Process cartridge

Abstract

The present invention relates to a process cartridge. A process cartridge detachably mounted to a main body of an electrophotographic apparatus, wherein a surface protective layer of an electrophotographic photosensitive member contains electrically conductive particles; a content of the electrically conductive particles is 20.0 to 70.0 vol% of the surface protective layer; a volume resistivity of the surface protective layer is 1.0 x 10 9 to 1.0 x 10 14 Ω·cm; toner particles have at least one multivalent metal element selected from the group consisting of aluminum, magnesium, calcium, and iron; and a total content of the multivalent metal elements in the toner particles is 0.10 to 1.25 μmol / g as measured by inductively coupled plasma atomic emission spectrometry (ICP-AES).

Description

Technical Field

[0001] This disclosure relates to processing cartridges used in copiers and printers employing electrophotographic and electrostatic recording methods. Background Technology

[0002] In recent years, there has been a growing demand for higher image quality in printers and copiers. Furthermore, due to the wide range of environments in which users operate, consistent image quality is required regardless of the environment.

[0003] In response to this requirement, toners manufactured via emulsion aggregation are frequently proposed due to their wide range of material selectivity and ease of controlling toner particle shape. In emulsion aggregation, a resin particle dispersion prepared by emulsion polymerization, forced emulsification, or phase-inversion emulsification, and a colorant dispersion in a solvent are prepared. These are then mixed to form aggregates with a size comparable to the toner particle size using an aggregator, and the aggregates are heated to fuse and coalesce, thereby producing the toner.

[0004] Multivalent metal ions are typically used as aggregators, and the presence of metal ions derived from the aggregator in the toner particles allows for the leakage of charge accumulated on the surface of the toner particles. This suppresses toner overcharging, especially in low-temperature, low-humidity environments where charge easily accumulates, and minimizes the adverse effects of toner development on non-printing areas of the image due to poor toner charging (hereinafter referred to as "hazing"). In contrast, in high-temperature, high-humidity environments with high atmospheric moisture content, charge leakage and reduced charge on the toner surface lead to hazing and problems with obtaining images with excellent grayscale. Excellent grayscale refers to the ability to clearly distinguish the differences in color intensity within an image. Color intensity is represented by increasing or decreasing the toner dosage per unit area on the image, and with low toner charge, the toner dosage developed on the electrophotographic photosensitive element (hereinafter also referred to as "photosensitive element") can be high or extremely low, making it difficult to distinguish subtle differences in color intensity within the image.

[0005] As a countermeasure to such problems, Japanese Patent Application Publication No. 2009-229495 proposes a processing cartridge that combines an emulsified aggregate toner with a photosensitive element having a surface protective layer (hereinafter also referred to as the "protective layer") containing specific conductive particles. In Japanese Patent Application Publication No. 2009-229495, image flow under high temperature and high humidity environments is improved by stabilizing the electrical properties of the photosensitive element and increasing its mechanical strength, and it is argued that such a solution is also effective in suppressing fogging.

[0006] However, according to the inventors' research, even using the configuration described in Japanese Patent Application Publication No. 2009-229495, it is impossible to improve the degradation of grayscale under high temperature and high humidity conditions. This is presumably because the electrical properties of the protective layer of the photosensitive element are unsuitable. To obtain images with excellent grayscale, it is believed that there is still room for improvement in the characteristics and content of the conductive particles in the protective layer.

[0007] Therefore, the purpose of this disclosure is to provide a processing box that suppresses fogging regardless of the usage environment and is able to form images with excellent grayscale. Summary of the Invention

[0008] The processing cartridge according to this disclosure is a processing cartridge detachably mounted to the main body of an electrophotographic device. The processing cartridge includes: an electrophotographic photosensitive component; and a developing unit having a toner storage section for containing toner and supplying toner to the surface of the electrophotographic photosensitive component. The electrophotographic photosensitive component has a conductive support and a photosensitive layer and a surface protective layer sequentially formed on the conductive support. The surface protective layer contains conductive particles; the content of the conductive particles is 20.0% by volume or more and 70.0% by volume or less of the total volume of the surface protective layer; and the volume resistivity of the surface protective layer is 1.0 × 10⁻⁶. 9 Ω·cm or more and 1.0×10 14 The toner contained in the toner storage compartment has toner particles containing a binder resin and external additives; the toner particles have at least one multivalent metal element selected from the group consisting of aluminum, magnesium, calcium and iron; and the total content of multivalent metal elements in the toner particles, as measured by inductively coupled plasma atomic emission spectrometry (ICP-AES), is 0.10 μmol / g or more and 1.25 μmol / g or less.

[0009] Further features of this disclosure will become apparent from the following description of exemplary embodiments, with reference to the accompanying drawings. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of a processing box used to evaluate toners in an embodiment.

[0011] Figure 2 A diagram illustrating an example of a comb electrode used to measure the volume resistivity of a photosensitive element according to the present disclosure.

[0012] Figure 3 An example of an image used to evaluate the grayscale of a processing box according to this disclosure.

[0013] Figure 4 STEM images of an example of niobium-containing titanium oxide used in the embodiments are shown.

[0014] Figure 5 This is a schematic diagram illustrating an example of niobium-containing titanium oxide used in the embodiments. Detailed Implementation

[0015] Preferred embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0016] In this disclosure, unless otherwise stated, the terms "XX and below YY" or "XX to YY" refer to a numerical range including the lower and upper limits as endpoints.

[0017] This disclosure will now be described in detail.

[0018] The inventors conducted detailed experiments on the following (1), (2), and (3) in a toner containing toner particles with polyvalent metal elements from the initial stage to the end of long-term continuous use.

[0019] (1) Excellent grayscale can be obtained under high temperature and high humidity conditions;

[0020] (2) It does not fog under high temperature and high humidity conditions; and

[0021] (3) It will not fog up due to overcharging in low temperature and low humidity environments.

[0022] The results showed that images with excellent grayscale that suppress fogging regardless of the usage environment can be formed and realized through a processing cartridge having a photosensitive element, a toner storage section containing toner, and a developing unit that supplies toner to the surface of the photosensitive element.

[0023] The photosensitive component has a conductive support and a photosensitive layer and a surface protective layer sequentially formed on the conductive support; the surface protective layer contains conductive particles; the content of conductive particles is more than 20.0% by volume and less than 70.0% by volume of the total volume of the surface protective layer; the volume resistivity of the surface protective layer is 1.0 × 10⁻⁶. 9 Ω·cm or more and 1.0×10 14 Below Ω·cm;

[0024] The toner contained in the toner storage section has toner particles containing a binder resin and external additives; the toner particles have at least one multivalent metal element selected from the group consisting of aluminum, magnesium, calcium and iron; and the total content of the multivalent metal element in the toner particles, as measured by inductively coupled plasma atomic emission spectrometry (ICP-AES), is 0.10 μmol / g or more and 1.25 μmol / g or less.

[0025] The reasons for the effects of this disclosure as described above are speculated to be as follows.

[0026] Grayscale of an image is represented by increasing or decreasing the amount of toner developed per unit area on the photosensitive element in the processing chamber, thereby creating differences in color intensity. The amount of toner developed is controlled by the potential of the electrostatic latent image formed on the surface of the photosensitive element and the charge of the toner. For excellent grayscale, it is important that the toner has a high charge and a sharp charge distribution. For example, in high-temperature and high-humidity environments with high moisture content in the air, the charge of the toner tends to decrease, and the amount of toner developed on the photosensitive element tends to increase, making it difficult to generate differences in color intensity in response to subtle potential differences in the electrostatic latent image. Furthermore, it becomes difficult to control the density, especially for low-density images such as halftone images, and when the potential of the electrostatic latent image drops below a certain value, the developability of the toner suddenly decreases, easily leading to drastically reduced image density.

[0027] The inventors have achieved this by including conductive particles in an appropriate amount in the protective layer on the surface of the photosensitive element and by controlling the volume resistivity of the protective layer, allowing a small portion of the charge on the surface of the photosensitive element to be injected into the toner during development. Furthermore, similarly, for the toner, the balance between charge injection and charge leakage is appropriately controlled by adjusting the amount of polyvalent metal elements present in the toner particles. Moreover, the inventors have discovered that the combination of these factors allows a small portion of the charge on the surface of the photosensitive element to be injected into the toner during development, resulting in a high charge level and a sharp charge distribution in the toner. This enables the production of a processing cartridge that can produce images with excellent grayscale regardless of the usage environment and suppress fogging even after prolonged use.

[0028] The photosensitive component according to this disclosure comprises a conductive support, a photosensitive layer, and a protective layer as a surface layer. The protective layer contains conductive particles, and the content of the conductive particles is 20.0% by volume or more and 70.0% by volume or less of the total volume of the protective layer. Furthermore, the surface protective layer is characterized by a volume resistivity of 1.0 × 10⁻⁶. 9 Ω·cm or more and 1.0×10 14 Below Ω·cm. Although the protective layer contains many conductive particles, it maintains a relatively high volume resistivity, which allows charge to be injected into the toner of this disclosure via the conductive particles while still ensuring charge retention.

