Process cartridge and process cartridge set

Abstract

To provide a cartridge in which a harmful effect caused by contamination of a conductive member hardly occurs.SOLUTION: (I) A conductive layer of charging means has a matrix-domain structure, and when a Martens hardness of the matrix is defined as G1 and a Martens hardness of the domain as G2, G1 and G2 are 1.0 N / mm2 or more and 10.0 N / mm2 or less, and an absolute value of a difference between G1 and G2 is 0.1 N / mm2 or more and 7.0 N / mm2 or less. (II) A number ratio CI of toner particles having aggregates on particle surfaces is 1 number% or more and 15 number% or less, and when a number ratio of particles having aggregates in toner after processing under a condition A is defined as Ca (number%) and a number ratio of particles having aggregates in the toner after processing under a condition B as Cb (number%), the following formulas are satisfied. An arithmetic mean value Dms of distances between adjacent domains and an arithmetic mean value Ag of Feret's diameters of the aggregates satisfy a relation of Dms<Ag. 0.90≤Ca / CI≤1.00, and 0.01≤Cb / CI≤0.10.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a process cartridge and a process cartridge set used in a recording method using an electrophotographic method, an electrostatic recording method, and a toner jet recording method.

Background Art

[0002] Methods for visualizing image information through an electrostatic latent image, such as the electrophotographic method, are applied to copiers, multifunction printers, and printers. In recent years, with the diversification of usage purposes, further extension of the service life and improvement of image quality of electrophotographic main bodies and process cartridges have been demanded. In addition, in order to maintain high image quality throughout the life, it is effective to control the chargeability of the toner so that it does not change throughout the life. In a normal electrophotographic process, the chargeability of the toner is controlled by disposing various organic or inorganic fine powders, commonly called external additives, on the toner surface. Consideration has also been given to using aggregates rather than single particles as external additives. For example, Patent Document 1 discloses a toner that can achieve high image quality even in a high-temperature and high-humidity environment by using aggregates of silica. In addition, a conductive member is used as a charging member in an electrophotographic apparatus. As the conductive member, a configuration having a conductive support and a conductive layer provided on the support is known. The conductive member transports charges from the conductive support to the surface of the conductive member and plays a role of giving charges to an abutting object by discharge or triboelectrification. The conductive member as a charging member is a member that generates a discharge between the electrophotographic photoreceptor and charges the surface of the electrophotographic photoreceptor. When the surface of the charging member, which is a conductive member, is contaminated by an external additive or toner that is an insulator, the chargeability of the contaminated part changes and becomes apparent in the image. Therefore, a cleaning member may be attached for the purpose of removing toner and external additives on the electrophotographic photoreceptor to suppress contamination of the charging member. In this cleaning part, there is a layer called a blocking layer formed by supplying an external additive between the cleaning member and the electrophotographic photoreceptor, and it is known that the cleaning property is exhibited by this blocking layer. For such a conductive member, for example, in Patent Document 2, attempts are disclosed to provide high-quality images by controlling the surface irregularities of the conductive member to a desired shape and selecting the content of the external additive contained in the toner to control the surface contamination of the charging member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, in order to achieve high image quality throughout a long life, various toners having external additives and cartridges using conductive members have been proposed so far. On the other hand, it is also known that there are adverse effects due to the external additive contaminating the member. For example, when paper dust or foreign matter in the main body reaches the cleaning unit, if a part of the blocking layer in the cleaning unit is damaged, the cleaning property in that area is lost, so a phenomenon occurs in which a large amount of toner and external additive are supplied to the conductive member until the blocking layer is reformed. When this phenomenon occurs, a part of the conductive member is extremely contaminated, resulting in image defects as vertical streaks. This phenomenon is prominent when the external additive is designed in a small amount for another purpose or when the blocking layer is thinned. On the other hand, even when the external additive is designed to be large so that a large amount of the external additive comes to the cleaning unit and the blocking layer is maintained, some of the external additive may pass through the cleaning unit and contaminate the conductive member. When this phenomenon occurs, the entire conductive member is sparsely contaminated, resulting in uneven potential on the photoreceptor, and there may be an adverse effect of uneven image density. These problems can become more prominent in long-life electrophotographic systems where contamination continues to accumulate simply by adjusting the amount of the additive. From this perspective, in the technologies described in Patent Document 1 and Patent Document 2, there was room for further improvement regarding image defects associated with contamination of the conductive member in longer-life electrophotographic systems. In view of these problems, the present disclosure provides a cartridge in which image defects due to poor cleaning and contamination of the conductive member are less likely to occur over a long life, and high image quality over a long life can be achieved.

Means for Solving the Problems

[0005] The present invention is a process cartridge having a toner, a toner container for containing the toner, an electrophotographic photoreceptor, charging means for charging the surface of the electrophotographic photoreceptor, cleaning means for removing residual toner in a region upstream of the charging means, and developing means for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor with toner to form a toner image on the surface of the electrophotographic photoreceptor, (I) The charging means has a conductive member disposed so as to be contactable with the electrophotographic photoreceptor, The cleaning means has a cleaning blade disposed so as to be contactable with the electrophotographic photoreceptor, The conductive member has a support having a conductive outer surface and a conductive layer provided on the outer surface of the support, the conductive layer having a matrix-domain structure having a matrix and a plurality of domains dispersed in the matrix, the matrix containing a first rubber, the domain containing a second rubber, and the surface of the conductive member having a surface roughness Ra of 2.00 μm or less on the surface, When the Martens hardness measured at a load of 1 mN in the matrix of the outer surface of the conductive member is G1 and the Martens hardness measured at a load of 1 mN in the domain of the outer surface of the conductive member is G2, both G1 and G2 are within the range of 1.0 N / mm 2 or more and 10.0 N / mm 2 or less, and the absolute value of the difference between G1 and G2 is 0.1 N / mm2 7.0 N / mm or more 2 is below, (II) The toner has at least toner particles, and agglomerates containing silica fine particles and a binder component are present on the surface of the toner particles, when the number ratio of the toner particles having the agglomerates is defined as CI (number %), the CI is 1 number % or more and 15 number % or less, when the number ratio of the toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition A is defined as Ca (number %), and the number ratio of the toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition B is defined as Cb (number %), the CI, the Ca, and the Cb satisfy the formulas (1) and (2), · Ultrasonic condition A: Output frequency 30 kHz, output power 0.75 W, irradiation time 300 s · Ultrasonic condition B: Output frequency 30 kHz, output power 35 W, irradiation time 300 s 0.90 ≦ Ca / CI ≦ 1.00 Formula (1) 0.01 ≦ Cb / CI ≦ 0.10 Formula (2) A process cartridge characterized in that the arithmetic mean value Dms of the adjacent distances of the domains present on the outer surface of the conductive roller and the arithmetic mean value Ag of the Feret diameters of the agglomerates satisfy the relationship Dms < Ag. Further, the present invention is a process cartridge set having a first cartridge and a second cartridge that are detachable from the main body of an electrophotographic apparatus, (I) The first cartridge has a charging means for charging the surface of the electrophotographic photoreceptor, a cleaning means for removing residual toner in a region upstream of the charging means, and a first frame for supporting the charging means and the cleaning means, The second cartridge has a toner container that houses toner for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor to form a toner image on the surface of the electrophotographic photoreceptor, (II) The charging means has a conductive member disposed in contact with the electrophotographic photoreceptor, The cleaning means has a cleaning blade disposed in contact with the electrophotographic photoreceptor, The conductive member has a support having a conductive outer surface and a conductive layer provided on the outer surface of the support, the conductive layer having a matrix-domain structure having a matrix and a plurality of domains dispersed in the matrix, the matrix containing a first rubber, the domains containing a second rubber, and the surface of the conductive member having a surface roughness Ra of 2.00 μm or less on the surface. When the Martens hardness measured at a load of 1 mN in the matrix of the outer surface of the conductive member is G1 and the Martens hardness measured at a load of 1 mN in the domain of the outer surface of the conductive member is G2, both G1 and G2 are in the range of 1.0 N / mm 2 or more and 10.0 N / mm 2 or less, and the absolute value of the difference between G1 and G2 is 0.1 N / mm 2 or more and 7.0 N / mm 2 or less. (III) The toner has at least toner particles, and agglomerates containing silica fine particles and a binder component are present on the surface of the toner particles. When the number ratio of the toner particles having the agglomerates is CI (number %), the CI is 1% or more and 15% or less by number. When the number ratio of the toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition A is Ca (number %) and the number ratio of the toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition B is Cb (number %), the CI, the Ca, and the Cb satisfy the formulas (1) and (2). · Ultrasonic condition A: Output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s · Ultrasonic condition B: Output frequency 30 kHz, output capacity 35 W, irradiation time 300 s 0.90 ≦ Ca / CI ≦ 1.00 Formula (1) 0.01 ≦ Cb / CI ≦ 0.10 Formula (2) A process cartridge set characterized in that the arithmetic mean value Dms of the adjacent distances between the domains present on the outer surface of the conductive roller and the arithmetic mean value Ag of the Feret diameters of the agglomerates satisfy the relationship Dms < Ag.

Advantages of the Invention

[0006] According to the present invention, there is provided a process cartridge that is less likely to cause image defects due to poor cleaning and contamination of conductive members throughout its long life, and can achieve high image quality with a long life.

Brief Description of the Drawings

[0007]

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Figure 10

Embodiments for Carrying Out the Invention

[0008] In the present disclosure, unless otherwise specified, the description of "XX or more and YY or less" or "XX to YY" representing a numerical range means a numerical range including the lower limit and the upper limit which are the endpoints. When numerical ranges are described stepwise, the upper and lower limits of each numerical range can be arbitrarily combined. Further, in the following description, the toner particles before the presence of agglomerates on the surface of the toner particles may be referred to as "toner core particles".

[0009] 〔Features of the present invention〕 As described above, as an external additive for toner, the ability to stably form a blocking layer in the cleaning unit and the ability to be difficult to pass through the cleaning unit or, even if passing through, to be difficult to adhere to the conductive member are required.

[0010] As a means for stably forming a blocking layer, it is conceivable to supply a large amount of the external additive to the blocking layer. By supplying a large amount of the external additive, it is considered that a blocking layer made of a large amount of the external additive is formed, and a strong blocking layer that is difficult for the toner to pass through is formed. Further, if a large amount of the external additive can be supplied, it is considered that the blocking layer can be quickly reformed even if the blocking layer is destroyed.

[0011] However, supplying a large amount of the external additive means that the external additive easily migrates from the toner to the member, so it is likely to cause member contamination and the external additive is also likely to pass through the cleaning unit. Further, when the external additive easily migrates from the toner to the member, the external additive is consumed at an initial stage, and it is difficult to maintain the effect throughout the long life.

[0012] Therefore, in order to maintain high cleaning performance throughout a longer life, a toner is required that forms a strong blocking layer without relying on a large amount of the external additive, does not supply a large amount of the external additive when the blocking layer is stable, and can quickly supply a large amount of the external additive to reform the blocking layer in a situation such as when the blocking layer is destroyed.

[0013] With respect to these required characteristics, the present inventors have found that a combination of the following toner and a conductive member as a charging member is less likely to cause cleaning defects and image defects due to conductive member contamination throughout a long life, and can provide high-quality electrophotographic images.

[0014] "Toner" The toner has at least toner particles, and agglomerates containing silica fine particles and a binder component are present on the surface of the toner particles. When the number ratio of the toner particles having the agglomerates is defined as CI (number %), the CI is 1% to 15% by number. When the number ratio of the toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition A is defined as Ca (number %), and the number ratio of the toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition B is defined as Cb (number %), the CI, the Ca, and the Cb satisfy the formulas (1) and (2). · Ultrasonic condition A: Output frequency 30 kHz, output power 0.75 W, irradiation time 300 s · Ultrasonic condition B: Output frequency 30 kHz, output power 35 W, irradiation time 300 s 0.90 ≦ Ca / CI ≦ 1.00 Formula (1) 0.01 ≦ Cb / CI ≦ 0.10 Formula (2) The arithmetic mean value Dms of the adjacent distances between the domains present on the outer surface of the conductive roller and the arithmetic mean value Ag of the Feret diameters of the agglomerates satisfy the relationship Dms < Ag.

[0015] "Conductive member" The conductive member (hereinafter also referred to as a conductive roller) has a support having a conductive outer surface and a conductive layer provided on the outer surface of the support, and the conductive layer has a matrix-domain structure having a matrix and a plurality of domains dispersed in the matrix. The matrix contains a first rubber, the domains contain a second rubber, and the surface of the conductive member has a surface roughness Ra of 2.00 μm or less. Let G1 be the Martens hardness measured at a load of 1 mN in the matrix on the outer surface of the conductive roller, and G2 be the Martens hardness measured at a load of 1 mN in the domain on the outer surface of the conductive roller. When both G1 and G2 are within the range of 2 10.0 N / mm 2 or more and 2 7.0 N / mm 2 or less, and the absolute value of the difference between G1 and G2 is within the range of

[0016] The inventors of the present invention consider the mechanism by which this combination achieves the effect as follows.

[0017] The toner of the present disclosure has agglomerates containing silica fine particles and a binder component on the surface of the toner particles. Since the agglomerates have silica fine particles or a binder component that connects the toner and the agglomerates, unlike ordinary aggregates of silica fine particles, it is difficult for the silica fine particles and the toner and the agglomerates to separate from each other. Therefore, it is considered that a strong blocking layer can be formed when supplied to the blocking layer. Therefore, it is considered that it is difficult for the external additive to pass through, and it is difficult for the image density unevenness associated with the contamination of the conductive roller described above to occur.

[0018] When the blocking layer is broken, the toner passes through the cleaning unit and reaches the conductive member. If this state continues, a large amount of toner and external additive will accumulate on the conductive member, resulting in image defects. To solve this problem, the inventors of the present invention considered that when the toner reaches the conductive member, the external additive present on the toner is quickly transferred from the toner to the photoreceptor, and the external additive can be quickly supplied to the cleaning unit.

[0019] In the toner of the present disclosure, when the number ratio of toner particles having the agglomerates is defined as CI (number %), the CI is 1% by number or more and 15% by number or less. When the number ratio of toner particles having the agglomerates in the toner after being processed under the following ultrasonic condition A is defined as Ca (number %), and the number ratio of toner particles having the agglomerates in the toner after being processed under the following ultrasonic condition B is defined as Cb (number %), the CI, the Ca, and the Cb satisfy 0.90 ≤ Ca / CI ≤ 1.00 Formula (1) 0.01 ≤ Cb / CI ≤ 0.10 Formula (2) That is, it does not transfer from the toner in an environment with a low share, and has the characteristic of transferring from the toner in an environment with a high share. By having this characteristic, in a limited situation where the blocking layer is broken and toner leakage occurs, agglomerates can transfer from the toner and quickly reform the blocking layer, and it is considered that image defects can be suppressed.

[0020] Furthermore, by combining with a conductive roller as shown below, it is considered that this problem can be solved because the agglomerates present on the surface of the toner particles of the present disclosure can be very efficiently transferred onto the photosensitive drum.

[0021] The conductive roller in the present disclosure has a surface roughness Ra of the outer surface of 2.00 μm or less. Further, in the matrix of the conductive layer having a matrix-domain structure on the outer surface of the conductive roller, when the Martens hardness measured at a load of 1 mN is defined as G1, and the Martens hardness measured at a load of 1 mN in the domain is defined as G2, both G1 and G2 are within the range of 1.0 N / mm 2 or more and 10.0 N / mm 2 or less, and the absolute value of the difference between G1 and G2 is 0.1 N / mm 2 or more and 7.0 N / mm 2It satisfies the following characteristics. Furthermore, for the agglomerates, the arithmetic mean value Dms of the closest distances between domains on the outer surface of the conductive roller and the arithmetic mean value Ag of the Feret diameters of the agglomerates satisfy the relationship Dms < Ag. The above G1 and G2 indicate that there are regions with different hardnesses on the outer surface of the conductive roller. The fact that the conductive roller and the agglomerates satisfy these characteristics means that when the agglomerates come into contact with the conductive roller, they can exist across regions with different hardnesses on the surface of the conductive roller.

[0022] When pressure is applied across such regions with different hardnesses, the region with lower hardness deforms, so the pressure escapes. On the other hand, the region with higher hardness does not deform. Therefore, a phenomenon occurs where the pressure is pseudo-concentrated in the region with higher hardness, resulting in an increase in the peak pressure. Therefore, because the agglomerates exist across regions with different hardnesses on the surface of the conductive roller, it is considered that the pressure applied from the conductive member to the agglomerates is higher than that of ordinary external additives. That is, when toner reaches the nip portion of the conductive roller and the photoreceptor, and a high share is applied to the agglomerates present on the surface of the toner, it is considered that the agglomerates migrate from the toner to the surface of the photoreceptor. For this reason, it is presumed that only in a temporary environment when the toner passes through the cleaning unit, a large amount of external additive is supplied to the photoreceptor by the migrated agglomerates, and the blocking layer can be quickly restored before image defects occur.

[0023] As described above, with the combination of the present case, in a portion with a low share such as the cleaning unit, a strong blocking layer is formed. On the other hand, after passing through the cleaning unit, the agglomerates can preferably migrate by contact with the conductive member to reform the blocking layer.

[0024] Hereinafter, based on the above mechanism, the configuration and preferred range of the present disclosure will be described in detail. The description of the overall configuration of the process cartridge will be described later.

[0025] 〔Conductive Roller〕 As an example of a conductive member, a conductive roller having a roller shape (hereinafter also referred to as a "conductive member") will be described with reference to FIG. 1. FIG. 1 is a cross-sectional view perpendicular to the direction along the axis of the conductive roller (hereinafter also referred to as the "longitudinal direction"). The conductive roller 51 has a columnar conductive support 52 and a conductive layer 53 formed on the outer circumference of the support 52, that is, on the outer surface of the support.

[0026] <Support> As the material constituting the support, it can be appropriately selected and used from those known in the field of electrophotographic conductive rollers and materials that can be used as conductive rollers. As an example, metals or alloys such as aluminum, stainless steel, conductive synthetic resin, iron, and copper alloy can be mentioned.

[0027] Furthermore, these may be subjected to oxidation treatment or plating treatment with chromium, nickel, etc. As the type of plating, either electroplating or electroless plating can be used. Electroless plating is preferred from the viewpoint of dimensional stability. As the types of electroless plating used here, nickel plating, copper plating, gold plating, and various other alloy platings can be mentioned.

[0028] The plating thickness is preferably 0.05 μm or more, and considering the balance between working efficiency and rust prevention ability, the plating thickness is preferably 0.10 μm or more and 30.00 μm or less. The columnar shape of the support may be a solid columnar shape or a hollow columnar shape (cylindrical shape). Also, the outer diameter of the support is preferably in the range of 3 mm or more and 10 mm or less.

[0029] If there is an intermediate resistance layer or an insulating layer between the support and the conductive layer, the supply of charges after the consumption of charges due to discharge may not be able to be carried out quickly. Therefore, it is preferable that the conductive layer is provided directly on the support or the conductive layer is provided on the outer circumference of the support only through an intermediate layer made of a thin and conductive resin layer such as a primer.

[0030] As the primer, a known one can be selected and used according to the rubber material for forming the conductive layer, the material of the support, etc. Examples of the primer material include thermosetting resins and thermoplastic resins. Specifically, known materials such as phenolic resins, urethane resins, acrylic resins, polyester resins, polyether resins, and epoxy resins can be used.

[0031] <Conductive layer> The conductive layer has a matrix and a plurality of domains dispersed in the matrix. The matrix contains a first rubber, and the domains contain a second rubber and, if necessary, an electron conductive agent. The electron conductive agent is preferably contained in the domains in terms of favorably transferring the agglomerates of the external additive, but may be contained in the matrix as long as the charging function of the conductive roller is not impaired.

[0032] In addition, the conductive layer according to the present invention needs to satisfy the following components (i) and (ii), and preferably satisfies the following component (iii). Component (i): The surface roughness Ra of the outer surface of the conductive roller is 2.00 μm or less. Component (ii): The Martens hardness G1 measured at a load of 1 mN for the matrix portion and the Martens hardness G2 measured at a load of 1 mN for the domain portion are such that both G1 and G2 are in the range of 1.0 N / mm 2 or more and 10.0 N / mm 2 or less, and the absolute value of the difference between G1 and G2 satisfies the relationship of being 2 0.1 N / mm or more and 7.0 N / mm 2 or less. Component (iii): The arithmetic mean value Dm of the distances between adjacent wall surfaces of the domains (hereinafter also simply referred to as "domain distance Dm") in the cross-sectional observation in the thickness direction of the conductive layer is 2.00 μm (2000 nm) or less.

