Electrophotographic photoreceptor, process cartridge, and electrophotographic apparatus

Abstract

To provide an electrophotographic photoreceptor that exhibits sufficient photosensitivity characteristics even when a speed of an image forming process is increased.SOLUTION: An electrophotographic photoreceptor of the present invention has a cylindrical support, and a surface of the support is formed of Al or an Al alloy. In a surface direction of an aggregate structure of Al on the surface of the support, the surface of the support is a surface composed of three types of crystal grains: crystal grains of a surface having (α) a {001} orientation of -15° or more and less than +15°; crystal grains of a surface having (β) a {101} orientation of -15°or more and less than +15°; and crystal grains of a surface having (γ) a {111} orientation of -15°or more and less than +15°. In the surface of the support, an area occupied by one type of crystal grains of the three types of crystal grains accounts for 10% or less of a total area of the surface of the support, and an area occupied by remaining two types of crystal grains accounts for 90% or more of the total area of the surface of the support.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrophotographic photoreceptor, a process cartridge using the electrophotographic photoreceptor, and an electrophotographic apparatus. [Background technology]

[0002] In recent years, the user base for electrophotographic devices has diversified, and there is a growing demand for images that are faster, higher quality, and more stable. Patent Document 1 discloses an electrophotographic photoreceptor containing a specific perinone compound and polyurethane in an undercoat layer disposed on a conductive substrate, as a technique to improve charge retention. Patent Document 2 describes an electrophotographic photoreceptor that contains metal oxide particles and a specific electron-accepting compound in an undercoat layer arranged on a conductive substrate, as a technique to suppress the occurrence of afterimage phenomena caused by the retention of the history of the previous image. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-46640 [Patent Document 2] Patent No. 6838324 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] According to our research, the electrophotographic photoreceptors described in Patent Documents 1 and 2 had room for improvement in their photosensitivity characteristics, particularly when the speed of the image formation process was increased in order to further speed up the electrophotographic apparatus. Therefore, the object of the present invention is to provide an electrophotographic photoreceptor that has sufficient light sensitivity characteristics even when the speed of the image formation process is increased. [Means for solving the problem]

[0005] The above objective is achieved by the present invention as follows. That is, an electrophotographic photoreceptor according to one aspect of the present invention is An electrophotographic photoreceptor having a cylindrical support, an undercoat formed directly above the support, and a photosensitive layer formed on the undercoat, The undercoat contains at least one compound selected from the group consisting of the compound represented by formula (A1), the compound represented by formula (A2), the compound represented by formula (A3), the compound represented by formula (A4), and the compound represented by formula (A5). The surface of the support is formed of Al and / or an Al alloy. The surface of the support is subject to the following conditions (C3) An electrophotographic photoreceptor characterized by satisfying the following conditions. 。 ( C3) In the surface direction of the Al texture on the surface of the support, the surface of the support is (α){001} crystal grains with orientations between -15° and +15°. (β){10¹} crystal grains with orientations of -15° or greater and less than +15°, and (γ){111} crystal grains on a plane with orientations between -15° and +15°. The surface is composed of three types of crystal grains, and on the surface of the support, the area occupied by one of the three types of crystal grains is 10% or less of the total surface area of ​​the support, and the area occupied by the remaining two types of crystal grains is 90% or more of the total surface area of ​​the support. [ka] [ka] [ka] [ka] [ka] (Formula (A1 ) R 101 to R 106 , And in formula (A2) R 201 to R 210 each independently represent a hydrogen atom, a cyano group, a nitro group, a halogen atom, an alkoxycarbonyl group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heterocyclic group. One CH₂ of the alkyl group may be substituted with O or S, and one CH of the alkyl group may be substituted with N. The substituent of the substituted alkyl group is a group selected from the group consisting of an alkyl group, a hydroxy group, an aryl group, an alkoxycarbonyl group and a halogen atom. The substituent of the substituted aryl group is a group selected from the group consisting of a halogen atom, a nitro group, a cyano group, an alkyl group, an alkoxy group and a halogen-substituted alkyl group. R in Formula (A3) 301 to R 308 、 and 、 R in Formula (A4) 401 to R 408 each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, or a substituted or unsubstituted alkoxycarbonyl group having 1 to 10 carbon atoms. Alternatively, R 301 and R 302 , R 302 and R 303 , R 303 and R 304 , R 305 and R 306 , R 306 and R 307 , R 307 and R 308 , R 401 and R 402 , R 402 and R 403 , R 403 and R 404 , R 405 and R 406 , R406 and R 407 , and also, R 407 and R 408 These elements may be connected to each other independently to form a ring. In formula (A5) of n1 and n2 are, each Independent 、 Integers between 0 and 4 (inclusive) Show vinegar. However, n1 and n2 cannot be 0 at the same time. R 501 and R 502 It can be present or absent. but, R 501 and R 502 teeth, each Independent 、 Alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, or 、 An aryl group having 6 to 30 carbon atoms Show vinegar.)

[0006] Furthermore, a process cartridge according to another aspect of the present invention is characterized in that it integrally supports the electrophotographic photoreceptor and at least one means selected from the group consisting of a charging means, a developing means, and a cleaning means, and is detachably attached to the main body of an electrophotographic apparatus. Furthermore, an electrophotographic apparatus according to yet another aspect of the present invention is characterized by comprising the above-mentioned electrophotographic photoreceptor and at least one means selected from the group consisting of a charging means, an exposure means, a developing means, and a transfer means. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an electrophotographic photoreceptor that can obtain sufficient light sensitivity characteristics even when the speed of the image formation process is increased. [Brief explanation of the drawing]

[0008] [Figure 1] This is a diagram showing the distribution of aluminum crystal grains. [Figure 2] This figure shows the measurement locations of aluminum crystal grains in the support. [Figure 3]This figure shows an example of a schematic configuration of an electrophotographic apparatus equipped with a process cartridge having an electrophotographic photoreceptor related to the present invention. [Modes for carrying out the invention]

