Image forming apparatus and process cartridge

Abstract

To provide an image forming apparatus that achieves both prevention of wear of a surface of an electrophotographic photoreceptor and prevention of decoloration of an image formed on embossed paper.SOLUTION: An image forming apparatus comprises: an electrophotographic photoreceptor; electrifying means that electrifies a surface of the electrophotographic photoreceptor; electrostatic charge image forming means that forms an electrostatic charge image on the surface of the electrophotographic photoreceptor; developing means that develops the electrostatic charge image formed on the surface of the electrophotographic photoreceptor as a toner image; an intermediate transfer body; primary transfer means that primarily transfers the toner image formed on the surface of the electrophotographic photoreceptor to a surface of the intermediate transfer body; secondary transfer means that secondarily transfers the toner image transferred to the surface of the intermediate transfer body to a surface of a recording medium; cleaning means having a cleaning member that is in contact with the surface of the electrophotographic photoreceptor and cleans the surface of the electrophotographic photoreceptor; and lubricant supply means that stores a lubricant solid body containing lubricant having a polygonal stitching coupling structure in a content of 92 mass% or more and 100 mass% or less, and supplies the lubricant to the surface of the electrophotographic photoreceptor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to an image forming apparatus and a process cartridge. [Background technology]

[0002] Image formation by electrophotography is performed, for example, by charging the surface of an electrophotographic photoreceptor, which is an image holder, forming an electrostatic charge image on the surface of the electrophotographic photoreceptor according to the image information, then developing this electrostatic charge image with a developer containing toner to form a toner image, and finally transferring and fixing this toner image to the surface of a recording medium.

[0003] Herein, Patent Document 1 discloses an image forming apparatus using an image carrier in which a lubricant film is formed on the surface of a photosensitive layer that carries a latent image, wherein the lubricant film is composed of a mixture of a fatty acid metal salt and a lubricating powder material consisting of at least one lubricating substance selected from melamine cyanurate, polytetrafluoroethylene, molybdenum disulfide, and fatty acid amide. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2007-121908 [Overview of the project] [Problems that the invention aims to solve]

[0005] In an electrophotographic image forming apparatus that uses an electrophotographic photoreceptor (hereinafter also referred to as "photoreceptor") as an image holder, for example, after transferring a toner image formed on the surface of the photoreceptor to a recording medium, the surface of the photoreceptor is cleaned by a cleaning member that comes into contact with the surface of the photoreceptor. As a method to suppress wear of the photoreceptor surface by the cleaning member, for example, a lubricant supply means is installed that supplies a lubricant contained in a lubricant solid to the contact position between the cleaning member and the photoreceptor.

[0006] However, when the image forming apparatus provided with the lubricant supply means is an intermediate transfer type, although the wear on the surface of the photoreceptor is suppressed, the transferability of the toner image from the intermediate transfer body to the recording medium may decrease. When the transferability of the toner image decreases, particularly in an image formed on a recording medium having large surface irregularities such as embossed paper (hereinafter also referred to as "irregular paper"), color bleeding due to the decrease in transferability may occur. Therefore, it is required to achieve both suppression of wear on the surface of the photoreceptor and suppression of color bleeding due to the decrease in transferability.

[0007] The present invention provides an image forming apparatus including an electrophotographic photoreceptor, charging means, electrostatic charge image forming means, developing means, an intermediate transfer body, primary transfer means, secondary transfer means, and cleaning means having a cleaning member that contacts the surface of the electrophotographic photoreceptor. The object is to provide an image forming apparatus that achieves both suppression of wear on the surface of the electrophotographic photoreceptor and suppression of color bleeding in an image formed on irregular paper, as compared with a case where the lubricant supply means is not provided or a case where the lubricant supply means contains a lubricant solid containing zinc stearate at a content rate of 8% by mass or more.

Means for Solving the Problems

[0008] Specific means for solving the above problems include the following aspects.

[0009] <1> An electrophotographic photoreceptor having a photosensitive layer, Charging means for charging the surface of the electrophotographic photoreceptor, Electrostatic charge image forming means for forming an electrostatic charge image on the charged surface of the electrophotographic photoreceptor, Developing means for accommodating an electrostatic charge developer containing toner for developing an electrostatic charge image and developing the electrostatic charge image formed on the surface of the electrophotographic photoreceptor as a toner image with the electrostatic charge developer, An intermediate transfer body on which the toner image is transferred to the surface, Primary transfer means for primarily transferring the toner image formed on the surface of the electrophotographic photoreceptor to the surface of the intermediate transfer body, Secondary transfer means for secondarily transferring the toner image transferred onto the surface of the intermediate transfer body onto the surface of a recording medium; Cleaning means having a cleaning member that contacts the surface of the electrophotographic photoreceptor and cleans the surface of the electrophotographic photoreceptor; A lubricant solid containing a lubricant having a multi-faceted stitch bond structure at a content rate of 92 mass% or more and 100 mass% or less, and supplying the lubricant having the multi-faceted stitch bond structure to the contact position between the cleaning member and the electrophotographic photoreceptor Lubricant supply means; An image forming apparatus comprising: <2> The image forming apparatus according to <1>, wherein the cleaning member is a cleaning blade. <3> The image forming apparatus according to <1> or <2>, wherein the lubricant supply means has a lubricant supply member that contacts the surface of the electrophotographic photoreceptor and supplies the lubricant having the multi-faceted stitch bond structure to the contact position between the cleaning member and the electrophotographic photoreceptor. <4> The image forming apparatus according to <3>, wherein the lubricant supply member is a rotary brush. <5> The image forming apparatus according to <4>, wherein the rotary brush has brush fibers having a thickness of 0.5 denier or more and 30 denier or less.

[0010] <6> The image forming apparatus according to any one of <1> to <5>, wherein the lubricant having the multi-faceted stitch bond structure contains melamine cyanurate. <7> The image forming apparatus according to <6>, wherein the lubricant solid is a compression molded body of particles of melamine cyanurate having a number average primary particle diameter of 10 μm or less. <8> The Martens hardness of the lubricant solid at 23 ° C is 24 N / mm 2 or more and 80 N / mm 2 or less, and the image forming apparatus according to any one of <1> to <7>. <9> The Martens hardness of the lubricant solid at 23 ° C is 30 N / mm 2More than 60N / mm 2 The following is: <8> The image forming apparatus described above.

[0011] <10> An electrophotographic photoreceptor having a photosensitive layer, A charging means for charging the surface of the electrophotographic photoreceptor, A cleaning means having a cleaning member that contacts the surface of the electrophotographic photoreceptor and cleans the surface of the electrophotographic photoreceptor, A lubricant supply means containing a lubricant solid containing a lubricant having a polygonal mesh bonding structure at a content of 92% to 100% by mass, and supplying the lubricant having the polygonal mesh bonding structure to the contact position between the cleaning member and the electrophotographic photoreceptor, Equipped with, A process cartridge that is attached to and detached from an image forming apparatus using an intermediate transfer method. [Effects of the Invention]

[0012] <1> , <3> , or <6> According to the present invention, an image forming apparatus is provided that includes an electrophotographic photoreceptor, a charging means, an electrostatic image forming means, a developing means, an intermediate transfer body, a primary transfer means, a secondary transfer means, and a cleaning means having a cleaning member that contacts the surface of the electrophotographic photoreceptor. Compared to an apparatus that does not include a lubricant supply means or an apparatus that includes a lubricant supply means containing a lubricant solid containing zinc stearate at a content of 8% by mass or more, the present invention provides an image forming apparatus that achieves both suppression of wear on the surface of the electrophotographic photoreceptor and suppression of color fading in the image formed on the textured paper. <2> According to the invention, even if the cleaning member is a cleaning blade, wear on the surface of the electrophotographic photoreceptor is suppressed compared to cases where a lubricant supply means is not provided. <4> According to the invention, an image forming apparatus is provided in which wear of the electrophotographic photoreceptor surface is suppressed compared to when the lubricant supply member is a rubber roll. <5> According to the invention, an image forming apparatus is provided in which wear on the surface of the electrophotographic photoreceptor is suppressed compared to cases where the thickness of the brush fibers of the rotating brush is less than 0.5 denier or more than 30 denier.

