Electrophotographic member and electrophotographic image forming device

Abstract

To provide an electrophotographic member having excellent transferability over a long period of time.SOLUTION: An electrophotographic member comprising a base layer and a surface layer on the base layer, the surface layer containing at least one selected from the group consisting of a (meth)acrylic resin and a (meth)acrylic rubber, a plurality of resin particles being present on an outer surface of the surface layer, at least some of the plurality of resin particles being in direct contact with the outer surface of the surface layer, a part of the outer surface of the electrophotographic member being composed of the resin particles, irregularities formed by the resin particles being present on the outer surface of the electrophotographic member, and the resin particles containing a (meth)acrylic-modified silicone resin.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an electrophotographic member used in an electrophotographic image forming apparatus such as a copying machine or a printer, and to the electrophotographic image forming apparatus. [Background technology]

[0002] Electrophotographic image forming apparatuses capable of forming color images widely use a tandem method in which toner images of each color of YMCK are superimposed on an intermediate transfer belt, which is an electrophotographic belt, and then transferred all at once onto paper to obtain a full-color image. In such image forming apparatuses, an intermediate transfer belt having at least one elastic layer (hereinafter also referred to as an elastic intermediate transfer belt) may be used to further improve image quality. Elastic intermediate transfer belts having an elastic layer as a surface layer may not have sufficient toner releasability and may reduce transfer efficiency, so a configuration in which resin particles are embedded in the outer surface of the elastic layer and exposed to the surface may be used.

[0003] Patent Document 1 discloses a configuration in which an acrylic rubber is used as the elastic layer and silicone resin particles with excellent toner releasability are used as the resin particles on the outer surface. Patent Document 2 discloses a configuration in which an acrylic rubber is used as the elastic layer and acrylic resin particles in addition to silicone resin particles are used as the resin particles embedded in the outer surface of the elastic layer, thereby further improving transferability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-208485 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-145817 Summary of the Invention [Problem to be solved by the invention]

[0005] However, according to the study by the present inventors, in the case of a configuration in which acrylic rubber is used as the elastic layer and silicone resin particles are used as the resin particles as disclosed in Patent Documents 1 and 2, the silicone resin particles may fall off during long-term use, which may result in a decrease in transferability over long-term use, even if the transferability is excellent at the start of use. Furthermore, as disclosed in Patent Document 2, when acrylic resin particles are used, the acrylic resin particles do not detach, but the toner release effect of the acrylic resin particles is weaker than that of silicone resin particles, and transferability may deteriorate.

[0006] At least one aspect of the present disclosure is directed to providing an electrophotographic member that exhibits excellent transferability over a long period of time by achieving both high levels of toner releasability and high levels of adhesion between a surface layer and inorganic particles. Also, at least one aspect of the present disclosure is directed to providing an electrophotographic image forming apparatus that can stably form high-quality electrophotographic images. [Means for solving the problem]

[0007] According to at least one aspect of the present disclosure, 1. An electrophotographic member having a base layer and a surface layer on the base layer, the surface layer contains at least one selected from the group consisting of a (meth)acrylic resin and a (meth)acrylic rubber, a plurality of resin particles are present on the outer surface of the surface layer, at least some of the plurality of resin particles are in direct contact with the outer surface of the surface layer; a part of an outer surface of the electrophotographic member is made of the resin particles, and the outer surface of the electrophotographic member has irregularities formed by the resin particles; An electrophotographic member is provided, wherein the resin particles comprise a (meth)acrylic-modified silicone resin.

[0008] According to at least one aspect of the present disclosure, an image forming unit including an image carrier, a charging means, an image exposure means, and a developing means; an intermediate transfer member; a primary transfer member that primarily transfers the toner image formed on the image carrier onto the intermediate transfer member; a secondary transfer member that secondarily transfers the toner image on the intermediate transfer member onto a recording material, The developing means includes a toner storage section that stores toner, An electrophotographic image forming apparatus is provided in which the intermediate transfer member is the electrophotographic member of the present disclosure. [Effects of the Invention]

[0009] According to at least one aspect of the present disclosure, there is provided an electrophotographic member having excellent transferability over a long period of time, and also, according to at least one aspect of the present disclosure, there is provided an electrophotographic image forming apparatus capable of stably forming high-quality electrophotographic images. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a cross section of an electrophotographic member according to one aspect of the present disclosure. [Figure 2] 1 is a schematic cross-sectional view of an image forming apparatus using an electrophotographic member according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] In the present disclosure, expressions such as "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the endpoints, that is, the lower and upper limits, unless otherwise specified. When a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined. Furthermore, in the present disclosure, expressions such as "at least one selected from the group consisting of XX, YY, and ZZ" mean any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ. Note that when XX is a group, multiple XXs may be selected, and the same applies to YY and ZZ. In the present disclosure, (meth)acrylic resin refers to an acrylic resin and / or a methacrylic resin, (meth)acrylic rubber refers to an acrylic rubber and / or a methacrylic rubber, (meth)acrylate refers to an acrylate and / or a methacrylate, and (meth)acrylic-modified silicone resin refers to an acrylic-modified silicone resin and / or a methacrylic-modified silicone resin. In the present disclosure, the unit of surface resistance, Ω / □, indicates Ω / square.

[0012] Hereinafter, an electrophotographic member and an electrophotographic image forming apparatus according to an embodiment of the present disclosure will be described in detail with reference to the drawings. However, the scope of the present disclosure is not limited to this embodiment, and modifications within the scope of the present disclosure are also included in the present disclosure.

[0013] At least one aspect of the present disclosure is 1. An electrophotographic member having a base layer and a surface layer on the base layer, the surface layer contains at least one selected from the group consisting of a (meth)acrylic resin and a (meth)acrylic rubber, a plurality of resin particles are present on the outer surface of the surface layer, at least some of the plurality of resin particles are in direct contact with the outer surface of the surface layer; a part of an outer surface of the electrophotographic member is made of the resin particles, and the outer surface of the electrophotographic member has irregularities formed by the resin particles; The resin particles relate to an electrophotographic member comprising a (meth)acrylic-modified silicone resin.

[0014] 1, an electrophotographic member according to one embodiment of the present disclosure has at least a base layer 101 and a surface layer 102 on the base layer. A plurality of resin particles 103 are present on the outer surface of the surface layer 102. At least some of the plurality of resin particles 103 are in direct contact with the outer surface of the surface layer 102. As a result, at least some of the plurality of resin particles 103 are provided on the outer surface of the surface layer 102. The outer surface of the surface layer 102 is the surface of the surface layer opposite to the surface facing the base layer. A portion of the outer surface of the electrophotographic member is made up of the resin particles 103, and the outer surface of the electrophotographic member has irregularities formed by the resin particles. As a result, excellent transferability is obtained. The resin particles 103 are preferably arranged independently in the planar direction on the outer surface of the surface layer 102. It is also preferable that the resin particles 103 form a substantially single layer with almost no overlapping of the resin particles 103 in the layer thickness direction or complete immersion of the resin particles 103 in the surface layer 102. In other words, it is preferable that the resin particles 103 on the outer surface of the surface layer 102 form a substantially single layer.

[0015] (base layer) The base layer 101 will now be described. The shape of the base layer 101 is not particularly limited, but may be, for example, a roll or belt shape, or a seamless cylindrical shape. An endless cylindrical shape is also preferred. The material of the base layer 101 is not particularly limited, but examples thereof include the following: resins such as polyether ether ketone, polyethylene terephthalate, polybutylene naphthalate, polyester, polyimide, polyamide, polyamideimide, polyacetal, and polyphenylene sulfide. Among these, at least one selected from the group consisting of polyether ether ketone and polyimide is preferred, and polyimide is more preferred from the viewpoints of mechanical strength and heat resistance. The content of the resin in the base layer is not particularly limited, but may be 75 to 100% by mass, or 75 to 90% by mass.

