Process cartridge

Abstract

To provide a cartridge that is further developed from a conventional cartridge.SOLUTION: A cartridge has a photoconductor drum, a developing roller, a feed roller, a developing chamber, a developing blade including an elastic blade and a support part, and a storage part of toner having a particle diameter R. The storage part and the developing chamber communicate with each other. A contact point of the developing blade and the developing roller is below a horizontal line passing through a rotation axis of the developing roller. Fluorine is present inside hydrotalcite particles of a toner external additive. When, at a nip formed by the elastic blade and the developing roller, an end on the upstream side in the direction of rotation of the developing roller is defined as a point D, a point on the most free end side of the elastic blade as a point B, a point at which a perpendicular from the point B and the developing roller intersect each other as a point E, a point on the most free end side among points on a surface of the elastic blade having a distance R from a surface of the developing roller as a point F, and a point on a straight line BE having the distance R from the surface of the developing roller as a point G, the distance between G and F is equal to or more than R.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a process cartridge. [Background technology]

[0002] In an image forming apparatus such as a printer using an electrophotographic image forming method (electrophotographic process), an electrophotographic photoconductor (hereinafter referred to as "photoconductor") serving as an image carrier is uniformly charged, and the charged photoconductor is selectively exposed to light to form an electrostatic image on the photoconductor. The electrostatic image formed on the photoconductor is visualized as a toner image using toner as a developer. The toner image formed on the photoconductor is then transferred to a recording material such as recording paper or a plastic sheet, and the toner image transferred to the recording material is fixed to the recording material by applying heat or pressure, thereby recording an image.

[0003] Such an image forming apparatus generally requires the supply of developer and the maintenance of various process means. In order to facilitate the supply of developer and the maintenance of various process means, a process cartridge has been put into practical use, in which a photoconductor, a charging means, a developing means, a cleaning means, etc. are integrated into a frame to form a cartridge that is detachably mountable to the main body of the image forming apparatus. The process cartridge system makes it possible to provide an image forming apparatus with excellent usability.

[0004] In recent years, color image forming apparatuses that form color images using multiple color developers have become widespread. As color image forming apparatuses, there are known so-called in-line type image forming apparatuses in which photoconductors corresponding to the respective image forming operations using multiple color developers are arranged in a line along the surface movement direction of a transfer target body to which a toner image is transferred. In-line type color image forming apparatuses include those in which multiple photoconductors are arranged in a line in a direction (for example, horizontal direction) that intersects with the vertical direction (gravity direction). The in-line type is a preferred image forming method in that it is easy to meet the demands for high-speed image formation and deployment to multifunction printers.

[0005] Further, there is an image forming apparatus in which a photoconductor is disposed below an intermediate transfer body as a transfer recipient, or below a recording material carrier that transports a recording material as a transfer recipient (JP 2011-253203 A).

[0006] When the photoconductor is disposed below the intermediate transfer body or the recording material carrier, for example, the fixing device and the developing device (or the exposure device) can be disposed at positions separated from each other in the main body of the image forming apparatus with the intermediate transfer body or the recording material carrier sandwiched therebetween, which has the advantage that the developing device (or the exposure device) is less susceptible to the heat of the fixing device. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2011-253203 A Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a cartridge which is an improvement over conventional cartridges. [Means for solving the problem]

[0009] The present invention has the following configuration. A process cartridge that can be mounted in an image forming apparatus, a photosensitive drum as an image carrier, a developing roller for developing a toner image on the photosensitive drum, a supply roller for supplying toner to the developing roller; a developing chamber having a support portion for axially supporting the developing roller and the supply roller; a developing blade for regulating the thickness of a toner layer on the developing roller; a toner having toner particles having a volume average particle size R and an external additive; a toner storage section for storing the toner, the toner storage section is configured to communicate with the developing chamber through a communication port, the developing roller is configured so that the moving direction of the surface of the developing roller is opposite to the moving direction of the surface of the supply roller at the contact position with the supply roller; in a cross section of the process cartridge in a plane perpendicular to the rotation axis of the developing roller when the process cartridge is mounted in the main body of the image forming apparatus, a location where the developing blade contacts the developing roller is vertically below a horizontal line H1 passing through a center of the rotation axis of the developing roller; A driving force receiving portion is provided. a first driving force transmitting portion for transmitting the driving force from the driving force receiving portion to the supply roller; a second driving force transmission portion provided on the supply roller for transmitting the driving force received by the first driving force transmission portion to the developing roller; a third driving force transmission unit provided on the developing roller and configured to transmit a driving force from the second driving force transmission unit to the developing roller; A process cartridge having the toner contains hydrotalcite particles as the external additive, In a line analysis in a STEM-EDS mapping analysis of the toner, fluorine is present inside the hydrotalcite particles, The developing blade is made of a plate-shaped metallic elastic blade and a blade support portion for supporting the elastic blade. In a cross section of the process cartridge taken along a plane perpendicular to the rotation axis of the developing roller, The elastic blade is in contact with the developing roller to form a nip N1. A point on the elastic blade at the end of the nip N1 on the upstream side in the rotation direction of the developing roller is defined as point D. A point on the elastic blade that is closest to the surface of the developing roller is designated as point B. A point E is a point where a perpendicular line drawn from point B to the surface of the developing roller intersects with the surface of the developing roller. a point F on the surface of the elastic blade that is closest to the free end of the elastic blade and has a distance R from the surface of the developing roller; When the point G on the straight line BE is at a distance R from the surface of the developing roller, the distance GF is equal to or greater than R. The process cartridge is characterized in that The present invention also has the following configuration. A process cartridge that can be mounted in an image forming apparatus, a photosensitive drum as an image carrier, a developing roller for developing a toner image on the photosensitive drum, a supply roller for supplying toner to the developing roller; a developing chamber having a support portion for axially supporting the developing roller and the supply roller; a developing blade for regulating the thickness of a toner layer on the developing roller; a toner having toner particles having a volume average particle size R and an external additive; a toner storage section for storing the toner, the toner storage section is configured to communicate with the developing chamber through a communication port, The direction of movement of the surface of the developing roller at the contact position with the supply roller is as follows: The direction of movement of the surface of the supply roller is opposite to the direction of movement of the supply roller. The developing blade is made of a plate-shaped metallic elastic blade and a blade support portion for supporting the elastic blade. In a cross section of the process cartridge taken along a plane perpendicular to the rotation axis of the developing roller, a straight line A connecting the rotational centers of the supply roller and the developing roller is inclined at an angle of approximately 9.85° from the horizontal, the rotational axis center of the supply roller is below the rotational axis center of the developing roller, and the rotational axis center of the photosensitive drum is above the straight line A. In this state, the location where the elastic blade contacts the developing roller is below the rotational axis center of the developing roller, A driving force receiving portion is provided. a first driving force transmitting portion for transmitting the driving force from the driving force receiving portion to the supply roller; a second driving force transmission portion provided on the supply roller for transmitting the driving force received by the first driving force transmission portion to the developing roller; a third driving force transmission unit provided on the developing roller and configured to transmit a driving force from the second driving force transmission unit to the developing roller; A process cartridge, the toner contains hydrotalcite particles as the external additive, In a line analysis in a STEM-EDS mapping analysis of the toner, fluorine is present inside the hydrotalcite particles, In a cross section of the process cartridge taken along a plane perpendicular to the rotation axis of the developing roller, The elastic blade is in contact with the developing roller to form a nip N1. A point on the elastic blade at the end of the nip N1 on the upstream side in the rotation direction of the developing roller is defined as point D. A point on the elastic blade that is closest to the surface of the developing roller is designated as point B. A point E is a point where a perpendicular line drawn from point B to the surface of the developing roller intersects with the surface of the developing roller. a point F on the surface of the elastic blade that is closest to the free end of the elastic blade and has a distance R from the surface of the developing roller; When the point G on the straight line BE is at a distance R from the surface of the developing roller, the distance GF is equal to or greater than R. The process cartridge is characterized in that Effect of the Invention

[0010] As described above, according to the present invention, it is possible to provide a cartridge which is an improved version of the conventional cartridge. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment to which the present invention can be applied; [Diagram 2] 1 is a schematic cross-sectional view of a process cartridge according to an embodiment to which the present invention can be applied; [Diagram 3] 1 is a conceptual cross-sectional view in a lateral direction of a developing blade according to an embodiment to which the present invention can be applied; [Figure 4]FIG. 2A is a schematic cross-sectional view illustrating a contact state between a developing blade and a developing roller according to an embodiment to which the present invention can be applied; FIG. 2B is a schematic cross-sectional view illustrating a contact state between a developing blade and a developing roller according to a comparative example of the present invention; [Diagram 5] FIG. 1 is a diagram for explaining a method of inputting driving force to a toner supply roller according to an embodiment to which the present invention can be applied; [Figure 6] FIG. 2 is a diagram showing the movement of toner in a developing device according to an embodiment to which the present invention can be applied; [Figure 7] FIG. 1 is a diagram for explaining the positional relationship between the inner wall of a developing chamber and the supporting end of a developing blade in an embodiment to which the present invention can be applied. [Figure 8] FIG. 1 is a schematic cross-sectional view of a contact portion between a developing roller and a developing blade, illustrating the movement of toner regulated by the developing blade in an embodiment to which the present invention can be applied; [Figure 9] Schematic diagram of on-line analysis of external additives [Figure 10] FIG. 13 is a cross-sectional conceptual diagram of a developing blade in a lateral direction when the tip of the developing blade is bent in a modified example of an embodiment to which the present invention can be applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The developing device, process cartridge, and image forming apparatus according to the present invention will be described in more detail below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, and relative positions of the components described in this embodiment are not intended to limit the scope of the present invention to those alone. Furthermore, the materials, shapes, and the like of the members once described in the following description are the same as those described initially unless otherwise specified. Well-known or publicly known technologies in the relevant technical field can be applied to configurations and processes not particularly shown or described. Furthermore, duplicated descriptions may be omitted.

[0013] <Example> [Image forming device] Fig. 1 is a diagram showing a schematic configuration of an image forming apparatus 100 of this embodiment in a position where it is placed on a horizontal surface, similar to when it is actually used. The image forming apparatus 100 of this embodiment is an in-line type full-color laser printer that employs an intermediate transfer method. As shown in Fig. 1, four detachable process cartridges 70 (70Y, 70M, 70C, 70K) are mounted by mounting members (not shown). The upstream side of the process cartridges 70 in the mounting direction of the image forming apparatus 100 is defined as the front side, and the downstream side of the mounting direction is defined as the back side.

[0014] Each process cartridge 70 is provided with an electrophotographic photosensitive drum (hereinafter referred to as photosensitive drum) 1 (1a, 1b, 1c, 1d). In addition, in each process cartridge 70, process means such as a charging roller 2 (2a, 2b, 2c, 2d), a developing roller 25 (25a, 25b, 25c, 25d), and a cleaning member 6 (6a, 6b, 6c, 6d) are integrally arranged around the photosensitive drum 1. The charging roller 2 uniformly charges the surface of the photosensitive drum 1. In this embodiment, the charging roller 2 is negatively charged. The developing roller 25 develops the latent image formed on the photosensitive drum 1 with a developer (hereinafter referred to as toner) to make it visible. The normal polarity of the toner in this embodiment is negative. And the cleaning member 6 removes the toner remaining on the photosensitive drum 1 after the toner image formed on the photosensitive drum 1 is transferred to a recording medium. The detailed configurations and positional relationships of the photosensitive drum 1, the charging roller 2, the developing roller 25, and the cleaning member 6 will be described later with reference to FIG.

[0015] Further, below the process cartridge 70 in the direction of gravity, a scanner unit 3 is provided for selectively exposing the photosensitive drum 1 based on image information and forming a latent image on the photosensitive drum 1.