[0013] <7> According to the invention, an image forming apparatus is provided that suppresses color fading in images formed on textured paper compared to the case in which a lubricant solid is used, which is a compressed molded body of lubricant particles with a number average primary particle size of 10 μm or more. <8> According to the invention, the Martens hardness at 23°C is 24 N / mm². 2 Less than 80 N / mm 2 Compared to the case where a lubricant solid is used, an image forming apparatus is provided in which wear on the surface of the electrophotographic photoreceptor is suppressed. <9> According to the invention, the Martens hardness at 23°C is 30 N / mm². 2 Less than 60 N / mm 2 Compared to the case where a lubricant solid is used, an image forming apparatus is provided in which wear on the surface of the electrophotographic photoreceptor is suppressed.

[0014] <10> According to the present invention, a process cartridge for an intermediate transfer type image forming apparatus is provided, which includes an electrophotographic photoreceptor, a charging means, and a cleaning means having a cleaning member that contacts the surface of the electrophotographic photoreceptor, and which can be attached to and detached from the image forming apparatus, and which does not include a lubricant supply means or which includes a lubricant supply means containing a lubricant solid containing zinc stearate at a content of 8% by mass or more, and which achieves both suppression of wear on the surface of the electrophotographic photoreceptor and suppression of color fading in the image formed on the textured paper. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram showing an example of an image forming apparatus according to this embodiment. [Figure 2] This is a schematic diagram showing an example of a process cartridge according to this embodiment. [Modes for carrying out the invention]

[0016] The embodiments of this disclosure are described below. These descriptions and embodiments are illustrative and do not limit the scope of the embodiments.

[0017] In numerical ranges described in stages within this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in numerical ranges described within this disclosure, the upper or lower limit of that range may be replaced with the values ​​shown in the examples.

[0018] In this disclosure, each component may contain multiple types of the corresponding substance. When referring to the amount of each component in a composition in this disclosure, if there are multiple types of the substance corresponding to each component in the composition, it means the total amount of those multiple types of substances present in the composition unless otherwise specified.

[0019] [Image forming apparatus] The image forming apparatus according to this embodiment includes an electrophotographic photoreceptor having a photosensitive layer, a charging means for charging the surface of the electrophotographic photoreceptor, an electrostatic image forming means for forming an electrostatic image on the charged surface of the electrophotographic photoreceptor, a developing means containing an electrostatic image developer including an electrostatic image developing toner, and developing the electrostatic image formed on the surface of the electrophotographic photoreceptor as a toner image using the electrostatic image developer, an intermediate transfer body on which the toner image is transferred, and the toner image formed on the surface of the electrophotographic photoreceptor is transferred to the intermediate transfer The system comprises: a primary transfer means for primary transfer to the surface of a photograph; a secondary transfer means for secondary transfer of the toner image transferred to the surface of the intermediate transfer body to the surface of a recording medium; a cleaning means having a cleaning member that contacts the surface of the electrophotographic photoreceptor and cleans the surface of the electrophotographic photoreceptor; and a lubricant supply means containing a lubricant solid containing a lubricant having a polygonal mesh bonding structure at a content of 92% to 100% by mass, and supplying the lubricant having a polygonal mesh bonding structure to the contact position between the cleaning member and the electrophotographic photoreceptor.

[0020] Here, "polygonal mesh bond structure" refers to a bond structure in which a polygonal mesh structure is formed by the bonding of the constituent atoms. Hereinafter, lubricants having a polygonal mesh bonding structure will also be referred to as "specific lubricants."

[0021] In an image forming apparatus that transfers a toner image formed on the surface of a photoreceptor to a recording medium, and then cleans the surface of the photoreceptor with a cleaning member that contacts the surface of the photoreceptor, the photoreceptor rotates while the cleaning member is in contact with the surface of the photoreceptor. As a result, the surface of the photoreceptor may become prone to wear due to friction from the cleaning member. As described above, one method for suppressing wear on the photoreceptor surface by the cleaning member is to install a lubricant supply means that supplies lubricant contained in a lubricant solid to the contact position between the cleaning member and the photoreceptor. In an image forming apparatus equipped with the above lubricant supply means, for example, by supplying lubricant contained in a lubricant solid to the surface of the photoreceptor and forming a lubricant coating film, the frictional force of the cleaning member in contact with the surface of the photoreceptor is reduced, and wear on the photoreceptor is suppressed.

[0022] On the other hand, when lubricant contained in a lubricant solid is supplied to the surface of the photoreceptor, the transferability of the toner image from the intermediate transfer medium to the recording medium may decrease if the image forming apparatus uses an intermediate transfer method. In this case, color loss may occur in images formed on recording media with large surface irregularities, such as embossed paper (hereinafter also referred to as "textured paper"), due to the decrease in transferability. The reason why color loss occurs due to the decrease in transferability when lubricant is supplied to the surface of the photoreceptor is not clear, but it is speculated to be as follows. Lubricants supplied to the surface of a photoreceptor can deteriorate due to electrical loads, such as discharges from charging means that charge the surface of the photoreceptor. In particular, zinc stearate, which is commonly used as a lubricant, is thought to deteriorate when subjected to electrical loads, causing the carbon-carbon bonds in the carbon chain to break and the lamellar structure to collapse. When the deteriorated lubricant migrates to the surface of the intermediate transfer medium, it is presumed that the deteriorated lubricant increases the adhesion between the surface of the intermediate transfer medium and the toner image, making it more difficult for the toner image to be transferred to the recording medium, resulting in color loss due to decreased transferability.

[0023] In contrast, this embodiment includes a lubricant supply means containing a lubricant solid containing a specific lubricant at a concentration of 92% by mass or more and 100% by mass or less. In other words, 92% by mass or more of the lubricant supplied to the surface of the photoreceptor is the specific lubricant. Therefore, both suppression of wear on the surface of the photoreceptor and suppression of color fading in the image formed on the textured paper are achieved. Specifically, wear on the surface of the photoreceptor is suppressed compared to when there is no lubricant supply means, and color fading in the image formed on the textured paper is suppressed compared to when there is a lubricant supply means containing a lubricant solid containing zinc stearate at a concentration of 8% by mass or more. The reason why the image forming apparatus of this embodiment suppresses color fading in the image formed on the textured paper compared to when there is a lubricant supply means containing a lubricant solid containing zinc stearate at a concentration of 8% by mass or more is not clear, but it is presumed to be as follows.

[0024] Because the specific lubricant has a polygonal mesh bonding structure, the bonds are less likely to break even when subjected to electrical loads from discharge. Even if the bonds are partially broken, the mesh structure makes it difficult to decompose, and it is believed that interlayer sliding is maintained. Furthermore, because the lubricant solid contains 92% or more by mass of the specific lubricant and 8% or less by mass of components other than the specific lubricant, even if components other than the specific lubricant are affected by electrical loads, the lubricity of the lubricant as a whole contained in the lubricant solid is maintained and deterioration is suppressed. Therefore, even if the lubricant migrates to the surface of the intermediate transfer medium, the degradation of the migrated lubricant is suppressed. As a result, an increase in adhesion between the surface of the intermediate transfer medium and the toner image is unlikely, and it is presumed that color fading due to a decrease in transferability is suppressed even when forming an image on textured paper.

