Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

Abstract

This invention relates to an electrophotographic photosensitive element, a processing cartridge, and an electrophotographic apparatus. An electrophotographic photosensitive element is provided, characterized in that, in a graph obtained by measuring an EV curve and having a horizontal axis representing I and a vertical axis representing V, when I = 0.500 [μJ / cm²]... 2 V at time ] by V r [V] represents I = 0.000~0.030 [μJ / cm] 2 Within the range of S = I·(V - V) r S[V·μJ / cm] represents 2 The maximum value of ] is determined by S max [V·μJ / cm 2 [This indicates that] I = 0.000–0.010 [μJ / cm²] 2 The approximate straight line within the range of ] and I = 0.490~0.500 [μJ / cm 2 The amount of light I on the horizontal axis at the intersection of approximately straight lines within the range of ] i [μJ / cm 2 [and the potential V on the vertical axis] i The product of [V] is given by S i =I i ·(V i -V r )[V·μJ / cm 2 When represented by ], AR = S i / S max S represents i With S max The ratio satisfies AR ≤ 0.10.

Description

Technical Field

[0001] The present invention relates to an electrophotographic photosensitive element, as well as a processing box and an electrophotographic apparatus using the electrophotographic photosensitive element. Background Technology

[0002] Electrophotographic photosensitive components (hereinafter sometimes simply referred to as "photosensitive components") used in electrophotographic equipment are typically obtained by forming various layers, such as a photosensitive layer, on a support. Furthermore, from the viewpoint of low cost and high productivity, organic photosensitive components, in which the main component of the layers to be formed on the support is resin, have gained widespread use as electrophotographic photosensitive components in recent years. In particular, organic photosensitive components with a laminated photosensitive layer have become mainstream due to their advantages in terms of high sensitivity and versatility in material design. A laminated organic photosensitive component has a structure in which a charge-generating layer containing charge-generating substances such as photoconductive dyes or photoconductive pigments is laminated with a charge-transporting layer containing charge-transporting substances such as photoconductive polymers or photoconductive low-molecular-weight compounds. With recent technological advancements, rapid progress has been made in increasing the speed of electrophotographic processing, thus requiring photosensitive components with high sensitivity characteristics that sufficiently reduce their surface potential even during short exposure times. In particular, the exposure amount I of the photosensitive component... exp [μJ / cm 2 The absolute value of the obtained surface potential V exp In the relationship between [V] (hereinafter referred to as the "EV curve"), it is linear, that is, it remains at I even in the high-intensity region. exp The degree of slope near 0 is important.

[0003] Meanwhile, the electrophotographic processing related to the photosensitive component mainly consists of four steps: charging, exposure, development, and transfer, with additional steps such as cleaning and pre-exposure added as needed. Among these, the exposure step, which controls the charge distribution of the photosensitive component to achieve the desired potential distribution on its surface, is crucial for forming an electrostatic latent image.

[0004] There are two methods for controlling the image density of electrophotographic equipment during the exposure process: analog grayscale systems and digital grayscale systems. An analog grayscale system involves adjusting the exposure amount to set the average potential of the photosensitive element surface to a desired value, and controlling the amount of toner developed on the photosensitive element during the development process to represent the grayscale density from the toner-undeveloped area (so-called solid white) to the toner-maximally-developed area (so-called solid black). On the other hand, in a digital grayscale system, the amount of light emitted is constantly fixed at its maximum value, and the surface potential of the photosensitive element in the illuminated area is minimized, thereby maximizing the toner development amount in the illuminated area. That is, in the case of a digital grayscale system, the interior of a single-point area illuminated by light is always solid black. The grayscale density is represented by controlling the area ratio of the solid black points.

[0005] Semiconductor lasers, used in recent years' electrophotographic equipment, have small spot diameters, thus digital grayscale systems have become mainstream. However, semiconductor lasers typically have a bell-shaped light distribution, and their 1 / e 2 The diameter typically ranges from tens of μm to 100 μm. Typical resolutions for electrophotographic equipment are 300 dpi, 600 dpi, and 1200 dpi, and the single-point length is almost the same in all cases, namely 84 μm, 42 μm, and 21 μm. Therefore, in practice, digital grayscale and analog grayscale exist as a mixture, and their ratio is affected by the line count during image formation. As the line count decreases, the image frequency decreases and the spot diameter becomes relatively small, so the mixture becomes closer to digital grayscale. Conversely, as the line count increases, the image frequency increases and the spot diameter becomes relatively large, so the mixture becomes closer to analog grayscale.

[0006] As described above, in order to obtain satisfactory grayscale characteristics in the aforementioned electrophotographic apparatus where digital grayscale and analog grayscale exist as a mixture, it is necessary to set the exposure amount to achieve a balance between digital grayscale and analog grayscale during electrostatic latent image formation. In this case, it is difficult to set such an exposure amount when the characteristics of the EV curve of the aforementioned stacked organic photosensitive element are not satisfied. For example, when using a laser with a small spot diameter to meet the requirements of improving the speed and image quality of the electrophotographic apparatus, digital grayscale characteristics are enhanced. On the other hand, analog grayscale characteristics tend to deteriorate at high line count halftones.

[0007] Japanese Patent Application Publication No. 2002-131953 describes a technique for achieving both high sensitivity and high resolution by including two specific phthalocyanine pigments.

[0008] Japanese Patent Publication No. 2005-526267 describes a technique for controlling the sensitivity of a photosensitive element by using both type I and type IV titanium phthalocyanine in the charge generation layer.

[0009] Japanese Patent Application Publication No. 2003-195577 discloses an electrophotographic device that provides images with excellent resolution and gradation and can output high-quality images without high-speed scanning of the image by comprising an electrophotographic photosensitive element configured to satisfy specific potential characteristics, a charging unit configured to satisfy specific charging potential, an exposure unit (image exposure unit) configured to form a digital latent image, and a developing unit configured to perform contact development and satisfy specific development contrast potential. Summary of the Invention

[0010] Based on research conducted by the inventors, it was found that the electrophotographic photosensitive components and electrophotographic devices described in Japanese Patent Application Publication No. 2002-131953, Japanese Patent Translation Publication No. 2005-526267, and Japanese Patent Application Publication No. 2003-195577 are not sufficiently optimized in terms of EV curves. That is, improving analog grayscale characteristics at high line count halftones while maintaining high-quality digital grayscale by using lasers with small spot diameters has always been a challenge.

[0011] Therefore, the object of the present invention is to provide an electrophotographic photosensitive element that improves the analog grayscale characteristics under high line count halftone while maintaining high-quality digital grayscale, as well as a processing box and an electrophotographic device using the electrophotographic photosensitive element respectively.

[0012] The above-mentioned objective is achieved through the following invention. Specifically, an electrophotographic photosensitive component is provided, comprising: a support, a charge generating layer formed on the support, and a charge transport layer formed on the charge generating layer, wherein the electrophotographic photosensitive component is an organic photosensitive component, and wherein it is obtained at a temperature of 23.5 [°C] and a relative humidity of 50 [%RH] according to the following <Method for Measuring EV Curves> and has an expression representing I. exp The horizontal axis and represent V exp In the graph of the vertical axis, when I in the graph exp =0.500 [μJ / cm 2 V at that time exp By V r [V] represents I in the diagram. exp =0.000~0.030 [μJ / cm] 2 Within the range of S=I exp ·(V exp -V r S[V·μJ / cm] represents2 The maximum value of ] is determined by S max [V·μJ / cm 2 [Represents, in the diagram, I] exp =0.000~0.010 [μJ / cm] 2 Approximate straight line within the range of I exp =0.490~0.500 [μJ / cm 2 The amount of light I on the horizontal axis at the intersection of approximately straight lines within the range of ] i [μJ / cm 2 [and the potential V on the vertical axis] i The product of [V] is given by S i =I i ·(V i -V r )[V·μJ / cm 2 ] indicates, and S i With S max The value of the ratio S i / S max When represented by AR, AR satisfies AR≤0.10.

[0013] <Methods for Measuring EV Curves>

[0014] (1): Set the surface potential of the electrophotographic photosensitive element to 0 [V].

[0015] (2): The electrophotographic photosensitive element is charged for 0.005 seconds so that the absolute value of the initial surface potential of the electrophotographic photosensitive element becomes V0[V].

[0016] (3): 0.02 seconds after the start of charging, the charged electrophotographic photosensitive component is continuously exposed to an atmosphere with a wavelength of 805 nm and an intensity of 25 mW / cm². 2 The light is emitted in seconds, thus achieving an exposure of I. exp [μJ / cm 2 ].

[0017] (4): 0.06 seconds after the start of charging, the absolute value of the surface potential of the electrophotographic photosensitive element after exposure is measured and determined by V. exp [V] indicates.

[0018] (5): At 0.001 [μJ / cm 2 The interval of I will exp From 0.000 [μJ / cm 2 [Changed to 1.000 [μJ / cm]] 2 Simultaneously repeat operations (1) to (4) to obtain the corresponding I. exp V exp [V].

[0019] (6): In operations (1) to (5), in operation (3) t=0 and I exp =0.000[μJ / cm 2 V at that time exp [V] is specifically referred to as the electric potential V. d [V], and set V0[V] in operation (2) so that V d [V] takes the value of 300V.

[0020] According to the present invention, an electrophotographic photosensitive element that improves analog grayscale while maintaining satisfactory digital grayscale can be provided, as well as a processing box and an electrophotographic device using the electrophotographic photosensitive element respectively.

[0021] Further features of the invention will become apparent from the following description of exemplary embodiments, with reference to the accompanying drawings. Attached Figure Description

[0022] Figure 1 This is an illustration of an example of the layer structure of the electrophotographic photosensitive component according to the present invention.

[0023] Figure 2 This is an illustration of an example of the schematic configuration of an electrophotographic device having a processing box including an electrophotographic photosensitive element and a charging unit.

[0024] Figure 3A , Figure 3B and Figure 3C A graph illustrating the relationship between analog grayscale and digital grayscale in the EV curve of a prior art photosensitive element.

[0025] Figure 4 A graph illustrating the relationship between analog grayscale and digital grayscale in the EV curve of this invention.

[0026] Figure 5 A conceptual diagram illustrating the method for defining the EV curve used in the evaluation of this invention.

[0027] Figure 6 A conceptual diagram of a method for calculating the characteristics used in the evaluation of this invention. Detailed Implementation

[0028] The present invention will now be described in detail by way of exemplary embodiments.

[0029] This invention relates to an electrophotographic photosensitive component, which is an organic photosensitive component comprising a support and an organic photosensitive layer formed on the support. The organic photosensitive layer includes a charge generating layer and a charge transport layer formed on the charge generating layer. The component is obtained according to the <Method for Measuring EV Curves> at a temperature of 23.5°C and a relative humidity of 50%RH and has a value representing I. exp The horizontal axis and represent V exp In the graph of the vertical axis, when I in the graph exp =0.500 [μJ / cm 2 V at that time exp By V r [V] represents I in the diagram. exp =0.000~0.030 [μJ / cm] 2 Within the range of S=I exp ·(V exp -V r S[V·μJ / cm] represents 2 The maximum value of ] is determined by S max [V·μJ / cm 2 ] indicates, and in the figure I exp =0.000~0.010 [μJ / cm] 2 Approximate straight line within the range of I exp =0.490~0.500 [μJ / cm 2 The amount of light I on the horizontal axis at the intersection of approximately straight lines within the range of ] i [μJ / cm 2 [and the potential V on the vertical axis] i The product of [V] is given by S i =I i ·(V i -V r )[V·μJ / cm 2 When ] is represented, in S i With S max The value of the ratio S i / S max In the case represented by AR, AR satisfies AR≤0.10.

[0030] <Methods for Measuring EV Curves>

[0031] (1): Set the surface potential of the electrophotographic photosensitive element to 0 [V].

[0032] (2): The electrophotographic photosensitive element is charged for 0.005 seconds so that the absolute value of the initial surface potential of the electrophotographic photosensitive element becomes V0[V].