[0009] The present invention will be described in detail below with reference to preferred embodiments. The photosensitivity characteristic of an electrophotographic photoreceptor refers to how efficiently it can convert the amount of light energy irradiated during the exposure process into potential contrast. In other words, when a charged electrophotographic photoreceptor is irradiated with light of a desired energy level, the better the photosensitivity characteristic, the more efficiently the charge is canceled out and the closer the surface potential approaches 0V. Alternatively, the smaller the amount of light energy required to obtain the desired contrast potential, the better the photosensitivity characteristic. Good photosensitivity is desirable because it makes it easier to handle faster image formation processes. To improve the photosensitivity characteristics of electrophotographic photoreceptors, it is common to make adjustments to the type and amount of materials used in films such as the charge generation layer and charge transport layer, and various improvements have been made to date. The inventors have found that in an electrophotographic photoreceptor having a layered structure on an aluminum support, in which an undercoat containing the compounds indicated by (A1), (A2), (A3), (A4), and (A5) is provided, the photosensitivity characteristics can also be improved by modifying the support. To solve the above technical problems that occurred in the prior art, the inventors investigated the crystal grains on the surface of an aluminum support. As a result of this investigation, they found that the above technical problems can be solved by using the electrophotographic photoreceptor according to the present invention described below. That is, an electrophotographic photoreceptor according to one aspect of the present invention is An electrophotographic photoreceptor having a cylindrical support, an undercoat formed directly above the support, and a photosensitive layer formed on the undercoat, The undercoat contains at least one compound selected from the group consisting of the compound represented by formula (A1), the compound represented by formula (A2), the compound represented by formula (A3), the compound represented by formula (A4), and the compound represented by formula (A5). The surface of the support is formed of Al and / or an Al alloy. The surface of the support is subject to the following conditions (C3) An electrophotographic photoreceptor characterized by satisfying the following conditions. 。 ( C3) In the surface direction of the Al texture on the surface of the support, the surface of the support is (α){001} crystal grains with orientations between -15° and +15°. (β){10¹} crystal grains with orientations of -15° or greater and less than +15°, and (γ){111} crystal grains on a plane with orientations between -15° and +15°. The surface is composed of three types of crystal grains, and on the surface of the support, the area occupied by one of the three types of crystal grains is 10% or less of the total surface area of ​​the support, and the area occupied by the remaining two types of crystal grains is 90% or more of the total surface area of ​​the support. [ka] [ka] [ka] [ka] [ka] (Formula (A1 ) R 101 ~R 106 , And in formula (A2) R 201 ~R 210Each of these independently represents a hydrogen atom, a cyano group, a nitro group, a halogen atom, an alkoxycarbonyl group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heterocyclic group. One of the CH2 groups of the alkyl group may be substituted with O or S, and one of the CH groups of the alkyl group may be substituted with N. The substituent of the substituted alkyl group is a group selected from the group consisting of alkyl groups, hydroxyl groups, aryl groups, alkoxycarbonyl groups, and halogen atoms. The substituent of the substituted aryl group is a group selected from the group consisting of halogen atoms, nitro groups, cyano groups, alkyl groups, alkoxy groups, and halogen-substituted alkyl groups. R in formula (A3) 301 ~R 308 and R in formula (A4) 401 ~R 408 Each of these independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, or a substituted or unsubstituted alkoxycarbonyl group having 1 to 10 carbon atoms. Alternatively, R 301 and R 302 , R 302 and R 303 , R 303 and R 304 , R 305 and R 306 , R 306 and R 307 , R 307 and R 308 , R 401 and R 402 , R 402 and R 403 , R 403 and R 404 , R 405 and R 406 , R 406 and R 407 , and also, R 407 and R 408 These elements may be connected to each other independently to form a ring. In formula (A5) of n1 and n2 are, each Independent 、 Integers between 0 and 4 (inclusive) Show vinegar. However, n1 and n2 cannot be 0 at the same time. R 501 and R 502 It can be present or absent. but, R 501 and R 502 teeth, each Independent 、 Alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, or 、 An aryl group having 6 to 30 carbon atoms Show vinegar.)

[0010] The inventors speculate that the mechanism by which the configuration of the present invention can solve the above-mentioned technical problems in the prior art is as follows. First, there are three main crystal orientations for aluminum: {001}, {101}, and {111}. As described in "Koberniks" ([No.28] Vol.14 2005.OCT), typically, the crystal grains with each crystal orientation are distributed randomly, as shown in Figure 1(a), for example. In this invention, for crystal grains having the three crystal orientations described above, (α){001}Face with orientation -15° or greater and less than +15° (β){10¹}Face with orientation -15° or greater and less than +15° (γ){111}Face with orientation -15° or greater and less than +15° This is how it is written. For example, (α), that is, a plane with a {001} orientation of -15° or more and less than +15°, refers to a crystal plane in an aluminum (Al) crystal that has a variation in the planes of -15° or more and less than +15° from the {001} plane.

[0011] Thus, when the orientation of crystal grains is randomly distributed, there are a relatively large number of boundary regions where crystal grains with three different crystal orientations meet (hereinafter also abbreviated as triplicate crystal boundaries). According to the inventors' investigation, when using the compounds shown in (A1), (A2), (A3), (A4), and (A5) above, it was found that reducing the number of triplicate crystal boundaries improved the photosensitivity. In other words, the compounds shown in (A1), (A2), (A3), (A4), and (A5) above and the triplicate crystal boundaries are a combination that is unlikely to cause electrical interaction, and it is speculated that this is a factor that reduces the photosensitivity characteristics. In other words, in conventional aluminum supports, crystal grains with three different crystal orientations are randomly present, resulting in a relatively large number of tri-crystal boundaries. It is thought that slight electron stagnation occurs at these points, reducing photosensitivity. The inventors speculate that by forming the surface of the aluminum support with a small number of any of the (α), (β), or (γ) crystal grains, as shown in Figures 1(b) to 1(d), the number of three heterocrystalline boundaries is reduced, thereby decreasing the number of combinations in which electrical interaction between the compounds shown in (A1), (A2), (A3), (A4), and (A5) and the three heterocrystalline boundaries is unlikely to occur, and thus improving the photosensitivity characteristics. Embodiments of the present invention will be described in detail below with reference to the drawings.

[0012] [Electrophotographic photoconductor] The electrophotographic photoreceptor according to the present invention comprises a cylindrical support, an undercoat layer, and a photosensitive layer. A method for manufacturing an electrophotographic photoreceptor according to the present invention involves preparing coating solutions for each layer, as described later, applying them in the desired layer order, and drying them. Methods for applying the coating solutions include immersion coating, spray coating, inkjet coating, roll coating, die coating, blade coating, curtain coating, wire bar coating, and ring coating. Among these, immersion coating is preferred from the viewpoint of efficiency and productivity. The support structure and each layer will be described below.

[0013] <Support> The electrophotographic photoreceptor according to the present invention has a cylindrical support, and the surface of the support is formed of at least one selected from Al and Al alloy. The surface of the support may also be subjected to hot water treatment, blast treatment, cutting treatment, etc.

[0014] (1) Crystal orientation In this invention, the notation for the crystal orientation of Al in the surface direction of the support surface, for example, the {001} orientation plane, is a representation of the Al crystal plane using Miller indices. That is, the {001} orientation plane is an all-encompassing expression of Miller indices that represent any of the crystal lattice planes (001), (010), (100), (00-1), (0-10), or (-100).

[0015] In the present invention, the surface of the support is subject to the following conditions (C3) It is characterized by satisfying the following 。 ( C3) In the surface direction of the Al texture on the surface of the support, the surface of the support is (α){001} crystal grains with orientations between -15° and +15°. (β){10¹} crystal grains with orientations of -15° or greater and less than +15°, and (γ){111} crystal grains on a plane with orientations between -15° and +15°. The surface is composed of three types of crystal grains, and on the surface of the support, the area occupied by one of the three types of crystal grains is 10% or less of the total surface area of ​​the support, and the area occupied by the remaining two types of crystal grains is 90% or more of the total surface area of ​​the support.

[0016] From the viewpoint of better obtaining the effect of the present invention in improving photosensitivity characteristics, when the above condition (C3) is satisfied, it is more preferable that the area occupied by (α), (β), or (γ) crystal grains is 5% or less of the total surface area of ​​the support, and the area occupied by the remaining two types of crystal grains is 95% or more of the total surface area of ​​the support. Furthermore, from the viewpoint of further reducing the three heterocrystalline boundaries, it is more preferable to form a small number of two types of crystal grains out of (α), (β), and (γ), and that the area occupied by (α), (β), or (γ) crystal grains is 80% or more of the total surface area of ​​the support, and even more preferable to be 90% or more. In this case, it is more preferable that the area occupied by the remaining two types of crystal grains is 20% or less of the total surface area of ​​the support, and even more preferable to be 10% or less. And, from a similar viewpoint, when the above condition (C2) is satisfied, it is more preferable that the area occupied by (α), (β), or (γ) crystal grains is 80% or more of the total surface area of ​​the support, and even more preferable to be 90% or more. In this case, it is more preferable that the area occupied by the remaining one type of crystal grain is 20% or less of the total surface area of ​​the support, and even more preferable that it is 10% or less. In such a case, the electrophotographic photoreceptor can obtain sufficient photosensitivity characteristics even when the speed of the image formation process is increased.