[0029] A conductive particle content of less than 20.0% by volume reduces the charge injection capability of the toner disclosed herein, resulting in low charge of the toner during development and making it prone to grayscale reduction and fogging. On the other hand, a conductive particle content exceeding 70.0% by volume makes the protective layer itself brittle, making the surface of the photosensitive element prone to scratching over long-term use. This leads to a decrease in the charge uniformity of the photosensitive element, making it prone to grayscale reduction and fogging. More preferably, the conductive particle content is 40.0% by volume or more and 70.0% by volume or less in the protective layer.

[0030] Furthermore, the protective layer is characterized by a volume resistivity of 1.0 × 10⁻⁶. 9 Ω·cm or more and 1.0×10 14 Below Ω·cm. The volume resistivity of the protective layer is less than 1.0 × 10⁻⁶. 9 The volume resistivity of the protective layer drops too low (Ω·cm), making it difficult to maintain the potential and easily causing a decrease in grayscale level. The volume resistivity of the protective layer exceeds 1.0 × 10⁻⁶. 14 The resistance of the protective layer increases to an excessively high level (Ω·cm), severely degrading the charge transfer capability of the toner.

[0031] The volume resistivity of the protective layer is more preferably 1.0 × 10⁻⁶. 10 Ω·cm or more and 1.0×10 14 The volume resistivity of the protective layer can be controlled, for example, by the particle size of the conductive particles. The particle size, in terms of number-average particle size, is preferably 40 nm or more and 300 nm or less, and more preferably 100 nm or more and 250 nm or less. When the number-average particle size is less than 40 nm, the specific surface area of ​​the conductive particles becomes larger, and the adsorption of moisture near the conductive particles on the surface of the protective layer increases, which easily leads to a decrease in the volume resistivity of the protective layer. When the number-average particle size exceeds 300 nm, not only does the dispersion of the particles in the protective layer deteriorate, but the interfacial area with the binder resin also decreases, increasing the resistance at the interface and easily deteriorating charge injection properties.

[0032] Examples of conductive particles included in the protective layer include metal oxide particles such as titanium dioxide, zinc oxide, tin oxide, and indium oxide, with titanium dioxide being preferred. In particular, anatase-type titanium dioxide facilitates charge transfer within the protective layer, allowing for favorable charge injection. The anatase mineralization of the anatase-type titanium dioxide is preferably 90% or higher. The metal oxide particles can be doped with atoms such as niobium, phosphorus, and aluminum, or their oxides, with titanium dioxide particles containing niobium and having a structure that causes niobium to be unevenly distributed near the particle surface being particularly preferred. The uneven distribution of niobium near the surface allows for efficient charge transfer. More specifically, the titanium dioxide particles are those in which the concentration ratio calculated by measuring the niobium atom concentration / titanium atom concentration within 5% of the particle's maximum diameter from the particle surface is at least 2.0 times the concentration ratio of niobium atom concentration / titanium atom concentration at the particle's center. Note that the niobium atom concentration and titanium atom concentration are obtained by EDS analysis using a scanning transmission electron microscope (STEM). Figure 4 STEM images of examples of niobium-containing titanium dioxide particles used in embodiments of this disclosure are shown. As will be described in detail below, the niobium-containing titanium dioxide particles used in the embodiments are produced by coating the titanium dioxide particles to be nucleated with niobium-containing titanium dioxide and then calcining the coated nuclei. Therefore, it is presumed that the coated niobium-containing titanium dioxide is grown into niobium-doped titanium dioxide through so-called epitaxial growth along the crystal of the titanium dioxide nucleus. Figure 4 As shown, the niobium-containing titanium oxide produced in this way is controlled in a core-shell morphology, with a lower density near the surface compared to the density at the center of the particle.

[0033] Figure 4 STEM images in Figure 5 The diagram illustrates this schematically. In this type of niobium-containing titanium oxide particles, the niobium / titanium atom concentration ratio near the particle surface is greater than that at the particle center, and the niobium atoms are unevenly distributed near the particle surface. Specifically, the niobium / titanium atom concentration ratio within 5% of the particle's maximum diameter, measured from the particle surface, is more than 2.0 times that at the particle center. This ratio of more than 2.0 times facilitates charge movement within the protective layer and improves charge injection. A ratio less than 2.0 times makes charge transfer difficult.

[0034] exist Figure 5 In the figure, reference numeral 31 indicates the center of the conductive particle, reference numeral 32 indicates the vicinity of the surface of the conductive particle, reference numeral 33 indicates X-rays analyzing the center of the conductive particle, and reference numeral 34 indicates X-rays analyzing a position 5% of the particle diameter from the surface of the conductive particle.

[0035] The content of niobium atoms relative to the niobium-containing titanium oxide particles is preferably 0.5% by mass or more and 15.0% by mass or less, and more preferably 2.6% by mass or more and 10.0% by mass or less.

[0036] The following describes the toners according to this disclosure.

[0037] The toner according to this disclosure comprises toner particles containing a binder resin and external additives, and the toner particles contain at least one polyvalent metal element selected from the group consisting of aluminum, magnesium, calcium, and iron. Furthermore, the total content of the polyvalent metal element in the toner particles, as measured by inductively coupled plasma atomic emission spectrometry (ICP-AES), is characterized by being 0.10 μmol / g or more and 1.25 μmol / g or less.

[0038] The toner particles contain at least one polyvalent metal element selected from the group consisting of aluminum, magnesium, calcium, and iron as an injection site for injecting charge from the photosensitive element. The resistivity of each of these metal elements at 20°C is: aluminum 2.7 × 10⁻⁶. -8 Ω·m, calcium 4.2×10 -8 Ω·m, magnesium 4.5×10 -8 Ω·m and iron 9.7×10 -8 Ω·m (from "Chemistry Handbook, Fundamentals-II" (4th revised edition, published by the Chemical Society of Japan, Maruzen, 1993, p. 490)). The inventors have confirmed that by including these metallic elements in appropriate amounts in the toner, these metallic elements exhibit stable charge injection and charge retention properties. Although not used in the toner according to this disclosure, for reference, copper (1.7 × 10⁻⁶) is a metallic element with low resistance. -8 Ω·m and silver 1.6×10 -8 Ω·m (from "Chemistry Handbook, Fundamentals-II" (4th revised edition, published by the Chemical Society of Japan, Maruzen, 1993, p. 490)).

[0039] The combination of at least one polyvalent metal element selected from the group consisting of aluminum, magnesium, calcium, and iron in the toner particles at a content of 0.10 μmol / g or more and 1.25 μmol / g or less with the photosensitive element of this disclosure allows for the injection of charge from the photosensitive element to the toner, enabling the acquisition of images with excellent grayscale. When the content of the polyvalent metal element is less than 0.10 μmol / g, the charge injection is significantly reduced, thereby failing to impart charge to the toner and failing to obtain excellent grayscale. Furthermore, the toner is prone to over-charge, which can easily lead to a broadening of the charge distribution of the toner under low temperature and low humidity conditions, resulting in fogging. When the content of the polyvalent metal element exceeds 1.25 μmol / g, the charge injection is excellent; however, conversely, the charge is prone to leakage, easily causing grayscale degradation and fogging.

[0040] More specifically, the content of each of the aforementioned polyvalent metal elements is 0.50 μmol / g or less for aluminum, and more preferably 0.10 μmol / g or more but 0.32 μmol / g or less. For magnesium, it is 0.80 μmol / g or less; for calcium, it is 0.90 μmol / g or less; and for iron, it is 1.25 μmol / g or less. The total content of these four polyvalent metal elements is preferably 0.10 μmol / g or more but 1.25 μmol / g or less. The reason why the preferred content range of each polyvalent metal element varies depending on the substance is related to the resistivity of the metal. Among the above, aluminum has low resistivity and exhibits excellent incorporation properties even in small quantities, which is preferred.

[0041] Polyvalent metal elements preferably exist in a dispersed form on the surface and inside the toner particles. The presence of polyvalent metal elements inside the toner particles causes the charge imparted to the surface of the toner particles to accumulate internally. When, for example, metal oxide particles are added externally to the toner particles, so that the polyvalent metal elements are present only on the surface of the toner particles, the injected charge leaks through components such as the toner carrier due to extremely high leakage, making it difficult to achieve the desired effect. Furthermore, with prolonged use, external additives may embed into or detach from the surface of the toner, causing fluctuations in the toner's charge characteristics and making it difficult to obtain images of stable quality.

[0042] The preferred method for containing multivalent metal elements within toner particles is to produce the toner particles via an emulsion aggregation method and to contain the multivalent metal elements within the particles via an aqueous medium. The emulsion aggregation method incorporates metal elements that have undergone ionization in an aqueous medium into the toner particles, thereby enabling uniform dispersion of the metal elements. Furthermore, in emulsion-aggregated toners, carboxyl groups are typically present in the molecular chains constituting the binder resin. Metal ions added as aggregators form coordination bonds with the carboxyl groups, allowing for the formation of excellent conductive pathways on the fine resin particles. In this case, trivalent aluminum can coordinate with the carboxyl groups in a smaller amount than divalent magnesium and calcium, and iron, which can have mixed valence states, and exhibits superior charge injection properties.

