred and mixed to obtain an alkali catalyst solution.

・ Particle production process (preparation of silica particle suspension)
Next, the temperature of the alkali catalyst solution was adjusted to 25 ° C., and the alkali catalyst solution was purged with nitrogen. Then, while stirring the alkali catalyst solution, 450 parts by mass of tetramethoxysilane (TMOS) and 270 parts by mass of ammonia water having a catalyst (NH ₃ ) concentration of 4.44% were simultaneously added dropwise at the following supply amount. A suspension of silica particles (silica particle suspension) was obtained.
Here, the supply amount of tetramethoxysilane was 6.37 parts by mass / min, and the supply amount of 4.44% ammonia water was 3.82 parts by mass / min.
When the particles of the obtained silica particle suspension were measured with the particle size measuring apparatus described above, the volume average particle diameter (D50v) was 68 nm.

-Drying process-
Next, the obtained suspension of hydrophilic silica particles (hydrophilic silica particle dispersion) was dried by spray drying to remove the solvent to obtain hydrophilic silica particle powder.

-Hydrophobization process-
100 parts by mass of the obtained hydrophilic silica particle powder was put in a mixer and stirred at 200 rpm while heating to 200 ° C. in a nitrogen atmosphere, and hexamethyldisilazane (HMDS) was added to the hydrophilic silica particle powder in 30 parts. Part by mass was dropped and reacted for 2 hours. Then, the powder of the hydrophobic silica particle which was cooled and hydrophobized was obtained.

  The powder of hydrophobic silica particles obtained through the above steps was designated as silica particles 1. The circularity of the silica particles 1 was 0.782.

(Preparation of silica particles 2)
-Granulation process-
・ Alkaline catalyst solution preparation process (Preparation of alkali catalyst solution)
Put 300 parts by mass of methanol and 46.9 parts by mass of 10% ammonia water in a 3 L glass reaction vessel with a metal stir bar, dropping nozzle (Teflon (registered trademark) micro tube pump), and thermometer. The mixture was stirred and mixed to obtain an alkali catalyst solution.

・ Particle production process (preparation of silica particle suspension)
Next, the temperature of the alkali catalyst solution was adjusted to 25 ° C., and the alkali catalyst solution was purged with nitrogen. Then, while stirring the alkali catalyst solution, 450 parts by mass of tetramethoxysilane (TMOS) and 270 parts by mass of ammonia water having a catalyst (NH ₃ ) concentration of 4.44% were simultaneously added dropwise at the following supply amount. A suspension of silica particles (silica particle suspension) was obtained.
Here, the supply amount of tetramethoxysilane was 5.52 parts by mass / min, and the supply amount of 4.44% ammonia water was 3.31 parts by mass / min.
When the particles of the obtained silica particle suspension were measured with the particle size measuring apparatus described above, the volume average particle diameter (D50v) was 42 nm.

-Drying process-
Next, the obtained suspension of hydrophilic silica particles (hydrophilic silica particle dispersion) was dried by spray drying to remove the solvent to obtain hydrophilic silica particle powder.

-Hydrophobization process-
100 parts by mass of the obtained hydrophilic silica particle powder was put in a mixer and stirred at 200 rpm while heating to 200 ° C. in a nitrogen atmosphere, and hexamethyldisilazane (HMDS) was added to the hydrophilic silica particle powder in 30 parts. Part by mass was dropped and reacted for 2 hours. Then, the powder of the hydrophobic silica particle which was cooled and hydrophobized was obtained.

  The powder of hydrophobic silica particles obtained through the above steps was designated as silica particles 2. The circularity of the silica particles 2 was 0.816.

(Preparation of silica particles 3)
-Granulation process-
・ Alkaline catalyst solution preparation process (Preparation of alkali catalyst solution)
Put 300 parts by mass of methanol and 47.7 parts by mass of 10% ammonia water in a 3 L glass reaction vessel with a metal stir bar, dropping nozzle (Teflon (registered trademark) micro tube pump) and thermometer. The mixture was stirred and mixed to obtain an alkali catalyst solution.