[0017] (Method for measuring the crystal orientation of Al crystal grains on the surface of a support) In the present invention, the crystal orientation of the Al crystal grains on the surface of the support can be measured, for example, as follows. First, the surface of the support is treated with buff polishing and an aqueous sodium hydroxide solution, and the crystal orientation of the Al crystal grains is measured at points within 20 μm of the surface of the support before treatment. The crystal orientation is preferably measured by the SEM-EBSP method. Measurements using the SEM-EBSP method employ a FE-SEM (Field Emission-Scanning Electron Microscope) equipped with an EBSP (Electron Backscatter Diffraction Pattern) detector. The SEM-EBSP method is a technique that determines the crystal orientation and crystal system at the electron beam irradiation position by analyzing the Kikuchi pattern obtained from backscattered electrons generated when an electron beam is irradiated onto the surface of a specimen. The Kikuchi pattern refers to the pattern that appears behind the electron diffraction pattern in the form of a pair of parallel lines, bands, or arrays when an electron beam strikes a crystal and is scattered and diffracted. As an FE-SEM equipped with an EBSP detector, for example, a field emission scanning electron microscope (product name: JSM-6500F, manufactured by JEOL Ltd.) can be used.

[0018] (2) Area of ​​Al crystal grains on the surface of the support In the present invention, the proportion of the area occupied by Al crystal grains having each crystal orientation can be determined as follows. As shown in Figure 2, first, positions corresponding to 1 / 8, 2 / 8, 3 / 8, 4 / 8, 5 / 8, 6 / 8, and 7 / 8 of the total length are determined axially from one end of the support. Furthermore, each position is divided into four sections by 90° in the circumferential direction. At each of the 28 points where the axial division line and the circumferential division line intersect, a 100 μm square region is set with the intersection of the axial and circumferential division lines as the center, and the crystal orientation is measured using the SEM-EBSP method described above. Subsequently, for Al crystal grains with crystal orientations (α), (β), and (γ), the area occupied by each orientation is calculated, and the obtained values ​​are measured in 10,000 μm. 2 By dividing by this, the proportion of the area occupied by Al crystal grains with each crystal orientation in each region is determined. Finally, the average value obtained from each of the 28 regions is determined as the proportion of the area occupied by (α), (β), and (γ) of the support. The area occupied by Al crystal grains with each crystal orientation can be calculated using the provided software, or it can be calculated by, for example, using the hue h of the HSV color space to define the range of (α) as 0 ≤ h < 60 and 300 ≤ h < 360, the range of (β) as 60 ≤ h < 180, and the range of (γ) as 180 ≤ h < 300, and then performing a hue mapping of the regions of Al crystal grains with each crystal orientation.

[0019] (3) Al alloy for use as a support The support in this invention may be Al or an Al alloy. Generally, for electrophotographic photoreceptors, wrought Al alloys such as the JIS designation 6000 series, 5000 series, and 3000 series are used as supports. Among these, from the viewpoint of controlling the crystal orientation, it is preferable that the Al alloy forming the surface of the support contains 0.2% to 0.6% by mass of Si and 0.45% to 0.9% by mass of Mg. As such an Al alloy, it is preferable to use a 6000 series Al alloy, for example, JIS designated A6063 alloy. Specifically, JIS designated A6063 alloy is an Al alloy containing 0.20% to 0.6% by mass of Si, 0.35% or less by mass of Fe, 0.10% or less by mass of Cu, 0.1% or less by mass of Mn, 0.45% to 0.9% by mass of Mg, 0.10% or less by mass of Cr, 0.10% or less by mass of Zn, and 0.10% or less by mass of Ti. In addition, it is preferable that the Al alloy forming the surface of the support contains 0.45% to 6.0% by mass of Mg. As such an Al alloy, it is preferable to use a 5000 series Al alloy. In addition, the Al alloy forming the surface of the support preferably contains 0.05% to 0.20% by mass of Cu and 1.0% to 1.5% by mass of Mn. As such an Al alloy, it is preferable to use a 3000 series Al alloy, for example, JIS designated A3003 alloy. Specifically, JIS designated A3003 alloy is an Al alloy containing 0.6% by mass or less of Si, 0.7% by mass or less of Fe, 0.05% to 0.20% by mass of Cu, 1.0% to 1.5% by mass of Mn, and 0.10% by mass or less of Zn.

[0020] (4) Method for manufacturing the support The method for manufacturing the support is not particularly limited, as long as it is a method that can manufacture a support that satisfies the requirements of the present invention. One example of a method for manufacturing a support is a method that includes the following four steps: • The first step involves preparing a specific aluminum alloy and performing hot extrusion to obtain a molded body. • The second step involves cold drawing of the molded body obtained in the first step. • The third step involves annealing after the second step. • The fourth step involves machining the surface after annealing. When controlling crystal orientation by annealing, it is possible to control the crystal orientation by adjusting the heating rate, annealing temperature, maintenance time, and cooling rate.

[0021] In particular, by setting the annealing temperature to 405°C or higher and 450°C or lower, recrystallization occurs such that crystal grains with (β) and (α) orientations appear on the surface. Furthermore, by setting the annealing temperature to 405°C or higher and 450°C or lower, and the cooling rate to 6°C / min or higher and 20°C / min or lower, the proportion of the surface area occupied by crystal grains with (β) orientation decreases, and the proportion of the surface area occupied by crystal grains with (α) orientation increases. In addition, by setting the cooling rate to 5°C / min or higher until the temperature of the support reaches 150°C, the appearance of Al crystal grains with (α) crystal orientation on the surface is suppressed, and Al crystal grains with (γ) crystal orientation on the surface becomes more likely to appear. Furthermore, the proportion of each crystal grain can also be controlled by the heating rate and maintenance time, and it is preferable to set the heating rate to 40°C / min or less and the maintenance time to 2.5 hours or less. Furthermore, since thermal history is important in controlling the crystal orientation, it is preferable to use materials that have undergone the above-mentioned hot extrusion and cold drawing processes, and then be annealed.

[0022] In the method for manufacturing the support of this embodiment, other steps may be included as needed before, after, between, or during each of the above-described steps for manufacturing the support. For example, processing steps such as cutting for dimensional adjustment, chamfering / spigot formation, mirror finishing / roughening, honing, blasting, and grinding may be performed as needed. Generally, the rotation axis of an electrophotographic photoreceptor is secured by fitting flange members to both ends of a cylindrical support and attaching the rotation axis to these flange members. Generally, the inner diameter dimensions of both ends of the support are set to approximately H8 of the fit tolerance in JIS B 0401-1999. Furthermore, while a smaller surface roughness is preferable from the standpoint of fit tolerance, due to manufacturing cost considerations, the arithmetic mean roughness Ra of both ends of the support is set to 1.6 μm or less and the maximum height Rz to 6.3 μm or less (or above the old JIS finish symbol ▽▽▽) in JIS B 0601-2001. If cutting oil or dust is adhering to the surface of the support, cleaning may be performed. A known method for cleaning a support includes a degreasing step to remove oil and other foreign matter adhering to the surface of the support, a rinsing step to wash away the degreasing agent, and a drying step to dry any remaining water on the support and complete the cleaning process. In the degreasing and cleaning process, the support material is immersed in a cleaning solution containing a degreasing agent such as a surfactant or alkaline electrolyzed water. Using ultrasound and increasing the temperature of the cleaning solution are effective in enhancing the degreasing and cleaning ability. The ultrasonic frequency is preferably between 10 kHz and 100 kHz for optimal effectiveness. The temperature is preferably between 30°C and 60°C for optimal effectiveness. In the rinsing process, the support is immersed in the rinsing solution. The rinsing solution can be tap water or distilled water, but distilled water is preferred. Using ultrasound and increasing the temperature of the rinsing solution are effective in improving the rinsing cleaning ability. The ultrasonic frequency is preferably between 10 kHz and 1 MHz for optimal effectiveness. The temperature is preferably between 30°C and 60°C for optimal effectiveness. There may be one rinsing tank or multiple rinsing tanks. Using a shower when removing the support after immersion further enhances the rinsing effect. While any drying method, such as hot air drying, vacuum drying, or hot water drying, is effective for the drying process, pull-up drying with warm pure water is preferred to reduce dust. The temperature of the warm pure water should be between 30°C and 99°C.