[0033] [Component (i): Surface roughness Ra of the conductive layer] The surface roughness Ra of the outer surface of the conductive roller needs to be 2.00 μm or less. If the surface roughness Ra is 2.00 μm or less, the contact area between the conductive roller and the photosensitive drum increases, and the chance of contact with the toner reaching the surface of the conductive roller can be increased. Therefore, a suitable share can be given to the agglomerates, and the performance of transferring onto the photosensitive drum can be improved. Furthermore, since the area of the concave portions where toner and external additives tend to accumulate on the surface of the conductive roller is reduced, it becomes difficult for the external additives to remain on the surface of the conductive roller, and image defects are less likely to occur. On the other hand, if Ra is greater than 2.00 μm, part of the agglomerates remains in the concave portions, contaminating the conductive roller, and image defects are likely to occur.

[0034] The surface roughness Ra is preferably 1.00 μm or less. The lower limit is not particularly limited, but is preferably 0.30 μm or more, more preferably 0.60 μm or more. The surface roughness Ra can be appropriately adjusted, for example, by the selection of the materials constituting the domain and the matrix, and the polishing conditions.

[0035] The method for measuring the surface roughness Ra will be described later.

[0036] [Component (ii): Martens hardness] On the outer surface of the conductive roller, at least a part of a plurality of domains dispersed in the matrix is exposed. Therefore, the outer surface of the conductive roller is composed of the matrix and the exposed portions of the domains. Then, when a indenter is brought into contact with the matrix exposed on the outer surface of the conductive roller, and the Martens hardness obtained by the method described later is defined as G1, and the indenter is brought into contact with the domains exposed on the outer surface of the conductive roller, and the Martens hardness obtained by the method described later is defined as G2, G1 and G2 satisfy the above-mentioned relationship.

[0037] The Martens hardnesses G1 and G2 are not parameters representing the hardness of the matrix as a bulk and the hardness of the domains as a bulk, but are parameters representing the hardness of the conductive layer in the matrix portion and the exposed portion of the domains forming the outer surface of the conductive layer.

[0038] That is, the Martens hardness measured from the outer surface of the conductive layer defines the pressure received when the external additive and toner located on the outer surface are pressed in the nip formed by the electrophotographic photoreceptor and the conductive roller.

[0039] Here, the fact that G1 and G2 satisfy the above-described relationship means that the hardness of the outer surface of the conductive roller is not uniform. Due to this, the agglomerates that have come into contact with the outer surface are considered to be likely to transfer from the toner by receiving a high share in the hard regions in the situation across the domains and the matrix as described above.

[0040] G1 is preferably 1.0 N / mm 2 or more and 8.0 N / mm 2 or less, more preferably 1.8 N / mm 2 or more and 7.0 N / mm 2 or less. G2 is preferably 1.5 N / mm 2 or more and 10.0 N / mm 2 or less, more preferably 2.2 N / mm 2 or more and 8.0 N / mm 2 or less. Further, the absolute value of the difference between G1 and G2 is preferably 0.3 N / mm 2 or more and 6.0 N / mm 2 or less.

[0041] The Martens hardnesses G1 and G2 can be controlled, for example, by the material of the first rubber constituting the matrix, the degree of crosslinking of the first rubber, the type of additive in the matrix, the amount of the additive, the material of the second rubber constituting the domain, the degree of crosslinking of the second rubber, the amount of the electron conductive agent in the domain, and the abundance ratio of the domains in the matrix.

[0042] G1 and G2 are preferably controlled mainly by the crosslinking degree of the rubber. Specifically, while setting G1 and G2 within the above ranges, the crosslinking degree of the rubber is adjusted by the types and addition amounts of the vulcanizing agent and the vulcanization accelerator. As the vulcanizing agent, for example, sulfur is used. The amount of sulfur is preferably adjusted appropriately according to the type and amount of the rubber used. It is preferably 0.5 parts by mass or more and 8.0 parts by mass or less with respect to 100 parts by mass of the rubber component in the unvulcanized rubber composition. By setting the amount of sulfur to 0.5 parts by mass or more, the vulcanized product can be sufficiently cured. Also, by setting the amount of sulfur to 8.0 parts by mass or less, it is possible to suppress the crosslinking of the vulcanized product from becoming too high and the hardness from becoming too high.

[0043] Examples of the vulcanization accelerator include thiuram-based, thiazole-based, guanidine-based, sulfenamide-based, dithiocarbamate-based, thiourea-based, etc. Among them, the thiuram-based vulcanization accelerator is preferable because it has a high effect as a vulcanization accelerator for the vulcanization of the first rubber and the second rubber and it is easy to adjust G1 and G2.

[0044] Examples of the thiuram-based vulcanization accelerator include tetramethylthiuram disulfide (TT), tetraethylthiuram disulfide (TET), tetrabutylthiuram disulfide (TBTD), tetraoctylthiuram disulfide (TOT), etc.

[0045] As the content of the vulcanization accelerator in the unvulcanized rubber composition, it is preferably 0.5 parts by mass or more and 4.0 parts by mass or less with respect to 100 parts by mass of the rubber component in the unvulcanized rubber composition. When it is 0.5 parts by mass or more, a sufficient effect as a vulcanization accelerator can be obtained. Also, when it is 4.0 parts by mass or less, vulcanization is not promoted too much and it is easy to keep G1 and G2 within the above ranges.

[0046] Furthermore, as a means for adjusting G1 and G2, the addition amount of an electron conductive agent can be mentioned. Examples of the electron conductive agent incorporated into the domain include oxides such as carbon black, graphite, titanium oxide, and tin oxide; metals such as Cu and Ag; and particles coated with an oxide or metal on the surface and made conductive. Also, if necessary, two or more of these conductive agents may be blended in appropriate amounts and used.

[0047] Among the above electron conductive agents, it is preferable to use conductive carbon black that has a large affinity with the rubber and can further impart reinforcing properties to the rubber. The type of carbon black incorporated into the domain is not particularly limited. Specifically, for example, gas furnace black, oil furnace black, thermal black, lamp black, acetylene black, ketjen black, etc. can be mentioned.

[0048] For the purpose of adjusting G1 and G2, the content of an electron conductive agent such as carbon black is preferably 20 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the second rubber contained in the domain. More preferably, it is 50 parts by mass or more and 100 parts by mass or less. Within this range, it is possible to obtain the effects of this case while maintaining the conductivity of the conductive member.

[0049] [Component (iii): Distance between adjacent wall surfaces of the domain] When an aggregate present on the surface of the toner particles comes into contact with the surface of the conductive roller, in order to suitably apply a peak pressure for transferring the aggregate to the surface of the photoreceptor, it is preferable that the adjacent distance of the domains present on the outer surface of the conductive roller satisfies the following range.

[0050] Specifically, since a configuration that crosses the boundary between domains and the matrix with different hardnesses is required for the aggregate on the surface of the toner particles, the arithmetic mean value Dms of the adjacent distance of the domains present on the outer surface of the conductive roller is preferably 2.00 μm or less, and more preferably 1.00 μm or less.

[0051] The method for manufacturing the conductive layer will be described later. Since the conductive roller kneads and molds the conductivity uniformly, the domain-matrix structure on the outer surface has the same structure as the domain-matrix structure inside the conductive layer. Therefore, the adjacent distance between domains existing on the outer surface of the conductive roller may be set to preferably 2.00 μm or less, more preferably 1.00 μm or less, which is the arithmetic mean value Dm of the distance between adjacent wall surfaces of the domains in the cross-sectional observation in the thickness direction of the conductive layer.

[0052] In addition, since the contact opportunity between the domain and the matrix boundary can be improved for the agglomerates on the toner particle surface, the domain distance Dm is preferably 0.15 μm or more, more preferably 0.20 μm or more. Within this range, the domains can be surely electrically separated by the insulating region (matrix), and the effect of making it easier to accumulate charges in the domains can also be expected.

[0053] · Method for measuring the adjacent wall surface distance Dm of the domain; The method for measuring the domain distance Dm may be carried out as follows.

[0054] First, a section is prepared in the same manner as the method for measuring the volume resistivity of the matrix. In addition, in order to preferably observe the matrix-domain structure, pretreatment such as staining treatment and vapor deposition treatment may be performed to preferably obtain a contrast between the conductive phase and the insulating phase.

[0055] The section formed with a fracture surface and platinum vapor deposition is observed by a scanning electron microscope (SEM) to confirm the existence of the matrix-domain structure. Among these, from the accuracy of quantifying the area of the domain, it is preferable to observe with SEM at 5000 times magnification. The specific procedure will be described later.

[0056] · Uniformity of the adjacent wall surface distances Dms and Dm of the domain; Since a constant peak pressure is always applied to the agglomerates on the surface of the toner particles, and the state that changes depending on the contact location can be suppressed, it is preferable that the distribution of the adjacent inter-domain distance Dms of the domains present on the surface of the conductive roller is uniform. Also, from the viewpoint of discharge characteristics, it is preferable that the distribution of the inter-domain distance Dm is uniform because microdischarges can be formed more stably. When the distribution of the inter-domain distance Dm is uniform, a part where the inter-domain distance is locally long can be formed within the conductive layer, and when a location where the supply of charges is delayed compared to the surroundings occurs, the phenomenon of non-uniform discharge can be suppressed.

[0057] In the cross-section through which charges are transported, that is, in the cross-section in the thickness direction of the conductive layer as shown in Fig. 3(b), three arbitrary 50-μm square observation regions are acquired at depths of 0.1T to 0.9T from the outer surface of the conductive layer toward the support. At this time, using the inter-domain distance Dm within the observation region and the standard deviation σm of the distribution of the inter-domain distance, it is preferable that the coefficient of variation σm / Dm of the inter-domain distance is 0 or more and 0.40 or less, and more preferably 0.10 or more and 0.30 or less.

[0058] · Method for measuring the uniformity of the adjacent wall surface distances Dms and Dm of the domains; The measurement of the uniformity of the inter-domain distance can be performed by quantifying an image obtained by directly observing the fracture surface, similar to the measurement of the inter-domain distance. The specific procedure will be described later.

[0059] The conductive member according to the present invention can be formed, for example, through a method including the following steps (i) to (iv).

[0060] Step (i): A step of preparing a rubber mixture for domain formation (hereinafter also referred to as "CMB") containing carbon black and a second rubber; Step (ii): A step of preparing a rubber mixture for matrix formation (hereinafter also referred to as "MRC") containing a first rubber; Step (iii): A step of kneading CMB and MRC to prepare a rubber mixture having a matrix-domain structure. Step (iv): Forming a layer of the rubber mixture prepared in step (iii) directly on a conductive support or via another layer, and curing the layer of the rubber composition to form a conductive layer.

[0061] And the above-described components (i) to (iii) can be controlled, for example, by selecting the materials used in each of the above steps and adjusting the manufacturing conditions.

[0062] <Method for Confirming Domain Matrix Structure> The presence of the domain matrix structure in the conductive layer can be confirmed by preparing a thin slice from the conductive layer and observing in detail the fracture surface formed on the thin slice. Specific procedures will be described later.

[0063] <Control of Domain Dispersion State> Regarding the dispersion state of the domains, it is effective to control the following four items (a) to (d).

[0064] (a) Difference in the interfacial tension σ between each of CMB and MRC (b) Ratio (ηd / ηm) of the viscosity (ηd) of CMB to the viscosity (ηm) of MRC (c) Shear rate (γ) and energy amount during shear (EDK) during kneading of CMB and MRC in the above step (iii) (d) Volume fraction of CMB with respect to MRC in the above step (iii)

[0065] (a) Interfacial tension difference between CMB and MRC: Generally, when two kinds of incompatible rubbers are mixed, phase separation occurs. This is because the interaction between the same polymers is stronger than the interaction between different polymers, so the same polymers aggregate with each other to reduce the free energy and stabilize.

[0066] Since the interface of the phase separation structure comes into contact with different polymers, the free energy is higher than that of the interior stabilized by the interaction between like molecules. As a result, in order to reduce the free energy of the interface, an interfacial tension is generated to reduce the area of contact with different polymers. When this interfacial tension is small, it tends to move in the direction of more uniform mixing even of different polymers in order to increase entropy. The state of uniform mixing is dissolution, and the SP value (solubility parameter), which is a measure of solubility, and the interfacial tension tend to be correlated.

[0067] That is, the interfacial tension difference between CMB and MRC is considered to be correlated with the difference in the SP values of the rubbers contained in each. The absolute value difference between the solubility parameter SP value of the first rubber in MRC and the SP value of the second rubber in CMB is preferably 0.4 (J / cm 3 ) 0.5 or more and 5.0 (J / cm 3 ) 0.5 or less, more preferably 0.4 (J / cm 3 ) 0.5 or more and 2.2 (J / cm 3 ) 0.5 or less. It is preferable to select rubbers such that the range is within this range. A stable phase separation structure can be formed within this range, and the domain diameter of CMB can be reduced.

[0068] Here, as specific examples of the second rubber that can be used for CMB, for example, at least one selected from the group consisting of natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), acrylonitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), butyl rubber (IIR), ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), chloroprene rubber (CR), nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), silicone rubber, and urethane rubber (U) is preferable.

[0069] It is more preferable that the second rubber is at least one selected from the group consisting of styrene-butadiene rubber (SBR), butyl rubber (IIR), and acrylonitrile-butadiene rubber (NBR), and it is even more preferable that it is at least one selected from the group consisting of styrene-butadiene rubber (SBR) and butyl rubber (IIR).

[0070] The thickness of the conductive layer is not particularly limited as long as the functions and effects of the intended conductive roller can be obtained. The thickness of the conductive layer is preferably 1.0 mm or more and 4.5 mm or less.

[0071] The mass ratio of the domain to the matrix (domain:matrix) is preferably 5:95 to 40:60, more preferably 10:90 to 30:70, and even more preferably 13:87 to 25:75.

[0072] ·Method for measuring SP value The SP value can be accurately calculated by creating a calibration curve using a material with a known SP value. As this known SP value, the catalog value of the material manufacturer can also be used. For example, for NBR and SBR, regardless of the molecular weight, the SP value is almost determined by the content ratios of acrylonitrile and styrene.

[0073] Therefore, analyze the content ratios of acrylonitrile or styrene for the rubbers constituting the matrix and the domain using analytical methods such as pyrolysis gas chromatography (Py-GC) and solid NMR. Thereby, the SP value can be calculated from the calibration curve obtained from materials with known SP values.

[0074] Also, for isoprene rubber, the SP value is determined by the isomeric structure such as 1,2-polyisoprene, 1,3-polyisoprene, 3,4-polyisoprene, cis-1,4-polyisoprene, and trans-1,4-polyisoprene. Therefore, similar to SBR and NBR, analyze the isomer content ratio by Py-GC and solid NMR, etc., and calculate the SP value from materials with known SP values.

[0075] The SP values of materials with known SP values are those determined by the Hansen sphere method.

[0076] (b) Viscosity ratio of CMB to MRC: The closer the viscosity ratio of CMB to MRC (CMB / MRC) (ηd / ηm) is to 1, the smaller the domain diameter can be. Specifically, the viscosity ratio is preferably 1.0 or more and 2.0 or less. The viscosity ratio of CMB to MRC can be adjusted by selecting the Mooney viscosity of the raw rubber used for CMB and MRC, and by blending the type and amount of the filler.

[0077] Also, it is possible by adding a plasticizer such as paraffin oil to the extent that it does not prevent the formation of the phase separation structure. Also, the viscosity ratio can be adjusted by adjusting the temperature during kneading.

[0078] Note that the viscosity of the rubber mixture for domain formation and the rubber mixture for matrix formation is the Mooney viscosity ML (1+4) obtained by measuring at the rubber temperature during kneading.

[0079] (c) Shear rate during kneading of MRC and CMB, and energy amount during shear: The faster the shear rate during kneading of MRC and CMB, and the greater the energy amount during shear, the smaller the inter-domain distances Dm and Dms can be.

[0080] The shear rate can be increased by increasing the inner diameter of the stirring member such as the blade or screw of the kneader, decreasing the gap from the end face of the stirring member to the inner wall of the kneader, or increasing the rotation speed. Also, to increase the energy during shear, it can be achieved by increasing the rotation speed of the stirring member or increasing the viscosities of the first rubber in CMB and the second rubber in MRC.

[0081] (d) Volume fraction of CMB with respect to MRC: The volume fraction of CMB with respect to MRC correlates with the probability of collision and coalescence of the rubber mixture for domain formation with respect to the rubber mixture for matrix formation. Specifically, reducing the volume fraction of the rubber mixture for domain formation with respect to the rubber mixture for matrix formation decreases the probability of collision and coalescence of the rubber mixture for domain formation and the rubber mixture for matrix formation. That is, within the range where the required conductivity can be obtained, by reducing the volume fraction of domains in the matrix, the inter-domain distances Dm and Dms can be decreased.

[0082] And the volume fraction of CMB with respect to MRC (that is, the volume fraction of domains with respect to the matrix) is preferably 15% or more and 40% or less.

[0083] <Volume resistivity R1 of the matrix and volume resistivity R2 of the domain> When using the conductive roller as a charging roller in an electrophotographic system, it is preferable to control the volume resistivities of the matrix and the domain within an appropriate range.

[0084] The volume resistivity R1 of the matrix is preferably greater than 1.00×10 12 Ω·cm. Thereby, it is possible to suppress the movement of charges bypassing the domains and moving in the matrix. And it is possible to suppress that most of the charges accumulated by one discharge are consumed. Also, it is possible to prevent the charges accumulated in the domains from leaking into the matrix, resulting in a state where a conductive path communicating within the conductive layer is formed. The volume resistivity R1 is preferably 2.00×10 12 Ω·cm or more.

[0085] On the other hand, the upper limit of R1 is not particularly limited, but as a guideline, it is preferably 1.00×10 17 Ω·cm or less, and more preferably 8.00×10 16 Ω·cm or less.

[0086] In order to move charges through domains in the conductive layer and achieve microdischarges, the inventors consider that a configuration in which regions (domains) where charges are sufficiently accumulated are separated by electrically insulating regions (matrix) is effective. By setting the volume resistivity of the matrix within the range of the high-resistance region as described above, sufficient charges can be retained at the interface with each domain, and charge leakage from the domain can be suppressed.

[0087] Also, in order to achieve fine discharges with a sufficient discharge amount, it is extremely effective to limit the charge movement path to a path through domains. By suppressing charge leakage from the domain to the matrix and limiting the charge transport path to a path through a plurality of domains, the density of charges present in the domain can be improved, so that the charge filling amount in each domain can be further increased.

[0088] As a result, it is considered that the total number of charges that can participate in the discharge can be improved on the surface of the domain as the conductive phase that is the starting point of the discharge, and as a result, the ease of discharge from the surface of the conductive member can be improved.

[0089] The volume resistivity of the matrix is determined by the composition of the MRC.

[0090] As the first rubber used in the MRC, a rubber with low conductivity is preferred. At least one selected from the group consisting of natural rubber, butadiene rubber, butyl rubber, acrylonitrile-butadiene rubber, urethane rubber, silicone rubber, fluororubber, isoprene rubber, chloroprene rubber, styrene-butadiene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, and polynorbornene rubber is preferred. It is more preferred that the first rubber is at least one selected from the group consisting of butyl rubber, styrene-butadiene rubber, and ethylene-propylene-diene rubber.

[0091] Also, if the volume resistivity of the matrix is within the above range, fillers, processing aids, crosslinking agents, crosslinking aids, crosslinking accelerators, crosslinking accelerator aids, crosslinking retardants, antioxidants, softeners, dispersants, colorants, etc. may be added to the MRC as necessary. On the other hand, in order to keep the volume resistivity of the matrix within the above range, it is preferable not to contain electronic conductive agents such as carbon black in the MRC.

[0092] · Method for measuring the volume resistivity of the matrix; The volume resistivity of the matrix can be measured by a microprobe after thinning the conductive layer. As a means of thinning, a means capable of producing a very thin sample such as a microtome is used. Specific procedures will be described later.

