JP7346162B2 - Developing device, process cartridge and image forming device - Google Patents

Description

The present invention relates to a developing device, a process cartridge, and an image forming apparatus. In particular, the present invention relates to an electrophotographic image forming apparatus and a developing device and a process cartridge used in the electrophotographic image forming apparatus.

Generally, a developing device includes a frame body that accommodates toner and a developing roller, and the amount of toner carried on the developing roller is regulated by a developing blade.

Note that one end (free end) of the developing blade that comes into contact with the developing roller is approximately L-shaped on the developing roller side so that the contact pressure (pressure per unit area) of the developing blade against the developing roller can be easily obtained. There is a structure in which it is bent on the opposite side.

For example, in the developing blade disclosed in Patent Document 1, after its free end is bent at a predetermined radius of curvature, the tip (free end) of the developing blade extends away from the surface of the developing roller.

Japanese Patent Application Publication No. 2010-170021

In the developing blade as disclosed in Patent Document 1, when the radius of curvature of the bent portion is increased, the region (area) that can come into contact with the developing roller increases, and the contact pressure tends to be dispersed (reduced). As a result, it becomes difficult to secure the contact pressure (especially "peak pressure") from the developing blade against the developing roller, and the toner on the developing roller may not be effectively regulated (in other words, there is a possibility of "poor regulation"). be.

On the other hand, when the radius of curvature of the bent part is made smaller, the outer circumferential side (abutting side) of the bent part is stretched, and a "burr-like" uneven shape (cracks) occurs on the outer circumferential surface (abutting surface). There are cases where Toner tends to adhere to the uneven surface, and poor regulation may occur due to the toner adhering to the developing blade being fused to the developing blade due to sliding friction with the developing roller. In particular, since conventionally used developers may include those with low hardness, toner tends to adhere to the developing blade, which tends to deteriorate the fusion of the toner to the developing blade.

The present invention has been made in view of the above problems, and is capable of reducing the fusion of developer to the regulating member while ensuring the contact pressure (peak pressure) of the regulating member with respect to the developer carrier. The object of the present invention is to provide a developing device, a process cartridge, or an image forming device that can be used.

The developing device of the present invention includes:
a developer carrier that carries a developer;
a developing frame body rotatably supporting the developer carrier;
A developing device comprising: a regulating member attached to the developing frame and regulating the thickness of the developer carried on the developer carrier by coming into contact with the surface of the developer carrier,
The regulating member is
a curved surface portion having a ridge line that can come into contact with the surface of the developer carrier;
When the Martens hardness under the condition of a maximum load of 2.0×10 ⁻⁴ N of the toner contained in the developer is HM, and the radius of curvature of the curved surface portion is Rb,
200MPa≦HM≦1100MPa,
0.08mm≦Rb≦ 0.3mm ,
The toner particles of the toner are characterized in that they have a surface layer containing an organosilicon polymer .

Further, the process cartridge of the present invention is characterized in that it includes the developing device and an image carrier that carries a developer image.

The image forming apparatus of the present invention is characterized in that it includes the developing device, an image carrier that carries a developer image, and a transfer member that transfers the developer image from the image carrier to a recording material. shall be.

According to the present invention, it is possible to reduce the fusion of developer to the regulating member while ensuring the contact pressure (peak pressure) of the regulating member with respect to the developer carrier.

Schematic sectional view of an image forming apparatus according to an embodiment Schematic sectional view of a process cartridge according to an embodiment Conceptual cross-sectional diagram of the vicinity of the end of the developing roller in the example Conceptual cross-sectional diagram of a developing blade in an example Schematic diagram of a toner having a surface layer containing an organosilicon compound in an example (a) Diagram showing the method for measuring the radius of curvature R of the curved portion of the developing blade in Examples; (b) Diagram showing the measurement results of the radius of curvature R An explanatory diagram of the arrangement configuration of a process cartridge according to an embodiment

In the present invention, the descriptions such as "○○ or more and XX or less" or "○○ to XX" expressing a numerical range mean a numerical range that includes the lower limit and the upper limit, which are the end points, unless otherwise specified.

EMBODIMENT OF THE INVENTION Below, with reference to drawings, the form for implementing this invention is illustratively described in detail based on an Example. However, the dimensions, materials, shapes, and relative arrangement of the components described in this embodiment should be changed as appropriate depending on the configuration of the device to which the invention is applied and various conditions. That is, the scope of the present invention is not intended to be limited to the following embodiments.

<Overall schematic configuration of image forming apparatus>
Referring to FIG. 1, the overall configuration of an electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) according to an embodiment of the present invention will be described. FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 of this embodiment. Image forming apparatuses to which the present invention can be applied include copying machines, printers, facsimile machines, etc. that utilize electrophotography, and here, a case where the present invention is applied to a laser printer will be described. The image forming apparatus 100 of this embodiment is a full-color laser printer that employs an in-line method and an intermediate transfer method. The image forming apparatus 100 can form a full-color image on a recording material (eg, recording paper, plastic sheet, cloth, etc.) according to image information. Image information is input to the image forming apparatus main body 100A from an image reading device connected to the image forming apparatus main body 100A or a host device such as a personal computer communicably connected to the image forming apparatus main body 100A.

The image forming apparatus 100 includes a plurality of image forming sections, a first, a second, and a third for forming images of each color of yellow (Y), magenta (M), cyan (C), and black (K), respectively. , fourth image forming sections SY, SM, SC, and SK. In this embodiment, the first to fourth image forming units SY, SM, SC, and SK are arranged in a line in a direction intersecting the vertical direction. In this embodiment, the configurations and operations of the first to fourth image forming sections SY, SM, SC, and SK are substantially the same except that the colors of the images to be formed are different. Therefore, in the following, unless a particular distinction is required, the suffixes Y, M, C, and K given to the symbols to indicate elements provided for one of the colors will be omitted, and they will be generally referred to as explain.

In this embodiment, the image forming apparatus 100 includes four drum-shaped electrophotographic photosensitive members, that is, photosensitive drums 1, which are arranged in parallel in a direction intersecting the vertical direction, as a plurality of image carriers. The photosensitive drum 1 is rotationally driven in the direction of arrow A (clockwise) in the figure by a drive means (drive source) not shown. Around the photosensitive drum 1, there is a charging roller 2 as a charging means that charges the surface of the photosensitive drum 1 uniformly, and an electrostatic image (electrostatic latent image) is formed on the photosensitive drum 1 by irradiating a laser with a laser based on image information. A scanner unit (exposure device) 3 is arranged as an exposure means for forming. Further, around the photosensitive drum 1, there is a developing unit (developing device) 4 as a developing means for developing the electrostatic image as a toner image (developer image), and a toner remaining on the surface of the photosensitive drum 1 after transfer. A cleaning member 6 is disposed as a cleaning means for removing. Further, an intermediate transfer belt 5 serving as an intermediate transfer body for transferring the toner image on the photosensitive drums 1 onto the recording material 12 is arranged above the photosensitive drums 1 so as to face the four photosensitive drums 1 .

In this embodiment, the developing unit 4 as a developing device uses toner, which is a non-magnetic one-component developer, as a developer. Further, in this embodiment, the developing unit 4 performs reversal development by bringing a developing roller serving as a developer carrier into contact with the photosensitive drum 1. That is, in this embodiment, the developing unit 4 transfers toner charged to the same polarity as that of the photosensitive drum 1 (negative polarity in this embodiment) to a portion (image area) on the photosensitive drum 1 where the charge has been attenuated by exposure. , exposed areas) to develop an electrostatic image.

In this embodiment, the photosensitive drum 1, the charging roller 2, the developing unit 4, and the cleaning member 6 as process means acting on the photosensitive drum 1 are integrated, that is, integrally formed into a cartridge, and the process cartridge 7 is formed. The process cartridge 7 can be attached to and detached from the image forming apparatus 100 via attachment means such as an attachment guide and a positioning member provided in the image forming apparatus main body 100A. In this embodiment, the process cartridges 7 for each color all have the same shape, and the process cartridges 7 for each color include yellow (Y), magenta (M), cyan (C), and black ( K) toner of each color is stored.

The intermediate transfer belt 5, which is an endless belt and serves as an intermediate transfer body, contacts all the photosensitive drums 1 and circulates (rotates) in the direction of arrow B (counterclockwise) in the figure. The intermediate transfer belt 5 is stretched around a driving roller 51, a secondary transfer opposing roller 52, and a driven roller 53 as a plurality of supporting members. On the inner peripheral surface side of the intermediate transfer belt 5, four primary transfer rollers 8, which serve as primary transfer means, are arranged in parallel so as to face each photosensitive drum 1. The primary transfer roller 8 presses the intermediate transfer belt 5 toward the photosensitive drum 1 to form a primary transfer portion N1 where the intermediate transfer belt 5 and the photosensitive drum 1 are in contact with each other. Then, a bias having a polarity opposite to the normal charging polarity of the toner is applied to the primary transfer roller 8 from a primary transfer bias power source (high voltage power source) as a primary transfer bias applying means (not shown). As a result, the toner image on the photosensitive drum 1 is transferred onto the intermediate transfer belt 5 (primary transfer).

Further, a secondary transfer roller 9 as a secondary transfer means is arranged at a position facing the secondary transfer opposing roller 52 on the outer peripheral surface side of the intermediate transfer belt 5. The secondary transfer roller 9 is pressed against the secondary transfer opposing roller 52 via the intermediate transfer belt 5, and forms a secondary transfer portion N2 where the intermediate transfer belt 5 and the secondary transfer roller 9 are in contact with each other. Then, a bias having a polarity opposite to the normal charging polarity of the toner is applied to the secondary transfer roller 9 from a secondary transfer bias power source (high voltage power source) serving as a secondary transfer bias applying means (not shown). As a result, the toner image on the intermediate transfer belt 5 is transferred onto the recording material 12 (secondary transfer).