[0043] The toners according to this disclosure may contain waxes. Known substances can be used as waxes, and examples include: aliphatic hydrocarbon waxes, such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; oxides of aliphatic hydrocarbon waxes, such as oxidized polyethylene wax or its block copolymers; waxes grafted with aliphatic hydrocarbon waxes and vinyl monomers such as styrene or acrylic acid; and saturated fatty acid ester compounds, such as stearate, behenate, dibehenate sebacic acid, distearate, octadecanoate, nonanediol dibehenate, ethylene glycol distearate, ethylene glycol dibehenate, butylene glycol dibehenate, butylene glycol distearate, pentaerythritol tetrabehenate, and dipentaerythritol hexastearate. The ester compounds, due to their higher polarity and lower electrical resistance compared to hydrocarbon waxes, have the ability to assist in charge injection into the toner particles.

[0044] The composition of the photosensitive element according to this disclosure will be described in detail below.

[0045] <Protective Layer>

[0046] When the protective layer is a surface layer, conductive particles according to this disclosure are contained on the surface of the protective layer. The protective layer may comprise a polymer or resin of a compound having polymerizable functional groups. Examples of polymerizable functional groups 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, carbon-carbon double bond groups, alkoxysilyl groups, and silanol groups. Monomers with charge-transporting capabilities may be used as compounds having polymerizable functional groups. Compounds having polymerizable functional groups may have charge-transporting structures as well as chain polymerizable functional groups.

[0047] Examples of resins include polyester resins, acrylic resins, phenoxy resins, polycarbonate resins, polystyrene resins, phenolic resins, melamine resins, and epoxy resins. Polycarbonate resins, polyester resins, and acrylic resins are preferred. 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 transport capabilities can be used as monomers with polymerizable functional groups.

[0048] The protective layer can be formed by preparing a coating solution containing the above-mentioned materials and solvents, forming the coating film on the photosensitive layer, and drying and / or curing it. The solvents used in the coating solution include alcohol-based solvents, ketone-based solvents, ether-based solvents, sulfoxide-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents.

[0049] The protective layer may contain additives such as antioxidants, UV absorbers, plasticizers, leveling agents, slip-improving agents, or abrasion resistance enhancers. Specifically, these 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.

[0050] The average thickness of the protective layer is preferably 0.2 μm or more and 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less.

[0051] The material and particle size of the conductive particles contained in the protective layer are as described above.

[0052] <Conductive support>

[0053] The photosensitive component according to this disclosure includes a conductive support body with conductivity. Examples of the shape of the support body include, for example, cylindrical, strip, and sheet shapes, with a cylindrical support body being preferred. Furthermore, the surface of the support body can be subjected to electrochemical treatments such as anodizing, sandblasting, or machining. Metals, resins, and glass are preferred as materials for the support body. Examples of metals include aluminum, iron, nickel, copper, gold, stainless steel, and their alloys. Aluminum support bodies are preferred. Furthermore, it is preferable to impart conductivity to the resin and glass by treatments such as mixing the resin and glass with a conductive material or coating them with a conductive material.

[0054] <Conductive Layer>

[0055] In the photosensitive component according to this disclosure, a conductive layer can be provided on a support. The conductive layer can shield scratches and irregularities on the surface of the support and control the reflection of light on the surface of the support. The conductive layer preferably comprises conductive particles and resin. Examples of conductive particles include metal oxides, metals, and carbon black. 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 preferably used as conductive particles, and titanium oxide, tin oxide, and zinc oxide are particularly preferred.

[0056] When using metal oxides 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 niobium, phosphorus, aluminum, or their oxides. Particularly preferred are metal oxides in which niobium atoms are unevenly distributed on or near the surface of the titanium oxide particles.

[0057] Furthermore, when using metal oxides as conductive particles, the number-average particle size of the metal oxides is preferably 1 nm or more and 500 nm or less, and more preferably 3 nm or more and 400 nm or less.

[0058] Examples of resins include polyester resins, polycarbonate resins, polyvinyl acetal resins, acrylic resins, silicone resins, epoxy resins, melamine resins, polyurethane resins, phenolic resins, and alkyd resins. Furthermore, the conductive layer may further comprise silicone oil, resin particles, and masking agents such as titanium dioxide.

[0059] A conductive layer can be formed by preparing a coating solution containing the aforementioned materials and solvents, forming the coating on a support, and drying it. Examples of solvents used in the coating solution include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. Methods for dispersing conductive particles in the coating solution for the conductive layer include methods using paint agitators, sand mills, ball mills, and high-speed liquid impact dispersers.

[0060] The average thickness of the conductive layer is preferably 1 μm or more and 40 μm or less, and particularly preferably 3 μm or more and 30 μm or less.

[0061] <Undercoat>

[0062] In the photosensitive component of this disclosure, a base coating can be provided on a support or conductive layer. The provided base coating improves interlayer adhesion and can impart charge injection prevention functionality. The base coating preferably comprises a resin. Furthermore, the base coating can be formed into a cured film by polymerizing a composition comprising monomers having polymerizable functional groups.

[0063] 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.

[0064] 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.

[0065] Furthermore, to improve electrical properties, the base coating may further include electron transport materials, metal oxides, metals, and conductive polymers. Among these, electron transport materials and metal oxides are preferred.

[0066] Examples of electron transport materials include quinone compounds, imide compounds, benzimidazole compounds, cyclopentadiene compounds, fluorenone compounds, xanthonesone compounds, benzophenone compounds, cyanovinyl compounds, aryl halogen compounds, thiophene compounds, and boron-containing compounds. The undercoat can be formed into a cured film by using an electron transport material with polymerizable functional groups as the electron transport material and copolymerizing it with monomers having polymerizable functional groups as described above.

[0067] Metal oxides include indium tin oxide, tin oxide, indium oxide, titanium oxide, zinc oxide, aluminum oxide, and silicon dioxide. Metals include gold, silver, and aluminum.

[0068] The metal oxide particles contained in the undercoat can be surface-treated using surface treatment agents such as silane coupling agents. Methods for surface-treating metal oxide particles generally employ these approaches, including, for example, dry and wet methods.

[0069] The dry method is as follows: while stirring the metal oxide particles in a high-speed mixer such as a Henschel mixer, an aqueous solution of alcohol, organic solvent, or aqueous solution containing a surface treatment agent is added to uniformly disperse the mixture, which is then dried.

[0070] In addition, the wet method involves stirring the metal oxide particles and surface treatment agent in a solvent, or dispersing the mixture using a sand mill with glass beads, etc. After dispersion, the solvent is removed by filtration or vacuum distillation. After removing the solvent, calcination is preferably carried out at 100°C or higher.

[0071] The base coating may further contain additives and may include, for example, metal powders such as aluminum, conductive materials such as carbon black, and known substances such as charge transport substances, metal chelating compounds, and organometallic compounds.

[0072] Examples of charge-transporting substances include quinone compounds, imide compounds, benzimidazole compounds, cyclopentadiene compounds, fluorenone compounds, xanthonesone compounds, benzophenone compounds, cyanovinyl compounds, aryl halogen compounds, thiophene compounds, and boron-containing compounds. Charge-transporting substances with polymerizable functional groups can be used as charge-transporting substances and copolymerized with the aforementioned monomers having polymerizable functional groups to form a cured film as a base coating.

[0073] The base coating can be formed by preparing a coating liquid containing the above-mentioned materials and solvents, forming the coating on a support or conductive layer, and drying and / or curing it.

[0074] Examples of solvents used in coating solutions for primer layers include organic solvents such as alcohols, sulfoxides, ketones, ethers, esters, aliphatic halogenated hydrocarbons, and aromatic compounds. In this disclosure, alcohol-based and ketone-based solvents are preferred.

[0075] Dispersion methods for preparing coating liquids for primer coatings include methods using homogenizers, ultrasonic dispersers, ball mills, sand mills, roller mills, vibratory mills, grinders, and liquid collision type high-speed dispersers.

[0076] The average thickness of the base coating is preferably 0.1 μm or more and 10 μm or less, and more preferably 0.1 μm or more and 5 μm or less.

[0077] <Photosensitive layer>

[0078] The photosensitive layer of the photosensitive component according to this disclosure is mainly classified into (1) a stacked photosensitive layer and (2) a single-layer photosensitive layer. The stacked photosensitive layer (1) is a photosensitive layer having a charge-generating layer containing a charge-generating substance and a charge-transporting layer containing a charge-transporting substance. The single-layer photosensitive layer (2) is a photosensitive layer containing both a charge-generating substance and a charge-transporting substance.

[0079] (1) Layered photosensitive layer

[0080] The stacked photosensitive layer has a charge generation layer and a charge transport layer.

[0081] (1-1) Charge generation layer

[0082] The charge-generating layer preferably comprises a charge-generating substance and a resin.

[0083] Examples of charge-generating substances include azo pigments, perylene pigments, polycyclic quinone pigments, indigo pigments, and phthalocyanine pigments. Among these, azo pigments and phthalocyanine pigments are preferred. Of the phthalocyanine pigments, titanium dioxide phthalocyanine pigments, gallium chloride phthalocyanine pigments, and hydroxy gallium phthalocyanine pigments are preferred.