[0093] On the other hand, it is preferable that the volume resistivity R2 of the domain is smaller than the volume resistivity R1 of the matrix. Thereby, while suppressing the movement of charges not intended in the matrix, it becomes easier to limit the charge transport path to a path via a plurality of domains.

[0094] Also, the volume resistivity R1 is preferably 1.0×10 5 times or more that of R2. R1 is 1.0×10 5 times to 1.0×10 18 times that of R2, more preferably 1.0×10 6 times to 1.0×10 17 times, still more preferably 8.0×10 6 times to 1.0×10 16 times, and even more preferably 8.0×10

[0095] And R2 is preferably 1.00×10 1 Ω·cm or more and 1.00×10 4 Ω·cm or less, more preferably 1.00×10 1 Ω·cm or more and 1.00×10 2 Ω·cm or less.

[0096] By satisfying the above, the charge transport path in the conductive layer can be controlled, making it easier to achieve microdischarge. Therefore, even if a small amount of an external additive enters between the conductive member and the photosensitive drum, it becomes easier to suppress white dot-like image defects.

[0097] The volume resistivity of the domain is adjusted, for example, by changing the type and amount of the electron conductive agent with respect to the rubber component of the domain to make its conductivity a predetermined value.

[0098] As the rubber material for the domain, a rubber composition containing a rubber component for the matrix can be used. In order to form a matrix-domain structure, it is preferable to make the difference in solubility parameter (SP value) from the rubber material forming the matrix within a certain range. That is, the absolute value of the difference between the SP value of the first rubber and the SP value of the second rubber is preferably 0.4 (J / cm 3 ) 0.5 up to 5.0 (J / cm 3 ) 0.5 and more preferably 0.4 (J / cm 3 ) 0.5 or more and 2.2 (J / cm 3 ) 0.5 or less.

[0099] The volume resistivity of the domain can be adjusted by appropriately selecting the type and addition amount of the electron conductive agent. As the electron conductive agent used to control the volume resistivity of the domain to 1.00×10 1 Ωcm or more and 1.00×10 4 Ωcm or less, an electron conductive agent that can greatly change the volume resistivity from high resistance to low resistance depending on the amount of dispersion is preferable.

[0100] Examples of the electron conductive agent incorporated into the domain include oxides such as carbon black, graphite, titanium oxide, and tin oxide; metals such as Cu and Ag; and particles whose surface is coated with an oxide or metal and made conductive. Also, if necessary, two or more of these conductive agents may be blended in appropriate amounts and used.

[0101] Among the above-mentioned electron conductive agents, it is preferable to use conductive carbon black which has a large affinity with rubber and is easy to control the distance between electron conductive agents. The type of carbon black incorporated into the domain is not particularly limited. Specifically, for example, gas furnace black, oil furnace black, thermal black, lamp black, acetylene black, ketjen black, etc. can be mentioned.

[0102] Among them, conductive carbon black with a DBP oil absorption of 40 cm 3 / 100 g or more and 170 cm 3 / 100 g or less, which can impart high conductivity to the domain, can be preferably used.

[0103] The content of the electron conductive agent such as conductive carbon black is preferably 20 parts by mass or more and 150 parts by mass or less, more preferably 50 parts by mass or more and 100 parts by mass or less, based on 100 parts by mass of the second rubber contained in the domain.

[0104] Compared with a general conductive member for electrophotography, it is preferable that a large amount of the conductive agent is incorporated. Thereby, the volume resistivity of the domain can be easily controlled within the range of 1.00×10 1 Ωcm or more and 1.00×10 4 Ω·cm or less.

[0105] Also, if necessary, fillers, processing aids, crosslinking aids, crosslinking accelerators, anti-aging agents, crosslinking accelerator aids, crosslinking retarders, softeners, dispersants, colorants, etc., which are generally used as rubber compounding agents, may be added to the rubber composition for the domain within a range that does not inhibit the effects according to the present disclosure.

[0106] The volume resistivity R2 of the domain can be adjusted by the amount of the electron conductive agent in the CMB. For example, as the electron conductive agent, the DBP oil absorption is 40 cm 3 / 100 g or more and 170 cm 3Taking as an example the case of using conductive carbon black with a content of 100 g or less, the desired range can be achieved by preparing CMB so as to contain 40 to 200 parts by mass of conductive carbon black with respect to 100 parts by mass of the second rubber of CMB.

[0107] · Method for measuring volume resistivity of domain; The measurement of the volume resistivity of the domain may be carried out in the same manner as the method for measuring the volume resistivity of the matrix, except that the measurement location is changed to a location corresponding to the domain and the applied voltage during the measurement of the current value is changed to 1 V. Specific procedures will be described later.

[0108] <Shape of domain> In the conductive roller, when the length in the longitudinal direction of the conductive layer is L and the thickness of the conductive layer is T, cross-sections in the thickness direction of the conductive layer as shown in Fig. 3(b) are obtained at three locations: the center in the longitudinal direction of the conductive layer and L / 4 from both ends of the conductive layer toward the center. For each of the cross-sections in the thickness direction of the conductive layer, it is preferable to satisfy the following.

[0109] In each of the cross-sections, when observation regions of 15 μm square are placed at any three locations in the thickness region from a depth of 0.1T to 0.9T from the outer surface of the conductive layer, it is preferable that 80% or more of the domains observed in each of the total nine observation regions satisfy the following constituent elements (iv) and (v). Constituent element (iv): The ratio μr of the cross-sectional area of the electron conductive agent contained in the domain to the cross-sectional area of the domain is 20% or more. Constituent element (v): When the perimeter of the domain is A and the circumscribed perimeter of the domain is B, A / B is 1.00 or more and 1.10 or less.

[0110] The above constituent elements (iv) and (v) can be said to be regulations regarding the shape of the domain. The "shape of the domain" is defined as the cross-sectional shape of the domain appearing in the cross-section in the thickness direction of the conductive layer.

[0111] The shape of the domain is preferably a shape without irregularities on its circumferential surface, that is, a shape close to a sphere. The inventors believe that when the shape of the domain has no irregularities and is close to a sphere, the distribution of the distance between domains is averaged, and the locations where the distance between domains is non-uniform can be reduced. As a result, the interfaces between the domains and the matrix on the surface of the conductive roller are uniformly arranged, and the locations that can share the agglomerates become uniform, and the effect of transferring the agglomerates on the toner surface to the drum surface can be preferably exhibited. Furthermore, by reducing the number of concavo-convex structures related to the shape, the non-uniformity of the electric field between domains can be reduced, that is, the locations where electric field concentration occurs can be decreased, and the phenomenon of excessive charge transport in the matrix can be reduced.

[0112] The inventors have obtained the finding that the amount of the electron conductive agent contained in one domain affects the outer shape of the domain. That is, it has been found that as the filling amount of the electron conductive agent in one domain increases, the outer shape of the domain becomes closer to a sphere. The larger the number of domains close to a sphere, the fewer the concentration points of the transfer of electrons between domains. Furthermore, the shape of the domain existing on the outer surface of the conductive layer can also be made close to a circle. When the shape of the domain is close to a circle, the distance between adjacent wall surfaces of the domain becomes uniform, the uniformity of the peak pressure on the plane with respect to the agglomerates on the toner particle surface is improved, and the transfer of the agglomerates from the toner particle surface can be made more efficient. As a result, even if some contamination occurs on the surface of the conductive member, the effects of this case can be maintained.

[0113] According to the study by the inventors, based on the cross-sectional area of one domain, a domain in which the ratio μr of the total cross-sectional area of the electron conductive agent observed in the cross-section is 20% or more can take a shape closer to a sphere. Specifically, the ratio μr of the cross-sectional area of the electron conductive agent contained in the domain to the cross-sectional area of the domain is preferably 20% or more. More preferably, it is 25% or more and 30% or less.

[0114] By being within the above range, even when the contact time between the surface of the conductive member and the toner is short under a high-speed process, sufficient peak pressure can be applied to the agglomerates on the surface of the toner particles.

[0115] Regarding the shape in which the circumferential surface of the domain has no irregularities, the inventors have found that it is preferable to satisfy the following formula (5). 1.00 ≦ A / B ≦ 1.10 Formula (5) (A: Perimeter length of the domain, B: Envelope perimeter length of the domain)

[0116] Formula (5) shows the ratio of the perimeter length A of the domain to the envelope perimeter length B of the domain. Here, as shown in FIG. 6, the envelope perimeter length is the perimeter length when the convex portions of the domain 71 observed in the observation region are connected.

[0117] The ratio of the perimeter length of the domain to the envelope perimeter length of the domain has a minimum value of 1, and a state of 1 indicates that the domain has a cross-sectional shape such as a perfect circle or an ellipse without recesses. When these ratios are 1.1 or less, it indicates that there are no large irregularities in the domain, and a uniform peak pressure can be applied to the agglomerates on the surface of the toner particles. At the same time, anisotropy of the electric field in the conductive layer is less likely to occur.

[0118] <Measurement method of each parameter regarding the shape of the domain> From the conductive layer of the conductive roller, using a microtome (trade name: Leica EM FCS, manufactured by Leica Microsystems), an ultra-thin section with a thickness of 1 μm is cut out at a cutting temperature of -100°C. However, as described below, it is necessary to prepare a section by a cross-section perpendicular to the longitudinal direction of the conductive roller and evaluate the shape of the domain on the broken surface of the section. The reason for this is described below.

[0119] FIGS. 3(a) and 3(b) show diagrams showing the shape of the conductive roller 81 in three dimensions, specifically, the three axes of X, Y, and Z. In FIGS. 3(a) and 3(b), the X-axis is a direction parallel to the longitudinal direction (axial direction) of the conductive roller, and the Y-axis and Z-axis are directions perpendicular to the axial direction of the conductive roller.

[0120] FIG. 3(a) shows an image diagram of cutting out the conductive roller with a cross-section 82a parallel to the XZ plane 82 with respect to the conductive roller. The XZ plane can rotate 360° around the axis of the conductive roller. Considering that the conductive roller abuts against the photosensitive drum and rotates, and discharges when passing through the gap with the photosensitive drum, the cross-section 82a parallel to the XZ plane 82 indicates a plane where discharge occurs simultaneously at a certain timing. When a plane corresponding to a certain amount of the cross-section 82a passes through, the surface potential of the photosensitive drum is formed.

[0121] Therefore, for the evaluation of the domain shape correlated with the electric field concentration in the conductive roller, instead of analyzing the cross-section where discharge occurs simultaneously at a certain moment like the cross-section 82a, it is necessary to evaluate the cross-section parallel to the YZ plane 83 perpendicular to the axial direction of the conductive roller, which can evaluate the domain shape including a certain amount of the cross-section 82a.

[0122] For this evaluation, when the longitudinal length of the conductive layer is L, three locations are selected: the cross-section 83b at the center in the longitudinal direction of the conductive layer, and two cross-sections (83a and 83c) at L / 4 from both ends of the conductive layer towards the center.

[0123] Regarding the observation positions of the cross-sections 83a to 83c, when the thickness of the conductive layer is T, measurements may be performed in a total of nine observation regions where observation regions of 15 μm square are placed at any three locations in the thickness region from 0.1T to 0.9T in depth from the outer surface of each slice. Platinum is vapor-deposited on the obtained slice to obtain a vapor-deposited slice. Then, the surface of the vapor-deposited slice is photographed at 1000 times or 5000 times using a scanning electron microscope (SEM) (trade name: S-4800, manufactured by Hitachi High-Technologies Corporation) to obtain an observation image.

[0124] Next, in order to quantify the shape of the domain in the analyzed image, 8-bit grayscale conversion is performed using image processing software (product name: ImageProPlus; manufactured by Media Cybernetics) to obtain a monochrome image with 256 gradations. Then, the black and white of the image is inverted so that the domain in the cross-section becomes white, and a binary image is obtained.

[0125] (Method for Measuring Cross-sectional Area Ratio μr of Electron Conductive Agent in Domain) The measurement of the cross-sectional area ratio of the electron conductive agent in the domain can be performed by quantifying the binary image of the observation image taken at 5000 times magnification described above.

[0126] 8-bit grayscale conversion is performed using image processing software (product name: ImageProPlus; manufactured by Media Cybernetics) to obtain a monochrome image with 256 gradations. Binarization is performed on the observation image so that carbon black particles can be distinguished, and a binary image is obtained. By using the count function on the obtained image, the cross-sectional area S of the domain in the analyzed image and the total cross-sectional area Sc of the carbon black particles as the electron conductive agent contained in the domain are calculated.

[0127] Then, as the cross-sectional area ratio of the electron conductive agent in the domain, the arithmetic mean value μr of Sc / S at the above nine locations is calculated.

[0128] The cross-sectional area ratio μr of the electron conductive agent affects the uniformity of the volume resistivity of the domain. In combination with the measurement of the cross-sectional area ratio μr, the uniformity of the volume resistivity of the domain can be measured as follows.

[0129] By the above measurement method, as an index of the uniformity of the volume resistivity of the domain, σr / μr is calculated from μr and the standard deviation σr of μr.

[0130] (Method for Measuring Perimeter Length A and Envelope Perimeter Length B of Domain) Using the counting function of the image processing software, the following items are calculated for the domain group existing in the binary image of the observation image taken at 1000 times magnification above. · Perimeter length A (μm) · Envelope perimeter length B (μm) From these values, the ratio A / B according to the above formula (5) is obtained, and the arithmetic mean value of the nine evaluation images is adopted.

[0131] (Method for measuring the shape index of the domain) The shape index of the domain may be calculated as the percentage of the number of domains in the domain group where μr (area%) is 20% or more and the perimeter ratio A / B of the domain satisfies the above formula (5) with respect to the total number of domains. It is preferable that the shape index of the domain is 80% to 100% by number.

[0132] For the above binary image, using the counting function of the image processing software (product name: ImageProPlus; manufactured by Media Cybernetics), the number of domains in the binary image of the domain group is calculated, and further, the percentage of the number of domains satisfying μr≥20 and the above formula (5) is obtained.

[0133] As defined in component (iv), by filling the domain with a high density of an electron conductive agent, the outer shape of the domain can be made closer to a sphere, and as defined in component (v), the unevenness can be made small.

[0134] In order to obtain a domain filled with a high density of an electron conductive agent as defined in component (iv), the electron conductive agent preferably has a carbon black with a DBP oil absorption of 40 cm 3 / 100 g or more and 80 cm 3 / 100 g or less.

[0135] DBP oil absorption (cm 3"(cm³ / 100 g)" is the volume of dibutyl phthalate (DBP) that 100 g of carbon black can adsorb, and is measured in accordance with Japanese Industrial Standard (JIS) K 6217-4:2017 (Carbon black for rubber - Basic characteristics - Part 4: Method for determining oil absorption (including compressed samples)).

[0136] Generally, carbon black has a flaky higher-order structure in which primary particles with an average particle size of 10 nm or more and 50 nm or less aggregate. This flaky higher-order structure is called a structure, and the degree thereof is quantified by the DBP oil absorption amount (cm 3 / 100 g).

[0137] Conductive carbon black with a DBP oil absorption amount within the above range has a less developed structure, so there is less aggregation of carbon black and good dispersibility in rubber. Therefore, the filling amount in the domain can be increased, and as a result, it is easy to obtain a domain whose outer shape is closer to a sphere.

[0138] In addition, conductive carbon black with a DBP oil absorption amount within the above range is less likely to form aggregates, so it is easier to form a domain according to component (v).

[0139] <Domain diameter D> The arithmetic mean value of the equivalent circle diameter D of the domain (hereinafter also simply referred to as "domain diameter D") observed from the cross section of the conductive layer is preferably 0.10 μm or more and 5.00 μm or less. Within this range, since the outermost surface domain has a size equal to or smaller than that of the toner, a peak pressure can be suitably applied to the agglomerates on the toner particle surface, and at the same time, discharge finer than the toner size is possible, so a homogeneous image can be obtained and high-definition discharge can be achieved.

[0140] By setting the average value of the domain diameter D to 0.10 μm or more, an effect of applying a peak pressure to the agglomerates on the toner surface occurs, and at the same time, the path through which the charge moves in the conductive layer can be effectively limited by the target path. More preferably, it is 0.15 μm or more, and still more preferably, it is 0.20 μm or more.

[0141] Also, by setting the average value of the domain diameter D to 5.00 μm or less, domains smaller than the toner size can dramatically increase the chance of the boundary between the domain and the matrix contacting the agglomerates, and sufficient peak pressure can be applied to the agglomerates on the toner surface. Furthermore, the ratio of the surface area to the total volume of the domains, that is, the specific surface area of the domains, can be exponentially increased, and the charge release efficiency from the domains can be dramatically improved. For the reasons described above, the average value of the domain diameter D is more preferably 2.00 μm or less, and even more preferably 1.00 μm or less.

[0142] As a method for controlling the domain diameter D, for example, in component (vi), MRC and CMB are kneaded and phase-separated. And in the step of preparing a rubber mixture in which domains of CMB are formed in the matrix of MRC, a method of controlling to reduce the domain diameter of CMB can be mentioned.

[0143] By reducing the domain diameter of CMB, the specific surface area of CMB increases and the interface with the matrix increases. Therefore, a tension that attempts to reduce the tension acts on the interface of the domains of CMB. As a result, the outer shape of the domains of CMB approaches a sphere more closely.

[0144] Here, regarding the factors that determine the domain diameter in the matrix-domain structure formed when two incompatible polymers are melt-kneaded, Taylor's equation (Equation (6)), Wu's empirical equations (Equations (7), (8)), and Tokita's equation (Equation (9)) are known. · Taylor's equation D = [C·σ / ηm·γ]·f(ηm / ηd) Equation (6) · Wu's empirical equations γ·D·ηm / σ = 4(ηd / ηm)0.84·ηd / ηm > 1 Equation (7) γ·D·ηm / σ = 4(ηd / ηm)-0.84·ηd / ηm < 1 Equation (8) · Tokita's equation D = 12·P·σ·φ / (π·η·γ)·(1 + 4·P·φ·EDK / (π·η·γ)) Equation (9) In Equations (6) to (9), D represents the maximum Feret diameter of the CMB domain, C represents a constant, σ represents the interfacial tension, ηm represents the viscosity of the matrix, ηd represents the viscosity of the domain, γ represents the shear rate, η represents the viscosity of the mixed system, P represents the collision coalescence probability, φ represents the domain phase volume, and EDK represents the domain phase cutting energy.

[0145] Regarding component (iii), in order to make the distance between domains uniform, it is effective to reduce the domain diameter according to Equations (6) to (9). Furthermore, in the process of kneading the MRC and the CMB, as the raw material rubber of the domain splits and its particle size gradually becomes smaller, the distance between domains also changes depending on where the kneading process is stopped.

[0146] Therefore, the uniformity of the distance between domains can be controlled by the kneading time in the kneading process and the kneading rotation speed, which is an index of the kneading strength. The longer the kneading time and the larger the kneading rotation speed, the more the uniformity of the distance between domains can be improved.

[0147] · Uniformity of the domain diameter D; It is preferable that the domain diameter D is uniform, that is, the particle size distribution is narrow. By making the distribution of the domain diameter D through which the charges in the conductive layer pass uniform, the concentration of charges in the matrix domain structure can be suppressed, and the ease of discharging can be effectively increased over the entire surface of the conductive roller.

[0148] When obtaining a 50 μm square observation region at any three locations in the thickness region from 0.1T to 0.9T in the depth direction from the outer surface of the conductive layer towards the support in the cross-section through which the charges are transported, that is, the cross-section in the thickness direction of the conductive layer as shown in Fig. 3(b), the ratio σd / D (coefficient of variation σd / D) of the standard deviation σd of the domain diameter and the arithmetic mean value D of the domain diameter is preferably 0 or more and 0.40 or less, and more preferably 0.10 or more and 0.30 or less.

[0149] In order to improve the uniformity of the domain diameter, similar to the method for improving the uniformity of the distance between domains described above, according to formulas (6) to (9), if the domain diameter is reduced, the uniformity of the domain diameter will also be improved. Further, in the step of kneading MRC and CMB, in the process where the raw rubber of the domain splits and its particle size gradually becomes smaller, the uniformity of the domain diameter also changes depending on where the kneading step is stopped.

[0150] Therefore, the uniformity of the domain diameter can be controlled by the kneading time in the kneading step and the kneading rotation speed, which is an index of the kneading intensity. The longer the kneading time and the larger the kneading rotation speed, the more the uniformity of the domain diameter can be improved.