To explain further, when forming an image, first, the surface of the photosensitive drum 1 is uniformly charged by the charging roller 2. Next, the surface of the charged photoreceptor drum 1 is scanned and exposed to light according to the image information emitted from the scanner unit 3, and an electrostatic image according to the image information is formed on the photoreceptor drum 1. Next, the electrostatic image formed on the photoreceptor drum 1 is developed as a toner image by the developing unit 4. The toner image formed on the photosensitive drum 1 is transferred (primary transfer) onto the intermediate transfer belt 5 by the action of the primary transfer roller 8 .

For example, when forming a full-color image, the processes up to the primary transfer described above are sequentially performed in the first to fourth image forming sections SY, SM, SC, and SK, and toner images of each color are formed on the intermediate transfer belt 5. Next, they are superimposed and primary transferred. Thereafter, the recording material 12 is conveyed to the secondary transfer section N2 in synchronization with the movement of the intermediate transfer belt 5. The four-color toner images on the intermediate transfer belt 5 are secondarily transferred onto the recording material 12 all at once by the action of the secondary transfer roller 9 that is in contact with the intermediate transfer belt 5 via the recording material 12 . The recording material 12 onto which the toner image has been transferred is conveyed to a fixing device 10 as a fixing means. The toner image is fixed on the recording material 12 by applying heat and pressure to the recording material 12 in the fixing device 10 . The recording material 12 with the toner image fixed thereon is conveyed further downstream from the fixing device 10 and is discharged outside the apparatus.

The primary transfer residual toner remaining on the photosensitive drum 1 after the primary transfer process is removed and collected by the cleaning member 6. Further, secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer process is cleaned by an intermediate transfer belt cleaning device 11. Note that the image forming apparatus 100 can also form monochrome or multicolor images using only one desired image forming section or using only some (but not all) image forming sections. It looks like this.

<Schematic configuration of process cartridge>
Referring to FIG. 2, the overall configuration of the process cartridge 7 installed in the image forming apparatus 100 of this embodiment will be described. In this embodiment, the structure and operation of the process cartridges 7 for each color are substantially the same except for the type (color) of toner contained therein. FIG. 2 is a schematic cross-sectional (main cross-sectional) view of the process cartridge 7 of this embodiment as viewed along the longitudinal direction (rotation axis direction) of the photosensitive drum 1. As shown in FIG. The attitude of the process cartridge 7 in FIG. 2 is the attitude when it is installed in the main body of the image forming apparatus, and when the positional relationships and directions of each member of the process cartridge are described below, the positional relationships and directions in this attitude are used. etc. That is, the up-down direction of the page in FIG. 2 corresponds to the vertical direction, and the left-right direction of the page corresponds to the horizontal direction. Note that this layout configuration setting is based on the assumption that the image forming apparatus is installed on a horizontal surface as a normal installation state.

The process cartridge 7 is configured by integrating a photosensitive unit 13 including the photosensitive drum 1 and the like, and a developing unit 4 including the developing roller 17 and the like. The photoreceptor unit 13 has a cleaning frame 14 as a frame that supports various elements within the photoreceptor unit 13 . The photosensitive drum 1 is rotatably attached to the cleaning frame 14 via a bearing (not shown). The photosensitive drum 1 is rotationally driven in the direction of arrow A (clockwise) in the figure in accordance with the image forming operation by transmitting the driving force of a drive motor as a drive means (drive source) not shown to the photoconductor unit 13. Ru. In this embodiment, the photosensitive drum 1, which plays a central role in the image forming process, is an organic photosensitive drum 1 in which the outer circumferential surface of an aluminum cylinder is coated with a subbing layer, a carrier generation layer, and a carrier transport layer, which are functional films, in this order. I am using it.

Further, a cleaning member 6 and a charging roller 2 are arranged in the photosensitive unit 13 so as to be in contact with the circumferential surface of the photosensitive drum 1 . Transfer residual toner removed from the surface of the photosensitive drum 1 by the cleaning member 6 falls into the cleaning frame 14 and is accommodated therein. The charging roller 2, which is a charging means, is driven to rotate by bringing a conductive rubber roller portion into pressure contact with the photosensitive drum 1. Here, a predetermined DC voltage is applied to the core metal of the charging roller 2 with respect to the photosensitive drum 1 during the charging process, so that the surface of the photosensitive drum 1 has a uniform dark potential (Vd). is formed. The spot pattern of the laser light emitted according to the image data by the laser light from the scanner unit 3 described above exposes the photosensitive drum 1, and the exposed area is charged on the surface by carriers from the carrier generation layer. disappears and the potential decreases. As a result, an electrostatic latent image is formed on the photosensitive drum 1, with the exposed areas having a predetermined bright potential (Vl) and the unexposed areas having a predetermined dark potential (Vd). In this embodiment, Vd=-500V and Vl=-100V.

<Developing unit>
The developing unit 4 includes a developing roller 17 , a developing blade 21 , a toner supply roller 20 , and an agitation conveyance member 22 . The developing roller 17 supports toner 40 as a developer carrier. The developing blade 21 serves as a regulating member and regulates (the layer thickness of) the toner 40 carried on the developing roller 17 . The toner supply roller 20 serves as a developer supply member and supplies toner 40 to the developing roller 17 . The stirring and conveying member 22 serves as a conveying member and conveys the toner 40 to the toner supply roller 20 . The developing unit 4 includes a developing container 18 as a frame body in which a developing roller 17, a toner supply roller 20, and an agitating conveyance member 22 are rotatably assembled. The developer container 18 is configured to move the toner 40 between a toner storage chamber 18a in which the agitation conveyance member 22 is arranged, a development chamber 18b in which the development roller 17 and the toner supply roller 20 are arranged, and the toner storage chamber 18a and the development chamber 18b. and a communication port 18c that communicates with each other so as to enable communication with each other. The communication port 18c is provided in a partition wall portion 18d (18d1 to 18d3) that partitions the toner storage chamber 18a and the developing chamber 18b.

The partition wall portion 18d divides the internal space of the developing frame 18 (developing container) into a toner storage chamber 18a and a developing chamber 18b. The partition wall portion 18d is connected to a first wall portion 18d1 that partitions the internal space of the developing frame 18 above the communication port 18c, a second wall portion 18d2 that partitions the space below the communication port 18c, and a second wall portion 18d2 for supplying toner. It has a third wall portion 18d3 partitioning below the roller 20 and the developing roller 17. The first wall portion 18d1 and the second wall portion 18d2 extend in a direction inclined with respect to the vertical direction so that the opening direction of the communication port 18c from the toner storage chamber 18a to the developing chamber 18b faces upward rather than the horizontal direction. ing. The communication port 18c opens in a region of the partition wall portion 18d on the side opposite to the developing roller 17 with respect to the toner supply roller 20 so as to face a space above the toner supply roller 20 in the developing chamber 18b. . As a result, the internal space of the developing chamber 18b expands in the horizontal direction as it goes upward, and the communication port 18c is configured to easily receive the toner 40 that is pumped up by the agitation conveyance member 22 from the bottom of the toner storage chamber 18a upward. be done. The third wall portion 18d3 extends below the toner supply roller 20 and the developing roller 17 from the lower end of the second wall portion 18d2 in a substantially horizontal direction. The third wall portion 18d3, together with the second wall portion 18d2, is configured to receive toner 40 spilled from the toner supply roller 20 and the developing roller 17 among the toner 40 that has passed through the communication port 18c (a storage tank for toner 40). is formed. The configuration consisting of the second wall portion 18d2 and the third wall portion 18d3 extends from one side of the developing frame 18 to the other side in the longitudinal direction (direction along the rotational axis of the developing roller 17 or the toner supply roller 20). It is formed.

Here, the internal space of the developing chamber 18b is divided into a first space, a second space, and a third space. In FIG. 7, the first space is indicated by S1, the second space by S2, and the third space by S3.

The first space refers to the space above the nip portion N in the developing chamber 18b. More specifically, the first space refers to the inner space of the developing chamber 18b where the circumferential surfaces of the toner supply roller 20 and the developing roller 17 and the inner wall surface of the developing chamber 18b are mutually located above the nip portion N. These are opposing spatial areas. The first space includes a region above the nip portion N of the circumferential surfaces of the toner supply roller 20 and the developing roller 17, an inner wall surface of the developing chamber 18b facing these, and both longitudinal side surfaces of the developing chamber 18b. , surrounded by.

The second space refers to a space provided in the developing chamber 18b such that the space expands in the rotational downstream direction of the toner supply roller 20 with the narrow portion below the toner supply roller 20 as a boundary.

Here, the narrow portion refers to a portion where the distance between the third wall portion 18d3 of the wall portion 18d that partitions the internal space of the developing chamber 18b and the circumferential surface of the toner supply roller 20 is the narrowest in the opposing region.

Specifically, in the space where the circumferential surface of the toner supply roller 20 and the third wall portion 18d3 face each other, the second space expands toward the downstream side in the rotational direction of the toner supply roller 20 with the narrow portion as a boundary. This is a spatial region in which the distance between the peripheral surface and the third wall portion 18d3 gradually increases. The second space includes the third wall portion 18d3, the peripheral surface area of the toner supply roller 20 and the developing roller 17 facing the third wall portion 18d3, and the developing blade 21 on the downstream side of the narrow portion in the rotational direction of the toner supply roller 20. , and both longitudinal side surfaces of the developing chamber 18b.

The third space refers to a space provided inside the developing chamber 18b such that the space expands in the rotational upstream direction of the toner supply roller 20 with the narrow portion as a boundary. More specifically, in the space where the circumferential surface of the toner supply roller 20 and the third wall portion 18d3 face each other, the third space becomes closer to the circumferential surface of the toner supply roller 20 as it goes upstream in the rotational direction with the narrow portion as a boundary. This is a spatial region in which the distance from the third wall portion 18d3 gradually increases. The third space includes a second wall portion 18d2, a third wall portion 18d3, an area of the circumferential surface of the toner supply roller 20 facing these, and a developing chamber 18b, on the upstream side of the narrow portion in the rotational direction of the toner supply roller 20. surrounded by both longitudinal sides of.