[0084] The content of charge-generating material in the charge-generating layer is preferably 40% or more and 85% or less of the total mass of the charge-generating layer, and more preferably 60% or more and 80% or less of the total mass of the charge-generating layer.

[0085] The resins include polyester resins, polycarbonate resins, polyvinyl alcohol acetal resins, polyvinyl alcohol butyral resins, acrylic resins, silicone resins, epoxy resins, melamine resins, polyurethane resins, phenolic resins, polyvinyl alcohol resins, cellulose resins, polystyrene resins, polyvinyl acetate resins, and polyvinyl chloride resins. Among these, polyvinyl alcohol butyral resin is preferred.

[0086] Furthermore, the charge-generating layer may further contain additives such as antioxidants and ultraviolet absorbers. Specifically, these include hindered phenolic compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, and benzophenone compounds.

[0087] The charge-generating layer can be formed by preparing a coating solution containing the aforementioned materials and solvents, forming the coating film on a support, conductive layer, or primer layer, and then drying it. The solvents used in the coating solution include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents.

[0088] The average thickness of the charge generation layer is preferably 0.1 μm or more and 1 μm or less, and more preferably 0.15 μm or more and 0.4 μm or less.

[0089] (1-2) Charge transport layer

[0090] The charge transport layer preferably comprises a charge transport material and a resin.

[0091] 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 these substances. Among these, triarylamine compounds and benzidine compounds are preferred.

[0092] 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, and more preferably 30% by mass or more and 55% by mass or less.

[0093] The 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.

[0094] The ratio (mass ratio) of charge transport material to resin is preferably 4:10 to 20:10, and more preferably 5:10 to 12:10.

[0095] In addition, the charge transport layer may also contain additives such as antioxidants, ultraviolet absorbers, plasticizers, leveling agents, slip-improving agents, and abrasion resistance improvers. Specifically, these 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.

[0096] The charge transport layer can be formed by preparing a coating solution containing the above-described materials and solvents, forming the coating film on the charge generation layer, and drying it. The solvents used in the coating solution include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. Among these solvents, ether-based solvents or aromatic hydrocarbon-based solvents are preferred.

[0097] The average thickness of the charge transport layer is preferably 3 μm or more and 50 μm or less, more preferably 5 μm or more and 40 μm or less, and particularly preferably 10 μm or more and 30 μm or less.

[0098] (2) Single-layer photosensitive layer

[0099] A single-layer photosensitive layer can be formed by preparing a coating solution for the photosensitive layer containing a charge-generating substance, a charge-transporting substance, a resin, and a solvent, forming the coating film on a support, a conductive layer, or a base layer, and then drying it. The charge-generating substance, the charge-transporting substance, and the resin are the same as those in the examples of the substances in "(1) laminated photosensitive layer" above.

[0100] The binder resin, wax as a release agent, colorant, charge control agent and external additives constituting the toner of this disclosure will be described in detail below.

[0101] <Adhesive Resin>

[0102] There are no particular limitations on the binder resin used in the toner according to this disclosure, and known binder resins can be used, with vinyl resins and polyester resins being preferred. Examples of vinyl resins, polyester resins, and other binder resins include the following resins or polymers.

[0103] Examples include: homopolymers of styrene and its substituted products, such as polystyrene and polyvinyl toluene; styrene-based copolymers, such as styrene-propylene copolymers, styrene-vinyl toluene copolymers, styrene-vinyl naphthalene copolymers, styrene-methyl acrylate copolymers, styrene-ethyl acrylate copolymers, styrene-butyl acrylate copolymers, styrene-octyl acrylate copolymers, styrene-dimethylaminoethyl acrylate copolymers, styrene-methyl methacrylate copolymers, styrene-ethyl methacrylate copolymers, styrene-butyl methacrylate copolymers, styrene-vinyl methyl ether copolymers, styrene-vinyl ethyl ether copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resins, polyamide resins, epoxy resins, polyacrylic resins, rosin, modified rosin, terpene resins, phenolic resins, aliphatic or alicyclic hydrocarbon resins, and aromatic petroleum resins. These adhesive resins can be used alone or in mixtures. Preferably, they are styrene-based copolymers.

[0104] As mentioned above, these carboxyl-containing binder resins are preferably coordinated with polyvalent metal ions to form excellent conductive pathways.

[0105] Examples of polymerizable monomers containing a carboxyl group include: acrylic acid, methacrylic acid; α-alkyl or β-alkyl derivatives of acrylic acid or methacrylic acid, such as α-ethylacrylic acid and crotonic acid; unsaturated dicarboxylic acids, such as fumaric acid, maleic acid, citracic acid and itaconic acid; and unsaturated dicarboxylic acid monoester derivatives, such as monoacryloyloxyethyl succinate, monoacryloyloxyethylene succinate, monoacryloyloxyethyl phthalate, and monomethacryloyloxyethyl phthalate.

[0106] Polyester resins that have undergone condensation polymerization can be used with the carboxylic acid and alcohol components listed below.

[0107] Examples of carboxylic acid components include terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid, cyclohexanedicarboxylic acid, and trimellitic acid. Alcohol components include bisphenol A, hydrogenated bisphenol, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, glycerol, trimethylolpropane, and pentaerythritol.

[0108] In addition, the polyester resin can also be a polyester resin containing urea groups. Preferably, the polyester resin is a polyester resin with uncapped carboxyl groups at the ends, for example.

[0109] Wax

[0110] The colorant according to this disclosure may contain wax as a release agent. Suitable waxes are as described above. The wax content is 5.0 parts by weight or more and 20.0 parts by weight or less relative to 100.0 parts by weight of the adhesive resin or the polymerizable monomer used to produce the adhesive resin.

[0111] <Coloring agent>

[0112] There are no particular restrictions on the colorant, and any known colorant can be used.

[0113] As yellow pigments, condensed azo compounds such as iron oxide yellow, lapu yellow, naphthol yellow S, Hansa yellow G, Hansa yellow 10G, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, and tartrate yellow lake, as well as isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allyl amide compounds are used. Specifically, these include the following:

[0114] CI Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 155, 168, 180, 185 and 193.

[0115] Red pigments include, for example, condensed azo compounds such as red iron oxide, permanent red 4R, lithol red, pyrazolone red, calcium salt of epirubicin, lake red C, lake red D, bright carmine 6B, bright carmine 3B, eosin lake, rhodamine lake B, alizarin lake, etc.; diketylpyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindole compounds, and perylene compounds. Specifically, they include the following: CI Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254.

[0116] Blue pigments include, for example, copper phthalocyanine compounds and their derivatives such as Basic Blue Lake, Victoria Blue Lake, Phthalocyanine Blue, Metal-free Phthalocyanine Blue, Phthalocyanine Blue Partial Chloride, Sky Blue, and Indanthrene Blue BG, as well as anthraquinone compounds and basic dye lake compounds. Specifically, they include the following: CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66.

[0117] Black pigments include carbon black, aniline black, non-magnetic ferrites, magnetite, and those tinted to black using the above-mentioned yellow, red, and blue colorants. These colorants can be used alone, in mixtures, or even in solid solutions.

[0118] If necessary, the colorant can be surface-treated with a substance that does not hinder polymerization. Note that the content of the colorant is 3.0 parts by weight or more and 15.0 parts by weight or less relative to 100.0 parts by weight of the binder resin or the polymerizable monomer that produces the binder resin.

[0119] <charge control agent>

[0120] The toner according to this disclosure may contain a charge control agent. Any known charge control agent can be used. A charge control agent capable of rapidly charging and maintaining a constant and stable charge is preferred. Furthermore, in the case of producing toner particles by direct polymerization, a charge control agent with low polymerization inhibition and substantially insoluble in aqueous media is preferred. Charge control agents for controlling the toner particles to be negatively charged include those listed below.

[0121] Organometallic compounds and chelates include monoazo metal compounds, acetylacetone metal compounds, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, and hydroxycarboxylic or dicarboxylic acid metal compounds. Other organometallic compounds and chelates include aromatic hydroxycarboxylic acids, aromatic monocarboxylic acids and aromatic polycarboxylic acids and their metal salts, acid anhydrides or esters, and phenol derivatives such as bisphenol. Additionally, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphtholic acid compounds, boron compounds, quaternary ammonium salts, and calixarenes are also included.

[0122] These charge control agents may be included alone or in combination of two or more. The amount of charge control agent added is more than 0.01 parts by weight and less than 10.0 parts by weight relative to 100.0 parts by weight of adhesive resin.

[0123] <External Additives>

[0124] For purposes such as improving flowability, chargeability, and adhesion, the toner according to this disclosure may contain external additives.

[0125] Examples of external additives include inorganic microparticles such as silica microparticles, alumina microparticles, and titanium dioxide microparticles. They can be used alone or in combination of two or more of them. Preferably, these inorganic microparticles are surface-treated with silane coupling agents, titanium coupling agents, higher fatty acids, or silicone oils to improve heat resistance and environmental stability.