・ Particle production process (preparation of silica particle suspension)
Next, the temperature of the alkali catalyst solution was adjusted to 25 ° C., and the alkali catalyst solution was purged with nitrogen. Then, while stirring the alkali catalyst solution, 450 parts by mass of tetramethoxysilane (TMOS) and 270 parts by mass of ammonia water having a catalyst (NH ₃ ) concentration of 4.44% were simultaneously added dropwise at the following supply amount. A suspension of silica particles (silica particle suspension) was obtained.
Here, the supply amount of tetramethoxysilane was 1.58 parts by mass / min, and the supply amount of 4.44% ammonia water was 0.95 parts by mass / min.
When the particles of the obtained silica particle suspension were measured with the particle size measuring apparatus described above, the volume average particle diameter (D50v) was 68 nm.

-Drying process-
Next, the obtained suspension of hydrophilic silica particles (hydrophilic silica particle dispersion) was dried by spray drying to remove the solvent to obtain hydrophilic silica particle powder.

-Hydrophobization process-
100 parts by mass of the obtained hydrophilic silica particle powder was put in a mixer and stirred at 200 rpm while heating to 200 ° C. in a nitrogen atmosphere, and hexamethyldisilazane (HMDS) was added to the hydrophilic silica particle powder in 30 parts. Part by mass was dropped and reacted for 2 hours. Then, the powder of the hydrophobic silica particle which was cooled and hydrophobized was obtained.

  The powder of hydrophobic silica particles obtained through the above steps was designated as silica particles 3. The circularity of the silica particles 3 was 0.983.

(Preparation of silica particles 4)
Fumed silica particles (“R8200” manufactured by Aerosil Co., Ltd., HMDS surface treatment, volume average particle size 12 nm, circularity 0.948) were prepared, and this was designated as silica particles 4.

<Creation of carrier>
(Preparation of carrier 1)
・ Soken Chemical Co., Ltd. “Polymethyl methacrylate (PMMA) resin (Mw 72,000, Mn 36,000): 3 parts by mass • Wako Pure Chemical Industries, Ltd. Toluene (special grade): 30 parts by mass Magnetic powder “Mn—Mg ferrite core (average particle size 23 μm, saturation magnetization 55 A / m ² / kg (at 1 kOe), true specific gravity 4.6 g / cm ³ )”: 100 parts by mass Of the above composition, first, PMMA resin Is dissolved in toluene to prepare a toluene solution of PMMA resin.
Next, a ferrite core (magnetic powder) as a core material is put into a kneader heated to 80 ° C. and stirred.
When the ferrite core reaches 50 ° C., a toluene solution of PMMA is added, sealed, and stirred for 10 minutes.
Next, while stirring, a vacuum is applied to evaporate the toluene. After 30 minutes, release the vacuum and remove.
Then, after allowing to cool to 30 ° C., sieving with 45 μm was carried out to obtain Carrier 1 having an average particle size of 24 μm.

(Production of carriers 2 to 3)
Carriers 2 to 3 having the volume average particle diameters shown in Table 1 were obtained in the same manner as Carrier 1 except that the production conditions of Carrier 1 were changed according to Table 1. Specifically, it is as follows.

-Production of carrier 2-
・ Soken Chemical Co., Ltd. “Polymethyl methacrylate (PMMA) resin (Mw 72,000, Mn 36,000): 3 parts by mass • Wako Pure Chemical Industries, Ltd. Toluene (special grade): 30 parts by mass Magnetic powder “Mn—Mg ferrite core (average particle size 30 μm, saturation magnetization 55 A / m ² / kg (at 1 kOe), true specific gravity 4.6 g / cm ³ )”: 100 parts by mass Of the above composition, first, PMMA resin Is dissolved in toluene to prepare a toluene solution of PMMA resin.
Next, a ferrite core (magnetic powder) as a core material is put into a kneader heated to 80 ° C. and stirred.
When the ferrite core reaches 50 ° C., a toluene solution of PMMA is added, sealed, and stirred for 10 minutes.
Next, while stirring, a vacuum is applied to evaporate the toluene. After 30 minutes, release the vacuum and remove.
And after allowing to cool to 30 ° C., 45 μm sieving was carried out to obtain Carrier 2 having an average particle size of 32 μm.