[0025] For the reasons stated above, it is presumed that by providing a lubricant supply means containing a lubricant solid containing a specific lubricant at a concentration of 92% to 100% by mass, it will be possible to achieve both the suppression of wear on the photoreceptor surface and the suppression of color fading in images formed on textured paper. The configuration of the image forming apparatus according to this embodiment will be described in detail below.

[0026] As described above, the image forming apparatus according to this embodiment comprises a photoreceptor, a charging means, an electrostatic image forming means, a developing means, an intermediate transfer body, a primary transfer means, a secondary transfer means, a cleaning means having a cleaning member that contacts the surface of the photoreceptor and cleans the surface of the photoreceptor, and a lubricant supply means that contains a lubricant solid containing a lubricant having a polygonal mesh bonding structure at a content of 92% to 100% by mass, and supplies the lubricant having a polygonal mesh bonding structure to the contact position between the cleaning member and the photoreceptor.

[0027] The image forming apparatus according to this embodiment may further include, for example, a means for removing static electricity by irradiating the surface of the photoreceptor with static electricity removal light after transferring the electrostatic image developing toner image and before charging.

[0028] The image forming apparatus according to this embodiment may be a cartridge structure (i.e., a process cartridge) in which at least a portion including a photoreceptor, a charging means, a cleaning means, and a lubricant supply means is attached to and detached from the image forming apparatus.

[0029] The following is an example of an image forming apparatus according to this embodiment, but is not limited to this example.

[0030] Figure 1 is a schematic diagram showing an example of an image forming apparatus according to this embodiment. As shown in Figure 1, the image forming apparatus 10 according to this embodiment is provided with, for example, a photoreceptor 12. The photoreceptor 12 is, for example, cylindrical in shape and is connected to a drive unit 27 such as a motor via a drive force transmission member (not shown) such as a gear, and is rotationally driven by the drive unit 27 around a rotation axis indicated by a black dot. In the example shown in Figure 1, it is rotationally driven in the direction of arrow A.

[0031] Around the photoreceptor 12, for example, a charging device 15 (an example of a charging means), an electrostatic image forming device 16 (an example of an electrostatic image forming means), a developing device 18 (an example of a developing means), a primary transfer device 31 (an example of a primary transfer means), a lubricant supply device 64 (an example of a lubricant supply means), a cleaning device 22 (an example of a cleaning means), and a static elimination device 24 are arranged in order along the rotational direction of the photoreceptor 12.

[0032] The primary transfer device 31 is positioned inside the intermediate transfer belt 50 (an example of an intermediate transfer body) and opposite the photoreceptor 12. The intermediate transfer belt 50 is wound around a drive roll 42, a support roll 44, and an opposing roll 46 that are in contact with the inner surface of the intermediate transfer belt 50, and travels in the direction of arrow B. On the image holding surface side of the intermediate transfer belt 50, a secondary transfer device 48 (an example of a secondary transfer means) is provided at a position opposite the opposing roll 46.

[0033] Furthermore, the image forming apparatus 10 is also equipped with a fixing device 26 having a fixing member 26A and a pressurizing member 26B positioned in contact with the fixing member 26A. The image forming apparatus 10 also has a control device 36 that controls the operation of each device (each part). The unit including the photoreceptor 12, charging device 15, electrostatic image forming device 16, developing device 18, primary transfer device 31, cleaning device 22, and lubricant supply device 64 corresponds to the image forming unit.

[0034] In the image forming apparatus 10, the photoreceptor 12, the charging device 15, the cleaning device 22, and the lubricant supply device 64 may be provided as an integrated process cartridge.

[0035] The details of each device (part) of the image forming apparatus 10 are described below. Note that reference numerals may be omitted.

[0036] <Photoconductor> The photoreceptor 12 has a photosensitive layer. The photosensitive layer may be a single-layer photosensitive layer that integrates the functions of a charge generating material and a charge transport material by containing them in the same photosensitive layer, or it may be a multilayer photosensitive layer with separate functions having a charge generating layer and a charge transport layer. When the photosensitive layer is a multilayer photosensitive layer, the order of the charge generating layer and the charge transport layer is not particularly limited, but it is preferable that the photoreceptor has a configuration in which the charge generating layer, the charge transport layer and the surface protective layer are arranged in this order on a conductive substrate. The photoreceptor 12 may also contain layers other than these layers. The photosensitive layer may be an organic photosensitive layer or an inorganic photosensitive layer.

[0037] <Charging device> The charging device 15 charges the surface of the photoreceptor 12. The charging device 15 includes, for example, a charging member 14 that is provided in contact with or without contact with the surface of the photoreceptor 12 to charge the surface of the photoreceptor 12, and a power supply 28 (an example of a voltage application unit for the charging member) that applies a charging voltage to the charging member 14. The power supply 28 is electrically connected to the charging member 14.

[0038] Examples of charging components 14 in the charging device 15 include contact-type chargers using conductive charging rollers, charging brushes, charging films, charging rubber blades, charging tubes, etc. Other examples of charging components 14 include non-contact type roller chargers, scorotron chargers or corotron chargers utilizing corona discharge, and other known chargers.

[0039] <Electrostatic image forming device> The electrostatic image forming apparatus 16 forms an electrostatic image on the surface of a charged photoreceptor 12. Specifically, for example, the electrostatic image forming apparatus 16 irradiates the surface of the photoreceptor 12, which has been charged by a charging member 14, with light L modulated based on the image information of the image to be formed, thereby forming an electrostatic image on the photoreceptor 12 that corresponds to the image information.

[0040] Examples of electrostatic image forming apparatus 16 include optical equipment having a light source that exposes an image-like object with light such as semiconductor laser light, LED light, or liquid crystal shutter light.

[0041] <Developing equipment> The developing device 18 is provided, for example, downstream of the photoreceptor 12 in the rotational direction from the irradiation position of light L by the electrostatic image forming device 16. The developing device 18 is provided with a housing for housing the electrostatic image developer. This housing contains the electrostatic image developer having an electrostatic image developing toner. The electrostatic image developing toner preferably includes, for example, toner particles containing a binder resin and an external additive added to the toner particles. The electrostatic image developer may be a one-component developer consisting of only the electrostatic image developing toner, or a two-component developer containing the electrostatic image developing toner and a carrier. The electrostatic image developer may be magnetic or non-magnetic. The electrostatic image developing toner is stored in a charged state within the developing device 18, for example.

[0042] The developing apparatus 18 includes, for example, a developing member 18A that develops the electrostatic image formed on the surface of the photoreceptor 12 using a developer containing an electrostatic image developing toner, and a power supply 32 that applies a developing voltage to the developing member 18A. The developing member 18A is electrically connected to, for example, the power supply 32.

[0043] The developing element 18A of the developing device 18 is selected according to the type of developer, but an example is a developing roll having a developing sleeve with a magnet built in.

[0044] The developing device 18 (including the power supply 32) is electrically connected to, for example, a control device 36 provided in the image forming apparatus 10, and is driven and controlled by the control device 36 to apply a developing voltage to the developing member 18A. The developing member 18A to which the developing voltage is applied has a developing potential corresponding to the developing voltage. The developing member 18A having a developing potential holds, for example, the developer contained in the developing device 18 on its surface and supplies the electrostatic image developing toner contained in the developer from inside the developing device 18 to the surface of the photoreceptor 12. On the surface of the photoreceptor 12 to which the electrostatic image developing toner has been supplied, the formed electrostatic image is developed as an electrostatic image developing toner image.