[0023] <Underlayer> The undercoat layer in the present invention contains at least one compound selected from the group consisting of the compound represented by formula (A1), the compound represented by formula (A2), the compound represented by formula (A3), the compound represented by formula (A4), and the compound represented by formula (A5), directly above the support. Tables 1-1 and 1-2 show specific examples of compounds represented by formula (A1) above. Table 2 shows specific examples of compounds represented by formula (A2) above. Table 3 shows specific examples of compounds represented by formula (A3) above. Table 4 shows specific examples of compounds represented by formula (A4) above. Table 5 shows specific examples of compounds represented by formula (A5) above. These compounds may be used individually or in combination. The undercoat layer preferably contains a resin. Alternatively, the undercoat layer may be formed as a cured film by polymerizing a composition containing a monomer having polymerizable functional groups. The resin may include polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, epoxy resin, melamine resin, polyurethane resin, phenolic resin, polyvinylphenol resin, alkyd resin, polyvinyl alcohol resin, polyethylene oxide resin, polypropylene oxide resin, polyamide resin, polyamic acid resin, polyimide resin, polyamideimide resin, cellulose resin, and the like. Polymerizable functional groups found in monomers possessing polymerizable functional groups include isocyanate groups, blocked isocyanate groups, methylol groups, alkylated methylol groups, epoxy groups, metal alkoxide groups, hydroxyl groups, amino groups, carboxyl groups, thiol groups, carboxylic acid anhydride groups, and carbon-carbon double bond groups. Furthermore, the undercoat layer may contain metal oxides, metals, conductive polymers, etc., for the purpose of improving electrical properties. 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. Furthermore, the underlayer may contain additional additives. The thickness of the undercoat layer is preferably 0.1 μm or more and 50 μm or less, and more preferably 0.3 μm or more and 25 μm or less. The undercoat can be formed by preparing an undercoat coating solution containing the above-mentioned materials and solvents, forming a coating film, and then drying and / or curing it. 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.

[0024] [Table 1-1]

[0025] [Table 1-2]

[0026] [Table 2]

[0027] [Table 3]

[0028] [Table 4]

[0029] [Table 5]

[0030] <Photosensitive layer> The photosensitive layers of electrophotographic photoreceptors are mainly classified into (1) multilayer photosensitive layers and (2) single-layer photosensitive layers. (1) A multilayer photosensitive layer has a charge generating layer containing a charge generating material and a charge transport layer containing a charge transport material. (2) A single-layer photosensitive layer has a photosensitive layer containing both a charge generating material and a charge transport material.

[0031] (1) Stacked photosensitive layer The stacked photosensitive layer has a charge generation layer and a charge transport layer. (1-1) Charge generation layer The charge generation layer preferably contains a charge generation material and a resin. Examples of charge-generating materials include azo pigments, perylene pigments, polycyclic quinone pigments, indigo pigments, and phthalocyanine pigments. Among these, azo pigments and phthalocyanine pigments are preferred. Among phthalocyanine pigments, oxytitanium phthalocyanine pigments, chlorogallium phthalocyanine pigments, and hydroxygallium phthalocyanine pigments are preferred. The content of the charge generating material in the charge generating layer is preferably 40% to 85% by mass, and more preferably 60% to 80% by mass, relative to the total mass of the charge generating layer. Examples of resins include polyester resin, polycarbonate resin, polyvinyl acetal resin, polyvinyl butyral resin, acrylic resin, silicone resin, epoxy resin, melamine resin, polyurethane resin, phenolic resin, polyvinyl alcohol resin, cellulose resin, polystyrene resin, polyvinyl acetate resin, and polyvinyl chloride resin. Among these, polyvinyl butyral resin is more preferred. Furthermore, the charge generation layer may contain additives such as antioxidants and ultraviolet absorbers. Specifically, these include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, and benzophenone compounds. The thickness of the charge generation layer is preferably 0.1 μm or more and 1 μm or less, and more preferably 0.15 μm or more and 0.4 μm or less. The charge generation layer can be formed by preparing a coating solution for the charge generation layer containing the above-mentioned materials and solvents, forming a coating film, and drying it. 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.

[0032] (1-2) Charge transport layer The charge transport layer preferably contains a charge transport material and a resin. Examples of charge transport materials include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having groups derived from these substances. Among these, triarylamine compounds and benzidine compounds are preferred. The content of the charge transport material in the charge transport layer is preferably 25% to 70% by mass, and more preferably 30% to 55% by mass, relative to the total mass of the charge transport layer. Examples of resins include polyester resin, polycarbonate resin, acrylic resin, and polystyrene resin. Among these, polycarbonate resin and polyester resin are preferred. Polyarylate resin is particularly preferred among polyester resins. The content ratio (mass ratio) of the charge transport material to the resin is preferably 4:10 to 20:10, and more preferably 5:10 to 12:10. Furthermore, the charge transport layer may contain additives such as antioxidants, ultraviolet absorbers, plasticizers, leveling agents, lubrication agents, and wear resistance enhancers. Specifically, examples include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane-modified resins, silicone oils, fluororesin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, and boron nitride particles. The thickness of the charge transport layer is preferably 5 μm to 50 μm, more preferably 8 μm to 40 μm, and particularly preferably 10 μm to 30 μm. The charge transport layer can be formed by preparing a coating solution for the charge transport layer containing the above-mentioned materials and solvents, forming a coating film, and drying it. 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.

[0033] (2) Single-layer photosensitive layer A single-layer photosensitive layer can be formed by preparing a coating solution for a photosensitive layer containing a charge generating substance, a charge transporting substance, a resin, and a solvent, forming this coating film on an undercoat layer, and drying it. The charge generating substance, charge transporting substance, and resin are the same as the examples of materials in "(1) Multilayer Photosensitive Layer" above.