[0033] (3): 0.02 seconds after the start of charging, the charged electrophotographic photosensitive component is continuously exposed to an atmosphere with a wavelength of 805 nm and an intensity of 25 mW / cm². 2 The light is emitted in seconds, thus achieving an exposure of I. exp [μJ / cm 2 ].

[0034] (4): 0.06 seconds after the start of charging, the absolute value of the surface potential of the electrophotographic photosensitive element after exposure is measured and determined by V. exp [V] indicates.

[0035] (5): At 0.001 [μJ / cm 2 The interval of I will exp From 0.000 [μJ / cm 2 [Changed to 1.000 [μJ / cm]] 2 Simultaneously repeat operations (1) to (4) to obtain the corresponding I. exp V exp .

[0036] (6): In operations (1) to (5), in operation (3) t=0 and I exp =0.000[μJ / cm 2 V at that time exp [V] is specifically referred to as the electric potential V. d [V], and set V0[V] in operation (2) so that V d [V] takes the value of 300V.

[0037] The present invention also relates to a processing box comprising: the aforementioned electrophotographic photosensitive component, and at least one unit selected from the group consisting of a charging unit, a developing unit, and a cleaning unit, wherein the processing box integrally supports the electrophotographic photosensitive component and the at least one unit, and the processing box is detachably mounted to the body of the electrophotographic device.

[0038] The present invention also relates to an electrophotographic device, comprising: the aforementioned electrophotographic photosensitive component, charging unit, image exposure unit, developing unit, and transfer unit.

[0039] The inventors speculate as follows why such an electrophotographic photosensitive component can improve the analog grayscale characteristics under high line count halftone while maintaining high-quality digital grayscale.

[0040] exist Figure 3A , Figure 3B and Figure 3C The image shows the barter relationship between analog and digital grayscale in the EV curve of a prior art photosensitive element.

[0041] To improve digital grayscale, a single pixel needs to be dark and stable. Therefore, it is appropriate to choose... Figure 3A The highlight amount in region (b) of the EV curve is taken as the image exposure. In this case, such as Figure 3A As shown, the absolute value of the slope of the EV curve is small relative to the change in light intensity, thus stabilizing the surface potential change and resulting in single-point stabilization. In contrast, when the low light intensity in region (a) is selected as the image exposure, as... Figure 3A As shown, the absolute value of the slope of the EV curve is large relative to the change in light intensity, thus destabilizing the surface potential and resulting in destabilizing a single point.

[0042] Simultaneously, to improve the simulated grayscale, it is required that the change in surface potential under varying light intensity be nearly linear. For this purpose, it is appropriate to... Figure 3B In the EV curve, low light intensity is selected as the image exposure. In this case, such as... Figure 3B As shown, when the image exposure is divided equally, the surface potential also becomes relatively close to equal division, thus improving the simulated grayscale. In contrast, when highlight amount is selected as the image exposure, as... Figure 3C As shown, when the image exposure is divided equally, the surface potential moves away from the division, thus degrading the simulated grayscale.

[0043] As mentioned above, analog grayscale and digital grayscale are generally in a barter relationship regarding the selection of which amount of light on the EV curve to use as image exposure.

[0044] As mentioned above, when AR ≤ 0.10 is not satisfied, the shape of the EV curve of the photosensitive element is not optimal. Therefore, as Figure 3A As shown, the regions where digital grayscale is satisfactory and the regions where analog grayscale is satisfactory are far apart. Therefore, when digital grayscale is satisfactory, analog grayscale cannot be fully utilized.

[0045] Next, in Figure 4 The diagram shows the relationship between analog and digital grayscale in the EV curve of a photosensitive element that satisfies AR ≤ 0.10. (Example:) Figure 4 As shown, the light intensity areas that can fully utilize digital grayscale and analog grayscale are close to each other, thus improving the analog grayscale characteristics under high line count halftone while maintaining high-quality digital grayscale.

[0046] [Methods for evaluating the EV curve of electrophotographic photosensitive components]

[0047] The following describes the method for measuring the EV curve in this invention.

[0048] In the measurement of EV curves, a conceptual diagram defining the method for determining EV curves is presented. Figure 5 As shown in the image.

[0049] First, prepare a quartz glass (hereinafter referred to as "NESA glass") as follows: deposit an ITO film 504, which will serve as a transparent ITO electrode, onto the quartz glass so that the surface resistivity of the glass is below 1,000 [Ω / sq]; and optically polish the entire surface of the resulting material to make it transparent. Figure 5 As shown, the surface of the photosensitive element 501 is brought into close contact with the NESA glass 502. At this time, when the photosensitive element 501 has a flat plate shape, smooth NESA glass is used, and when the photosensitive element has a cylindrical shape, a smooth NESA glass is used. Figure 5 The curved NESA glass shown is used. The surface of the photosensitive element can be charged by applying a voltage from a high-voltage power supply 505 to the NESA glass 502 in this state. Furthermore, when a voltage of 805 nm and an intensity of 25 mW / cm² is applied from the lower surface of the NESA glass... 2 When the plane light is exposed to the surface of the photosensitive component for 503, the surface potential light can be attenuated.

[0050] When using the above measurement system, the intensity of the exposure light, stronger than that expected to be applied to the photosensitive components of electrophotographic devices in recent years or the future, can be set to 25 [mW / cm²]. 2 The light is applied to the photosensitive element only once for a short period of time, and the charging and exposure of the photosensitive element can be repeated at a rate faster than the processing speed of electrophotographic devices expected in recent years or in the future. Therefore, it is possible to stably and easily obtain increments of 0.001 μJ / cm². 2 A large amount of data is used to provide the EV curve of the photosensitive component of the present invention. Furthermore, the characteristics of the photosensitive component, which can correspond to the reduction in exposure time due to the increase in processing speed in recent years or in the future, and the reduction in the number of exposures when the exposure method is changed from the currently mainstream laser scanning optical system to an LED array, can be evaluated by the above-described measurement method implemented using this measurement system. In particular, considering the reciprocity failure characteristic of the photosensitive component, the photosensitive component is exposed for a short time to an intensity of 25 [mW / cm²]. 2 The light irradiation conditions of a single exposure are designed to provide a sufficiently rigorous method for measuring EV curves in the future.

[0051] In use Figure 5 The measuring equipment was used according to the following <Method for Measuring EV Curves> at a temperature of 23.5 [°C] and a relative humidity of 50 [%RH] and has an indicator for I. exp The horizontal axis and represent V exp In the graph of the vertical axis, when I in the graphexp =0.500 [μJ / cm 2 V at that time exp By V r [V] represents I in the diagram. exp =0.000~0.030 [μJ / cm] 2 Within the range of S=I exp ·(V exp -V r S[V·μJ / cm] represents 2 The maximum value of ] is determined by S max [V·μJ / cm 2 ] indicates, and in the figure I exp =0.000~0.010 [μJ / cm] 2 Approximate straight line within the range of I exp =0.490~0.500 [μJ / cm 2 The amount of light I on the horizontal axis at the intersection of approximately straight lines within the range of ] i [μJ / cm 2 [and the potential V on the vertical axis] i The product of [V] is given by S i =I i ·(V i -V r )[V·μJ / cm 2 When represented by ], calculate the representation S. i With S max The value of the ratio S i / S max AR.

[0052] <Methods for Measuring EV Curves>

[0053] (1): Set the surface potential of the electrophotographic photosensitive element to 0 [V].

[0054] (2): The electrophotographic photosensitive element is charged for 0.005 seconds so that the absolute value of the initial surface potential of the electrophotographic photosensitive element becomes V0[V].

[0055] (3): 0.02 seconds after the start of charging, the charged electrophotographic photosensitive component is continuously exposed to an atmosphere with a wavelength of 805 nm and an intensity of 25 mW / cm². 2 The light is emitted in seconds, thus achieving an exposure of I. exp [μJ / cm 2 ].

[0056] (4): 0.06 seconds after the start of charging, the absolute value of the surface potential of the electrophotographic photosensitive element after exposure is measured and determined by V. exp [V] indicates.

[0057] (5): At 0.001 [μJ / cm 2 The interval of I will exp From 0.000 [μJ / cm 2 [Changed to 1.000 [μJ / cm]] 2 Simultaneously repeat operations (1) to (4) to obtain the corresponding I. exp V exp .

[0058] (6): In operations (1) to (5), in operation (3) t=0 and I exp =0.000[μJ / cm 2 V at that time exp [V] is specifically referred to as the electric potential V. d [V], and set V0[V] in operation (2) so that V d [V] takes the value of 300V.

[0059] exist Figure 6 The diagram illustrates the calculation of S in this invention. i / S max Concept diagram.

[0060] In having such Figure 4 In the case of the ideal EV curve shown in the present invention, I exp =0.490~0.500 [μJ / cm 2 The slope of the approximate straight line within the range of ] becomes 0, therefore S i =0. However, usually, such as Figure 3C As shown, the photosensitive element cannot fully maintain I exp The slope when S = 0, and the slope gradually approaches 0. Therefore, S i >0, and AR gradually increases. AR is preferably AR≤0.1, more preferably AR≤0.09. Furthermore, when S becomes S max V at time exp and I exp V max and I max Indicates and (V) max -V r ) / I max By LR max When representing, LR max Preferred to satisfy LR max ≥2,000, more preferably LR max ≥3,000. Furthermore, V r [V] Preferably satisfies V r ≤30.

[0061] [Electronic photographic sensor]

[0062] The electrophotographic photosensitive component of the present invention is an organic photosensitive component comprising a support and layers formed on the support, wherein each layer contains a resin as a main component. Figure 1 This diagram illustrates an example of the layered structure of an electrophotographic photosensitive component. Figure 1 In the figure, the support is indicated by reference numeral 101, the base layer is indicated by reference numeral 102, the charge generating layer is indicated by reference numeral 103, the charge transport layer is indicated by reference numeral 104, and the organic photosensitive layer (layered photosensitive layer) is indicated by reference numeral 105.

[0063] As a method for producing the electrophotographic photosensitive component of the present invention, a method is provided that includes preparing a coating liquid for each layer described later, applying the coating liquid in a desired layer sequence, and drying the coating liquid. In this case, as coating methods for the coating liquid, examples include dip coating, spray coating, inkjet coating, roller coating, die coating, blade coating, curtain coating, wire rod coating, and ring coating. Among these, dip coating is preferred from the viewpoint of efficiency and productivity.

[0064] The following describes each layer.

[0065] <Support Body>

[0066] In this invention, the support body is preferably a conductive support body with conductivity. Examples of the shape of the support body include cylindrical, strip, and sheet shapes. Among them, a cylindrical support body is preferred. Examples of conductive support bodies are those in which a thin film of a metal such as aluminum, chromium, silver, or gold, a thin film of a conductive material such as indium oxide, tin oxide, or zinc oxide, or a thin film of conductive ink in which silver nanowires are added are formed on a support body made of a metal or alloy such as aluminum, iron, nickel, copper, or gold, or an insulating support body such as polyester resin, polycarbonate resin, polyimide resin, or glass.

[0067] The surface of the support can be subjected to electrochemical treatments such as anodizing, wet honing, sandblasting, or cutting to improve its electrical properties and suppress interference fringes.

[0068] <Conductive Layer>

[0069] In this invention, a conductive layer can be provided on the support. Providing a conductive layer can cover the unevenness and defects of the support and prevent interference fringes. The average thickness of the conductive layer is preferably 5 μm or more and 40 μm or less, more preferably 10 μm or more and 30 μm or less.

[0070] The conductive layer preferably comprises conductive particles and a binder resin. Examples of conductive particles include carbon black, metal particles, and metal oxide particles. 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. Metal oxides are preferred as conductive particles, and particularly, titanium oxide, tin oxide, and zinc oxide are more preferred.