[0126] The preferred BET specific surface area of ​​the external additive is 10.0 m². 2 / g or more and 450.0m 2 / g or less. The BET specific surface area is determined using the BET method (preferably the BET multi-point method) and the low-temperature gas adsorption method utilizing dynamic constant pressure. The BET specific surface area (m²) is calculated by adsorbing nitrogen gas onto the sample surface using, for example, a specific surface area measuring device (product name: Gemini 2375Ver.5.0, manufactured by Shimadzu Corporation) and measuring the BET specific surface area using the BET multi-point method. 2 / g).

[0127] The amount of these various external additives is preferably 0.05 parts by weight or more and 5.0 parts by weight or less relative to 100.0 parts by weight of colorant particles. The types and amounts of external additives can be appropriately selected, as long as they do not impair the effects of this disclosure.

[0128] <Production Method of Colorant Granules>

[0129] The production of toner particles can be carried out using known methods, including mixing and pulverizing and wet production methods. Wet production methods are preferred in terms of particle size uniformity and shape control. Examples of wet production methods include suspension polymerization, dissolution suspension polymerization, emulsion polymerization, and emulsion polymerization, with emulsion polymerization being more preferred. That is, toner particles are preferably emulsion-polymerized toner particles. This is because toners facilitate the ionization of polyvalent metal elements in aqueous media, and also because toner particles readily incorporate polyvalent metal elements during binder resin aggregation.

[0130] In the emulsification-aggregation method, toner particles are produced after the resin fine particles undergo emulsification, aggregation, melting, cooling, and washing processes. Furthermore, if desired, a shell-forming process can be added after the cooling process to produce core-shell toners.

[0131] • Emulsification process of fine resin particles

[0132] Resin fine particles, mainly composed of binder resin, can be prepared using known methods. For example, a resin particle dispersion can be prepared by dissolving the binder resin in an organic solvent and adding the mixture to an aqueous medium, dispersing the particles with a surfactant and a polymeric electrolyte in the aqueous medium using a disperser such as a homogenizer, and then removing the solvent by heating or reducing pressure. Any organic solvent can be used to dissolve the resin, and tetrahydrofuran, ethyl acetate, or chloroform are preferred from the viewpoint of their high solubility.

[0133] From an environmental impact perspective, it is preferable to add the aforementioned resins, surfactants, and alkalis to the aqueous medium to emulsify and disperse them in an aqueous medium that is substantially free of organic solvents by means of a dispersant that applies high-speed shear force, such as CLEARMIX, a homogenizer, or a homogenizer.

[0134] There are no particular restrictions on the surfactants used in emulsification, and they include, for example, the following: anionic surfactants, such as sulfate-based surfactants, sulfonate-based surfactants, carboxylate-based surfactants, phosphate-based surfactants, and soap-based surfactants; cationic surfactants, such as amine-based and quaternary ammonium-based surfactants; and nonionic surfactants, such as polyethylene glycol-based surfactants, alkylphenol ethylene oxide adduct-based surfactants, and polyol-based surfactants. A surfactant may be used alone, or two or more may be used in combination.

[0135] The median particle size based on volume distribution of the resin fine particles is preferably 0.05 to 1.0 μm, and more preferably 0.05 to 0.4 μm. Toner particles with a median particle size of 4.0 to 7.0 μm are readily obtained with diameters below 1.0 μm, which is the appropriate median particle size based on volume distribution for toner particles. The median particle size based on volume distribution can be measured using a dynamic light scattering particle size analyzer (NANOTRAC UPA-EX1 50, manufactured by Nikkiso Co., Ltd.).

[0136] • Aggregation process

[0137] If necessary, the aggregation process involves mixing the above-mentioned resin fine particles, colorant particles, and wax particles to prepare a mixed solution, and then aggregating the particles contained in the prepared mixed solution to form aggregates.

[0138] As agglomerating agents, in addition to surfactants with polarity opposite to the aforementioned surfactants, inorganic salts and inorganic metal salts with a valence of divalent or higher can also be suitably used. In particular, inorganic metal salts can be ionized by adding a polyvalent metal element to an aqueous medium and readily form coordination bonds with the carboxyl groups contained in the binder resin. This makes it easy to control aggregation and the charge of the toner. Preferred examples of inorganic metal salts include calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, ferric chloride, aluminum chloride, or aluminum sulfate, as well as inorganic metal salt polymers such as polyferric chloride, polyaluminum chloride, and polyaluminum hydroxide. Trivalent aluminum salts and their polymers are particularly suitable. Generally, to obtain a sharper particle size distribution, the inorganic metal salt is preferably divalent rather than monovalent, and more preferably trivalent or higher than divalent.

[0139] There are no particular restrictions on the addition of the agglomerating agent, but it is preferred to add it at 25 to 35°C, followed by heating and raising the temperature to below the glass transition temperature (Tg) of the resin particles. Mixing at a temperature below Tg inhibits the fusion between resin particles and allows aggregation to proceed in a stable state. As a result, the metal element derived from the agglomerating agent can uniformly form coordination bonds with the carboxyl groups in the resin. The above mixing can be carried out using known mixing equipment such as a homogenizer or mixer.

[0140] The weight-average particle size of the aggregates formed here is not particularly limited and is advantageously controlled to be between 4.0 μm and 7.0 μm, so as to be substantially the same as the toner particles to be obtained. For example, this control can be easily achieved, for instance, by appropriately setting or changing the temperature and the stirring conditions during the addition and mixing of the aforementioned agglomerating agents. Note that the particle size distribution of the toner particles can be measured according to the Coulter method using a particle size distribution analyzer (Coulter Multisizer III manufactured by Beckman Coulter, Inc.).

[0141] · Welding process

[0142] The fusion process involves heating and fusing the aggregates above the glass transition temperature (Tg) of the resin to produce particles with smooth aggregate surfaces. Prior to a fusion process, chelating agents, pH adjusters, or surfactants may be appropriately added to prevent the fusion of toner particles.

[0143] Examples of chelating agents include the following: ethylenediaminetetraacetic acid (EDTA) and its alkali metal salts such as Na salt, sodium gluconate, sodium tartrate, potassium citrate and sodium citrate, nitrotriacetic acid (NTA) salts, and many water-soluble polymers (polymer electrolytes) containing both COOH and OH functional groups.

[0144] The heating temperature is preferably between the glass transition temperature (Tg) of the resin contained in the aggregate and the temperature at which the resin thermally decomposes. Regarding the heating and fusion time, the higher the heating temperature, the shorter the heating time, and the lower the heating temperature, the longer the required time. That is, the heating and fusion time depends on the heating temperature and cannot be uniformly specified, but it typically ranges from 10 minutes to 10 hours.

[0145] Cooling process

[0146] The cooling process involves cooling the aqueous medium containing the aforementioned particles to a temperature below the glass transition temperature (Tg) of the resin used. Failure to cool it to a temperature below Tg may result in the formation of coarse particles. The specific cooling rate is 0.1 to 50°C / min.

[0147] Shell formation process

[0148] In addition, a shell-forming process may be performed before the following washing and drying processes. The shell-forming process is the process of adding new fine resin particles and attaching them to the particles made in the aforementioned process to form a shell.

[0149] The added resin particles can have the same structure as the binder resin particles used as the core, or they can have a different structure.

[0150] Washing and drying process

[0151] The granules produced through the above process are washed and filtered with ion-exchanged water having a pH adjusted with sodium hydroxide or potassium hydroxide, and then washed and filtered multiple times with ion-exchanged water. Afterward, they are dried to obtain emulsified aggregated toner granules.

[0152] <Production Method of Toners>

[0153] The toner disclosed herein is a toner in which external additives are added to toner particles. Examples of external additive equipment include a double-cone mixer, a V-type mixer, a drum mixer, a super mixer, an FM mixer (manufactured by Nippon Coke & Engineering Co., Ltd.), a Nota mixer, and a Mechano Hybrid. To control the coating state of the external additives, the rotation speed, processing time, and jacket water temperature and volume in the aforementioned external additive equipment are adjusted to enable the preparation of the toner.

[0154] <Processing Box>

[0155] The processing cartridge disclosed herein has a photosensitive element as described above, a toner storage section for containing toner, and a developing unit for supplying toner to the surface of the photosensitive element, and can be configured as a main body that can be detachably mounted to an electrophotographic device.

[0156] Figure 1 An example of a schematic configuration of an electrophotographic apparatus having a processing box according to the present disclosure is shown.

[0157] The cylindrical (drum-shaped) photosensitive element 1 is driven to rotate around axis 2 at a predetermined circumferential speed (processing speed) in the direction of the arrow. During rotation, the surface of the photosensitive element 1 is charged to a predetermined positive or negative potential by means of the charging unit 3. Note that in... Figure 1The diagram illustrates a roller charging method using a roller-type charging member; however, charging methods such as corona charging, proximity charging, or injection charging can also be employed. The surface of the charged photosensitive member 1 is irradiated with exposure light 4 from an exposure unit (not shown) to form an electrostatic latent image corresponding to target image information. The exposure light 4 is light whose intensity is adjusted according to a time-series electro-digital image signal corresponding to the target image information, and is output from an image exposure unit such as slit exposure or laser beam scanning exposure. The electrostatic latent image formed on the surface of the photosensitive member 1 is developed (positive or reverse development) with toner contained in a developing unit 5 to form a toner image on the surface of the photosensitive member 1. The toner image formed on the surface of the photosensitive member 1 is transferred to a transfer material 7 by means of a transfer unit 6. At this time, a bias voltage opposite in polarity to the charge held by the toner is applied from a bias power supply (not shown) to the transfer unit 6. Furthermore, when the transfer material 7 is paper, the transfer material 7 is taken out from the paper feed section (not shown) and fed between the photosensitive member 1 and the transfer unit 6 in sync with the rotation of the photosensitive member 1. The transfer material 7, which transfers the toner image from the photosensitive member 1 to it, is separated from the surface of the photosensitive member 1, conveyed to the fixing unit 8, and undergoes fixing processing thereto produce an image (printed copy, photocopy) that is subsequently printed outside the electrophotographic device.