In this embodiment, the second space is configured to be wider than the third space in the cross sections shown in FIGS. 2, 7, and the like.

The toner 40 pumped up by the agitation conveyance member 22 can overcome the toner supply roller 20 because the upper end of the communication port 18c (the border with the lower end of the first wall portion 18d1) is arranged above the upper end of the toner supply roller 20. and is supplied above the nip portion N (first space). The toner 40 supplied above the nip portion N (first space) is sucked into the inside of the toner supply roller 20 (inside the bubble cavities of the foam layer) by the deformation of the toner supply roller 20, and the toner supply roller 20 rotates. It moves counterclockwise in the figure and reaches the lower end of the nip portion N. Furthermore, a portion of the toner 40 that has been pumped up by the agitation conveyance member 22 and supplied to the surface of the toner supply roller 20 returns to the toner storage chamber 18a as the toner supply roller 20 rotates in the direction of arrow E. The remaining toner 40 is conveyed toward the region below the toner supply roller 20 (third space→second space).

When the toner supply roller 20 reaches the lower end of the nip N, the toner 40 is discharged from the inside of the toner supply roller 20 (inside the bubble cavities of the foam layer) due to the deformation of the toner supply roller 20, and is rubbed by the nip N while being applied to the developing roller 17. Supplied. The toner 40 adhering to the developing roller 17 is regulated and charged by the developing blade 21, and the toner 40 that has passed through the regulating portion forms a uniform toner coat on the developing roller 17. Further, the toner 40 remaining without being developed in the developing section is also strongly scraped off by the surfaces of the toner supply roller 20 and the developing roller 17 rotating in opposite directions at the nip section N. The toner 40 regulated by the developing blade 21 and separated from the developing roller 17 falls below the developing blade 21 (second space). Further, the toner 40 that is discharged from the inside of the toner supply roller 20 and does not adhere to the developing roller 17 is discharged below the nip portion N (second space).

When the above operations are repeated, the toner 40 is accumulated in the second space, forming a compacted state of the toner 40. When the compacted state is formed, the toner 40 is supplied to the surface or inside of the toner supply roller 20 from the compacted portion. Further, due to the formation of the compressed state, the toner 40 passes through the narrow portion and moves from the second space (the compressed space) to the third space. Due to the pressure of the flow of the toner 40, a part of the toner 40 climbs over the upper end of the second wall portion 18d2 below the communication port 18c and is returned to the toner storage chamber 18a.

With reference to FIG. 7, details of the arrangement of each member in the developing chamber 18b of this embodiment will be described. FIG. 7 is a schematic cross-sectional view illustrating the arrangement relationship of each member in the developing device according to this embodiment.

In this embodiment, (i) the upper end of the communication port 18c separating the developing chamber 18b and the toner storage chamber 18a (the boundary between the communication port 18c and the first wall portion 18d1) is relative to the upper end of the toner supply roller 20; It was placed above. That is, as shown in FIG. 7, the horizontal line h1 passing through the upper end of the communication port 18c is located above the horizontal line h2 passing through the upper end of the toner supply roller 20.

(ii) The center of the nip portion N (the central portion in the height direction, or the position intersecting the line connecting the rotation centers of the toner supply roller 20 and the developing roller 17) is located above the lower end of the communication opening 18c, and the nip portion N The lower end of is disposed above the lower end of the communication port 18c. That is, as shown in FIG. 7, the horizontal line h4 passing through the center of the nip portion N passes through the lower end of the communication port 18c (the upper end of the second wall portion 18d2 (the boundary with the communication port 18c in the second wall portion 18d2)). It is located above the horizontal line h6. Further, a horizontal line h5 passing through the lower end of the nip portion N is located above a horizontal line h6 passing through the lower end of the communication port 18c.

(iii) The lower end of the communication port 18c (the upper end of the second wall portion 18d2) is arranged above the end portion 21b on the upstream side in the rotational direction of the developing roller 17 at the contact position 21c between the developing blade 21 and the developing roller 17. . That is, as shown in FIG. 7, the horizontal line h6 passing through the lower end of the communication port 18c (the upper end of the second wall portion 18d2) is higher than the horizontal line h7 passing through the contact position 21c of the developing blade 21 with the developing roller 17. positioned.

(iv) The upper surface of the third wall portion 18d3 of the inner surface of the developing chamber 18b forming the second space and the third space was arranged as follows. First, a vertical line is drawn based on the end 21b (free end tip) located upstream in the rotational direction of the developing roller 17 from the contact position 21c of the developing blade 21 with the developing roller 17 (see FIG. 7). Then, the position of the intersection between the vertical line and the inner surface of the developing chamber 18b (the upper surface of the third wall portion 18d3) facing the second space is used as a reference point, and from a position horizontally away from the reference point with respect to the narrow portion. , so as to form a surface extending substantially horizontally toward the third space with the narrow portion interposed therebetween.

(v) The lower end of the communication port 18c is arranged above the lower end of the toner supply roller 20. That is, as shown in FIG. 7, the horizontal line h6 passing through the lower end of the communication port 18c (the upper end of the second wall portion 18d2) is located above the horizontal line h8 passing through the lower end of the toner supply roller 20.

The effects of the arrangement configurations (i) to (v) will be explained below.

(i) Arrangement relationship between the upper end of the communication port 18c and the upper end of the toner supply roller 20 As described above, the main toner supply to the toner supply roller 20 is when the toner 40 is drawn up by the stirring conveyance member 22 and 1 space). In this embodiment, since the upper end of the communication port 18c is disposed above the upper end of the toner supply roller 20, the toner supply roller 20 can be moved over the toner supply roller 20 and above the nip portion N (first space). Toner 40 can be supplied to the suction port. (Since the toner supply roller 20 is rotating in a counter direction with respect to the developing roller 17, it sucks the toner 40 above the nip portion N). When the upper end of the communication port 18c is disposed below the upper end of the toner supply roller 20, the upper end of the communication port 18c blocks the toner supply path, so that the agitation conveyance member 22 directly supplies the upper end of the nip portion N. It becomes difficult to supply toner to the space. Further, in such a case, the toner 40 supplied to the side surface of the toner supply roller 20 is returned toward the toner storage chamber 18a due to the rotation of the toner supply roller 20, and the toner 40 is not sufficiently supplied to the toner supply roller 20. In some cases, it may not be possible to supply toner properly.

(ii) Positional relationship between the center of the nip portion N (center in the height direction) and the lower end of the communication port 18c The lower end of the communication port 18c is above the center position of the nip portion N (height of the center in the height direction) In this case, the height of the toner agent surface accommodated in the second space and the third space in the developing chamber 18b exceeds the center of the nip portion N. In such an arrangement, the toner 40 easily enters the nip portion N, and the mechanical stripping force of the toner supply roller 20 against the toner 40 remaining on the developing roller 17 after the developing operation becomes weak, resulting in insufficient stripping. Image defects such as "development streaks" are more likely to occur. Therefore, the lower end of the communication port 18c needs to be located at least lower than the upper end of the nip portion N. That is, as shown in FIG. 7, the horizontal line h6 passing through the lower end of the communication port 18c is located below the horizontal line h3 passing through the upper end of the nip portion N. Furthermore, it is desirable to arrange the lower end of the communication port 18c below the center position of the nip portion N, since this can improve the stripping performance of the toner supply roller 20. Furthermore, it is more desirable that the lower end of the communication port 18c be disposed below the lower end of the nip portion N, since this can further improve the stripping performance of the toner supply roller 20. That is, as shown in FIG. 7, it is desirable that the horizontal line h6 passing through the lower end of the communication port 18c is located below the horizontal line h5 passing through the lower end of the nip portion N.

(iii) Positional relationship between the lower end of the communication port 18c and the tip of the developing blade 21 The lower end of the communication port 18c is connected to the end 21b on the upstream side in the rotational direction of the developing roller 17 at the contact position 21c between the developing blade 21 and the developing roller 17. be placed at the same position or above. In this way, the excess toner 40 regulated by the developing blade 21 is continuously supplied to the second space. By doing this, the density of the toner 40 in the second space is further increased, and the toner is supplied from the second space to the toner supply roller 20 and from the third space by climbing over the wall at the lower end of the communication port 18c. A flow of the toner 40 returning to the toner storage chamber 18a can be formed. While satisfying other structural requirements of this embodiment, the lower end of the communication port 18c is located below the end 21b of the developing blade 21 on the upstream side in the rotational direction of the developing roller 17 than the contact position 21c with the developing roller 17. , it was difficult to increase the degree of consolidation of the second space.

(iv) Arrangement relationship between the angle between the tip of the developing blade 21 and the inner wall of the developing container In order for the toner 40 to move from the second space to the third space, the second It is necessary to appropriately set the angle between the space and the inner surface of the wall of the developing frame 18 (the upper surface of the third wall 30c) facing the third space. Therefore, in this embodiment, from a position horizontally farther from the narrow portion than the intersection of the above-mentioned vertical line (see FIG. 7) and the inner surface of the wall portion of the developing frame 18 (the upper surface of the third wall portion 18d3). The inner surface of the wall portion of the developing frame 18 is configured to be approximately horizontal. By doing this, the toner 40 that falls into the second space after being supplied from the toner supply roller 20 to the developing roller 17 and regulated by the developing blade 21 moves toward the third space with the narrow portion sandwiched therebetween. It becomes easier to do.

Note that, in order to make it easier for the toner to move from the second space toward the third space, the toner descends from the second space toward the third space (the upper surface of the third wall portion 18d3 is sloped). It may be configured as follows. By doing so, toner circulation from the second space to the third space can be further promoted.

(v) Positional relationship between the lower end of the communication port 18c and the toner supply roller 20 In the configuration of this embodiment, the lower end of the communication port 18c is arranged above the lower end of the toner supply roller 20. By doing so, the amount of toner returning from the third space to the toner storage chamber 18a can be controlled to an appropriate amount, thereby making it possible to form an appropriately compressed space in the second space.