[0071] When metal oxides are used as conductive particles, the surface of the metal oxide can be treated with a silane coupling agent, or the metal oxide can be doped with elements such as phosphorus or aluminum, or their oxides. Examples of elements and their oxides used for doping include phosphorus, aluminum, niobium, and tantalum.

[0072] Furthermore, each conductive particle can be a stack having a core particle and a coating layer covering the particle. Examples of core particles include titanium oxide, barium sulfate, and zinc oxide. Examples of coating layers include metal oxides such as tin oxide and titanium oxide.

[0073] 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.

[0074] 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. Furthermore, the conductive layer may further comprise a masking agent such as silicone oil, resin particles, or titanium dioxide.

[0075] The average thickness of the conductive layer is preferably 1 μm or more and 50 μm or less, particularly preferably 3 μm or more and 40 μm or less. The conductive layer can be formed by preparing a coating liquid containing the above-described materials and solvents, forming a coating film thereon, and drying the coating film. Examples of solvents to be 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. Dispersion methods for dispersing conductive particles in the coating liquid for the conductive layer include, for example, methods using a paint mixer, a sand mill, a ball mill, or a high-speed liquid impact disperser.

[0076] <Undercoat>

[0077] In this invention, a base coating layer can be provided on the support or conductive layer, and a configuration including a base coating layer formed between the support and the charge-generating layer is preferred. Providing a base coating layer improves interlayer adhesion and can impart charge injection prevention functionality.

[0078] 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.

[0079] Examples of resins include polyester resins, polycarbonate resins, polyvinyl alcohol acetal resins, acrylic resins, epoxy resins, melamine resins, polyurethane resins, phenolic resins, polyvinylphenolic 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.

[0080] 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.

[0081] Furthermore, to improve electrical properties, the base coating may further comprise electron transport materials, metal oxides, metals, or conductive polymers, and may undergo surface treatment as needed. Electron transport materials or metal oxides are preferred.

[0082] Examples of electron transport materials include quinone compounds, imide compounds, benzimidazole compounds, cyclopentadiene 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 monomers having polymerizable functional groups to form a cured film as the undercoating layer.

[0083] 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. Among these, titanium oxide is preferred.

[0084] The case where the base coating according to the invention comprises polyamide resin and surface-treated titanium dioxide particles is preferred.

[0085] From the viewpoint of suppressing charge accumulation, the crystal structure of each titanium oxide particle is preferably rutile or anatase, and more preferably rutile with weak photocatalytic activity. When the crystal structure is rutile, the rutile content of the particles is preferably 90% or more. The shape of each titanium oxide particle is preferably spherical, and from the viewpoint of suppressing charge accumulation and uniform dispersion, its average primary particle size "b" [μm] is preferably 0.006 or more and 0.180 or less, more preferably 0.015 or more and 0.085 or less. It is preferable to surface treat the titanium oxide particles with a compound represented by the following formula (1).

[0086]

[0087] In equation (1), R 1 Indicates methyl, ethyl, acetyl, or 2-methoxyethyl, R 2 Representing a hydrogen atom or a methyl group, m+n=3, where "m" represents an integer greater than or equal to 0, and "n" represents an integer greater than or equal to 1, provided that when "n" represents 3, R 2 It does not exist.

[0088] Specifically, the titanium dioxide particles are preferably surface-treated with at least one compound selected from vinyltrimethoxysilane, vinyltriethoxysilane, and vinylmethyldimethoxysilane.

[0089] In the base coating, the volume ratio of titanium oxide particles to polyamide resin (volume of titanium oxide particles relative to volume of polyamide resin) "a" is preferably 0.2 or more and 1.0 or less. When "a" is less than 0.2, the effect of suppressing charge accumulation as described in this invention cannot be sufficiently obtained, and when "a" is greater than 1.0, the effect of suppressing peeling of the photosensitive layer as described in this invention cannot be sufficiently obtained. A more preferred range for "a" is 0.3 or more and less than 0.8.

[0090] In particular, when the average primary particle size of titanium oxide particles is represented by "b", within the preferred range of "a" and "b", when a / b satisfies the following expression (A), two effects can be achieved simultaneously at a high level: suppressing the peeling of the photosensitive layer and suppressing the accumulation of charge remaining in the base layer.

[0091] Expression (A): 14.0 ≤ a / b ≤ 19.1

[0092] In addition, the base coat may contain additives.

[0093] 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.

[0094] The base coat can be formed by preparing a coating liquid containing the above-mentioned materials and solvents, forming the coating film thereon, and drying and / or curing the coating film. Examples of solvents to be used in the coating liquid include alcohol solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

[0095] <Photosensitive layer>

[0096] The photosensitive layer of an electrophotographic photosensitive component is preferably an organic photosensitive layer. The photosensitive layer includes a charge generation layer and a charge transport layer.

[0097] (1-1) Charge generation layer

[0098] The charge-generating layer preferably comprises a charge-generating substance and a binder resin.

[0099] According to a preferred embodiment of the present invention, a charge-generating layer is disposed directly above the base layer. The charge-generating layer of the present invention is obtained by dispersing a charge-generating substance and a binder resin as needed in a solvent to prepare a coating liquid for the charge-generating layer; forming a coating film of the coating liquid for the charge-generating layer; and drying the coating film.

[0100] The average thickness of the charge generation layer is preferably 0.10 μm or more and 1.00 μm or less, more preferably 0.15 μm or more and 0.40 μm or less, and particularly preferably 0.20 μm or more and 0.30 μm or less.

[0101] The coating solution for the charge-generating layer can be prepared by adding only the charge-generating substance to a solvent and dispersing the mixture; then, adding a binder resin to it. Alternatively, the coating solution can be prepared by adding the charge-generating substance and the binder resin together to a solvent and dispersing the mixture.

[0102] For dispersion, media dispersers such as sand mills or ball mills, or dispersers such as liquid impact dispersers or ultrasonic dispersers can be used.

[0103] Examples of adhesive resins for use in charge-generating layers include resins (insulating resins), such as polyvinyl butyral resin, polyvinyl acetal resin, polyarylate resin, polycarbonate resin, polyester resin, polyvinyl acetate resin, polysulfone resin, polystyrene resin, phenoxy resin, acrylic resin, phenoxy resin, polyacrylamide resin, polyvinylpyridine resin, polyurethane resin, agarose resin, cellulose resin, casein resin, polyvinyl alcohol resin, polyvinylpyrrolidone resin, vinylidene chloride resin, acrylonitrile copolymer, and polyvinyl benzaldehyde resin. Additionally, organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinyl anthracene, and polyvinyl pyrene can also be used. Furthermore, adhesive resins can be used alone or in mixtures or copolymers thereof.

[0104] Examples of solvents that can be used in coating solutions for the charge-generating layer include toluene, xylene, tetrahydronaphthalene, chlorobenzene, dichloromethane, chloroform, trichloroethylene, tetrachloroethylene, carbon tetrachloride, methyl acetate, ethyl acetate, propyl acetate, methyl formate, ethyl formate, acetone, methyl ethyl ketone, cyclohexanone, diethyl ether, dipropyl ether, propylene glycol monomethyl ether, dioxane, methyl acetal, tetrahydrofuran, water, methanol, ethanol, n-propanol, isopropanol, butanol, methyl cellosolve, methoxypropanol, dimethylformamide, dimethylacetamide, and dimethyl sulfoxide. Furthermore, solvents can be used alone or in mixtures thereof.

[0105] Examples of charge-generating materials for use in charge-generating layers include azo pigments, perylene pigments, polycyclic quinone pigments, indigo pigments, and phthalocyanine pigments. Phthalocyanine pigments are preferred, with titanium dioxide phthalocyanine pigments and hydroxy gallium phthalocyanine pigments being more preferred. These pigments may each have axial ligands or substituents.

[0106] Furthermore, the hydroxygallium phthalocyanine pigment preferably comprises grains exhibiting peaks at Bragg angles 2θ of 7.4°±0.3° and 28.2°±0.3° in X-ray diffraction spectra using CuKα rays. Additionally, the pigment preferably has peaks in the grain size distribution measured using small-angle X-ray scattering in the range of 20 nm to 50 nm, and the half-width of the peaks is preferably less than 50 nm.

[0107] Furthermore, hydroxygallium phthalocyanine pigments more preferably include grains each containing an amide compound represented by formula (A1). Examples of amide compounds represented by formula (A1) include N-methylformamide, N-propylformamide, and N-vinylformamide. Among them, N-methylformamide is preferred.

[0108]

[0109] In equation (A1), R 1 It indicates methyl, propyl, or vinyl.

[0110] Furthermore, the content of the amide compound represented by formula (A1) to be included in the grain is preferably 0.1% by mass or more and 3.0% by mass or less relative to the content of the grain, more preferably 0.1% by mass or more and 1.4% by mass or less. When the content of the amide compound is 0.1% by mass or more and 3.0% by mass or less, the size of the grain can be uniformly adjusted to a suitable size.

[0111] Phthalocyanine pigments containing amide compounds represented by formula (A1) within their individual grains are obtained by a process of crystallization of phthalocyanine pigments obtained by acid dissolution and amide compounds represented by formula (A1) through wet milling.

[0112] When a dispersant is used in the grinding process, the amount of dispersant is preferably 10 to 50 times the mass of the phthalocyanine pigment. Examples of solvents to be used include: amide solvents, such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylformamide, compounds represented by formula (A1), N-methylacetamide, and N-methylpropionamide; halogen solvents, such as chloroform; ether solvents, such as tetrahydrofuran; and sulfoxide solvents, such as dimethyl sulfoxide. N-methylformamide is preferred. When N-methylformamide is used, the half-width at half-maximum (WHM) of the peaks in the grain size distribution can be made sharper. Furthermore, the amount of solvent used is preferably 5 to 30 times the mass of the phthalocyanine pigment.

[0113] Whether hydroxy gallium phthalocyanine pigments contain amide compounds represented by formula (A1) within their individual grains can be determined by analyzing the obtained hydroxy gallium phthalocyanine pigments. 1 The content of the amide compound represented by formula (A1) in the grains was determined by H-NMR measurements. 1 The determination is made through data analysis of H-NMR measurements. For example, the resulting hydroxygallium phthalocyanine pigment is subjected to grinding treatment or a post-grinding washing process using a solvent capable of dissolving amide compounds represented by formula (A1). 1 H-NMR measurement. When an amide compound represented by formula (A1) is detected, it can be determined that the crystal contains an amide compound represented by formula (A1).

[0114] The electrophotographic photosensitive component of the present invention includes phthalocyanine pigment powder X-ray diffraction measurement and 1 H-NMR measurements were performed under the following conditions.

[0115] (Powder X-ray diffraction measurement)

[0116] Measuring apparatus used: RINT-TTR II X-ray diffractometer, manufactured by Rigaku Corporation; X-ray tube: Cu

[0117] X-ray wavelength: Kα1

[0118] Tube voltage: 50KV

[0119] Tube current: 300mA

[0120] Scanning method: 2θ scan

[0121] Scanning speed: 4.0° / min

[0122] Sampling interval: 0.02°

[0123] Initial angle 2θ: 5.0°

[0124] Termination angle 2θ: 35.0°

[0125] Angle measuring instrument: Rotor horizontal angle measuring instrument (TTR-2)

[0126] Attachment: Capillary Rotating Sample Stage

[0127] Filter: Not used

[0128] Detector: Blink Counter

[0129] Incident monochromator: using

[0130] Slit: Variable slit (parallel beam method)

[0131] Counter monochromator: Not used

[0132] Diverging slit: Open

[0133] Longitudinal diverging slit: 10.00mm

[0134] Scattering slit: Open

[0135] Receiving slit: Open

[0136] ( 1 H-NMR measurement)

[0137] Measuring instrument used: AVANCE III 500, manufactured by Bruker Corporation.

[0138] Solvent: Deuterated sulfuric acid (D2SO4)

[0139] Number of scans: 2,000

[0140] (1-2) Charge transport layer

[0141] The charge transport layer preferably comprises a charge transport material and a resin.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] The ratio (mass ratio) of charge transport material to resin is preferably 4:10 to 20:10, more preferably 5:10 to 12:10.