[0151] · Method for measuring the uniformity of the domain diameter; The measurement of the uniformity of the domain diameter can be performed by quantifying an image obtained by directly observing a fracture surface, which is obtained by the same method as the measurement of the uniformity of the distance between domains described above. Specific means will be described later.

[0152] 〔Toner〕 Hereinafter, each component constituting the toner and the manufacturing method of the toner will be described.

[0153] The toner of the present disclosure has at least toner particles, and agglomerates containing silica fine particles and a binder component are present on the surface of the toner particles. When the number ratio of the toner particles having the agglomerates is defined as CI (number %), the CI is 1% to 15% by number. When the number ratio of the toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition A is defined as Ca (number %), and the number ratio of the toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition B is defined as Cb (number %), the CI, the Ca, and the Cb satisfy formulas (1) and (2). · Ultrasonic condition A: Output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s · Ultrasonic condition B: Output frequency 30 kHz, output capacity 35 W, irradiation time 300 s 0.90 ≦ Ca / CI ≦ 1.00 Equation (1) 0.01 ≦ Cb / CI ≦ 0.10 Equation (2) It is characterized in that the arithmetic mean value Dms of the adjacent distances between domains present on the outer surface of the conductive roller and the arithmetic mean value Ag of the Feret diameter of the agglomerates satisfy the relationship Dms < Ag.

[0154] <Agglomerates and toner particles> FIG. 7 is a representative view of toner in which agglomerates are present on the surface of the toner particles.

[0155] Examples of the agglomerates containing silica fine particles and a binder component include particles mainly composed of silica and a binder component capable of binding these particles to each other.

[0156] Examples of the particles mainly composed of silica include dry silica fine particles called so-called dry method or fumed silica produced by vapor phase oxidation of silicon halide, and so-called wet silica fine particles (hereinafter also referred to as colloidal silica) produced from water glass and the like. Both can be used. These particles may be subjected to a hydrophobization treatment. Examples of the treatment agent used for the hydrophobization treatment include silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organosilicon compounds, and organotitanium compounds. These may be used alone or in combination of two or more.

[0157] The number average particle diameter of the primary particles of the silica fine particles is preferably 10 nm or more and 200 nm or less (more preferably 15 nm or more and 150 nm or less). The number average particle diameter of the primary particles of the silica fine particles is preferably measured using a photograph of the toner magnified by a scanning electron microscope.

[0158] As a binding component capable of binding particles mainly composed of silica, a component that can fix the particles with appropriate strength and does not cause adverse effects even when subjected to environmental changes such as mechanical stress, temperature, and humidity in the development process is required. Examples of such materials include organic resins. In particular, vinyl resins and polyester resins can be preferably used. These can hold particles mainly composed of silica with appropriate fixing strength, and as the toner is used, it becomes possible to continuously supply particles mainly composed of silica into the development process. Also, although the binding component itself is simultaneously supplied into the development process, by appropriately selecting the responsiveness of the binding component to environmental changes such as hardness, temperature, and humidity, it is possible to suppress member contamination and changes in development characteristics. Specific materials will be described in the section on the manufacturing method described later.

[0159] In the toner according to the present invention, when the number ratio of toner particles having the agglomerates is CI (number %), it is necessary that the CI is 1% by number or more and 15% by number or less. If the CI is too low, the number of agglomerates contained is too small, so the effects of the present disclosure cannot be obtained. If the CI is too high, the number of agglomerates contained is too large, so a large amount of agglomerates will remain on the conductive member at the nip portion of the conductive roller and the photoreceptor, deteriorating the contamination of the conductive member. The CI is preferably 2% by number or more and 14% by number or less, and more preferably 3% by number or more and 12% by number or less. Also, the CI can be controlled by adjusting manufacturing conditions such as the number of parts charged of the material, the type of material, and stirring conditions.

[0160] Furthermore, in the toner according to the present invention, when the number ratio of toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition A is Ca (number %), and the number ratio of toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition B is Cb (number %), it is necessary that the above CI, the Ca, and the Cb satisfy formulas (1) and (2). · Ultrasonic condition A: Output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s · Ultrasonic condition B: Output frequency 30 kHz, output capacity 35 W, irradiation time 300 s 0.90 ≦ Ca / CI ≦ 1.00 Formula (1) 0.01 ≦ Cb / CI ≦ 0.10 Formula (2)

[0161] That is, the range of Ca / CI needs to be 0.90 or more and 1.00 or less. When Ca / CI is less than 0.90, it means that the agglomerates are likely to migrate even under a weak shear. For this reason, the agglomerates are always easily supplied to the blocking layer, so the effect does not last long and the conductive member is also easily contaminated. The preferable range of Ca / CI is 0.95 or more and 1.00 or less. Ca / CI can be controlled by adjusting the material types of the silica fine particles and the binder component, and their respective compounding ratios, etc.

[0162] The range of Cb / CI needs to be 0.01 or more and 0.10 or less. When Cb / CI is greater than 0.10, it means that the agglomerates are difficult to migrate even at a high shear, so the effect of the present disclosure is difficult to obtain. The preferable range of Cb / CI is 0.01 or more and 0.08 or less. Cb / CI can be controlled by adjusting the material types of the silica fine particles and the binder component, and their respective compounding ratios, etc.

[0163] Furthermore, it is preferable that the arithmetic mean value Ag of the Feret diameter of the agglomerates is 1000 nm or more and 8000 nm or less. If the agglomerates are within the above range, since the agglomerates are sufficiently large, it is easy to straddle between the domain and the matrix at the nip portion of the conductive member and the photoreceptor. More preferably, it is 1300 nm or more and 7500 nm or less, and still more preferably, it is 1500 nm or more and 7000 nm or less. The arithmetic mean value Ag of the Feret diameter of the agglomerates can be controlled by adjusting the production conditions such as the particle size of the silica fine particles used, the number of charged parts, the compounding ratio of the silica fine particles and the binder component, and the stirring conditions.

[0164] Furthermore, on the surface of the toner particles having the agglomerates observed with a scanning electron microscope, it is preferable that the area ratio of the binding component of the agglomerates is 5% or more and 50% or less with respect to the entire agglomerate. As described above, by appropriately containing the binding component in the agglomerates, the migration property of the agglomerates is appropriately controlled, and the effects of the present disclosure can be obtained at a high level. If it is smaller than this range, the agglomerates are likely to migrate, easily contaminate the conductive member, and it is difficult to obtain the effects over a long life. If it is larger than this range, the agglomerates are difficult to migrate, and it is difficult to obtain the effect of improving cleaning failure. The area ratio of the binding component of the agglomerates can be controlled by adjusting the compounding ratio of the silica fine particles and the binding component, and the manufacturing conditions such as stirring conditions.

[0165] Furthermore, among the toner particles having the agglomerates, it is preferable to contain 50% by number or more of the toner particles having the agglomerates that satisfy the following (a).

[0166] (a) In an image obtained by binarizing the backscattered electron image of the agglomerate photographed by a scanning electron microscope, with the midpoint of the image of the agglomerate as a reference point, when 18 straight lines are drawn at 10° intervals so as to pass through the reference point, the number A of straight lines having a line segment with a continuous dark part length of 100 nm or more on the straight line is 12 or more with respect to the total 18 straight lines.

[0167] Satisfying the above (a) means that the binding component is evenly dispersed in the agglomerate. Therefore, variation in the migration of the agglomerates hardly occurs, and the effects of the present disclosure are easily obtained. Preferably, it is 60% by number or more, more preferably 80% by number or more.

[0168] As means for controlling the number of toner particles having the agglomerates that satisfy the above (a), it can be controlled by adjusting the manufacturing conditions such as the compounding ratio of silica and the binding component, and the dispersion conditions of the silica and the binding component used.

[0169] The toner particles contain a binder resin. The content of the binder resin is preferably 50% by mass or more with respect to the total amount of the resin components in the toner particles.

[0170] There are no particular restrictions on the adhesive resin. For example, styrene-acrylic resins, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, mixed resins and composite resins thereof can be mentioned. Styrene-acrylic resins and polyester resins are preferred in terms of low cost, easy availability and excellent low-temperature fixing properties.

[0171] Examples of the styrene-acrylic resin include polymers composed of the following monofunctional polymerizable monomers or polyfunctional polymerizable monomers, copolymers obtained by combining two or more of them, and mixtures thereof.

[0172] Examples of the monofunctional polymerizable monomer include the following.

[0173] Styrene; styrene derivatives such as α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene; acrylic polymerizable monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; methacrylic polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropyl ketone.

[0174] Examples of the polyfunctional polymerizable monomers include the following.

[0175] Diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6 - hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2'-bis(4-(acryloxy diethoxy)phenyl)propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3 - butylene glycol dimethacrylate, 1,6 - hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis(4-(methacryloxy diethoxy)phenyl)propane, 2,2'-bis(4-(methacryloxy polyethoxy)phenyl)propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, divinyl ether, etc.

[0176] As the polyester resin, those obtained by condensation polymerization of the following carboxylic acid components and alcohol components can be used. Examples of the carboxylic acid components include terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid, cyclohexanedicarboxylic acid, and trimellitic acid. Examples of the alcohol components include bisphenol A, hydrogenated bisphenol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, glycerin, trimethylolpropane, and pentaerythritol.

[0177] Also, the polyester resin may be a polyester resin containing a urea group. It is preferable not to cap the carboxy groups such as at the terminals as the polyester resin.

[0178] The toner particles may contain a colorant. As the colorant, known pigments and dyes can be used. From the viewpoint of excellent weather resistance, a pigment is preferred as the colorant.

[0179] Examples of cyan-based colorants include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds.

[0180] Specifically, the following can be mentioned. C.I. Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66.

[0181] Examples of magenta-based colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds.

[0182] Specifically, the following can be mentioned. C.I. Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254, and C.I. Pigment Violet 19.

[0183] Examples of yellow-based colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.

[0184] Specifically, the following can be mentioned. C.I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185, 191, and 194.

[0185] Examples of the black colorant include carbon black and those obtained by mixing the above yellow, magenta, and cyan colorants to obtain a black color.

[0186] These colorants can be used alone, as a mixture, or even in a solid solution state.

[0187] It is preferable to use the colorant in an amount of 1.0 to 20.0 parts by mass based on 100.0 parts by mass of the binder resin.

[0188] The toner can also contain a magnetic material to form a magnetic toner. In this case, the magnetic material can also serve as a colorant.

[0189] Examples of the magnetic material include iron oxides typified by magnetite, hematite, and ferrite; metals typified by iron, cobalt, and nickel; or alloys of these metals with other metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium, and mixtures thereof.

[0190] The toner particles may contain a release agent. As the release agent, conventionally known waxes can be used without particular limitation. Specifically, the following can be mentioned.

[0191] Petroleum waxes typified by paraffin wax, microcrystalline wax, and petrolactam, and their derivatives; montan wax and its derivatives; hydrocarbon waxes obtained by the Fischer-Tropsch method and their derivatives; polyolefin waxes typified by polyethylene and their derivatives; natural waxes typified by carnauba wax and candelilla wax, and their derivatives.

[0192] The derivatives include oxides, block copolymers with vinyl monomers, and graft-modified products.

[0193] Also, alcohols such as higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid, or their acid amides, esters, and ketones; hydrogenated castor oil and its derivatives, vegetable waxes, and animal waxes. These can be used alone or in combination.

[0194] Among these, when using polyolefins, hydrocarbon waxes by the Fischer-Tropsch method, and petroleum waxes, the developability and transferability tend to improve, which is preferable.

[0195] In addition, antioxidants may be added to these waxes as long as the above effects are not affected.

[0196] The content of the release agent is preferably 1.0 part by mass or more and 30.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin or the polymerizable monomer forming the binder resin.

[0197] The melting point of the release agent is preferably 30°C or higher and 120°C or lower, more preferably 60°C or higher and 100°C or lower.

[0198] By using a release agent having the above thermal properties, the release effect is efficiently exhibited, and a wider fixing area is ensured.

[0199] Within the range not impairing the effects of the present case, various organic or inorganic fine powders may be added as external additives to the toner particles as necessary. The organic or inorganic fine powders preferably have a particle size of 1 / 10 or less of the weight average particle size of the toner particles due to the durability when added to the toner particles.

[0200] Examples of the organic or inorganic fine powders used include the following. (1) Fluidity imparting agents: silica, alumina, titanium oxide, carbon black, and carbon fluoride. (2) Abrasive: Metal oxides (e.g., strontium titanate, cerium oxide, alumina, magnesium oxide, chromium oxide), nitrides (e.g., silicon nitride), carbides (e.g., silicon carbide), metal salts (e.g., calcium sulfate, barium sulfate, calcium carbonate). (3) Lubricant: Fluorine-based resin powder (e.g., vinylidene fluoride, polytetrafluoroethylene), fatty acid metal salts (e.g., zinc stearate, calcium stearate). (4) Charge control particles: Metal oxides (e.g., tin oxide, titanium oxide, zinc oxide, silica, alumina), carbon black, hydrotalcite.

[0201] The organic or inorganic fine powder may have its surface hydrophobized for improving the fluidity of the toner and making the charging of toner particles uniform. Examples of the treating agent for hydrophobizing the organic or inorganic fine powder include unmodified silicone varnish, various modified silicone varnishes, unmodified silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organosilicon compounds, and organic titanium compounds. These treating agents may be used alone or in combination.

[0202] Among them, it is preferable to contain hydrotalcite, which is a layered composite compound, as an external additive. By containing hydrotalcite having an opposite-polarity charge property with respect to silica, which is the main component constituting the agglomerates, the charging property of the toner, specifically, the charging rise property under a high-temperature and high-humidity environment where the charging rise property is strict, is improved. Furthermore, it is more preferable that the hydrotalcite is fluorine-treated. It is considered that a higher effect can be obtained because the inclusion of fluorine with a high electronegativity in the hydrotalcite promotes the transfer of charges more.

[0203] 〔Method for manufacturing toner〕 Hereinafter, an example of the method for obtaining the above toner particles will be described, but it is not limited to the following.

[0204] The method for manufacturing toner particles is not particularly limited, and suspension polymerization, dissolution suspension, emulsion aggregation, pulverization, etc. can be used. As an example, a method for obtaining toner particles by emulsion aggregation will be described below.

[0205] <Method for manufacturing toner particles (toner core particles) by emulsion aggregation method> (Preparation step of resin fine particle dispersion) The resin fine particle dispersion can be prepared by known methods, but is not limited to these methods. For example, emulsion polymerization method, self-emulsification method, phase inversion emulsification method in which an aqueous medium is added to a resin solution dissolved in an organic solvent to emulsify the resin, or forced emulsification method in which the resin is forcibly emulsified by heat treatment in an aqueous medium without using an organic solvent can be mentioned.

[0206] As an example, a method for preparing a resin fine particle dispersion by phase inversion emulsification method will be described below.

[0207] Dissolve the resin component in an organic solvent in which these are soluble, and add a surfactant or a basic compound. At that time, if the resin component is a crystalline resin having a melting point, it may be heated to a temperature above the melting point and dissolved. Subsequently, while stirring with a homogenizer or the like, an aqueous medium is slowly added to precipitate resin fine particles. Then, the solvent is removed by heating or reducing the pressure to prepare an aqueous dispersion of resin fine particles.

[0208] Here, the organic solvent used for dissolving the resin component may be any one that can dissolve these. Specifically, toluene, xylene, etc. can be mentioned.

[0209] Examples of the surfactant used during the preparation step include anionic surfactants such as sulfate ester salts, sulfonate salts, carboxylate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols.

[0210] Examples of basic compounds used in the preparation process include inorganic bases such as sodium hydroxide and potassium hydroxide; and organic bases such as ammonia, triethylamine, trimethylamine, dimethylaminoethanol, and diethylaminoethanol. The basic compound may be used alone or in combination of two or more.

[0211] (Preparation of Colorant Dispersion) For the preparation of the colorant dispersion, known dispersion methods can be used. For example, general dispersion means such as a homogenizer, a ball mill, a colloid mill, and an ultrasonic disperser can be used without any limitation. Examples of surfactants used during dispersion include the surfactants described above.

[0212] (Preparation of Wax Dispersion) In the preparation of the wax dispersion, the wax is dispersed in water together with a surfactant, a basic compound, etc., and then heated to a temperature equal to or higher than the melting point of the wax, and dispersion treatment is performed using a homogenizer or a disperser that applies a strong shearing force. By undergoing such treatment, a wax dispersion can be obtained. Examples of surfactants used during dispersion include the surfactants described above. Examples of basic compounds used during dispersion include the basic compounds described above.

[0213] (Agglomerated Particle Formation Step) In the agglomerated particle formation step, first, a resin fine particle dispersion, a colorant dispersion, a wax dispersion, etc. are mixed to obtain a mixed solution. Then, while heating at a temperature equal to or lower than the melting point of the resin fine particles, the pH is made acidic to cause agglomeration, and agglomerated particles containing resin fine particles, colorant particles, and release agent particles are formed to obtain an agglomerated particle dispersion.

[0214] (First Fusion Step) In the first fusion step, under stirring conditions similar to those in the agglomerated particle formation step, the pH of the agglomerated particle dispersion is increased to stop the progress of agglomeration, and heating is performed at a temperature equal to or higher than the melting point of the resin component to obtain a fused particle dispersion.

[0215] (Amorphous resin fine particle adhesion step) In the amorphous resin fine particle adhesion step, an amorphous resin particle dispersion liquid is added to the fused particle dispersion liquid, and the pH is lowered to cause the amorphous resin particles to adhere to the surface of the fused particles, thereby obtaining a dispersion liquid of resin-adhered particles. Here, this coating layer corresponds to the shell layer formed through the shell layer formation step described later. Note that the amorphous resin fine particle dispersion liquid can be manufactured according to the preparation step of the resin fine particle dispersion liquid described above.

[0216] (Second fusion step) In the second fusion step, in accordance with the first fusion step, the progress of aggregation is stopped by raising the pH of the resin-adhered particle dispersion liquid, and the adhered resin aggregated particles are fused by heating at a temperature equal to or higher than the melting point of the resin component to obtain a toner core particle dispersion liquid in which toner core particles with a shell layer formed are dispersed.

[0217] (Method for manufacturing toner particles having agglomerates) As a method for manufacturing toner particles having agglomerates containing silica fine particles and a binder component, from the viewpoint of uniformly aggregating the silica fine particles and the binder component, it is preferable to externally add them to the toner core particles in a wet manner. When obtaining toner particles having agglomerates containing silica fine particles and a binder component in a wet manner, (Step 1) A step of obtaining a toner core particle dispersion liquid in which toner core particles are dispersed in an aqueous medium, and (Step 2) A step of mixing silica fine particles and a polymerizable monomer (monomer) serving as a binder resin component into the toner core particle dispersion liquid, and polymerizing the monomer in the toner core particle dispersion liquid to form agglomerates having silica fine particles and a binder resin on the toner core particles are preferably included.

[0218] In Step 1, as a method for obtaining the toner core particle dispersion liquid, there are a method of directly using the dispersion liquid of the toner core particles manufactured in an aqueous medium, and a method of charging the dried toner core particles into an aqueous medium and mechanically dispersing them. When dispersing the dried toner core particles in an aqueous medium, a dispersion aid may be used.

[0219] As the dispersion aid, known dispersion stabilizers, surfactants, etc. can be used. Specifically, the following can be mentioned as dispersion stabilizers.

[0220] Inorganic dispersion stabilizers such as tricalcium phosphate, hydroxyapatite, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina; organic dispersion stabilizers such as polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch.

[0221] Also, the following can be mentioned as surfactants. Anionic surfactants such as alkyl sulfate esters, alkylbenzene sulfonates, fatty acid salts; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxypropylene alkyl ethers; cationic surfactants such as alkylamine salts, quaternary ammonium salts.

[0222] In Step 1, it is preferable to adjust the solid content concentration of the toner core particle dispersion to 10% by mass or more and 50% by mass or less.

[0223] In Step 2, the silica fine particles and the monomer serving as the binder component may be added directly to the toner core particle dispersion, or a dispersion obtained by previously dispersing the silica fine particles and the monomer may be added to the toner core particle dispersion. As the means for dispersing the silica fine particles and the monomer, the dispersion aids exemplified in the section of Step 1 can be used.

[0224] Examples of the binder component include polymers composed of monofunctional polymerizable monomers or polyfunctional polymerizable monomers, copolymers obtained by combining two or more of these, and mixtures thereof.