The developing chamber 18b is provided with a developing opening for transporting the toner 40 to the outside of the developing container 18, and the developing roller 17 is rotatably assembled to the developing container 18 so as to close the developing opening. There is. That is, the toner 40 contained in the developer container 18 is carried and conveyed by the rotating developer roller 17, passes through the developer opening, moves to the outside of the developer container 18, and develops the electrostatic latent image on the photosensitive drum 1. It will be offered to At this time, the amount of toner carried out to the outside of the developer container 18 is regulated and adjusted by the developer blade 21. The toner storage chamber 18a is located below the developing chamber 18b in the direction of gravity. The position where the developing blade 21 contacts the developing roller 17 is located below the rotational center of the developing roller 17 and between the rotational center of the developing roller 17 and the rotational center of the toner supply roller 20 in the horizontal direction.

The toner supply roller 20 and the developing roller 17 rotate in a direction in which their respective surfaces move from the lower end of the nip portion N to the upper end. That is, the toner supply roller 20 is rotating in the direction of arrow E (counterclockwise) in the figure, and the developing roller 17 is rotating in the direction of arrow D (counterclockwise). The toner supply roller 20 and the developing roller 17 are in contact with each other with a predetermined amount of penetration.

The toner supply roller 20 and the developing roller 17 rotate in the same direction with a difference in peripheral speed in the nip portion N, and through this operation, the toner supply roller 20 supplies toner to the developing roller 17. . At this time, the amount of toner supplied to the developing roller can be adjusted by adjusting the potential difference between the toner supply roller and the developing roller.

In this embodiment, the toner supply roller 20 is driven to rotate at a rotation speed of 700 rpm, and the developing roller 17 is driven to rotate at a rotation speed of 700 rpm. is applying V=-400V. This makes it easy to electrically supply toner from the toner supply roller 20 to the developing roller 17. In this embodiment, the developing roller 17 and the toner supply roller 20 both have an outer diameter of 15 mm, and the amount of penetration of the toner supply roller 20 into the development roller 17 is determined by the amount of penetration of the toner supply roller 20 into the development roller 17. The amount of dent is set to 1.0 mm.

The stirring and conveying member 22 stirs the toner 40 contained in the toner storage chamber 18a, and conveys the toner 40 in the direction of arrow G in the figure toward the upper part of the toner supply roller 20 in the developing chamber 18b. In this embodiment, the stirring and conveying member 22 is driven to rotate at a rotational speed of 130 rpm. The developing roller 17 and the photosensitive drum 1 rotate so that their respective surfaces move in the same direction (in the present embodiment, from the bottom to the top) at opposing portions. In this embodiment, the developing roller 17 is placed in contact with the photosensitive drum 1, but the developing roller 17 may be placed close to the photosensitive drum 1 at a predetermined distance. good.

In this example, a roller coated with an elastic rubber layer (elastic layer 1702) was used as the developing roller 17. In order to maintain uniform contact with the photosensitive drum 1, the elastic rubber layer preferably has a hardness of 20 to 50 degrees in MD1 hardness. If the hardness is less than 20°, it becomes difficult to polish the surface and it becomes difficult to obtain a desired roller surface shape. When the hardness is greater than 50°, the contact force of the developing roller 17 against the photosensitive drum 1 becomes high, and the toner is likely to be crushed due to pressure contact. In the examples, a rubber hardness of 38° was used. Rubber hardness was measured using an MD-1 hardness meter (needle shape: Type A) manufactured by Kobunshi Keiki Co., Ltd.

The surface roughness is set to a centerline average roughness Ra of 0.2 to 2 [μm], and the required amount of toner is retained on the surface. When Ra is less than 0.2, the desired amount of toner cannot be obtained and the density becomes low. Furthermore, when Ra is greater than 2, it is difficult to sufficiently charge each toner, and so-called "fogging", in which toner adheres to non-image areas, tends to occur. In the example, one with Ra=1.0 μm was used. The center line average roughness Ra was measured using "Surfcorder SE3500" manufactured by Kosaka Institute.

In this embodiment, in response to a predetermined DC bias applied to the developing roller 17, the toner 40 negatively charged due to frictional charging is applied to the bright area potential area from the potential difference in the developing area in contact with the photosensitive drum 1. The electrostatic latent image is transferred only to the electrostatic latent image. In this embodiment, by applying V=-300V to the developing roller 17, a potential difference ΔV=200V with the bright area potential portion is formed, and a toner image is formed.

Referring to FIG. 3, the toner seal structure of the developing unit 4 in this embodiment will be described. FIG. 3 is a schematic cross-sectional view showing the configuration of the developing unit 4 around the end of the developing roller 17 in the rotation axis direction (longitudinal direction). In the gap between the back surface of the developing blade 21 and the circumferential surface of the developing roller 17 in the developing unit 4, a flexible end sealing member 80 whose surface that rubs against the developing roller 17 is formed of felt, pile fabric, or the like is provided. are placed and sealed. The end sealing member 80 fills a gap between the developing roller 17, the developing unit 4, and the back surface of the developing blade 21 (the surface opposite to the contact surface of the developing roller 17). By pressing the end seal member 80 against the circumferential surface of the developing roller and the back surface of the developing blade, toner is prevented from leaking in the longitudinal direction.

<Configuration of developing blade>
Next, the developing blade 21 (regulating member), which is a feature of the present invention, will be explained.

In this embodiment, as shown in FIG. 4, the developing blade 21 is arranged so as to face in a counter direction with respect to the rotation of the developing roller 17, and is a member that regulates the amount of toner carried on the developing roller 17. be.

Further, the toner 40 is triboelectrically charged by the sliding friction between the developing blade 21 and the developing roller 17, and at the same time, the layer thickness is regulated.

One end 21a of the developing blade 21 in the transverse direction (D11) perpendicular to the longitudinal direction is fixed to the developing container 18 with a fastener such as a screw, and the other end 21b is a free end. The direction (D11) in which the developing blade 21 extends from one end 21a fixed to the developing container 18 to the other end 21b contacting the developing roller 17 is the rotational direction of the developing roller 17 at the portion (2102) where the developing blade 21 contacts the developing roller 17. The direction is opposite to (D) (counter direction).

In this embodiment, the developing blade 21 is a thin plate of SUS304-1/2H having a free length in the lateral direction of 8 mm and a thickness of 0.07 mm or more and 0.10 mm or less and having leaf spring-like elasticity. Here, the developing blade 21 is not limited to this, and may be a thin metal plate made of phosphor bronze, aluminum, or the like.

The free end (21b) side of the developing blade 21 is brought into contact with the surface of the developing roller 17 with a pressing force such that the linear pressure is 20 to 40 [N/m]. As shown in FIG. 4, the developing blade 21 includes a linear portion 211a that extends linearly. The free end side of the straight portion 211a is bent into an arc shape with a predetermined radius of curvature R (Rb) from the bending start position P1 toward the tip 21b (a bent portion 2102 is formed).

Further, as shown in FIG. 4, the developing blade 21 has a distance H (including the blade thickness, hereinafter referred to as height H) in the vertical direction (direction perpendicular to D11) from the linear portion 211a extending linearly to the tip 21b. It has a bending angle θ [°] (angle between directions D11 and D12).

When the height H of the developing blade 21 is lower than 0.15 mm, it is necessary to cut the tip after bending the thin plate in order to ensure a bending allowance. This is undesirable as it is costly.

Furthermore, if the height H is set higher than 0.5 mm, the gap between the developing unit 4, the developing blade 21, and the circumferential surface of the developing roller 17 cannot be completely filled with the end sealing member 80, and toner leaks in the longitudinal direction. may occur. Therefore, in this example, the height H is 0.15 [mm]≦H≦0.5 [mm], and the bending angle (angle between direction D11 and direction D12) is A developing blade 21 satisfying 80≦θ≦130 was used.

The ridgeline 2101 of the bent portion 2012 of the developing blade 21 extends from the front to the back perpendicular to the paper surface of FIG. is in contact with the surface.

A predetermined voltage is applied to the developing blade 21 from a blade bias power source (not shown) to stabilize the toner coating, and V=-500V is applied as the blade bias.

<Toner>
<About the surface layer containing organosilicon polymer>
When the toner particles have a surface layer containing an organosilicon polymer, they preferably have a partial structure represented by formula (1).
R-SiO _3/2 formula (1)
(R represents a hydrocarbon group having 1 to 6 carbon atoms.)

In the organosilicon polymer having the structure of formula (1), one of the four valences of Si atoms is bonded to R, and the remaining three are bonded to O atoms. Two valences of O atoms are both bonded to Si, that is, form a siloxane bond (Si--O--Si). Considering Si atoms and O atoms as an organosilicon polymer, there are 2 Si atoms and 3 O atoms, so it is expressed as -SiO _3/2 . It is thought that the -SiO _3/2 structure of this organosilicon polymer has properties similar to those of silica (SiO ₂ ) composed of a large number of siloxane bonds. Therefore, it is thought that it is possible to increase the Martens hardness because the toner has a structure closer to an inorganic material than a conventional toner whose surface layer is formed of an organic resin.

In the partial structure represented by formula (1), R is preferably a hydrocarbon group having 1 or more and 6 or less carbon atoms. This makes it easier to stabilize the amount of charge. Particularly preferred is an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a phenyl group, which has excellent environmental stability.

In the present invention, it is more preferable that R is a hydrocarbon group having 1 or more and 3 or less carbon atoms in order to further improve chargeability. When the charging property is good, the transfer property is good and there is little toner remaining after transfer, so that the drum, charging member, and transfer member are less likely to be contaminated.

Preferred examples of the hydrocarbon group having 1 to 3 carbon atoms include a methyl group, an ethyl group, a propyl group, and a vinyl group. From the viewpoint of environmental stability and storage stability, R is more preferably a methyl group.

As an example of producing the organosilicon polymer, a sol-gel method is preferable. The sol-gel method is a method in which a liquid raw material is used as a starting material and subjected to hydrolysis and condensation polymerization to form a gel through a sol state, and is used in a method for synthesizing glass, ceramics, organic-inorganic hybrids, and nanocomposites. Using this production method, functional materials in various shapes such as surface layers, fibers, bulk bodies, and fine particles can be produced from a liquid phase at low temperatures.