[0016] The base layer 101 preferably contains a conductive powder such as metal powder, conductive oxide powder, or conductive carbon black. By containing a conductive powder, the base layer is more likely to have conductivity. Of these, conductive carbon black is preferred. The content of the conductive powder in the base layer is not particularly limited, but may be 10 to 25 mass %. From the viewpoint of obtaining excellent mechanical strength and electrical conductivity, polyether ether ketone or polyimide containing carbon black is particularly preferred as the material for the base layer.

[0017] The thickness of the base layer 101 is not particularly limited and can be appropriately selected depending on the purpose. Considering use as an intermediate transfer member, the thickness is preferably 10 μm or more and 500 μm or less, and more preferably 30 μm or more and 200 μm or less. If the thickness is 10 μm or more, the mechanical strength is likely to be improved. Also, if the thickness is 500 μm or less, suitable rigidity is likely to be obtained.

[0018] (Surface layer) A surface layer 102 is formed on the base layer 101. That is, the surface layer 102 is formed on the outer peripheral surface of the base layer 101. The surface layer 102 is not particularly limited, but may be a resin layer. The elastic layer is preferable, and more preferable is an elastic layer. The elastic layer allows the toner on the outer surface of the electrophotographic member to easily follow the surface irregularities of the recording material such as paper. The material for the elastic layer is not particularly limited, but it is preferable that the elastic layer contains (meth)acrylic rubber, from the viewpoint that the elastic layer has high flexibility, high adhesion to resin particles, and high environmental stability, which facilitates excellent transferability over a long period of time. The content of the (meth)acrylic rubber in the elastic layer is not particularly limited, but may be 90 to 99% by mass.

[0019] The (meth)acrylic rubber is not particularly limited and may be any known rubber. Examples of commercially available products include the Nipol (trade name, manufactured by Zeon Corporation) series and the AREX (trade name, manufactured by JSR Corporation) series.

[0020] The (meth)acrylic rubber preferably has a structure represented by the following formula (1). [ka] In formula (1), R1 represents a methyl group or a hydrogen atom, and R2 represents an alkyl group having 1 to 18 carbon atoms (preferably 1 to 12, more preferably 1 to 9), or an alkyl group having 2 to 18 carbon atoms (preferably 2 to 12, more preferably 2 to 9) and an ether bond. The alkyl group represented by R2 may have any substituent.

[0021] The alkyl group having 2 to 18 carbon atoms and an ether bond is a functional group in which a methylene group in the alkyl group is substituted with oxygen. For example, R2 may have a structure represented by the following formula (1-1). -Ra-O-Rb (1-1) In formula (1-1), Ra represents an alkylene group having 1 to 17 carbon atoms (preferably 1 to 11, more preferably 1 to 8), Rb represents an alkyl group having 1 to 17 carbon atoms (preferably 1 to 11, more preferably 1 to 8), and the sum of the number of carbon atoms in Ra and the number of carbon atoms in Rb is 2 to 18 (preferably 2 to 12, more preferably 2 to 9).

[0022] The method for obtaining the elastic layer is not particularly limited, but examples thereof include a method of preparing a rubber composition containing a (meth)acrylic rubber, preparing a solution containing the rubber composition and a solvent, applying the solution to a base layer, and evaporating the solvent.

[0023] The (meth)acrylic rubber may contain a conductive agent for adjusting electrical properties, and, if necessary, additives such as a crosslinking accelerator, a crosslinking retarder, a crosslinking aid, a vulcanizing agent, a flame retardant, a flame retardant aid, an ultraviolet absorber, and a rust inhibitor, which may be used alone or in combination. The total content of additives in the (meth)acrylic rubber is not particularly limited, but may be 0.1 to 5% by mass.

[0024] The elastic layer preferably contains a conductive agent. The conductive agent is not particularly limited, but examples thereof include an electronic conductive agent and an ionic conductive agent. The ionic conductive agent is not particularly limited, but potassium bis(trifluoromethanesulfonyl)imide is preferred. The content of the conductive agent in the elastic layer is not particularly limited, but may be 0.1 to 1% by mass.

[0025] The electrical resistivity of the elastic layer is not particularly limited. For example, the surface resistivity of the elastic layer is 1×10 8 ~1×10 14 It is preferable that the volume resistivity of the elastic layer is 1×10 6 ~1×10 13 It is preferably Ω·cm. For example, when the elastic layer contains a conductive agent, the electrical resistivity of the elastic layer can be adjusted by the amount of the conductive agent.

[0026] The thickness of the elastic layer is not particularly limited, but is preferably 100 μm to 2 mm, and more preferably 400 μm to 1 mm. If the thickness is less than 100 μm, the ability to conform to the unevenness of the paper may decrease, and transferability may decrease. On the other hand, if the thickness is greater than 2 mm, cracks may easily occur due to bending at the roller portion for tensioning the electrophotographic member, and image quality may decrease.

[0027] From the viewpoint of achieving both good conformability to paper irregularities and good toner releasability and maintaining high image quality, the elastic deformation power ηIT of the electrophotographic member is preferably 60% to 90%. Specifically, when a Vickers indenter is placed in contact with the outer surface of the elastic layer and a nanoindentation test of the elastic layer according to ISO 14577 is performed with a test load of 120 μN to obtain a load-displacement curve, the elastic deformation power ηIT calculated from the load-displacement curve is preferably 60% to 90%. A test load of 120 μN can correspond to the load when toner is pressed into the electrophotographic member in an electrophotographic image forming apparatus. Furthermore, the elastic deformation power of the electrophotographic member being equal to or greater than a certain level indicates that the member maintains its elasticity when unloaded and easily returns to its original shape. When the elastic deformation power is within the above range, the deformed surface layer does not permanently deform and returns to its original state, thereby reducing the contact area between the toner and the surface layer. This is thought to improve toner releasability and further improve transferability. For example, when the elastic layer contains an additive, the elastic deformation power η IT can be adjusted by changing the content of the additive, such as a vulcanizing agent.

[0028] As described above, the surface layer is preferably a resin layer. The resin layer is a layer containing a resin. The resin is not particularly limited, but a (meth)acrylic resin is preferred. The content of the resin in the resin layer is not particularly limited, but may be 70 to 100% by mass, or 70 to 90% by mass.

[0029] The method for obtaining the resin layer is not particularly limited, and examples thereof include a method of preparing a solution containing a (meth)acrylic resin and a solvent, applying the solution to a base layer, and evaporating the solvent. Alternatively, a resin layer can be formed by preparing a solution containing a polymerizable monomer for forming a (meth)acrylic resin and a solvent, applying the solution to a base layer, evaporating the solvent, and polymerizing the polymerizable monomer on the base layer.

[0030] The polymerizable monomer is not particularly limited, but examples thereof include (meth)acrylic acid and (meth)acrylate, and among these, (meth)acrylate is preferred. The (meth)acrylate is not particularly limited, and examples thereof include monofunctional (meth)acrylates such as hexyl (meth)acrylate, cyclohexyl (meth)acrylate, and benzyl (meth)acrylate; and polyfunctional (meth)acrylates having two or more functional groups such as 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. Among them, it is preferable to use a polyfunctional (meth)acrylate having three or more functional groups such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate, and it is preferable to use at least one polyfunctional (meth)acrylate selected from the group consisting of trimethylolpropane tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. By using a polyfunctional (meth)acrylate, the strength of the resin layer is likely to be improved.