[0016] A cassette 17 containing a recording medium S is attached to the lower part of the apparatus main body 100a. A recording medium conveying means is provided so that the recording medium S passes through a secondary transfer roller 69 and a fixing unit 74 and is conveyed to the upper part of the apparatus main body 100a. An intermediate transfer unit 5 is provided above the process cartridges 70 (70Y, 70M, 70C, 70K) as an intermediate transfer means for transferring the toner images formed on the photosensitive drums 1 (1a, 1b, 1c, 1d). The intermediate transfer unit 5 has a drive roller 56, a driven roller 57, primary transfer rollers 58 (58a, 58b, 58c, 58d) at positions facing the photosensitive drums 1 of the respective colors, and an opposing roller 59 at a position facing the secondary transfer roller 69, and a transfer belt 50 is stretched around the intermediate transfer unit 5. The transfer belt 50 moves circulating so as to face and contact all the photosensitive drums 1, and a voltage is applied to the primary transfer rollers 58 (58a, 58b, 58c, 58d) to perform primary transfer from the photosensitive drums 1 onto the transfer belt 50. The toner on the transfer belt 50 is transferred onto the recording medium S by applying a voltage to an opposing roller 59 and a secondary transfer roller 69 disposed within the transfer belt 50 .

[0017] In forming an image, each photosensitive drum 1 is rotated, and the photosensitive drum 1, which is uniformly charged by the charging roller 2, is selectively exposed to light from the scanner unit 3. As a result, an electrostatic latent image is formed on the photosensitive drum 1. The latent image is developed by the developing roller 25. As a result, a toner image of each color is formed on each photosensitive drum 1. In synchronization with this image formation, the pair of registration rollers 55 conveys the recording medium S to a secondary transfer position where the opposing roller 59 and the secondary transfer roller 69 are in contact with each other with the transfer belt 50 interposed therebetween. Then, a transfer bias voltage is applied to the secondary transfer roller 69, so that the toner image of each color on the transfer belt 50 is secondarily transferred to the recording medium S. As a result, a color image is formed on the recording medium S. The recording medium S on which the color image has been formed is heated and pressed by the fixing unit 74, so that the toner image is fixed. Thereafter, the recording medium S is discharged to the discharge unit 75 by the discharge roller 72. The fixing unit 74 is disposed in the upper part of the device main body 100a.

[0018] [Process cartridge] Next, a process cartridge 70 embodying the present invention will be described with reference to Fig. 2. Fig. 2 is a main cross section of the process cartridge 70 containing toner, in a position in which it is mounted in the image forming apparatus 100. The cartridge 70Y containing yellow toner, the cartridge 70M containing magenta toner, the cartridge 70C containing cyan toner, and the cartridge 70K containing black toner all have the same configuration.

[0019] The process cartridge 70 includes a cleaning unit 26 and a developing unit 4. The cleaning unit 26 includes a photosensitive drum 1, a charging roller 2, and a cleaning member 6. The developing unit 4 includes a developing roller 25.

[0020] As described above, the charging roller 2 and cleaning member 6 are disposed on the periphery of the photosensitive drum 1. The cleaning member 6 is composed of an elastic member 7 made of a rubber blade and a cleaning support member 8. The tip of the elastic member 7 made of a rubber blade is disposed in contact with the photosensitive drum 1 in the counter direction to the rotation direction of the photosensitive drum 1. Residual toner removed from the surface of the photosensitive drum 1 by the cleaning member 6 falls into a removed toner chamber 27.

[0021] The photosensitive drum 1 is rotated in response to an image forming operation by transmitting the driving force of a main body drive motor (not shown) serving as a drive source to the cleaning unit 26. At this time, a drum coupling fixed to the longitudinal end of the photosensitive drum 1 engages with a main body side coupling present on the longitudinal axis of the photosensitive drum 1, so that the driving force is input to the photosensitive drum 1. The charging roller 2 is rotatably attached to the cleaning unit 26 via a charging roller bearing, and is pressed toward the photosensitive drum 1 by a charging roller pressure member, and rotates following the photosensitive drum 1.

[0022] The developing unit 4 is composed of a developing roller 25 which rotates in contact with the photosensitive drum 1, and a developing frame 31 which supports the developing roller 25. The developing frame 31 is composed of a developing chamber 31b and a toner containing chamber 31a (toner containing section).

[0023] On the circumference of the developing roller 25, there are disposed a toner supply roller 34 which rotates in the direction of the arrow C in contact with the developing roller 25, and a developing blade 35 for regulating the toner layer on the developing roller 25. In this embodiment, the outer diameter of the developing roller 25 is 12 mm, and the outer diameter of the toner supply roller 34 is 13.2 mm. When the process cartridge 70 is in a position mounted in the image forming apparatus 100, the angle α between the horizontal line H and a straight line A which connects the rotation center 25e of the developing roller 25 and the rotation center 34e of the toner supply roller 34 is 9.85 degrees. However, the angle The degree α is not limited to this.

[0024] The developing unit 4 also receives the driving force of a main body drive motor (not shown) separate from the driving source of the cleaning unit, thereby rotating and driving the developing roller 25 and the toner supply roller 34 in response to the image forming operation. The driving force is input via a coupling, as with the cleaning unit 26, and will be described in detail later. The driving force input method using a coupling is preferable from the standpoint of rotational stability compared to driving force input via gears.

[0025] The developing roller 25 is an elastic roller configured with a conductive elastic rubber layer having a predetermined volume resistance as an elastic layer provided around a metal core. The developing roller 25 is composed of a base layer and a surface layer. Silicone rubber is used for the base layer, and urethane rubber is used for the surface layer, with urethane bead particles dispersed in the urethane rubber of the surface layer to set the desired roughness. The developing roller 25 and the photosensitive drum 1 rotate so that their surfaces move in the same direction (from bottom to top in this embodiment) at the opposing portion (contact portion). In this embodiment, toner negatively charged by friction with respect to a predetermined DC bias applied to the developing roller 25 transfers only to the light potential portion due to the potential difference in the developing portion contacting the photosensitive drum 1, thereby visualizing the electrostatic latent image.

[0026] The developing blade 35 is disposed below the developing roller 25 and is in counter contact with the developing roller 25, and regulates the coating amount of the toner supplied by the toner supply roller 34 and imparts an electric charge. In this embodiment, the developing blade 35 is composed of a flexible plate-like member and a developing blade 35 support body that fixes the plate-like member. The plate-like member is made of SUS (stainless steel) processed into a leaf spring shape with a thickness of 80 μm, and the free movement of the plate-like member is The contact portion located at the developing roller 25 contacts the developing roller 25 with a required contact pressure. The toner supplied onto the developing roller 25 is frictionally charged by the rubbing between the developing blade 35 and the developing roller 25, and is simultaneously charged and the layer thickness is regulated. In this embodiment, a predetermined voltage is applied to the developing blade 35 from a blade bias power source (not shown) to stabilize the toner coat.

[0027] The charged toner adheres to the surface of the developing roller 25 due to the image force with the developing roller 25. If the adhesion force of this toner to the surface of the developing roller 25 exceeds the regulating force of the developing blade 35, the toner coat on the developing roller 25 becomes disturbed (so-called "regulation failure"). When regulation failure occurs, image defects such as toner adhering to the white background of the image or abnormal density occur.

[0028] Here, the developing blade 35 of this embodiment will be described in detail. In this embodiment, the developing blade 35 is composed of a supporting metal plate 35a (blade supporting portion) made of stainless steel and a flexible plate-like member 35b (blade portion) as shown in FIG. 6. The plate-like member is integrated with the supporting metal plate by YAG laser welding. FIG. 3 is a conceptual cross-sectional view in the short side direction at the tip of the free end of the developing blade 35 according to the present invention. The surface 811 in FIG. 3 is the surface that mainly comes into contact with the developing roller 25.

[0029] 3, in this embodiment, a part of the "tip edge portion 818" on the tip (free end) side of the plate-shaped member 35b that is to come into contact with the developing roller 25 is scraped off by polishing. The part that is scraped off is formed over the entire longitudinal area of ​​the plate-shaped member.

[0030] The developing blade 35 is provided at a free end of the plate-shaped member 35b in the short side direction, and has a contact portion for contacting the surface of the developing roller 25.

[0031] More specifically, the tip of the developing blade 35 in this embodiment is 1 mm long in the longitudinal direction before being polished. In a cross section perpendicular to the direction, a first surface 811 (first portion) which is a surface on the side that contacts the developing roller 25 and a third surface 813 (third portion) perpendicular to the first surface 811 intersect to form the "tip edge portion 818" described above. Then, by performing polishing, the tip edge portion 818 is scraped off, and a second surface 812 (second portion) which connects the first surface 811 and the third surface 813 is formed. In the state after polishing, the tip point on the free end side of the first surface 811 is designated as point A, and the tip point on the free end side of the second surface 812 is designated as point B. Also, a virtual line extending the first surface 811 in the free end direction is designated as L1. Also, a point where a virtual line L2 which is perpendicular to the virtual line L1 and passes through point B intersects with the virtual line L1 is designated as point C. In this case, the distance between points B and C is defined as h1, and the distance between points A and C is defined as d1. In this embodiment, h1=15 μm, d1 =40 μm.

[0032] Next, the contact state between the developing roller 25 and the developing blade 35 will be described in detail with reference to Fig. 4. Fig. 4 is a schematic diagram showing the contact state between the developing roller 25 and the developing blade 35 in a cross section perpendicular to the longitudinal direction.

[0033] Point E is the point where a perpendicular line drawn to the surface of developing roller 25 intersects with the surface of developing roller 25 relative to tip position B of second surface 812 in Figure 4(a). If the contact area between developing roller 25 and developing blade 35 is defined as nip N1, then point D is the contact point in nip N1 that is closest to the free end of developing blade 35. Point D exists on second surface 812. The area surrounded by developing roller 25 surface DE, developing blade surface BD, and virtual line L2 (the shaded area in Figure 4(a)) can be defined as the "take-in area J."

[0034] In this embodiment, when the developing roller 25 is assembled, the surface of the developing roller 25 does not come into contact with the tip position B of the second side, that is, at least a part of the second side does not come into contact with the developing roller 25. This creates a state in which the entirety of the "take-in area J" is not covered by the developing roller 25, and allows an appropriate amount of toner coat to be formed on the developing roller 25 after the developing blade 35 has passed. In other words, by ensuring the "take-in area J", the toner It can be said that the government is increasing the amount of toner coating and weakening regulations on toner.

[0035] Here, let L3 be an imaginary line whose distance from the surface of the developing roller 25 is the volume average particle diameter R of the toner, F be the intersection point of L3 and the second surface 812, G be the point where the imaginary line L3 and the imaginary line L2 intersect, and let the tangent line to the second surface 812 at point F be imaginary line L4, then let d2 be the distance between points F and G, and θ be the angle that the imaginary line L4 makes with a straight line DE. In this embodiment, the volume average particle diameter R of the toner is 7.0 μm, d2=20 μm, and θ2=20°. The volume of the toner The average particle size (volume-based median diameter) was measured using a Coulter Counter Multisizer 3 (registered trademark, manufactured by Beckman Coulter, Inc.).

[0036] Here, the method of polishing the developing blade 35 used in the present invention will be described. The plate-shaped member before being joined to the support member is fixed to the base by being sandwiched between the base and the pressing member. The tip of the plate-shaped member is in contact with the polishing film wrapped around a rubber roller under a load. In this embodiment, a wrapping film sheet with a grain size of #800 is used as the polishing film, and a load of 500 g is applied to the rubber roller.

[0037] The polishing film on the rubber roller is arranged in a fixed state, and as the base moves left and right in the longitudinal direction, the tip of the plate-like member is rubbed against the polishing film and finely scraped off.

[0038] The amount of removal of the plate-like member is proportional to the distance of rubbing with the polishing film, and the longer the rubbing distance, the greater the amount of removal, and the shorter the distance, the less the amount of removal. In other words, by controlling the amount of movement of the base, the amount of removal of the tip edge of the plate-like member can be changed. This is just one example, and the present invention is not limited to this example as long as the tip of the developing blade can be processed into a desired shape.