-Production of carrier 3-
・ Soken Chemical Co., Ltd. “Polymethyl methacrylate (PMMA) resin (Mw 72,000, Mn 36,000): 3 parts by mass • Wako Pure Chemical Industries, Ltd. Toluene (special grade): 30 parts by mass Magnetic powder “Mn—Mg ferrite core (average particle size 38 μm, saturation magnetization 55 A / m ² / kg (at 1 kOe), true specific gravity 4.6 g / cm ³ )”: 100 parts by mass Of the above composition, first, PMMA resin Is dissolved in toluene to prepare a toluene solution of PMMA resin.
Next, a ferrite core (magnetic powder) as a core material is put into a kneader heated to 80 ° C. and stirred.
When the ferrite core reaches 50 ° C., a toluene solution of PMMA is added, sealed, and stirred for 10 minutes.
Next, while stirring, a vacuum is applied to evaporate the toluene. After 30 minutes, release the vacuum and remove.
Then, after allowing to cool to 30 ° C., 45 μm sieving was carried out to obtain Carrier 3 having an average particle size of 40 μm.

<Production of developer>
(Preparation of developer 1)
Toner particles 1: 100 parts by mass, silica particles 1: 4.4 parts by mass, and titania particles 1 (manufactured by “P25” AlloAzil, volume average particle size 20 nm, surface treatment with octylsilane): After adding 1.5 parts by mass and mixing under the external addition conditions of stirring blade rotation speed = 3760 rpm, stirring blade diameter = 0.17 mm, stirring time = 15 minutes using a 5 liter Henschel mixer, 45 μm Toner 1 was prepared by removing coarse particles using a sieve with openings.
The mixing strength of the toner particles and the external additive (hereinafter “mixing strength”) was 2.30E + 10. However, it is a value calculated by the formula: mixing intensity = [stirring blade rotation speed (rpm)] ³ × [diameter of stirring blade (m)] ² × [stirring time (minutes)].
Then, 10 parts by weight of toner 1 and 90 parts by weight of carrier 1 were blended with a V-type blender at a stirring speed of 20 rpm for 15 minutes to prepare Developer 1.

(Developers 2-9, comparative developers C1-C4)
Toner particles 2 to 9 and comparative toner C1 are the same as toner particles 1 except that the types and amounts of toner particles, silica particles, and titania particles and external addition conditions are changed according to Tables 2 to 3. -C4 was produced.
Then, according to Table 2, Developers 2 to 9 and Comparative Developers C1 to C4 were produced in the same manner as Developer 1, except that the type of carrier and the mass ratio with the toner were changed.

<Examples 1-9, Comparative Examples 1-5>
The developer according to Table 2 is accommodated in a developing device of a modified machine of “Apeos Port IV C5575” manufactured by Fuji Xerox Co., Ltd., and 250 g is filled in the toner cartridge as a replenishing toner, and the following evaluation is performed. went.

[Evaluation]
With the above-mentioned “Apeos Port IV C5575” modified machine, the following image output conditions (1) according to the image density (area coverage) of halftone images and the number of output sheets (number of output sheets of A4 paper) shown below at 22 ° C. and 50% environment ), (2), and (3) were repeatedly output in this order.
Then, in the “Apeos Port IV C5575” modified machine, when the empty display (Empty display) of the toner cartridge was shown, the toner cartridge was taken out, and the amount of the replenishment toner remaining on the toner cartridge was measured.
Further, when the full container display (Full display) of the collection container (collection box) for collecting the collected toner was shown, the collection container was taken out and the amount of collected toner collected in the collection container was measured.
(1) Image density (area coverage) 5,000 halftone images with 1% output (2) Image density (area coverage) 5,000 halftone images with 5% output (3) Image density (area coverage) ) Output 5,000 20% halftone images

  Details of each developer (details of replenishment toner) and details of the collected toner are listed in Tables 1 to 4. The evaluation results are shown in Table 4.

From the above results, it can be seen that in this embodiment, compared to the comparative example, the remaining amount of replenishment toner remaining in the toner cartridge at the time when empty display (Empty display) of the toner cartridge is displayed is small.
Further, in this embodiment, it can be seen that the amount of collected toner collected in the collection container at the time when the full container display (Full display) of the collection container (collection box) for collecting the collected toner is shown is large.