[0146] In addition, the charge transport layer may contain additives such as antioxidants, UV absorbers, plasticizers, leveling agents, smoothing agents, or abrasion 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.

[0147] The average thickness of the charge transport layer is preferably 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.

[0148] 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 to be 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.

[0149] <Protective Layer>

[0150] In this invention, a protective layer can be formed on the photosensitive layer. Forming a protective layer improves durability.

[0151] The protective layer preferably comprises conductive particles and / or charge-transporting substances, as well as resin.

[0152] Examples of conductive particles include particles of metal oxides such as titanium oxide, zinc oxide, tin oxide, and indium oxide.

[0153] 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.

[0154] 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.

[0155] Furthermore, the protective layer can be formed into a cured film by polymerizing a composition containing monomers having polymerizable functional groups. Examples of reactions in this case include thermal polymerization, photopolymerization, and radiation polymerization. Examples of polymerizable functional groups in monomers include acryloyl and methacryloyl groups. Materials with charge-transporting capabilities can be used as monomers with polymerizable functional groups.

[0156] The protective layer may contain additives such as antioxidants, UV absorbers, plasticizers, leveling agents, smoothing agents, or abrasion 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.

[0157] 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.

[0158] The protective layer can be formed by preparing a coating liquid containing the above-mentioned materials and solvents, forming the coating film thereon, and drying and / or curing the coating film. Examples of solvents to be used in the coating liquid include alcohol solvents, ketone solvents, ether solvents, sulfoxide solvents, ester solvents, and aromatic hydrocarbon solvents.

[0159] [Processing box and electrophotographic equipment]

[0160] An example of the schematic configuration of an electrophotographic device having a processing box including an electrophotographic photosensitive element is shown in Figure 2 As shown in [the image]. Figure 2 In the middle, the cylindrical (drum-shaped) electrophotographic photosensitive component 1 is driven to rotate around the axis 2 in the direction indicated by the arrow at a predetermined circumferential speed (processing speed).

[0161] The surface of the electrophotographic photosensitive member 1 is charged to a predetermined positive or negative potential during its rotation using the charging unit 3. Next, exposure light 4 is applied from an image exposure unit (not shown) to the charged surface of the electrophotographic photosensitive member 1 to form an electrostatic latent image corresponding to the target image information. The exposure light 4 is light emitted from an image exposure unit such as slit exposure or laser beam scanning exposure, and its intensity is modulated according to a time-series electro-digital image signal corresponding to the target image information.

[0162] The toner stored in the developing unit 5 is used to develop the electrostatic latent image formed on the surface of the electrophotographic photosensitive member 1 (normal development or reverse development) to form a toner image on the surface of the electrophotographic photosensitive member 1. The toner image formed on the surface of the electrophotographic photosensitive member 1 is transferred to the transfer material 7 by the transfer unit 6. At this time, a bias voltage with a polarity opposite to the charge held by the toner is applied to the transfer unit 6 from a bias power supply (not shown). Furthermore, when the transfer material 7 is paper, the transfer material 7 is taken out from the paper feed section (not shown) and fed synchronously with the rotation of the electrophotographic photosensitive member 1 into the gap between the electrophotographic photosensitive member 1 and the transfer unit 6.

[0163] The transfer material 7, on which the toner image from the electrophotographic photosensitive component 1 is transferred, is separated from the surface of the electrophotographic photosensitive component 1 and then conveyed to the fixing unit 8, which performs toner image fixing processing on the transfer material. Thus, the transfer material is printed as an image (print or copy) onto the exterior of the electrophotographic device. The surface of the electrophotographic photosensitive component 1 after the toner image is transferred onto the transfer material 7 is cleaned by the cleaning unit 9 as follows: adhering substances such as toner (transfer residual toner) are removed from the surface. With the help of a cleaner-free system developed in recent years, the transfer residual toner can be directly removed using a developing device or the like. Furthermore, the surface of the electrophotographic photosensitive component 1 is subjected to a pre-exposure light 10 from the pre-exposure unit (not shown) for de-energization treatment, and then repeatedly used for image formation. When the charging unit 3 is a contact charging unit using a charging roller or the like, the pre-exposure unit is not necessarily required. In this invention, multiple components, such as the aforementioned electrophotographic photosensitive element 1, charging unit 3, developing unit 5, and cleaning unit 9, are housed in a container and integrally supported to form a processing box. The processing box can be detachably mounted to the body of the electrophotographic device. For example, at least one of the charging unit 3, developing unit 5, and cleaning unit 9 is integrally supported with the electrophotographic photosensitive element 1 to form a box. This box can be a processing box 11 detachably mounted to the body of the electrophotographic device using a guide unit 12, such as a guide rail. When the electrophotographic device is a copier or printer, the exposure light 4 can be reflected or transmitted light from the original document. Optionally, the exposure light can be light emitted by, for example, scanning using a laser beam, driving an LED array, or driving a liquid crystal shutter array according to a signal obtained by reading the original document with a sensor and converting it into a signal.

[0164] The electrophotographic photosensitive component of the present invention can be widely used in fields such as laser beam printers, CRT printers, LED printers, fax machines, LCD printers, and laser plate making, which utilize electrophotography.

[0165] [Example]

[0166] The invention is described in more detail below with reference to embodiments and comparative examples. The invention is not limited to the following embodiments without departing from its spirit. In the description of the following embodiments, unless otherwise stated, "parts" are based on mass.

[0167] Apart from the charge-generating layer, the thickness of each layer of the electrophotographic photosensitive component in the embodiments and comparative examples was determined by either a method including the use of an eddy current thickness gauge (Fischerscope, manufactured by Fischer Instruments KK) or a method including converting the mass per unit area of ​​the layer into its thickness by using the specific gravity of the layer. The thickness of the charge-generating layer was measured by converting the Macbeth concentration value of the photosensitive component, measured by pressing a spectrophotometer (product name: X-Rite 504 / 508, manufactured by X-Rite Inc.) against the surface of the photosensitive component, using a calibration curve obtained in advance from Macbeth concentration values ​​and thickness values ​​measured by observing cross-sectional SEM images of the layer.

[0168] <Preparation of Coating Solution 1 for Conductive Layer>

[0169] Using anatase titanium dioxide with an average primary particle size of 200 nm as the matrix, a titanium-niobium sulfuric acid solution containing 33.7 parts of titanium (based on TiO2) and 2.9 parts of niobium (based on Nb2O5) was prepared. 100 parts of the matrix were dispersed in pure water to provide a suspension of 1,000 parts, and the suspension was heated to 60 °C. The titanium-niobium sulfuric acid solution and 10 mol / L sodium hydroxide were added dropwise to the suspension over 3 hours to adjust the pH to 2-3. After the total volume of the solution was added, the pH was adjusted to near the neutral zone, and a polyacrylamide-based flocculant was added to the mixture to allow the solids to settle. The supernatant was removed, and the residue was filtered, washed, and then dried at 110 °C. This yielded an intermediate containing 0.1 wt% organic matter derived from the flocculant (based on C). The intermediate was calcined in nitrogen at 750 °C for 1 hour, and then calcined in air at 450 °C to produce titanium dioxide particles.

[0170] Subsequently, 50 parts of phenolic resin (monomers / oligomers of phenolic resin) (product name: PLYOPHEN J-325, manufactured by DIC Corporation, resin solids content: 60%, density after curing: 1.3 g / cm³) were used as the adhesive material. 3 Dissolved in 35 parts of 1-methoxy-2-propanol as a solvent to provide a solution.

[0171] 60 parts of titanium dioxide particles were added to the solution. The mixture was fed into a vertical sand mill using 120 parts of glass beads with an average particle size of 1.0 mm as the dispersion medium, and dispersed for 4 hours at a dispersion temperature of 23℃±3℃ and a speed of 1,500 rpm (circumferential speed: 5.5 m / s) to provide a dispersion. The glass beads were removed from the dispersion using a sieve. 0.01 parts of silicone oil (product name: SH28 PAINTADDITIVE, manufactured by Dow Corning Toray Co., Ltd.) as a leveling agent and 8 parts of silicone resin particles (product name: KMP-590, manufactured by Shin-Etsu Chemical Co., Ltd., average particle size: 2 μm, density: 1.3 g / cm³) as a surface roughening material were added. 3 Add the mixture to the dispersion after removing the glass beads and stir the mixture. Filter the mixture under pressure using PTFE filter paper (product name: PF060, manufactured by Advantec Toyo Kaisha, Ltd.) to prepare coating solution 1 for the conductive layer.

[0172] <Preparation of Coating Solution 2 for Conductive Layer>

[0173] 214 parts of titanium dioxide (TiO2) particles coated with oxygen-deficient tin oxide (SnO2) as metal oxide particles, 132 parts of phenolic resin (monomer / oligomer of phenolic resin) (product name: PLYOPHEN J-325, manufactured by Dainippon Ink and Chemicals, Incorporated, resin solids content: 60% by mass) as a binder, and 98 parts of 1-methoxy-2-propanol as a solvent were added to a sand mill with 450 parts of glass beads, each with a diameter of 0.8 mm, and dispersed at 2,000 rpm for 4.5 hours and with a preset cooling water temperature of 18°C ​​to provide a dispersion. The glass beads were removed from the dispersion using a sieve (aperture: 150 μm). Silicone resin particles (product name: TOSPEARL 120, manufactured by Momentive Performance Materials, average particle size: 2 μm), used as a surface roughening material, were added to the dispersion at a rate of 10% by mass relative to the total mass of metal oxide particles and binder material in the dispersion after removing glass beads. Furthermore, silicone oil (product name: SH28PA, manufactured by DowCorning Toray Co., Ltd.), used as a leveling agent, was added to the dispersion at a rate of 0.01% by mass relative to the total mass of metal oxide particles and binder material in the dispersion, and the mixture was stirred. Thus, coating liquid 2 for preparing the conductive layer was obtained.

[0174] <Preparation of Coating Solution 1 for the Primer Coating>

[0175] 100 parts of rutile titanium dioxide particles (average primary particle size: 50 nm, manufactured by Tayca Corporation) were mixed with 500 parts of toluene, and 3.5 parts of vinyltrimethoxysilane (product name: KBM-1003, manufactured by Shin-Etsu Chemical Co., Ltd.) were added. The mixture was then dispersed in a vertical sand mill using glass beads with a diameter of 1.0 mm for 8 hours. After removing the glass beads, toluene was removed by vacuum distillation, and the residue was dried at 120°C for 3 hours. This yielded rutile titanium dioxide particles surface-treated with an organosilicon compound.

[0176] A dispersion was prepared by adding 18.0 parts of rutile titanium dioxide particles surface-treated with organosilicon compounds, 4.5 parts of N-methoxymethylated nylon (product name: TORESIN EF-30T, manufactured by Nagase ChemteX Corporation) and 1.5 parts of copolymerized nylon resin (product name: AMILAN CM8000, manufactured by Toray Industries, Inc.) to a mixed solvent of 90 parts methanol and 60 parts 1-butanol.

[0177] The dispersion was dispersed in a vertical sand mill using glass beads of 1.0 mm diameter for 5 hours, and the glass beads were then removed. This prepared the base coat coating liquid 1. When the ratio of the volume of titanium dioxide particles to the volume of the resulting polyamide resin was denoted by "a" and the average primary particle size of the titanium dioxide particles was denoted by "b" [μm], a / b = 15.6 was found. After the production of the electrophotographic photosensitive component, the value of "a" was calculated from the area ratio in a cross-sectional photomicrograph of the electrophotographic photosensitive component taken using a field emission scanning electron microscope (FE-SEM, product name: S-4800, manufactured by Hitachi High-Technologies Corporation).