[0039] The toner supply roller 34 is in contact with the developing roller 25 at a nip portion N2, and as shown in the figure, the toner supply roller 34 receives a driving force from a driving motor (not shown) and is rotated in response to an image forming operation. This will be described in detail with reference to FIG.

[0040] The driving force from the main body drive motor is transmitted to the coupling 201 (driving force receiving portion), and the driving force is transmitted to the toner supply roller 34 via the intermediate body 202 and the driving force transmission member 203 (the intermediate body 202 and the driving force transmission member 203 are the first driving force transmission portion). The driving force of the toner supply roller 34 is transmitted to the developing roller 25 by the gears (204a to 204c) provided between the toner supply roller 34 and the developing roller 25, and the developing roller 25 rotates (the gear 204c is the second driving force transmission portion, and the gear 204a is the third driving force transmission portion). In detail, the gear 204c fixed to the toner supply roller 34 rotates, and the driving force is transmitted to the idler gear 204b, and the idler gear 204b rotates. The idler gear 204b rotates, and the driving force is transmitted to the gear 204a fixed to the developing roller 25, and the developing roller 25 rotates together with the gear 204a.

[0041] In this embodiment, the driving force from the apparatus main body 100a to the developing unit 4 is input from the longitudinal axis of the toner supply roller 34, but if the driving force from the apparatus main body 100a to the developing unit 4 is configured to be input from the longitudinal axis of the developing roller 25, the driving input positions to the cleaning unit 26 and the developing unit 4 will be close to each other due to the relationship that the photosensitive drum 1 and the developing roller 25 are in contact with each other for development. With such an input portion arrangement, it is difficult to simply configure the driving input portion of the apparatus main body 10, and it is not preferable when configuring a more stable driving input portion at low cost.

[0042] In contrast to this, in this embodiment, the driving force to the developing unit 4 is input from the longitudinal axis of the toner supply roller 34, so that the distance between the input position to the cleaning unit 26 and the driving force input position to the developing unit 4 can be increased, which is more preferable when configuring the driving force input portion of the device main body 100a.

[0043] On the other hand, in the configuration of this embodiment in which the driving force from the apparatus main body 100a is transmitted to the developing roller 25 via the toner supply roller 34, multiple gears must be passed through in order to drive the developing roller 25, and therefore the rotation stability of the developing roller 25 is inferior to that of the configuration in which the driving force is transmitted to the developing roller 25. As a result, the regulating force of the developing blade 35 may become unstable, and this configuration is disadvantageous in terms of regulating failure.

[0044] In addition, the toner supply roller 34 and the developing roller 25 rotate in opposite directions with a peripheral speed difference at the nip portion N2. This operation recovers the remaining toner on the developing roller 25 while supplying toner to the developing roller 25.

[0045] In this embodiment, when the peripheral speed of the toner supply roller 34 at the nip portion N2 is Vrs and the peripheral speed of the developing roller 25 is Vd, they are set so that Vrs / Vd>1, i.e., Vrs / Vd=1.25. That is, when the radius of the toner supply roller 34 is Rrs [mm], the rotational angular velocity of the toner supply roller 34 is ωrs [rad / sec], the radius of the developing roller 25 is Rd [mm], the rotational angular velocity of the developing roller 25 is ωd [rad / sec], and the rotational angular velocity ratio λ (=ωrs / ωd) between the toner supply roller 34 and the developing roller 25 is λ×Rrs / Rd>1.0. In this embodiment, the radius of the toner supply roller is 3.3 mm and the radius of the developing roller is 3.0 mm, so that λ≈1.14. By making Vrs / Vd>1, the remaining toner on the developing roller 25 can be collected and the developing roller This allows efficient supply of toner to the roller 25. On the other hand, from the viewpoint of poor regulation, this is a disadvantageous configuration since the amount of toner supplied increases.

[0046] At this time, by adjusting the potential difference between the toner supply roller 34 and the developing roller 25, the amount of remaining toner collected on the developing roller 25 and the amount of toner supplied to the developing roller 25 can be adjusted.

[0047] Further, the toner supply roller 34 and the developing roller 25 are in contact with each other with a predetermined intrusion amount, that is, the indentation amount ΔE by which the toner supply roller 34 is made in a concave shape by the developing roller 25 .

[0048] The toner supply roller 34 includes a conductive support and a foam layer supported by the conductive support. Specifically, the conductive support is a core metal electrode with an outer diameter of φ5 (mm), and a foamed urethane layer is provided around the core metal electrode as a foam layer composed of open cells (open cells) in which air bubbles are connected to each other, and the roller rotates in the direction of C in the figure. By making the urethane surface layer open cells in this way, a large amount of toner can enter the inside of the toner supply roller 34. The resistance of the toner supply roller 34 in this embodiment is 1×10^9 (Ω).

[0049] In this embodiment, the amount of penetration of the toner supply roller 34 into the developing roller 25, i.e., the amount of depression ΔE of the toner supply roller 34 made concave by the developing roller 25, was set to 1.0 mm. Here, a method for measuring the resistance of the toner supply roller 34 will be described. The toner supply roller 34 is brought into contact with an aluminum sleeve having a diameter of 30 mm so that the amount of penetration, which will be described later, is 1.5 mm. By rotating this aluminum sleeve, the toner supply roller 34 is rotated at 30 rpm relative to the aluminum sleeve.

[0050] Next, a DC voltage of -50V is applied to the developing roller 25. At this time, a resistor of 10 kΩ is provided on the earth side, and the current is calculated by measuring the voltage across the resistor, and the resistance of the toner supply roller 34 is calculated. In this embodiment, the surface cell diameter of the toner supply roller 34 is set to 50 μm to 1000 μm.

[0051] Here, the cell diameter refers to the average diameter of foam cells in an arbitrary cross section, and the area of ​​the largest foam cell is measured from an enlarged image of the arbitrary cross section, and the maximum cell diameter is obtained by converting this area into a diameter equivalent to a perfect circle. After removing foam cells that are 1 / 2 or less of this maximum cell diameter as noise, the remaining individual cell areas are similarly converted to obtain the average cell diameter.

[0052] The toner supplied from the toner supply roller 34 to the surface of the developing roller 25 is frictionally charged by the rubbing between the developing blade 35 and the developing roller 25, and the layer thickness is regulated while the toner is given an electric charge. The toner is then transported to the contact portion (developing portion) between the photosensitive drum 1 and the developing roller 25, and transferred to the light potential portion. Residual toner remaining on the surface of the developing roller 25 returns to the developer container, is collected from the surface of the developing roller 25 by the toner supply roller 34, and is stored inside the toner supply roller 34.

[0053] Here, the flow of toner in the developing chamber 31b will be described with reference to Fig. 6. In this embodiment, Fig. 6 is an enlarged schematic cross-sectional view of the inside of the developing chamber 31b, and shows the movement of toner transported to the toner supply roller 34 by the toner transport member 36 shown in Fig. 2.

[0054] A part of the toner G transported to the upper part of the toner supply roller 34 by the toner transport member 36 is sucked into the inside of the toner supply roller 34 due to the restoration of the toner supply roller 34 on the downstream side of the rotation of the toner supply roller 34 at the nip portion N2 (F1), and is stored inside the toner supply roller 34 together with the remaining toner that was collected from the surface of the developing roller 25 and stored inside the toner supply roller 34. Then, due to the rotation of the toner supply roller 34 in the C direction, the toner in the nip portion N2 is sucked into the inside of the toner supply roller 34 due to the restoration of the toner supply roller 34 (F2). The toner is conveyed downstream of the rotation of the toner supply roller 34. On the downstream side of the rotation of the toner supply roller 34, the toner supply roller 34 comes into contact with the developing roller 25, causing the toner supply roller 34 to deform, causing the toner stored inside to be expelled (F2).

[0055] The toner discharged from the toner supply roller 34 that does not reach the surface of the developing roller 25 is gradually transported by the propulsion force toward the developing opening (opening) due to the ejection force from the toner supply roller 34, and passes through the developing opening and is returned to the toner storage chamber 31a (F3).

[0056] In this way, the toner circulates smoothly between the developing chamber 31b and the toner storage chamber 31a, thereby suppressing toner deterioration, and even when images with low print coverage are output continuously, the occurrence of toner aggregation is suppressed, making it possible to stably output high-quality images.

[0057] Here, if the flow (F3) of toner returning to the toner storage chamber 31a becomes insufficient, the toner is pressed down and aggregates in the area below the toner supply roller 34 and the developing roller 25. Then, the toner enters the nip portion N2 between the toner supply roller 34 and the developing roller 25, and the contact of the toner supply roller 34 with the developing roller 25 becomes insufficient. An area occurs where the remaining toner on the developing roller 25 cannot be sufficiently collected by the toner supply roller 34, and a specific toner is carried around by the developing roller 25 and passes through the contact portion between the developing blade 35 and the developing roller 25 more than necessary, resulting in the generation of toner that is excessively charged. As a result, the adhesion force of the toner exceeds the regulating force of the developing blade 35, and a regulating failure may occur.

[0058] This phenomenon is likely to occur, for example, when images with a low printing rate are continuously output in a low-temperature, low-humidity environment. This is because the residual toner collected from the developing roller 25 by the toner supply roller 34 accumulates in the developing chamber 31b. The residual toner collected from the developing roller 25 is charged, so the toner particles tend to electrostatically clump together. This reduces the fluidity of the toner in the developing chamber 31b, making the flow of toner (F3) returning to the toner storage chamber 31a insufficient, and creating a state in which toner clumping is likely to occur in the areas below the toner supply roller 34 and the developing roller 25.

[0059] In response to this, there is a method of arranging a toner transport member below the toner supply roller 34 in the developing chamber 31b, thereby creating a toner flow (F3) that returns to the toner storage chamber 31a. However, when a toner transport member is provided in the developing chamber 31b, the toner deteriorates due to friction between the toner and the toner transport member in the developing chamber 31b, and toner fusion to the developing roller 25 was observed when images with a low printing rate were continuously produced. In addition, since it is necessary to provide a toner transport member as an additional member in addition to the toner supply roller 34 in the developing chamber 31b, the device configuration becomes complicated. Therefore, in this embodiment, no members that are driven by motor drive are provided in the developing chamber 31b other than the developing roller 25 and the toner supply roller 34.

[0060] In addition, in a configuration in which only the developing roller 25 and the toner supply roller 34 are arranged in the developing chamber 31b, in order to efficiently use the toner in the developing chamber 31b, the inner wall of the developing chamber 31b is set as follows relative to the toner supply roller 34. This will be specifically explained with reference to FIG.

[0061] 7, R1 and R2 indicate tangents (vertical lines) to the outer peripheral surface of the toner supply roller 34 that extends in the vertical direction. In addition, horizontal line H2 indicates a horizontal line that passes through the support end of the developing blade 35. In the region between R1 and R2 of the inner wall of the developing chamber 31b, at least a portion is arranged to be vertically above the horizontal line H2 (region 138 in the figure). This makes it possible to further reduce the amount of toner remaining in the developing chamber 31b that is not used for printing, and toner in the developing chamber 31b can be used efficiently.

[0062] As shown in FIG. 2, a blowout prevention sheet 20 is disposed as a developer contact sheet for preventing toner from leaking from the developing frame 31 in contact with the developing roller 25.

[0063] Further, the toner storage chamber 31a of the developing frame 31 is provided with a toner transport member 36 for stirring the stored toner and transporting the toner to the toner supply roller 34. As shown in Fig. 2, the toner transport member 36 is composed of a stirring shaft 36a that can be rotated by a driving force from the apparatus main body 100a, and a sheet member 36b that is attached to the stirring shaft 36a and rotates together with the stirring shaft 36a.

