Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

Abstract

The present application relates to an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus. An electrophotographic photosensitive member in which surface direction unevenness of an output image can be suppressed during the entire repeated image formation is provided. The electrophotographic photosensitive member is an electrophotographic photosensitive member including a support having a cylindrical shape, and a photosensitive layer formed on the support, wherein the support contains at least one of aluminum or an aluminum alloy, and wherein when an area at a time of a maximum frequency calculated from an area distribution curve of aluminum crystal grains of a surface of the support is represented by A (μm 2 ), and a half value width of a maximum peak in the area distribution curve is represented by B (μm 2 ), the support satisfies the following formula (1): B / A ≤ 1.0 … (1).

Description

TECHNICAL FIELD

[0001] The present application relates to an electrophotographic photosensitive member, and to a process cartridge and an electrophotographic apparatus each including the electrophotographic photosensitive member. BACKGROUND

[0002] In recent years, diversification of users of electrophotographic apparatuses is progressing, and thus there is an increasing demand for outputting images having higher quality than conventional images. In International Publication No. WO 2019 / 077705, as a technique relating to improvement of image quality, a technique including setting a stress value of a conductive support to a range of -30 MPa or more and 5 MPa or less is described. In Japanese Patent Application Laid-Open No. 2009-150958, as a technique for improving image quality from the viewpoint of precision, a technique including heating an aluminum alloy pipe blank at 190°C to 550°C before cutting processing is described. Further, in Japanese Patent Application Laid-Open No. 2017-111409, a technique including setting an average area of crystal grains of an aluminum alloy having a specific composition to 3 pm 2 or more and 100 pm or less is described. The following technique is described. 2 SUMMARY

[0003] According to the research of the inventor of the present application, the electrophotographic photosensitive member described in International Publication No. WO 2019 / 077705, Japanese Patent Application Laid-Open No. 2009-150958, or Japanese Patent Application Laid-Open No. 2017-111409 involves a problem in that surface direction unevenness easily occurs in an output image when image formation is repeatedly performed. Therefore, an object of the present application is to provide an electrophotographic photosensitive member that can suppress surface direction unevenness of an output image during the entire repeated image formation.

[0004] The object is achieved by the present application described below. That is, the electrophotographic photosensitive member according to the present application is an electrophotographic photosensitive member including: a support having a cylindrical shape; and a photosensitive layer formed on the support, wherein the support contains at least one of aluminum or an aluminum alloy, and wherein when an area at a time of a maximum frequency calculated from an area distribution curve of aluminum crystal grains of a surface of the support is represented by A (pm 2 ) and a half-value width of a maximum peak in the area distribution curve is represented by B (pm 2 ), the support satisfies the following formula (1).

[0005] B / A ≤ 1.0 … (1)

[0006] An electrophotographic photosensitive member that can suppress surface direction unevenness of an output image during the entire repeated image formation can be provided.

[0007] ​Further features of the present application will become apparent from the following description of exemplary embodiments with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1A is a schematic view of an observation screen when a support surface of an electrophotographic photosensitive member of the present application is observed with an electron microscope.

[0009] Figure 1B is a graph showing an area distribution of crystal grains.

[0010] Figure 2 is a view illustrating an example of a schematic configuration of an electrophotographic apparatus of the present application. DETAILED DESCRIPTION

[0011] The present application will be described in detail below by way of exemplary embodiments.

[0012] The inventors of the present application conducted research, and as a result, found that in an electrophotographic photosensitive member of the related art, when image formation is repeatedly performed, slight deviation of potential at an exposed portion of the photosensitive member occurs due to slight resistance unevenness of the conductive aluminum support itself, and surface direction unevenness can occur in an output image due to the deviation.

[0013] In order to solve this problem, the inventors of the present application researched crystal grains of a surface of an aluminum support.

[0014] As a result of the research, the inventors found that in an electrophotographic photosensitive member including a support having a cylindrical shape, and a photosensitive layer formed on the support, when the support contains at least one of aluminum or an aluminum alloy, and when an area at a time of a maximum frequency calculated from an area distribution curve of aluminum crystal grains of a surface of the support is represented by A (μm 2 ), and a half width of a maximum peak in the area distribution curve is represented by B (μm 2 ), the support satisfies the following formula (1).

[0015] B / A ≤ 1.0 … (1)

[0016] The inventors of the present application assumed that a mechanism by which surface direction unevenness of an output image can be reduced by the configuration of the present application is as described below.

[0017] Aluminum crystal grains generally have random sizes. The inventors of the present application surmised that the ease of electron flow in a crystal slightly differs depending on the size of aluminum crystal grains, that is, the smaller the crystal grains, the greater the influence of grain boundaries between the crystal grains on the ease of electron flow, and thus the more difficult the electron flow.

[0018] In the aluminum support used in existing electrophotographic photosensitive components, the aluminum grains have random sizes. Therefore, the grains differ in the ease with which electrons flow. When image formation is repeated, the differences in the ease of electron flow between the grains become more significant, resulting in surface orientation non-uniformity of the photosensitive component's potential. Image formation is based on potential, therefore the potential is proportional to the magnitude of this non-uniformity in the output image. Surface orientation non-uniformity may occur in the output image for the reasons described above.

[0019] Therefore, it is speculated that when the size of the aluminum grains used to form the surface of the aluminum support is close to a homogeneous state, the current flowing through the aluminum support is homogenized to reduce potential non-uniformity, thereby reducing surface orientation non-uniformity in the output image. The fact that the size of the aluminum grains used to form the surface of the aluminum support is homogenized can be determined from the area of ​​the aluminum grains.

[0020] The effects of the present invention can be achieved when the components influence each other synergistically as described in the aforementioned mechanism.

[0021] [Electronic photographic sensor]

[0022] The electrophotographic photosensitive component of the present invention is characterized by comprising a support, a charge generating layer, and a charge transporting layer, the surface of which is formed of at least one of aluminum or an aluminum alloy. A film of aluminum hydroxide and / or aluminum oxide may be formed on the surface of the support.