[0178] <Preparation of Coating Liquid 2 for the Primer>

[0179] 4.5 parts of N-methoxymethylated nylon (product name: TORESIN EF-30T, manufactured by Nagase ChemteX Corporation) and 1.5 parts of copolynylon resin (product name: AMILAN CM8000, manufactured by Toray Industries, Inc.) were added to a mixed solvent of 90 parts methanol and 45 parts 1-butanol, and the mixture was stirred at 40°C for 2 hours to prepare coating liquid 2 for the primer layer.

[0180] <Preparation of Coating Liquid 3 for the Primer Coating>

[0181] Except for changing the amount of surface-treated rutile titanium dioxide particles used in the preparation of the primer coating liquid 1 from 18.0 parts to 22.0 parts, the primer coating liquid 3 was prepared in the same manner. When the ratio of the volume of titanium dioxide particles to the volume of the resulting polyamide resin is represented by "a" and the average primary particle size of the titanium dioxide particles is represented by "b" [μm], it was found that a / b = 19.1.

[0182] <Preparation of Coating Liquid 4 for the Primer Coating>

[0183] Except for changing the amount of surface-treated rutile titanium dioxide particles used in the preparation of the primer coating liquid 1 from 18.0 parts to 20.8 parts, the amount of N-methoxymethylated nylon (product name: TORESIN EF-30T, manufactured by NagaseChemteX Corporation) used from 4.5 parts to 3.9 parts, and the amount of copolymer nylon resin (product name: AMILAN CM8000, manufactured by Toray Industries, Inc.) used from 1.5 parts to 1.3 parts, the primer coating liquid 4 is prepared in the same manner.

[0184] When the ratio of the volume of titanium oxide particles to the volume of the resulting polyamide resin is represented by "a" and the average primary particle size of the titanium oxide particles is represented by "b" [μm], it is found that a / b = 20.8.

[0185] <Preparation of coating liquid 5 for the base coating>

[0186] Except for changing the amount of surface-treated rutile titanium dioxide particles used in the preparation of the primer coating liquid 1 from 18.0 parts to 15.0 parts, the primer coating liquid 5 was prepared in the same manner. When the ratio of the volume of titanium dioxide particles to the volume of the resulting polyamide resin is represented by "a" and the average primary particle size of the titanium dioxide particles is represented by "b" [μm], it was found that a / b = 13.0.

[0187] <Preparation of Coating Liquid 6 for the Primer Coating>

[0188] 4.6 parts of the compound represented by formula (7), used as an electron transport material, and 8.6 parts of a capped isocyanate compound (product name: SBN-70D, manufactured by Asahi Kasei Corporation) were dissolved in a mixed solvent of 48 parts 1-methoxy-2-propanol and 48 parts tetrahydrofuran. Additionally, 0.3 parts of silica particles (product name: RX200, manufactured by Nippon Aerosil Co., Ltd.) were added, and the mixture was stirred. Thus, a coating liquid 6 for the primer layer was prepared.

[0189]

[0190] Synthesis of Phthalocyanine Pigments

[0191] <Synthesis example 1>

[0192] Under a nitrogen atmosphere, 5.46 parts of phthalonitrile and 45 parts of α-chloronaphthalene were added to a reaction vessel. The mixture was then heated to 30°C and maintained at this temperature. Next, 3.75 parts of gallium trichloride were added to the vessel at this temperature (30°C). The water concentration of the mixture at the time of addition was 150 ppm. The temperature was then raised to 200°C. The product was then reacted at 200°C for 4.5 hours under a nitrogen atmosphere, followed by cooling. When the temperature reached 150°C, the product was filtered. The resulting filter residue was dispersed with N,N-dimethylformamide at 140°C and washed for 2 hours, followed by filtration. The resulting filter residue was washed with methanol and then dried to provide gallium chlorophthalocyanine pigment in 71% yield.

[0193] <Synthesis example 2>

[0194] More than 4.65 parts of the gallium chlorophthalocyanine pigment obtained in Synthesis Example 1 were dissolved in 139.5 parts of concentrated sulfuric acid at 10°C. The solution was added dropwise to 620 parts of ice water with stirring to precipitate again. The precipitate was filtered under reduced pressure using a filter press. A No. 5C filter (manufactured by Advantec) was used as the filter. The resulting wet filter cake (filtration residue) was dispersed in 2% ammonia water and washed for 30 minutes, then filtered using a filter press. Next, the resulting wet filter cake (filtration residue) was dispersed in deionized water and washed, then filtered three times repeatedly using a filter press. Finally, the result was freeze-dried to provide a hydroxy gallium phthalocyanine pigment (aqueous hydroxy gallium phthalocyanine pigment) with a solids content of 23%, in a yield of 97%.

[0195] <Synthesis example 3>

[0196] As described below, 6.6 kg of the hydroxygallium phthalocyanine pigment obtained in Synthesis Example 2 was dried using a hyper-dry dryer (product name: HD-06R, frequency (oscillation frequency):

[0197] 2,455MHz±15MHz (manufactured by Biocon (Japan) Ltd.) for drying.

[0198] Immediately after being removed from the filter press, the hydroxygallium phthalocyanine pigment was placed in clumps (water-containing filter cake thickness: less than 4 cm) on a dedicated circular plastic tray, and a dryer was set up to turn off far-infrared radiation and raise the temperature of the dryer's inner wall to 50°C. Then, while irradiating the pigment with microwaves, the vacuum pump and vent valve of the dryer were adjusted to regulate its vacuum level to 4.0 kPa to 10.0 kPa.

[0199] First, as the first step, the hydroxygallium phthalocyanine pigment is irradiated with a microwave with an output of 4.8 kW for 50 minutes. Next, the microwave is temporarily turned off, and the vent valve is temporarily closed to achieve a high vacuum of less than 2 kPa. At this point, the solid content of the hydroxygallium phthalocyanine pigment is 88%. As the second step, the vent valve is adjusted to bring the vacuum level (pressure inside the dryer) within the aforementioned preset value (4.0 kPa to 10.0 kPa). Then, the hydroxygallium phthalocyanine pigment is irradiated with a microwave with an output of 1.2 kW for 5 minutes. Again, the microwave is temporarily turned off, and the vent valve is temporarily closed to achieve a high vacuum of less than 2 kPa. The second step is repeated once more (a total of two times). At this point, the solid content of the hydroxygallium phthalocyanine pigment is 98%. Furthermore, as the third step, microwave irradiation is performed in the same manner as in the second step, except that the microwave output is changed from 1.2 kW to 0.8 kW. The third step is repeated once more (a total of two times). Furthermore, as a fourth step, the vent valve is adjusted to restore the vacuum level (pressure inside the dryer) to the aforementioned preset value (4.0 kPa to 10.0 kPa). Thereafter, the hydroxy gallium phthalocyanine pigment is irradiated with a microwave with an output of 0.4 kW for 3 minutes. Then, the microwave is temporarily turned off, and the vent valve is temporarily closed to achieve a high vacuum of less than 2 kPa. This fourth step is repeated 7 times (a total of 8 times). Thus, 1.52 kg of hydroxy gallium phthalocyanine pigment (crystals) with a water content of less than 1% is obtained within a total of 3 hours.

[0200] <Synthesis example 4>

[0201] In 1,000 g of α-chloronaphthalene, 50 g of phthalonitrile and 20 g of titanium tetrachloride were heated and stirred at 200 °C for 3 hours, then cooled to 50 °C to precipitate crystals. The crystals were separated by filtration to provide a paste of titanium phthalocyanine dichloro. Next, the paste was stirred and washed with 1,000 mL of N,N-dimethylformamide heated to 100 °C, then washed twice repeatedly with 1,000 mL of methanol at 60 °C and separated by filtration. Furthermore, the resulting paste was stirred in 1,000 mL of deionized water at 80 °C for 1 hour and separated by filtration to provide 43 g of blue titanium phthalocyanine pigment.

[0202] Next, the pigment was dissolved in 300 mL of concentrated sulfuric acid. The solution was added dropwise to 3,000 mL of deionized water at 20 °C with stirring to precipitate again. The precipitate was filtered and thoroughly washed with water to provide amorphous titanium dioxide phthalocyanine pigment. 40 g of the amorphous titanium dioxide phthalocyanine pigment was suspended in 1,000 mL of methanol at room temperature (22 °C) and stirred for 8 hours. The resulting product was separated by filtration and dried under reduced pressure to provide titanium dioxide phthalocyanine pigment with low crystallinity.

[0203] <Synthesis example 5>

[0204] Under a nitrogen atmosphere, 100 g of gallium trichloride and 291 g of phthalonitrile were added to 1,000 mL of α-chloronaphthalene, and the mixture was reacted at 200 °C for 24 hours. The product was then filtered. The resulting wet filter cake was heated and stirred in N,N-dimethylformamide at 150 °C for 30 minutes, and then the mixture was filtered. The resulting filtration residue was washed with methanol and then dried to provide gallium chlorophthalocyanine pigment in 83% yield.

[0205] 20 g of the gallium chlorophthalocyanine pigment obtained by the above method was dissolved in 500 mL of concentrated sulfuric acid, and the solution was stirred for 2 hours. Subsequently, the solution was added dropwise to a mixture of 1,700 mL of distilled water and 660 mL of concentrated ammonia, which had been cooled with ice, to precipitate again. The precipitate was thoroughly washed with distilled water and dried to provide the hydroxygallium phthalocyanine pigment.

[0206] <Preparation of Coating Solution 1 for Charge Generation Layer>

[0207] 0.5 parts of the hydroxygallium phthalocyanine pigment obtained in Synthesis Example 3, 9.5 parts of N-methylformamide (product code: F0059, manufactured by Tokyo Chemical Industry Co., Ltd.), and 15 parts of glass beads, each with a diameter of 0.9 mm, were milled at room temperature (23°C) for 100 hours using a sand mill (BSG-20, manufactured by IMEX Co., Ltd.). During this process, the disc was rotated at 1,500 times per minute. The resulting liquid was filtered through a filter (product code: N-NO.125T, pore size: 133 μm, manufactured by NBC Meshtec Inc.) to remove the glass beads. 30 parts of N-methylformamide were added to the resulting liquid, and the mixture was filtered. The filtrate on the filtration device was thoroughly washed with tetrahydrofuran. The washed filtrate was then vacuum dried to provide 0.46 parts of the hydroxygallium phthalocyanine pigment. The resulting pigment contained N-methylformamide.

[0208] The obtained pigment exhibited peaks at Bragg angles of 2θ° of 7.5°±0.2°, 9.9°±0.2°, 16.2°±0.2°, 18.6°±0.2°, 25.2°±0.2°, and 28.3°±0.2° in the X-ray diffraction spectrum using CuKα rays.

[0209] Subsequently, 20 parts of hydroxygallium phthalocyanine pigment obtained during the grinding process, 10 parts of polyvinyl butyral (product name: S-LEC BX-1, manufactured by Sekisui Chemical Co., Ltd.), 190 parts of cyclohexanone, and 482 parts of glass beads, each with a diameter of 0.9 mm, were dispersed in a sand mill (K-800, manufactured by Igarashi Machine Co., Ltd. (now IMEX Co., Ltd.), cyclohexanone, and 5 discs) at a cooling water temperature of 18°C ​​for 4 hours. During this process, the discs were rotated at 1,800 times per minute. The glass beads were removed from the resulting dispersion, and 444 parts of cyclohexanone and 634 parts of ethyl acetate were added. Thus, coating solution 1 for the charge-generating layer was prepared.

[0210] <Preparation of Coating Solution 2 for Charge Generation Layer>

[0211] Except for changing the process of obtaining hydroxy gallium phthalocyanine pigment in the preparation of coating liquid 1 for charge generation layer as described below, coating liquid 2 for charge generation layer is prepared in the same manner as coating liquid 1 for charge generation layer.