[0225] Examples of the above-mentioned polymerizable monomers include the following.

[0226] Styrene; styrene derivatives such as α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene; acrylic polymerizable monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; methacrylic polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropyl ketone; trifunctional silane compounds having a methacryloxyalkyl group as a substituent such as γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxyoctyltrimethoxysilane, γ-methacryloxypropyldiethoxymethoxysilane, γ-methacryloxypropylethoxydimethoxysilane; Trifunctional silane compounds having an acryloxyalkyl group as a substituent, such as γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxyoctyltrimethoxysilane, γ-acryloxypropyldiethoxymethoxysilane, γ-acryloxypropylethoxydimethoxysilane, etc.

[0227] Among them, from the viewpoint of high affinity with silica, it is preferable to use a trifunctional silane compound. Also, the following may be used in combination with the trifunctional silane compound. An organosilicon compound having 4 reactive groups in one molecule (tetrafunctional silane), an organosilicon compound having 2 reactive groups in one molecule (bifunctional silane), or an organosilicon compound having 1 reactive group in one molecule (monofunctional silane). For example, the following can be mentioned.

[0228] Trifunctional vinylsilanes such as dimethyldiethoxysilane, tetraethoxysilane, hexamethyldisilazane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, vinyltriisocyanatosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyldiethoxymethoxysilane, vinylethoxydimethoxysilane, vinylethoxydihydroxysilane, vinyldimethoxyhydroxysilane, vinylethoxymethoxyhydroxysilane, vinyldiethoxyhydroxysilane.

[0229] In step 2, silica fine particles and a monomer as a binder component are added to and mixed with the toner core particle dispersion. At this time, it is preferable to adjust the temperature of the toner core particle dispersion to a temperature suitable for the polymerization reaction. Then, while mixing the toner core particles, silica fine particles, and the monomer, a polymerization initiator is added to polymerize the added monomer, and aggregates containing silica fine particles and a binder component are externally added to the toner core particles to obtain a dispersion of toner particles.

[0230] As the polymerization initiator, a known polymerization initiator can be used without particular limitation. Specifically, the following can be mentioned.

[0231] Hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxydicarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, tert-hydroperoxide of pertrityl acetate, tert-butyl peroxyformate, tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl permethoxyacetate, tert-butyl N-(3-toluoyl)palmitate benzoyl peroxide, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide and other peroxide-based polymerization initiators; 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and other azo-based or diazo-based polymerization initiators; etc.

[0232] (Filtration process, washing process, drying process, classification process, external addition process) Thereafter, a filtration process for filtering out the solid content of the toner particles, a washing process as necessary, a drying process, and a classification process for adjusting the particle size are performed to obtain toner particles. The toner particles may be used as toner as they are. If necessary, the toner particles and an external additive such as inorganic fine powder are mixed and adhered using a mixer to obtain toner.

[0233] 〔Process Cartridge〕 The process cartridge of the present invention includes a charging means (charging device) for charging the surface of an electrophotographic photoreceptor, a cleaning means for removing residual toner in a region upstream of the charging device, and a developing means (developing device) for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor with toner to form a toner image on the surface of the electrophotographic photoreceptor, and the developing device has toner in a toner storage portion (toner container), the charging device has a conductive roller disposed so as to be contactable with the electrophotographic photoreceptor. Then, the above-described toner and conductive roller can be applied to this process cartridge. Note that the process cartridge may have a frame for supporting the charging device and the developing device.

[0234] FIG. 4 is a schematic cross-sectional view of an electrophotographic process cartridge including a conductive roller as a charging roller. This process cartridge integrates a developing device and a charging device and is configured to be detachable from the main body of an electrophotographic device described later.

[0235] The developing device includes at least a developing roller 93 and has toner 99 in a toner container 96. The developing device may integrally include a toner supply roller 94, a developing blade 98, and a stirring blade 910 as necessary.

[0236] The charging device only needs to include at least a charging roller 92, and includes a cleaning blade 95 and a waste toner container 97 as cleaning means. Since the conductive roller only needs to be disposed so as to be contactable with the electrophotographic photoreceptor, the electrophotographic photoreceptor (photosensitive drum 91) may be integrated with the charging device as a component of the process cartridge, or may be fixed to the main body as a component of the electrophotographic device.

[0237] Voltages are applied to the charging roller 92, the developing roller 93, the toner supply roller 94, and the developing blade 98, respectively.

[0238] [Electrophotographic apparatus] An electrophotographic apparatus includes an electrophotographic photoreceptor, a charging device for charging the surface of the electrophotographic photoreceptor, cleaning means for removing residual toner in a region upstream of the charging device, and a developing device for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor with toner to form a toner image on the surface of the electrophotographic photoreceptor. The charging device has a conductive roller disposed so as to be contactable with the electrophotographic photoreceptor. The above-described toner and conductive roller can be applied to this electrophotographic apparatus.

[0239] The electrophotographic apparatus may further include an image exposure device for irradiating image exposure light onto the surface of the electrophotographic photoreceptor to form an electrostatic latent image on the surface of the electrophotographic photoreceptor, a transfer device for transferring the toner image formed on the surface of the electrophotographic photoreceptor onto a recording medium, and a fixing device for fixing the toner image transferred onto the recording medium onto the recording medium.

[0240] FIG. 5 is a schematic configuration diagram of an electrophotographic apparatus using a conductive roller as a charging roller. This electrophotographic apparatus is a color electrophotographic apparatus to which four process cartridges are detachably attached. Toners of respective colors of black, magenta, yellow, and cyan are used in each process cartridge.

[0241] The photosensitive drum 101 rotates in the direction of the arrow and is uniformly charged by the charging roller 102 to which a voltage is applied from a charging bias power source. An electrostatic latent image is formed on its surface by the exposure light 1011. On the other hand, the toner 109 stored in the toner container 106 is supplied to the toner supply roller 104 by the stirring blade 1010 and conveyed onto the developing roller 103.

[0242] Then, the developing blade 108 that is in contact with the developing roller 103 uniformly coats the toner 109 on the surface of the developing roller 103, and charges are applied to the toner 109 by triboelectrification. The electrostatic latent image is developed by being applied with the toner 109 conveyed by the developing roller 103 that is in contact with the photosensitive drum 101, and is visualized as a toner image.

[0243] The visualized toner image on the photosensitive drum is transferred to the intermediate transfer belt 1015 supported and driven by the tension roller 1013 and the intermediate transfer belt driving roller 1014 by the primary transfer roller 1012 to which a voltage is applied by the primary transfer bias power source. The toner images of each color are sequentially superimposed to form a color image on the intermediate transfer belt.

[0244] The transfer material 1019 is fed into the apparatus by a paper feed roller and conveyed between the intermediate transfer belt 1015 and the secondary transfer roller 1016. The secondary transfer roller 1016 has a voltage applied from the secondary transfer bias power source and transfers the color image on the intermediate transfer belt 1015 to the transfer material 1019. The transfer material 1019 onto which the color image has been transferred is subjected to a fixing process by the fixing device 1018, is discharged as waste paper outside the apparatus, and the printing operation ends.

[0245] On the other hand, the toner remaining on the photosensitive drum without being transferred is scraped off by the cleaning blade 105 and stored in the waste toner storage container 107, and the cleaned photosensitive drum 101 repeats the above-described steps. Also, the toner remaining on the primary transfer belt without being transferred is scraped off by the cleaning device 1017.

[0246] 〔Process Cartridge Set〕 The process cartridge set of the present invention is a process cartridge set having a first cartridge and a second cartridge that are detachable from the main body of an electrophotographic apparatus, The first cartridge has a charging device for charging the surface of the electrophotographic photoreceptor, a cleaning means for removing residual toner in the region upstream of the charging device, and a first frame for supporting the charging device and the cleaning means. The second cartridge has a toner container that contains toner for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor to form a toner image on the surface of the electrophotographic photoreceptor. The charging device has a conductive roller disposed in contact with the electrophotographic photoreceptor.

[0247] The toner and the conductive roller described above can be applied to this cartridge set.

[0248] Since the conductive roller may be disposed in contact with the electrophotographic photoreceptor, the first cartridge may include the electrophotographic photoreceptor, or the electrophotographic photoreceptor may be fixed to the main body of the electrophotographic apparatus. For example, the first cartridge may have an electrophotographic photoreceptor, a charging device for charging the surface of the electrophotographic photoreceptor, and a first frame for supporting the electrophotographic photoreceptor and the charging device. Note that the second cartridge may also include the electrophotographic photoreceptor.

[0249] The first cartridge or the second cartridge may include a developing device for forming a toner image on the surface of the electrophotographic photoreceptor. The developing device may be fixed to the main body of the electrophotographic apparatus.

[0250] [Method for Measuring Toner Physical Properties] The method for measuring various physical properties of the toner according to the present invention will be described below.

[0251] [Method for Measuring Weight Average Particle Diameter (D4) and Number Average Particle Diameter (D1)] The weight average particle diameter (D4) and number average particle diameter (D1) of the toner are calculated as follows. As the measuring device, a precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For the setting of the measurement conditions and the analysis of the measurement data, the attached dedicated software "Beckman Coulter Multisizer 3 Version3.51" (manufactured by Beckman Coulter, Inc.) is used. Incidentally, the measurement is performed with an effective number of measurement channels of 25,000 channels.

[0252] The electrolytic aqueous solution used for the measurement is a solution obtained by dissolving special grade sodium chloride in ion-exchanged water so that the concentration becomes about 1% by mass. For example, "ISOTON II" (manufactured by Beckman Coulter, Inc.) can be used.

[0253] Incidentally, before performing the measurement and analysis, the settings of the dedicated software were made as follows.

[0254] On the "Change Standard Measurement Method (SOMME)" screen of the dedicated software, set the total count number in the control mode to 50,000 particles, the number of measurements to 1 time, and the Kd value to the value obtained using "Standard Particle 10.0 μm" (manufactured by Beckman Coulter, Inc.). By pressing the "Measurement Button for Threshold / Noise Level", the threshold and noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check "Flash of Aperture Tube after Measurement".

[0255] On the "Conversion Setting from Pulse to Particle Size" screen of the dedicated software, set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 2 μm to 60 μm. The specific measurement method is as follows. (1) Pour approximately 200 ml of the electrolytic aqueous solution into a 250 ml round-bottom glass beaker dedicated to the Multisizer 3, set it on the sample stand, and stir with a stirrer rod counterclockwise at 24 revolutions per second. Then, use the "aperture flash" function of the dedicated software to remove dirt and bubbles in the aperture tube. (2) Pour approximately 30 ml of the electrolytic aqueous solution into a 100 ml flat-bottom glass beaker. Add approximately 0.3 ml of a dilution obtained by diluting "Contaminon N" (a 10% by mass aqueous solution of a neutral detergent for precision measuring instrument cleaning with pH 7, composed of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) as a dispersant about 3 times by mass with ion-exchanged water. (3) Prepare an ultrasonic disperser "Ultrasonic Dispension System Tetra150" (manufactured by Nikkaki Bios Co., Ltd.) with two oscillators operating at an oscillation frequency of 50 kHz and a phase shift of 180 degrees, and an electrical output of 120 W. Pour approximately 3.3 l of ion-exchanged water into the water tank of the ultrasonic disperser, and add approximately 2 ml of Contaminon N to this water tank. (4) Set the beaker in (2) in the beaker fixing hole of the ultrasonic disperser and operate the ultrasonic disperser. Then, adjust the height position of the beaker so that the resonance state of the liquid level of the electrolytic aqueous solution in the beaker is maximized. (5) While irradiating the electrolytic aqueous solution in the beaker in (4) with ultrasonic waves, add approximately 10 mg of toner little by little to the electrolytic aqueous solution and disperse it. Then, continue the ultrasonic dispersion treatment for another 60 seconds. Note that during ultrasonic dispersion, appropriately adjust the water temperature in the water tank to be between 10°C and 40°C. (6) Using a pipette, drop the electrolytic aqueous solution in (5) in which the toner is dispersed into the round-bottom beaker in (1) placed in the sample stand, and adjust it so that the measured concentration is approximately 5%. Then, perform the measurement until the measured number of particles reaches 50,000. (7) Analyze the measurement data using the dedicated software attached to the apparatus to calculate the weight average particle diameter (D4) and the number average particle diameter (D1). When set to graph / volume% in the dedicated software, the "average diameter" on the "Analysis / Volume Statistical Value (Arithmetic Mean)" screen is the weight average particle diameter (D4), and when set to graph / number% in the dedicated software, the "average diameter" on the "Analysis / Number Statistical Value (Arithmetic Mean)" screen is the number average particle diameter (D1).

[0256] <Method for Obtaining Reflection Electron Image of Toner Surface> The matrix exposure rate of the toner is calculated using the reflection electron image of the toner particle surface.

[0257] The reflection electron image of the toner surface was obtained by a scanning electron microscope (SEM).

[0258] The reflection electron image obtained from the SEM is also called a "composite image", and substances with a smaller atomic number are detected darker, while those with a larger atomic number are detected brighter.

[0259] Toner particles are generally resin particles mainly containing a composition mainly composed of carbon such as a resin component and a release agent. When silica fine particles or metal oxides are present on the toner particle surface, in the reflection electron image obtained from the SEM, the silica fine particles or metal oxides are observed as bright parts, and the resin part mainly composed of carbon is observed as a dark part.

[0260] The apparatus and observation conditions of the SEM are as follows. Apparatus used: ULTRA PLUS manufactured by Carl Zeiss Microscopy GmbH Acceleration voltage: 1.0 kV WD: 2.0 mm Aperture Size: 30.0 μm Detection signal: EsB (energy-selective backscattered electron) EsB Grid: 800 V Observation magnification: 50,000 times Contrast: 63.0 ± 5.0% (reference value) Brightness: 38.0 ± 5.0% (reference value) Resolution: 1024×768 Pretreatment: Sprinkle toner particles on carbon tape (no vapor deposition) The contrast and brightness should be appropriately set according to the state of the device in use. Also, the acceleration voltage and EsB Grid are set to achieve items such as obtaining the structural information of the outermost surface of the toner particles, preventing charge-up of the non-vapor-deposited sample, and selectively detecting high-energy reflected electrons. The observation field of view is selected near the apex where the curvature of the toner particles is the smallest.

[0261] <Method for confirming that the dark part in the reflected electron image is derived from carbon atoms> To confirm that the dark part in the observed reflected electron image is derived from resin, it is confirmed by superimposing the elemental mapping image obtained by energy-dispersive X-ray analysis (EDS) with a scanning electron microscope (SEM) and the said reflected electron image.

[0262] The equipment and observation conditions of SEM / EDS are as follows. Equipment used (SEM): ULTRA PLUS manufactured by Carl Zeiss Microscopy GmbH Equipment used (EDS): NORAN manufactured by Thermo Fisher Scientific Inc. System 7, Ultra Dry EDS Detecter Acceleration voltage: 5.0 kV WD: 7.0 mm Aperture Size: 30.0 μm Detection signal: SE2 (secondary electron) Observation magnification: 50,000 times Mode: Spectral Imaging Pretreatment: Sprinkle toner particles on carbon tape and platinum sputtering Superimpose the elemental mapping image obtained by this method and the said reflected electron image, and confirm that the carbon atom part of the mapping image coincides with the dark part of the reflected electron image.

[0263] <Method for confirming the dispersion state of the binder component contained in the agglomerate> The dispersion state of the binder component contained in the agglomerate is calculated using the reflected electron image of the agglomerate on the toner surface. The reflected electron image of the agglomerate on the toner surface is obtained in the same manner as the method for obtaining the reflected electron image of the toner surface.

[0264] For the obtained reflected electron image, the dispersion state of the binder component contained in the agglomerate is calculated using the image processing software ImageJ (developed by Wayne Rashand). The procedure is shown below.

[0265] First, convert the reflected electron image to be analyzed from the Type in the Image menu to 8-bit. Next, from the Filters in the Process menu, set the Median diameter to 2.0 pixels to reduce image noise. Estimate the center of the image excluding the observation condition display part shown at the bottom of the reflected electron image, and select a range of 1.5 μm square from the center of the reflected electron image using the rectangle tool in the toolbar.

[0266] Next, select Threshold from Adjust in the Image menu. In the manual operation, select all the pixels corresponding to the luminance B1 and click Apply to obtain a binary image. By this operation, the pixels corresponding to A1 are displayed in black (pixel group A1), and the pixels corresponding to A2 are displayed in white (pixel group A2). Again, estimate the center of the image excluding the observation condition display part shown at the bottom of the reflected electron image, and select a range of 1.5 μm square from the center of the reflected electron image using the rectangle tool in the toolbar.

[0267] Next, using the straight line tool in the toolbar, select the scale bar in the observation condition display part shown at the bottom of the reflected electron image. When Set Scale in the Analyze menu is selected in that state, a new window opens and the pixel distance of the selected straight line is input in the Distance in Pixels column.

[0268] Enter the value of the scale bar (e.g., 100) in the Known Distance column of the window, enter the unit of the scale bar (e.g., nm) in the Unit of Mesurement column, and click OK to complete the scale setting.

[0269] Subsequently, select Set Mesurements in the Analyze menu and check Area and Feret’s diameter. Select Analyze Particles in the Analyze menu, check Display Result and click OK to perform domain analysis.

[0270] Subsequently, perform an Erode process for 10 pixels on the obtained analysis image using ImageJ, and then perform a Dilate process for 10 pixels using ImageJ. Note that the Erode process and the Dilate process are performed from the Binary item in the Process menu. FIG. 8 illustrates an image obtained by performing the above processes.

[0271] For the analysis image obtained after the above process, using the straight line tool (Straight Line) in the toolbar, with the midpoint of the analysis image as the reference point, draw a total of 18 straight lines at 10° intervals from one end of the image to the other end so as to pass through the reference point. FIG. 9 illustrates an image with line segments drawn.

[0272] Subsequently, measure the length L of the line segment where the bright part is continuous on the straight line, count the number of straight lines having a line segment with a length L of 100 nm or more, and check whether the number of straight lines in the agglomerate is 12 or more.

[0273] <Method for checking the ratio of toner particles containing agglomerates with 12 or more straight lines> For 30 toner particles having agglomerates contained in the toner to be evaluated, perform the above procedure on the agglomerates, count the number of toner particles having agglomerates with 12 or more straight lines, and calculate the ratio A of toner particles containing agglomerates with 12 or more straight lines from the following formula. A = (the number of toner particles containing agglomerates where the number of the straight lines is 12 or more) / 30

[0274] <Method for confirming the area ratio of the binder component contained in the agglomerate> The area ratio of the binder component is calculated based on the domain D1 of the binder component and the domain D2 that is not the binder component, using the backscattered electron image of the agglomerate on the toner surface. The backscattered electron image of the agglomerate on the toner surface is obtained in the same manner as the method for obtaining the backscattered electron image of the toner surface.

[0275] The analysis of domains D1 and D2 is performed using the image processing software ImageJ (developed by Wayne Rashand) on the outermost surface backscattered electron image of the toner particles obtained by the above method. The procedure is shown below.

[0276] First, convert the backscattered electron image to be analyzed to 8-bit from the Type in the Image menu. Next, set the Median diameter to 2.0 pixels from the Filters in the Process menu to reduce image noise. Estimate the center of the image excluding the observation condition display part shown at the bottom of the backscattered electron image, and select a range of 1.5 μm square from the center of the backscattered electron image using the rectangle tool in the toolbar.

[0277] Next, use the Freehand selections function in the Image menu to select only the part where the carbon atom part of the mapping image coincides with the dark part of the backscattered electron image and fill it all in black. Also, fill in white all parts other than the part where the carbon atom part of the mapping image coincides with the dark part of the backscattered electron image. Next, select Threshold from Adjust. In manual operation, select 128, which is the middle tone between black and white in an 8-bit image, as the threshold value, and click Apply to obtain a binary image.

[0278] By this operation, the pixels corresponding to domain D1 (binder component) are displayed in black (pixel group A1), and the pixels corresponding to domain D2 (other than the binder component) are displayed in white (pixel group A2).

[0279] Again, estimate the image center excluding the observation condition display section shown at the bottom of the secondary electron image, and select a range of 1.5 μm square from the image center of the secondary electron image using the rectangle tool in the toolbar.