Specifically, the organosilicon polymer present in the surface layer of the toner particles is preferably produced by hydrolysis and polycondensation of a silicon compound typified by alkoxysilane.

By providing a surface layer containing this organosilicon polymer on toner particles, environmental stability is improved, toner performance is less likely to deteriorate during long-term use, and a toner with excellent storage stability can be obtained. .

Furthermore, since the sol-gel method starts from a liquid and forms a material by gelling the liquid, it is possible to create various fine structures and shapes. Particularly, when toner particles are produced in an aqueous medium, the hydrophilic properties of hydrophilic groups such as silanol groups of organosilicon compounds facilitate precipitation on the surfaces of the toner particles. The above-mentioned fine structure and shape can be adjusted by adjusting the reaction temperature, reaction time, reaction solvent, pH, type and amount of the organometallic compound, etc.

The organosilicon polymer in the surface layer of the toner particles is preferably a condensation product of an organosilicon compound having a structure represented by the following formula (Z).

(In formula (Z), R ₁ represents a hydrocarbon group having 1 to 6 carbon atoms, and R ₂ , R ₃ and R ₄ are each independently a halogen atom, a hydroxy group, an acetoxy group, or (Represents an alkoxy group.)

Hydrophobicity can be improved by the hydrocarbon group (preferably an alkyl group) of _R1 , and toner particles with excellent environmental stability can be obtained. Moreover, an aryl group which is an aromatic hydrocarbon group, such as a phenyl group, can also be used as the hydrocarbon group. When the hydrophobicity of R ₁ is large, the charge amount tends to fluctuate greatly in various environments, so in view of environmental stability, R ₁ is preferably a hydrocarbon group having 1 or more and 3 or less carbon atoms, More preferably, it is a methyl group.

R ₂ , R ₃ and R ₄ are each independently a halogen atom, a hydroxy group, an acetoxy group, or an alkoxy group (hereinafter also referred to as a reactive group). These reactive groups undergo hydrolysis, addition polymerization, and condensation polymerization to form a crosslinked structure, making it possible to obtain a toner with excellent member stain resistance and development durability. From the viewpoint of mild hydrolyzability at room temperature and precipitation and coating properties on the surface of toner particles, an alkoxy group having 1 to 3 carbon atoms is preferable, and a methoxy group or an ethoxy group is more preferable. . Moreover, the hydrolysis, addition polymerization, and condensation polymerization of R ₂ , R ₃ , and R ₄ can be controlled by the reaction temperature, reaction time, reaction solvent, and pH.

In order to obtain the organosilicon polymer used in the present invention, an organosilicon compound having three reactive groups (R ₂ , R ₃ and R ₄ ) in one molecule excluding R ₁ in the formula (Z) shown above is used. (hereinafter also referred to as trifunctional silane) may be used singly or in combination.

Further, the content of the organosilicon polymer in the toner particles is preferably 0.5% by mass or more and 10.5% by mass or less.

When the content of the organosilicon polymer is 0.5% by mass or more, the surface free energy of the surface layer can be further reduced, fluidity is improved, and member contamination and fogging can be suppressed. . When the content is 10.5% by mass or less, charge-up can be made difficult to occur. The content of the organosilicon polymer should be controlled by the type and amount of the organosilicon compound used to form the organosilicon polymer, the method for producing toner particles during the formation of the organosilicon polymer, reaction temperature, reaction time, reaction solvent, and pH. I can do it.

It is preferable that the surface layer containing the organosilicon polymer and the toner core particles are in contact with each other without any gaps. This suppresses the occurrence of bleeding due to resin components, release agents, etc. in the interior of the toner particles rather than in the surface layer, and it is possible to obtain a toner with excellent storage stability, environmental stability, and development durability. In addition to the above organosilicon polymer, the surface layer may contain resins such as styrene-acrylic copolymer resin, polyester resin, and urethane resin, and various additives.

The toner particles contain a binder resin. The binder resin is not particularly limited, and conventionally known binder resins can be used. Vinyl resins, polyester resins, etc. are preferred.

<Method for manufacturing toner particles>
Known means can be used for manufacturing the toner particles, and a kneading and pulverizing method or a wet manufacturing method can be used. From the viewpoint of particle size uniformity and shape controllability, a wet manufacturing method can be preferably used. Furthermore, wet manufacturing methods include suspension polymerization, dissolution suspension, emulsion polymerization aggregation, emulsion aggregation, and the like.

Here, the suspension polymerization method will be explained. In the suspension polymerization method, first, polymerizable monomers for producing a binder resin and other additives such as colorants as necessary are mixed using a dispersion machine such as a ball mill or an ultrasonic dispersion machine. A polymerizable monomer composition in which the monomers are uniformly dissolved or dispersed is prepared (step). That is, it is a "preparation process of a polymerizable monomer composition". At this time, a polyfunctional monomer, a chain transfer agent, a wax as a mold release agent, a charge control agent, a plasticizer, etc. can be added as appropriate.

Next, the above polymerizable monomer composition is poured into an aqueous medium prepared in advance, and a desired droplet of the polymerizable monomer composition is dispersed using a stirrer or a disperser with high shear force. (granulation process).

It is preferable that the aqueous medium in the granulation step contains a dispersion stabilizer in order to control the particle size of toner particles, sharpen the particle size distribution, and suppress coalescence of toner particles during the manufacturing process.

Dispersion stabilizers are generally classified into polymers that exhibit repulsion due to steric hindrance and poorly water-soluble inorganic compounds that stabilize dispersion using electrostatic repulsion. Fine particles of poorly water-soluble inorganic compounds are preferably used because they are dissolved by acids or alkalis and can be dissolved and easily removed by washing with acids or alkalis after polymerization.

After the granulation step or while performing the granulation step, the polymerizable monomer contained in the polymerizable monomer composition is polymerized by setting the temperature preferably to 50° C. or higher and 90° C. or lower to form the toner. Obtain a particle dispersion (polymerization step).

In the polymerization step, it is preferable to perform a stirring operation so that the temperature distribution within the container becomes uniform. When adding a polymerization initiator, it can be added at any desired timing and time. In addition, the temperature may be raised during the latter half of the polymerization reaction in order to obtain a desired molecular weight distribution, and the temperature may be increased during the latter half of the reaction or at the end of the reaction in order to remove unreacted polymerizable monomers, by-products, etc. from the system. Afterwards, part of the aqueous medium may be distilled off. The distillation operation can be carried out under normal pressure or reduced pressure.

The weight average particle size of the toner particles is preferably 3.0 μm or more and 10.0 μm or less from the viewpoint of obtaining a high-definition and high-resolution image. The weight average particle size of the toner can be measured by a pore electrical resistance method. For example, it can be measured using "Coulter Counter Multisizer 3" (manufactured by Beckman Coulter, Inc.). The toner particle dispersion thus obtained is sent to a filtration step for solid-liquid separation of toner particles and an aqueous medium.

Solid-liquid separation to obtain toner particles from the obtained toner particle dispersion can be performed by a general filtration method, and then reslurry or washing water is used to remove foreign substances that could not be removed from the toner particle surface. It is preferable to perform further cleaning by spraying or the like. After sufficient washing, solid-liquid separation is performed again to obtain a toner cake. Thereafter, the toner particles are dried by a known drying means, and if necessary, particles having a particle size outside a predetermined size are separated by classification to obtain toner particles. At this time, the separated particle group having an unspecified particle size may be reused to improve the final yield.

When forming a surface layer containing an organosilicon polymer, when toner particles are formed in an aqueous medium, a hydrolyzed solution of an organosilicon compound is added as described above while performing a polymerization process in an aqueous medium. The surface layer can be formed. A dispersion of toner particles after polymerization may be used as a core particle dispersion, and a hydrolyzed solution of an organosilicon compound may be added to form the surface layer. In addition, when using a medium other than an aqueous medium such as a kneading and pulverizing method, the obtained toner particles are dispersed in an aqueous medium and used as a core particle dispersion liquid, and a hydrolyzed liquid of an organosilicon compound is added as described above, and the surface layer is can be formed.

<Measurement method of Martens hardness>
Hardness is one of the mechanical properties of the surface or near the surface of an object, and is the resistance of an object to deformation or damage when it is deformed or damaged by a foreign object. There are various measurement methods and definitions. For example, measurement methods are often used depending on the width of the measurement area, such as the Vickers method when the measurement area is 10μm or more, the nanoindentation method when it is 10μm or less, and AFM when it is 1μm or less. . Definitions include, for example, Brinell hardness and Vickers hardness for indentation hardness, Martens hardness for scratch hardness, and Shore hardness for rebound hardness.

When measuring toner, the nanoindentation method is a preferred measurement method because the typical particle size is 3 μm to 10 μm. According to studies conducted by the inventors, Martens hardness, which represents scratch hardness, is appropriate as a definition of hardness for achieving the effects of the present invention. This is believed to be because the scratch hardness can represent the resistance of the toner to being scratched by hard substances such as metals and external additives inside the developing machine.

The method of measuring the Martens hardness of toner using the nanoindentation method is to use a commercially available ISO 14577-1 compliant device and calculate it from the obtained load-displacement curve according to the indentation test procedure specified in ISO 14577-1. be able to. In the present invention, an ultra-micro indentation hardness tester "ENT-1100b" (manufactured by Elionix Co., Ltd.) was used as a device compliant with the ISO standard. The measurement method is described in the "ENT1100 Operation Manual" attached to the device, and the specific measurement method is as follows.

The measurement environment was maintained at 30.0°C inside the shield case using the attached temperature controller. Keeping the ambient temperature constant is effective in reducing variations in measurement data due to thermal expansion, drift, etc. The set temperature was set at 30.0° C., assuming the temperature near the developing machine where the toner is rubbed. We used the standard sample stand that comes with the device, and after applying the toner, we blown a weak air stream to disperse the toner, and then we set the sample stand in the device and held it there for over an hour before taking measurements. .