[0045] <Intermediate Transfer Belt> The intermediate transfer belt 50 is supported by a drive roll 42, a support roll 44, and an opposing roll 46, and rotates in the direction of arrow B. The electrostatic image developing toner image formed on the surface of the photoreceptor 12 by the primary transfer device 31 is transferred to the surface of the intermediate transfer belt 50. When the electrostatic image developing toner image transferred to the surface of the intermediate transfer belt 50 reaches between the secondary transfer device 48 and the opposing roll 46, it is transferred from the surface of the intermediate transfer belt 50 to the surface of the recording medium P. The intermediate transfer belt 50 is a belt-shaped material containing semiconducting polyimide, polyamide-imide, polycarbonate, polyarylate, polyester, rubber, etc. Alternatively, a drum-shaped intermediate transfer body may be used instead of the intermediate transfer belt 50.

[0046] <Transfer device> The primary transfer device 31 is provided, for example, downstream of the developing member 18A in the rotational direction of the photoreceptor 12. The primary transfer device 31 includes, for example, a primary transfer member 20 that transfers the electrostatic image developing toner image formed on the surface of the photoreceptor 12 to the intermediate transfer belt 50, and a power supply 30 that applies a primary transfer voltage to the primary transfer member 20. The primary transfer member 20 is, for example, cylindrical and transports the photoreceptor 12 with the intermediate transfer belt 50 sandwiched between it. The primary transfer member 20 is electrically connected to, for example, the power supply 30.

[0047] The secondary transfer apparatus 48 includes, for example, a secondary transfer member 52 that transfers an electrostatic image developing toner image transferred to the surface of the intermediate transfer belt 50 to a recording medium P, and a power supply 34 that applies a secondary transfer voltage to the secondary transfer member 52. The secondary transfer member 52 is, for example, cylindrical in shape and transports the recording medium P between itself and the opposing roll 46. The secondary transfer member 52 is electrically connected to, for example, the power supply 34.

[0048] Examples of primary transfer members 20 and secondary transfer members 52 include contact-type transfer chargers using belts, rollers, films, rubber cleaning blades, etc., scorotron transfer chargers utilizing corona discharge, and non-contact type transfer chargers that are known themselves, such as corotron transfer chargers.

[0049] The primary transfer device 31 (including the power supply 30) is electrically connected to, for example, a control device 36 provided in the image forming apparatus 10, and is driven and controlled by the control device 36 to apply a primary transfer voltage to the primary transfer member 20. The primary transfer member 20 to which the primary transfer voltage is applied has a transfer potential corresponding to the primary transfer voltage.

[0050] When a transfer voltage opposite in polarity to the electrostatic image developing toner that constitutes the electrostatic image developing toner image formed on the photoreceptor 12 is applied to the primary transfer member 20 from the power supply 30 of the primary transfer member 20, for example, a transfer electric field of electric field strength is formed in the region where the photoreceptor 12 and the primary transfer member 20 face each other (see transfer region 32A in Figure 1), causing each electrostatic image developing toner constituting the electrostatic image developing toner image on the photoreceptor 12 to move from the photoreceptor 12 to the primary transfer member 20 side by electrostatic force.

[0051] Similarly, the secondary transfer device 48 is electrically connected to, for example, the control device 36, and is driven and controlled by the control device 36 to apply a secondary transfer voltage to the secondary transfer member 52. When a transfer voltage with the opposite polarity to the electrostatic image developing toner that constitutes the electrostatic image developing toner image transferred on the intermediate transfer belt 50 is applied to the secondary transfer member 52 from the power supply 34 of the secondary transfer member 52, a transfer electric field of electric field strength is formed that moves each electrostatic image developing toner constituting the electrostatic image developing toner image on the intermediate transfer belt 50 from the intermediate transfer belt 50 to the secondary transfer member 52 side by electrostatic force.

[0052] The recording medium P is housed in a housing (not shown), for example, and is transported from this housing along a transport path 54 by a plurality of transport members (not shown), until it reaches the region where the opposing roll 46 and the secondary transfer member 52 face each other. In the example shown in Figure 1, it is transported in the direction of arrow C. Once the recording medium P reaches the transfer region, the electrostatic image developing toner image on the intermediate transfer belt 50 is transferred to it by the transfer electric field formed in that region, for example, when a secondary transfer voltage is applied to the secondary transfer member 52. That is, for example, the electrostatic image developing toner image is transferred onto the recording medium P by the movement of the electrostatic image developing toner from the surface of the intermediate transfer belt 50 to the recording medium P. Suitable recording media P include, for example, plain paper used in electrophotographic photocopiers and printers, OHP sheets, coated paper with the surface of plain paper coated with resin, art paper for printing, embossed paper, and other textured papers.

[0053] <Cleaning device> The cleaning device 22 is located downstream of the lubricant supply device 64 in the rotational direction of the photoreceptor 12. The cleaning device 22 transfers the electrostatic image developing toner image to the intermediate transfer belt 50, and after the lubricant is supplied from the lubricant supply device 64 to the surface of the photoreceptor 12, it cleans any residual toner and other substances adhering to the photoreceptor 12. Specifically, the cleaning device 22 cleans not only residual toner but also discharge products generated by the charging means, paper dust, and other adhering substances.

[0054] The cleaning device 22, for example, has a cleaning blade 220, and removes deposits from the surface of the photoreceptor 12 by bringing the tip of the cleaning blade 220 into contact with the photoreceptor 12 in a direction opposite to the rotation direction of the photoreceptor 12. The tip of the cleaning blade 220 is facing in a direction opposite to the rotation direction of the photoreceptor 12 (direction of arrow A), and in this state it is in contact with the surface of the photoreceptor 12.

[0055] The cleaning blade 220 is an elastic plate-like object. The materials used to construct the cleaning blade 220 include, for example, elastic materials such as silicone rubber, fluororubber, ethylene-propylene-diene rubber, and polyurethane rubber. Among these, polyurethane rubber is preferred because it exhibits excellent mechanical properties such as abrasion resistance, chipping resistance, and creep resistance.

[0056] The cleaning blade 220 is supported by a support member attached to the side opposite to the side that contacts the photoreceptor 12. This support member presses the cleaning blade 220 against the photoreceptor 12 with the aforementioned pressure. Examples of support members include metal materials such as aluminum and stainless steel. A bonding layer, such as an adhesive, may be present between the support member and the cleaning blade 220 to bond them together. The cleaning device may include known components other than the cleaning blade 220 and the support member that supports it. Furthermore, the cleaning device may have other cleaning members, such as a cleaning brush, instead of the cleaning blade 220. In this embodiment, since the lubricant supply means is provided that contains a lubricant solid containing a specific lubricant at a concentration of 92% to 100% by mass, wear on the photoreceptor surface is suppressed even if the cleaning device has a cleaning blade as a cleaning member.

[0057] <Lubricant supply device> The lubricant supply device 64 is located downstream of the primary transfer device 31 in the rotational direction of the photoreceptor 12, and comprises a lubricant solid 66A, a lubricant supply member 66B, and a leveling member 77. The lubricant supply device 64 is positioned in contact with the surface of the photoreceptor 12. The leveling member 77 levels the lubricant supplied to the surface of the photoreceptor 12. A preferred embodiment of the leveling member is the one described above as an example of the cleaning blade 220. Although not shown in the figures, the lubricant supply device 64 may also include a plate-shaped member that mechanically knocks off the electrostatic image developing toner adhering to the rotating brush.