[0023] An example of a method for producing an electrophotographic photosensitive component of the present invention is a method comprising the following steps: preparing a coating liquid for each layer described below; applying the liquid in a desired layer sequence; and drying the liquid. In this case, examples of methods for applying the coating liquid include dip coating, spray coating, inkjet coating, roller coating, die coating, blade coating, curtain coating, wire rod coating, and ring coating. From the viewpoint of efficiency and productivity, dip coating is preferred.

[0024] The support structure and each layer are described below.

[0025] <Support Body>

[0026] The electrophotographic photosensitive component of the present invention includes a cylindrical support body whose surface is formed of at least one of aluminum or aluminum alloy. Furthermore, the surface of the support body can be subjected to, for example, hot water treatment, sandblasting, or machining treatment.

[0027] (1) Area distribution curve of grains

[0028] The area of ​​the aluminum grains at the maximum frequency, calculated from the area distribution curve of the aluminum grains on the support surface, is given by A(μm). 2 The half-width of the maximum peak in the area distribution curves of aluminum grains is represented by B(μm).2 When expressed as ), the ratio B / A is less than 1.0.

[0029] From the viewpoint of minimizing the difference in the ease of electron flow between grains, the ratio B / A is preferably 0.7 or less. Furthermore, when the ratio B / A is 0.5 or less, the effects of the present invention can be obtained more satisfactorily.

[0030] (2) Regarding the average area of ​​the grains

[0031] The average area of ​​aluminum grains is preferably 10 μm. 2 The above applies when the average area of ​​aluminum grains is 10 μm. 2 In this case, the ease of electron flow is almost unaffected by grain boundaries between grains, thus suppressing initial charge retention on the support. As a result, short-term potential fluctuations can be reduced.

[0032] (Methods for measuring grain area)

[0033] For example, the area of ​​a grain can be measured as described below.

[0034] The area of ​​the grains can be observed and measured using an electron microscope (e.g., the VE series manufactured by Keyence Corporation).

[0035] Four 10mm square slices are cut from the photosensitive element at 90° intervals along its circumference, at positions 40mm from each end of the photosensitive element's axial direction and at the center of the photosensitive element's axial direction (a total of 4×3=12 positions), together with the support body. When the length of the support body is 297mm, the ends of the photosensitive element are specifically, for example, positions 40mm, 18.5mm, or 8.5mm from each end of the photosensitive element's axial direction.

[0036] The protective layer of each slice was removed by grinding with a grinding wheel, and the photosensitive layer was removed with methyl ethyl ketone. Then, the surface of the support was exposed by polishing and mirror finishing. Next, the slice was treated by immersing it in an aqueous sodium hydroxide solution for 1 minute to obtain a sample for measuring the grain area.

[0037] A 100-micrometer square area on the surface of the sample was observed using an electron microscope, and the area of ​​its grains was calculated using the microscope's standard image processing software. Aluminum hydroxide and / or aluminum oxide grains are present on the sample surface, so the observed grains could be these grains. However, the film of aluminum hydroxide and / or aluminum oxide on the sample surface is so thin that the electron beam penetrates the film during electron microscopy, allowing the aluminum grains to be observed. Therefore, in this invention, aluminum grains include not only aluminum grains but also aluminum hydroxide and aluminum oxide grains.

[0038] At this time, as Figure 1A As shown by the diagonal lines, grains whose overall shape cannot be seen in the microscope image are manually excluded.

[0039] (Method for preparing grain area distribution curves)

[0040] First, the average area of ​​the grains observed in the samples obtained from the 12 locations described above is calculated. The frequency of the grain area is calculated by incrementing or subtracting 1 / 20 of the obtained average area, and a grain area distribution curve is plotted. Specifically, the frequency of the grain area is calculated from the average area by incrementing or subtracting it. For example, when the average area is 50 μm... 2 At that time, from 50μm 2 With 2.5μm 2 Increment or 2.5μm 2 The frequency of grain area is calculated by subtracting the amount. And the following is fabricated: Figure 1B The area distribution curve shown. Figure 1B The area distribution curve shown is the normal distribution curve that best suits the area frequency. The area at the maximum frequency calculated from the area distribution curve is given by A(μm). 2 ) represents the range (width of the horizontal axis) of the area distribution curve that has a value equal to half the maximum frequency, i.e., the half-width of the maximum peak in the area distribution curve (the half-width of the peak of the normal distribution curve), which is represented by B(μm). 2 )express.

[0041] (3) About aluminum alloys

[0042] When the support body contains an aluminum alloy, the aluminum alloy is preferably a 3000 series aluminum alloy or a 6000 series aluminum alloy. An example of a 3000 series aluminum alloy is JIS 3003 alloy, which is specifically an aluminum alloy containing less than 0.6% by mass of silicon, less than 0.7% by mass of iron, more than 0.05% by mass and less than 0.2% by mass of copper, more than 1.0% by mass and less than 1.5% by mass of manganese, and less than 0.1% by mass of zinc, and contains aluminum and impurities as the balance. Another example of a 6000 series aluminum alloy is the JIS 6063 alloy, specifically an aluminum alloy containing 0.2% to 0.6% by mass of silicon, 0.35% to 0.35% by mass of iron, 0.1% to 0.1% by mass of copper, 0.1% to 0.1% by mass of manganese, 0.45% to 0.9% by mass of magnesium, 0.1% to 0.1% by mass of chromium, 0.1% to 0.1% by mass of zinc, and 0.1% to 0.1% by mass of titanium, with aluminum and impurities as the balance. To control the grain area distribution, this type of 3000 series or 6000 series aluminum alloy is preferred.

[0043] (4) Regarding the production method of the support body

[0044] There are no particular restrictions on the production method of the support body, as long as the support body to be produced meets the requirements of this invention.

[0045] An example of a method for producing a support is a method comprising the following steps: a step of preparing aluminum or a specific aluminum alloy; a first step of hot extruding the prepared aluminum or aluminum alloy to obtain a shaped body; a second step of cold drawing the shaped body obtained in the first step; a third step of annealing the obtained product after the second step; and a step of cutting the surface of the annealed product after the third step.

[0046] In this method, the area of ​​the support grains can be controlled by the heating time, temperature, holding time and cooling time in the annealing process of the third step.