[0034] <Protective layer> In this invention, a protective layer may be provided on the photosensitive layer. Providing a protective layer can improve durability. The protective layer preferably contains conductive particles and / or charge transport material and a resin. Examples of conductive particles include metal oxide particles such as titanium oxide, zinc oxide, tin oxide, and indium oxide. Examples of charge transport materials include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having groups derived from these substances. Among these, triarylamine compounds and benzidine compounds are preferred. Examples of resins include polyester resin, acrylic resin, phenoxy resin, polycarbonate resin, polystyrene resin, phenolic resin, melamine resin, and epoxy resin. Among these, polycarbonate resin, polyester resin, and acrylic resin are preferred. Furthermore, the protective layer may be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group. Examples of reactions in this process include thermal polymerization, photopolymerization, and radiation polymerization. Examples of polymerizable functional groups in monomers having a polymerizable functional group include acryloyl groups and methacryloyl groups. Materials with charge transport ability may be used as monomers having a polymerizable functional group. The protective layer may contain additives such as antioxidants, UV absorbers, plasticizers, leveling agents, lubrication agents, and wear resistance enhancers. Specifically, examples include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane-modified resins, silicone oils, fluororesin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, and boron nitride particles. The thickness of the protective layer is preferably 0.5 μm to 10 μm, and more preferably 1 μm to 7 μm. The protective layer can be formed by preparing a protective coating solution containing the above-mentioned materials and solvents, forming a coating film, and then drying and / or curing it. Examples of solvents used in the coating solution include alcohol-based solvents, ketone-based solvents, ether-based solvents, sulfoxide-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents.

[0035] [Process cartridges, electrophotographic equipment] The process cartridge according to the present invention is characterized by integrally supporting the electrophotographic photoreceptor described above and at least one means selected from the group consisting of a charging means, a developing means, and a cleaning means, and is detachably attached to the electrophotographic apparatus body. Furthermore, the electrophotographic apparatus according to the present invention is characterized by comprising the electrophotographic photoreceptor described above, a charging means, an exposure means, a developing means, and a transfer means. Figure 3 shows an example of a schematic configuration of an electrophotographic apparatus having a process cartridge equipped with an electrophotographic photoreceptor. The cylindrical electrophotographic photoreceptor 1 is rotated around axis 2 in the direction of the arrow at a predetermined peripheral speed (process speed). The surface of the electrophotographic photoreceptor 1 is charged to a predetermined positive or negative potential by the charging means 3. Although the diagram shows a roller-type charging method using a roller-type charging member, other charging methods such as corona charging, proximity charging, and injection charging may also be used. Exposure light 4 is irradiated onto the surface of the charged electrophotographic photoreceptor 1 from an exposure means (not shown), forming an electrostatic latent image corresponding to the desired image information. The exposure light 4 is light whose intensity is modulated in accordance with the time-series electrodigital image signal of the desired image information, and is output from an image exposure means such as slit exposure or laser beam scanning exposure. The electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is developed with toner contained in the developing means 5, and a toner image is formed on the surface of the electrophotographic photoreceptor 1. The toner image formed on the surface of the electrophotographic photoreceptor 1 is transferred to a transfer material 7 by a transfer means 6. The transfer material 7 with the transferred toner image is transported to a fixing means 8, where the toner image is fixed and printed out outside the electrophotographic device. The electrophotographic apparatus may have a cleaning means 9 for removing toner and other deposits remaining on the surface of the electrophotographic photoreceptor 1 after transfer. Alternatively, a so-called cleanerless system may be used in which the deposits are removed by developing means 5 or the like, without a separate cleaning means 9. In the present invention, a process cartridge 11 can be formed by housing multiple components selected from the above-mentioned electrophotographic photoreceptor 1, charging means 3, developing means 5, and cleaning means 9 in a container and supporting them integrally. This process cartridge can then be configured to be detachably attached to the electrophotographic apparatus body. For example, it can be configured as follows: At least one selected from the charging means 3, developing means 5, and cleaning means 9 is supported integrally with the electrophotographic photoreceptor 1 to form a cartridge. This can then be made into a process cartridge 11 that is detachably attached to the electrophotographic apparatus body using guide means 12 such as rails on the electrophotographic apparatus body. The electrophotographic apparatus may have a static elimination mechanism that removes static electricity from the surface of the electrophotographic photoreceptor 1 using pre-exposure light 10 from a pre-exposure means (not shown). Furthermore, guide means 12 such as rails may be provided for attaching and detaching the process cartridge 11 according to the present invention to the electrophotographic apparatus body. The electrophotographic apparatus of the present invention is characterized by having an electrophotographic photoreceptor 1 and at least one means selected from the group consisting of a charging means 3, an exposure means, a developing means 5, and a transfer means 6. The electrophotographic photoreceptor according to the present invention can be used in laser beam printers, LED printers, photocopiers, facsimile machines, and multifunction devices thereof. [Examples]

[0036] The present invention will be described in more detail below using examples and comparative examples. The present invention is not limited in any way by the following examples unless it exceeds the gist of the invention. In the following examples, "parts" refers to mass unless otherwise specified.

[0037] <Example of support material manufacturing> The support was manufactured using the following method.

[0038] (Example of manufacturing support A1) A hot-extruded extruded tube made of JIS designated A6063 alloy was cold-drawn to obtain a drawn tube with an outer diameter of 30.8 mm, an inner diameter of 28 mm, and a length of 371 mm. Next, the drawn tube was placed in an electric furnace and heated at a rate of 5°C / min, then maintained at 450°C for 1 hour. Subsequently, the temperature was lowered at a rate of 6°C / min until the drawn tube reached 150°C, and it was removed from the electric furnace after 24 hours. By performing machining after annealing, a "support A1" was obtained with an outer diameter of 30.5 mm, a length of 370 mm, and spigot sections at both ends with an inner diameter of 28.5 mm and a depth of 20 mm. The manufacturing conditions for support A1 are shown in Table 6. Elemental analysis of the drawn tubes used revealed that they were an Al alloy containing 0.4 mass% Si, 0.3 mass% Fe, 0.06 mass% Cu, less than 0.08 mass% Mn, 0.65 mass% Mg, 0.05 mass% Cr, 0.07 mass% Zn, and 0.06 mass% Ti.

[0039] (Example of manufacturing support A6) A hot-extruded extruded tube made of JIS designated A3003 alloy was cold-drawn to obtain a drawn tube with an outer diameter of 30.8 mm, an inner diameter of 28 mm, and a length of 371 mm. Next, the drawn tube was placed in an electric furnace and heated at a rate of 40°C / min, then maintained at 435°C for 1 hour. Subsequently, the temperature was lowered at a rate of 15°C / min until the drawn tube reached 150°C, and it was removed from the electric furnace after 24 hours. By performing machining after annealing, a "support A6" with the same dimensions as support A1 was obtained. The manufacturing conditions for support A6 are shown in Table 6. Elemental analysis of the drawn tube used revealed that it was an Al alloy consisting of Si: 0.3 mass%, Fe: 0.4 mass%, Cu: 0.1 mass%, Mn: 1.2 mass%, Zn: 0.05 mass%, with the remainder being Al and impurities.

[0040] (Example of manufacturing support A7) A hot-extruded extruded tube made of a JIS-designated 5000 series alloy (Al-Mg alloy) containing 2.5% by mass of magnesium was cold-drawn to obtain a drawn tube with an outer diameter of 30.8 mm, an inner diameter of 28 mm, and a length of 371 mm. Next, the drawn tube was placed in an electric furnace and heated at a rate of 5°C / min, then maintained at 450°C for 1 hour. Subsequently, the temperature was lowered at a rate of 15°C / min until the drawn tube reached 150°C, and it was removed from the electric furnace after 24 hours. By performing machining after annealing, a "support A7" with the same dimensions as support A1 was obtained. The manufacturing conditions for support A7 are shown in Table 6. Elemental analysis of the drawn tubes used revealed that they were an Al alloy containing Si: 0.1 mass%, Fe: 0.1 mass%, Cu: 0.02 mass%, Mg: 2.5 mass%, and Zn: 0.01 mass%.