[0031] A polymerization initiator may be used as needed to carry out the polymerization. Examples of the polymerization initiator include radical polymerization initiators such as alkylphenones and acylphosphine oxides, cationic polymerization initiators such as aromatic sulfonium salts, and anionic polymerization initiators such as nifedipine.

[0032] The structure of the (meth)acrylic resin is not particularly limited, but it is preferable that the (meth)acrylic resin has a structure represented by the following formula (1'). [ka] In formula (1'), R7 represents a methyl group or a hydrogen atom, and R8 represents an alkyl group having 1 to 18 carbon atoms (preferably 1 to 12, more preferably 1 to 9), or an alkyl group having 2 to 18 carbon atoms (preferably 2 to 12, more preferably 2 to 9) and an ether bond. The alkyl group represented by R8 may have any substituent.

[0033] The alkyl group having 2 to 18 carbon atoms and an ether bond is a functional group in which a methylene group in the alkyl group is substituted with oxygen. That is, R8 may have the structure represented by the above formula (1-1), similar to the above R2.

[0034] The resin layer may also contain other known additives such as a conductive agent, an antioxidant, a leveling agent, a crosslinking agent, and a flame retardant. The total content of the additives in the resin layer is not particularly limited, but may be 1 to 30% by mass.

[0035] The thickness of the resin layer is not particularly limited, but is preferably 1 to 20 μm, and more preferably 2 to 10 μm. If the thickness is less than 1 μm, the effect of the resin layer is likely to be reduced due to wear and tear during long-term use. If the thickness is greater than 20 μm, cracks are likely to occur due to bending at the roller portion for stretching the electrophotographic member, which may result in a decrease in image quality. The thickness of the resin layer can be adjusted by adjusting the conditions for forming the resin layer, such as the solid content concentration and the film formation rate.

[0036] (resin particles) Next, the resin particles 103 will be described. The resin particles 103 contain a (meth)acrylic-modified silicone resin. By containing the (meth)acrylic-modified silicone resin, the electrophotographic member has excellent adhesion to the (meth)acrylic rubber and (meth)acrylic resin that may be contained in the surface layer, as well as excellent toner releasability. The reason for this excellent adhesion is thought to be that the (meth)acrylic-modified silicone resin has a structure similar to the structure contained in the (meth)acrylic rubber and the structure contained in the (meth)acrylic resin, and is therefore compatible with the (meth)acrylic rubber and the (meth)acrylic resin. In addition, the reason for this excellent releasability is thought to be that the (meth)acrylic-modified silicone resin has a silicone skeleton. The content of the (meth)acrylic-modified silicone resin in the resin particles is not particularly limited, but may be 95 to 100% by mass.Furthermore, the resin particles are preferably (meth)acrylic-modified silicone resin particles.

[0037] Although the (meth)acrylic-modified silicone resin is not particularly limited, it is preferable that the (meth)acrylic-modified silicone resin has a structure represented by the following formula (2). By having the structure represented by the following formula (2), the toner releasability is more likely to be excellent. Furthermore, it is preferable that the (meth)acrylic-modified silicone resin has a structure represented by the following formula (3). By having the structure represented by the following formula (3), the adhesion to the (meth)acrylic rubber and (meth)acrylic resin that may be contained in the surface layer is more likely to be excellent. -Si(R3)(R4)-O- (2) [ka] In formula (2), R3 and R4 each independently represent an alkyl group having 1 to 3 carbon atoms or a hydroxyl group. In formula (3), R5 represents a hydrogen atom or a methyl group, and R6 represents an alkyl group having 1 to 6 carbon atoms. R6 may be linear, branched, or cyclic.

[0038] The structure of the (meth)acrylic-modified silicone resin particles is measured using pyrolysis GC-MS and silicon NMR. Specific measurement methods are described below. The (meth)acrylic-modified silicone resin more preferably has the structure represented by the above formula (2) in the main chain, and more preferably has the structure represented by the above formula (3) in the side chain.

[0039] The proportion of the structure represented by the above formula (2) in the (meth)acrylic-modified silicone resin is preferably 60 to 80 mol %. When the proportion of the structure represented by the above formula (2) is within the above range, the toner tends to have even better releasability. The proportion of the structure represented by the above formula (2) is measured using pyrolysis GC-MS and silicon NMR.

[0040] The proportion of the structure represented by the above formula (3) in the (meth)acrylic-modified silicone resin is preferably 20 to 40 mol %. When the proportion of the structure represented by the above formula (3) is within the above range, the compatibility between the (meth)acrylic portion of the (meth)acrylic-modified silicone resin and the (meth)acrylic rubber and (meth)acrylic resin that may be contained in the surface layer 102 that is in contact with the resin particles becomes better, making it easier to suppress detachment of the resin particles. In addition, the silicone main chain contained in the silicone resin tends to make the toner more releasable. The proportion of the structure represented by the above formula (3) is measured by pyrolysis GC-MS and silicon NMR. The specific measurement method will be described later. The (meth)acrylic-modified silicone resin may be any known resin, and is not particularly limited. Examples of commercially available products include Chaline (registered trademark) R-170S and R-175S (manufactured by Nissin Chemical Industry Co., Ltd.).

[0041] The particle size of the resin particles is not particularly limited, but the number-average particle size is preferably 0.1 to 5 μm, and more preferably 0.5 to 2 μm. If the number-average particle size exceeds the above range, the gaps between the resin particles tend to become large. As a result, the toner release properties may decrease and cleaning problems may occur. Furthermore, if the number-average particle size is smaller than the above range, aggregation may occur between the resin particles, making it difficult to apply the resin to the surface layer. When the particle diameter of the resin particles varies, the particles may be classified using a sieve or the like as necessary to select and use the desired particles.

[0042] When the outer surface of an electrophotographic member is observed with a scanning electron microscope (SEM), and the length in the longitudinal direction perpendicular to the circumferential direction of the electrophotographic member is W, the number of resin particles present in a square observation region of 5 μm length × 5 μm width at any position in a central region of W / 3 from the center in the longitudinal direction of the electrophotographic member toward both ends in the longitudinal direction is preferably 1 to 700, more preferably 1 to 350, even more preferably 1 to 100, particularly preferably 1 to 50, and even more preferably 1 to 30. Here, the circumferential direction of the electrophotographic member includes, for example, the circumferential direction of the electrophotographic member when the electrophotographic member is an electrophotographic belt having an endless shape, and the circumferential direction of the electrophotographic member when the electrophotographic member is cylindrical.

[0043] The absence of any particles in the observation area indicates that the gaps between the resin particles are large. As a result, the toner release property may be reduced or cleaning problems may occur. On the other hand, the presence of more than 700 resin particles in the observation area indicates a state in which aggregation between the resin particles is likely to occur. In other words, it may be difficult to apply a coating material containing resin particles to the surface of the surface layer 102. The number of resin particles present in the observation area can be adjusted by changing the amount of resin particles applied.