[0047] Specifically, setting the annealing temperature to 405°C to 450°C can narrow the grain area distribution. Furthermore, the grain area varies with the heating and cooling rates; therefore, it is preferable to control the heating rate to below 40°C / min and the cooling rate to below 5°C / min. It is also preferable to set the holding time to 2 hours or more to allow for sufficient recrystallization.

[0048] In addition, thermal history is important when controlling the grain area, so it is preferable to produce the support by annealing the product that has undergone the first and second processes described above.

[0049] <Conductive Layer>

[0050] In the electrophotographic photosensitive component of the present invention, a conductive layer can be provided on the support. The conductive layer can mask damage and unevenness on the surface of the support and control the reflection of light on the surface of the support.

[0051] The conductive layer preferably comprises conductive particles and resin.

[0052] The materials used for conductive particles are, for example, metal oxides, metals, or carbon black.

[0053] Examples of metal oxides include zinc oxide, aluminum oxide, indium oxide, silicon oxide, zirconium oxide, tin oxide, titanium oxide, magnesium oxide, antimony oxide, and bismuth oxide. Examples of metals include aluminum, nickel, iron, nickel-chromium alloys, copper, zinc, and silver.

[0054] Preferably, metal oxides are used as conductive particles, and more particularly, titanium oxide, tin oxide and zinc oxide are preferred.

[0055] When using metal oxides as conductive particles, the surface of the metal oxides can be treated with silane coupling agents, or the metal oxides can be doped with elements such as phosphorus or aluminum, or their oxides.

[0056] Furthermore, each conductive particle can be a laminate consisting of a core particle and a capping layer covering the particle. Examples of core particles include titanium oxide, barium sulfate, and zinc oxide. The capping layer is, for example, a metal oxide, such as tin oxide.

[0057] Furthermore, when metal oxides are used as conductive particles, their volume average particle size is preferably 1 nm or more and 500 nm or less, more preferably 3 nm or more and 400 nm or less.

[0058] Examples of resins include polyester resins, polycarbonate resins, polyvinyl acetal resins, acrylic resins, silicone resins, epoxy resins, melamine resins, polyurethane resins, phenolic resins, and alkyd resins.

[0059] In addition, the conductive layer may further contain masking agents, such as silicone oil, resin particles, or titanium dioxide.

[0060] The average thickness of the conductive layer is preferably 1 μm or more and 50 μm or less, and particularly preferably 3 μm or more and 40 μm or less.

[0061] A conductive layer can be formed by preparing a coating liquid containing the above-mentioned materials and solvents, forming a coating film thereon, and drying the coating film. Examples of solvents used in the coating liquid include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. As a dispersion method for dispersing conductive particles in a coating liquid for a conductive layer, methods using paint mixers, sand mills, ball mills, and high-speed liquid impact dispersers are provided.

[0062] <Undercoat>

[0063] In the electrophotographic photosensitive component of the present invention, an undercoating layer can be provided on the support or conductive layer. The undercoating layer can improve the interlayer adhesion to impart charge injection suppression function.

[0064] The primer layer preferably comprises a resin. Alternatively, the primer layer can be formed into a cured film by polymerizing a composition comprising monomers having polymerizable functional groups.

[0065] Examples of resins include polyester resins, polycarbonate resins, polyvinyl acetal resins, acrylic resins, epoxy resins, melamine resins, polyurethane resins, phenolic resins, polyvinylphenol resins, alkyd resins, polyvinyl alcohol resins, polyethylene oxide resins, polypropylene oxide resins, polyamide resins, polyamic acid resins, polyimide resins, polyamide-imide resins, and cellulose resins.

[0066] Examples of polymerizable functional groups in monomers include isocyanate groups, terminal isocyanate groups, hydroxymethyl groups, alkylated hydroxymethyl groups, epoxy groups, metal alkoxide groups, hydroxyl groups, amino groups, carboxyl groups, thiol groups, carboxylic anhydride groups, and carbon-carbon double bond groups.

[0067] Furthermore, to improve electrical properties, the base coating may further include electron transport materials, metal oxides, metals, and conductive polymers. Among these, electron transport materials and metal oxides are preferred.

[0068] Examples of electron transport materials include quinone compounds, imide compounds, benzimidazole compounds, cyclopentadienyl compounds, fluorenone compounds, xanthonesone compounds, benzophenone compounds, cyanovinyl compounds, halogenated aryl compounds, thiophene compounds, and boron-containing compounds. Electron transport materials with polymerizable functional groups can be used as electron transport materials and copolymerized with the aforementioned monomers with polymerizable functional groups to form a base coating as a cured film.

[0069] Examples of metal oxides include indium tin oxide, tin oxide, indium oxide, titanium oxide, zinc oxide, aluminum oxide, and silicon dioxide. Examples of metals include gold, silver, and aluminum.

[0070] In addition, the base coat may contain additives.

[0071] The average thickness of the base coating is preferably 0.1 μm or more and 50 μm or less, more preferably 0.2 μm or more and 40 μm or less, and particularly preferably 0.3 μm or more and 30 μm or less.

[0072] The base coat can be formed by preparing a coating liquid containing the above-described materials and solvents, forming a coating film thereon, and drying and / or curing the coating film. Examples of solvents used in the coating liquid include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents.

[0073] <Photosensitive layer>

[0074] In the electrophotographic photosensitive component of the present invention, the photosensitive layer may be mainly (1) a laminated photosensitive layer or (2) a single-layer photosensitive layer. (1) The laminated photosensitive layer has a charge-generating layer containing a charge-generating substance and a charge-transporting layer containing a charge-transporting substance. (2) The single-layer photosensitive layer has a photosensitive layer containing both a charge-generating substance and a charge-transporting substance.

[0075] (1) Laminated photosensitive layer

[0076] Laminated photosensitive layers consist of a charge generation layer and a charge transport layer.

[0077] (1-1) Charge generation layer

[0078] The charge-generating layer preferably comprises a charge-generating substance and a resin.

[0079] Examples of charge-generating substances include azo pigments, perylene pigments, polycyclic quinone pigments, indigo pigments, and phthalocyanine pigments. Among these, azo pigments and phthalocyanine pigments are preferred. Of the phthalocyanine pigments, titanium dioxide phthalocyanine pigments, gallium chloride phthalocyanine pigments, and hydroxy gallium phthalocyanine pigments are preferred.