[0041] (Manufacturing examples of supports A2-A5 and A8-A44) The aluminum alloy used for the drawn tube and the annealing conditions are as shown in Table 6. Otherwise, the support was manufactured in the same manner as the manufacturing examples for support A1, A6, and A7. The obtained supports will be designated as "Support A2 to Support A5, and Support A8 to Support A44".

[0042] (Examples of manufacturing support materials C1-C13) The aluminum alloy used for the drawn tube and the annealing conditions are as shown in Table 7. Otherwise, the support was manufactured in the same manner as the manufacturing examples for support A1, A6, and A7. The obtained supports will be designated as "Support C1 to Support C13".

[0043] [Table 6]

[0044] [Table 7]

[0045] <Example of preparation of coating solution 1 for the undercoat layer> The following materials were prepared. • Exemplary compound A101: 4 parts • Polyvinyl butyral resin (product name: S-REC® BX-1, manufactured by Sekisui Chemical Co., Ltd.): 1.5 parts • Zinc(II) octoate as catalyst: 0.0005 parts These were dissolved in a mixed solvent of 100 parts dimethylacetamide and 100 parts tetrahydrofuran. To this solution, 6 parts of block isocyanate (trade name: BL3175, manufactured by Sumika Bayer) was added to prepare coating solution 1 for the undercoat layer.

[0046] <Examples of preparation of coating solutions 2-4 for the undercoat layer> The example compounds used for the undercoat layer were prepared under the conditions shown in Table 8, and under the same conditions as undercoat layer coating solution 1, undercoat layer coating solutions 2 to 4 were prepared.

[0047] [Table 8]

[0048] <Example of preparation of coating solution 5 for the undercoat layer> The following materials were prepared. • Butyral resin as a polyol resin (product name: S-REC® BM-1, manufactured by Sekisui Chemical Co., Ltd.) 7.5 parts • Blocked isocyanate resin (product name: Duranate® TPA-B80E, 80% solution, manufactured by Asahi Kasei Corporation) 20 parts These were dissolved in a mixed solvent of 45 parts methyl ethyl ketone and 85 parts 1-butanol to obtain a solution. 30 parts by mass of example compound A301 were added to the resulting mixture and mixed. Then, dispersion was carried out for 10 hours using a sand mill with 1 mmφ glass beads to obtain a dispersion. To this dispersion, 0.01 parts of silicone oil (product name: DOWSIL® SH28 PAINT ADDITIVE, manufactured by Toray Dow Corning Co., Ltd.) was added as a leveling agent. At the same time, 5.0 parts of cross-linked polymethyl methacrylate (PMMA) particles (product name: Techpolymer® SSX-103, manufactured by Sekisui Chemical Co., Ltd., average primary particle size 3.1 μm) were added as a surface roughening agent. After stirring, coating solution 5 for the undercoat layer was prepared.

[0049] <Examples of preparation of coating solutions 6-8 for the undercoat layer> The example compounds and quantities used for the undercoat layer were as shown in Table 9, and under the same conditions as undercoat layer coating solution 5, undercoat layer coating solutions 6 to 8 were prepared.

[0050] [Table 9]

[0051] <Example of preparation of coating solution 9 for the undercoat layer> Zinc oxide particles as a metal oxide (specific surface area: 19 m²) 2 / g, powder resistance: 4.7×10 6 100 parts of (Ω·cm) were mixed with 500 parts of toluene by stirring, and 0.8 parts of a silane coupling agent (compound name: N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, trade name: KBM-602, manufactured by Shin-Etsu Chemical Co., Ltd.) were added and the mixture was stirred for 6 hours. Then, the toluene was removed by distillation under reduced pressure, and the mixture was heated and dried at 130°C for 6 hours to obtain surface-treated zinc oxide particles. After that, the following materials were prepared. • 15 parts of butyral resin (product name: S-REC® BM-1, manufactured by Sekisui Chemical Co., Ltd.) as the polyol resin. • Blocked isocyanate (product name: Duranate® TPA-B80E, 80% solution, manufactured by Asahi Kasei Corporation) 15 parts These were dissolved in a mixed solution of 73.5 parts methyl ethyl ketone and 73.5 parts 1-butanol. To this solution, 30 parts of the surface-treated zinc oxide particles and 2 parts of exemplary compound A512 were added, and the mixture was dispersed for 3 hours in a sand mill apparatus using glass beads with a diameter of 0.8 mm at an atmosphere of 23 ± 3 °C to obtain a dispersion. To this dispersion, 0.01 parts of silicone oil (product name: DOWSIL® SH28 PAINT ADDITIVE, manufactured by Toray Dow Corning Silicone Co., Ltd.) was added as a leveling agent. At the same time, 5.0 parts of cross-linked polymethyl methacrylate (PMMA) particles (product name: Techpolymer® SSX-103, manufactured by Sekisui Chemical Co., Ltd., average primary particle size 3.1 μm) were added as a surface roughening agent. The coating solution 9 for the undercoat was then prepared by stirring.

[0052] <Example of preparation of coating solution 10 for the undercoat layer> The example compounds and quantities used for the undercoat layer are as shown in Table 10, and the undercoat layer coating solution 10 was prepared in the same manner as undercoat layer coating solution 9, except that the example compounds and quantities used for the undercoat layer were as shown in Table 10.

[0053] [Table 10]

[0054] <Example 1> (Support) Support A1 was used as the support material.

[0055] (Underlying layer) Next, the undercoat coating liquid 1 was applied to the support by immersion to form a coating film, and the resulting coating film was dried and heat-cured at 160°C for 30 minutes to form an undercoat layer with a thickness of 0.8 μm.

[0056] (Charge generation layer) Next, I prepared the following materials. 20 parts of hydroxygallium phthalocyanine crystals (charge-generating material) in a crystalline form exhibiting peaks at 7.4° and 28.2° of the Bragg angle 2θ±0.2° in CuKα characteristic X-ray diffraction. • 0.2 parts of the calixarene compound represented by the following formula (B), [ka] • Polyvinyl butyral (product name: S-REC® BX-1, manufactured by Sekisui Chemical Co., Ltd.) 10 units 600 parts of cyclohexanone These materials were placed in a sand mill using 1 mm diameter glass beads and dispersed for 4 hours. Subsequently, 700 parts of ethyl acetate were added to prepare a coating solution for the charge generation layer. This coating solution for the charge generation layer was applied to the undercoat layer by immersion, and the resulting coating film was dried at 80°C for 15 minutes to form a charge generation layer with a thickness of 0.17 μm.

[0057] (charge transport layer) Next, I prepared the following materials. • 90 parts of the compound represented by the following formula (C) (charge transport material) [ka] • Polycarbonate resin (product name: Yupiron® Z400, manufactured by Mitsubishi Engineering Plastics Corporation, bisphenol Z type polycarbonate) 100 parts • 0.02 parts of polycarbonate represented by the following formula (D) (viscosity-average molecular weight Mv: 20000) [ka] These were dissolved in a mixed solvent of 600 parts xylene and 200 parts dimethoxymethane to prepare a coating solution for the charge transport layer. This coating solution for the charge transport layer was applied to the charge generating layer by immersion 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. The electrophotographic photoreceptor of Example 1 was manufactured using the above procedure. The obtained electrophotographic photoreceptor is referred to as "Photoreceptor A1".

[0058] <Examples 2-44> An electrophotographic photoreceptor was manufactured in the same manner as photoreceptor A1 shown in Example 1, except that the support material was changed to the support material shown in Table 11-1. The resulting electrophotographic photoreceptors were designated as "photoreceptors A2 to A44".