The measurement was carried out using a flat indenter (titanium indenter, tip made of diamond) with a flat tip of 20 μm square, which is attached to the device. For small-diameter, spherical objects such as toner, objects to which external additives are attached, and objects with uneven surfaces, a flat indenter is used because the use of a sharp indenter has a large effect on measurement accuracy. The maximum load of the test was set at 2.0×10 ⁻⁴ N. By setting this test load, it is possible to measure the hardness without destroying the surface layer of the toner under conditions equivalent to the stress that one toner particle receives in the developing section. In the present invention, since abrasion resistance is important, it is important to measure the hardness while maintaining the surface layer without destroying it.

As the particles to be measured, particles in which toner was present alone on a measurement screen (field size: 160 μm in width and 120 μm in height) using a microscope attached to the apparatus were selected. However, in order to eliminate errors in displacement as much as possible, particles whose diameter (D) was within the range of ±0.5 μm of the number average particle diameter (D1) (D1-0.5 μm≦D≦D1+0.5 μm) were selected. . The particle diameter of the particles to be measured was measured by measuring the major axis and minor axis of the toner using software attached to the apparatus, and the particle diameter D (μm) was defined as [(major axis + minor axis)/2]. In addition, the number average particle diameter was measured using a Coulter Counter Multisizer 3 (manufactured by Beckman Coulter, Inc.) according to the method described below.

In the measurement, 100 toner particles having a particle diameter D (μm) satisfying the above conditions were selected and measured. The conditions to be input during measurement are as follows.
Test mode: Load-unload test Test load: 20.000 mgf (=2.0 x 10 ^-4 N)
Number of divisions: 1000 steps
Step interval: 10msec
When the analysis menu "Data analysis (ISO)" is selected and measurement is performed, the Martens hardness is analyzed using the software attached to the device after the measurement and is output. The above measurements were performed on 100 toner particles, and the arithmetic average value thereof was defined as the Martens hardness in the present invention.

By adjusting the Martens hardness to 200 MPa or more and 1100 MPa or less when measured under the condition of a maximum load of 2.0 × 10 ^-4 N, the wear resistance of the toner in the developing area is significantly improved compared to conventional toners. It became possible. This has made it possible to increase the degree of freedom in process design for high-speed, high-quality images.

In other words, the range of options is widened, such as increasing the width of the regulating blade nip, increasing the rotation speed of the developing roller, and increasing the carrier mixing and agitation speed. As a result, it was possible to maintain the amount of charge while suppressing "development streaks" caused by material abrasion. Therefore, it was possible to suppress the occurrence of density unevenness.

When the Martens hardness is lower than 200 MPa, the toner cannot withstand the shear of the developing blade as a charge imparting member, the amount of charge of the toner decreases, and density unevenness and drop-off due to potential unevenness occur. A preferable value of the Martens hardness is 250 MPa or more, and a more preferable value is 300 MPa or more.

On the other hand, when the Martens hardness was higher than 1100 MPa, the developing blade and the developing roller were damaged, and "developing streaks" were generated. A preferable value of the Martens hardness is 1000 MPa or less, and a more preferable value is 900 MPa or less.

The means for adjusting the Martens hardness to 200 MPa or more and 1100 MPa or less when measured under the condition of a maximum load of 2.0×10 ⁻⁴ N is not particularly limited. However, since this hardness is significantly higher than that of organic resins used in general toners, it is difficult to achieve this by the means normally used to increase hardness. For example, this is difficult to achieve by designing a resin with a high glass transition temperature, increasing the resin molecular weight, thermosetting, adding filler to the surface layer, etc.

The Martens hardness of organic resins used in general toners is approximately 50 MPa to 80 MPa when measured under a maximum load of 2.0×10 ⁻⁴ N. Furthermore, even if the hardness is increased by increasing the resin design or molecular weight, the hardness is about 120 MPa or less. Further, even when a filler such as a magnetic material or a silicon compound is filled near the surface layer and thermally cured, the toner of the present invention is significantly harder than a general toner, with a strength of about 185 MPa at most.

<Hardness control method>
One way to adjust the hardness to the above specific range is to form the surface layer of the toner with a substance such as an inorganic material that has an appropriate hardness, and then control its chemical structure and macrostructure to have an appropriate hardness. One method is to do so.

As a specific example, an organosilicon polymer can be mentioned as a substance that can have the above-mentioned specific hardness, and the selection of the material depends on the number of carbon atoms directly bonded to the silicon atoms of the organosilicon polymer, the carbon chain length, etc. It is possible to adjust the hardness by

The toner particles have a surface layer containing an organosilicon polymer. The number of carbon atoms directly bonded to the silicon atoms of the organosilicon polymer is on average 1 to 3 (preferably 1 to 2, more preferably 1) per silicon atom. If it exists, it is preferable because the hardness can be easily adjusted to the specific hardness.

The Martens hardness can be adjusted by adjusting the chemical structure, such as crosslinking of the surface material and the degree of polymerization. The Martens hardness can be adjusted by adjusting the macrostructure by adjusting the uneven shape of the surface layer or the network structure connecting the protrusions. When an organosilicon polymer is used as the surface layer, these adjustments can be made by adjusting the pH, concentration, temperature, time, etc. during pretreatment of the organosilicon polymer. Further, it can be adjusted by adjusting the timing, form, concentration, reaction temperature, etc. of applying the organosilicon polymer to the surface layer of the core particles of the toner.

Particularly preferred in the present invention is the following method. First, toner core particles containing a binder resin are produced and dispersed in an aqueous medium to obtain a core particle dispersion. The concentration at this time is preferably such that the solid content of the core particles is 10% by mass or more and 40% by mass or less based on the total amount of the core particle dispersion. The temperature of the core particle dispersion liquid is preferably adjusted to 35° C. or higher. Further, the pH of the core particle dispersion is preferably adjusted to a pH at which condensation of the organosilicon compound does not proceed easily. Since the pH at which condensation of the organosilicon polymer is difficult to proceed varies depending on the substance, it is preferably within ±0.5 around the pH at which the reaction is least likely to proceed.

On the other hand, it is preferable to use a hydrolyzed organosilicon compound. For example, as a pretreatment for organosilicon compounds, they are hydrolyzed in a separate container. When the amount of organosilicon compound is 100 parts by mass, the concentration for hydrolysis is preferably 40 parts by mass or more and 500 parts by mass or less of water from which ions have been removed, such as ion-exchanged water or RO water, and more preferably 100 parts by mass of water. The amount is 400 parts by mass or less. The conditions for hydrolysis are preferably a pH of 2 to 7, a temperature of 15 to 80°C, and a time of 30 to 600 minutes.

By mixing the obtained hydrolysis liquid and the core particle dispersion and adjusting the pH to a value suitable for condensation (preferably 6 to 12, or 1 to 3, more preferably 8 to 12), the organosilicon compound can be dissolved. A surface layer can be applied to the surface of the toner core particles while condensing. It is preferable that the condensation and surface layering be carried out at 35° C. or higher for 60 minutes or longer. In addition, the surface macrostructure can be adjusted by adjusting the holding time at 35°C or higher before adjusting the pH to the appropriate pH for condensation, but in order to make it easier to obtain a specific Martens hardness, The following are preferred.

By the above-mentioned means, it is possible to reduce the number of reactive residues, form unevenness on the surface layer, and further form a network structure between the convexities, so that it is easy to obtain a toner having the above-mentioned specific Martens hardness. . When using a surface layer containing an organosilicon polymer, it is preferable that the adhesion rate of the organosilicon polymer is 90% or more and 100% or less. More preferably, it is 95% or more and 100% or less. A method for measuring the adhesion rate of the organosilicon polymer will be described later.

<Method for measuring the fixation rate of organosilicon polymer>
160 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) was added to 100 mL of ion-exchanged water and dissolved in a hot water bath to prepare a sucrose concentrate. Add 31 g of the above sucrose concentrate to a centrifugation tube (capacity 50 ml) and add 10 g of Contaminon N (a neutral detergent for cleaning precision measuring instruments with a pH of 7 consisting of a nonionic surfactant, an anionic surfactant, and an organic builder). A dispersion liquid was prepared by adding 6 mL of a mass% aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.). 1.0 g of toner was added to this dispersion, and the toner clumps were loosened using a spatula or the like.

The centrifugation tube was shaken in a shaker at 350 spm (strokes per min) for 20 minutes. After shaking, the solution was transferred to a swing rotor glass tube (volume 50 mL) and separated using a centrifuge (H-9R manufactured by Kokusan Co., Ltd.) at 3500 rpm for 30 minutes. It was visually confirmed that the toner and the aqueous solution were sufficiently separated, and the toner separated into the uppermost layer was collected with a spatula or the like. The aqueous solution containing the collected toner was filtered using a vacuum filter, and then dried in a drier for over 1 hour. The dried product was crushed with a spatula, and the amount of silicon was measured using fluorescent X-rays. The adhesion rate (%) was calculated from the ratio of the amount of elements to be measured in the toner after washing with water and the initial toner.

The measurement of fluorescent X-rays of each element is in accordance with JIS K 0119-1969, and specifically as follows.

The measurement equipment is a wavelength dispersive X-ray fluorescence spectrometer "Axios" (manufactured by PANalytical) and the attached dedicated software "SuperQ ver. 4.0F" (manufactured by PANalytical) for setting measurement conditions and analyzing measurement data. ) was used. Note that Rh was used as the anode of the X-ray tube, the measurement atmosphere was vacuum, the measurement diameter (collimator mask diameter) was 10 mm, and the measurement time was 10 seconds. Further, when measuring light elements, detection was performed using a proportional counter (PC), and when measuring heavy elements, detection was performed using a scintillation counter (SC).

As a measurement sample, approximately 1 g of washed toner and initial toner were placed in a special press aluminum ring with a diameter of 10 mm and flattened. Then, using a tablet molding and compressing machine "BRE-32" (manufactured by Maekawa Test Instruments Seisakusho Co., Ltd.), the pellets were pressurized at 20 MPa for 60 seconds and molded to a thickness of about 2 mm.