[0058] The lubricant supply member 66B is disposed in contact with, for example, the lubricant solid 66A and the photoreceptor 12. The lubricant supply member 66B supplies lubricant to the contact position with the photoreceptor 12. Examples of the lubricant supply member 66B include a rotary brush, a rubber roll, etc., and among these, a rotary brush is preferable. When the lubricant supply member 66B is a rotary brush, for example, the scraping property of the lubricant solid 66A is improved compared to the case where the lubricant supply member 66B is a rubber roll, and the lubricant is easily supplied to the surface of the photoreceptor, so that the wear suppression effect on the surface of the photoreceptor is easily obtained.

[0059] As the lubricant supply device 64, for example, by bringing the lubricant solid 66A into contact with the lubricant supply member 66B, the lubricant contained in the lubricant solid 66A is adhered, and the surface of the lubricant supply member 66B to which the lubricant is adhered is brought into contact with the surface of the photoreceptor 12, so that the adhered lubricant is supplied to the surface of the photoreceptor 12. This is preferable. For example, when the lubricant supply member 66B is a rotary brush, as shown in FIG. 1, the lubricant solid 66A and the rotary brush as the lubricant supply member 66B are in contact with each other, and the rotary brush and the photoreceptor 12 are in contact with each other, and the rotary brush is rotated. Thereby, the lubricant adheres to the rotary brush, and the adhered lubricant is supplied to the surface of the photoreceptor 12. The lubricant supplied to the surface of the photoreceptor 12 forms a lubricant film on the surface of the photoreceptor 12.

[0060] Examples of the brush fibers (hereinafter also referred to as "fibers") of the rotary brush include resin fibers such as nylon, acrylic, polypropylene, and polyester. As the fiber density of the rotary brush, for example, 15×10 3 tufts / inch 2 or more and 120×10 3 tufts / inch 2 or less (that is, 23.4 tufts / mm 2 or more and 186 tufts / mm 2 or less), and from the viewpoint of uniform coating property, 50×10 3Books / inch 2 The above 120 x 10 3 Books / inch 2 The following (i.e., 78 pieces / mm) 2 186 strands / mm 2 The following range is preferred. The fiber length of the rotating brush can range from 1.0 mm to 7.0 mm, for example, and from the viewpoint of contact stability, a range of 4.0 mm to 7.0 mm is preferred. From the viewpoint of improving the scraping performance of the lubricant, the thickness of the rotating brush fibers is preferably in the range of 0.5 denier to 30 denier, and more preferably in the range of 1 denier to 30 denier. When the thickness of the rotating brush fibers is within the above range, the scraping force is increased compared to when the fibers are thinner, thereby improving the scraping performance of the lubricant. Furthermore, when the thickness of the rotating brush fibers is within the above range, the lubricant can be scraped more stably compared to when the fibers are thicker (i.e., it is less likely that the solid lubricant will be chipped off due to the fibers being too thick), thus improving the scraping performance of the lubricant. As a result of the improved scraping performance of the lubricant, the lubricant is more easily supplied to the surface of the photoreceptor, and the wear suppression effect on the surface of the photoreceptor is more easily obtained. The amount of fiber penetration into the surface of the photoreceptor 12 in the rotating brush should be, for example, 0.3 mm to 1.5 mm.

[0061] The ratio Hm / Hf of the Martens hardness of the lubricant solid 66A at 23°C to the Martens hardness Hf of the fibers in the rotating brush is preferably 1 or less, and more preferably 0.8 or less. When the ratio Hm / Hf is within the above range, lubricant can be scraped off the lubricant solid more stably compared to when it is greater than the above range. In other words, if the lubricant solid is too hard compared to the fibers of the rotating brush, it becomes difficult to scrape off the lubricant. The Martens hardness Hf of the fibers in a rotating brush is measured as follows. Specifically, brush fibers cut to an appropriate length are placed on a Si wafer, and a compression test is performed using a Shimadzu DUH-211 ultramicro hardness tester.

[0062] The rotation speed of the rotating brush or rubber roll should be varied according to the peripheral speed of the photoreceptor 12, but for example, the relative speed ratio with respect to the photoreceptor 12 should be between 0.5 and 1.5. Also, the rotation direction of the rotating brush or rubber roll may be the same as or opposite to the rotation direction of the photoreceptor 12.

[0063] (Lubricant solids) The following describes the details of the lubricant solid 66A. Note that symbols may be omitted.

[0064] -Components contained in lubricant solids- The lubricant solid according to this embodiment contains a lubricant having a polygonal mesh bonding structure (i.e., a specific lubricant) in a content of 92% to 100% by mass. The specified lubricant is not particularly limited as long as it is a lubricant having a polygonal mesh bonding structure. However, the polygonal mesh bonding structure is preferably a planar polygonal mesh bonding structure. Examples of specific lubricants include layered compounds having a polygonal mesh bonding structure. Layered compounds are compounds with a layered structure where the interlayer distance is in the angstrom range, and are thought to exhibit lubrication due to cleavage and the sliding of layers against each other.

[0065] Specific examples of specific lubricants include melamine cyanurate, boron nitride, molybdenum disulfide, graphite fluoride, mica, graphite, talc, tungsten disulfide, cadmium iodide, phthalocyanine, and metallic phthalocyanine. Furthermore, the lubricant solid may contain only one type of specific lubricant, or it may contain two or more types. From the viewpoint of easily exhibiting its function as a lubricant and being resistant to degradation due to electrical discharge, among these, melamine cyanurate, boron nitride, and molybdenum disulfide are preferred, melamine cyanurate and boron nitride are more preferred, and melamine cyanurate is even more preferred.

[0066] The content of the specific lubricant is 92% by mass or more and 100% by mass or less of the total lubricant solids. From the viewpoint of supplying a lubricant that is less susceptible to deterioration due to discharge, it is preferably 95% by mass or more and 100% by mass or less, and more preferably 99% by mass or more and 100% by mass or less.

[0067] Lubricant solids may contain components other than specified lubricants, as long as their content is 8% by mass or less of the total lubricant solids. Other components besides the specified lubricant include, for example, lubricants other than the specified lubricant. Examples of lubricants other than the specified lubricant include fatty acid metal salts. The fatty acid in the fatty acid metal salt may be either a saturated fatty acid or an unsaturated fatty acid, and examples include fatty acids with 10 to 25 carbon atoms (preferably 12 to 22 carbon atoms). The carbon number of the fatty acid includes the carbon atoms of the carboxyl group. Examples of metals in the fatty acid metal salt include divalent metals, such as magnesium, calcium, aluminum, barium, and zinc. Specific examples of fatty acid metal salts include, for example, zinc stearate and zinc laurate. If the lubricant solid contains lubricants other than the specified lubricant, it may contain only one type of lubricant other than the specified lubricant, or it may contain two or more types. From the viewpoint of exhibiting lubricity, the total content of the specified lubricant and other lubricants is preferably 98% by mass or more, more preferably 99% by mass or more, and even more preferably 99.5% by mass or more, relative to the total lubricant solids.

[0068] -Form and properties of lubricant solids- The shape of the lubricant solid is not particularly limited and may be rectangular, cylindrical, cubic, or the like. The lubricant solid may have surface irregularities that conform to the surface shape of the contact surface with the lubricant solid on the lubricant supply member. For example, if the lubricant supply member is cylindrical and the cylindrical side surface contacts the lubricant solid, the lubricant solid may have a concave surface that conforms to the cylindrical side surface. Having surface irregularities that conform to the surface shape of the lubricant supply member improves the scraping ability of the lubricant solid.

[0069] The volume of a single lubricant solid is not particularly limited; for example, 0.01 cm³. 3 More than 100000cm 3 The following ranges are listed, including 0.1 cm. 3 More than 10000cm 3 The following range is also acceptable: 1 cm 3 More than 1600cm 3 The following range is also acceptable. For example, if the lubricant solid is in the shape of a rectangular prism, examples include a rectangular prism with a length of 10 cm to 400 cm, a width of 5 mm to 20 mm, and a thickness of 3 mm to 20 mm.