[0064] Next, the toner transport of the developing unit will be described. The toner storage chamber 31a is provided with a deformation portion 31a1 that contacts the sheet member 36b below the opening 31c (communication port). The sheet member 36b contacts the deformation portion 31a1 as it rotates. This causes the sheet member 36b to receive force from the deformation portion 31a1. As a result, the sheet member 36b deforms against the elastic force of the sheet member 36b. In addition, the sheet member 36b rotates in contact with the deformation portion 31a1, so that the toner is transported while being carried on the surface downstream of the rotation. In this embodiment, the deformation portion 31a1 refers to the portion of the inner wall of the toner storage chamber up to the portion where the sheet member 36b leaves as shown in FIG. 2.

[0065] The toner storage chamber 31a is provided with a restoring portion 31a2 downstream of the deformation portion 31a1 and upstream of the opening 31c in the rotation of the sheet member 36b. The restoring portion 31a2 is a portion for releasing the contact between the sheet member 36b and the inner wall of the toner storage chamber 31a. In this embodiment, the restoring portion 31a2 is disposed above a horizontal plane including the rotation axis of the stirring member.

[0066] Therefore, after the tip of the free end side of the sheet member 36b passes through the deformation portion 31a1 as the sheet member 36b rotates, the contact with the inner wall of the sheet member 36b is released at the restoration portion 31a2. Then, the sheet member 36b is released from the state in which it was deformed by the deformation portion 31a1 and is restored to its natural state (original shape) by its own elastic restoring force. Due to the shape change of the sheet member 36b in the restoration direction, the toner carried and transported on the sheet member 36b flies against gravity toward the opening 31c. This opening 31c is located downstream of the restoration portion 31a2 in the rotation direction of the sheet member 36b. A part of the toner that flies toward the opening 31c is transported into the developing chamber 31b. On the other hand, the toner that does not reach the developing chamber 31b falls into the toner storage chamber 31a and remains at the bottom of the toner storage chamber 31a, and returns to its original state. By repeating this cycle, the toner is stirred and transported.

[0067] The configuration in which the deformation portion 31a1 and the restoration portion 31a2 are provided is to improve the efficiency of conveying the toner to the developing chamber 31b. However, since the toner flow (F3) returning to the toner storage chamber is easily hindered, the toner flow is likely to be impeded, and therefore the toner flow is likely to be impeded.

[0068] In this embodiment, the length of the sheet member 36b in the direction of the rotation radius of the rotation axis in the natural state is set to be longer than the distance from the rotation axis to the lower end of the developing opening in the same direction. This configuration is advantageous for increasing the efficiency of transporting toner to the developing chamber 31b, but it is likely to obstruct the flow (F3) of toner returning to the toner storage chamber 31a, and is therefore likely to cause regulation failure.

[0069] In this embodiment, in order to transport a sufficient amount of toner from the toner storage chamber 31a to the developing chamber 31b, two sets of sheet members 36b are attached at different positions on the agitating shaft 36a. This configuration is advantageous for increasing the efficiency of transporting toner to the developing chamber 31b, but it is likely to obstruct the flow (F3) of toner returning to the toner storage chamber 31a. Therefore, this configuration is prone to regulation failure.

[0070] [toner] Next, the toner of the present invention will be described. Hereinafter, the description of "XX or more and YY or less" or "XX to YY" representing a numerical range means a numerical range including the lower and upper limits which are the endpoints, unless otherwise specified. When a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined. "(Meth)acrylic" means "acrylic" and / or "methacrylic".

[0071] The toner in this embodiment is a toner containing toner particles containing a binder resin, and hydrotalcite particles used as a microcarrier to enhance the negative charging characteristics of the toner particles. In addition, the hydrotalcite particles contain fluorine. Since the hydrotalcite particles are highly charged to the positive polarity, they have a strong positive polarity. By making the hydrotalcite particles contain fluorine, the charge amount can be adjusted so that they do not have a strong positive polarity. By making the hydrotalcite particles contain fluorine, it is possible to prevent the hydrotalcite particles from being charged to a strong positive polarity, and therefore it is possible to prevent the toner from becoming a strong negative polarity. In other words, it is possible to make the charge distribution of the toner a sharp distribution of negative polarity. As an example, a toner containing hydrotalcite that does not contain fluorine and a toner containing hydrotalcite that contains fluorine were prepared in the same toner particles (toner 1 described later), and the charge amount distribution of the toner was measured. Using the image forming apparatus 100 and the process cartridge 70 of this embodiment, the toner on the developing roller 25 was sampled after forming one plain (solid white) image. The charge amount of the sampled toner was measured. The charge amount was measured using a Hosokawa Micron E-SpartAnalyzer. The percentage of strongly negative toner particles with a charge amount per unit weight Q / M of -25 [μC / g] or more (evaluated in absolute value) was compared. It was confirmed that the percentage of strongly negative toner particles was reduced by approximately 23% for toner with fluorine-containing hydrotalcite added, compared to toner with non-fluorine-containing hydrotalcite added.

[0072] By using a toner having fluorine-containing hydrotalcite added thereto and the developing blade 35 having the aforementioned "capture area J" at its leading edge, it is possible to suppress the regulation failure. The mechanism behind this is explained below.

[0073] 4(a), in the developing blade 35 provided with the "capture area J" at the leading edge, the toner particles rub against each other in the "capture area J," thereby transferring the charge held by the toner. This makes it possible to make the charge distribution of the toner passing through the regulating portion of the developing blade 35 a sharp distribution.

[0074] On the other hand, when using a developing blade 35 that does not have an "acquisition area J" as shown in Figure 4(b), in order to obtain a toner coat amount necessary to obtain the desired image density, it is necessary to set the contact position of the developing roller 25 with the developing blade 35 on the fixed end side.

[0075] Figure 8 illustrates the movement of toner regulated by the developing blade 35 when a developing blade 35 having a "capture area J" at the leading edge is used, and when a developing blade 35 having no "capture area J" at the leading edge is used.

[0076] FIG. 8(a) is a diagram showing the case where a developing blade 35 with a "capture area J" is provided at the leading edge portion is used. The white circles in the figure represent toner, and the movement of the toner regulated by the developing blade 35 is indicated by arrow K1. A portion of the toner that has invaded close to the point of contact D with the developing blade 35 due to the rotation of the developing roller 25 in the direction of arrow D1 is detached from the surface of the developing roller 25 by the regulating force of the developing blade 35. This regulated toner is absorbed by the toner from behind. Because the movement in the direction where the powder pressure is weaker becomes stronger, a movement is generated that returns to inside the developing chamber 31b along the second surface 812 of the leading edge portion. As a result, good toner circulation can be created in the "take-in area J" of the leading edge portion, and in this circulation, the charge held by the toner can be transferred by friction between the toner particles.

[0077] It is believed that the above-mentioned toner circulation occurs because, in the "take-in area J" of the leading edge of the developing blade 35, there is at least a point F on the developing blade 35 that is farther away from the developing roller 25 than the volume average particle diameter R of the toner, and the width d2 of the take-in area on the free end side of point F is greater than the volume average particle diameter R of the toner, i.e., it is possible for one toner particle to exist in the "take-in area." The volume average particle diameter of the toner used in this embodiment is about 7.0 μm, and the leading edge shape of the developing blade is polished so that the above-mentioned point F exists and d2 is greater than the volume average particle diameter R of the toner.

[0078] Furthermore, it is preferable to set the angle θ between the developing blade 35 and the developing roller 25 at point F to 45° or less, so that the direction of the arrow K1 is more opposite to the direction of movement of the developing roller 25, which causes the toner particles to rub against each other more frequently in the "take-in area J", making it easier to achieve the effect of transferring the charge held by the toner. More preferably, setting θ to 25° or less makes it easier to achieve the above effect.

[0079] On the other hand, FIG. 8(b) shows a case where a developing blade 35 without a "capture area J" at the leading edge is used. When such a developing blade 35 is used, in order to obtain a toner coat amount for obtaining a desired image density, it is necessary to set the contact point D of the developing roller 25 with respect to the developing blade 35 on the fixed end side compared to the developing blade 35 in FIG. 8(a). By setting it in this way, a sufficient amount of toner can be taken into the regulating portion. At this time, the toner regulated by the regulating force of the developing blade 35 is unlikely to move back into the developing chamber 31b due to the powder pressure of the toner transported from the rear by the rotation of the developing roller 25. Therefore, as a result, a force is generated in the direction K2 that pushes up the developing blade 35 by the regulated toner. Then, the contact pressure of the developing blade 35 against the developing roller 25 is reduced, and the regulating force by the developing blade 35 is weakened. As a result, the adhesion force of the toner to the developing roller 25 exceeds the regulating force of the developing blade 35, and there is a possibility that a regulating failure occurs.

[0080] Furthermore, when a toner containing no fluorine-containing hydrotalcite is used, the amount of toner with a strong negative polarity increases compared to a toner containing fluorine-containing hydrotalcite, as described above. In this case, when a developing blade 35 that does not have an "intake area J" at its leading edge is used, the regulating force of the developing blade 35 weakens, and regulating failures are likely to occur, just like when a toner containing fluorine-containing hydrotalcite is used.

[0081] Even if the developing blade 35 having the "capture area J" at the leading edge is used and the toner particles are rubbed against each other in the "capture area J," the proportion of toner particles with a strong negative polarity increases. As a result, toner particles may adhere to the developing roller 25 with a force exceeding the regulating force of the developing blade 35, resulting in poor regulation.

[0082] In addition, when the ratio of the number of toner particles with a strong negative polarity increases, electrostatic cohesion of the toner particles is likely to occur. This may cause the toner flow (F3) into the toner storage chamber 31a to deteriorate and become insufficient, which may result in a regulation failure.

[0083] To summarize the above, by using toner with fluorine-containing hydrotalcite added to the outside and the developing blade 35 with the "capture area J" at the leading edge, the toner can be prevented from being strongly charged to the negative polarity due to the effect of promoting the friction between the toner particles by the "capture area J". As a result, the toner with an adhesion force to the developing roller 25 that exceeds the regulating force of the developing blade 35 is prevented from being strongly charged to the negative polarity. At the same time, electrostatic aggregation of toner particles can also be suppressed, and by maintaining a sufficient flow (F3) of toner into the toner storage chamber 31a, the occurrence of toner aggregation in the area below the toner supply roller 34 and the developing roller 25 can be suppressed.

[0084] Due to these two effects, by using toner with fluorine-containing hydrotalcite added to its outside and the developing blade 35 having the "capture area J" at its leading edge, it is possible to suppress the occurrence of regulation failure.

[0085] In this embodiment, in order to facilitate the transfer of charge of the toner particles due to friction between the toner particles in the "capture area J," the capture angle θ is set to be in the range of 0°<θ<25°. This makes it possible to make the charge distribution of the toner passing through the regulating portion of the developing blade 35 a sharp distribution.

[0086] The hydrotalcite particles used in the toner in this embodiment will be described in detail. The hydrotalcite particles contain fluorine. Here, the presence or absence of fluorine in the hydrotalcite particles can be confirmed by STEM-EDS mapping analysis of the toner. The analysis conditions and the like are adopted as described later. In addition, in the line analysis in the STEM-EDS mapping analysis of the toner, the hydrotalcite particles have fluorine present inside the hydrotalcite particles. Specifically, this means that EDS line analysis is performed in the normal direction to the outer periphery of the hydrotalcite particles containing fluorine, and fluorine present inside the particles is detected. The detection of fluorine inside the hydrotalcite particles by the above analysis indicates that fluorine is intercalated between the layers of the hydrotalcite particles. The presence of fluorine inside the hydrotalcite particles allows the hydrotalcite particles to maintain a moderate amount of positive charge without being excessively charged positively. The reason why the hydrotalcite particles can maintain an appropriate amount of positive charge is that the highly negative fluorine present inside the hydrotalcite particles can neutralize the positive charge on the surface of the hydrotalcite particles by being absorbed into the inside of the particles, i.e., it is presumed that this is because excessive positive charging of the particle surface can be suppressed.

[0087] Incidentally, the introduction of fluorine into the inside of the hydrotalcite particles is preferably carried out by introducing fluoride ions between layers (intercalation) by anion exchange.