[0080] The content of charge-generating material in the charge-generating layer is preferably 40% by mass or more and 85% by mass or less relative to the total mass of the charge-generating layer, more preferably 60% by mass or more and 80% by mass or less.

[0081] Examples of resins include polyester resins, polycarbonate resins, polyvinyl alcohol acetal resins, polyvinyl alcohol butyral resins, acrylic resins, silicone resins, epoxy resins, melamine resins, polyurethane resins, phenolic resins, polyvinyl alcohol resins, cellulose resins, polystyrene resins, polyvinyl acetate resins, and polyvinyl chloride resins. Among these, polyvinyl alcohol butyral resin is more preferred.

[0082] Furthermore, the charge-generating layer may further contain additives such as antioxidants or ultraviolet absorbers. Specific examples include hindered phenolic compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, and benzophenone compounds.

[0083] The average thickness of the charge generation layer is preferably 0.1 μm or more and 1 μm or less, more preferably 0.15 μm or more and 0.4 μm or less.

[0084] The charge-generating layer can be formed by preparing a coating solution containing the above-described materials and solvents, forming a coating film thereon, and drying the coating film. Examples of solvents used in the coating solution include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents.

[0085] (1-2) Charge transport layer

[0086] The charge transport layer preferably comprises a charge transport material and a resin.

[0087] Examples of charge-transporting substances include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having groups derived from each of these substances. Among these, triarylamine compounds and benzidine compounds are preferred.

[0088] The content of charge transport material in the charge transport layer is preferably 25% by mass or more and 70% by mass or less relative to the total mass of the charge transport layer, more preferably 30% by mass or more and 55% by mass or less.

[0089] Examples of resins include polyester resins, polycarbonate resins, acrylic resins, and polystyrene resins. Among these, polycarbonate resins and polyester resins are preferred. As a polyester resin, polyarylate resins are particularly preferred.

[0090] The ratio (mass ratio) of charge transport material to resin is preferably 4:10 to 20:10, more preferably 5:10 to 12:10.

[0091] In addition, the charge transport layer may contain additives such as antioxidants, UV absorbers, plasticizers, leveling agents, lubricants, or wear resistance improvers. Specific examples include hindered phenolic compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane-modified resins, silicone oils, fluoropolymer particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, and boron nitride particles.

[0092] The average thickness of the charge transport layer is 5 μm or more and 50 μm or less, more preferably 8 μm or more and 40 μm or less, and particularly preferably 10 μm or more and 30 μm or less.

[0093] The charge transport layer can be formed by preparing a coating solution containing the above-described materials and solvents, forming a coating film thereon, and drying the coating film. Examples of solvents used in the coating solution include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. Among these solvents, ether-based solvents or aromatic hydrocarbon-based solvents are preferred.

[0094] (2) Single-layer photosensitive layer

[0095] A single-layer photosensitive layer can be formed by preparing a coating solution containing a charge-generating substance, a charge-transporting substance, a resin, and a solvent, forming a coating film, and drying the coating film. Examples of charge-generating substances, charge-transporting substances, and resins are the same as those in the section “(1) Laminated Photosensitive Layers”.

[0096] <Protective Layer>

[0097] In the electrophotographic photosensitive component of the present invention, a protective layer can be provided on the photosensitive layer. The provision of the protective layer can improve durability.

[0098] The protective layer preferably comprises conductive particles and / or charge-transporting substances, as well as resin.

[0099] Examples of conductive particles include particles of metal oxides such as titanium oxide, zinc oxide, tin oxide, and indium oxide.

[0100] Examples of charge-transporting substances include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having groups derived from each of these substances. Among these, triarylamine compounds and benzidine compounds are preferred.

[0101] Examples of resins include polyester resins, acrylic resins, phenoxy resins, polycarbonate resins, polystyrene resins, phenolic resins, melamine resins, and epoxy resins. Among these, polycarbonate resins, polyester resins, and acrylic resins are preferred.

[0102] Alternatively, the protective layer can be formed into a cured film by polymerizing a composition containing monomers with polymerizable functional groups. Examples of reactions in this case include thermal polymerization, photopolymerization, and radiation polymerization. Examples of polymerizable functional groups in monomers include acrylate and methacrylate groups. Materials with charge-transporting capabilities can be used as monomers with polymerizable functional groups.

[0103] The protective layer may contain additives such as antioxidants, UV absorbers, plasticizers, leveling agents, lubricants, or wear resistance improvers. Specific examples include hindered phenolic compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane-modified resins, silicone oils, fluoropolymer particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, and boron nitride particles.

[0104] The average thickness of the protective layer is preferably 0.5 μm or more and 10 μm or less, more preferably 1 μm or more and 7 μm or less.

[0105] A protective layer can be formed by preparing a coating liquid containing the above-mentioned materials and solvents, forming a coating film thereon, and drying and / or curing the coating film. Examples of solvents used in the coating liquid include alcohol solvents, ketone solvents, ether solvents, sulfoxide solvents, ester solvents, and aromatic hydrocarbon solvents.

[0106] [Processing box and electrophotographic equipment]

[0107] The processing box of the present invention is characterized in that the box integrally supports the above-mentioned electrophotographic photosensitive component and at least one unit selected from the group consisting of a charging unit, a developing unit and a cleaning unit, and is detachably mounted to the main body of the electrophotographic device.

[0108] Furthermore, the electrophotographic apparatus of the present invention is characterized by including the aforementioned electrophotographic photosensitive component, charging unit, exposure unit, developing unit, and transfer unit.

[0109] Figure 2The illustration shows an example of a schematic configuration of an electrophotographic device having a processing box including an electrophotographic photosensitive element.