[0280] Next, select the scale bar in the observation condition display section shown at the bottom of the secondary electron image using the straight line tool in the toolbar. When Set Scale in the Analyze menu is selected in this state, a new window opens and the pixel distance of the selected straight line is input in the Distance in Pixels column.

[0281] Input the value of the scale bar (for example, 100) in the Known Distance column of the window, input the unit of the scale bar (for example, nm) in the Unit of Measurement column, and click OK to complete the scale setting.

[0282] Subsequently, select Set Measurements in the Analyze menu, and check Area and Feret’s diameter. Select Analyze Particles in the Analyze menu, check Display Result, and click OK to perform domain analysis.

[0283] From the newly opened Results window, obtain the area of each domain corresponding to domain D1 formed by pixel group A1 and domain D2 formed by pixel group A2.

[0284] Let the sum of the areas of domain D1 derived from the binder component be S1 (μm 2 ) and the sum of the areas of domain D2 derived from other than the binder component be S2 (μm 2 ). Calculate the area ratio S of the binder component from the obtained S1 and S2 using the following formula. S (area %) = {S1 / (S1 + S2)} × 100

[0285] Perform the above procedure for 10 fields of view for the toner particles to be evaluated, and use the arithmetic mean value as the area ratio.

[0286] <Observation method of toner and calculation method of number of toner particles> The toner is observed using a scanning electron microscope (SEM).

[0287] The SEM apparatus and observation conditions are as follows. Apparatus used: ULTRA PLUS manufactured by Carl Zeiss Microscopy GmbH Acceleration voltage: 1.0 kV WD: 2.0 mm Aperture Size: 30.0 μm Detection signal: SE2 (secondary electron) Observation magnification: 2,000 times Contrast: 45.0 ± 5.0% (reference value) Brightness: 38.0 ± 5.0% (reference value) Resolution: 1024 × 768 Pretreatment: Sprinkle toner particles on carbon tape (no evaporation) The contrast and brightness are appropriately set according to the state of the apparatus used. Also, the acceleration voltage is set so as to achieve items such as acquisition of the outermost surface structure information of toner particles and prevention of charge-up of non-evaporated samples.

[0288] The number of observation fields of view is observed until the number of fields of view in which the entire particles are within the observation field of view in the obtained secondary electron image and the number of toner particles is counted and the number is defined as Tall (pieces) and Tall is 300 pieces or more.

[0289] <Calculation method of number CI of toner particles having agglomerates> In all of the secondary electron images of the number of visual fields obtained from the above observations, count the number of toner particles containing agglomerates among the toner particles in which the entire particle is within the observation visual field, and denote it as Tagg (pieces). For the toner containing agglomerates, count the number of toner particles as shown in Fig. 7.

[0290] From the obtained Tall (pieces) and Tagg (pieces), calculate CI (number %) using the following formula. CI (number %) = Tagg / Tall × 100

[0291] <Method for Measuring the Size of Agglomerates and Method for Counting Toner Having Agglomerates> In the above-described scanning electron microscope observation, photograph and save the entire toner at an appropriate magnification (5k - 10k). The image resolution shall be 1024 × 768 pixels. From the obtained SEM image, select the portion determined to be an agglomerate on the image using the image analysis software Image J (developed by Wayne Rasband). The size of the agglomerate is defined by the maximum Feret diameter of this selected region. The calculation procedure is shown below. a) Set the scale by [Analyze] - [Set Scale]. b) Check [Analyze] - [Set Measurements] - [Feret’s diameter]. c) Select [Freehand Selections] and manually select the agglomerates on the image. d) Select [Analyze] - [Measure] to obtain the maximum Feret diameter (Feret) of the selected portion. e) If there are multiple agglomerates on the image, repeat steps c) and d). f) Perform the same analysis on the remaining 9 images of the toner observed to have agglomerates with a maximum Feret diameter of 500 nm or more and 8000 nm or less. g) Take the maximum value of Feret (Feret diameter) of the obtained analysis results as the maximum Feret diameter. Those with a maximum Feret diameter of 500 nm or more and 8000 nm or less are regarded as agglomerates.

[0292] Arbitrarily observe the toner with a scanning electron microscope, and let Ag be the arithmetic mean value of the maximum Feret diameter of a total of 100 agglomerates.

[0293] Also, among the arbitrarily observed toner particles, let CI be the percentage of toner particles having agglomerates.

[0294] <Evaluation method for the presence of silica and binder components in agglomerates> Regarding the confirmation of the presence of silica and binder components in the agglomerates, it is carried out using STEM-EDX and a scanning electron microscope.

[0295] First, for the toner having agglomerates, evaluate the cross-sectional structure and composition of the agglomerates using STEM-EDX.

[0296] Using an osmium plasma coater (Filgen, OPC80T), apply an Os film (5 nm) and a naphthalene film (20 nm) to the toner as a protective film, embed it with a photocurable resin D800 (JEOL), and then use an ultrasonic ultramicrotome (Leica, UC7) to produce a cross-section of the toner particle with a film thickness of 100 nm at a cutting speed of 1 mm / s. At this time, a plurality of toners may be processed collectively to obtain 300 to 500 toner cross-sections. A schematic diagram of the cross-section of the toner having agglomerates is shown in FIG. 10.

[0297] For the obtained cross-section, perform STEM-EDX observation using the STEM function of TEM-EDX (TEM: JEOL, JEM2800 (200 keV), EDX detector: JEOL, dry SD 100GV, EDX system: Thermo Fisher, NORAN SYSTEM7). The probe size of STEM is 1.0 nm, the observation magnification is 50 to 300k, the image size of EDX is 256×256 pixels, and it is acquired by adjusting the storage rate to 10,000 cps and integrating 50 frames. The observation location is set so that the field of view includes the agglomerates present in the outer peripheral part of the toner particle.

[0298] The presence of particles mainly composed of silica and a binding component in the agglomerates can be determined by confirming that a portion with a large amount of silicon and oxygen and a portion with a large amount of elements derived from the binding component exist separately at the same location. When a resin is used as the binding component, a large amount of carbon is observed.

[0299] Next, for the toner having agglomerates, observation of a backscattered electron image is performed using a scanning electron microscope. The image acquisition conditions are as follows.

[0300] (1) Sample preparation Stick carbon tape on the sample stage (aluminum sample stage 12.5 mm φ × 6 mm t), and place the toner on it. Further, blow air to remove excess sample from the sample stage. Set the sample stage in the sample holder and set it in a scanning electron microscope (Zeiss UltraPlus).

[0301] (2) Electron microscope observation condition setting Confirmation of the presence of agglomerates containing silica fine particles and a binding component is performed using the image obtained by backscattered electron image observation of Ultra Plus. In the backscattered electron image, the image contrast changes according to the elemental composition, so the presence of silica fine particles and the binding component in the agglomerates can be determined. The acceleration voltage is 0.7 kV, the ECB Grid is 500 V, and the WD is 3.0 mm.

[0302] (3) Focus adjustment Set the observation magnification to 30,000 (30k) times and adjust the Alignment and Stigma. Next, align the field of view with a region having a form considered to be an agglomerate at an appropriate observation magnification. From the obtained backscattered electron image, it can be determined that it is the same as the agglomerate for which composition observation was performed by STEM-EDX, having two types of contrasts, one corresponding to silica fine particles and the other corresponding to the binding component.

[0303] <Calculation method of the number of toner particles Ca, Cb having agglomerates when ultrasonic treatment is performed> Put about 10 ml of ion-exchanged water from which impurities and the like have been previously removed into a glass container. Add about 0.5 ml of a dilution obtained by diluting "Contaminon N" (a 10% by mass aqueous solution of a neutral detergent for precision measuring instruments with a pH of 7, composed of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) about 3-fold by mass with ion-exchanged water as a dispersant. Further add about 0.02 g of the measurement sample, and while stirring, perform the following dispersion treatment using an ultrasonic disperser to obtain a dispersion for measurement. At this time, appropriately cool so that the temperature of the dispersion is 10°C or higher and 40°C or lower. As the ultrasonic disperser, use an ultrasonic homogenizer with an oscillation frequency of 30 kHz ("VP-050" (manufactured by TAITEC)), insert the vibrating part 1.0 cm into the dispersion, and vibrate it under the following ultrasonic condition A or ultrasonic condition B. Ultrasonic condition A: Output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s Ultrasonic condition B: Output frequency 30 kHz, output capacity 35 W, irradiation time 300 s

[0304] Filter the dispersion obtained by the above procedure using a Kiriyama filter paper (No. 5C: pore diameter 1 μm) to separate the particles and the filtrate. Wash the obtained particles with 100 parts by mass of ion-exchanged water, and perform vacuum drying at 25°C for 24 hours to obtain a powder for measuring the number Ca and Cb of toner particles containing agglomerates.

[0305] Calculate Ca and Cb for the obtained powder by the same procedure as the "Method for Calculating the Number CI of Toner Particles Having Agglomerates", and confirm whether the relationships of the following formulas (1) and (2) are satisfied. 0.90 ≦ Ca / CI ≦ 1.00 Formula (1) 0.01 ≦ Cb / CI ≦ 0.10 Formula (2)

[0306] 〔Method for Measuring Physical Properties of Conductive Roller〕 Next, a method for confirming the structure of the conductive layer of the conductive roller and methods for measuring various physical properties will be described.

[0307] <Confirmation of Matrix-Domain Structure> The presence or absence of the formation of the matrix-domain structure in the conductive layer of the conductive roller is confirmed by the following method.

[0308] Using a razor, cut out a section (thickness: 500 μm) so that a cross-section perpendicular to the longitudinal direction of the conductive layer of the conductive roller can be observed. Next, perform platinum evaporation, and take a photograph at 1000 times magnification using a scanning electron microscope (SEM) (product name: S-4800, manufactured by Hitachi High-Technologies Corporation) to obtain a cross-sectional image.

[0309] In the section cut from the conductive layer, the matrix-domain structure observed shows a form in which a plurality of domains 6b are dispersed in the matrix 6a and exist independently without the domains being connected to each other in the cross-sectional image as shown in FIG. 2. 6c is an electron conductive agent within the domain. On the other hand, the matrix communicates within the image, and the domains are in a state of being separated by the matrix.

[0310] In the cross-sectional image, if a matrix-domain structure as shown in FIG. 2 can be confirmed, it is evaluated as "present", while if it does not have a matrix-domain structure, it is evaluated as "absent".

[0311] <Measurement of the volume resistivity R1 of the matrix> The volume resistivity R1 of the matrix can be measured, for example, by cutting out a thin slice of a predetermined thickness (for example, 1 μm) containing the matrix-domain structure from the conductive layer and bringing the microprobe of a scanning probe microscope (SPM) or an atomic force microscope (AFM) into contact with the matrix in the thin slice.

[0312] The cutting out of the thin slice from the elastic layer is performed, for example, as shown in FIG. 3(b). When the longitudinal direction of the conductive member is the X-axis, the thickness direction of the conductive layer is the Z-axis, and the circumferential direction is the Y-axis, the thin slice is cut out so as to include at least a part of a plane parallel to the YZ plane (for example, 83a, 83b, 83c) perpendicular to the axial direction of the conductive member. The cutting out can be performed, for example, using a sharp razor, a microtome, or a focused ion beam method (FIB).

[0313] For the measurement of volume resistivity, one side of a thin film cut from the conductive layer is grounded. Subsequently, a microprobe of a scanning probe microscope (SPM) or an atomic force microscope (AFM) is brought into contact with a matrix portion on the surface opposite to the grounded surface of the thin film, a DC voltage of 50 V is applied for 5 seconds, an arithmetic mean value is calculated from the value measured for the grounded current value for 5 seconds, and the electrical resistance value is calculated by dividing the applied voltage by the calculated value. Finally, using the film thickness of the thin film, the resistance value is converted into volume resistivity. At this time, SPM or AFM can also measure the film thickness of the thin film simultaneously with the resistance value.

[0314] The value of the volume resistivity R1 of the matrix in the columnar charging member is obtained, for example, by cutting out one thin film sample from each of the regions obtained by dividing the conductive layer into 4 parts in the circumferential direction and 5 parts in the longitudinal direction, obtaining the above measurement values, and then calculating the arithmetic mean value of the volume resistivity of a total of 20 samples.

[0315] In the examples described later, first, a thin film with a thickness of 1 μm was cut out from the conductive layer of the conductive member at a cutting temperature of -100°C using a microtome (trade name: Leica EM FCS, manufactured by Leica Microsystems). As shown in Fig. 3(b), the thin film was cut out so as to include at least a part of the YZ plane (for example, 83a, 83b, 83c) perpendicular to the axial direction of the conductive member when the longitudinal direction of the conductive member is the X axis, the thickness direction of the conductive layer is the Z axis, and the circumferential direction is the Y axis.

[0316] In an environment of temperature 23°C and humidity 50%RH, one surface of the thin film (hereinafter also referred to as the "grounded surface") was grounded on a metal plate, and a cantilever of a scanning probe microscope (SPM) (trade name: Q-Scope250, manufactured by Quesant Instrument Corporation) was brought into contact with a location corresponding to the matrix on the surface opposite to the grounded surface of the thin film (hereinafter also referred to as the "measurement surface") and where there is no domain between the measurement surface and the grounded surface. Subsequently, a voltage of 50 V was applied to the cantilever for 5 seconds, the current value was measured, and the arithmetic mean value for 5 seconds was calculated.

[0317] The surface shape of the measured section was observed with an SPM, and the thickness of the measurement location was calculated from the obtained height profile. Further, the recessed area of the contact portion of the cantilever was calculated from the observation result of the surface shape. The volume resistivity was calculated from the thickness and the recessed area.

[0318] For the thin flakes, the conductive layer was divided into five equal parts in the longitudinal direction and four equal parts in the circumferential direction, and 20 such sections were arbitrarily made, one point from each of the respective regions, and the above measurements were performed. The average value was taken as the volume resistivity R1 of the matrix.

[0319] Note that the scanning probe microscope (SPM) (trade name: Q-Scope250, manufactured by Quesant Instrument Corporation) was operated in the contact mode.

[0320] <Measurement of the volume resistivity R2 of the domain> In the measurement of the volume resistivity R1 of the above matrix, the volume resistivity R2 of the domain is measured in the same manner except that the measurement is carried out at a location corresponding to the domain of the ultra-thin section and the measurement voltage is set to 1V.

[0321] In the following examples, in the above (measurement of the volume resistivity R1 of the matrix), the location where the cantilever of the measurement surface is brought into contact is changed to a location corresponding to the domain and where there is no matrix between the measurement surface and the ground surface, and R2 is calculated in the same manner except that the applied voltage during the measurement of the current value is changed to 1V.

[0322] <Measurement of martensite hardness> The martensite hardness is measured using a microhardness tester (trade name: Picodenter HM500, manufactured by Helmut Fischer). Also, as the software, "WIN-HCU" (trade name) attached to the above surface coating physical property tester is used. The martensite hardness is a physical property value obtained by pushing a indenter into the measurement object while applying a load, and is obtained as (test load) / (surface area of the indenter under the test load) (N / mm 2 )

[0323] Press a indenter such as a quadrangular pyramid into the object to be measured while applying a predetermined relatively small test load, and when a predetermined penetration depth is reached, determine the surface area in contact with the indenter from the penetration depth at that time, and obtain the universal hardness from the following formula. In the present invention, the hardness when pressed in with a load of 1 mN is adopted.

[0324] Measure in accordance with ISO 14577 using a surface coating physical property tester (trade name: Pico-Denter HM500,). Take the arithmetic mean value of the Martens hardness measurements at 10 arbitrarily selected points in the central part of the conductive roller as the measured value of the developer carrier. The measurement conditions are shown below. · Measuring indenter: Quadrangular pyramid indenter (angle 136°, Berkovich type) · Indenter material: Diamond · Measurement environment: Temperature 23°C, relative humidity 50% · Load speed and unloading speed: 1 mN / 50 seconds · Maximum penetration load: 1 mN

[0325] Measure the load-hardness curve by loading the load at the speed described in the above conditions, and calculate the Martens hardness at the time when the penetration depth reaches 0.1 μm by the following calculation formula. Martens hardness HM (N / mm 2 ) = F (N) / Surface area of the indenter under the test load (mm 2 ) (In the formula, F represents force.)

[0326] <Measurement of Martens hardness G1 of the matrix part and Martens hardness G2 of the domain part> The measurement of the Martens hardness of the matrix part and the domain part is specifically carried out as follows. First, cut out a measurement sample including the outer surface of the conductive roller from the conductive roller to be measured with a razor. The measurement sample has a length of 2 mm each in the circumferential direction and the longitudinal direction of the conductive roller, and is cut out so as to have a thickness of 500 μm in the depth direction from the outer surface of the conductive roller.

[0327] Set the measurement sample on the microhardness tester so that the observation surface corresponding to the outer surface of the conductive roller of the obtained measurement sample can be observed. Then, observe the observation surface with a microscope (magnification: 50 times) attached to the microhardness tester, and arbitrarily select 10 points that are more than 0.1 μm away from the outer edge of any domain among the matrix parts. Bring the tip of the measurement indenter into contact with the 10 points, and measure the martensite hardness under the above-mentioned conditions. Let the arithmetic mean value of the 10 obtained measurement values be the martensite hardness G1 of the matrix part.

[0328] Similarly, observe the observation surface of the measurement sample, select any 10 domains, bring the measurement indenter into contact with the centroid position on the plane of each domain, and measure the martensite hardness under the above-mentioned conditions. Let the arithmetic mean value of the 10 obtained measurement values be the matrix hardness G2 of the domain part.

[0329] By comparing the martensite hardness values of the domain part and the matrix part obtained above, evaluate the magnitude relationship between the hardness of the domain part and the matrix part.

[0330] <Measurement of the equivalent circle diameter D of the domain observed from the cross-section of the conductive layer> The equivalent circle diameter D of the domain is calculated as follows.

[0331] When the length in the longitudinal direction of the conductive layer is L and the thickness of the conductive layer is T, a sample with a thickness of 1 μm having a surface on which cross-sections (83a, 83b, 83c) in the thickness direction of the conductive layer as shown in Fig. 3(b) appear is cut out from three locations: the center in the longitudinal direction of the conductive layer and L / 4 from both ends of the conductive layer toward the center, using a microtome (trade name: Leica EM FCS, manufactured by Leica Microsystems).

[0332] Platinum is vapor-deposited on the cross-section in the thickness direction of the conductive layer of each of the three obtained samples. Then, three arbitrarily selected locations within the thickness region from a depth of 0.1T to 0.9T from the outer surface of the conductive layer on the platinum-vapor-deposited surface of each sample are photographed at 5000 times magnification using a scanning electron microscope (SEM) (product name: S-4800, manufactured by Hitachi High-Technologies Corporation).

[0333] Each of the nine obtained photographed images is subjected to binarization and quantification by a counting function using image processing software (product name: ImageProPlus; manufactured by Media Cybernetics) to calculate the arithmetic mean value S of the area of the domains included in each photographed image.

[0334] Next, from the arithmetic mean value S of the area of the domains calculated for each photographed image, the equivalent circle diameter of the domain (=(4S / π) 0.5 ) is calculated. Next, the calculated average value of the equivalent circle diameters of the domains of each photographed image is calculated to obtain the equivalent circle diameter D of the domains observed from the cross-section of the conductive layer of the conductive roller to be measured.

[0335] <Measurement of the particle size distribution of the domains> The measurement of the particle size distribution of the domains for evaluating the uniformity of the equivalent circle diameter D of the domains is performed as follows. First, a binarized image is obtained by image processing software (product name: ImageProPlus; manufactured by Media Cybernetics) for the observation image at 5000 times magnification obtained by the scanning electron microscope (product name: S-4800, manufactured by Hitachi High-Technologies Corporation) obtained in the measurement of the equivalent circle diameter D of the above domains. Then, the average value D and the standard deviation σd are calculated for the domain group in the binarized image by the counting function of the image processing software, and then σd / D, which is an index of the particle size distribution, is calculated.

[0336] In the measurement of the σd / D particle size distribution of the domain diameter, when the length in the longitudinal direction of the conductive layer is L and the thickness of the conductive layer is T, cross-sections in the thickness direction of the conductive layer as shown in Fig. 3(b) are obtained at three locations: the center in the longitudinal direction of the conductive layer and at L / 4 from both ends of the conductive layer toward the center. For each of three arbitrary locations in the thickness region from a depth of 0.1T to 0.9T from the outer surface of the conductive layer for each of the three slices obtained from the above three measurement positions, a total of nine locations, a 50 μm square region is extracted as an analysis image for measurement, and the arithmetic mean value of the nine locations is calculated.