[0059] <Examples 45-440> In Example 1, electrophotographic photoreceptors were manufactured by changing the support material, the coating solution used for forming the undercoat layer, and the thickness of the undercoat layer to the conditions shown in Tables 11-2 to 11-10, while otherwise being the same as for photoreceptor A1. The resulting electrophotographic photoreceptors were designated as "photoreceptors A45 to A440".

[0060] <Comparative Examples 1-130> For the photoreceptor A1 shown in Example 1, the support material, the coating solution used for forming the undercoat layer, and the thickness of the undercoat layer were changed to the conditions shown in Tables 12-1 to 12-3, and all other conditions were the same as for photoreceptor A1 to produce an electrophotographic photoreceptor. The resulting electrophotographic photoreceptors were designated as "photoreceptors C1 to C130".

[0061] Table 11-1

[0062] Table 11-2

[0063] Table 11-3

[0064] Table 11-4

[0065] Table 11-5

[0066] Table 11-6

[0067] Table 11-7

[0068] Table 11-8

[0069] Table 11-9

[0070] Table 11-10

[0071] Table 12-1

[0072] [Table 12-2]

[0073] [Table 12-3]

[0074] [Evaluation of electrophotographic photoconductors] The electrophotographic photoreceptors prepared as described above were evaluated as follows. (Measurement of the area of ​​Al crystal grains on the surface of the support) For the electrophotographic photoreceptor to be evaluated, we determined positions corresponding to 1 / 8, 2 / 8, 3 / 8, 4 / 8, 5 / 8, 6 / 8, and 7 / 8 of the total length in the axial direction from one end. Furthermore, at each of these positions, we divided the material into four sections at 90° intervals in the circumferential direction. At each of the 28 points where the axial division line and the circumferential division line intersected, we cut out 10mm square pieces so that the intersection of the axial and circumferential division lines was at the center. After removing the protective layer with an abrasive sheet, the photosensitive layer was removed using methyl ethyl ketone. Then, the support surface was exposed and polished to a mirror finish by buff polishing. Next, the sample was immersed in an aqueous sodium hydroxide solution for 1 minute to obtain a sample for crystal orientation observation. The central position of the surface of the obtained sample was observed using the SEM-EBSP method described above, and the percentage of the area occupied by Al crystal grains with each crystal orientation and the average area of ​​Al crystal grains were calculated using the method described above. The measured results are shown in Tables 13-1 to 13-10 and Tables 14-1 to 14-3.

[0075] (Evaluation of light sensitivity characteristics) A photoreceptor testing apparatus (product name: CYNTHIA59, manufactured by Gentec Co., Ltd.) was used to evaluate the photosensitivity characteristics. The exposure means and surface potential probe were positioned at 60° and 120°, respectively, relative to the center of the charger. The above photoreceptor testing apparatus was set up in a normal temperature and humidity environment (23°C / 50%RH), and the electrophotographic photoreceptor to be evaluated was placed inside the apparatus. The electrophotographic photoreceptor was rotated so that its peripheral speed was 550 mm / sec, and the conditions of the charging apparatus were set so that the average potential in the circumferential direction of the electrophotographic photoreceptor was -700V. Monochromatic light with a wavelength of 780 nm was applied to the charged electrophotographic photoreceptor at a rate of 0.30 μJ / cm². 2 The surface was irradiated with the specified energy level, and the surface potential was measured in this state. Surface potential was measured using a surface potential probe (model 6000B-8: manufactured by Trek Japan Co., Ltd.) placed 2 mm away from the electrophotographic photoreceptor, and a surface potential meter (model 344: manufactured by Trek Japan Co., Ltd.). Under these measurement conditions, the measurement spot size of the surface potential meter was approximately 10 mm in diameter. The average potential in the circumferential direction of the electrophotographic photoreceptor was calculated from the measured surface potential, and its absolute value was defined as the photosensitivity. A smaller numerical value indicates better photosensitivity characteristics. In this evaluation, the following criteria were used for judgment. AA: Less than 200.0V A: 200.0V or higher, less than 203.0V B: 203.0V or higher, less than 206.0V C: 206.0V or higher, less than 209.0V D: 209.0V or higher, less than 212.0V E:212.0V or more

[0076] [Table 13-1]

[0077] [Table 13-2]

[0078] Table 13-3

[0079] Table 13-4

[0080] Table 13-5

[0081] Table 13-6

[0082] Table 13-7

[0083] Table 13-8

[0084] Table 13-9

[0085] Table 13-10

[0086] Table 14-1

[0087] Table 14-2

[0088] [Table 14-3]

[0089] The disclosure of embodiments according to the present invention includes the following configurations. (Composition 1) An electrophotographic photoreceptor having a cylindrical support, an undercoat formed directly above the support, and a photosensitive layer formed on the undercoat, The undercoat contains at least one compound selected from the group consisting of the compound represented by formula (A1), the compound represented by formula (A2), the compound represented by formula (A3), the compound represented by formula (A4), and the compound represented by formula (A5). The surface of the support is formed of Al and / or an Al alloy. An electrophotographic photoreceptor characterized in that the surface of the support satisfies any one of the following conditions (C1) to (C3). (C1) In the surface direction of the Al texture of the surface of the support, the surface of the support is (α){001} crystal grains with orientations between -15° and +15°. (β){10¹} crystal grains with orientations of -15° or greater and less than +15°, and (γ){111} crystal grains on a plane with orientations between -15° and +15°. It is a surface consisting of one type of crystal grain selected from the group consisting of the following: (C2) In the surface direction of the Al texture of the surface of the support, the surface of the support is (α){001} crystal grains with orientations between -15° and +15°. (β){10¹} crystal grains with orientations of -15° or greater and less than +15°, and (γ){111} crystal grains on a plane with orientations between -15° and +15°. It is a surface consisting of two types of crystal grains selected from the group consisting of the following: (C3) In the surface direction of the Al texture of the surface of the support, the surface of the support is (α){001} crystal grains with orientations between -15° and +15°. (β){10¹} crystal grains with orientations of -15° or greater and less than +15°, and (γ){111} crystal grains on a plane with orientations between -15° and +15°. The surface is composed of three types of crystal grains, and on the surface of the support, the area occupied by one of the three types of crystal grains is 10% or less of the total surface area of ​​the support, and the area occupied by the remaining two types of crystal grains is 90% or more of the total surface area of ​​the support. [ka] [ka] [ka] [ka] [ka] (In formulas (A1) and (A2), R 101 ~R 106 , R 201 ~R 210 Each of these independently represents a hydrogen atom, a cyano group, a nitro group, a halogen atom, an alkoxycarbonyl group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heterocyclic group. One of the CH2 groups of the alkyl group may be substituted with O or S, and one of the CH groups of the alkyl group may be substituted with N. The substituent of the substituted alkyl group is a group selected from the group consisting of alkyl groups, hydroxyl groups, aryl groups, alkoxycarbonyl groups, and halogen atoms. The substituent of the substituted aryl group is a group selected from the group consisting of halogen atoms, nitro groups, cyano groups, alkyl groups, alkoxy groups, and halogen-substituted alkyl groups. R in formula (A3) 301 ~R 308 and R in formula (A4) 401 ~R 408each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, or a substituted or unsubstituted alkoxycarbonyl group having 1 to 10 carbon atoms. Alternatively, R 301 and R 302 , R 302 and R 303 , R 303 and R 304 , R 305 and R 306 , R 306 and R 307 , R 307 and R 308 , R 401 and R 402 , R 402 and R 403 , R 403 and R 404 , R 405 and R 406 , R 406 and R 407 , and R 407 and R 408 may each independently be bonded to each other to form a ring. In formula (A5), n1 and n2 each independently represent an integer of 0 to 4, provided that n1 and n2 do not represent 0 at the same time. R 501 and R 502 may or may not be present. R 501 and R 502 each independently represent an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an aryl group having 6 to 30 carbon atoms.) (Configuration 2) the surface of the support satisfies the condition (C3), on the surface of the support, the area ratio occupied by one of the three types of crystal grains is 5% or less relative to the total area of the surface of the support, and the area ratio occupied by the remaining two types of crystal grains is 95% or more relative to the total area of the surface of the support, The electrophotographic photoreceptor according to Configuration 1. (Configuration 3) The surface of the support satisfies the condition (C3), an area proportion of one crystal grain among the three crystal grains is 80% or more of the total area of the surface of the support, and an area proportion of the remaining two crystal grains is 20% or less of the total area of the surface of the support, The electrophotographic photoreceptor according to Configuration 1 or 2. (Configuration 4) The surface of the support satisfies the condition (C2), an area proportion of one crystal grain among the two crystal grains is 80% or more of the total area of the surface of the support, and an area proportion of the remaining one crystal grain is 20% or less of the total area of the surface of the support, The electrophotographic photoreceptor according to Configuration 1. (Configuration 5) The electrophotographic photoreceptor according to any one of Configurations 1 to 4, wherein the undercoat layer contains a compound represented by Formula (A5). (Configuration 6) The electrophotographic photoreceptor according to any one of Configurations 1 to 5, wherein the support is an Al alloy containing 0.2 mass% to 0.6 mass% of Si, and 0.45 mass% to 0.9 mass% of Mg. (Configuration 7) The electrophotographic photoreceptor according to any one of Configurations 1 to 5, wherein the support is an Al alloy containing 0.45 mass% to 6.0 mass% of Mg. (Configuration 8) The electrophotographic photoreceptor according to any one of Configurations 1 to 7, wherein the support is an Al alloy containing 0.05 mass% to 0.20 mass% of Cu, and 1.0 mass% to 1.5 mass% of Mn. (Configuration 9) A process cartridge that integrally supports the electrophotographic photoreceptor according to any one of Configurations 1 to 8 and at least one unit selected from the group consisting of a charging unit, a developing unit, and a cleaning unit, and is detachably attachable to a main body of an electrophotographic apparatus. (Configuration 10) An electrophotographic apparatus comprising the electrophotographic photoreceptor according to any one of Configurations 1 to 8, and a charging unit, an exposing unit, a developing unit, and a transferring unit. [Explanation of Symbols]