Measurements were performed under the above conditions, and the element was identified based on the peak position of the obtained X-rays, and its concentration was calculated from the counting rate (unit: cps), which is the number of X-ray photons per unit time.

To determine the amount of silicon in the toner, for example, 0.5 parts by mass of silica (SiO ₂ ) fine powder is added to 100 parts by mass of toner particles, and the mixture is thoroughly mixed using a coffee grinder. did. Similarly, silica fine powder was mixed with toner particles in amounts of 2.0 parts by mass and 5.0 parts by mass, respectively, and these were used as samples for a calibration curve.

For each sample, a sample pellet for the calibration curve was prepared as described above using a tablet molding and compressing machine, and when PET was used as a spectroscopic crystal, a diffraction angle (2θ) of 109.08° was observed. The counting rate (unit: cps) of Si-Kα rays was measured. At this time, the accelerating voltage and current value of the X-ray generator were 24 kV and 100 mA, respectively. A linear function calibration curve was obtained with the obtained X-ray count rate as the vertical axis and the amount of SiO ₂ added in each calibration curve sample as the horizontal axis.

Next, the toner to be analyzed was made into pellets using a tablet forming and compressing machine as described above, and the count rate of the Si-Kα rays was measured. Then, the content of the organosilicon polymer in the toner was determined from the above calibration curve. The ratio of the elemental amount of the toner after washing with water to the initial elemental amount of the toner calculated by the above method was determined and defined as the fixation rate (%).

<Toner>
FIG. 5 shows a schematic diagram of the toner 40 used in this example. In this embodiment, toner particles having a surface layer 40b containing an organosilicon polymer as the base particle 40a are used.

Hereinafter, all "parts" of each material are based on mass unless otherwise specified.

(Preparation process of aqueous medium 1)
14.0 parts of sodium phosphate (dodecahydrate, manufactured by Rasa Kogyo Co., Ltd.) was added to 1000.0 parts of ion-exchanged water in a reaction vessel, and the mixture was kept at 65° C. for 1.0 hour while purging with nitrogen.

T. K. Using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), a calcium chloride aqueous solution prepared by dissolving 9.2 parts of calcium chloride (dihydrate) in 10.0 parts of ion-exchanged water was added all at once while stirring at 12,000 rpm. to prepare an aqueous medium containing a dispersion stabilizer. Furthermore, 10% by mass hydrochloric acid was added to the aqueous medium to adjust the pH to 5.0 to obtain aqueous medium 1.

(Hydrolysis process of organosilicon compound for surface layer)
60.0 parts of ion-exchanged water was weighed into a reaction vessel equipped with a stirrer and a thermometer, and the pH was adjusted to 3.0 using 10% by mass hydrochloric acid. This was heated with stirring to bring the temperature to 70°C. Thereafter, 40.0 parts of methyltriethoxysilane, which is an organosilicon compound for the surface layer, was added, and the mixture was stirred for more than 2 hours to perform hydrolysis. The end point of the hydrolysis was visually confirmed when the oil and water did not separate and became a single layer, and was cooled to obtain a hydrolyzed solution of the organosilicon compound for the surface layer.

(Preparation process of polymerizable monomer composition)
・Styrene: 60.0 parts ・C. I. Pigment Blue 15:3: 6.5 parts The above materials were put into an attritor (manufactured by Mitsui Miike Kakoki Co., Ltd.), and further dispersed using zirconia particles with a diameter of 1.7 mm at 220 rpm for 5.0 hours to form a pigment. A dispersion was prepared. The following materials were added to the pigment dispersion.
・Styrene: 20.0 parts ・n-butyl acrylate: 20.0 parts ・Crosslinking agent (divinylbenzene): 0.3 parts ・Saturated polyester resin: 5.0 parts (propylene oxide modified bisphenol A (2 mole adduct) and terephthalic acid (molar ratio 10:12), glass transition temperature Tg = 68°C, weight average molecular weight Mw = 10000, molecular weight distribution Mw / Mn = 5.12)
- Fischer-Tropsch wax (melting point 78°C): 7.0 parts This was kept warm at 65°C, and T. K. Using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), the mixture was uniformly dissolved and dispersed at 500 rpm to prepare a polymerizable monomer composition.

(granulation process)
The temperature of the aqueous medium 1 was set at 70°C. K. While maintaining the rotational speed of the homomixer at 12,000 rpm, the polymerizable monomer composition was charged into aqueous medium 1, and 9.0 parts of t-butyl peroxypivalate as a polymerization initiator was added. The mixture was granulated for 10 minutes using the stirring device while maintaining the speed at 12,000 rpm.

(Polymerization process)
After the granulation process, the stirrer was replaced with a propeller stirring blade, and while stirring at 150 rpm, polymerization was carried out by maintaining the temperature at 70 °C for 5.0 hours, and the polymerization reaction was carried out by increasing the temperature to 85 °C and heating for 2.0 hours. and obtained core particles. When the temperature of the slurry was cooled to 55° C. and the pH was measured, the pH was 5.0. While stirring was continued at 55° C., 20.0 parts of a hydrolyzed solution of an organosilicon compound for surface layer was added to start forming a surface layer of toner particles. After holding the slurry as it was for 30 minutes, the slurry was adjusted to pH=9.0 to complete condensation using an aqueous sodium hydroxide solution, and was held for an additional 300 minutes to form a surface layer.

(Washing, drying process)
After the polymerization process is completed, the toner particle slurry is cooled, hydrochloric acid is added to the toner particle slurry to adjust the pH to 1.5 or less, and the mixture is stirred for 1 hour and separated into solid and liquid using a pressure filter to form a toner cake. I got it. This was reslurried with ion-exchanged water to form a dispersion liquid again, and then solid-liquid separation was performed using the aforementioned filter. After repeating the reslurry and solid-liquid separation until the electrical conductivity of the filtrate became 5.0 μS/cm or less, solid-liquid separation was finally performed to obtain a toner cake.

The obtained toner cake was dried using a flash jet dryer (manufactured by Seishin Enterprises), and fine and coarse powder was cut using a multi-division classifier utilizing the Coanda effect to obtain toner particles 1. The drying conditions were a blowing temperature of 90.degree. C., a dryer outlet temperature of 40.degree. C., and a supply rate of the toner cake so that the outlet temperature did not deviate from 40.degree. C. in accordance with the moisture content of the toner cake.

In this example, the obtained toner particles 1 were used as toner a without being externally added. Further, toners b to d were prepared by changing the conditions when adding the hydrolyzate (in the polymerization step) and the holding time after addition as shown in Table 1. Note that the pH of the slurry was adjusted using hydrochloric acid and an aqueous sodium hydroxide solution.

Toner e was not subjected to (hydrolysis step of organosilicon compound for surface layer). Instead, 15 parts of methyltriethoxysilane, an organosilicon compound for the surface layer, was added as a monomer (in the step of preparing a polymerizable monomer composition). (Polymerization step) After cooling to 70° C. and measuring pH, no hydrolyzate was added. While stirring at 70° C., the slurry was adjusted to pH 9.0 using an aqueous sodium hydroxide solution to complete condensation and held for an additional 300 minutes to form a surface layer. Other than that, a toner was produced in the same manner as toner a.

In this example, toners a to e were used without any external additives, but external additives may also be used.

The particle size, Martens hardness, and adhesion rate were measured by the method described in the detailed description. Table 2 below shows the Martens hardness and fixation rate of toners a to e.

<Experiment content 1>
In the configuration of this example, the following experiment was conducted.

A plurality of developing blades 21 having different radii of curvature R [mm] were manufactured (Table 3). In addition, the radius of curvature R [mm] and height H [mm] (see Fig. 4) of the outer curved surface (2102A) of the bent portion (2102) and the ten-point average roughness Rz were measured using a shape measuring microscope (manufactured by KEYENCE). VK-X200).

FIG. 6(a) is a diagram showing measurement angles when measuring the bent portion (2102) of blade b with a shape measuring microscope (VK-X200 manufactured by KEYENCE). The bent portion (2102) of the developing blade 21 was measured from an angle of 45 degrees.

FIG. 6(b) shows the radius of curvature R [mm] (Rb ) is a diagram showing the detection results.

The radius of curvature R [mm], height H [mm], and ten-point average roughness Rz of the outer peripheral curved surface of the bent portion of the developing blade 21 shown in Table 3 were all measured at the observation angle shown in FIG. 6. Ta.

As shown in Table 3, it can be seen that the smaller the radius of curvature R [mm] (Rb) of the outer peripheral side curved surface (2102A) of the bent portion 2102, the more Rz increases. In other words, the smaller the radius of curvature R [mm] is, the higher the convex portion is, and the easier it is for toner to stay in the convex portion, so that the toner is more likely to be fused to the convex portion.

Using toners a to e shown in Table 2 and blades a to d shown in Table 3, "development streaks" and "dropping" were evaluated.

The evaluation conditions were to leave the recording material overnight at room temperature and humidity (25°C/50%), and then to fully acclimatize it to the environment. The above evaluation was performed after intermittent testing (durability test). In this example, a horizontal line with an image coverage rate of 5% was used as the experimental image.

The evaluation method will be described in detail below.

<Evaluation of development streaks>
Print out a halftone image (toner coverage: 0.2 mg/cm ² ) on LETTER size XEROX Vitality paper (manufactured by XEROX, 75 g/m ² ), and mark development streaks A, B, and C as shown below. Ranked. It was also confirmed that the A and B ranks had no effect on image quality. in particular,
A: No vertical streaks in the paper ejection direction were observed on the developing roller or on the image.
B: There were slight thin stripes in the circumferential direction on both ends of the developing roller, and slight vertical stripes in the paper ejection direction on the image, but they were not significant enough to affect the image quality. .
C: A plurality of streaks were observed on the developing roller and on the image, which affected the image quality.

<Evaluation of drop-off>
After completing the durability test, the image forming apparatus was disassembled, and the presence or absence of toner "drop-off" (peeling condition) was investigated, and evaluation was made as pass "○" and fail "x".