[0212] 0.5 parts of the hydroxygallium phthalocyanine pigment obtained in Synthesis Example 5, 7.5 parts of N,N-dimethylformamide (product code: D0722, manufactured by Tokyo Chemical Industry Co., Ltd.), and 29 parts of glass beads with a diameter of 0.9 mm were milled at 25°C for 24 hours using a sand mill (BSG-20, manufactured by IMEX Co., Ltd.). The treatment was carried out at a disk rotation rate of 1,500 times per minute. The treated liquid was then filtered through a filter (product number: N-NO.125T, pore size: 133 μm, manufactured by NBC Meshtec Inc.) to remove the glass beads. 30 parts of N,N-dimethylformamide were added to the resulting liquid, and the mixture was filtered. The filtrate on the filtration device was thoroughly washed with n-butyl acetate. The washed filtrate was then vacuum dried to provide 0.45 parts of the hydroxygallium phthalocyanine pigment. The resulting pigment contains N,N-dimethylformamide.

[0213] <Preparation of Coating Solution 1 for Charge Transport Layer>

[0214] 3.6 parts of a triarylamine compound represented by the following formula (CTM-1) will be used as a charge transport material.

[0215]

[0216] and 5.4 parts of a triarylamine compound represented by the following formula (CTM-2)

[0217]

[0218] 10 parts of polycarbonate resin (product name: Iupilon Z-400, manufactured by Mitsubishi Engineering-Plastics Corporation) were dissolved in a mixed solvent of 25 parts o-xylene, 25 parts methyl benzoate, and 25 parts dimethoxymethane. Thus, coating solution 1 for the charge transport layer was prepared.

[0219] <Preparation of Coating Solution 2 for Charge Transport Layer>

[0220] Nine portions of a triphenylamine compound represented by the following formula (CTM-3) were used as charge transport substances.

[0221]

[0222] Ten parts of a polyarylate resin having structural units represented by formula (3-1) and formula (3-2) in a 5 / 5 ratio and having a weight-average molecular weight of 100,000 are dissolved in a mixed solvent of 30 parts dimethoxymethane and 70 parts chlorobenzene. Thus, coating solution 2 for the charge transport layer is prepared.

[0223]

[0224] <Preparation of Coating Solution 3 for Charge Transport Layer>

[0225] Except that the polycarbonate resin in the preparation of the coating liquid 1 for the charge transport layer is changed to a polyarylate resin having structural units represented by (3-1) and (3-2) in a 5 / 5 ratio and having a weight-average molecular weight of 100,000, the coating liquid 3 for the charge transport layer is prepared in the same manner as the coating liquid 1 for the charge transport layer.

[0226] <Preparation of Coating Solution 4 for Charge Transport Layer>

[0227] Ten parts of a charge transport material represented by the following structural formula (CTM-4) and ten parts of polycarbonate (product name: Iupilon Z-400, manufactured by Mitsubishi Engineering-Plastics Corporation) were dissolved in a mixed solvent of 50 parts o-xylene / 25 parts THF. Thus, coating solution 4 for the charge transport layer was prepared.

[0228]

[0229] <Preparation of Coating Solution 5 for Charge Transport Layer>

[0230] Ten parts of a charge transport material, represented by the following structural formula (CTM-5), were used as the charge transport material.

[0231]

[0232] 10 parts of polycarbonate (product name: Iupilon Z-400, manufactured by Mitsubishi Engineering-Plastics Corporation) were dissolved in a mixed solvent of 25 parts o-xylene / 25 parts methyl benzoate / 25 parts dimethoxymethane. Thus, coating solution 5 for the charge transport layer was prepared.

[0233] <Preparation of Coating Solution 6 for Charge Transport Layer>

[0234] Except that in the preparation of coating liquid 1 for charge transport layer, 3.6 parts of triarylamine compound represented by (CTM-1) and 5.4 parts of triarylamine compound represented by (CTM-2) are changed to 9 parts of triarylamine compound represented by (CTM-1), coating liquid 6 for charge transport layer is prepared in the same manner as coating liquid 1 for charge transport layer.

[0235] <Preparation of Coating Solution 7 for Charge Transport Layer>

[0236] Except that the triarylamine compound represented by (CTM-1) is changed to the triarylamine compound represented by (CTM-2) in the preparation of the coating liquid 6 for the charge transport layer, the coating liquid 7 for the charge transport layer is prepared in the same manner as the coating liquid 6 for the charge transport layer.

[0237] <Preparation of Coating Solution 8 for Charge Transport Layer>

[0238] Except that the polycarbonate resin in the preparation of the coating liquid 4 for the charge transport layer is changed to a polyarylate resin having structural units represented by (3-1) and (3-2) in a 5 / 5 ratio and having a weight average molecular weight of 100,000, the coating liquid 8 for the charge transport layer is prepared in the same manner as the coating liquid 4 for the charge transport layer.

[0239] <Preparation of Coating Solution 9 for Charge Transport Layer>

[0240] Except that the polycarbonate resin in the preparation of the coating liquid 5 for the charge transport layer is changed to a polyarylate resin having structural units represented by (3-1) and (3-2) in a 5 / 5 ratio and having a weight-average molecular weight of 100,000, the coating liquid 9 for the charge transport layer is prepared in the same manner as the coating liquid 5 for the charge transport layer.

[0241] <Preparation of Coating Solution 10 for Charge Transport Layer>

[0242] Except that the polycarbonate resin in the preparation of the coating liquid 6 for the charge transport layer is changed to a polyarylate resin having structural units represented by (3-1) and (3-2) in a 5 / 5 ratio and having a weight-average molecular weight of 100,000, the coating liquid 10 for the charge transport layer is prepared in the same manner as the coating liquid 6 for the charge transport layer.

[0243] <Preparation of Coating Solution 11 for Charge Transport Layer>

[0244] Except that the polycarbonate resin is changed to a polyarylate resin having structural units represented by (3-1) and (3-2) in a 5 / 5 ratio and having a weight-average molecular weight of 100,000 in the preparation of the coating liquid 7 for the charge transport layer, the coating liquid 11 for the charge transport layer is prepared in the same manner as the coating liquid 7 for the charge transport layer.

[0245] <Production of Electrophotographic Photosensitive Components>

[0246] The support, conductive layer, primer, charge generation layer, and charge transport layer are produced using the following methods.

[0247] [Example 1]

[0248] <Support Body>

[0249] An aluminum cylinder with a diameter of 24 mm and a length of 257 mm is used as the support (cylindrical support).

[0250] <Conductive Layer>

[0251] The conductive layer is applied to the support by dip coating with coating liquid 1 to form a coating film, and the coating film is cured by heating at 150°C for 30 minutes to form a conductive layer with a thickness of 22 μm.

[0252] <Undercoat>

[0253] The base coating is applied to the conductive layer by dip coating with coating liquid 1 to form a coating film, and the coating film is cured by heating at 100°C for 10 minutes to form a base coating with a thickness of 1.2 μm.

[0254] <charge generation layer>

[0255] The charge generation layer is applied to the base layer by dip coating with coating liquid 1 to form a coating film, and the coating film is dried by heating at 100°C for 10 minutes to form a charge generation layer with a thickness of 0.20 μm.

[0256] <charge transport layer>

[0257] The charge transport layer is coated onto the charge generation layer by dip coating with coating liquid 1 to form a coating film, and the coating film is dried by heating at 120°C for 30 minutes to form a charge transport layer with a thickness of 21 μm.

[0258] [Examples 2 to 34]

[0259] Except for changing the coating liquid and thickness of the conductive layer, the coating liquid and thickness of the base layer, the coating liquid and thickness of the charge generation layer, and the coating liquid and thickness of the charge transport layer as shown in Table 1 in Example 1, the electrophotographic photosensitive components 2 to 34 are produced in the same manner as in Example 1.

[0260] Table 1

[0261]

[0262] [Comparative Example 1]

[0263] Electrophotographic photosensitive components are produced using the following methods.

[0264] <Support Body>

[0265] An aluminum cylinder with a diameter of 24 mm and a length of 257 mm is used as the support (cylindrical support).

[0266] <Conductive Layer>

[0267] The conductive layer is applied to the support by dip coating with coating liquid 2 to form a coating film, and the coating film is cured by heating at 160°C for 40 minutes to form a conductive layer with a thickness of 30 μm.

[0268] <Undercoat>

[0269] The base coating layer is applied to the conductive layer by dip coating with coating liquid 6, and the resulting coating film is polymerized by heating at 170°C for 20 minutes to form a base coating layer with a thickness of 0.7 μm.

[0270] <charge generation layer>

[0271] The charge generation layer is applied to the base layer by dip coating with coating liquid 2 to form a coating film, and the coating film is dried by heating at 100°C for 10 minutes to form a charge generation layer with a thickness of 0.20 μm.

[0272] <charge transport layer>

[0273] The charge transport layer is coated onto the charge generation layer by dip coating with coating liquid 2 to form a coating film, and the coating film is dried by heating at 120°C for 30 minutes to form a charge transport layer with a thickness of 21 μm.

[0274] [Comparative Example 2]

[0275] 50 parts of titanium dioxide powder coated with tin oxide containing 10% antimony oxide, 25 parts of methyl phenolic resin, 20 parts of methyl cellosolve, 5 parts of methanol, and 0.002 parts of silicone oil (polydimethylsiloxane-polyoxyethylene copolymer, average molecular weight: 3,000) were used in... Glass beads were dispersed in a sand mill for 2 hours to prepare a coating solution for the conductive layer.

[0276] The conductive layer is applied to the aluminum cylinder by dip coating with coating liquid 3. The length is 257 mm, and it is dried at 140°C for 30 minutes to form a conductive layer with a thickness of 15 μm.

[0277] The primer coating solution 7, obtained by dissolving 5 parts of 6-66-610-12 quaternary polyamide copolymer in a mixed solvent of 70 parts methanol and 25 parts butanol, was applied to the conductive layer by dip coating and dried to form a primer coating with a thickness of 0.7 μm.

[0278] Next, two parts of hydroxygallium phthalocyanine crystals exhibiting strong peaks at Bragg angles of 7.5°, 9.9°, 16.3°, 18.6°, 25.1°, and 28.3° in CuKα characteristic X-ray diffraction were mixed with a resin solution obtained by dissolving 1 part of polyvinyl butyral resin (product name: S-LEC BX-1, manufactured by Sekisui Chemical Co., Ltd.) in 19 parts of cyclohexanone. The mixture was dispersed in a sand mill using glass beads of 1 mm diameter for 3 hours to prepare a dispersion, and the glass beads were removed. The resulting liquid was diluted by adding 69 parts of cyclohexanone and 132 parts of ethyl acetate to prepare a charge-generating layer coating 3. The charge-generating layer coating 3 was applied to the base layer by dip coating and dried at 100°C for 10 minutes to form a charge-generating layer with a thickness of 0.12 μm.

[0279] Next, 8 parts of a charge-transporting material having a triphenylamine structure represented by structural formula (CTM-3) and 10 parts of a polyarylate resin (viscosity-average molecular weight: 100,000) having repeating structural units represented by the following structural formula (3-3) were dissolved in 60 parts of chlorobenzene to prepare a coating solution 12 for the charge-transporting layer. The coating solution 12 for the charge-transporting layer was coated onto the charge-generating layer by dip coating and dried at 120°C for 60 minutes to form a charge-transporting layer with a thickness of 11 μm. Thus, the electrophotographic photosensitive component of Comparative Example 2 was produced.

[0280]

[0281] [Comparative Example 3]

[0282] exist The following photosensitive layer is formed on an aluminum substrate to produce the electrophotographic photosensitive component of Comparative Example 3.

[0283] <Undercoat>

[0284] 30 parts of titanium chelate (TC-750: manufactured by Matsumoto Chemical Industry Co., Ltd.), 17 parts of silane coupling agent (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.), and 117 parts of 2-propanol were mixed to produce a primer coating liquid 8. The primer coating liquid 8 was applied to the above-mentioned cylindrical conductive support by dip coating and dried to produce a primer coating with a thickness of 1.0 μm.