[0088] The ratio F / Al (element ratio) of the atomic concentration of fluorine to aluminum in the hydrotalcite particles, obtained from main component mapping of the hydrotalcite particles by STEM-EDS mapping analysis of the toner, is preferably 0.01 to 0.65, and more preferably 0.02 to 0.60. Specifically, by making F / Al 0.01 or more, the surface charge distribution of the hydrotalcite particles can be made uniform, and the charge stability of the toner can be improved, resulting in a toner that is sharply negatively charged. In addition, by making F / Al 0.65 or less, the surface charge of the hydrotalcite particles is prevented from being excessively neutralized, the time stability of the positive charge is improved, and the charge stability of the toner is improved. As a result, the charge of the toner is prevented from becoming strongly negative, and a toner with a sharp charge distribution of negative polarity can be obtained.

[0089] The fluorine atom concentration in the hydrotalcite particles is not particularly limited, but is preferably 0.01 atomic % to 5.00 atomic %, more preferably 0.04 atomic % to 3.00 atomic %, and even more preferably 0.09 atomic % to 2.00 atomic %. Within this range, the hydrotalcite particles have an appropriate positivity and the microcarrier properties are in an appropriate range.

[0090] The hydrotalcite particles may be those represented by the following composition formula (1): In the composition formula (1), M and A are represented in an ionic state. M 2+ y M 3+ x (OH) 2 A n- (x / n) mH 2 O formula (1) Said M 2+ , and M 3+ represent divalent and trivalent metal cations, respectively.

[0091] The hydrotalcite particles may be a solid solution containing a plurality of different elements. They may also contain a trace amount of a monovalent metal. However, it is preferably that 0 < x ≦ 0.5, y = 1 - x, and m ≧ 0. M 2+ is preferably a divalent cation of at least one metal selected from the group consisting of Mg, Zn, Ca, Ba, Ni, Sr, Cu, and Fe. M 3+ is preferably a trivalent cation of at least one metal selected from the group consisting of Al, B, Ga, Fe, Co, and In. A n- is an n-valent anion and contains at least F - . A n- contains, in addition to F - , CO 3 2- , OH - , Cl - , I - , Br - , SO 4 2- , HCO 3 - , CH 3 COO - , and NO 3 - etc., and may contain a plurality of different anions.

[0092] As the metal that becomes the divalent cation, Mg (magnesium) is preferable, and as the metal that becomes the trivalent cation, Al (aluminum) is preferable. The hydrotalcite particles preferably contain aluminum as the trivalent cation and magnesium as the divalent cation. As a specific composition formula, Mg 2+ 8.6 Al 3+ 4 (OH) 25.2 F - 2 CO 3 2- ·mH 2 O, Mg 2+ 12 Al3+ 4 (OH) 32 F - 2 CO 3 2- ·mH 2 Examples include O and the like.

[0093] When the hydrotalcite particles contain aluminum which becomes a trivalent cation and magnesium which becomes a divalent cation, the value (Mg / Al) of the ratio of the atomic concentration (atomic %) of magnesium to the atomic concentration (atomic %) of aluminum is preferably 1.50 to 4.00.

[0094] Also, the hydrotalcite particles preferably have water in their molecules, and in formula (1), it is more preferable that 0.1 < m < 0.6.

[0095] The number average particle diameter H3 of the primary particles of the hydrotalcite particles is preferably 40 nm to 1100 nm, and more preferably 60 nm to 1000 nm. When the number average particle diameter of the hydrotalcite particles is within the above range, the charge rising property of the toner becomes good, and the charge distribution of the toner is likely to be sharpened.

[0096] The above particle diameter can be measured using known means such as a scanning electron microscope. Also, the above particle diameter can be controlled by controlling the conditions of the reaction process, grinding process, centrifugation process, classification process, and sieving process in the manufacturing process of the hydrotalcite particles.

[0097] The hydrotalcite particles may be hydrophobically treated with a surface treatment agent. As the surface treatment agent, higher fatty acids, coupling agents, esters, oils such as silicone oil can be used. Among them, higher fatty acids are preferably used, and specifically, stearic acid, oleic acid, and lauric acid are exemplified.

[0098] The content of the hydrotalcite particles in the toner is not particularly limited. It is preferably 0.01 to 3.00 parts by mass, more preferably 0.05 to 0.50 parts by mass, and further preferably 0.05 to 0.30 parts by mass, based on 100 parts by mass of the toner particles. The content of hydrotalcite particles can be quantified using fluorescent X-ray analysis and a calibration curve prepared from a standard sample.

[0099] The adhesion rate of the hydrotalcite particles to the toner particles is preferably 10% to 95%, more preferably 40% to 95%, and even more preferably 50% to 70%. When the adhesion rate is within the above range, the above effects are easily obtained. The adhesion rate can be controlled by changing the external addition conditions using a known external addition method.

[0100] The area ratio of the hydrotalcite particles to the toner particles in the EDS measurement field of view measured by STEM-EDS mapping analysis of the toner is preferably 0.07% to 0.54%, more preferably 0.25% to 0.50%, and even more preferably 0.35% to 0.45%. When it is in the above range, the above effect is easily obtained. The above area ratio can be controlled by changing the input amount of the hydrotalcite particles.

[0101] <Method of manufacturing toner particles> The method for producing the toner particles is not particularly limited and may be a known method, such as a kneading and grinding method or a wet production method. From the viewpoints of uniforming the particle size, shape controllability, and ease of obtaining toner particles with a core-shell structure, the wet production method is preferred. Examples of the wet production method include a suspension polymerization method, a dissolution suspension method, an emulsion polymerization aggregation method, and an emulsion aggregation method (the difference between emulsion polymerization aggregation and emulsion aggregation), and the emulsion aggregation method is more preferred from the viewpoint of dispersing the polyvalent metal element on the surface of the toner particles and inside the toner particles.

[0102] In the emulsion aggregation method, first, a dispersion of each material such as binder resin particles and colorant is prepared. The obtained dispersion of each material is dispersed and mixed by adding a dispersion stabilizer as necessary. Then, an aggregating agent is added to aggregate the particles to the desired toner particle size, and then or simultaneously with the aggregation, the resin particles are fused together. If necessary, the shape is controlled by heat to form toner particles.

[0103] Here, the binder resin particles can be composite particles formed of a plurality of layers, each of which is made of two or more layers of resins with different compositions. For example, they can be manufactured by emulsion polymerization, mini-emulsion polymerization, phase inversion emulsification, or a combination of several manufacturing methods. When an internal additive is contained in the toner particles, the internal additive may be contained in the resin particles, or a dispersion liquid of internal additive particles consisting of only the internal additive may be separately prepared, and the internal additive particles may be aggregated together with the resin particles when the resin particles are aggregated. In addition, resin particles with different compositions can be added at different times during aggregation and aggregated to produce toner particles with layer configurations with different compositions.

[0104] As the dispersion stabilizer, a known surfactant can be used. As the flocculant, in addition to a surfactant having a polarity opposite to that of the surfactant used in the dispersion stabilizer described above, an inorganic salt, or an inorganic metal salt having a valence of 2 or more can be suitably used. In particular, an inorganic metal salt is preferred because it is easy to control the flocculation property and the toner charge property by ionizing a polyvalent metal element in an aqueous medium. Specific examples of preferred inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, iron chloride, aluminum chloride, and aluminum sulfate, as well as inorganic metal salt polymers such as polyiron chloride, polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Among these, aluminum salts and their polymers are particularly preferred. In general, in order to obtain a sharper particle size distribution, the valence of the inorganic metal salt is preferably divalent rather than monovalent, and more preferably trivalent or more than divalent, and even if the valence is the same, inorganic metal salt polymers are more suitable.

[0105] From the viewpoint of high definition and high resolution of images, the volume-based median diameter of the toner particles is preferably 3.0 μm to 10.0 μm.

[0106] <Toner manufacturing method> The toner contains hydrotalcite particles as an external additive. If necessary, other external additives may be added. In this case, the content of the external additives such as inorganic and organic fine particles including hydrotalcite particles is preferably 0.50 parts by mass to 5.00 parts by mass in total with respect to 100 parts by mass of the toner particles.

[0107] The mixer for adding the external additive to the toner particles is not particularly limited, and any known mixer can be used, regardless of whether it is a dry or wet type. Examples include FM Mixer (manufactured by Nippon Coke & Engineering Co., Ltd.), Mitsui Henschel Mixer (Mitsui Miike Chemical Engineering Co., Ltd.), Super Mixer (manufactured by Kawata Corporation), Nobilta (manufactured by Hosokawa Micron Corporation), and Hybridizer (manufactured by Nara Machinery Co., Ltd.). To control the coating state of the external additive, the toner can be prepared by adjusting the rotation speed, processing time, and water temperature and amount of water in the jacket of the external addition device.

[0108] The methods for measuring the physical properties of the toner and each material will be described below. <Method for identifying hydrotalcite particles> Hydrotalcite particles can be identified by a combination of shape observation using a scanning electron microscope (SEM) and elemental analysis using energy dispersive X-ray analysis (EDS).

[0109] Using a scanning electron microscope "S-4800" (product name; manufactured by Hitachi), the toner is observed at a maximum magnification of 50,000 times. The focus is adjusted to the surface of the toner particles, and the external additive to be identified is observed. An EDS analysis is performed on the external additive to be identified, and the hydrotalcite particles can be identified from the type of element peak.

[0110] When element peaks observed include an element peak of at least one metal selected from the group consisting of Mg, Zn, Ca, Ba, Ni, Sr, Cu, and Fe, which are metals that can constitute hydrotalcite particles, and an element peak of at least one metal selected from the group consisting of Al, B, Ga, Fe, Co, and In, the presence of hydrotalcite particles containing the two types of metals can be inferred.

[0111] A specimen of the hydrotalcite particles estimated by EDS analysis is prepared separately, and its shape is observed by SEM and analyzed by EDS. The analysis results of the specimen are compared to the analysis results of the particles to be identified to see if they match, and it is determined whether or not they are hydrotalcite particles.

[0112] <Method for measuring the ratio of each element in hydrotalcite particles> The ratio of each element in hydrotalcite particles is measured by EDS mapping measurement of the toner using a scanning transmission electron microscope (STEM). In EDS mapping measurement, spectrum data is obtained for each pixel in the analysis area. By using a silicon drift detector with a large detection element area, EDS mapping can be measured with high sensitivity.

[0113] By performing statistical analysis on the spectral data for each pixel obtained by EDS mapping measurement, it is possible to obtain a principal component mapping that extracts pixels with similar spectra, making it possible to map specific components.

[0114] The observation sample is prepared according to the following procedure. 0.5 g of the toner is weighed out, and placed in a cylindrical mold with a diameter of 8 mm and left to stand for 2 minutes under a load of 40 kN using a Newton press to prepare a cylindrical toner pellet with a diameter of 8 mm and a thickness of approximately 1 mm. A 200 nm-thick slice is prepared from the toner pellet using an ultramicrotome (Leica, FC7).

[0115] The STEM-EDS analysis is carried out using the following equipment and conditions. Scanning transmission electron microscope: JEM-2800 manufactured by JEOL Ltd. EDS detector: JED-2300T Dry SD100GV detector (detector area: 100 mm 2 ) EDS analyzer: NORAN, manufactured by Thermo Fisher Scientific System 7 [Conditions for STEM-EDS] STEM accelerating voltage: 200kV ·Magnification: 20,000x Probe size 1nm STEM image size: 1024 x 1024 pixels (EDS element mapping images are acquired at the same position.) EDS mapping size: 256 x 256 pixels, Dwell Time: 30 μs, Integration count: 100 frames

[0116] The ratio of each element in the hydrotalcite particles is calculated based on the multivariate analysis as follows.

[0117] The EDS mapping is obtained by the STEM-EDS analysis device. Next, the collected spectral mapping data is subjected to multivariate analysis using the COMPASS (PCA) mode in the measurement command of the NORAN System 7 described above, and a principal component map image is extracted.