[0337] <Measurement of the domain spacing Dm observed from the cross-section of the conductive layer> When the length in the longitudinal direction of the conductive layer is L and the thickness of the conductive layer is T, a sample having a surface on which cross-sections (83a, 83b, 83c) in the thickness direction of the conductive layer as shown in Fig. 3(b) appear is obtained from the center in the longitudinal direction of the conductive layer and at three locations of L / 4 from both ends of the conductive layer toward the center.

[0338] For each of the three obtained samples, a 50 μm square analysis region is placed at three arbitrary locations in the thickness region from a depth of 0.1T to 0.9T from the outer surface of the conductive layer on the surface where the cross-section in the thickness direction of the conductive layer appears. The three analysis regions are photographed at a magnification of 5000 times using a scanning electron microscope (trade name: S-4800, manufactured by Hitachi High-Technologies Corporation). Each of the total nine photographed images obtained is binarized using image processing software (trade name: LUZEX; manufactured by Nireco Corporation).

[0339] The binarization procedure is performed as follows. The photographed image is subjected to 8-bit grayscale conversion to obtain a 256-tone monochrome image. Then, the black and white of the image is inverted so that the domains in the photographed image become white, and it is binarized to obtain a binarized image of the photographed image. Next, for each of the nine binarized images, the distance between the domain wall surfaces is calculated, and further, their arithmetic mean value is calculated. This value is taken as Dm. The "distance between wall surfaces" is the distance (shortest distance) between the wall surfaces of the closest domains, and can be obtained by setting the measurement parameter in the above image processing software as the distance between adjacent wall surfaces.

[0340] <Measurement of the uniformity of the domain-to-domain distance Dm> From the distribution of the wall-to-wall distances of the domains obtained in the process of measuring the domain-to-domain distance Dm, the standard deviation σm of the domain-to-domain distance is calculated, and the coefficient of variation σm / Dm, which is an index of the uniformity of the domain-to-domain distance, is calculated.

[0341] <Equivalent circle diameter Ds of the domains observed from the outer surface of the conductive layer> The equivalent circle diameter Ds of the domains observed from the outer surface of the conductive layer is measured as follows.

[0342] When the length of the conductive layer in the longitudinal direction is L, samples including the outer surface of the conductive layer are cut out from three locations: the center in the longitudinal direction of the conductive layer and L / 4 from both ends of the conductive layer toward the center, using a microtome (trade name: Leica EM FCS, manufactured by Leica Microsystems). The thickness of the sample is set to 1 μm.

[0343] Platinum is vapor-deposited on the surface of the sample corresponding to the outer surface of the conductive layer. Three arbitrary locations on the platinum-vapor-deposited surface of the sample are selected and photographed at 5000 times magnification using a scanning electron microscope (SEM) (trade name: S-4800, manufactured by Hitachi High-Technologies Corporation). Each of the total nine photographed images obtained is binarized and quantified by a counting function using image processing software (trade name: ImageProPlus; manufactured by Media Cybernetics) to calculate the arithmetic mean value Ss of the planar areas of the domains included in each photographed image.

[0344] Next, from the arithmetic mean value Ss of the planar areas of the domains calculated for each photographed image, the equivalent circle diameter of the domain (=(4S / π) 0.5 is calculated. Next, the calculated average value of the equivalent circle diameters of the domains in each photographed image is calculated to obtain the equivalent circle diameter Ds of the domains when the conductive roller to be measured is observed from the outer surface.

[0345] <Adjacent wall-to-wall distance Dms of the domains observed from the outer surface of the conductive roller> When the length in the longitudinal direction of the conductive layer is L and the thickness of the conductive layer is T, samples are cut out using a cutter from three locations: the center in the longitudinal direction of the conductive layer and L / 4 from both ends of the conductive layer toward the center so as to include the outer surface of the conductive roller. The size of the sample is 2 mm each in the circumferential direction and the longitudinal direction of the conductive roller, and the thickness is the thickness T of the conductive roller.

[0346] For each of the three obtained samples, analysis regions of 50 μm square are placed at any three locations on the surface corresponding to the outer surface of the conductive roller, and the three analysis regions are photographed at a magnification of 5000 times using a scanning electron microscope (trade name: S-4800, manufactured by Hitachi High-Technologies Corporation). Each of the total nine obtained photographed images is binarized using image processing software (trade name: LUZEX; manufactured by Nireco Corporation).

[0347] The binarization procedure is the same as the binarization procedure when obtaining the domain distance Dm described above. Next, for each of the binarized images of the nine photographed images, the distance between the walls of the domain is obtained, and further the arithmetic mean value thereof is calculated. This value is defined as Dms.

[0348] <Measurement of surface roughness Ra> Measurement is performed in accordance with the JIS B 0601-1994 standard for surface roughness using a surface roughness measuring instrument (trade name: SE-3500, manufactured by Kosaka Laboratory Ltd.). Ra is measured at six randomly selected locations on the surface of the conductive roller, and the arithmetic mean value thereof is taken. The cut-off value is 0.8 mm, and the evaluation length is 8 mm.

[0349] [Configuration included in the embodiment of the present invention] The disclosure of this embodiment includes the following configurations. (Configuration 1) A process cartridge having toner, a toner storage unit that stores the toner, an electrophotographic photoreceptor, charging means for charging the surface of the electrophotographic photoreceptor, cleaning means for removing residual toner in a region upstream of the charging means, and developing means for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor with toner to form a toner image on the surface of the electrophotographic photoreceptor, (I) The charging means has a conductive member disposed so as to be contactable with the electrophotographic photoreceptor, the cleaning means has a cleaning blade disposed so as to be contactable with the electrophotographic photoreceptor, the conductive member has a support having a conductive outer surface and a conductive layer provided on the outer surface of the support, the conductive layer having a matrix-domain structure having a matrix and a plurality of domains dispersed in the matrix, the matrix containing a first rubber, the domains containing a second rubber, and the surface of the conductive member having a surface roughness Ra of 2.00 μm or less, when the Martens hardness measured at a load of 1 mN in the matrix of the outer surface of the conductive member is G1 and the Martens hardness measured at a load of 1 mN in the domain of the outer surface of the conductive member is G2, both G1 and G2 are in the range of 1.0 N / mm 2 or more and 10.0 N / mm 2 or less, and the absolute value of the difference between G1 and G2 is 0.1 N / mm 2 or more and 7.0 N / mm 2 or less, (II) The toner has at least toner particles, and agglomerates containing silica fine particles and a binder component are present on the surface of the toner particles, when the number ratio of the toner particles having the agglomerates is CI (number %), the CI is 1 number % or more and 15 number % or less, when the number ratio of the toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition A is Ca (number %) and the number ratio of the toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition B is Cb (number %), the CI, the Ca, and the Cb satisfy the formulas (1) and (2), · Ultrasonic condition A: output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s · Ultrasonic condition B: output frequency 30 kHz, output capacity 35 W, irradiation time 300 s 0.90 ≦ Ca / CI ≦ 1.00 Formula (1) 0.01 ≦ Cb / CI ≦ 0.10 Formula (2) A process cartridge characterized in that an arithmetic mean value Dms of adjacent distances between domains present on the outer surface of a conductive roller and an arithmetic mean value Ag of the Feret diameters of the agglomerates satisfy the relationship Dms < Ag. (Configuration 2) The process cartridge according to Configuration 1, wherein, on the surface observed by a scanning electron microscope of toner particles having the agglomerates, the area ratio of the binding component of the agglomerates is 5% or more and 50% or less with respect to the entire aggregate. (Configuration 3) The process cartridge according to Configuration 1 or 2, wherein the martensitic hardnesses G1 and G2 satisfy the relationship G1 < G2. (Configuration 4) The process cartridge according to any one of Configurations 1 to 3, wherein the arithmetic mean value Dms of the closest distances between the domains is 200 nm or more and 2000 nm or less. (Configuration 5) The process cartridge according to any one of Configurations 1 to 4, wherein the arithmetic mean value Ag of the Feret diameters of the agglomerates is 1000 nm or more and 8000 nm or less. (Configuration 6) The process cartridge according to any one of Configurations 1 to 5, wherein the domain contains an electron conductive agent. (Configuration 7) The volume resistivity of the matrix is greater than 1.00×10 12 Ω·cm and less than or equal to 1.00×10 17 Ω·cm. The process cartridge according to any one of Configurations 1 to 6. (Configuration 8) The process cartridge according to any one of Configurations 1 to 7, wherein the toner contains a layered composite compound as an external additive. (Configuration 9) The process cartridge according to Configuration 8, wherein the layered composite compound contains fluorine. (Configuration 10) The process cartridge according to Configuration 8 or 9, wherein the layered composite compound is hydrotalcite. (Configuration 11) A process cartridge set having a first cartridge and a second cartridge that are detachable from the main body of an electrophotographic apparatus, (I) The first cartridge has a charging means for charging the surface of the electrophotographic photoreceptor, a cleaning means for removing residual toner in the region upstream of the charging means, and a first frame for supporting the charging means and the cleaning means. The second cartridge has a toner container containing toner for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor to form a toner image on the surface of the electrophotographic photoreceptor. (II) The charging means has a conductive member disposed so as to be in contact with the electrophotographic photoreceptor. The cleaning means has a cleaning blade disposed so as to be in contact with the electrophotographic photoreceptor. The conductive member has a support having a conductive outer surface and a conductive layer provided on the outer surface of the support. The conductive layer has a matrix-domain structure having a matrix and a plurality of domains dispersed in the matrix. The matrix contains a first rubber, the domains contain a second rubber, and the surface of the conductive member has a surface roughness Ra of 2.00 μm or less. When the Martens hardness measured at a load of 1 mN in the matrix of the outer surface of the conductive member is G1, and the Martens hardness measured at a load of 1 mN in the domain of the outer surface of the conductive member is G2, both G1 and G2 are within the range of 1.0 N / mm 2 or more and 10.0 N / mm 2 or less, and the absolute value of the difference between G1 and G2 is 0.1 N / mm 2 or more and 7.0 N / mm 2 or less. (III) The toner has at least toner particles, and agglomerates containing silica fine particles and a binder component are present on the surface of the toner particles. When the number ratio of toner particles having the agglomerates is CI (number %), the CI is 1% by number or more and 15% by number or less. When the percentage of toner particles having the agglomerates in the toner after being processed under the following ultrasonic condition A is Ca (number %), and the percentage of toner particles having the agglomerates in the toner after being processed under the following ultrasonic condition B is Cb (number %), the CI, the Ca, and the Cb satisfy the formulas (1) and (2), · Ultrasonic condition A: Output frequency 30 kHz, output power 0.75 W, irradiation time 300 s · Ultrasonic condition B: Output frequency 30 kHz, output power 35 W, irradiation time 300 s 0.90 ≦ Ca / CI ≦ 1.00 Formula (1) 0.01 ≦ Cb / CI ≦ 0.10 Formula (2) A process cartridge set, characterized in that the arithmetic mean value Dms of the adjacent distances between the domains present on the outer surface of the conductive roller and the arithmetic mean value Ag of the Feret diameters of the agglomerates satisfy the relationship Dms < Ag.

Example

[0350] The present invention will be specifically described by the following production examples and examples. However, these do not limit the present invention in any way. In the production examples and examples, "parts" are all based on mass unless otherwise specified.

[0351] A production example of toner particles will be described.

[0352] <Preparation of Resin Particle Dispersion Liquid 1> 78.0 parts of styrene, 20.7 parts of butyl acrylate, 1.3 parts of acrylic acid as a carboxyl group-introducing monomer, and 3.2 parts of n-lauryl mercaptan were mixed and dissolved. To this solution, an aqueous solution prepared by dissolving 2.0 parts of sodium linear alkylbenzene sulfonate (product name: Neogen RK (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)) in 150 parts of ion-exchanged water was added in its entirety and dispersed.

[0353] While stirring slowly for an additional 10 minutes, an aqueous solution of 0.3 part of potassium persulfate and 10 parts of ion-exchanged water was added. After nitrogen substitution, emulsion polymerization was carried out at 70 °C for 6 hours. After the polymerization was completed, the reaction solution was cooled to room temperature, and ion-exchanged water was added to obtain Resin Particle Dispersion Liquid 1 having a solid content concentration of 12.5% by mass and a median diameter of 0.2 μm on a volume basis.

[0354] <Preparation of Release Agent Dispersion Liquid 1> 100 parts of a release agent (behenyl behenate, melting point: 72.1 °C) and 15 parts of an aliphatic alcohol alkylene oxide adduct were mixed with 385 parts of ion-exchanged water, and dispersed using a wet jet mill JN100 (manufactured by Tokuyama Corporation) for about 1 hour to obtain Release Agent Dispersion Liquid 1. The concentration of Release Agent Dispersion Liquid 1 was 20% by mass.

[0355] <Preparation of Colorant Dispersion Liquid 1> 100 parts of carbon black “Nipex35 (manufactured by Orion Engineered Carbons)” as a colorant and 15 parts of an aliphatic alcohol alkylene oxide adduct were mixed with 885 parts of ion-exchanged water, and dispersed using a wet jet mill JN100 for about 1 hour to obtain Colorant Dispersion Liquid 1.

[0356] <Production Example of Toner Core Particle Dispersion Liquid 1> (Dispersion Step) 265 parts of Resin Particle Dispersion Liquid 1, 10 parts of Release Agent Dispersion Liquid 1, 10 parts of Colorant Dispersion Liquid 1, 2.9 parts of an aliphatic alcohol alkylene oxide adduct, and 0.6 part of sodium linear alkylbenzene sulfonate (Neogen RK) were dispersed using a homogenizer (Ultra Turrax T50 manufactured by IKA). While stirring, the temperature inside the container was adjusted to 30 °C, and a 1 mol / L aqueous sodium hydroxide solution was added to adjust the pH to 8.0.

[0357] (Aggregation Step) As a flocculant, an aqueous solution prepared by dissolving 0.08 part of aluminum chloride in 10 parts of ion-exchanged water was added over 10 minutes with stirring at 30°C. After leaving it standing for 3 minutes, the temperature was raised, and the temperature was raised to 50°C to form associated particles. In that state, the particle size of the associated particles was measured using a "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter). When the weight-average particle size reached 7.0 μm, 0.9 part of sodium chloride and 5.0 parts of aliphatic alcohol were added to stop particle growth.

[0358] A 1 mol / L aqueous sodium hydroxide solution was added to adjust the pH to 9.0, and then the temperature was raised to 95°C to sphericalize the aggregated particles. When the average circularity reached 0.980, the temperature was lowered, and it was cooled to room temperature to obtain toner core particle dispersion liquid 1.

[0359] <Production Example of Monomer Dispersion Liquid 1 Having Silica and Binder Component> 100 parts of styrene, 20 parts of methacryloxypropyltrimethoxysilane, and 100 parts of colloidal silica were dispersed using a homogenizer (manufactured by IKA: Ultra Turrax T50), the temperature inside the container was adjusted to 25°C, and monomer dispersion liquid 1 having silica and a binder component was obtained by stirring for 1 hour.

[0360] <Production Examples of Monomer Dispersion Liquids 2 to 12 Having Silica and Binder Component> In the preparation of monomer dispersion liquid 1 having silica and a binder component, monomer dispersion liquids 2 to 12 having silica and a binder component were obtained in the same manner except that the number of parts and the types of materials were changed as shown in Table 1.

[0361]

Table 1

[0362] <Production Example of Hydrotalcite 1> An aqueous mixed solution (Solution A) of 1.03 mol / L magnesium chloride and 0.239 mol / L aluminum sulfate, a 0.753 mol / L aqueous sodium carbonate solution (Solution B), and a 3.39 mol / L aqueous sodium hydroxide solution (Solution C) were prepared.

[0363] Next, Solution A, Solution B, and Solution C were added to a reaction tank using a metering pump at a flow rate such that the volume ratio of Solution A to Solution B was 4.5:1, and the pH value of the reaction solution was maintained in the range of 9.3 - 9.6 with Solution C. The reaction was carried out at 40°C to produce a precipitate. After filtration and washing, it was re-emulsified in ion-exchanged water to obtain a raw material hydrotalcite slurry. The hydrotalcite in the obtained hydrotalcite slurry had a concentration of 5.6% by mass.

[0364] The obtained hydrotalcite slurry was vacuum-dried at 40°C overnight. NaF was dissolved in ion-exchanged water to a concentration of 100 mg / L, and a solution adjusted to pH 7.0 using 1 mol / L HCl or 1 mol / L NaOH was prepared. The dried hydrotalcite was added thereto to a concentration of 0.1% (w / v%). Stirring was carried out at a constant speed for 48 hours using a magnetic stirrer so that it did not settle. Then, it was filtered through a membrane filter with a pore size of 0.5 μm and washed with ion-exchanged water. The obtained hydrotalcite was vacuum-dried at 40°C overnight and then subjected to a crushing treatment. The composition and physical properties of the obtained hydrotalcite 1 are shown in Table 2.

[0365] <Production Example of Hydrotalcite 2> An aqueous mixed solution (Solution A) of 1.03 mol / L magnesium chloride and 0.239 mol / L aluminum sulfate, a 0.753 mol / L aqueous sodium carbonate solution (Solution B), and a 3.39 mol / L aqueous sodium hydroxide solution (Solution C) were prepared.

[0366] Next, using metering pumps, liquid A, liquid B, and liquid C were poured into the reaction tank at a flow rate such that the volume ratio of liquid A to liquid B was 4.5:1, and the pH value of the reaction solution was maintained in the range of 9.3 - 9.6 with liquid C. The reaction was carried out at a reaction temperature of 40 °C to generate a precipitate. After filtration and washing, it was re-emulsified in ion-exchanged water to obtain a raw material hydrotalcite slurry. The hydrotalcite in the obtained hydrotalcite slurry had a concentration of 5.6% by mass. Then, it was filtered through a membrane filter with a pore size of 0.5 μm and washed with ion-exchanged water. The obtained hydrotalcite was vacuum dried at 40 °C overnight and then subjected to a crushing treatment. The composition and physical properties of the obtained hydrotalcite 2 are shown in Table 2.

[0367]

Table 2

[0368] Next, a toner production example will be described.

[0369] <Production Example of Toner 1> To 100 parts of the toner core particle dispersion liquid, 2.75 parts of the monomer dispersion liquid obtained by the above method and 0.005 part of potassium persulfate were added. The temperature inside the container was adjusted to 90 °C and stirred for 2 hours using a full-zone stirring blade to obtain toner particle dispersion liquid 1.

[0370] Hydrochloric acid was added to the obtained toner particle dispersion liquid 1 to adjust the pH to 1.5 or less, and it was stirred and left for 1 hour, then solid-liquid separation was performed using a pressure filter to obtain a toner cake. This was re-slurried with ion-exchanged water to form a dispersion liquid again, and then solid-liquid separation was performed using the aforementioned filter. The re-slurrying and solid-liquid separation were repeated until the electrical conductivity of the filtrate was 5.0 μS / cm or less, and finally solid-liquid separation was performed to obtain a toner cake. The obtained toner cake was dried and further classified using a classifier to obtain toner particles 1. The weight average particle diameter of the toner particles 1 was 6.9 μm.

[0371] 100 parts of toner particles and 0.4 part of hydrotalcite were put into an FM mixer (FM10C type manufactured by Nippon Coke Industry Co., Ltd.) through which water at 7°C was passed in the jacket. After the water temperature in the jacket was stabilized at 7°C ± 1°C, mixing was carried out at a peripheral speed of the rotating blades of 38 m / sec for 5 minutes to obtain toner mixture 1. At this time, the water flow rate in the jacket was appropriately adjusted so that the temperature inside the tank of the FM mixer did not exceed 25°C. The obtained toner mixture 1 was sieved with a mesh having an opening of 75 μm to obtain toner 1. The physical properties of the obtained toner 1 are shown in Table 3.

[0372] <Production Examples of Toners 2 to 14, 17 to 23> In the production example of toner 1, except that the number of parts, material types, and production conditions were changed as described in Table 3, toners 2 to 14, 17 to 23 were obtained in the same manner. The physical properties of the obtained toners 2 to 14, 17 to 23 are shown in Table 3.