[0044] The SEM observation conditions are as follows: SEM: Product name S-4700, manufactured by Hitachi Observation conditions: 10K magnification Accelerating voltage: 2 kV

[0045] When the outer surface of an electrophotographic member is observed with a scanning electron microscope (SEM), and the length in the longitudinal direction perpendicular to the circumferential direction of the electrophotographic member is W, the proportion of the area occupied by resin particles is preferably 50 to 90 area %, more preferably 50 to 80 area %, and even more preferably 50 to 70 area %, based on the area of ​​a 5 μm long x 5 μm wide square observation region at any position in a central region of W / 3 from the center of the electrophotographic member in the longitudinal direction toward both ends in the longitudinal direction, where W is the length of the electrophotographic member. Within this range, good toner releasability is easily achieved. The proportion of the area occupied by the resin particles can be adjusted by changing the amount of resin particles applied, the particle diameter of the resin particles, and the like. The percentage of the area occupied by the resin particles is determined by observing the outer surface of the electrophotographic member at multiple locations in the circumferential direction and calculating the arithmetic average of the obtained area percentages. Specifically, the measurement is performed as follows: the observed image is binarized (e.g., by Otsu's method) using image processing software (e.g., ImageJ), the particle portions are extracted, and the total area of ​​the particle portions is calculated. The total area of ​​the particle portions is divided by the area of ​​the entire observed image, and the result is multiplied by 100 to calculate the percentage of the area occupied by the resin particles.

[0046] (Electrophotographic image forming apparatus) The electrophotographic image forming apparatus of the present disclosure includes an image forming unit including an image carrier, a charging unit, an image exposure unit, and a developing unit; an intermediate transfer member; a primary transfer member that primarily transfers the toner image formed on the image carrier onto the intermediate transfer member; a secondary transfer member that secondarily transfers the toner image on the intermediate transfer member onto a recording material, The developing means includes a toner storage section that stores toner, The intermediate transfer member is the electrophotographic member of the present disclosure, and is an electrophotographic image forming apparatus.

[0047] An example of an electrophotographic image forming apparatus using the electrophotographic member of the present disclosure will be described with reference to Fig. 2. However, the present disclosure is not limited to the following description.

[0048] The electrophotographic image forming apparatus 100 in FIG. 2 is a color electrophotographic image forming apparatus (color laser printer). This electrophotographic image forming apparatus is equipped with an electrophotographic belt (electrophotographic member) 7, which serves as an intermediate transfer member. That is, the intermediate transfer member is preferably the electrophotographic member of the present disclosure. The electrophotographic member is preferably an endless electrophotographic belt. Further, image forming units Py, Pm, Pc, and Pk of yellow (Y), magenta (M), cyan (C), and black (K) are disposed along a flat portion of the electrophotographic belt 7 in the moving direction of the belt. In FIG. 2, 1Y, 1M, 1C, and 1K respectively represent electrophotographic photosensitive members, and 2Y, 2M, 2C, and 2K respectively represent charging rollers. Also, 3Y, 3M, 3C, and 3K respectively represent laser exposure devices, 4Y, 4M, 4C, and 4K respectively represent developing devices, and 5Y, 5M, 5C, and 5K respectively represent primary transfer rollers. Since the basic configuration of each image forming unit is the same, the details of the image forming units will be explained only for the yellow image forming unit Py.

[0049] The yellow image forming unit Py has a drum-shaped electrophotographic photosensitive member 1Y (hereinafter also referred to as "photosensitive drum" or "first image carrier") as an image carrier. The photosensitive drum 1Y is formed by laminating a charge generation layer, a charge transport layer, and a surface protection layer in this order on an aluminum cylinder as a base. The yellow image forming unit Py also includes a charging roller 2Y as a charging means. By applying a charging bias to the charging roller 2Y, the surface of the photosensitive drum 1Y is uniformly charged.

[0050] A laser exposure device 3Y is disposed above the photosensitive drum 1Y as an image exposure means. The laser exposure device 3Y scans and exposes the uniformly charged surface of the photosensitive drum 1Y in accordance with image information, forming an electrostatic latent image of a yellow color component on the surface of the photosensitive drum 1Y. The electrostatic latent image formed on the photosensitive drum 1Y is developed with toner, which is a developer, by a developing device 4Y as a developing means. That is, the developing means is provided with a toner storage section that stores toner. The developing device 4Y is provided with a developing roller 4Ya, which is a developer carrier, and a regulating blade 4Yb, which is a developer amount regulating member, and stores yellow toner, which is a developer. The developing roller 4Ya, to which yellow toner is supplied, develops the electrostatic latent image on the photosensitive drum 1Y in the developing section. The developing roller 4Ya is in light pressure contact with the photosensitive drum 1Y and rotates in the forward direction with a speed difference from the photosensitive drum 1Y. The yellow toner transported to the developing section by the developing roller 4Ya adheres to the electrostatic latent image formed on the photosensitive drum 1Y by applying a developing bias to the developing roller 4Ya. As a result, a visible image (yellow toner image) is formed on the photosensitive drum 1Y.

[0051] The electrophotographic belt 7 is stretched around a drive roller 71, a tension roller 72, and a driven roller 73, and is moved (rotationally driven) in the direction of the arrow in the figure while in contact with the photosensitive drum 1Y. The yellow toner image formed on the photosensitive drum (first image carrier) that has reached the primary transfer portion Ty is primarily transferred onto the electrophotographic belt 7 by a primary transfer member (primary transfer roller 5Y) that is arranged opposite the photosensitive drum 1Y via the electrophotographic belt 7. That is, the electrophotographic image forming apparatus includes a primary transfer member that primarily transfers the toner image formed on the image carrier onto the intermediate transfer member. Similarly, the above image forming operation is performed in each of the magenta (M), cyan (C), and black (K) units Pm, Pc, and Pk as the electrophotographic belt 7 moves, resulting in four-color toner images of yellow (Y), magenta (M), cyan (C), and black (K) being stacked on the electrophotographic belt 7. The four-color toner images are transported along the electrophotographic belt 7 and transferred together at a predetermined timing at the secondary transfer section T' by a secondary transfer member (secondary transfer roller 8) onto a recording material S (hereinafter also referred to as a "second image carrier") being transported thereto. That is, the electrophotographic image forming apparatus includes a secondary transfer member that performs a second transfer of the toner image on the intermediate transfer member to the recording material. In this secondary transfer, a transfer voltage of several kV is typically applied to ensure a sufficient transfer rate.

[0052] The recording material S is supplied to a conveying path from a cassette 12 storing the recording material S by a pickup roller 13. The recording material S supplied to the conveying path is conveyed to a secondary transfer portion T' in synchronization with the four-color toner image transferred to the electrophotographic belt 7 by a conveying roller pair 14 and a registration roller pair 15. The toner image transferred to the recording material S is fixed by a fixing device 9 to become, for example, a full-color image. The fixing device 9 has a fixing roller 91 equipped with a heating means and a pressure roller 92, and fixes the unfixed toner image on the recording material S by applying heat and pressure. Thereafter, the recording material S is discharged to the outside of the apparatus by a pair of conveying rollers 16, a pair of discharging rollers 17, etc.

[0053] A cleaning unit for the electrophotographic belt 7 is disposed downstream of the secondary transfer portion T' in the driving direction of the electrophotographic belt 7, and removes the residual toner remaining on the electrophotographic belt 7 without being transferred to the recording material S at the secondary transfer portion T'.

[0054] As described above, the process of electrically transferring a toner image from the photoreceptor to the electrophotographic belt and from the electrophotographic belt to the recording material is repeated. Furthermore, by repeatedly recording on a large number of recording materials, the electrical transfer process is further repeated.

[0055] (Toner and Developer) The toner used in the electrophotographic image forming apparatus is not particularly limited, but it is preferable that the toner contains toner particles, and the toner particles contain a polyester resin having a polyethylene terephthalate segment. The toner will be described below.