DESCRIPTION OF SYMBOLS 10 Electrophotographic photosensitive member, 10A Electrophotographic photosensitive member, 10B Electrophotographic photosensitive member, 20 Charging device, 30 Exposure device, 40 Developing device, 41 Developing container, 41A Developing container main body, 41B Developing container cover, 41C Partition wall, 42 Developing Roll, 42A Developing roll chamber, 43 Stirring member, 43A Stirring chamber, 44 Stirring member, 44A Stirring chamber, 45 Layer thickness regulating member, 46 Replenishing transport path, 47 Replenishing toner container, 50 Intermediate transfer member, 50A Supporting roller, 50B Support roller, 50C back roller, 50D drive roller, 51 primary transfer device, 52 secondary transfer device, 53 recording paper supply device, 53A transport roller, 53B guide plate, 54 intermediate transfer member cleaning device, 70 cleaning device, 71 housing 72 Cleaning blade 80 Fixing device 81 Fixing low , 82 Conveyance belt, 101 Image forming apparatus, 101A Process cartridge

Claims (4)

An image carrier,
Charging means for charging the surface of the image carrier;
Latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier;
Silica particles containing toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive, and having a BET specific surface area of 2.9 m ² / g to 4.2 m ² / g A developer having a toner having a liberation ratio of 0.64% by mass or more and 2.60% by mass or less and a carrier having a volume average particle diameter of 10 μm or more and 32 μm, and containing the developer by the developer. Developing means for developing the electrostatic latent image formed on the toner image to form a toner image;
Transfer means for transferring the toner image formed on the image carrier to a recording medium;
Cleaning means having a cleaning blade for cleaning the toner remaining on the surface of the image carrier;
The developing means includes toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive, and a BET specific surface area of 2.9 m ² / g or more and 4.2 m ² / g or less. Toner replenishing means for replenishing replenishment toner having a liberation rate of the silica particles of 0.64% by mass or more and 2.60% by mass or less;
With
The BET specific surface area of the collected toner collected by cleaning of the cleaning means is 1.5 m ² / g or more and 2.8 m ² / g or less, and the liberation rate of silica particles is 0.13 mass% or more and 2.00 mass% or less. An image forming apparatus having an angle of repose smaller than the angle of repose of the replenishing toner. A charging step for charging the surface of the image carrier;
A latent image forming step of forming an electrostatic latent image on the surface of the charged image carrier;
Silica particles comprising toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive and having a BET specific surface area of 2.8 m ² / g or more and 4.2 m ² / g or less The electrostatic image formed on the image carrier by a developer having a toner having a liberation ratio of 0.64% by mass or more and 2.60% by mass or less and a carrier having a volume average particle size of 10 μm or more and 32 μm. A developing step of developing a latent image to form a toner image;
A transfer step of transferring the toner image formed on the image carrier to a recording medium;
A cleaning step of cleaning the toner remaining on the surface of the image carrier with a cleaning blade;
The developing means includes toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive, and a BET specific surface area of 2.8 m ² / g or more and 4.2 m ² / g or less. A toner replenishing step of replenishing a replenishment toner having a silica particle liberation rate of 0.64% by mass or more and 2.60% by mass or less;
With
The BET specific surface area of the collected toner collected by the cleaning in the cleaning step is 1.5 m ² / g or more and 2.8 m ² / g or less, and the liberation rate of the silica particles is 0.13 mass% or more and 2.00 mass% or less. An image forming method in which the angle of repose is smaller than the angle of repose of the replenishing toner. Including toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive,
The BET specific surface area is 2.8 m ² / g or more and 4.2 m ² / g or less, the liberation rate of silica particles is 0.64 mass% or more and 2.60 mass% or less, and the angle of repose is 40 ° or less. A toner for developing an electrostatic latent image. Including toner particles having a volume average particle size of 2.0 μm or more and 5.0 μm or less and silica particles as an external additive,
The BET specific surface area is 1.5 m ² / g or more and 2.8 m ² / g or less, the release rate of the silica particles is 0.13 mass% or more and 2.00 mass% or less, and the angle of repose is 35 ° or less. Yes,
A collected toner for developing an electrostatic latent image, which is collected by cleaning the toner remaining on the surface of the image carrier after the toner image formed on the image carrier by the toner is transferred to a recording medium.