[0118] At that time, the setting values ​​were as follows: Kernel size: 3×3 Quantitative map setting: High (slow) Filter Fit Type: High Precision (Slow)

[0119] At the same time, this operation calculates the area ratio of each extracted principal component in the EDS measurement field of view. Quantitative analysis is performed on the EDS spectrum of each obtained principal component mapping by the Cliff-Lorimer method.

[0120] The toner particle portion and the hydrotalcite particles are distinguished based on the quantitative analysis results of the obtained STEM-EDS main component mapping. The particles can be identified as hydrotalcite particles based on the particle size, shape, content of polyvalent metals such as aluminum and magnesium, and the amount ratio thereof.

[0121] <Analysis method for fluorine and aluminum in hydrotalcite particles> Based on the mapping data obtained by the above-mentioned method using STEM-EDS mapping analysis, the fluorine and aluminum in the hydrotalcite particles are analyzed. Specifically, EDS line analysis is performed in the normal direction to the outer periphery of the hydrotalcite particle, and the fluorine and aluminum present inside the particle are analyzed.

[0122] A schematic diagram of the line analysis is shown in FIG. 9(a). In a toner particle 91 and a hydrotalcite particle 93 adjacent to a toner particle 92, Then, line analysis is performed in the normal direction, i.e., in the direction of 95. Note that 94 indicates the boundary of the toner particle.

[0123] The area in the acquired STEM image where hydrotalcite particles exist is selected using the rectangular selection tool, and line analysis is performed under the following conditions. Line analysis conditions STEM magnification: 800,000x Line length: 200nm Line width: 30 nm Number of line divisions: 100 points (intensity measurement every 2 nm)

[0124] The criteria for determining that the element is contained inside the hydrotalcite particles are as follows: When the element peak intensity of fluorine or aluminum is 1.5 times or more the background intensity in the EDS spectrum of the hydrotalcite particles. When the element peak intensity of fluorine or aluminum at both ends of the hydrotalcite particle (points a and b in Figure 9(a)) in the line analysis does not exceed 3.0 times the peak intensity at point c. When all of the above conditions are met, the element is determined to be contained inside the hydrotalcite particles. Note that point c is the midpoint of line segment ab (i.e., the midpoint of the above-mentioned both ends).

[0125] Examples of the X-ray intensities of fluorine and aluminum obtained by line analysis are shown in Figures 9(b) and 9(c). When the hydrotalcite particles contain fluorine and aluminum inside, the graph of the X-ray intensity normalized by the peak intensity shows a shape as shown in Figure 9(b). When the hydrotalcite particles contain fluorine derived from a surface treatment agent, the graph of the X-ray intensity normalized by the peak intensity has peaks near the points a and b at both ends of the fluorine graph, as shown in Figure 9(c). By checking the X-ray intensities derived from fluorine and aluminum in the line analysis, it can be confirmed that the hydrotalcite particles contain fluorine and aluminum inside.

[0126] <Calculation method for the ratio of the atomic concentration of fluorine to aluminum in hydrotalcite particles (element ratio) F / Al> The ratio of the atomic concentration of fluorine to aluminum in the hydrotalcite particles (element ratio) F / Al obtained from the main component mapping derived from the hydrotalcite particles by the above-mentioned STEM-EDS mapping analysis is obtained in multiple fields of view.Then, the arithmetic average of 100 or more applicable particles is taken to obtain the ratio of the atomic concentration of fluorine to aluminum in the hydrotalcite particles (element ratio) F / Al.

[0127] <Calculation method for the ratio of the atomic concentration of magnesium to aluminum in hydrotalcite particles (element ratio) Mg / Al> The same method as the calculation method for the atomic concentration ratio (element ratio) F / Al of fluorine to aluminum in the hydrotalcite particles described above is performed for magnesium and aluminum, and the atomic concentration ratio (element ratio) Mg / Al of magnesium to aluminum in the hydrotalcite particles is calculated.

[0128] <Method for calculating fluorine atom number concentration in hydrotalcite particles> The atomic concentration of fluorine in the hydrotalcite particles is calculated based on the mapping data obtained by the STEM-EDS mapping analysis using the above-mentioned method. The atomic concentration of fluorine (element amount) in the hydrotalcite particles is quantified in the main component map image of the hydrotalcite particles extracted using the above-mentioned method.

[0129] The mapping data is obtained from multiple fields of view, and the data is collected for more than 100 hydrotalcite particles. The arithmetic average is taken as the fluorine atom number concentration in the hydrotalcite particles.

[0130] <Method for measuring number average particle size of primary particles of hydrotalcite particles> The number average particle size S3 of the primary particles of the hydrotalcite particles is measured using a scanning electron microscope "S-4800" (product name; manufactured by Hitachi, Ltd.) in combination with elemental analysis using energy dispersive X-ray analysis (EDS). The toner to which hydrotalcite particles have been added as an external additive is observed, and the hydrotalcite particles are photographed in a field of view magnified up to 200,000 times. From the photographed image, hydrotalcite particles are selected, and the major axis of the primary particles of 100 hydrotalcite particles is measured at random to determine the number average particle size of the hydrotalcite particles. The observation magnification is adjusted appropriately depending on the size of the external additive.

[0131] <Method for measuring adhesion rate of hydrotalcite particles to toner particles> First, two types of samples (toner before washing and toner after washing) are prepared. (i) Toner before washing: Various toners prepared in the examples described later are used as they are. (ii) Toner after washing: Add 160 g of sucrose (Kishida Chemical) to 100 mL of ion-exchanged water and dissolve in a hot water bath to prepare a concentrated sucrose solution. Add 31 g of the concentrated sucrose solution and 6 mL of Contaminon N (a 10% aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, anionic surfactant, and organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) to a centrifuge tube to prepare a dispersion. Add 1 g of toner to this dispersion, and break up the toner clumps with a spatula or the like. Shake the centrifuge tube in a shaker at 5.8 s-1 for 20 min.

[0132] After shaking, transfer the solution to a glass tube (50 mL) for a swing rotor and centrifuge it at 58.3 s-1, 30 min. Visually check that the toner and aqueous solution are sufficiently separated, and collect the toner that has separated to the top layer with a spatula, etc. After filtering the collected aqueous solution containing the toner with a vacuum filter, dry it in a dryer for at least 1 hour to prepare a sample.

[0133] For these samples before and after water washing, SEM / EDS observation is performed on a visual field aligned with the center of 20 toner particles randomly selected under the conditions below, and the total area of ​​the hydrotalcite particles is calculated. The adhesion rate of the hydrotalcite particles is calculated using the following formula. Adhesion rate of hydrotalcite particles (%)=(total area of ​​hydrotalcite particles of toner after washing with water) / (total area of ​​hydrotalcite particles of toner before washing with water)×100

[0134] The SEM / EDS equipment and observation conditions are as follows. Equipment used (SEM): ULTRA PLUS manufactured by Carl Zeiss Microscopy Co., Ltd. Equipment used (EDS): NORAN manufactured by Thermo Fisher Scientific Co., Ltd. System 7, Ultra Dry EDS Detector Accelerating voltage: 5.0 kV WD:7.0mm Aperture Size: 30.0μm Detection signal: SE2 (secondary electrons) Magnification: 50,000x Mode:Spectral Imaging Pretreatment: Sample toner is spread on carbon tape and platinum sputtered.

[0135] The present disclosure will be described in more detail below with reference to examples and comparative examples, but the present disclosure is in no way limited thereto. "Parts" used in the examples are by mass unless otherwise specified. An example of toner production will now be described.

[0136] <Toner particle manufacturing example> <Preparation of aqueous dispersion medium> ·Wednesday 390.0 copies Sodium phosphate 4.2 parts The above aqueous solution was prepared and kept at 60° C. while stirring at high speed to prepare an aqueous sodium phosphate solution. ·Wednesday 17.1 parts 2.4 parts calcium chloride After the above aqueous solution was prepared, it was added to the above aqueous sodium phosphate solution and stirred at high speed to prepare an aqueous dispersion medium containing calcium phosphate fine particles.

[0137] <Preparation of Polymerizable Monomer Composition 1> Styrene 30.0 parts CI Pigment Blue 15:3 6.0 parts Charge control agent (aluminum complex) 0.5 parts The above materials were dispersed in an attritor at room temperature for 5 hours to obtain a polymerizable monomer composition 1.

[0138] <Preparation of polymerizable monomer composition 2> Polymerizable monomer composition 1 46.8 parts Styrene 39.0 parts n-Butyl acrylate 25.0 parts Polar Resin 1 10.0 parts (styrene-methacrylic acid-methyl methacrylate-2-hydroxyethyl methacrylate copolymer, Mw=15200) Polar Resin 2 4.0 parts (Polyester resin, a polycondensation product of propylene oxide modified bisphenol A and terephthalic acid, Mw=9500) Polar Resin 3 1.0 parts (Styrene-2-ethylhexyl acrylate copolymer containing 10% by mass of 2-acrylamide-2-methylpropanesulfonic acid, Mp=18000) Behenyl behenate 6.0 parts Hydrocarbon wax (melting point 78°C) 3.0 parts The above materials were charged into a temperature-controllable stirring tank, heated to 60° C., and stirred for 1 hour to obtain a polymerizable monomer composition 2.

[0139] <Granulation, polymerization process> The above polymerizable monomer composition 2 was added to the aqueous dispersion medium, and 7.0 parts of a polymerization initiator was added, and the mixture was granulated for 10 minutes while maintaining high-speed stirring at a temperature of 60°C. The stirrer was then changed to a propeller stirrer, and the mixture was heated to 70°C and reacted for 5 hours. The mixture was further heated to 80°C and reacted for 5 hours, and then cooled to obtain a polymer microparticle dispersion.

[0140] <Cleaning, drying, and classification processes> 10% hydrochloric acid was added to the above polymer particle dispersion to dissolve the calcium phosphate particle dispersant, which was then filtered, washed, dried, and classified using an air classifier to obtain toner particles with a weight average particle size of 5.8 μm.

[0141] <Preparation of Hydrotalcite Particles 1> 3.5 parts sodium fluoride ·Wednesday 350.0 parts

[0142] The above aqueous solution was prepared, and 3.5 parts of hydrotalcite (number average particle size of primary particles: 240 nm) was added. The mixture was stirred at room temperature for 10 hours, filtered, dried, and crushed to obtain hydrotalcite particles 1. Line analysis in STEM-EDS mapping analysis confirmed the presence of fluorine inside hydrotalcite particles 1, with F / Al=0.11 and Mg / Al=2.45.

[0143] <Hydrotalcite particles 2> The hydrotalcite (primary particle number average particle size: 240 nm) used in the preparation of hydrotalcite particles 1 was designated as hydrotalcite particles 2. In line analysis in the STEM-EDS mapping analysis, the presence of fluorine inside hydrotalcite particles 2 could not be confirmed.

[0144] <Preparation of Hydrotalcite Particles 3> Methanol 50.0 parts Fluorine-containing silicone (X-12-2430C, Shin-Etsu Silicone Co., Ltd.) 0.3 parts Hydrotalcite (number-average particle size of primary particles: 240 nm) 5.0 parts The above materials were added and stirred at room temperature for 10 hours, and then 500 parts of water was added and stirred for another hour, followed by filtration, drying and crushing to obtain hydrotalcite particles 3. In a line analysis in a STEM-EDS mapping analysis, the presence of fluorine was not confirmed inside the hydrotalcite particles 3, but the presence of fluorine was confirmed on the surface of the hydrotalcite particles 3.

[0145] <Toner 1 Manufacturing Example> To the toner particles (100.0 parts) obtained above, hydrotalcite particles 1 (0.3 parts) and hydrophobic treated silica (BET380m 2 / g) (1.0 part) was externally added and mixed using a Mitsui Henschel mixer (Mitsui Miike Chemical Engineering Co., Ltd.) The external addition conditions were adjusted such as the stirring rotation speed and mixing time so as to obtain a desired adhesion rate.