[0070] The Martens hardness of the lubricant solid at 23°C (hereinafter also simply referred to as "Martens hardness") is 24 N / mm². 2 More than 80N / mm 2 The following is preferable: 30 N / mm 2 More than 60N / mm 2 More preferably, the following: 35 N / mm 2 More than N / 45mm 2 The following is even more preferable: When the Martens hardness of the lubricant solid is within the above range, the strength of the lubricant solid is higher compared to when it is lower, and the collapse of the solid is suppressed when the lubricant is scraped off by the lubricant supply member. Also, when the Martens hardness of the lubricant solid is within the above range, the scraping performance of the lubricant by the lubricant supply member is improved compared to when it is higher than the above range. By achieving both strength and scraping performance of the lubricant solid, the lubricant is more easily supplied to the photoreceptor surface, and the wear suppression effect on the photoreceptor surface is more easily obtained.

[0071] The above Martens hardness is measured by the following method. Specifically, the lubricant solid to be measured is first placed in a Fischer Instruments measuring device (PICODENTOR HM500). Then, under conditions of 23°C, the load on the surface of the lubricant solid is continuously increased using a Vickers indenter. The Martens hardness value is obtained by dividing the maximum load (30 mN) by the surface area penetrated by the Vickers indenter. The above measurement is performed at three arbitrary locations on the surface of the lubricant solid, and the average of the obtained values ​​is taken as the Martens hardness of the lubricant solid.

[0072] Methods for controlling the Martens hardness of a lubricant solid to within the aforementioned range include, for example, when the lubricant solid is a compressed molded body of lubricant particles described later, controlling it by adjusting compression conditions such as pressure during compression molding, or controlling it by adjusting the number-average primary particle size of the lubricant particles used.

[0073] From the viewpoint of ease of controlling Martens hardness, the lubricant solid is preferably a compressed molded body of lubricant particles. Certain lubricants are generally distributed as lubricant particles. Furthermore, because certain lubricants are difficult to melt even when heated, it is difficult to heat, melt, and solidify the particles of these lubricants that are distributed. For this reason, it is preferable to apply a compression molding method as a method for producing lubricant solids containing 92% by mass or more of the specific lubricant.

[0074] A compression molded body of lubricant particles can be obtained, for example, by supplying lubricant particles to a mold and compressing them. The pressure used during compression molding is set at 30 kgf / cm², from the viewpoint of controlling the Martens hardness within the aforementioned range and achieving both strength and scrapability of the lubricant solids. 2 More than 110kgf / cm 2 Preferably, it is 38 kgf / cm². 2 More than 80kgf / cm 2It is more preferable that the following conditions are met: 45 kgf / cm² 2 More than 55kgf / cm 2 The following is even more preferable: By setting the pressure during compression molding within the above range, both the strength and scrapability of the lubricant solid can be achieved even if the lubricant solid does not contain a binder resin. In other words, the lubricant solid does not need to contain a binder resin. The loading time during compression molding can be, for example, in the range of 1 second to 60 seconds, preferably in the range of 2 seconds to 30 seconds, and more preferably in the range of 5 seconds to 15 seconds.

[0075] The compression molded body of lubricant particles is preferably a compression molded body of lubricant particles having a number-average primary particle size of 10 μm or less. When the number-average primary particle size of the lubricant particles is within the above range, the transferability of the toner image is improved when lubricant is supplied to the surface of the photoreceptor in an intermediate transfer type image forming apparatus, compared to when it is larger than the above range. The reason for this is not clear, but it is presumed to be as follows. In this embodiment, more than 92% by mass of the lubricant particles constituting the lubricant solid, which is a compressed molded body of lubricant particles, are particles of a specific lubricant. And, because the number-average primary particle size of the particles of the specific lubricant is small, the small-particle-sized particles of the specific lubricant migrate to the surface of the intermediate transfer body and exist between the surface of the intermediate transfer body and the toner image. As a result, the adhesion force of the toner image to the intermediate transfer body is weakened, the transferability is improved, and color fading of the image formed on uneven paper is suppressed. Furthermore, because the number-average primary particle size of the lubricant particles is within the above range, when lubricant is supplied to the surface of the photoreceptor in an image forming apparatus, wear of the photoreceptor is more suppressed compared to when it is larger than the above range. The reason for this is not entirely clear, but it is presumed that a smaller number-average primary particle size of the lubricant particles allows the lubricant particles to spread more evenly across the surface of the photoreceptor, thereby making it easier for the lubricant to function effectively.

[0076] From the above viewpoint, the number-average primary particle size of the lubricant particles is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 2 μm or less. When a lubricant solid contains multiple types of lubricant particles, the number-average primary particle size of the lubricant particles refers to the number-average value of the primary particle sizes of all multiple types of lubricant particles contained in the lubricant solid. The number-average primary particle size of lubricant particles constituting a lubricant solid, which is a compressed molded body of lubricant particles, is measured by observing the surface of the lubricant solid with a magnifying microscope. Specifically, the surface of the lubricant solid is observed at 150x magnification using a magnifying microscope (KEYENCE, product name: VK-9510), and the number-average particle size of the lubricant particles is determined by taking the number average of the equivalent circular diameters of 10 observed lubricant particles.

[0077] <Static eliminator> The static elimination device 24 is, for example, located downstream of the cleaning device 22 in the rotational direction of the photoreceptor 12. After the toner image has been transferred, the static elimination device 24 exposes the surface of the photoreceptor 12 to remove static electricity. Specifically, for example, the static elimination device 24 is electrically connected to a control device 36 provided in the image forming apparatus 10, and is driven and controlled by the control device 36 to expose the entire surface of the photoreceptor 12 (specifically, for example, the entire image forming area) to remove static electricity.

[0078] Examples of static elimination devices 24 include devices having a light source such as a tungsten lamp that emits white light or a light-emitting diode (LED) that emits red light.

[0079] <Fusing device> The fixing device 26 is, for example, located downstream of the secondary transfer device 48 in the transport direction of the transport path 54 of the recording medium P. The fixing device 26 has a fixing member 26A and a pressurizing member 26B positioned in contact with the fixing member 26A, and fixes the toner image transferred onto the recording medium P at the contact portion between the fixing member 26A and the pressurizing member 26B. Specifically, for example, the fixing device 26 is electrically connected to a control device 36 provided in the image forming apparatus 10, and is driven and controlled by the control device 36 to fix the toner image transferred onto the recording medium P to the recording medium P by heat and pressure.

[0080] Examples of the fixing device 26 include known fixing devices such as hot roller fixing devices and oven fixing devices. Specifically, for example, the fixing device 26 may be a well-known fixing device comprising a fixing roll or fixing belt as a fixing member 26A and a pressure roll or pressure belt as a pressure member 26B.

[0081] Here, the recording medium P, which has been transported along the transport path 54 and passed through the secondary transfer device 48 to which the toner image has been transferred, is further transported along the transport path 54 by a transport member (not shown) to the installation position of the fixing device 26, where the toner image on the recording medium P is fixed.

[0082] The recording medium P, on which the image has been formed by fixing the toner image, is discharged to the outside of the image forming apparatus 10 by a plurality of transport members (not shown in the figure). The photoreceptor 12 is then discharged by the static elimination device 24 and then recharged to a charging potential by the charging device 15.

[0083] <Operation of the image forming apparatus> An example of the operation of the image forming apparatus 10 according to this embodiment will be described. Note that various operations of the image forming apparatus 10 are performed by a control program executed in the control device 36.