[0110] An electrophotographic photosensitive element 1, which is cylindrical in shape, is driven to rotate around an axis 2 at a predetermined circumferential speed in the direction indicated by the arrow. The surface of the electrophotographic photosensitive element 1 is charged to a predetermined positive or negative potential by a charging unit 3. Although a roller charging system based on a roller-type charging element is shown in the figure, charging systems such as corona charging systems, proximity charging systems, or injection charging systems can also be used. The charged surface of the electrophotographic photosensitive element 1 is irradiated with exposure light 4 from an exposure unit (not shown), thus forming an electrostatic latent image corresponding to the target image information thereon. The electrostatic latent image formed on the surface of the electrophotographic photosensitive element 1 is developed using toner stored in a developing unit 5, and a toner image is formed on the surface of the electrophotographic photosensitive element 1. The toner image formed on the surface of the electrophotographic photosensitive element 1 is transferred to a transfer material 7 by a transfer unit 6. The transfer material 7, on which the toner image is transferred, is conveyed to a fixing unit 8 for fixing the toner image and then printed out to the outside of the electrophotographic device. Electrophotographic equipment may include a cleaning unit 9 for removing, for example, toner residues remaining on the surface of the electrophotographic photosensitive member 1 after transfer. Alternatively, a so-called cleanerless system configured to remove residues using a developing unit or similar means may be used without a separate cleaning unit. Electrophotographic equipment may include a static removal mechanism configured to perform static removal treatment on the surface of the electrophotographic photosensitive member 1 using pre-exposure light 10 from a pre-exposure unit (not shown). Furthermore, a guide unit 12, such as a track, may be provided for detachably mounting the processing cartridge 11 of the present invention to the main body of the electrophotographic equipment.

[0111] The electrophotographic photosensitive element of the present invention can be used in, for example, laser beam printers, LED printers, copiers, fax machines, and multifunction printers.

[0112] [Example]

[0113] The invention is described in more detail below with the aid of embodiments and comparative examples. The invention is by no means limited to the following embodiments, and various modifications can be made without departing from the spirit of the invention. In the following description of the embodiments, unless otherwise stated, "parts" are based on mass.

[0114] [Manufacturing method of support body]

[0115] The support body is produced using the following method.

[0116] (Production example of support body A-1)

[0117] The extruded tube, formed from JIS 3003 alloy and hot-extruded, is cold-drawn to obtain a drawn tube with an outer diameter of 30.8 mm, an inner diameter of 28.5 mm, and a length of 370 mm.

[0118] Next, the drawn tube was placed in an electric furnace and annealed while being heated at a rate of 5°C / min and held at 450°C for 2.5 hours. Afterward, the annealed product was cooled at a rate of 1°C / min, and after 24 hours, the cooled product was removed from the furnace. Details are shown in Table 1.

[0119] After annealing, the surface of the resulting material is mirror-finished. This yields a support body A-1 with an outer diameter of 30.5 mm, an inner diameter of 28.5 mm, and a length of 370 mm.

[0120] Elemental analysis of the drawn tubes used showed that the tubes were formed from an aluminum alloy containing 0.16% by mass silicon, 0.2% by mass iron, 0.08% by mass copper, 1.3% by mass manganese, and 0.02% by mass zinc, with aluminum and impurities as the balance.

[0121] (Production examples of supports A-2 to A-13)

[0122] Except for using the same drawn tube as in the production example of support body A-1, and changing the annealing conditions as shown in Table 1, each support body is produced in the same manner as in the production example of support body A-1. The resulting supports bodies are defined as support bodies A-2 to support bodies A-13.

[0123] (Production example of support body A-14)

[0124] The extruded tube, formed from JIS 3003 alloy and hot-extruded, is cold-drawn to obtain a drawn tube with an outer diameter of 30.8 mm, an inner diameter of 28.5 mm, and a length of 370 mm.

[0125] Next, the drawn tube was placed in an electric furnace and annealed while being heated at a rate of 5°C / min and held at 435°C for 2.5 hours. Afterward, the annealed product was cooled at a rate of 1°C / min, and after 24 hours, the cooled product was removed from the furnace. Details are shown in Table 1.

[0126] After annealing, the surface of the resulting material is mirror-finished. This yields a support body A-14 with an outer diameter of 30.5 mm, an inner diameter of 28.5 mm, and a length of 370 mm.

[0127] Elemental analysis of the drawn tubes used showed that the tubes were formed from an aluminum alloy containing 0.5% by mass silicon, 0.6% by mass iron, 0.15% by mass copper, 1.2% by mass manganese, and 0.08% by mass zinc, with aluminum and impurities as the balance.

[0128] (Production example of support body B-1)

[0129] The extruded tube, formed from JIS 6063 alloy and hot-extruded, is cold-drawn to obtain a drawn tube with an outer diameter of 30.8 mm, an inner diameter of 28.5 mm, and a length of 370 mm.

[0130] Next, the drawn tube was placed in an electric furnace and annealed while being heated at a rate of 5°C / min and held at 450°C for 2.5 hours. Afterward, the annealed product was cooled at a rate of 1°C / min, and after 24 hours, the cooled product was removed from the furnace. Details are shown in Table 1.

[0131] After annealing, the surface of the resulting material is mirror-finished. This yields a support body B-1 with an outer diameter of 30.5 mm, an inner diameter of 28.5 mm, and a length of 370 mm.

[0132] Elemental analysis of the drawn tubes used showed that the tubes were formed from an aluminum alloy containing 0.5% by mass silicon, 0.3% by mass iron, 0.07% by mass copper, 0.08% by mass manganese, 0.7% by mass magnesium, 0.04% by mass chromium, 0.08% by mass zinc, and 0.06% by mass titanium, with aluminum and impurities as the balance.

[0133] (Production examples of supports B-2 to B-13)

[0134] Except for using the same drawn tube as in the production example of support body B-1, and changing the annealing conditions as shown in Table 1, each support body is produced in the same manner as in the production example of support body B-1. The resulting supports bodies are defined as support bodies B-2 to support bodies B-13.

[0135] (Production examples of support bodies C-1 to C-11)

[0136] Except for the example of producing support A-1, in which a drawn tube with an outer diameter of 30.8 mm, an inner diameter of 28.5 mm, and a length of 370 mm was obtained by cold drawing an extruded tube formed from JIS 3003 alloy and hot-extruded, and the annealing conditions were changed as shown in Table 1, each support was produced in the same manner as in the example of producing support A-1. The resulting supports are defined as supports C-1 to supports C-11.