[0158] After the toner image is transferred onto the transfer material 7, the surface of the electrophotographic photosensitive component 1 is cleaned by removing adhering substances such as toner (transfer residue toner) using the cleaning unit 9. Using a cleaner-free system developed in recent years, the transfer residue toner can also be removed directly using a developer or similar device. Furthermore, the surface of the electrophotographic photosensitive component 1 is reused for image formation after undergoing a static removal process using pre-exposure light 10 from a pre-exposure unit (not shown). In the case where the charging unit 3 is a contact charging unit using a charging roller or similar device, a pre-exposure unit is not necessarily required. In this disclosure, multiple components of the aforementioned electrophotographic photosensitive component 1, charging unit 3, developing unit 5, and cleaning unit 9 are housed in a container and integrally supported to form a processing cartridge. This processing cartridge can be configured as a main body that can be detachably mounted to an electrophotographic device. For example, at least one of the group consisting of the charging unit 3, developing unit 5, and cleaning unit 9 is integrally supported with the electrophotographic photosensitive component 1 to form the cartridge. The box can be a processing box 11 that can be detachably mounted to the main body of an electrophotographic device, such as a guide unit 12. In the case that the electrophotographic device is a copier or printer, the exposure light 4 can be reflected or transmitted light from the original, or it can be light emitted by a scanning laser beam, driving an LED array, or driving a liquid crystal shutter array, etc., which reads the original with a sensor, converts it into a signal, and then follows that signal.

[0159] The following describes the methods for measuring the various properties of the photosensitive components and toners according to this disclosure.

[0160] <Calculation of the primary particle size of conductive particles>

[0161] First, the entire electrophotographic photosensitive element is immersed in methyl ethyl ketone (MEK) in a graduated cylinder and irradiated with ultrasound to peel off the resin layer, then the substrate of the electrophotographic photosensitive element is removed. Next, the insoluble portion (photosensitive layer and protective layer containing conductive particles) that is insoluble in MEK is filtered out and dried in a vacuum dryer. Furthermore, the obtained solid is then suspended in a 1:1 volume ratio mixture of tetrahydrofuran (THF) / methyl acetal, the insoluble portion is filtered out, and the filtrate is recovered and dried in a vacuum dryer. Conductive particles and protective layer resin are obtained through this operation. The filtrate is further heated to 500°C in an electric furnace to leave only the conductive particles as solids, and the conductive particles are recovered. The same treatment is applied to multiple electrophotographic photosensitive elements to ensure the required amount of conductive particles for measurement.

[0162] A portion of the recovered conductive particles was dispersed in isopropanol (IPA), and the dispersion was dropwise added onto a grid sieve (Cu 150J manufactured by JEOL Ltd.) with a supporting film. The conductive particles were then observed in STEM mode using a scanning transmission electron microscope (JEM2800 manufactured by JEOL Ltd.). Observations were performed at magnifications from 500,000× to 1,200,000× to facilitate the calculation of the particle size, and STEM images of 100 conductive particles were captured. In this case, the accelerating voltage was 200 kV, the probe size was 1 nm, and the image size was 1024×1024 pixels.

[0163] Using the obtained STEM image, the primary particle size was measured using the image processing software "Image-Pro Plus, manufactured by Media Cybernetics, Inc." First, using the Straight Line tool on the toolbar, select the scale bar displayed at the bottom of the STEM image. In this state, select "Set Scale" from the Analysis menu to open a new window and enter the pixel distance of the selected line in the Distance in Pixels field. Enter the scale value (e.g., 100) in the Known Distance field of the window, and then enter the scale unit (e.g., nm) in the Unit of Measurement field, and click "OK" to complete the scale setting. Next, using the Straight Line tool, draw a straight line with the maximum diameter of the conductive particles to calculate the particle size. Perform the same operation on 100 conductive particles, and use the average number of obtained values ​​(maximum diameter) as the primary particle size of the conductive particles.

[0164] <Calculation of Niobium / Titanium Atom Concentration Ratio>

[0165] A 5 mm square sample section was cut from the photosensitive element and then sliced ​​into 200 nm thick sections using an ultrasonic ultramicrotome (UC7 manufactured by Leica Microsystems GmbH) at a cutting speed of 0.6 mm / s. The sections were then observed using a scanning transmission electron microscope (JEM28 manufactured by JEOLLtd.) connected to an EDS analyzer (energy dispersive X-ray analyzer) at magnifications ranging from 500,000× to 1,200,000×.

[0166] Among the observed cross-sections of conductive particles, cross-sections of conductive particles with a maximum diameter of approximately 0.9 to 1.1 times the calculated primary particle diameter were visually selected. Subsequently, the spectra of the constituent elements in the selected cross-sections of conductive particles were acquired using an EDS analyzer to create EDS mapping images. Spectra were acquired and analyzed using an NSS (manufactured by Thermo Fischer Scientific, Inc.). As acquisition conditions, probe sizes of 1.0 nm or 1.5 nm were appropriately selected, with an accelerating voltage of 200 kV, a dead time of 15 to 30, a mapping resolution of 256 × 256, and a frame count of 300. EDS mapping images were acquired for 100 cross-sections of the conductive particles.

[0167] By analyzing the EDS mapping image obtained in this manner, the ratio of niobium atomic concentration (atomic %) to titanium atomic concentration (atomic %) within 5% of the maximum diameter of the particle measured from the particle surface is calculated. Specifically, the "Line Extraction" button on the NSS is first pressed to draw a straight line with the maximum diameter of the particle, and then information on the atomic concentration (atomic %) along the line drawn from one surface through the interior of the particle to the other surface is obtained. Particles with a maximum diameter less than 0.9 times or greater than 1.1 times the calculated primary particle diameter are excluded from further analysis. That is, only particles with a maximum diameter between 0.9 and 1.1 times the primary particle diameter are analyzed as follows. Next, the niobium atomic concentration (atomic %) within 5% of the maximum diameter of the particle measured from the particle surface is read on both sides of the particle surface, and the arithmetic mean of the two values ​​is calculated to obtain the "niobium atomic concentration (atomic %) within 5% of the maximum diameter of the particle measured from the particle surface". Similarly, the concentration of titanium atoms (atomic %) within 5% of the maximum diameter of the particle measured from the particle surface was obtained. These values ​​were then used to obtain the concentration ratio of niobium atoms to titanium atoms on both sides of the particle surface, within 5% of the maximum diameter of the particle measured from the particle surface, according to the following equation:

[0168] (The concentration ratio of niobium atoms to titanium atoms within 5% of the maximum diameter of the particle, measured from the particle surface) =

[0169] (Niobium atom concentration (atomic %) within 5% of the maximum diameter of the particle measured from the particle surface) / (Titanium atom concentration (atomic %) within 5% of the maximum diameter of the particle measured from the particle surface)

[0170] The smaller of the two obtained concentration ratios is used as the "concentration ratio of niobium atoms to titanium atoms within 5% of the maximum diameter of the particle measured from the particle surface" in this disclosure. Note that for typical particles, there is no significant difference between the two concentration ratios.

[0171] In addition, the niobium atom concentration (atomic %) and titanium atom concentration (atomic %) at the midpoint of the maximum diameter along the aforementioned line were recorded. Using these values, the "concentration ratio of niobium atoms to titanium atoms at the particle center" was obtained according to the following equation:

[0172] The concentration ratio of niobium atoms to titanium atoms in the center of the particle = (niobium atom concentration in the center of the particle (atomic %)) / (titanium atom concentration in the center of the particle (atomic %))

[0173] "The concentration ratio of niobium atom concentration to titanium atom concentration, defined relative to the concentration ratio of niobium atom concentration at the particle center, and defined as the concentration ratio of niobium atom concentration to titanium atom concentration within 5% of the maximum diameter of the particle measured from the particle surface," is calculated using the following equation:

[0174] (The ratio of niobium atom concentration to titanium atom concentration within 5% of the maximum diameter of the particle measured from the particle surface, relative to the niobium atom concentration / titanium atom concentration ratio determined at the particle center) =

[0175] (The ratio of niobium to titanium atoms within 5% of the maximum diameter of the particle, measured from the particle surface) / (The ratio of niobium to titanium atoms in the center of the particle).