[0084] The image forming operation of the image forming apparatus 10 will be described. First, the surface of the photoreceptor 12 is charged by the charging device 15. The electrostatic image forming device 16 exposes the charged surface of the photoreceptor 12 based on image information. This forms an electrostatic image on the photoreceptor 12 corresponding to the image information. In the developing device 18, the electrostatic image formed on the surface of the photoreceptor 12 is developed using a developer containing electrostatic image developing toner. This forms an electrostatic image developing toner image on the surface of the photoreceptor 12. In the primary transfer device 31, the electrostatic image developing toner image formed on the surface of the photoreceptor 12 is transferred to the intermediate transfer belt 50. The electrostatic image developing toner image transferred to the intermediate transfer belt 50 is transferred to the recording medium P by the secondary transfer device 48. The electrostatic image developing toner image transferred to the recording medium P is fixed by the fixing device 26. Meanwhile, the lubricant contained in the lubricant solid 66A is supplied to the surface of the photoreceptor 12 after the electrostatic image developing toner image has been transferred, by the lubricant supply device 64. The surface of the photoreceptor 12 to which the lubricant has been supplied is cleaned by the cleaning blade 220 of the cleaning device 22, and then static electricity is removed by the static elimination device 24.

[0085] [Processing cartridge] The process cartridge according to this embodiment comprises an electrophotographic photoreceptor having a photosensitive layer, a charging means for charging the surface of the electrophotographic photoreceptor, a cleaning means having a cleaning member that contacts the surface of the electrophotographic photoreceptor and cleans the surface of the electrophotographic photoreceptor, and a lubricant supply means that contains a lubricant solid containing a lubricant having a polygonal mesh bonding structure at a content of 92% to 100% by mass, and supplies the lubricant having a polygonal mesh bonding structure to the contact position between the cleaning member and the electrophotographic photoreceptor, and is attached to and detached from an intermediate transfer type image forming apparatus.

[0086] The process cartridge according to this embodiment is not limited to the above configuration, and may also include an electrophotographic photoreceptor, a charging means, a cleaning means, a lubricant supply means, and, as necessary, at least one selected from other means such as an electrostatic image forming means, a developing means, an intermediate transfer body, a primary transfer means, and a secondary transfer means.

[0087] The following shows an example of a process cartridge according to this embodiment, but it is not limited to this example. The main parts shown in the figure will be described, and other parts will not be explained.

[0088] Figure 2 is a schematic diagram showing the process cartridge according to this embodiment. The process cartridge 200 shown in Figure 2 is constructed by integrally combining and holding a photoreceptor 207, a charging roll 208 (an example of a charging means), a developing device 211 (an example of a developing means), a lubricant supply device 264 (an example of a lubricant supply means), and a photoreceptor cleaning device 213 (an example of a cleaning means) provided around the photoreceptor 207, within a housing 217 equipped with a mounting rail 216 and an opening 218 for exposure, and is thus formed into a cartridge.

[0089] In Figure 2, 209 is an exposure apparatus (an example of electrostatic image formation means), 212 is a primary transfer roll (an example of primary transfer means), 250 is an intermediate transfer belt (an example of an intermediate transfer body), 222 is a drive roll that also serves as an intermediate transfer belt static elimination means, 224 is a support roll, 226 is a secondary transfer roll (an example of secondary transfer means), 228 is a fixing apparatus (an example of fixing means), and 300 is recording paper (an example of a recording medium).

[0090] Note that the photoreceptor 207, charging roll 208, exposure device 209, developing device 211, intermediate transfer belt 250, primary transfer roll 212, secondary transfer roll 226, recording paper 300, photoreceptor cleaning device 213, lubricant supply device 264, and fixing device 228 shown in Figure 2 are the same as those used for the photoreceptor 12, charging device 15, electrostatic image forming device 16, developing device 18, intermediate transfer belt 50, primary transfer device 31, secondary transfer device 48, recording medium P, cleaning device 22, lubricant supply device 64, and fixing device 26 shown in Figure 1, respectively, and a detailed explanation is omitted. [Examples]

[0091] The following describes embodiments of this disclosure, but this disclosure is not limited to these embodiments. In the following description, unless otherwise specified, "parts" and "%" all refer to mass.

[0092] [Example 1] <Preparation of solid lubricant> One part by mass of melamine cyanurate particles (manufactured by Nissan Chemical Corporation, product name: MC-6000, number average primary particle size: <2 μm) was placed in a mold of a compression molding machine (manufactured by SHIMADZU, product name: manual hydraulic pump), and compression molding was performed under the conditions shown in Table 1, with a temperature of 23°C and a humidity of 55% RH, using the pressure and load time of 10 seconds, to obtain a compression molded body of lubricant solid. The resulting lubricant solid was cylindrical in shape and had a volume of 883 mm³. 3 (Radius 7.5 mm, Thickness 5 mm) Table 2 shows the results of measuring the Martens hardness of the obtained lubricant solid using the method described above. Table 2 also shows the results of measuring the number-average primary particle size of the lubricant particles contained in the obtained lubricant solid using the method described above (see "Primary Particle Size" in the table). A cylindrical lubricant solid with a radius of 7.5 mm and a thickness of 5 mm was cut off at the end with a knife to form a rectangular prism with a length of 10 mm, a width of 10 mm, and a thickness of 5 mm. 33 of these rectangular prisms were connected and arranged to form a structure measuring 330 mm in length, 10 mm in width, and 5 mm in thickness, which was used for the evaluation described below.

[0093] <Fabrication of an image forming apparatus> As the image forming apparatus, we prepared a modified version of the image forming apparatus "Product Name: Iridesse Production Press (manufactured by Fujifilm Business Innovation Co., Ltd.)". Specifically, as shown in Figure 1, an image forming apparatus was prepared that includes a cleaning device 22 equipped with a cleaning blade 220 made of polyurethane rubber that contacts the surface of the photoreceptor 12, and a lubricant supply device 64 that supplies the lubricant contained in the lubricant solid 66A to the surface of the photoreceptor 12 via a rotating brush which is a lubricant supply member 66B. The rotating brush has nylon fibers and a fiber density of 70 x 10 3Books / inch 2 (109 pieces / mm 2 The fiber length was 5 mm, the fiber thickness was 15 denier, the ratio Hm / Hf was 0.7, and the amount of fiber penetration into the photoreceptor surface was 1 mm. Then, the obtained lubricant solid was used as the lubricant solid 66A.

[0094] <Rating> (Transcriptional evaluation) Under conditions of 23°C and 55% RH humidity, a solid blue image was formed on embossed paper (Lezac 66, 204gsm) using the image forming apparatus described above, and the color loss of the image formed on the recesses of the embossed paper was visually evaluated. The evaluation criteria were as follows, and the results are shown in Table 2 ("Emboss Transferability" in the table). -Evaluation Criteria- A: No color fading or color change occurred. B: Slight color variation occurs C: No clear color variation occurs, but more color variation occurs than with standard B. D: Clear color variation occurs E: Discoloration occurs

[0095] (Photoreceptor wear evaluation) After evaluating transferability, 5 million charts with an image density of 7.5% were formed, and the difference in photoreceptor film thickness before and after printing was measured using an eddy current film thickness measuring instrument (Fischerscope MMS) to evaluate photoreceptor wear. The results are shown in Table 2 (in Table 2, under "Photoreceptor Wear (μm)").