[0056] <Polyester resin containing polyethylene terephthalate segments> The polyester resin has a polyethylene terephthalate segment and can be obtained by selecting and combining suitable monomers from among divalent or higher alcohol monomers, divalent or higher carboxylic acids, divalent or higher carboxylic acid anhydrides, and divalent or higher carboxylic acid esters, and synthesizing the monomers using a known method.

[0057] <Polyethylene terephthalate segment> The polyethylene terephthalate segment is a structural unit of polyethylene terephthalate, C 10 It has a structure in which H8O4 is repeated. The polyethylene terephthalate segment can be obtained by producing a polyester resin according to a known method, such as by a condensation reaction or transesterification reaction between ethylene glycol and terephthalic acid, dimethyl terephthalate, etc. Alternatively, the polyethylene terephthalate segment can be obtained by synthesizing a polyester resin using recovered polyethylene terephthalate resin as a monomer.

[0058] Polyethylene terephthalate resin is used in various products such as containers and films, and from the viewpoint of environmental protection, it is preferable to recover and reuse it. That is, recovered polyethylene terephthalate resin refers to recycled polyethylene terephthalate resin. The type of recovered polyethylene terephthalate resin is not particularly limited, but it is preferable that it does not contain impurities that may affect the toner properties or reactions in the manufacturing process, and more preferably has an appropriate purity.

[0059] <Dihydric or higher alcohol monomer component> The dihydric or higher alcohol monomer component is not particularly limited, but examples thereof include alkylene oxide adducts of bisphenol A such as polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene(3.3)-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene(2.0)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene(2.0)-polyoxyethylene(2.0)-2,2-bis(4-hydroxyphenyl)propane, and polyoxypropylene(6)-2,2-bis(4-hydroxyphenyl)propane; ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, neopentyl glycol, polyethylene glycol, and polypropylene glycol. These may be used alone or in combination. Among these, alkylene oxide adducts of bisphenol A are preferred.

[0060] <Acid monomer component> The acid monomer components such as divalent or higher carboxylic acids, divalent or higher carboxylic acid anhydrides, and divalent or higher carboxylic acid esters are not particularly limited, but include aromatic dicarboxylic acids or their anhydrides such as phthalic acid, isophthalic acid, and terephthalic acid; alkyl dicarboxylic acids or their anhydrides such as oxalic acid, malonic acid, succinic acid, adipic acid, maleic acid, fumaric acid, citraconic acid, and itaconic acid. These can be used alone or in combination. Among them, fumaric acid is preferred.

[0061] <Method for producing polyester resin having polyethylene terephthalate segments> The polyester resin having a polyethylene terephthalate segment can be produced by a conventional polyester synthesis method, except that the polyethylene terephthalate segment is obtained by the method described above. For example, a desired polyester resin can be obtained by esterifying or transesterifying a carboxylic acid monomer with an alcohol monomer, followed by polycondensation under reduced pressure or by introducing nitrogen gas according to a known method.

[0062] <Release agent> The toner particles may contain a release agent, which preferably contains a wax. Examples of waxes include polyolefin waxes such as polyethylene wax, polypropylene wax, and polypropylene copolymer wax, petroleum waxes such as microcrystalline wax and paraffin wax, Fischer-Tropsch wax, and the like. Examples of waxes that can be used include hydrocarbon waxes such as cellulose acetate, natural waxes such as carnauba wax, rice wax, and candelilla wax, and montan wax. These waxes may also be derivatives. These waxes can be used alone or in combination. The content of the release agent in the toner particles is not particularly limited, but may be 1 to 5% by mass.

[0063] <Coloring agent> The toner particles may include a colorant. Examples of colorants include known organic pigments, oil-based dyes, magnetic materials, etc. Examples of colorants include carbon black, phthalocyanine blue, permanent brown FG, brilliant fast scarlet, pigment red 122, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, isoindoline, disazo yellow, benzidine yellow, monoazo dyes and pigments, and disazo dyes and pigments. The content of the colorant in the toner particles is not particularly limited, but may be 2 to 8% by mass.

[0064] <Charge control agent> The toner particles may optionally contain a charge control agent. Known charge control agents can be used, including positive charge control agents and negative charge control agents. Positive charge control agents include quaternary ammonium salt compounds, triphenylmethane compounds, imidazole compounds, and nigrosine dyes. Negative charge control agents include benzilic acid metal compounds, salicylic acid metal compounds, copper phthalocyanine dyes, and quaternary ammonium salt compounds. Of these, negative charge control agents are preferred. The content of the charge control agent in the toner particles is not particularly limited, but may be 0.1 to 2% by mass.

[0065] <Developer> The toner can be used as a one-component developer, but in order to further improve dot reproducibility and to provide stable images over a long period of time, it is preferable to mix the toner with a magnetic carrier and use it as a two-component developer. As the magnetic carrier, for example, metal particles such as iron, cobalt, and nickel, and magnetic materials such as ferrite, and other commonly known magnetic carriers can be used. [Example]

[0066] The present disclosure will be specifically described below using examples. However, the present disclosure is not limited to the following examples. Note that the number of parts in the following formulations is always by mass unless otherwise specified.

[0067] [Example 1] (Electrophotographic belt manufacturing) (Formation of the base layer) Conductive carbon black (trade name: Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.) was added to an N-methyl-2-pyrrolidone solution of polyamic acid, a polyimide precursor (trade name: U Varnish A, manufactured by Ube Industries, Ltd.) and mixed so that the conductive carbon black accounted for 19% by mass of the total mass of the polyamic acid and the conductive carbon black. The obtained mixture was applied to the outer peripheral surface of a cylindrical support made of stainless steel (SUS304) whose surface had been subjected to blast treatment. Then, the cylindrical support was heated in a heating furnace at a temperature of 220°C for 3 hours. The cylindrical support was heated for 10 minutes, and then heated at 350°C for 30 minutes. This polymerized the polyimide precursor coated on the outer peripheral surface of the cylindrical support, forming a polyimide film. After cooling, the polyimide film was removed from the cylindrical support, yielding a base layer in the shape of an endless belt with a thickness of 70 µm.

[0068] Next, the outer surface of the obtained base layer was irradiated with excimer UV to perform a hydrophilic treatment, and then a primer liquid (product name: DY39-051A / B, manufactured by Dow-Toray Industries, Inc.) was applied to the outer surface of the base layer, and the base layer was placed in a heating furnace and heated at 160°C for 10 minutes.

[0069] (Formation of surface layer) After the base layer was sufficiently cooled, an elastic layer was formed on the base layer as a surface layer by the following procedure. The constituent materials shown below were kneaded using a twin-screw kneader (trade name: PCM30, manufactured by Ikegai Corporation) to obtain pellets.

[0070] Acrylic rubber (trade name: Nipol AR12, manufactured by Zeon Corporation) 100 parts by mass (6-aminohexyl)carbamic acid (trade name: Diak No. 1, manufactured by Chemours) 0.6 parts by mass 1,3-di-o-tolylguanidine (trade name: Noccela DT, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) 1 part by mass 1 part by mass of stearic acid (product name: Beads Stearic Acid, manufactured by NOF Corporation) 0.2 parts by mass of potassium bis(trifluoromethanesulfonyl)imide potassium (product name: EF-N112, manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.)

[0071] The obtained pellets were dissolved in methyl isobutyl ketone (MIBK) as a solvent to prepare a coating liquid for the elastic layer. The previously prepared base layer was attached to a cylindrical core, and a ring nozzle for discharging rubber was attached coaxially with the core. The coating liquid for the elastic layer was supplied to the ring nozzle using a liquid feed pump and discharged through a slit, thereby coating the coating liquid for the elastic layer onto the base layer. The amount of liquid applied was set so that the final film thickness would be 500 μm.