[0137] (Production examples of support bodies C-12 and C-13)

[0138] Drawing tubes with an outer diameter of 30.8 mm, an inner diameter of 28.5 mm, and a length of 370 mm, respectively, made from an aluminum-magnesium (Al-Mg) alloy containing 2.5% magnesium by mass, were annealed under the conditions shown in Table 1. After annealing, the surfaces of the resulting materials were mirror-finished. This yielded supports C-12 and C-13 with an outer diameter of 30.5 mm, an inner diameter of 28.5 mm, and a length of 370 mm.

[0139] (Production examples of support bodies D-1 to D-11)

[0140] Except for the example of producing support body B-1, in which a drawn tube with an outer diameter of 30.8 mm, an inner diameter of 28.5 mm, and a length of 370 mm is obtained by cold drawing an extruded tube formed from JIS 6063 alloy and hot-extruded, and the annealing conditions are changed as shown in Table 1, each support body is produced in the same manner as in the example of producing support body B-1. The resulting supports bodies are defined as supports D-1 to supports D-11.

[0141] Table 1

[0142]

[0143] <Production of Electrophotographic Photosensitive Components>

[0144] (Production example of photosensitive component A-1)

[0145] Support A-1 is used as the support, and an undercoat, a charge generation layer, a charge transport layer and a protective layer are formed as described below.

[0146] <Formation of the base coating>

[0147] 100 parts of zinc oxide particles (specific surface area: 19 m²) were used as metal oxides. 2 / g, powder resistivity: 3.6×10 6The zinc oxide granules were mixed with 500 parts of toluene (Ω·cm) and 0.8 parts of N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane (trade name: KBM-602, manufactured by Shin-Etsu Chemical Co., Ltd.) as a silane coupling agent, followed by stirring for 6 hours. The toluene was then evaporated under reduced pressure, and the residue was dried at 130°C for 6 hours to obtain surface-treated zinc oxide particles.

[0148] Next, 15 parts of butyraldehyde resin (trade name: BM-1, manufactured by Sekisui Chemical Company, Limited) and 15 parts of capped isocyanate (trade name: Sumidur 3175, manufactured by Sumika Bayer Urethane Co., Ltd.) were dissolved in a mixed solution of 73.5 parts of methyl ethyl ketone and 73.5 parts of 1-butanol. 80.8 parts of the surface-treated zinc oxide particles obtained above and 0.8 parts of 2,3,4-trihydroxybenzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to the solution, and the mixture was dispersed for 3 hours at 23°C ± 3°C using a sand mill with glass beads of 0.8 mm diameter. After dispersion, 0.01 parts of silicone oil (trade name: SH28PA, manufactured by Dow Corning Toray Silicone Co., Ltd.) and 5.6 parts of crosslinked polymethyl methacrylate particles (trade name: TECHPOLYMER SSX-102, manufactured by Sekisui Kasei Co., Ltd., average primary particle size: 2.5 μm) were added to the dispersion, and the mixture was stirred to prepare a coating liquid for the primer layer.

[0149] The primer layer was applied to the support A-1 by dip coating, and the resulting coating was dried at 160°C for 40 minutes to form a primer layer with a thickness of 18 μm.

[0150] <Formation of the charge generation layer>

[0151] Twenty parts of crystalline gallium phthalocyanine crystals (charge-generating material) exhibiting peaks at Bragg angles of 7.4° and 28.2° (2θ±0.2°) in CuKα characteristic X-ray diffraction, 0.2 parts of a calixarene compound represented by formula (A), 10 parts of polyvinyl butyral (trade name: S-LEC BX-1, manufactured by Sekisui Chemical Company, Limited), and 600 parts of cyclohexanone were placed in a sand mill using glass beads with a diameter of 1 mm, and the mixture was dispersed for 4 hours. Then, 700 parts of ethyl acetate were added to the dispersion to prepare a coating solution for the charge-generating layer. The coating solution for the charge-generating layer was applied to the base layer by dip coating, and the resulting coating was dried at 80°C for 15 minutes to form a charge-generating layer with a thickness of 0.17 μm.

[0152]

[0153] <Formation of the charge transport layer>

[0154] A coating solution for the charge transport layer was prepared by dissolving 30 parts of a compound (charge transport substance) represented by formula (B), 60 parts of a compound (charge transport substance) represented by formula (C), 10 parts of a compound (charge transport substance) represented by formula (D), 100 parts of polycarbonate resin (trade name: IUPILON Z400, manufactured by Mitsubishi Engineering-Plastics Corporation, bisphenol Z-type polycarbonate), and 0.02 parts of polycarbonate (viscosity average molecular weight Mv: 20,000) represented by formula (E) in a mixed solvent of 600 parts of mixed xylene and 200 parts of dimethoxymethane. The coating solution for the charge transport layer was applied to the charge generation layer by dip coating to form a coating film, and the resulting coating film was dried at 100°C for 30 minutes to form a charge transport layer with a thickness of 18 μm.

[0155]

[0156] <Formation of the protective layer>

[0157] A mixed solvent of 20 parts of 1,1,2,2,3,3,4-heptafluorocyclopentane (trade name: ZEORORA H, manufactured by Zeon Corporation) and 20 parts of 1-propanol was filtered using a polytetrafluoroethylene filter (trade name: PF-040, manufactured by Advantec Toyo Kaisha, Ltd.). Then, 90 parts of a hole-transporting compound represented by formula (F), 70 parts of 1,1,2,2,3,3,4-heptafluorocyclopentane, and 70 parts of 1-propanol were added to the mixed solvent. The mixture was then filtered again using a polytetrafluoroethylene filter (trade name: PF-020, manufactured by Advantec Toyo Kaisha, Ltd.) to prepare a coating solution for the protective layer. The coating solution for the protective layer was applied to the charge transport layer by dip coating, and the resulting coating was dried in air at 50°C for 6 minutes. Subsequently, in nitrogen atmosphere, while rotating the support (the irradiated object) at 200 rpm, the coating was irradiated with an electron beam for 1.6 seconds at an accelerating voltage of 70 kV and an absorbed dose of 8,000 Gy. The coating was then heated in nitrogen atmosphere by increasing its temperature from 25°C to 125°C over 30 seconds. The oxygen concentration in the atmosphere during electron beam irradiation and post-irradiation heating was 15 ppm. Next, the coating was heat-treated in atmospheric atmosphere at 100°C for 30 minutes to form a 5-micrometer-thick protective layer cured by the electron beam.