[0285] <charge generation layer>

[0286] Sixty parts of Y-type titanium phthalocyanine (titanium phthalocyanine with a maximum peak at an X-ray diffraction angle of 2θ of 27.3° using Cu-Kα characteristic X-rays), 700 parts of silicone resin solution (KR5240, 15% xylene-butanol solution: manufactured by Shin-Etsu Chemical Co., Ltd.), and 1,610 parts of 2-butanone were mixed and dispersed using a sand mill for 10 hours to prepare coating solution 4 for the charge generation layer. This coating solution was then applied to the base layer by dip coating to form a charge generation layer with a dry film thickness of 0.2 μm.

[0287] <charge transport layer>

[0288] A coating solution 13 for the charge transport layer was prepared by mixing and dissolving 300 parts of charge transport material (4-methoxy-4′-(4-methyl-α-phenylstyryl)triphenylamine), 300 parts of bisphenol Z polycarbonate (Iupilon Z300: manufactured by Mitsubishi Gas Chemical Company, Inc.), 10 parts of tin oxide fine particles, and 2,000 parts of dioxolane. The coating solution 13 for the charge transport layer was applied to the charge generation layer by dip coating to form a charge transport layer with a dry film thickness of 20 μm.

[0289] [Comparative Example 4]

[0290] Except for the changes to the base coating and charge transport layer as described below, the electrophotographic photosensitive component of Comparative Example 4 was produced in the same manner as in Comparative Example 1.

[0291] <Undercoat>

[0292] The base coating is applied to the conductive layer by dip coating with coating liquid 2, and the resulting coating is polymerized by heating at 100°C for 10 minutes to form a base coating with a thickness of 0.8 μm.

[0293] <charge transport layer>

[0294] The charge transport layer was coated onto the charge generation layer by dip coating with coating liquid 2 at a lower coating speed than that of Comparative Example 1 to form a coating film, and the coating film was dried by heating at 120°C for 30 minutes to form a charge transport layer with a thickness of 17 μm.

[0295] [Comparative Example 5]

[0296] Except that the coating liquid used in the production of the charge generation layer was changed to coating liquid 1 for the charge generation layer and a charge generation layer with a thickness of 0.2 μm was formed, the electrophotographic photosensitive component of Comparative Example 5 was produced in the same manner as in Comparative Example 4.

[0297] [Comparative Example 6]

[0298] Type IV titanium phthalocyanine and polyvinyl butyral (BX-55, Sekisui Chemical Co., Ltd.) were mixed in a mixture of 2-butanone and cyclohexanone at a weight ratio of 45 / 55 to prepare a coating solution 5 for the charge-generating layer. Type IV titanium phthalocyanine exhibited strong peaks at Bragg angles 2θ of 9.6 ± 0.2°, 24.0 ± 0.2°, and 27.2 ± 0.2° in CuKα X-ray diffraction. This solution was used to impregnate an aluminum cylinder with a diameter of 24 mm and a length of 257 mm, followed by drying at 100 °C for 15 minutes to produce a charge-generating layer with a thickness of 0.25 μm.

[0299] 27.0 parts of p-(diethylamino)benzaldehyde diphenylhydrazone (DEH), 37.9 parts of bisphenol A (Bayer AG), and 0.48 parts of acetosol yellow were mixed in a solvent mixture of tetrahydrofuran and 1,4-dioxane to prepare coating liquid 14 for the charge transport layer. The above-mentioned charge generation layer was impregnated and coated using this liquid, and then dried at 100°C for 60 minutes to form the charge transport layer. Thus, the electrophotographic photosensitive component of Comparative Example 6 was produced.

[0300] [Comparative Example 7]

[0301] Except for the use of a coating solution 6 for the charge-generating layer obtained by mixing type IV titanium phthalocyanine and type I titanium phthalocyanine in a weight ratio of 67 / 33 instead of type IV titanium phthalocyanine in the production of the charge-generating layer, the electron-photographic photosensitive component of Comparative Example 7 was produced in the same manner as in Comparative Example 5. The type I titanium phthalocyanine exhibited strong peaks in the X-ray diffraction spectra using CuKα rays at Bragg angles 2θ of 7.6 ± 0.2°, 25.3 ± 0.2°, and 28.6 ± 0.2°.

[0302] [Comparative Example 8]

[0303] <Support Body>

[0304] An aluminum cylinder with a diameter of 24 mm and a length of 257 mm is used as the support (cylindrical support).

[0305] <Undercoat>

[0306] The base coating is applied to the conductive layer by dip coating with coating liquid 1 to form a coating film, and the coating film is cured by heating at 100°C for 10 minutes to form a base coating with a thickness of 1.2 μm.

[0307] <charge generation layer>

[0308] 0.45 parts of IUPILON 200, poly(4,4′-diphenyl)-1,1′-cyclohexane carbonate (PCZ-200, available from Mitsubishi Gas Chemical Company, Inc.), and 56 parts of tetrahydrofuran were added to a 4-ounce glass vial to prepare a dispersion for the charge-generating layer. 2.4 parts of hydroxygallium phthalocyanine V-type and 300 parts of stainless steel pellets, each with a diameter of 3.2 mm, were added to the above solution. The mixture was then placed in a ball mill for approximately 24 hours. Next, 2.25 parts of poly(4,4′-diphenyl-1,1′-cyclohexane carbonate) (PCZ-200) with a weight-average molecular weight of 20,000 were dissolved in 46.1 parts of tetrahydrofuran, and the solution was then added to the above hydroxygallium phthalocyanine slurry. Then, 300 parts of the obtained slurry and 450 parts of glass beads, each with a diameter of 0.9 mm, were placed in a sand mill (K-800, manufactured by Igarashi Machine Production Co., Ltd. (now IMEX Co., Ltd.), with a disc diameter of 70 mm and 5 discs) and dispersed for 10 minutes. In this case, the process was carried out at a disc rotation rate of 1,800 times per minute. The glass beads were removed from the resulting dispersion, thus preparing a coating liquid 7 for the charge generation layer. This liquid was applied to the aforementioned base layer by dip coating and dried at 125°C for 2 minutes to form a charge generation layer with a thickness of 0.7 μm.

[0309] <charge transport layer>

[0310] Five parts of a triarylamine compound represented by (CTM-2) and five parts of PCZ-400 (trademark) (a known polycarbonate resin with an average molecular weight of about 40,000 and commercially available from Mitsubishi Gas Chemical Company, Inc.) were dissolved in tetrahydrofuran to produce a coating solution 15 for a charge transport layer containing 34 wt% solids. The coating solution 15 was applied to the charge generation layer by dip coating to form a coating film, and the coating film was dried by heating at 120°C for 30 minutes to form a charge transport layer with a thickness of 30 μm. Thus, the electrophotographic photosensitive component of Comparative Example 8 was produced.

[0311] [Comparative Example 9]

[0312] 100 parts by weight of zinc oxide (average particle size: 70 nm, a sample manufactured by Tayca Corporation, specific surface area: 15 m²) were tested. 2The mixture was stirred and mixed with 500 parts by weight of toluene. 1.25 parts by weight of silane coupling agent (KBM603, manufactured by Shin-Etsu Chemical Co., Ltd.) was added, and the mixture was stirred for 2 hours. Subsequently, toluene was removed by vacuum distillation, and the residue was calcined at 150°C for 2 hours to provide a surface-treated zinc oxide pigment.

[0313] 38 parts by weight of a solution obtained by dissolving 60 parts by weight of surface-treated zinc oxide, 13.5 parts by weight of a curing agent (terminated isocyanate, Sumidur 3175, manufactured by Sumitomo Bayer Urethane Co., Ltd.), and 15 parts by weight of butyral resin (BM-1, manufactured by Sekisui Chemical Co., Ltd.) in 85 parts by weight of methyl ethyl ketone were mixed with 25 parts by weight of methyl ethyl ketone, and the mixture was used... Glass beads were dispersed in a sand mill for 2 hours to provide a dispersion. 0.005 parts by weight of dioctyltin dilaurate as a catalyst and 3.4 parts by weight of silicone resin particles (TOSPEARL 130, manufactured by GE Toshiba Silicone Co., Ltd.) were added to the resulting dispersion to provide a primer coating solution 9. This coating solution was applied to an aluminum substrate with a diameter of 24 mm and a length of 257 mm by dip coating and dried and cured at 170°C for 40 minutes to provide a primer coating with a thickness of 25 μm.

[0314] Next, a mixture consisting of 15 parts by mass of hydroxygallium phthalocyanine (used as a charge-generating material, having diffraction peaks at least at Bragg angles (2θ±0.2°) of 7.3°, 16.0°, 24.9°, and 28.0° in X-ray diffraction spectra using CuKα rays), 10 parts by mass of vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Union Carbide Corporation) used as an adhesive resin, and 200 parts by mass of n-butyl acetate was used in… Glass beads were dispersed in a sand mill for 4 hours to provide a dispersion. 175 parts by weight of n-butyl acetate and 180 parts by weight of methyl ethyl ketone were added to the resulting dispersion, and the mixture was stirred to provide a coating solution 8 for the charge-generating layer. This coating solution was applied to the base layer by dip coating and dried at room temperature to form a charge-generating layer with a thickness of 0.2 μm.

[0315] Next, 4 parts by weight of N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′]biphenyl-4,4′-diamine and 6 parts by weight of bisphenol Z polycarbonate resin (viscosity-average molecular weight: 40,000) were added and dissolved in 80 parts by weight of tetrahydrofuran to provide a coating solution 16 for the charge transport layer. This coating solution was applied to the charge generation layer by dip coating and dried at 115°C for 40 minutes to form a charge transport layer with a thickness of 30 μm. Thus, the electrophotographic photosensitive component of Comparative Example 9 was produced.

[0316] [Comparative Example 10]

[0317] Using a paint mixer, 5 parts of metal-free phthalocyanine, 100 parts of a hole transporter represented by structural formula (CTM-6), 30 parts of an electron transporter represented by structural formula (CTM-7), 100 parts of polycarbonate (product name: Iupilon Z-400, manufactured by Mitsubishi Engineering-Plastics Corporation), and 800 parts of tetrahydrofuran were mixed and dispersed to produce a coating solution 9 for a charge-generating layer. This coating solution was applied to an aluminum tube and then dried with hot air at 130°C for 30 minutes to form a charge-generating layer with a thickness of 38 μm. Thus, the electrophotographic photosensitive component of Comparative Example 10 was produced.

[0318]

[0319] [Comparative Example 11]

[0320] The outer circumference of an aluminum cylinder with a diameter of 24 mm and a length of 257 mm was cut along its circumference using a diamond bit to form a rough surface with a pitch of 100 μm and a depth of 7 μm.

[0321] Next, 1 part of a triazo pigment represented by the following structural formula (CGM-1), 0.5 parts of phenoxy resin (PKHH; manufactured by Union Carbide Corporation), and 0.5 parts of polyvinyl butyral resin (BX-1; manufactured by Sekisui Chemical Co., Ltd.) were dispersed with 500 parts of cyclohexanone for 24 hours using a sand mill. The resulting dispersion of the triazo compound was diluted with 500 parts of 1,4-dioxane to produce a coating solution 10 for a charge-generating layer. This coating solution was applied to an aluminum cylinder by dip coating and dried to form a charge-generating layer with a thickness of 0.2 μm.

[0322]

[0323] Next, 50 parts of a diamino compound represented by structural formula (CTM-8), 50 parts of bisphenol Z-type polycarbonate, 1.5 parts of a dicyano compound represented by structural formula (CTM-9), and 4 parts of di-tert-butylhydroxytoluene were dissolved in dichloromethane to produce a coating solution 17 for the charge transport layer. This coating solution was applied to the charge generation layer by dip coating and dried to form a charge transport layer with a thickness of 35 μm. Thus, the electrophotographic photosensitive component of Comparative Example 11 was produced.