The phenomenon of toner "dropping" in this evaluation refers to a state in which toner is not held on the developing roller downstream of the toner regulating part of the developing roller and falls under the gravity of the developing roller. be. If image formation is continued in a state where toner "drop-off" occurs, it is likely to lead to contamination within the image forming body or to the recording paper, which may cause a decrease in image quality.

<Experiment results 1>
Table 4 below shows the evaluation results of "development streaks" and "bottle drop" of this example.

In the configuration of this embodiment, a bending blade can be used by using a toner having a Martens hardness of 200 MPa or more and 1100 MPa or less when measured under a maximum load of 2.0×10 ⁻⁴ N. That is, even when a bent blade is used, since the toner has high hardness, the toner will not be fused to the blade even if the toner is repeatedly rubbed on the convex portion of the bent portion of the blade.

In addition, by using a developing blade in which the radius of curvature R [mm] of the contact portion between the developing blade and the developing roller is R≦0.3, peak pressure can be ensured, toner can be regulated, and droplets can be suppressed. Ta. Note that in the case of R<0.08, the radius of curvature of the bent portion of the developing blade is too small, making it difficult to manufacture because it tends to break during processing.

As can be understood from Table 4, when toners a to c are used and blades a to c are used, "peak pressure" to the developing roller is secured while suppressing "development streaks" caused by toner fusion. This made it possible to suppress "bottle dropping".

In addition, when Toner d was used, the Martens hardness was too hard at 1200 Mpa, so the surface of the developing blade and developing roller was easily damaged, the toner layer on the developing roller was not formed properly, and "developing streaks" occurred. did.

On the other hand, in the case of using toner e, since the Martens hardness was 185 MPa and the toner was soft, the toner adhered to the convex portion of the bent portion of the blade, and fusion occurred due to repeated rubbing. In the areas where the toner was fused, a toner layer was not formed on the surface of the developing roller, so "development streaks" also occurred.

Furthermore, in the case of using the blade e, since the radius of curvature R is large, the area of the contact portion with the developing roller is expanded, and the pressure is dispersed, making it difficult to secure the peak pressure against the developing roller. Therefore, the toner on the developing roller could not be regulated, and droplets occurred.

Based on the results of the various experiments described above, and through intensive research by the inventors of the present invention, we have found that while ensuring the contact pressure (peak pressure) of the regulating member against the developer carrier, the melting of the developer to the regulating blade has been achieved. We have developed a configuration that can reduce wear and tear.

That is, using a toner whose Martens hardness is 200 MPa or more and 1100 MPa or less when measured under the condition of a maximum load of 2.0 × 10 ^-4 N, the radius of curvature R [mm] of the contact portion between the developing blade and the developing roller is ] is 0.08≦R≦0.3. According to such a configuration, it is possible to ensure the peak pressure to the developing roller, suppress droplets, and avoid toner fusion.

(others)
In the above-described embodiment, a predetermined radius of curvature can be formed at the abutting portion by a processing method called "bending" on the free end of the developing blade. Note that in order to form the abutting portion to have a predetermined radius of curvature, a processing method other than "bending" may be used.

For example, there is a "polishing" method in which the free end of the developing blade is polished little by little. Note that "bending" is advantageous and desirable in terms of manufacturing cost compared to "polishing".

The configuration of this embodiment can be summarized as follows.

That is, the developing device of this embodiment includes a developer carrier (17) that carries developer, a developer frame (18) that rotatably supports the developer carrier, and a regulating member (21). have The regulating member is attached to the developing frame, and regulates the thickness of the developer (40) carried on the developer carrier by coming into contact with the surface of the developer carrier. Further, the regulating member includes a curved surface portion (2102) having a ridgeline (2101) that can come into contact with the surface of the developer carrier.

When the Martens hardness under the conditions of the maximum load of toner contained in the developer is 2.0 × 10 ^-4 N is HM, the radius of curvature of the curved portion is Rb, and the radius of curvature of the surface of the developer carrier is Rd. , 200MPa≦HM≦1100MPa, and 0.08mm≦Rb≦0.3mm.

Furthermore, the process cartridge (7) of this embodiment can include a developing device (4) and an image carrier (1) that carries a developer image.

The image forming apparatus (100) of this embodiment also includes a developing device (4), an image carrier (1) that carries a developer image, and a transfer member that transfers the developer image from the image carrier to a recording material. (9).

Further, in this embodiment, the regulating member (21) can have a first portion (2103) and a second portion (2104). Specifically, when viewed from the direction of the rotation axis (1701) of the developer carrier, one end (2103A) of the first portion is fixed to the developer frame (18) and extends from the developer frame side to the developer carrier side. It extends in the first direction (D11). One end (2104A) of the second portion is connected to the other end (2103B) of the first portion, and extends in a second direction (D12) intersecting the first direction. The curved surface portion (2102) is preferably formed at a location where the first portion (2103) and the second portion (2104) are connected.

Furthermore, in this embodiment, the second portion may be formed by bending the other end of the first portion, and it is desirable that the curved portion (2102) be formed at the bending portion.

In addition, in this embodiment, when viewed from the rotational axis direction of the developer carrier, the first direction and The distance in the orthogonal direction can be taken as H. At this time, it is preferable that 0.15 mm≦H≦0.5 mm.

Further, in this embodiment, when viewed from the direction of the rotation axis of the developer carrier, and when the angle between the first direction (D11) and the second direction (D12) is θ, 80°≦θ≦130° It is preferable that

Further, in this example, when the ten-point average roughness of the curved surface portion of the regulating member is Rz, it is preferable that 0 μm≦Rz≦11 μm.

Further, in this embodiment, the developer carrier can include an elastic layer (1702) having elasticity on the surface. In addition, it is preferable that the MD-1 hardness of the elastic layer is 20° or more and 60° or less, and the center line average roughness Ra of the surface roughness of the elastic layer is 0.2 or more and 2 or less. .

Further, in this embodiment, it is preferable that the regulating member is made of a metal member.

Further, in this embodiment, the developer may be a non-magnetic one-component developer.

Furthermore, in this embodiment, the radius of curvature Rb of the curved surface portion and the radius of curvature Rd of the surface of the developer carrier are as follows:
It is preferable that Rd>Rb.

Also, in this example, the toner particles of the toner can have a surface layer containing an organosilicon polymer.

Furthermore, in this example, the organosilicon polymer can have a structure represented by R-SiO _3/2 (Formula (1)). Note that R represents a hydrocarbon group having 1 or more and 6 or less carbon atoms.

Further, in this embodiment, the developing device is removably attached to the main body of the image forming apparatus that forms images.

1 Photosensitive drum (image carrier)
4 Developing unit (developing device)
7 Process cartridge 17 Developing roller (developer carrier)
18 Developing frame body 21 Developing blade (regulating member)
2101 Edge line 2102 Curved surface portion Rb, Rd Radius of curvature HM Martens hardness 40 Toner (developer)
100 Image forming device

Claims (14)

a developer carrier that carries a developer;
a developing frame body rotatably supporting the developer carrier;
A developing device comprising: a regulating member attached to the developing frame and regulating the thickness of the developer carried on the developer carrier by coming into contact with the surface of the developer carrier,
The regulating member is
a curved surface portion having a ridge line that can come into contact with the surface of the developer carrier;
When the Martens hardness under the condition of a maximum load of 2.0×10 ⁻⁴ N of the toner contained in the developer is HM, and the radius of curvature of the curved surface portion is Rb,
200MPa≦HM≦1100MPa,
0.08mm≦Rb≦ 0.3mm ,
A developing device , wherein the toner particles of the toner have a surface layer containing an organosilicon polymer . The regulating member is
a first portion having one end fixed to the developing frame and extending in a first direction from the developing frame side toward the developer carrying body when viewed from the rotation axis direction of the developer carrying body; ,
a second portion having one end connected to the other end of the first portion and extending in a second direction intersecting the first direction;
2. The developing device according to claim 1, wherein the curved surface portion is formed at a location where the first portion and the second portion are connected. The second portion is formed by bending the other end of the first portion,
3. The developing device according to claim 2, wherein the curved surface portion is formed at the bending portion. When viewed from the rotational axis direction of the developer carrier, the distance from the bending start position of the first portion to the other end of the second portion in the direction orthogonal to the first direction is defined as H. When,
4. The developing device according to claim 3, wherein 0.15 mm≦H≦0.5 mm. When viewed from the rotational axis direction of the developer carrier, when the angle between the first direction and the second direction is θ,
5. The developing device according to claim 2, wherein 80°≦θ≦130°. When the ten-point average roughness of the curved surface portion of the regulating member is Rz,
6. The developing device according to claim 1, wherein 0 μm≦Rz≦11 μm. The developer carrier includes an elastic layer having elasticity on the surface,
The MD-1 hardness of the elastic layer is 20° or more and 60° or less, and
7. The developing device according to claim 6, wherein the center line average roughness Ra of the surface roughness of the elastic layer is 0.2 or more and 2 or less. 8. The developing device according to claim 1, wherein the regulating member is made of a metal member. 9. The developing device according to claim 1, wherein the developer is a non-magnetic one-component developer. When the radius of curvature of the surface of the developer carrier is Rd,
The radius of curvature Rb of the curved surface portion and the radius of curvature Rd of the surface of the developer carrier are:
10. The developing device according to claim 1, wherein Rd>Rb. 11. The developing device according to claim 1, wherein the organosilicon polymer has a structure represented by formula (1).
R-SiO _3/2 formula (1)
(R represents a hydrocarbon group having 1 to 6 carbon atoms.) The developing device according to any one of claims 1 to 11 , wherein the developing device is removably attachable to an apparatus main body of an image forming apparatus that forms an image. The developing device according to any one of claims 1 to 12 ,
an image carrier that carries a developer image;
A process cartridge comprising: The developing device according to any one of claims 1 to 12 ,
an image carrier that carries a developer image;
a transfer member that transfers the developer image from the image carrier to a recording material;
An image forming apparatus comprising:

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