[0158]

[0159] <Surface processing of photosensitive components>

[0160] The protective layer surface was ground using an abrasive disc (trade name: GC3000, manufactured by Ricken Corundum Co., Ltd.). The feed rate of the abrasive disc was set to 40 mm / min, the rotation speed of the workpiece was set to 240 rpm, and the pressing pressure of the abrasive disc on the protective layer was set to 7.5 N / m. 2 The feed direction of the abrasive pad is set to be the same as the rotation direction of the photosensitive component. A support roller with an outer diameter of 40 cm and an Asker C hardness of 40 is used. Under these conditions, linear grooves are formed on the outer peripheral surface of the protective layer for 10 seconds. Thus, photosensitive component A-1 is produced.

[0161] (Production examples of photosensitive components A-2 to A-14)

[0162] Except for using the support shown in Table 2, each electrophotographic photosensitive element is manufactured in exactly the same manner as photosensitive element A-1. The resulting electrophotographic photosensitive elements are defined as "photosensitive elements A-2 to A-14".

[0163] (Production examples of photosensitive components B-1 to B-13)

[0164] Except for using the support shown in Table 2, each electrophotographic photosensitive element is manufactured in exactly the same manner as photosensitive element A-1. The resulting electrophotographic photosensitive elements are defined as "photosensitive elements B-1 to B-13".

[0165] (Production examples of photosensitive components C-1 to C-13)

[0166] Except for using the support shown in Table 2, each electrophotographic photosensitive element is manufactured in exactly the same manner as photosensitive element A-1. The resulting electrophotographic photosensitive elements are defined as "photosensitive elements C-1 to C-13".

[0167] (Production examples of photosensitive components D-1 to D-11)

[0168] Except for using the support shown in Table 2, each electrophotographic photosensitive element is manufactured in exactly the same manner as photosensitive element A-1. The resulting electrophotographic photosensitive elements are defined as "photosensitive elements D-1 to D-11".

[0169] [evaluate]

[0170] (Example A-1)

[0171] <Evaluation of surface orientation non-uniformity>

[0172] The photosensitive element A-1 is installed on the cyan station of an electrophotographic device (copier) (trade name: imagePRESS C910, manufactured by Canon Inc.) used as an evaluation device.

[0173] First, the surface potential of the photosensitive element was measured by passing 30,000 sheets of paper through the environment at 27°C and 60% RH.

[0174] The surface potential of the photosensitive element A-1 was measured as follows: the developing cartridge was removed from the evaluation equipment; a potential probe (trade name: model 6000B-8, manufactured by Trek, Inc.) was placed at the location of the cartridge; and the measurement was performed using a surface potentiometer (model 344: manufactured by Trek, Inc.).

[0175] First, the dark potential (Vd) at the axial center of the photosensitive element A-1 was adjusted to -600V. Next, the bright potential (Vl) of the surface of the photosensitive element A-1 was evaluated under constant exposure conditions. Twelve points (totaling 36 points: 3 axial points × 12 circumferential points = 36 points) were measured at each of the following locations: the central position along the axial direction of the photosensitive element A-1 and positions 40mm from each end of the photosensitive element A-1. Then, the maximum and minimum surface potential values ​​at each of the 12 points along the circumference of the photosensitive element A-1 at each axial position were calculated. The maximum potential difference (V) calculated from the maximum and minimum surface potential values ​​at each axial position was defined as surface non-uniformity and evaluated according to the following levels. The evaluation results are shown in Table 2.

[0176] Among the following grades A to D, grade A is the highest evaluation, and when the photosensitive element is grade C or above, the photosensitive element achieves the effects of the present invention. Meanwhile, grade D is an evaluation of surface orientation non-uniformity at the same level as prior art photosensitive elements.

[0177] Grade A: Surface non-uniformity less than 10V.

[0178] Grade B: Surface non-uniformity is above 10V and below 15V.

[0179] Grade C: Surface non-uniformity is above 15V and below 20V.

[0180] Grade D: Surface non-uniformity is above 20V.

[0181] Evaluation of short-term potential fluctuations

[0182] Photosensitive element A-1 is prepared separately from the photosensitive element used for evaluating surface orientation non-uniformity and is mounted on the cyan station of an electrophotographic device (copier) (trade name: imagePRESS C910, manufactured by Canon Inc.) used as an evaluation device.

[0183] The surface potential of the photosensitive element A-1 was measured as follows: the developing cartridge was removed from the evaluation equipment; a potential probe (trade name: model 6000B-8, manufactured by Trek, Inc.) was placed at the location of the cartridge; and the measurement was performed using a surface potentiometer (model 344: manufactured by Trek, Inc.).

[0184] First, the dark potential (Vd) of the photosensitive element A-1 was adjusted to -600V. Next, the bright potential (Vl) of the surface of the photosensitive element A-1 was evaluated under constant exposure conditions. Twelve points (totaling 36 points: 3 axial points × 12 circumferential points = 36 points) were set at each of the following locations: the central position along the axial direction of the photosensitive element A-1 and positions 40mm from each end of the photosensitive element A-1. Then, the average bright potential along the circumferential direction of the photosensitive element A-1 at each axial position was calculated and defined as the initial potential at each axial position.

[0185] Next, the developing cassette was returned to its original position, and 1,000 sheets of paper were passed through it at 27°C and 60% RH. Afterward, the potential probe was repositioned in the cassette position, and the average value of the bright area potential in the circumferential direction of the photosensitive element A-1 at each axial position was calculated in the same manner as described above. This average value was defined as the durability potential at each axial position. Finally, the absolute value of the difference between the initial potential and the durability potential at each axial position was calculated. The average value of the difference at each position was calculated as the short-term potential fluctuation value and evaluated according to the following levels. The evaluation results are shown in Table 3.