[0176] <Calculation of the content of conductive particles>

[0177] Next, four 5mm square sample pieces were cut from the photosensitive element, and then the protective layer was three-dimensionally resized to 2μm×2μm×2μm using FIB-SEM Slice & View. The content of conductive particles in the total volume of the protective layer was calculated based on the contrast difference in the Slice & View. The Slice & View conditions were as follows:

[0178] Sample preparation for analysis: FIB method

[0179] Processing and observation equipment: NVision40 manufactured by SII NanoTechnology / Carl Zeiss NTS

[0180] Slice spacing: 10nm

[0181] Observation conditions:

[0182] Accelerating voltage: 1.0kV

[0183] Sample tilt angle: 54°

[0184] WD: 5mm

[0185] Detector: BSE detector

[0186] Aperture: 60μm, high current

[0187] ABC: Open

[0188] Image resolution: 1.25nm / pixel

[0189] Analysis was performed in a 2μm (vertical) × 2μm (horizontal) region, and the information from each section was integrated to obtain the data for each 8μm section. 3The volume V is (2μm length × 2μm width × 2μm thickness). Furthermore, the measurement environment is as follows: temperature: 23℃ and pressure: 1 × 10⁻⁶. -4 Pa. Alternatively, a processing and observation device such as the FEI Strata400S (sample tilt: 52°) manufactured by FEI Company can be used. Furthermore, information about each cross-section is obtained through image analysis of the area of ​​the specific conductive particles disclosed in this invention. Image analysis is performed using Image-Pro Plus image processing software manufactured by MediaCybernetics, Inc.

[0190] Based on the obtained information, the volume of each of the four sample pieces (2μm×2μm×2μm) was calculated (unit volume: 8μm). 3 The volume V of the conductive particles in this disclosure is used to calculate the content of conductive particles [volume %] (=Vμm). 3 / 8μm 3 ×100). The average content of conductive particles in each of the four sample pieces is determined as the content of conductive particles of this disclosure in the protective layer relative to the total volume of the protective layer [volume %].

[0191] In this case, for all four sample sheets, the film thickness t (cm) of the protective layer is measured by processing it to the boundary between the protective layer and the underlying layer, and the film thickness value of the protective layer is used to calculate the volume resistivity ρs in the following <Method for measuring the volume resistivity of the protective layer of the photosensitive component>.

[0192] Quantitative analysis of niobium atoms contained in conductive particles.

[0193] The number of niobium atoms contained in the conductive particles is quantified as follows.

[0194] The conductive particles recovered from the photosensitive element in the above-mentioned <Calculation of Primary Particle Size of Conductive Particles> were granulated to prepare samples using the following compression molding method. Using the prepared samples, measurements were performed using X-ray fluorescence spectrometry (XRF), and the niobium atom content of the entire conductive particle was quantified using the FP method.

[0195] Specifically, niobium pentoxide was quantified and the obtained quantitative value was converted into niobium atom content.

[0196] (i) Examples of devices used

[0197] X-ray fluorescence analyzer 3080 (manufactured by Rigaku Corporation)

[0198] (ii) Sample preparation

[0199] Samples were prepared using a sample pressing machine manufactured by MAEKAWA Testing Machine MFG Co.,LTD. 0.5g of conductive particles were added to an aluminum ring (model No. 3481E1), and the ring was pressed for 1 minute after a load of 5.0 tons was set, thus granulating the particles.

[0200] (iii) Measurement conditions

[0201] Measured diameter: 10φ

[0202] Measurement of potential and voltage: 50kV, 50 to 70mA

[0203] 2θ angle: 25.12°

[0204] Crystal plate: LiF

[0205] Measurement time: 60 seconds

[0206] <Powder X-ray Diffraction Measurement of Conductive Particles>

[0207] The following will show a method for determining whether the conductive particles used in the electrophotographic photosensitive component of this disclosure contain anatase titanium dioxide or rutile titanium dioxide.

[0208] Identification was performed using the Inorganic Materials Database (AtomWorks) of the National Institute for Materials Science (NIMS) based on patterns obtained from powder X-ray diffraction using CuKα X-rays. For the conductive particles contained in the protective layer of the electrophotographic photosensitive component of this disclosure, the aforementioned processing of <quantification of niobium atoms contained in conductive particles> was applied as an example.

[0209] Measuring equipment used: RINT-TTRII X-ray diffractometer manufactured by Rigaku Corporation; X-ray tube: Cu

[0210] Tube voltage: 50KV

[0211] Tube current: 300mA

[0212] Scanning method: 2θ / θ scan

[0213] Scanning speed: 4.0° / min

[0214] Sampling interval: 0.02°

[0215] Starting angle (2θ): 5.0°

[0216] Termination angle (2θ): 40.0°

[0217] Attachment: Standard sample rack

[0218] Filter: Not used

[0219] Incident monochromator: using

[0220] Counter monochromator: Not used

[0221] Diverging slit: Open

[0222] Longitudinal diverging slit: 10.00mm

[0223] Scattering slit: Open

[0224] Receiving slit: Open

[0225] Flat monochromator: using

[0226] Counter: Blink Counter

[0227] <Methods for measuring the volume resistivity of the protective layer>

[0228] The volume resistivity of this disclosure is measured using a pA (picoampere) meter.

[0229] First, it is manufactured by vapor deposition onto PET film. Figure 2 The diagram shows comb-shaped gold electrodes with an inter-electrode distance (D) of 180 μm and a length (L) of 59 mm, and a protective layer with a thickness (T1) of 2 μm is disposed thereon. Next, the DC current (I) when a DC voltage (V) of 100 V is applied between the comb-shaped electrodes is measured at temperatures of 23 °C / 50% RH and 32.5 °C / 80% RH, respectively, and the volume resistivity ρv (Ω·cm) is obtained by the following formula (1).

[0230] Volume resistivity ρv (Ω·cm)=V(V)×T1(cm)×L(cm) / {I(A)×D(cm)} (1)

[0231] In cases where it is difficult to identify the composition of conductive particles or binder resins in the protective layer, the surface resistivity is measured on the surface of the electrophotographic photosensitive element to convert it into volume resistivity. When measuring the volume resistivity of the protective layer coated on the surface of the photosensitive element, rather than the protective layer itself, it is desirable to measure the surface resistivity of the protective layer and then convert it into volume resistivity.

[0232] In this disclosure, gold is deposited onto the surface of a protective layer of an electrophotographic photosensitive component to create the coating. Figure 2The diagram shows a comb-shaped electrode with an inter-electrode distance (D) of 180 μm and a length (L) of 59 mm. Next, the direct current (I) when a DC voltage (V) of 1,000 V is applied between the comb-shaped electrodes is measured at 23 °C and 50% RH, and the surface resistivity ρ of the protective layer is determined by the ratio of DC voltage (V) to DC current (I). s .

[0233] Furthermore, the volume resistivity ρ is calculated using the thickness t (cm) of the protective layer measured in the above <Calculation of the content of conductive particles> by the following formula (2). v (Ω·cm).

[0234] ρ v =ρ s ×t (2)

[0235] (ρ v Volume resistivity, ρ s : Surface resistivity, t: thickness of protective layer)

[0236] Since this measurement involves measuring a minute current, a device capable of measuring minute currents is preferred as a resistance measuring instrument. A real-world example is the Picoammeter 4140B manufactured by Hewlett-Packard Company. The appropriate signal-to-noise ratio can be obtained by selecting the comb electrode to be used and the applied voltage based on the material and resistance value of the charge injection layer.

[0237] <Measurement of the content of polyvalent metal elements in toner particles (ICP-AES)>

[0238] (1) A method for obtaining toner particles by washing away external additive particles from the toner.

[0239] When the toner contains external additives such as silica microparticles, the following process is used to remove the external additives from the surface of the toner particles.

[0240] 5g of toner was weighed into a 200ml polystyrene cup with a lid using a precision balance. 100ml of methanol was added, and the mixture was dispersed using an ultrasonic disperser for 5 minutes. After confirming that the toner had fully precipitated by centrifugation, the supernatant was discarded. The process of dispersing the mixture with methanol and discarding the supernatant was repeated three times. Then, 100ml of 10% NaOH and a few drops of "Contaminon N" (a 10% by mass aqueous solution of a pH 7 neutral detergent for precision instrument cleaning, composed of nonionic surfactants, anionic surfactants, and organic detergent builders, manufactured by Wako Pure Chemical Industries, Ltd.) were added, gently mixed, and allowed to stand for 24 hours. Afterward, the mixture was separated using a centrifuge. At this point, the toner particles were repeatedly rinsed with distilled water to remove any NaOH residue. The recovered toner particles were thoroughly dried in a vacuum dryer to obtain the toner granules. The above operation dissolved and removed the external additives of silica particles.

[0241] (2) Measurement of the content of polyvalent metal elements in toner particles

[0242] The content of polyvalent metal elements in toner particles was quantified using an inductively coupled plasma atomic emission spectrometer (ICP-AES manufactured by Seiko Instruments Inc.).

[0243] As a pretreatment, 8.00 ml of 60% nitric acid (for atomic absorption analysis, manufactured by Kanto Chemical Co., Inc.) was mixed with 100.0 mg of toner particles to decompose them into acids.