[0324]

[0325] [Comparative Example 12]

[0326] Except for changing the coating liquid 1 for the charge generation layer to the coating liquid 5 for the charge generation layer and changing the thickness of the charge generation layer to 0.29 μm in Example 1, the electrophotographic photosensitive component of Comparative Example 12 was produced in the same manner as in Example 1.

[0327] [Comparative Example 13]

[0328] Except for changing the base coat coating liquid 1 to the base coat coating liquid 2 and changing the thickness of the base coat to 0.8 μm in the production of Comparative Example 12, the electrophotographic photosensitive component of Comparative Example 13 was produced in the same manner as in Comparative Example 12.

[0329] The thicknesses of the conductive layer coating liquid and the conductive layer, the base layer coating liquid and the base layer, the charge generation layer coating liquid and the charge generation layer, and the charge transport layer coating liquid and the charge transport layer in the production of each of the above Comparative Examples 1 to 13 are shown in Table 2.

[0330] Table 2

[0331]

[0332] [evaluate]

[0333] The photosensitive components of the above embodiments and comparative examples were evaluated as follows. The results are shown in Table 3.

[0334] [Measurement of EV curve]

[0335] The EV curve of each photosensitive element was measured according to the EV curve evaluation method for electrophotographic photosensitive elements described above. That is, when using... Figure 5 The measuring equipment was used according to the <Method for Measuring EV Curves> at a temperature of 23.5 [°C] and a relative humidity of 50 [%RH] and has an I-value. exp The horizontal axis and represent V exp In the graph of the vertical axis, when I in the graph exp =0.500 [μJ / cm2 V at that time exp From V = V r [V] represents I in the diagram. exp =0.000~0.030 [μJ / cm] 2 Within the range of S=I exp ·(V exp -V r S[V·μJ / cm] represents 2 The maximum value of ] is determined by S max [V·μJ / cm 2 ] indicates, and in the figure I exp =0.000~0.010 [μJ / cm] 2 Approximate straight line within the range of I exp =0.490~0.500 [μJ / cm 2 The amount of light I on the horizontal axis at the intersection of approximately straight lines within the range of ] i [μJ / cm 2 [and the potential V on the vertical axis] i The product of [V] is given by S i =I i ·(V i -V r )[V·μJ / cm 2 When represented by ], calculate S. i With S max The ratio AR = S i / S max .

[0336] <Methods for Measuring EV Curves>

[0337] (1): Set the surface potential of the electrophotographic photosensitive element to 0 [V].

[0338] (2): The electrophotographic photosensitive element is charged for 0.005 seconds so that the absolute value of its initial surface potential becomes V0[V].

[0339] (3): 0.02 seconds after the start of charging, the charged electrophotographic photosensitive component is continuously exposed to an atmosphere with a wavelength of 805 nm and an intensity of 25 mW / cm². 2 The light is emitted in seconds, thus achieving an exposure of I. exp [μJ / cm 2 ].

[0340] (4): 0.06 seconds after the start of charging, the absolute value of the surface potential of the electrophotographic photosensitive element after exposure is measured and determined by V. exp [V] indicates.

[0341] (5): At 0.001 [μJ / cm2 The interval of I will exp From 0.000 [μJ / cm 2 [Changed to 1.000 [μJ / cm]] 2 Simultaneously repeat operations (1) to (4) to obtain the corresponding I. exp V exp .

[0342] (6): In operations (1) to (5), in operation (3) t=0 and I exp =0.000[μJ / cm 2 V at that time exp [V] is specifically referred to as the electric potential V. d [V], and set V0[V] in operation (2) so that V d [V] takes the value of 300V.

[0343] S obtained by the above method max S i AR, VR max -V r I max LR max and V r As shown in Table 3.

[0344] [Area Gradation Image Evaluation]

[0345] A laser beam printer (product name: Color LaserJet Enterprise M653dn) manufactured by Hewlett-Packard Company was prepared as an evaluation electrophotographic device. The motor driving the photosensitive drum, etc., was modified to rotate at 100 rpm. Furthermore, the printer was modified to allow adjustment and measurement of the applied voltage of the charging roller, the developing voltage, and the pre-exposure and image exposure of the photosensitive element. Additionally, modifications were made to increase the spot diameter of the exposure laser (1 / e... 2 The diameter is changed to 50μm.

[0346] In addition, three processing boxes were prepared for each embodiment and comparative example. Each processing box was installed only on the magenta processing box station, thus enabling operation without installing the processing boxes for other colors (cyan, yellow, and black) on the main body of the laser beam printer.

[0347] In the image output, a magenta-colored processing cartridge containing the manufactured electrophotographic photosensitive element is mounted onto the main body of the laser beam printer, and the applied voltage of the charging roller is set to achieve a dark area potential of -350V under normal temperature and humidity conditions (temperature: 23°C, relative humidity: 50%). Subsequently, the applied light intensity is measured at 0.500 μJ / cm². 2 The surface potential of the image during exposure and determined by V rr [V] indicates that the surface potential becomes (-350-V) rr The image exposure at V is calculated as 5 times the light intensity of 1 / 2 [V], and then the image exposure for evaluation is set as 5 times that image exposure. Furthermore, the exposure potential (hereinafter referred to as "bright area potential") at the evaluation image exposure is determined by V. ll [V] indicates that the voltage is applied to evaluate the charging roller so that the dark area potential is taken through V. dd =(-350+V) ll The value calculated by [V]. V at this time. dd This is called the dark area potential for evaluation. Furthermore, the pre-exposure is set to three times the exposure of the evaluation image. For measuring the surface potential of the photosensitive element during potential setting, a potential probe (product name: model6000B-8, manufactured by Trek Japan) mounted at the developing position of the processing cartridge is used, along with a surface potentiometer (product name: model 344, manufactured by Trek Japan).

[0348] In the above method, the dark area potential and the exposure amount of the image for evaluation are set for each electrophotographic photosensitive component of the embodiments and comparative examples to be evaluated. Using such settings, the effect of residual surface potential (hereinafter referred to as "residual potential") that remains even after illumination with sufficiently strong light can be eliminated, thereby fixing the absolute value of the potential difference contrast between the dark area potential and the bright area potential of each electrophotographic photosensitive component at 350 [V]. Furthermore, the change in exposure potential under varying exposure amounts on the EV curve can be made uniform across all electrophotographic photosensitive components to be evaluated. Therefore, simulated grayscale can be evaluated with uniform digital grayscale across all electrophotographic photosensitive components to be evaluated.

[0349] Subsequently, the resolution of the output image was evaluated based on an area grayscale image with a resolution of 600 dpi and a line growth dither pattern with 300 lines.

[0350] For area grayscale images (halftone images), grayscale data is divided into 17 equal stages. In this case, grayscale is defined by assigning a value to each grayscale tone, assigning 16 to the darkest grayscale tone and 0 to the lightest grayscale tone.

[0351] In the obtained output images, the output images at each gray level were visually confirmed, and a rating was given according to the image results using the following criteria. Evaluation criteria A to C are defined as representing the effects of the present invention. The evaluation results are shown in Table 3.

[0352] A: For all gray levels from 1 to 15, the stagewise density change can be visually confirmed.

[0353] B: For grayscale values ​​of 2 to 14, the gradual change in concentration can be visually observed, but for any other grayscale values, the gradual change in concentration cannot be visually observed.

[0354] C: For grayscale values ​​of 3 to 12 or 4 to 13, or both, a gradual change in concentration can be visually observed, but for any other grayscale values, a gradual change in concentration cannot be visually observed.

[0355] D: Gradual concentration changes can only be visually confirmed for gray levels of 5 to 12 or a portion thereof.

[0356] Table 3

[0357]

[0358]

[0359] 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 accorded the broadest interpretation, thus covering all such modifications and equivalent structures and functions.

Claims

1. An electrophotographic photosensitive component, comprising: Support body; A charge-generating layer is formed on the support; and A charge transport layer is formed on the charge generation layer. Its characteristic is that the electrophotographic photosensitive element is an organic photosensitive element. The charge-generating layer comprises hydroxy gallium phthalocyanine pigment. The hydroxygallium phthalocyanine pigment comprises: The crystal structure exhibiting peaks at Bragg angles of 2θ of 7.4°±0.3° and 28.2°±0.3° in X-ray diffraction spectra using CuKα rays indicates a grain type; and N-methylformamide, The charge transport layer comprises a triarylamine compound represented by formula (CTM-1) and a triarylamine compound represented by formula (CTM-2) as charge transport substances: The electrophotographic photosensitive component further includes an undercoat layer formed between the support and the charge-generating layer. The base coating comprises: Polyamide resin; and Titanium oxide particles surface-treated with a compound represented by formula (1), and Wherein, when the ratio of the volume of the titanium oxide particles to the volume of the polyamide resin in the base coating is represented by "a" and the average primary particle size of the titanium oxide particles is represented by "b" in μm, a / b satisfies the following expression (A): 14.0 ≤ a / b ≤ 19.1 (A) In formula (1), R 1 represents a methyl group, an ethyl group, an acetyl group or a 2-methoxyethyl group, R 2 represents a hydrogen atom or a methyl group, m + n = 3, "m" represents an integer of 0 or more, and "n" represents an integer of 1 or more, with the proviso that when "n" represents 3, R 2 is not present, and The EV curves were obtained at 23.5°C and 50% RH using the following method and have an expression for I. exp The horizontal axis and represent V exp In the graph along the vertical axis, When I in the figure exp =0.500μJ / cm 2 V at time exp By V r express, In the figure I exp =0.000~0.030μJ / cm 2 Within the range of S=I exp (V exp -V r ) indicates that the maximum value of S is determined by S max express, In the figure I exp =0.000~0.010μJ / cm 2 Approximate straight line within the range of I exp =0.490~0.500μJ / cm 2 The light intensity I on the horizontal axis at the intersection of approximately straight lines within the range i With the potential V on the vertical axis i The product of S i =I i (V i -V r ) indicates, and S i With S max The value of the ratio S i / S max When represented by AR, The AR satisfies AR≤0.10, and The V r Satisfy V r ≤30: The method for measuring the EV curve is as follows: (1): Set the surface potential of the electrophotographic photosensitive component to 0V; (2): The electrophotographic photosensitive element is charged for 0.005 seconds so that the absolute value of the initial surface potential of the electrophotographic photosensitive element becomes V0; (3): 0.02 seconds after the start of charging, the charged electrophotographic photosensitive component is continuously exposed to an atmosphere with a wavelength of 805 nm and an intensity of 25 mW / cm². 2 The light "t" seconds, thus achieving an exposure of I. exp ; (4): 0.06 seconds after the start of charging, the absolute value of the surface potential of the electrophotographic photosensitive element after exposure is measured and determined by V. exp express; (5): At 0.001 μJ / cm 2 The interval will I exp From 0.000 μJ / cm 2 Change to 1.000 μJ / cm 2 Simultaneously repeat operations (1) to (4) to obtain the corresponding I. exp V exp ;and (6): In operations (1) to (5), in operation (3) t=0 and I exp =0.000μJ / cm 2 Time V exp Specifically called the charged potential V d And set V0 in operation (2) so that V d The value is 300V. Where V r V i V0, V exp V d The units are V, S, S max S i The unit is V μJ / cm 2 I i I exp The unit is μJ / cm 2 .

2. The electrophotographic photosensitive component according to claim 1, wherein AR satisfies AR≤0.

09.

3. The electrophotographic photosensitive component according to claim 1 or 2, wherein, When S becomes S max V at time exp and I exp V max and I max Indicates and (V) max -V r ) / I max By LR max When indicated, the LR max Satisfy LR max ≥2,000.

4. The electrophotographic photosensitive element according to claim 3, wherein the LR max Satisfy LR max ≥3,000.

5. A processing box, characterized in that, It integrally supports the electrophotographic photosensitive component according to any one of claims 1 to 4 and at least one unit selected from the group consisting of a charging unit, a developing unit and a cleaning unit, and the processing cartridge is detachably mounted to the body of the electrophotographic device.

6. 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 to 4.

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