[0186] In the following grades A and B, when the photosensitive element is grade A, it achieves the effects of the present invention. Meanwhile, grade B is an evaluation of short-term potential fluctuation values ​​at the same level as prior art photosensitive elements.

[0187] Level A: Short-term potential fluctuations are less than 10V.

[0188] Level B: Short-term voltage fluctuations are above 10V.

[0189] Area A (μm) at maximum frequency 2 ), half-width B (μm) 2 ), and the calculation of the ratio B / A>

[0190] For the photosensitive component A-1, which was evaluated for short-term potential fluctuations, slices approximately 10 mm square were cut at four locations (4 × 3 = 12 locations in total) along the circumference, spaced at 90° intervals at each of the two ends of its axial direction and at the center of its support. The protective layer of each slice was removed by grinding with an abrasive disc, and then the photosensitive layer was removed with methyl ethyl ketone. Afterward, the surface of the support was exposed by polishing and mirror finishing. Next, the slice was treated by immersing it in an aqueous sodium hydroxide solution for 1 minute to obtain a sample for measuring the grain area.

[0191] The surface area of ​​the obtained sample was observed using the method described above, covering a 100 μm square region, and the area of ​​its grains was calculated. Subsequently, a grain area distribution curve was generated using the same method, and the area A (μm) at the maximum frequency calculated from the grain area distribution curve was calculated. 2 The half-width B (μm) of the maximum peak in the area distribution curve and the area distribution curve. 2 Then, B / A was calculated. The evaluation results are shown in Table 2.

[0192] (Examples A-2 to A-14 and Examples B-1 to B-13)

[0193] In each of Examples A-2 to A-14 and Examples B-1 to B-13, except that the photosensitive element A-1 used in Example A-1 is changed to the photosensitive element shown in Table 2, the surface orientation non-uniformity and short-term potential fluctuations are evaluated in the same manner as in Example A-1, and the area A (μm) at the maximum frequency is calculated from the grain area distribution curve. 2 The half-width B (μm) of the maximum peak in the area distribution curve 2 ), and the calculation of the ratio B / A.

[0194] (Comparative Examples C-1 to C-13 and Comparative Examples D-1 to D-11)

[0195] In each of Comparative Examples C-1 to C-13 and Comparative Examples D-1 to D-11, except that the photosensitive element A-1 used in Example A-1 was changed to the photosensitive element shown in Table 2, the surface orientation non-uniformity was evaluated in the same manner as in Example A-1, and the area A (μm) at the maximum frequency calculated from the grain area distribution curve was measured. 2 The half-width B (μm) of the maximum peak in the area distribution curve 2 ), and the calculation of the ratio B / A.

[0196] Photosensitive elements C-1 to C-13 and D-1 to D-11 were prepared separately from the photosensitive elements used in the evaluation of surface orientation inhomogeneity. The area A (μm) at the maximum frequency was calculated from the grain area distribution curve. 2 ), half-width B (μm) 2 ), and the calculation of the ratio B / A.

[0197] Table 2

[0198]

[0199] Table 3

[0200]

[0201] As can be seen from the data shown in Table 2, the photosensitive element of the present invention with a B / A ratio of 1.0 or less exhibits a suppressive effect on surface orientation non-uniformity of the output image. It was also found that the photosensitive element with a B / A ratio of 0.7 or less, or even more specifically, a B / A ratio of 0.5 or less, exhibits a stronger suppressive effect on surface orientation non-uniformity of the output image.

[0202] Furthermore, as can be seen from the data shown in Table 3, when the average area of ​​aluminum grains is 10 μm... 2 The above results show an effect of reducing short-term potential fluctuations. This effect may be due to the fact that when the average area of ​​the aluminum grains is set to 10 μm... 2 In the above cases, the ease of electron flow is almost unaffected by grain boundaries between grains, thus suppressing the initial charge retention on the support.

[0203] While the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims is to be interpreted in the broadest sense to cover all such modifications and equivalent structures and functions.

Claims

1. An electrophotographic photosensitive component, comprising: It has a cylindrical support body; and The photosensitive layer formed on the support, The characteristic is that the support body is made of aluminum alloy, and When the area at the maximum frequency calculated from the area distribution curve of the aluminum grains on the surface of the support is represented by A, and the half-width of the maximum peak in the area distribution curve is represented by B, the support satisfies the following equation (1), where the units of A and B are μm. 2 , B / A≤1.0 Equation (1).

2. The electrophotographic photosensitive component according to claim 1, wherein the average area of ​​the aluminum grains calculated from the area distribution curve is 10 μm. 2 above.

3. The electrophotographic photosensitive component according to claim 1 or 2, wherein the support body satisfies the following formula (3), B / A≤0.5 (3).

4. The electrophotographic photosensitive component according to claim 1 or 2, wherein the support body is a support body made of an aluminum alloy comprising less than 0.6% by mass of silicon, less than 0.7% by mass of iron, more than 0.05% by mass and less than 0.2% by mass of copper, more than 1.0% by mass and less than 1.5% by mass of manganese, and less than 0.1% by mass of zinc, and comprising aluminum and impurities as the balance.

5. The electrophotographic photosensitive component according to claim 1 or 2, wherein the support body is a support body made of an aluminum alloy comprising 0.2% by mass and less than 0.6% by mass of silicon, 0.35% by mass and less than 0.1% by mass of copper, 0.1% by mass and less than 0.1% by mass of manganese, 0.45% by mass and less than 0.9% by mass of magnesium, 0.1% by mass and less than 0.1% by mass of chromium, 0.1% by mass and less than 0.1% by mass of zinc, and 0.1% by mass of titanium, and comprising aluminum and impurities as the balance.

6. A processing box, characterized in that, The processing box integrally supports the electrophotographic photosensitive component according to any one of claims 1-5 and at least one unit selected from the group consisting of a charging unit, a developing unit, and a cleaning unit, and the processing box is detachably mounted to the body of the electrophotographic device.

7. An electrophotographic device, characterized in that, It includes an electrophotographic photosensitive element, a charging unit, an exposure unit, a developing unit, and a transfer unit according to any one of claims 1-5.

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