[0146] Thereafter, the mixture was sieved through a mesh having an opening of 200 μm to obtain Toner 1. The adhesion rate of the hydrotalcite particles to the toner particles was 30%.

[0147] <Toner 2 Manufacturing Example> Toner 2 was obtained in the same manner as in the production example of toner 1, except that the hydrotalcite particles used in the production example of toner 1 were changed to hydrotalcite particles 2.

[0148] <Toner 3 Manufacturing Example> Toner 3 was obtained in the same manner as in the production example of toner 1, except that the hydrotalcite particles used in the production example of toner 1 were changed to hydrotalcite particles 3.

[0149] [Confirmation of the effect of the present invention] For each of the above toner and the developing blade 35 with and without the "capture area J" at the leading edge, 5,000 sheets of horizontal lines with an image ratio of 1% were printed continuously under conditions of a temperature of 15°C and a humidity of 10% RH, and the effects were confirmed. The toner of this embodiment is Toner 1, and the toners of the comparative examples are Toner 2 and Toner 3.

[0150] To verify the effect, a reflection densitometer (Model TC-MOR-45, manufactured by Tokyo Denshoku Co., Ltd., using a green filter) was used to measure the reflectance (%) in order to measure the fog density caused by poor regulation. The fog measurement was performed by attaching a post-it note or the like to a part of the paper to be printed. An image of the background is formed and the paper is output. The reflectance of the part of the output paper from which the Post-it note was removed is used as the reference reflectance of the paper itself, and fogging is measured. The reflectance varies depending on the part being measured, and the difference between the measured value of the part with the smallest value and the measured value of the part with the Post-it note attached (reference reflectance) is measured as the fogging value. The smaller the measured fogging value, the less the amount of fogging, and therefore the better the image quality.

[0151] In addition, a solid black image was formed on the entire surface, and the image density was measured using a densitometer (manufactured by eXact x-rite).

[0152] In this evaluation, when toner 2 and toner 3 were used, when the developing roller 25 was brought into contact to obtain the desired image density, fogging due to poor regulation occurred to a level that was intolerable in practical use, both when the developing blade 35 with the "capture area J" at the leading edge was used and when the developing blade 35 without the "capture area J" at the leading edge was used. The desired density was 1.3 as the value of the densitometer, and the level of fogging that was intolerable in practical use was fogging of 5% or more. It is believed that the poor regulation occurred with the toner that does not contain fluorine because excessive charges were applied by the hydrotalcite particles.

[0153] In addition, when a developing blade 35 that does not have a sufficient "capture area J" at the leading edge portion of the toner 1 was used, when the developing roller 25 was brought into contact with the toner 1 to obtain a desired image density, a regulation failure occurred to a level that was unsuitable for practical use.

[0154] On the other hand, when toner 1 and the developing blade 35 having the "capture area J" at the leading edge were used, the desired image density was obtained and the occurrence of regulation failure was suppressed.

[0155] In other words, by using toner to which fluorine-containing hydrotalcite is externally added and a developing blade 35 having a "capture area J" at the leading edge portion, it is possible to obtain good image quality.

[0156] In this embodiment, the developing blade 35 has a tip edge portion ground to form the "capture area J", but the present invention is not limited to this.

[0157] For example, a similar effect can be obtained by using a developing blade 35 whose leading edge is bent at a predetermined radius of curvature as shown in Fig. 10. Even when using a developing blade 35 whose leading edge is bent as shown in Fig. 10, a point F on the developing blade 35 that is farther away from the developing roller 25 than the volume average particle diameter R of the toner exists in the "take-in area J" of the leading edge of the developing blade 35, and the width d2 of the take-in area on the free end side of point F is larger than the volume average particle diameter R of the toner, so it is believed that a similar effect can be obtained.

[0158] [Configuration 1] A process cartridge that can be mounted in an image forming apparatus, a photosensitive drum as an image carrier, a developing roller for developing a toner image on the photosensitive drum, a supply roller for supplying toner to the developing roller; a developing chamber having a support portion for axially supporting the developing roller and the supply roller; a developing blade for regulating the thickness of a toner layer on the developing roller; a toner having toner particles having a volume average particle size R and an external additive; a toner storage section for storing the toner, the toner storage section is configured to communicate with the developing chamber through a communication port, the developing roller is configured so that the moving direction of the surface of the developing roller is opposite to the moving direction of the surface of the supply roller at the contact position with the supply roller; in a cross section of the process cartridge in a plane perpendicular to the rotation axis of the developing roller when the process cartridge is mounted in the main body of the image forming apparatus, a location where the developing blade contacts the developing roller is vertically below a horizontal line H1 passing through a center of the rotation axis of the developing roller; A driving force receiving portion is provided. a first driving force transmitting portion for transmitting the driving force from the driving force receiving portion to the supply roller; a second driving force transmission portion provided on the supply roller for transmitting the driving force received by the first driving force transmission portion to the developing roller; a third driving force transmission unit provided on the developing roller and configured to transmit a driving force from the second driving force transmission unit to the developing roller; A process cartridge having the toner contains hydrotalcite particles as the external additive, In a line analysis in a STEM-EDS mapping analysis of the toner, fluorine is present inside the hydrotalcite particles, The developing blade is made of a plate-shaped metallic elastic blade and a blade support portion for supporting the elastic blade. In a cross section of the process cartridge taken along a plane perpendicular to the rotation axis of the developing roller, The elastic blade is in contact with the developing roller to form a nip N1. A point on the elastic blade at the end of the nip N1 on the upstream side in the rotation direction of the developing roller is defined as point D. A point on the elastic blade that is closest to the surface of the developing roller is designated as point B. A point E is a point where a perpendicular line drawn from point B to the surface of the developing roller intersects with the surface of the developing roller. a point F on the surface of the elastic blade that is closest to the free end of the elastic blade and has a distance R from the surface of the developing roller; When the point G on the straight line BE is at a distance R from the surface of the developing roller, the distance GF is equal to or greater than R. A process cartridge comprising: [Configuration 2] A process cartridge that can be mounted in an image forming apparatus, a photosensitive drum as an image carrier, a developing roller for developing a toner image on the photosensitive drum, a supply roller for supplying toner to the developing roller; a developing chamber having a support portion for axially supporting the developing roller and the supply roller; a developing blade for regulating the thickness of a toner layer on the developing roller; a toner having toner particles having a volume average particle size R and an external additive; a toner storage section for storing the toner, the toner storage section is configured to communicate with the developing chamber through a communication port, The direction of movement of the surface of the developing roller at the contact position with the supply roller is as follows: The direction of movement of the surface of the supply roller is opposite to the direction of movement of the supply roller. The developing blade is made of a plate-shaped metallic elastic blade and a blade support portion for supporting the elastic blade. In a cross section of the process cartridge taken along a plane perpendicular to the rotation axis of the developing roller, a straight line A connecting the rotational centers of the supply roller and the developing roller is inclined at an angle of approximately 9.85° from the horizontal, the rotational axis center of the supply roller is below the rotational axis center of the developing roller, and the rotational axis center of the photosensitive drum is above the straight line A. In this state, the location where the elastic blade contacts the developing roller is below the rotational axis center of the developing roller, A driving force receiving portion is provided. a first driving force transmitting portion for transmitting the driving force from the driving force receiving portion to the supply roller; a second driving force transmission portion provided on the supply roller for transmitting the driving force received by the first driving force transmission portion to the developing roller; a third driving force transmission unit provided on the developing roller and configured to transmit a driving force from the second driving force transmission unit to the developing roller; A process cartridge, the toner contains hydrotalcite particles as the external additive, In a line analysis in a STEM-EDS mapping analysis of the toner, fluorine is present inside the hydrotalcite particles, In a cross section of the process cartridge taken along a plane perpendicular to the rotation axis of the developing roller, The elastic blade is in contact with the developing roller to form a nip N1. A point on the elastic blade at the end of the nip N1 on the upstream side in the rotation direction of the developing roller is defined as point D. A point on the elastic blade that is closest to the surface of the developing roller is designated as point B. A point E is a point where a perpendicular line drawn from point B to the surface of the developing roller intersects with the surface of the developing roller. a point F on the surface of the elastic blade that is closest to the free end of the elastic blade and has a distance R from the surface of the developing roller; When the point G on the straight line BE is at a distance R from the surface of the developing roller, the distance GF is equal to or greater than R. A process cartridge comprising: [Configuration 3] When a tangent line at a point F on the surface of the elastic blade is a straight line L4, an angle θ between the straight line L4 and a straight line DE is in the range of 0°<θ<45°. 3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 4] The angle θ is in the range of 0°<θ<25°. 4. The process cartridge according to claim 3, [Configuration 5] The distance between any point on the elastic blade between the point D and the surface of the developing roller increases as the point moves away from the point D. 5. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 6] The distance of the FG is 20 μm or more. 6. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 7] A second driving force receiving portion for transmitting a driving force to at least the photosensitive drum is provided. 7. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 8] The developing roller and the supply roller are drive-coupled to rotate by the driving force from the driving force receiving portion such that the peripheral speed ratio R, which is expressed by the following formula (E1), satisfies R>1.0. R = Vrs / Vd (E1) (In formula (E1), Vrs represents the absolute value [mm / sec] of the peripheral speed of the supply roller, and Vd represents the absolute value [mm / sec] of the peripheral speed of the developing roller.) 8. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 9] When the radius of the developing roller is Rd [mm] and the radius of the supply roller is Rrs [mm], The second driving force transmission unit and the third driving force transmission unit have a rotation angle represented by the following formula (E2): The drive connection is made so that the speed ratio λ satisfies λ×Rrs / Rd>1.0. λ = ωrs / ωd (E2) (In formula (E2), ωrs represents the rotational angular velocity [rad / sec] of the supply roller, and ωd represents the rotational angular velocity [rad / sec] of the development roller.) 9. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 10] The developing chamber does not have a stirring member for stirring the toner. 10. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 11] Among the members supported in the developing chamber, the only members supported so as to be capable of transmitting the driving force from the driving force receiving portion are the developing roller and the supply roller. 11. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 12] the elastic blade is supported so as to have flexibility between a support end supported by the blade support portion and the other free end when the elastic blade is attached to the main body of the image forming apparatus, If a horizontal line passing through the support end is a straight line H2, then at least a part of the inner wall of the developing chamber located vertically below the supply roller is located vertically above the straight line H2 between two tangents that are tangent to the outer circumferential surface of the supply roller and extend in the vertical direction. 12. The process cartridge according to claim 1, wherein the process cartridge is a process cartridge having a first opening and a second opening. [Configuration 13] A conveying member for conveying the toner, the conveying member is a member having elasticity and conveying the toner by rotating, The conveying member is rotatably supported in the toner storage chamber. 13. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 14] In a state where the image forming apparatus is mounted in the main body of the image forming apparatus, the communication port is disposed above the toner storage unit, the transport member is a member that has elasticity and transports the toner by rotating, a deformation portion that is provided in the toner storage portion so as to come into contact with a free end side of the conveying member at a position upstream of the communication opening in a rotation direction of the conveying member, and that deforms the conveying member against the elasticity as the conveying member rotates so that the free end side is located upstream of the rotation shaft side of the conveying member in the rotation direction of the conveying member; a restoring portion that is provided in the toner storage portion at a position downstream of the deformation portion in the rotation direction of the transport member and upstream of the communication opening in the rotation direction of the transport member so that a tip end of a free end side of the transport member is released from contact, and that restores the transport member deformed by the deformation portion by means of the elasticity in order to cause the toner on the transport member to fly toward the communication opening, In the attached state, a boundary portion between the deformation portion and the restoration portion is provided below a lower end of the communication port, When viewed from the axial direction of the developing roller, a rotation center of the conveying member and a rotation center of the developing roller are on the same side with respect to a vertical line passing through the boundary portion, The maximum value of the rotation radius of the conveying member is greater than the distance between the rotation center of the conveying member and the lower end of the communication port. 14. The process cartridge according to claim 13, [Configuration 15] the conveying member is made of a rotating shaft and a flexible sheet member fixed to the rotating shaft, The sheet member is fixed at a plurality of different phases around the agitation shaft. 15. The process cartridge according to claim 13, wherein the first and second ink cartridges are arranged on the first and second sides. [Configuration 16] The elastic blade is The tip shape where point D exists is formed by polishing the surface of the elastic blade. Characterized by 16. The process cartridge according to claim 1. [Configuration 17] The elastic blade is The tip shape where the point D exists is formed by bending the tip of a metallic plate-shaped elastic member in the direction opposite to the developing roller contact surface side. 16. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 18] In a line analysis in a STEM-EDS mapping analysis of the toner, fluorine and aluminum are present inside the hydrotalcite particles, a ratio (F / Al) of the atomic concentration (atomic %) of the fluorine in the hydrotalcite particles to the atomic concentration (atomic %) of the aluminum in the hydrotalcite particles, which is obtained from main component mapping of the hydrotalcite particles by STEM-EDS mapping analysis of the toner, is 0.01 to 0.65. 18. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 19] The adhesion rate of the hydrotalcite particles to the toner particles is 10% or more. 19. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 20] The hydrotalcite particles contain magnesium. 20. The process cartridge according to claim 1, wherein the first and second electrodes are arranged in a first direction. [Configuration 21] The ratio (Mg / Al) of the atomic concentration (atomic %) of magnesium to the atomic concentration (atomic %) of aluminum in the hydrotalcite particles is 1.5 to 4.0. 21. The process cartridge according to claim 20, [Configuration 22] 22. The process cartridge according to claim 1, wherein the number average particle size of primary particles of the hydrotalcite particles is 60 to 1000 nm. [Explanation of symbols]