[0072] (Installation of resin particles on the outer surface of the surface layer) Next, resin particles were applied to the outer surface of the applied coating liquid. The resin particles used were classified acrylic-modified silicone resin particles (Resin Particles A, product name: Chaline R-170S, manufactured by Nissin Chemical Industry Co., Ltd.) (number average particle diameter: 1 μm). Specifically, the resin particles were applied by the following procedure. The surface of the coating liquid applied to the previously prepared base layer was evenly coated with acrylic-modified silicone resin particles, and the surface was smoothed with a pressing member to remove excess particles. The base layer containing the coating liquid and the particles on the surface of the coating liquid was then placed on a cylindrical support and heated to 160°C in a heating furnace at a heating rate of 5°C / min and held there for 60 minutes. The base layer was then cooled to room temperature and demolded to obtain an electrophotographic belt. At least a portion of the resin particles were in direct contact with the outer surface of the surface layer, and a portion of the outer surface of the electrophotographic belt was composed of resin particles.

[0073] When the surface of the produced electrophotographic belt was observed with a scanning electron microscope (SEM) using the method described above, the number of resin particles present in a 5 μm × 5 μm square observation area was found to be 21. Furthermore, based on the area of ​​the square observation area, the area occupied by the resin particles was 65%.

[0074] The structures of the (meth)acrylic unit and silicone unit of the (meth)acrylic-modified silicone resin particles used were identified using pyrolysis GC-MS (Agilent). The MS conditions were as follows: Apparatus: 6890N (Agilent Technologies) Accessory equipment: Multi-shot pyrolyzer PY3030D (Frontier Labs) Pyrolysis temperature: 600℃ In addition, the (meth)acrylic-modified silicone resin particles were dissolved in a heavy solvent (heavy chloroform) and silicon NMR measurement was performed to measure the molar ratio of the structure bonded to silicon atoms. Specifically, the ratio of the silicon portion bonded to the (meth)acrylic group relative to the total silicon contained in the (meth)acrylic-modified silicone resin particles was calculated, and this was taken as the ratio of the structure represented by the above formula (3). The ratio of the structure represented by the above formula (3) in the particles according to this example was 30 mol%.

[0075] (developer production) In this example, the following developer was used. [Production of Resin 1] A reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube was charged with 100 parts of a propylene oxide adduct of bisphenol A (average number of moles added: 2.2 moles), 21 parts of recovered polyethylene terephthalate (diethylene glycol content = 1.3% by mass), and 0.08 parts of dibutyltin oxide under a nitrogen atmosphere. The reaction vessel was heated to 230 ° C while stirring at 200 rpm and reacted for 7 hours. The mixture was then cooled to 180 ° C, and 30 parts of fumaric acid and 0.08 parts of hydroquinone were added and heated to 210 ° C over 4 hours. The pressure was then reduced to 8 kPa and the reaction was continued until the softening point reached 103 ° C, yielding Resin 1.

[0076] [Production of Resin 2] A reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube was charged with 100 parts of a propylene oxide adduct of bisphenol A (average number of moles added: 2.2 moles), 40 parts of an ethylene oxide adduct of bisphenol A (average number of moles added: 2.2 moles), 13 parts of dodecenyl succinic anhydride, 37 parts of terephthalic acid, 12 parts of trimellitic anhydride, and 0.5 parts of dibutyltin oxide under a nitrogen atmosphere. The reaction vessel was heated to 235 ° C. while stirring at 200 rpm, and the reaction was carried out for 4 hours. The pressure was then reduced to 8 kPa and the reaction was continued until the softening point reached 146 ° C., yielding Resin 2.

[0077] [Production of toner particles 1] Resin 1 70 parts Resin 2 30 parts Colorant ECB-301 (manufactured by Dainichiseika Chemicals Co., Ltd., CI Pigment Blue 15:3) 5 parts Charge control agent LR-147 (manufactured by Nippon Carlit Co., Ltd.) 1 part Release agent NP-105 (manufactured by Mitsui Chemicals, Inc., melting point: 140°C) 4 parts The above materials were mixed in a Henschel mixer (FM-75 model, manufactured by Nippon Coke & Engineering Co., Ltd.) at a rotation speed of 20 s -1 The mixture was mixed for 5 minutes with a rotation time of 5 minutes. The mixture was then kneaded at a discharge temperature of 135°C in a twin-screw kneader (PCM-30, manufactured by Ikegai Corporation) set at a temperature of 120°C and a screw rotation speed of 200 rpm. The resulting kneaded mixture was cooled at a cooling rate of 15°C / min and roughly pulverized to 1 mm or less using a hammer mill to obtain a coarsely pulverized product. The resulting coarsely pulverized product was finely pulverized using a mechanical pulverizer (T-250, manufactured by Freund Turbo Corporation). It was then classified using a Faculty F-300 (manufactured by Hosokawa Micron Corporation) to obtain toner particles 1. The operating conditions for classification were a classifying rotor rotation speed of 130 s -1 , distributed rotor rotation speed 120s -1 It was decided.

[0078] [Production of Toner 1] The following materials were mixed in a Henschel mixer FM-10C (manufactured by Mitsui Miike Chemical Engineering) at a rotation speed of 30 s. -1 The mixture was mixed for 10 minutes, and a toner 1 was obtained. 100 parts of toner particles External additive 1: Aerosil R-972 (manufactured by Nippon Aerosil Co., Ltd., average particle size 16 nm) 1.0 copies External additive 2 SI-Y (manufactured by Nippon Aerosil Co., Ltd., average particle size 40 nm) 1.0 part

[0079] (Magnetic carrier manufacturing example) Number average particle size: 0.30 μm, magnetization strength: 65 Am under a magnetic field of 1000 / 4π (kA / m) 2 / kg) of magnetite 1 Number average particle size: 0.50 μm, magnetization strength: 65 Am under a magnetic field of 1000 / 4π (kA / m) 2 / kg) of magnetite2 To 100 parts of each of the above materials, 4.0 parts of a silane compound (3-(2-aminoethylaminopropyl)trimethoxysilane) was added, and the mixture was mixed and stirred at high speed in a container at 100° C. or higher to treat each of the fine particles.

[0080] Phenol: 10% by weight Formaldehyde solution: 6% by mass (Formaldehyde 40% by mass, methanol 10% by mass, water 50% by mass) Magnetite treated with the above silane compound 1: 58 mass% Magnetite 2 treated with the above silane compound: 26% by mass 100 parts of the above material, 5 parts of 28% by mass aqueous ammonia solution, and 20 parts of water were placed in a flask, and the temperature was raised to 85°C over 30 minutes while stirring and mixing. After the temperature was raised, the mixture was maintained for 3 hours to carry out a polymerization reaction, and the resulting phenolic resin was cured. The cured phenolic resin was then cooled to 30°C, and water was added. The supernatant was then removed, and the precipitate was washed with water and air-dried. The air-dried product was then dried at 60°C under reduced pressure (5 mmHg or less) to obtain spherical magnetic carrier 1 with dispersed magnetic material. The volume-based 50% particle size (D50) of magnetic carrier 1 was 34 μm.

[0081] [Example of manufacturing developer 1] The following materials were mixed in a V-type mixer (V-20, manufactured by Seishin Enterprises) to obtain Developer 1: 8 parts of Toner 1 Magnetic carrier 1 92 parts

[0082] [Example 2] In Example 2, an electrophotographic belt was produced in the same manner as in Example 1, except that the surface layer in Example 1 was changed to a resin layer (acrylic resin). Specifically, the resin layer was formed in the following manner.