[0096] <Evaluation of the properties of lubricant solids> (Strength assessment) The strength of the obtained lubricant solid was evaluated as follows. Specifically, the state of lubricant solids under friction stress was investigated using a Haydon friction tester in an environment of 23°C and 55% RH, with the following conditions: indenter: φ0.2 mm sapphire, load: 50 g, travel distance: 5 mm, travel speed: 10 mm / sec, and number of friction cycles: 10 reciprocations. The evaluation criteria were as follows, and the results are shown in Table 2. -Evaluation Criteria- A: No chipping or cracking occurred. B: Chips occurred, but cracks did not occur. C: Chips and cracks occur.

[0097] [Example 2] Except for using 1 part by mass of boron nitride particles (Denka, product name: Spherical Nano-Size BN, number-average primary particle size: 0.5 μm) instead of 1 part by mass of melamine cyanurate particles in the preparation of the lubricant solid, the lubricant solid was prepared and measured, and the image forming apparatus was prepared and evaluated in the same manner as in Example 1.

[0098] [Example 3] In the preparation of the lubricant solid, the lubricant solid was prepared and measured, and the image forming apparatus was prepared and evaluated in the same manner as in Example 1, except that 0.92 parts by mass of melamine cyanurate particles (manufactured by Nissan Chemical Corporation, product name: MC-6000, number average primary particle size: <2 μm) and 0.08 parts by mass of zinc stearate particles (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: Zinc Stearate, 1.5 μm, number average primary particle size: 1.5 μm) were used instead of 1 part by mass of melamine cyanurate particles.

[0099] [Examples 4-7] Except for changing the pressure in compression molding as shown in Table 1, the production and measurement of the lubricant solids, as well as the production and evaluation of the image forming apparatus, were carried out in the same manner as in Example 1.

[0100] [Example 8] Except for the use of 1 part by mass of melamine cyanurate particles (manufactured by Nissan Chemical Corporation, product name: MC-4000, number average primary particle size: <14 μm) instead of 1 part by mass of melamine cyanurate particles (manufactured by Nissan Chemical Corporation, product name: MC-6000, number average primary particle size: <2 μm) in the preparation of the lubricant solid, the preparation and measurement of the lubricant solid, and the preparation and evaluation of the image forming apparatus were carried out in the same manner as in Example 1.

[0101] [Comparative Example 1] Except for using 1 part by mass of zinc stearate particles (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: Zinc Stearate, 1.5 μm, number average primary particle size: 1.5 μm) instead of 1 part by mass of melamine cyanurate particles in the preparation of the lubricant solid, the lubricant solid was prepared and measured, and the image forming apparatus was prepared and evaluated in the same manner as in Example 1.

[0102] [Comparative Example 2] In preparing the lubricant solid, the lubricant solid was prepared and measured, and the image forming apparatus was prepared and evaluated in the same manner as in Example 1, except that instead of 1 part by mass of melamine cyanurate particles (manufactured by Nissan Chemical Corporation, product name: MC-6000, number average primary particle size: <2 μm), 0.9 parts by mass of melamine cyanurate particles (manufactured by Nissan Chemical Corporation, product name: MC-6000, number average primary particle size: <2 μm) and 0.1 parts by mass of zinc stearate particles (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: Zinc Stearate, 1.5 μm, number average primary particle size: 1.5 μm) were used.

[0103] [Comparative Example 3] In the fabrication of the image forming apparatus, the image forming apparatus was fabricated and evaluated in the same manner as in Example 1, except that a solid lubricant was not used.

[0104] [Table 1]

[0105] In the table, "MC" refers to melamine cyanurate, and "ZnSt" refers to zinc stearate.

[0106] [Table 2]

[0107] As shown in Table 2, the image forming apparatus of the example achieves both suppression of wear on the photoreceptor surface and suppression of color fading in images caused by reduced transferability to embossed paper, compared to the image forming apparatus of the comparative example. [Explanation of Symbols]

[0108] 10 Image forming apparatus 12, 207 Photoreceptor 14 Charged members 15. Charging device 16 Electrostatic image forming device 18A Developing material 18, 211 Developing equipment 20 Primary transfer member 22 Cleaning device 24 Static eliminator 26, 228 Fixing device 26A Fixing member 26B Pressurizing member 28, 30, 32, 34 power supply 31 Primary Transfer Apparatus 36 Control device 42,222 Drive Rolls 44,224 support rolls 46 Opposite Roll 48. Secondary transfer device 50, 250 intermediate transfer belt 52 Secondary transfer member 54. Transport Route 64, 264 Lubricant supply device 66A Lubricant Solids 66B Lubricant supply member 77 Leveling member 200 Process Cartridges 208 Electrostatic Roll 209 Exposure equipment 212 Primary Transfer Roll 213 Photoconductor Cleaning Device 216 Mounting Rail 217 cabinets 218 Opening 220 Cleaning Blades 226 Secondary transfer roll 300 sheets of recording paper P recording medium

Claims

1. An electrophotographic photoreceptor having a photosensitive layer, A charging means for charging the surface of the electrophotographic photoreceptor, A means for forming an electrostatic image on the surface of the charged electrophotographic photoreceptor, A developing means containing an electrostatic image developer including an electrostatic image developing toner, and developing the electrostatic image formed on the surface of the electrophotographic photoreceptor as a toner image using the electrostatic image developer, An intermediate transfer body on which the toner image is transferred, A primary transfer means for primary transferring the toner image formed on the surface of the electrophotographic photoreceptor to the surface of the intermediate transfer body, A secondary transfer means for secondarily transferring the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium, A cleaning means having a cleaning member that contacts the surface of the electrophotographic photoreceptor and cleans the surface of the electrophotographic photoreceptor, A lubricant supply means containing a lubricant solid containing melamine cyanurate as a lubricant at a concentration of 100% by mass, and supplying the melamine cyanurate lubricant to the contact position between the cleaning member and the electrophotographic photoreceptor, Equipped with, The cleaning member is a cleaning blade, The lubricant supply means includes a lubricant supply member that contacts the surface of the electrophotographic photoreceptor and supplies the lubricant, which is melamine cyanurate, to the contact position between the cleaning member and the electrophotographic photoreceptor. The image forming apparatus is an image forming apparatus in which the lubricant supply member is a rotating brush having brush fibers with a fiber thickness of 0.5 denier or more and 30 denier or less.

2. The image forming apparatus according to claim 1, wherein the lubricant solid is a compressed molded body of melamine cyanurate particles having a number mean primary particle size of 10 μm or less.

3. The Martens hardness of the aforementioned lubricant solid at 23°C is 24 N / mm². ２ 80N / mm or more ２ The image forming apparatus according to claim 1 or claim 2, which is as follows:

4. The Martens hardness of the aforementioned lubricant solid at 23°C is 30 N / mm². ２ More than 60N / mm ２ The image forming apparatus according to claim 3, which is as follows:

5. An electrophotographic photoreceptor having a photosensitive layer, A charging means for charging the surface of the electrophotographic photoreceptor, A cleaning means having a cleaning member that contacts the surface of the electrophotographic photoreceptor and cleans the surface of the electrophotographic photoreceptor, A lubricant supply means containing a lubricant solid containing melamine cyanurate as a lubricant at a concentration of 100% by mass, and supplying the melamine cyanurate lubricant to the contact position between the cleaning member and the electrophotographic photoreceptor, Equipped with, The cleaning member is a cleaning blade, The lubricant supply means includes a lubricant supply member that contacts the surface of the electrophotographic photoreceptor and supplies the lubricant, which is melamine cyanurate, to the contact position between the cleaning member and the electrophotographic photoreceptor. The lubricant supply member is a rotating brush having brush fibers with a fiber thickness of 0.5 denier or more and 30 denier or less. A process cartridge that is attached to and detached from an image forming apparatus using an intermediate transfer method.

Images