[0159] 1: photosensitive drum, 25: developing roller, 31a: toner storage chamber, 31b: developing chamber, 34: toner supply roller, 36: toner transport member, 70: process cartridge, 811: first portion, 812: second portion, 813: third portion

Claims

1. A process cartridge that can be mounted in an image forming apparatus, A photosensitive drum as an image carrier, a developing roller for developing a toner image on the photosensitive drum, a supply roller for supplying toner to the developing roller; a developing chamber having a support portion for axially supporting the developing roller and the supply roller; a developing blade for regulating the thickness of a toner layer on the developing roller; a toner having toner particles having a volume average particle size R and an external additive; a toner storage section for storing the toner, the toner storage section is configured to communicate with the developing chamber through a communication port, the developing roller is configured so that the moving direction of the surface of the developing roller is opposite to the moving direction of the surface of the supply roller at the contact position with the supply roller; in a cross section of the process cartridge in a plane perpendicular to the rotation axis of the developing roller when the process cartridge is mounted in the main body of the image forming apparatus, a location where the developing blade contacts the developing roller is vertically below a horizontal line H1 passing through a center of the rotation axis of the developing roller; A driving force receiving portion is provided. a first driving force transmitting portion for transmitting a driving force from the driving force receiving portion to the supply roller; a second driving force transmission portion provided on the supply roller for transmitting the driving force received by the first driving force transmission portion to the developing roller; a third driving force transmission unit provided on the developing roller and configured to transmit a driving force from the second driving force transmission unit to the developing roller; A process cartridge having the toner contains hydrotalcite particles as the external additive, In a line analysis in a STEM-EDS mapping analysis of the toner, fluorine is present inside the hydrotalcite particles, The developing blade is made of a plate-shaped metallic elastic blade and a blade support portion for supporting the elastic blade. In a cross section of the process cartridge taken along a plane perpendicular to the rotation axis of the developing roller, The elastic blade is in contact with the developing roller to form a nip N1. A point on the elastic blade at the end of the nip N1 on the upstream side in the rotation direction of the developing roller is defined as point D. A point on the elastic blade that is closest to the surface of the developing roller is designated as point B. A point E is a point where a perpendicular line drawn from point B to the surface of the developing roller intersects with the surface of the developing roller. a point F on the surface of the elastic blade that is closest to the free end of the elastic blade and has a distance R from the surface of the developing roller; When a point on a straight line BE whose distance from the surface of the developing roller is R is G, the distance GF is equal to or greater than R. A process cartridge comprising:

2. A process cartridge that can be mounted in an image forming apparatus, A photosensitive drum as an image carrier, a developing roller for developing a toner image on the photosensitive drum, a supply roller for supplying toner to the developing roller; a developing chamber having a support portion for axially supporting the developing roller and the supply roller; a developing blade for regulating the thickness of a toner layer on the developing roller; a toner having toner particles having a volume average particle size R and an external additive; a toner storage section for storing the toner, the toner storage section is configured to communicate with the developing chamber through a communication port, The direction of movement of the surface of the developing roller at the contact position with the supply roller is as follows: The direction of movement of the surface of the supply roller is opposite to the direction of movement of the supply roller. The developing blade is made of a plate-shaped metallic elastic blade and a blade support portion for supporting the elastic blade. In a cross section of the process cartridge taken along a plane perpendicular to the rotation axis of the developing roller, a straight line A connecting the rotational centers of the supply roller and the developing roller is inclined at an angle of approximately 9.85° from the horizontal, the rotational axis center of the supply roller is below the rotational axis center of the developing roller, and the rotational axis center of the photosensitive drum is above the straight line A. In this state, the location where the elastic blade contacts the developing roller is below the rotational axis center of the developing roller, A driving force receiving portion is provided. a first driving force transmitting portion for transmitting a driving force from the driving force receiving portion to the supply roller; a second driving force transmission portion provided on the supply roller for transmitting the driving force received by the first driving force transmission portion to the developing roller; a third driving force transmission portion provided on the developing roller and configured to transmit a driving force from the second driving force transmission portion to the developing roller; A process cartridge, the toner contains hydrotalcite particles as the external additive, In a line analysis in a STEM-EDS mapping analysis of the toner, fluorine is present inside the hydrotalcite particles, In a cross section of the process cartridge taken along a plane perpendicular to the rotation axis of the developing roller, The elastic blade is in contact with the developing roller to form a nip N1. A point on the elastic blade at the end of the nip N1 on the upstream side in the rotation direction of the developing roller is defined as point D. A point on the elastic blade that is closest to the surface of the developing roller is designated as point B. A point E is a point where a perpendicular line drawn from point B to the surface of the developing roller intersects with the surface of the developing roller. a point F on the surface of the elastic blade that is closest to the free end of the elastic blade and has a distance R from the surface of the developing roller; When a point on a straight line BE whose distance from the surface of the developing roller is R is G, the distance GF is equal to or greater than R. A process cartridge comprising:

3. When a tangent line at a point F on the surface of the elastic blade is a straight line L4, an angle θ between the straight line L4 and a straight line DE is in the range of 0°<θ<45°.

3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

4. The angle θ is in the range of 0°<θ<25°.

4. The process cartridge according to claim 3,

5. The distance between any point on the elastic blade from point D to point B and the surface of the developing roller increases as the point moves away from point D.

3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

6. The FG distance is 20 μm or more.

3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

7. A second driving force receiving portion for transmitting a driving force to at least the photosensitive drum is provided.

3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

8. The developing roller and the supply roller are drive-coupled to rotate by the driving force from the driving force receiving portion such that the peripheral speed ratio R, which is expressed by the following formula (E1), satisfies R>1.

0. R=Vrs / Vd...(E1) (In formula (E1), Vrs represents the absolute value of the peripheral speed of the supply roller [mm / sec], and Vd represents the absolute value of the peripheral speed of the developing roller [mm / sec].) 3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

9. When the radius of the developing roller is Rd [mm] and the radius of the supply roller is Rrs [mm], The second driving force transmission portion and the third driving force transmission portion are drivingly connected to each other so that a rotational angular velocity ratio λ expressed by the following formula (E2) satisfies λ×Rrs / Rd>1.

0. λ=ωrs / ωd...(E2) (In formula (E2), ωrs represents the rotational angular velocity [rad / sec] of the supply roller, and ωd represents the rotational angular velocity [rad / sec] of the developing roller.) 3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

10. The developing chamber does not have a stirring member for stirring the toner.

3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

11. Among the members supported in the developing chamber, the only members supported so as to be capable of transmitting the driving force from the driving force receiving portion are the developing roller and the supply roller.

3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

12. the elastic blade is supported so as to have flexibility between a support end supported by the blade support portion and the other free end when the elastic blade is attached to the main body of the image forming apparatus, If a horizontal line passing through the support end is a straight line H2, then at least a part of the inner wall of the developing chamber located vertically below the supply roller is located vertically above the straight line H2 between two tangents that are tangent to the outer circumferential surface of the supply roller and extend in the vertical direction.

3. The process cartridge according to claim 1, wherein the first and second ink cartridges are arranged on the first and second sides of the ink cartridge.

13. A conveying member for conveying the toner, the conveying member is a member having elasticity and conveying the toner by rotating, The conveying member is rotatably supported in the toner storage chamber.

3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

14. In a state where the image forming apparatus is mounted in the main body of the image forming apparatus, the communication port is disposed above the toner storage unit, the transport member is a member that has elasticity and transports the toner by rotating, a deformation portion that is provided in the toner storage portion so as to come into contact with a free end side of the conveying member at a position upstream of the communication opening in a rotation direction of the conveying member, and that deforms the conveying member against the elasticity as the conveying member rotates so that the free end side is located upstream of the rotation shaft side of the conveying member in the rotation direction of the conveying member; a restoring portion that is provided in the toner storage portion so that a tip end of the free end side of the conveying member is released from contact at a position downstream of the deformation portion in the rotation direction of the conveying member and upstream of the communication opening in the rotation direction of the conveying member, and that restores the conveying member deformed by the deformation portion by the elasticity in order to cause the toner on the conveying member to fly toward the communication opening. and In the attached state, a boundary portion between the deformation portion and the restoration portion is provided below a lower end of the communication port, When viewed from the axial direction of the developing roller, a rotation center of the conveying member and a rotation center of the developing roller are on the same side with respect to a vertical line passing through the boundary portion, The maximum value of the rotation radius of the conveying member is greater than the distance between the rotation center of the conveying member and the lower end of the communication port.

14. The process cartridge according to claim 13.

15. the conveying member is made of a rotating shaft and a flexible sheet member fixed to the rotating shaft, The sheet member is fixed at a plurality of different phases around the agitation shaft.

14. The process cartridge according to claim 13.

16. The elastic blade is The tip shape where the point D exists is formed by polishing the surface of the elastic blade. Characterized by 3. The process cartridge according to claim 1.

17. The elastic blade is The tip shape where the point D exists is formed by bending the tip of a metal plate-shaped elastic member in the direction opposite to the developing roller contact surface side.

3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

18. In a line analysis in a STEM-EDS mapping analysis of the toner, fluorine and aluminum are present inside the hydrotalcite particles, a ratio (F / Al) of the atomic concentration (atomic %) of the fluorine in the hydrotalcite particles to the atomic concentration (atomic %) of the aluminum in the hydrotalcite particles, the ratio being obtained from main component mapping of the hydrotalcite particles by STEM-EDS mapping analysis of the toner, is 0.01 to 0.65; 3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

19. The adhesion rate of the hydrotalcite particles to the toner particles is 10% or more.

3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

20. The hydrotalcite particles contain magnesium.

3. The process cartridge according to claim 1, wherein the first and second electrodes are arranged on the first and second surfaces.

21. The ratio (Mg / Al) of the atomic concentration (atomic %) of magnesium to the atomic concentration (atomic %) of aluminum in the hydrotalcite particles is 1.5 to 4.

0.

21. The process cartridge according to claim 20.

22. 3. The process cartridge according to claim 1, wherein the number average particle size of the primary particles of the hydrotalcite particles is 60 to 1000 nm.

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