[0083] (Preparation of resin layer) Intermediate (H) was prepared by mixing the following materials with a homogenizer. Methyl ethyl ketone (Kishida Chemical Co., Ltd.) 26.9 parts by mass Butyl acetate (Kishida Chemical Co., Ltd.) 26.9 parts by mass Aronix M405 (manufactured by Toagosei Co., Ltd.) 42.0 parts by weight Irgacure 184 (BASF) 2.9 parts by weight Irgacure 369 (BASF) 1.1 parts by weight

[0084] A conductive agent was added to the intermediate (H) in the following proportions, and the mixture was stirred using a mix rotor to prepare a coating material (I). ·Intermediate (H) 79 parts by mass 3 parts by weight of Celnax CX-Z410K (Nissan Chemical Co., Ltd.) Celnax CX-Z210IP (Nissan Chemical Co., Ltd.) 6 parts by weight Isopropyl alcohol (Kishida Chemical Co., Ltd.) 12 parts by weight

[0085] The outer surface of the base layer prepared in the same manner as in Example 1 was treated with a corona treatment device (manufactured by Kasuga Electric Co., Ltd.) at a discharge rate of 100 W·min / m 2 Corona treatment was performed under the conditions (adhesion-enhancing treatment). Thereafter, paint (I) was spray-coated onto the outer peripheral surface of the base layer. Then, resin particles A similar to those in Example 1 were applied to the outer surface of the spray-coated paint (I) in the same manner as in Example 1. The solvent was evaporated in a drying oven at 70°C for 1 minute, and a curing reaction was carried out by the effect of UV. The thickness of the resulting resin layer was 8 μm.

[0086] When the surface of the produced electrophotographic belt was observed with a scanning electron microscope (SEM) using the method described above, the number of resin particles present in a 5 μm × 5 μm square observation area was found to be 20. Furthermore, based on the area of ​​the square observation area, the area occupied by the resin particles was 63%.

[0087] [Example 3] In Example 3, an electrophotographic belt was produced in the same manner as in Example 2, except that TMPT (manufactured by Shin-Nakamura Chemical Co., Ltd.) was used instead of Aronix M405 in Example 2. The thickness of the obtained resin layer was 8 μm.

[0088] When the surface of the produced electrophotographic belt was observed with a scanning electron microscope (SEM) using the method described above, the number of resin particles present in a 5 μm × 5 μm square observation area was found to be 20. Furthermore, based on the area of ​​the square observation area, the area occupied by the resin particles was 63%.

[0089] [Comparative Example 1] In Comparative Example 1, an electrophotographic belt was produced in the same manner as in Example 1, except that the resin particles A in Example 1 were changed to the following resin particles B. ·Acrylic resin particles (resin particles B, product name: TECHPOLYMER SSX-101, manufactured by Sekisui Plastics Co., Ltd.)

[0090] Comparative Example 2 In Comparative Example 1, an electrophotographic belt was produced in the same manner as in Example 1, except that the resin particles A in Example 1 were changed to the following resin particles C. Silicone resin particles (product name: Tospearl 120, manufactured by Momentive Performance Materials)

[0091] (Calculation of elastic deformation power ηIT) Using the produced electrophotographic belt, a nanoindentation test of the elastic layer based on the above-mentioned ISO14577 was carried out, and the elastic deformation power ηIT was calculated from the measurement results of the load-displacement curve.

[0092] (Evaluation of image density uniformity) The evaluation of image density uniformity was carried out by mounting the electrophotographic belt as an intermediate transfer belt in a full-color electrophotographic forming apparatus (trade name: imagePRESS C800, manufactured by Canon Inc.). The test was performed on an A3-sized embossed paper (product name: Lezac 66 250g / m) at a temperature of 25°C and a relative humidity of 55%. 2 Solid images of secondary colors of cyan and magenta were formed on a sheet of paper (manufactured by Tokushu Tokai Seishi Co., Ltd.) and evaluated according to the following criteria. Rank A: No image unevenness is observed and it is good. Rank B: Slight image unevenness in some of the recessed areas of the embossed paper Rank C: Clear image unevenness in less than 50% of the embossed paper recesses Rank D: Clear image unevenness in more than 50% of the embossed paper recesses

[0093] (Evaluation of image density uniformity after durability test) Using the electrophotographic forming apparatus described above, images were output continuously on 100,000 sheets (test chart) of A3-size plain paper (product name: CS068, manufactured by Canon Inc.) in an environment of 25°C temperature and 55% relative humidity. After that, images were output on 100,000 sheets (test chart) of A3-size embossed paper (product name: Lezac 66 250 g / m 2 Solid images of secondary colors of cyan and magenta were formed on the entire surface of a sheet of paper (manufactured by Tokushu Tokai Seishi Co., Ltd.), and evaluated according to the same criteria as in the evaluation of image density uniformity described above.

[0094] (Evaluation results) Table 1 shows the evaluation results of the electrophotographic belts produced in Examples 1 to 3 and Comparative Examples 1 and 2. In Example 1, both the image density uniformity and the image density uniformity after durability testing were good results. In Examples 2 and 3, slight image unevenness was observed in the image density uniformity, but it was within the acceptable range, and the same results were obtained after the durability test. Note that, since Examples 2 and 3 did not have an elastic layer, the elastic deformation power was not measured. In Comparative Example 1, clear image unevenness was observed. This is thought to be because the resin particles were acrylic resin particles, which reduced the toner's releasability and transferability compared to acrylic-modified silicone resin particles. On the other hand, no deterioration in image quality was observed after durability testing. This is thought to be due to the high compatibility between the acrylic resin particles and the acrylic rubber. In Comparative Example 2, the image density uniformity was good, but after the durability test, the image density uniformity decreased. When the surface of the electrophotographic belt was observed with a scanning electron microscope (SEM), detachment of resin particles was observed. Because the wood particles were silicone resin particles, they were poorly compatible with the acrylic rubber, which is thought to have caused the detachment during the paper feed durability test. [Table 1]