[0373] <Production Example of Toner 15> To 100 parts of the toner core particle dispersion, 1.00 part of styrene, 0.25 part of methacryloxypropyltrimethoxysilane, 1.25 parts of colloidal silica, and 0.005 part of potassium persulfate were added. The temperature inside the container was adjusted to 90°C, and stirring was carried out for 2 hours using a full zone stirring blade to obtain toner particle dispersion 2.

[0374] Hydrochloric acid was added to the obtained toner particle dispersion 2 to adjust the pH to 1.5 or less, and it was stirred and left for 1 hour, followed by solid-liquid separation using a pressure filter to obtain a toner cake. This was reslurried with ion-exchanged water to form a dispersion again, and then solid-liquid separation was carried out using the aforementioned filter. Reslurrying and solid-liquid separation were repeated until the electrical conductivity of the filtrate became 5.0 μS / cm or less, and finally solid-liquid separation was carried out to obtain a toner cake. The obtained toner cake was dried and further classified using a classifier to obtain toner particles 2. The weight average particle diameter of the toner particles 2 was 6.9 μm.

[0375] 100 parts of toner particles and 0.4 parts of hydrotalcite were put into an FM mixer (FM10C type manufactured by Nippon Coke & Engineering Co., Ltd.) through which water at 7°C was passed in the jacket. After the water temperature in the jacket stabilized at 7°C ± 1°C, it was mixed at a peripheral speed of the rotating blades of 38 m / sec for 5 minutes to obtain toner mixture 15. At this time, the water flow rate in the jacket was appropriately adjusted so that the temperature inside the tank of the FM mixer did not exceed 25°C. The obtained toner mixture 15 was sieved with a mesh having an opening of 75 μm to obtain toner 15. The physical properties of the obtained toner 15 are shown in Table 3.

[0376] <Production Example of Toner 16> To 100 parts of the toner core particle dispersion, 1.25 parts of styrene, 1.25 parts of colloidal silica, and 0.005 parts of potassium persulfate were added. The temperature inside the container was adjusted to 90°C, and it was stirred for 2 hours using a full zone stirring blade to obtain toner particle dispersion 3.

[0377] Hydrochloric acid was added to the obtained toner particle dispersion 3 to adjust the pH to 1.5 or less, and it was stirred and left standing for 1 hour. Then, solid-liquid separation was performed using a pressure filter to obtain a toner cake. This was reslurried with ion-exchanged water to make it a dispersion again, and then solid-liquid separation was performed using the aforementioned filter. Reslurrying and solid-liquid separation were repeated until the electrical conductivity of the filtrate became 5.0 μS / cm or less, and finally, solid-liquid separation was performed to obtain a toner cake. The obtained toner cake was dried and further classified using a classifier to obtain toner particles 3. The weight average particle diameter of the toner particles 3 was 7.1 μm.

[0378] 100 parts of toner particles 3 and 0.4 parts of hydrotalcite were put into an FM mixer (FM10C type manufactured by Nippon Coke & Engineering Co., Ltd.) through which water at 7°C was passed in the jacket. After the water temperature in the jacket stabilized at 7°C ± 1°C, it was mixed at a peripheral speed of the rotating blades of 38 m / sec for 5 minutes to obtain toner mixture 16. At this time, the water flow rate in the jacket was appropriately adjusted so that the temperature inside the tank of the FM mixer did not exceed 25°C. The obtained toner mixture 16 was sieved with a mesh having an opening of 75 μm to obtain toner 16. The physical properties of the obtained toner 16 are shown in Table 3.

[0379]

Table 3

[0380] A manufacturing example of a conductive roller for the charging means of a process cartridge will be described.

[0381] <Manufacturing Example of Conductive Roller 1> (1. Preparation of Rubber Mixture for Forming Conductive Layer) [1-1. Preparation of Rubber Mixture for Domain Formation (CMB)] Each material shown in Table 4 was mixed at the compounding amounts shown in Table 4 using a 6-liter pressure kneader (trade name: TD6-15MDX, manufactured by Toshing Co., Ltd.) to obtain CMB. The mixing conditions were a filling rate of 70% by volume, a blade rotation speed of 30 rpm, and 30 minutes.

[0382]

Table 4

[0383] [1-2. Preparation of Rubber Mixture for Matrix Formation (MRC)] Each material shown in Table 5 was mixed at the compounding amounts shown in Table 5 using a 6-liter pressure kneader (trade name: TD6-15MDX, manufactured by Toshing Co., Ltd.) to obtain MRC. The mixing conditions were a filling rate of 70% by volume, a blade rotation speed of 30 rpm, and 16 minutes.

[0384]

Table 5

[0385] [1-3. Preparation of Unvulcanized Rubber Mixture for Forming Conductive Layer] The CMB and MRC obtained above were mixed at the compounding amounts shown in Table 6 using a 6-liter pressure kneader (trade name: TD6-15MDX, manufactured by Toshing Co., Ltd.). The mixing conditions were a filling rate of 70% by volume, a blade rotation speed of 30 rpm, and 20 minutes.

[0386]

Table 6

[0387] Next, with respect to 100 parts of the mixture of CMB and MRC, the vulcanizing agent and vulcanization accelerator shown in Table 7 were added in the compounding amounts shown in Table 7, and mixed using an open roll with a roll diameter of 12 inches (0.30 m) to prepare a rubber mixture for forming a conductive layer.

[0388] The mixing conditions were a front roll rotation speed of 10 rpm, a rear roll rotation speed of 8 rpm, a roll gap of 2 mm, and about 20 turnovers were performed in total. After that, the roll gap was set to 0.5 mm and 10 thin passes were performed.

[0389] [Table 7]

[0390] (2. Production of Conductive Roller) [2-1. Preparation of Support with Conductive Outer Surface] As a support with a conductive outer surface, a round bar with a total length of 252 mm and an outer diameter of 6 mm, which was subjected to electroless nickel plating on the surface of stainless steel (SUS), was prepared.

[0391] [2-2. Molding of Conductive Layer] A die with an inner diameter of 12.5 mm was attached to the tip of a crosshead extruder having a support supply mechanism and an unvulcanized rubber roller discharge mechanism. The temperature of the extruder and the crosshead was adjusted to 80°C, and the conveyance speed of the support was adjusted to 60 mm / sec. Under these conditions, the rubber mixture for forming a conductive layer was supplied from the extruder, and the outer peripheral portion of the support was coated with the rubber mixture for forming a conductive layer in the crosshead to obtain an unvulcanized rubber roller.

[0392] Next, the unvulcanized rubber roller was put into a hot air vulcanizing furnace at 160°C and heated for 60 minutes to vulcanize the rubber mixture for forming a conductive layer, and a roller with a conductive layer formed on the outer peripheral portion of the support was obtained. Thereafter, both ends of the conductive layer were each cut off by 12.25 mm, and the longitudinal length of the conductive layer portion was made 228 mm.

[0393] Finally, the surface of the conductive layer was polished with a rotary grinding wheel. As a result, a conductive roller 1 having a crown shape with a diameter of 8.44 mm at each position 90 mm from the central portion to both end portions and a central portion diameter of 8.5 mm was obtained.

[0394] <Manufacturing Examples of Conductive Rollers 2 to 9> Conductive rollers 2 to 9 were manufactured in the same manner as conductive roller 1, except that the materials and conditions shown in Tables 9-1 to 9-2 were used for the raw rubber, conductive agent, vulcanizing agent, and vulcanization accelerator.

[0395] Regarding the details of the materials shown in Tables 9-1 to 9-2, the rubber materials are shown in Table 10-1, the conductive agents are shown in Table 10-2, and the vulcanizing agents and vulcanization accelerators are shown in Table 10-3.

[0396] <Manufacturing Example of Comparative Conductive Roller 1> A conductive roller C1 was manufactured in the same manner as conductive roller 1, except that the materials and conditions shown in Tables 9-1 and 9-2 were used. Next, a conductive resin layer was provided on the conductive roller C1 according to the following method to manufacture a comparative conductive roller 1, and the same measurements and evaluations as those of the conductive roller 1 were performed.

[0397] (Formation of Conductive Resin Layer) Methyl isobutyl ketone was added as a solvent to the caprolactone-modified acrylic polyol solution and adjusted so that the solid content was 10% by mass. A mixed solution was prepared using the materials shown in Table 8 below for 1000 parts (100 parts of solid content) of this acrylic polyol solution. At this time, the mixture of blocked HDI and blocked IPDI was "NCO / OH = 1.0".

[0398]

Table 8

[0399] Next, 210 g of the above mixed solution and 200 g of glass beads having an average particle diameter of 0.8 mm as a medium were mixed in a 450 mL glass bottle, and pre-dispersed for 24 hours using a paint shaker disperser to obtain a paint for forming a conductive resin layer.

[0400] The conductive roller C1 was immersed in the paint for forming a conductive resin layer with its longitudinal direction being vertical, and was coated by the dipping method. The dipping time for dipping coating was 9 seconds, and the pulling-up speed was such that the initial speed was 20 mm / sec, the final speed was 2 mm / sec, and the speed was linearly changed with respect to time in between.

[0401] The obtained coated article was air-dried at room temperature for 30 minutes, then dried in a hot air circulation dryer set at 90°C for 1 hour, and further dried in a hot air circulation dryer set at 160°C for 1 hour to obtain Comparative Conductive Roller 1.

[0402] <Manufacturing Examples of Comparative Conductive Rollers 2 and 3> Except for using the materials and conditions shown in Table 9-1 and Table 9-2, Comparative Conductive Rollers 2 to 3 were manufactured in the same manner as in Example 1, and the same measurements and evaluations as in Example 1 were performed.

[0403] The physical properties of the manufactured Conductive Rollers 1 to 6 and Comparative Conductive Rollers 1 to 3 are shown in Table 11.

[0404]

Table 9-1

[0405] Regarding the Mooney viscosity in the table, the Mooney viscosity of the raw materials is the catalog value of each company, and the Mooney viscosity of the mixture is the Mooney viscosity ML (1+4) measured at the rubber temperature during kneading. The unit of the SP value is (J / cm 3 ) 0.5 and DBP indicates the DBP oil absorption amount (cm 3 / 100 g).

[0406]

Table 9-2

[0407] Regarding the Mooney viscosity in the table, the Mooney viscosity of the raw materials is the catalog value of each company, and the Mooney viscosity of the mixture is the Mooney viscosity ML (1+4) measured at the rubber temperature during kneading.

[0408]

Table 10-1

[0409]

Table 10-2

[0410]

Table 10-3

[0411]

Table 11

[0412] In the table, the MD structure indicates the presence or absence of the matrix domain structure.

[0413] 〔Example 1〕 HP Color Laser jet Enterprise M653dn was prepared as an electrophotographic apparatus. Next, a process cartridge filled with Toner 1, a conductive roller 1, and the electrophotographic apparatus were left in a normal temperature and humidity environment (25°C / 50%RH) for 48 hours for the purpose of acclimating to the measurement environment.

[0414] The conductive roller 1 left in the above environment was set as the charging roller of the process cartridge, incorporated into the M653dn, and evaluated.

[0415] The combination of these electrophotographic apparatuses and process cartridges corresponds to the configuration shown in FIG. 5.

[0416] Note that the M653dn was modified to a process speed of 400 mm / s and used in consideration of further future high-speed and long-life performance of the printer. As the evaluation paper, A4 color laser copy paper (manufactured by Canon, 80 g / m 2 ) was used.

[0417] <Evaluation of Image Streaks (Contamination Streaks) Caused by Cleaning Defects> The evaluation of image streaks caused by cleaning defects was carried out in a normal temperature and humidity environment (25°C / 50%RH). Assuming a long-term durability test, a horizontal line pattern with a printing rate of 1% was set as 2 sheets / 1 job, and the machine was set to stop once between jobs and then start the next job. In this mode, a total of 30,000 sheets of drawing tests were carried out, and the number of streaks caused by toner that passed through the cleaning on the electrophotographic roller was measured. In this disclosure, it was determined that there was no practical problem if it was B rank or higher as follows. A: 0 streaks. B: 1 streak. C: 2 - 3 streaks. D: 4 or more streaks.

[0418] <Evaluation of Charging Roller Contamination and Density Unevenness> The evaluation of charging roller contamination was carried out in a normal temperature and humidity environment (25°C / 50%RH). Assuming a long-term durability test, a horizontal line pattern with a printing rate of 1% was set as 2 sheets / 1 job, and the machine was set to stop once between jobs and then start the next job. In this mode, a total of 30,000 sheets of drawing tests were carried out, and after the implementation, the surface of the charging roller and the halftone image were visually observed and evaluated based on the following evaluation criteria. In this disclosure, it was determined that there was no practical problem if it was B rank or higher as follows. A: No defects are observed on either the surface of the conductive roller or the image. B: Slight dirt is observed on the surface of the conductive roller, but it does not appear in the image. C: Dirt is observed on the surface of the conductive roller, and image density unevenness is also starting to be noticeable. D: Dirt on the surface of the conductive roller is observed, and it can be confirmed that density unevenness clearly occurs in the image.

[0419] <Evaluation of Charge Rise Property (Ghosting after Standing in H / H Environment)> The evaluation of the charge rise property was carried out in a high-temperature and high-humidity environment (30°C / 80%RH) where the charge rise property is disadvantageous. The evaluation was performed using a modified HP Color Laser jet Enterprise M653dn placed in the above environment. First, initially, a full-white image was printed on an evaluation paper with a Post-it note attached around the center bottom, and the density difference between the part hidden by the Post-it note and the other part was taken as the initial ghosting value. Assuming a long-term durability test, a horizontal line pattern with a printing rate of 1% was set at 2 sheets / 1 job, and the machine was set to stop once between jobs and then start the next job. In this mode, a total of 35,000 sheets of printing tests were carried out. Immediately after 30,000 sheets of printing were completed, the power of the machine was turned off, and the developer was left inside the machine for 72 hours. After leaving it, the power of the machine was turned on again, and an image similar to the initial ghosting was printed, and the density difference was taken as the value of the ghosting after standing. A reflectometer (Reflectometer Model TC-6DS manufactured by Tokyo Denshoku Co., Ltd.) was used, and an amber light filter was used for the filter. The evaluation criteria were set as follows. In this disclosure, it was determined that there was no practical problem if it was at or above the following Grade C. A: Less than 2.0 B: 2.0 or more and less than 3.0 C: 3.0 or more and less than 4.0 D: 4.0 or more

[0420] 〔Examples 2 to 23, Comparative Examples 1 to 9〕 The evaluation was carried out in the same manner as in Example 1 except that the conductive roller and the toner to be filled were changed as shown in Table 12. The evaluation results are shown in Table 12.

[0421]

Table 12

Explanation of Reference Signs

[0422] 51: Conductive roller, 52: Support, 53: Conductive layer, 81: Conductive roller, 91: Electro-photographic photoreceptor, 92: Charging means, 93: Developing means, 95: Cleaning means, 96: Toner storage section, 99: Toner

Claims

1. A process cartridge having a toner, a toner container for containing the toner, an electrophotographic photoreceptor, charging means for charging the surface of the electrophotographic photoreceptor, cleaning means for removing residual toner in a region upstream of the charging means, and developing means for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor with toner to form a toner image on the surface of the electrophotographic photoreceptor, wherein (I) the charging means has a conductive member disposed so as to be contactable with the electrophotographic photoreceptor, the cleaning means has a cleaning blade disposed so as to be contactable with the electrophotographic photoreceptor, the conductive member has a support having a conductive outer surface and a conductive layer provided on the outer surface of the support, the conductive layer having a matrix-domain structure having a matrix and a plurality of domains dispersed in the matrix, the matrix containing a first rubber, the domains containing a second rubber, and the surface of the conductive member having a surface roughness Ra of 2.00 μm or less, The Martens hardness when measured at a load of 1 mN in the matrix of the outer surface of the conductive member is defined as G1, and the Martens hardness when measured at a load of 1 mN in the domain of the outer surface of the conductive member is defined as G2. Both G1 and G2 are 1.0 N / mm 2 10.0N / mm or more 2 Within the range below, and the absolute value of the difference between G1 and G2 is 0.1 N / mm 2 7.0N / mm or more 2 is as follows: wherein (II) the toner has at least toner particles, and agglomerates containing silica fine particles and a binder component are present on the surface of the toner particles, when the number ratio of the toner particles having the agglomerates is CI (number %), the CI is 1% or more and 15% or less, when the number ratio of the toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition A is Ca (number %), and the number ratio of the toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition B is Cb (number %), the CI, the Ca, and the Cb satisfy the formulas (1) and (2), - Ultrasonic condition A: output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s - Ultrasonic condition B: output frequency 30 kHz, output capacity 35 W, irradiation time 300 s 0.90 ≦ Ca / CI ≦ 1.00 Formula (1) 0.01 ≦ Cb / CI ≦ 0.10 Formula (2) A process cartridge, characterized in that the arithmetic mean value Dms of the adjacent distances between the domains present on the outer surface of the conductive roller and the arithmetic mean value Ag of the Feret diameters of the agglomerates satisfy the relationship Dms < Ag.

2. The process cartridge according to claim 1, wherein, on the surface observed by a scanning electron microscope of the toner particles having the agglomerates, the area ratio of the binder component of the agglomerates is 5% or more and 50% or less with respect to the entire aggregate.

3. The process cartridge according to claim 1 or 2, wherein the martensite hardnesses G1 and G2 satisfy the relationship G1 < G2.

4. The process cartridge according to claim 1 or 2, wherein the arithmetic mean value Dms of the adjacent distances between the domains is 200 nm or more and 2000 nm or less.

5. The process cartridge according to claim 1 or 2, wherein the arithmetic mean value Ag of the Feret diameters of the agglomerates is 1000 nm or more and 8000 nm or less.

6. The process cartridge according to claim 1 or 2, wherein the domain contains an electron conductive agent.

7. The volume resistivity of the matrix is greater than 1.00×10 12 Ω·cm and less than or equal to 1.00×10 17 Ω·cm, the process cartridge according to claim 1 or 2.

8. The process cartridge according to claim 1 or 2, wherein the toner contains a layered composite compound as an external additive.

9. The process cartridge according to claim 8, wherein the layered composite compound contains fluorine.

10. The process cartridge according to claim 8, wherein the layered composite compound is hydrotalcite.

11. A process cartridge set having a first cartridge and a second cartridge that are detachable from the main body of an electrophotographic apparatus, (I) The first cartridge has a charging means for charging the surface of the electrophotographic photoreceptor, a cleaning means for removing residual toner in a region upstream of the charging means, and a first frame for supporting the charging means and the cleaning means. The second cartridge has a toner container that contains toner for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor to form a toner image on the surface of the electrophotographic photoreceptor. (II) The charging means has a conductive member disposed in contact with the electrophotographic photoreceptor. The cleaning means has a cleaning blade disposed in contact with the electrophotographic photoreceptor. The conductive member has a support having a conductive outer surface and a conductive layer provided on the outer surface of the support. The conductive layer has a matrix-domain structure having a matrix and a plurality of domains dispersed in the matrix. The matrix contains a first rubber, the domain contains a second rubber, and the surface of the conductive member has a surface roughness Ra of 2.00 μm or less. When the Martens hardness measured at a load of 1 mN in the matrix on the outer surface of the conductive member is designated as G1, and the Martens hardness measured at a load of 1 mN in the domain on the outer surface of the conductive member is designated as G2, both G1 and G2 are in the range of 2 1.0 N / mm or more and 2 10.0 N / mm or less, and the absolute value of the difference between G1 and G2 is 2 7.0 N / mm or more and 2 less than (III) The toner has at least toner particles, and agglomerates containing silica fine particles and a binder component are present on the surface of the toner particles. When the number ratio of toner particles having the agglomerates is CI (number %), the CI is 1% to 15% by number, when the number ratio of toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition A is Ca (number %), and the number ratio of toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition B is Cb (number %), the CI, the Ca, and the Cb satisfy the formulas (1) and (2), - Ultrasonic condition A: output frequency 30 kHz, output power 0.75 W, irradiation time 300 s - Ultrasonic condition B: output frequency 30 kHz, output power 35 W, irradiation time 300 s 0.90 ≤ Ca / CI ≤ 1.00 Formula (1) 0.01 ≤ Cb / CI ≤ 0.10 Formula (2) A process cartridge set, characterized in that the arithmetic mean value Dms of the adjacent distances between domains present on the outer surface of the conductive roller and the arithmetic mean value Ag of the Feret diameters of the agglomerates satisfy the relationship Dms < Ag.

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