[0090] 1. Electrophotographic photoreceptor 2 axes 3. Charging means 4 Exposure light 5. Developing means 6. Transfer means 7 Transfer material 8 Fixing means 9. Cleaning methods 10 Pre-exposure light 11 Process Cartridges 12 Guidance methods

Claims

1. An electrophotographic photoreceptor having a cylindrical support, an undercoat formed directly above the support, and a photosensitive layer formed on the undercoat, The undercoat contains at least one compound selected from the group consisting of the compound represented by formula (A1), the compound represented by formula (A2), the compound represented by formula (A3), the compound represented by formula (A4), and the compound represented by formula (A5). The surface of the support is formed of Al and / or an Al alloy. The surface of the support satisfies the following condition (C3): An electrophotographic photoreceptor characterized by the following features. (C3) In the surface direction of the Al texture of the surface of the support, the surface of the support is (α) {001} crystal grains on a plane with an orientation of -15° or greater and less than +15°, (β) Crystal grains with a plane of orientation -15° or greater and less than +15° in the {10¹} direction, and (γ) {111} crystal grains on planes with orientations of -15° or greater and less than +15°. The surface is composed of three types of crystal grains, and on the surface of the support, the area occupied by one of the three types of crystal grains is 10% or less of the total surface area of ​​the support, and the area occupied by the remaining two types of crystal grains is 90% or more of the total surface area of ​​the support. 【Chemistry 1】 【Chemistry 2】 【Transformation 3】 【Chemistry 4】 【Transformation 5】 (R in formula (A1)) １０１ ~R １０６ , and R in formula (A2) ２０１ ~R ２１０ Each of these independently represents a hydrogen atom, a cyano group, a nitro group, a halogen atom, an alkoxycarbonyl group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heterocyclic group. The CH of the alkyl group ２ One of the groups may be substituted with O or S, and one of the CH groups of the alkyl group may be substituted with N. The substituent of the substituted alkyl group is a group selected from the group consisting of alkyl groups, hydroxyl groups, aryl groups, alkoxycarbonyl groups, and halogen atoms. The substituent of the substituted aryl group is a group selected from the group consisting of halogen atoms, nitro groups, cyano groups, alkyl groups, alkoxy groups, and halogen-substituted alkyl groups. In formula (A3), R ３０１ to R ３０８ , and R in formula (A4) ４０１ to R ４０８ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, or a substituted or unsubstituted alkoxycarbonyl group having 1 to 10 carbon atoms. Alternatively, R ３０１ and R ３０２ , R ３０２ and R ３０３ , R ３０３ and R ３０４ , R ３０５ and R ３０６ , R ３０６ and R ３０７ , R ３０７ and R ３０８ , R ４０１ and R ４０２ , R ４０２ and R ４０３ , R ４０３ and R ４０４ , R ４０５ and R ４０６ , R ４０６ and R ４０７ , and R ４０７ and R ４０８ may each independently be linked together to form a ring. In equation (A5), n1 and n2 each independently represent integers between 0 and 4 (inclusive). However, n1 and n2 cannot both be 0 at the same time. ５０１ and R ５０２ It is optional, but R ５０１ and R ５０２ Each of these independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an aryl group having 6 to 30 carbon atoms.

2. The electrophotographic photoreceptor according to Claim 1, wherein, on the surface of the support, the area occupied by one of the three types of crystal grains is 5% or less of the total surface area of ​​the support, and the area occupied by the remaining two types of crystal grains is 95% or more of the total surface area of ​​the support.

3. The electrophotographic photoreceptor according to Claim 1, wherein the area occupied by one of the three types of crystal grains is 80% or more of the total surface area of ​​the support, and the area occupied by the remaining two types of crystal grains is 20% or less of the total surface area of ​​the support.

4. The electrophotographic photoreceptor according to claim 1, wherein the undercoat layer contains a compound represented by formula (A5).

5. The electrophotographic photoreceptor according to claim 1, wherein the support is an Al alloy containing 0.2% by mass or more and 0.6% by mass or less of Si, and 0.45% by mass or more and 0.9% by mass or less of Mg.

6. The electrophotographic photoreceptor according to claim 1, wherein the support is an Al alloy containing 0.45% by mass or more and 6.0% by mass or less of Mg.

7. The electrophotographic photoreceptor according to claim 1, wherein the support is an Al alloy containing 0.05% by mass or more and 0.20% by mass or less of Cu, and 1.0% by mass or more and 1.5% by mass or less of Mn.

8. An electrophotographic photoreceptor according to any one of claims 1 to 7, At least one means selected from the group consisting of a charging means, a developing means, and a cleaning means, A process cartridge that provides integrated support and is detachably attached to the main body of an electrophotographic device.

9. An electrophotographic photoreceptor according to any one of claims 1 to 7, and an electrophotographic apparatus having a charging means, an exposure means, a developing means and a transfer means.

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