[0095] The present disclosure includes the following configurations. (Configuration 1) 1. An electrophotographic member having a base layer and a surface layer on the base layer, the surface layer contains at least one selected from the group consisting of a (meth)acrylic resin and a (meth)acrylic rubber, a plurality of resin particles are present on the outer surface of the surface layer, at least some of the plurality of resin particles are in direct contact with the outer surface of the surface layer; a part of an outer surface of the electrophotographic member is made of the resin particles, and the outer surface of the electrophotographic member has irregularities formed by the resin particles; The resin particles contain a (meth)acrylic-modified silicone resin. Electrophotographic member characterized by: (Configuration 2) 2. The electrophotographic printer according to claim 1, wherein the surface layer is an elastic layer containing the (meth)acrylic rubber. True part. (Configuration 3) The electrophotographic member according to Configuration 2, wherein, when a load-displacement curve is obtained by a nanoindentation test of the elastic layer based on ISO 14577 in which a Vickers indenter is brought into contact with an outer surface of the elastic layer and a test load of 120 μN is set, the elastic deformation power ηIT calculated from the load-displacement curve is 60 to 90%. (Configuration 4) The electrophotographic member according to Configuration 2 or 3, wherein the (meth)acrylic rubber has a structure represented by the following formula (1): TIFF2025162519000006.tif41170 In formula (1), R1 represents a methyl group or a hydrogen atom, and R2 represents an alkyl group having 1 to 18 carbon atoms or an alkyl group having 2 to 18 carbon atoms and an ether bond. (Configuration 5) 2. The electrophotographic member according to Configuration 1, wherein the surface layer is a resin layer containing the (meth)acrylic resin. (Configuration 6) The electrophotographic member according to Configuration 5, wherein the (meth)acrylic resin has a structure represented by the following formula (1′): TIFF2025162519000007.tif42170 In formula (1'), R7 represents a methyl group or a hydrogen atom, and R8 represents an alkyl group having 1 to 18 carbon atoms or an alkyl group having 2 to 18 carbon atoms and an ether bond. (Configuration 7) The electrophotographic member according to any one of configurations 1 to 6, wherein the (meth)acrylic-modified silicone resin has a structure represented by the following formula (2) and a structure represented by the following formula (3): -Si(R3)(R4)-O- (2) TIFF2025162519000008.tif45170In formula (2), R3 and R4 each independently represent an alkyl group having 1 to 3 carbon atoms or a hydroxyl group, and in formula (3), R5 represents a hydrogen atom or a methyl group, and R6 represents an alkyl group having 1 to 6 carbon atoms. (Configuration 8) 8. The electrophotographic member according to claim 7, wherein the proportion of the structure represented by the formula (3) in the (meth)acrylic-modified silicone resin is 20 to 40%. (Configuration 9) 9. The electrophotographic member according to any one of configurations 1 to 8, wherein the electrophotographic member is an electrophotographic belt having an endless shape. (Configuration 10) The electrophotographic member according to Configuration 9, wherein, when the outer surface of the electrophotographic member is observed with a scanning electron microscope, the number of resin particles present in a square observation area of ​​5 μm long x 5 μm wide at any position in a central region of W / 3 from the center in the longitudinal direction of the electrophotographic member toward both ends in the longitudinal direction, where W is the length in the longitudinal direction perpendicular to the circumferential direction of the electrophotographic member, is 1 to 700. (Configuration 11) The electrophotographic member according to Configuration 9 or 10, wherein, when the outer surface of the electrophotographic member is observed with a scanning electron microscope, and the length of the electrophotographic member in a longitudinal direction perpendicular to a circumferential direction is W, the proportion of the area occupied by the resin particles is 50 to 90 area % based on the area of ​​a square observation region of 5 μm length × 5 μm width at an arbitrary position in a central region of W / 3 from the center of the electrophotographic member in the longitudinal direction toward both ends in the longitudinal direction. (Configuration 12) an image forming unit including an image carrier, a charging means, an image exposure means, and a developing means; an intermediate transfer member; a primary transfer member that primarily transfers the toner image formed on the image carrier onto the intermediate transfer member; a secondary transfer member that secondarily transfers the toner image on the intermediate transfer member onto a recording material, The developing means includes a toner storage section that stores toner, 12. An electrophotographic image forming apparatus, wherein the intermediate transfer member is the electrophotographic member according to any one of Configurations 1 to 11. (Configuration 13) the toner comprises toner particles; 13. An electrophotographic imaging apparatus according to claim 12, wherein the toner particles contain a polyester resin having polyethylene terephthalate segments. [Explanation of symbols]

[0096] 1 electrophotographic photosensitive member (photosensitive drum), 2 charging roller, 3 laser exposure device, 4 developing device, 5 primary transfer roller, 7 electrophotographic belt, 8 secondary transfer roller, 9 fixing device, 101 base layer, 102 surface layer, 103 resin particles

Claims

1. 1. An electrophotographic member having a base layer and a surface layer on the base layer, the surface layer contains at least one selected from the group consisting of a (meth)acrylic resin and a (meth)acrylic rubber, a plurality of resin particles are present on the outer surface of the surface layer, at least some of the plurality of resin particles are in direct contact with the outer surface of the surface layer; a part of an outer surface of the electrophotographic member is made of the resin particles, and the outer surface of the electrophotographic member has irregularities formed by the resin particles; The resin particles contain a (meth)acrylic-modified silicone resin. Electrophotographic member characterized by:

2. 2. The electrophotographic member according to claim 1, wherein the surface layer is an elastic layer containing the (meth)acrylic rubber.

3. 3. The electrophotographic member according to claim 2, wherein, when a load-displacement curve is obtained by a nanoindentation test of the elastic layer based on ISO 14577 in which a Vickers indenter is brought into contact with an outer surface of the elastic layer and a test load of 120 μN is set, the elastic deformation power ηIT calculated from the load-displacement curve is 60 to 90%.

4. 3. The electrophotographic member according to claim 2, wherein the (meth)acrylic rubber has a structure represented by the following formula (1): In formula (1), R1 represents a methyl group or a hydrogen atom, and R2 represents an alkyl group having 1 to 18 carbon atoms or an alkyl group having 2 to 18 carbon atoms and an ether bond.

5. 2. The electrophotographic member according to claim 1, wherein the surface layer is a resin layer containing the (meth)acrylic resin.

6. The electrophotographic member according to claim 5, wherein the (meth)acrylic resin has a structure represented by the following formula (1'): In formula (1'), R7 represents a methyl group or a hydrogen atom, and R8 represents an alkyl group having 1 to 18 carbon atoms or an alkyl group having 2 to 18 carbon atoms and an ether bond.

7. 2. The electrophotographic member according to claim 1, wherein the (meth)acrylic-modified silicone resin has a structure represented by the following formula (2) and a structure represented by the following formula (3): -Si(R3)(R4)-O- (2) In formula (2), R3 and R4 each independently represent an alkyl group having 1 to 3 carbon atoms or a hydroxyl group, and in formula (3), R5 represents a hydrogen atom or a methyl group, and R6 represents an alkyl group having 1 to 6 carbon atoms.

8. 8. The electrophotographic member according to claim 7, wherein the ratio of the structure represented by formula (3) in the (meth)acrylic-modified silicone resin is 20 to 40%.

9. 2. The electrophotographic member of claim 1, wherein said electrophotographic member is an electrophotographic belt having an endless configuration.

10. The electrophotographic member according to claim 9, wherein the outer surface of the electrophotographic member is observed with a scanning electron microscope, and when the length in a longitudinal direction perpendicular to a circumferential direction of the electrophotographic member is W, the number of the resin particles present in a square observation region of 5 μm length×5 μm width at any position in a central region of W / 3 from the center in the longitudinal direction of the electrophotographic member toward both ends in the longitudinal direction is 1 to 700.

11. The electrophotographic member according to claim 9, wherein the outer surface of the electrophotographic member is observed with a scanning electron microscope, and when the length in a longitudinal direction perpendicular to a circumferential direction of the electrophotographic member is W, a proportion of an area occupied by the resin particles is 50 to 90 area % based on an area of ​​a square observation region of 5 μm length×5 μm width at an arbitrary position in a central region of W / 3 from the center in the longitudinal direction of the electrophotographic member toward both ends in the longitudinal direction.

12. an image forming unit including an image carrier, a charging means, an image exposure means, and a developing means; an intermediate transfer member; a primary transfer member for primarily transferring the toner image formed on the image carrier onto the intermediate transfer member; a secondary transfer member that secondarily transfers the toner image on the intermediate transfer member onto a recording material, The developing means includes a toner storage section that stores toner, 12. An electrophotographic image forming apparatus, wherein the intermediate transfer member is the electrophotographic member according to claim 1.

13. the toner comprises toner particles; 13. The electrophotographic imaging apparatus of claim 12, wherein the toner particles comprise a polyester resin having polyethylene terephthalate segments.

Images