[0244] During acid decomposition, toner particles were treated for 1 hour in a sealed container at an internal temperature of 220°C using an ETHOS1600 microwave high-power sample pretreatment device (Milestone General KK) to prepare a solution sample containing polyvalent metal elements.

[0245] Subsequently, ultrapure water was added to bring the total sample volume to 50.00 g, which was then used as the measurement sample. Calibration curves were constructed for each multivalent metal element, and the metal content in each sample was quantitatively determined. Note that the solution was prepared such that ultrapure water was added to 8.00 ml of nitric acid to bring the total volume to 50.00 g and used as a blank sample for measurement. The metal content in the blank sample was subtracted.

[0246] <Identification of Wax in Toners>

[0247] (1) Method for separating wax from toner

[0248] The wax in the toner can be measured without removing the toner; however, it is preferable to separate the toner.

[0249] First, the melting point of the wax in the toner was determined using a thermal analyzer (DSC Q2000 manufactured by TA Instruments Japan Inc.). Approximately 3.0 mg of toner sample was placed in a sample container on an aluminum tray (KIT NO. 0219-0041), which was then placed on a support unit and placed in an electric furnace. Under a nitrogen atmosphere, the sample was heated from 30°C to 200°C at a heating rate of 10°C / min, and the DSC curve was measured using a differential scanning calorimeter (DSC) to determine the melting point of the wax in the toner sample.

[0250] Next, the toner is dispersed in ethanol, a poor solvent for the toner, and the temperature is raised to above the melting point of the wax. Pressure may be applied if necessary. This process melts the wax, which has undergone a temperature rise above its melting point, and extracts it into the ethanol. With further heating and pressure on the wax, the wax can be separated from the toner by solid-liquid separation under maintained pressure. The extract is then dried and cured to obtain the wax.

[0251] (2) Identification of waxes by pyrolysis GCMS

[0252] The following shows the specific conditions for identifying waxes by pyrolysis GCMS.

[0253] Mass spectrometer: ISQ manufactured by Thermo Fischer Scientific, Inc.

[0254] GC System: Focus GC manufactured by Thermo Fischer Scientific, Inc.

[0255] Ion source temperature: 250℃

[0256] Ionization method: EI

[0257] Mass range: 50 to 1000 m / z

[0258] Column: HP-5MS [30m]

[0259] Pyrolysis unit: JPS-700 manufactured by Japan Analytical Industry Co., Ltd.

[0260] A small amount of wax, separated by an extraction process, was added to a pyro-foil at 590°C, along with 1 μL of tetramethylammonium hydroxide (TMAH). Pyrolytic GC-MS measurements of the prepared sample were performed under these conditions to obtain peaks derived from the wax. In the case of ester compounds, peaks were obtained for both alcohol and carboxylic acid components. The alcohol and carboxylic acid components were detected as their methylates using TMAH as a methylating agent. Analysis of the obtained peaks and identification of the ester compound's structure also allowed for the determination of molecular weight.

[0261] <Method for measuring the weight-average particle size (D4) of toners>

[0262] The weight-average particle size (D4) of the toner is calculated below.

[0263] The following measuring device was used: a Coulter Counter Multisizer, a precision particle size distribution measuring device equipped with a 100μm orifice tube and utilizing the pore resistance method. ", manufactured by Beckman Coulter, Inc.

[0264] For setting measurement conditions and analyzing measurement data, use the included dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.). Note that measurements are performed using 25,000 valid measurement channels.

[0265] Use an electrolyte solution for measurement, such as "ISOTON II" (manufactured by Beckman Coulter, Inc.), to dissolve premium sodium chloride in ion-exchanged water to achieve a solution concentration of 1.0%.

[0266] Before performing measurements and analysis, the dedicated software will be set up as follows.

[0267] In the "Change Standard Measurement Method (SOMME)" interface of the dedicated software, set the total count in the control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained by using "Standard Particle 10.0 μm" (manufactured by Beckman Coulter, Inc.). The threshold and noise level are automatically set by pressing the "Measurement Threshold / Noise Level" button. Additionally, set the current to 1,600 μA, the gain to 2, and the electrolyte to ISOTON II, and check "Flush the port after measurement".

[0268] In the "Pulse to Particle Size Conversion Setting" interface of the dedicated software, set the element spacing to logarithmic particle size, set the particle size element to 256 particle size elements, and set the particle size range to 2μm to 60μm.

[0269] The specific measurement method is as follows.

[0270] (1) Fill a 250mL round-bottom glass beaker for Multisizer 3 with 200.0mL of electrolyte solution, place it on the sample stage, and stir the beaker counterclockwise at 24 rpm. Then, use the "rinse tube" function of the dedicated software to remove dirt and air bubbles from the tube.

[0271] (2) Place 30.0 mL of electrolyte aqueous solution in a 100 mL flat-bottomed glass beaker. Add 0.3 mL of a 10% by mass aqueous solution of "Contaminon N" (a neutral detergent for cleaning precision measuring instruments with a pH of 7, consisting of nonionic surfactants, anionic surfactants and organic detergent builders, manufactured by Wako Pure Chemical Industries, Ltd.) diluted three times with deionized water.

[0272] (3) Prepare an ultrasonic disperser, "Tetra 150 Ultrasonic Dispersion System" (manufactured by Nikkaki Bios Co., Ltd.), with two 50kHz oscillators built-in and a power output of 120W, with a phase offset of 180 degrees. Add 3.3L of ion-exchanged water and 2.0mL of Contaminon N to the water tank of the ultrasonic disperser.

[0273] (4) Place the beaker from (2) above into the beaker fixing hole of the ultrasonic disperser and start the ultrasonic disperser. Then, adjust the height of the beaker to maximize the resonance state of the electrolyte aqueous solution surface in the beaker.

[0274] (5) While irradiating the electrolyte aqueous solution in the beaker described in (4) with ultrasound, gradually add 10 mg of colorant or the like to the electrolyte aqueous solution and disperse the mixture. Then, continue the ultrasonic dispersion treatment for another 60 seconds. During ultrasonic dispersion, adjust the water temperature in the water tank appropriately to be above 10°C and below 40°C.

[0275] (6) The electrolyte solution of (5) above, in which the colorant or the like is dispersed, is added dropwise to the round-bottom beaker of (1) above, which is set in the sample stage, by using a pipette to adjust the measurement concentration to 5%. Then, the measurement is performed until the number of particles reaches 50,000.

[0276] (7) Analyze the measurement data using the dedicated software provided with the equipment and calculate the weight-average particle size (D4). When the dedicated software is set to Figure / Volume %, the "Average Diameter" on the "Analysis / Volume Statistics (Arithmetic Mean)" interface is the weight-average particle size (D4).

[0277] Example

[0278] The photosensitive element and toner of this disclosure will be described in detail below using examples and comparative examples. Note that in the following examples, unless otherwise stated, "parts" refers to parts by weight.

[0279] The following describes a production example of a photosensitive component.

[0280] <Examples 1 to 3 of titanium dioxide particle production>

[0281] The titanium oxide particles disclosed herein preferably have anatase content of 90% to 100%, and titanium oxide particles with anatase content of about 100% can be produced by the following method.

[0282] Here, the anatase mineralization is determined by measuring the ratio of the intensity IA of the strongest interference line (surface index 101) of anatase to the intensity IR of the strongest interference line (surface index 101) of rutile in powder X-ray diffraction of titanium oxide particles, and then substituting these obtained values ​​into the following formula.

[0283] Anatase mineralization (%) = 100 / (1 + 1.265 × IR / IA)

[0284] In this disclosure, a solution containing titanium oxysulfate is heated and hydrolyzed to prepare an aqueous titanium dioxide slurry, which is then dehydrated and calcined to obtain anatase titanium dioxide particles. By controlling the concentration of the titanium oxysulfate solution, the number-average particle size of the anatase titanium dioxide particles is controlled to obtain titanium dioxide particles 1 with a number-average particle size of 150 nm, titanium dioxide particles 2 with a number-average particle size of 160 nm, and titanium dioxide particles 3 with a number-average particle size of 130 nm.

[0285] <Production example of titanium dioxide particles containing niobium atoms 1>

[0286] 100 g of titanium oxide particles 1 were dispersed in water to form a 1 L aqueous suspension, which was then heated to 60 °C. To this solution, a titanium niobate solution (containing 3 g of niobium pentachloride (NbCl5) dissolved in 100 mL of 11.4 mol / L hydrochloric acid and 33.7 g of titanium in 600 mL of titanium sulfate solution, in which the niobium to titanium mass ratio was 1.0 / 33.7) was added dropwise over 3 hours in parallel to adjust the pH of the suspension to 2-3. After the addition was complete, the suspension was filtered, washed, and dried at 110 °C for 8 hours. The dried product was then heated at 800 °C for 1 hour in an atmospheric atmosphere (calcination) to obtain titanium oxide particles 1 containing niobium atoms with a non-uniform distribution of niobium atoms near the surface. Table 1 shows the physical properties of the niobium-containing titanium oxide particles 1.

[0287] <Production example of titanium dioxide particles containing niobium atoms 2>

[0288] Except for changing titanium oxide particles 1 to titanium oxide particles 2 and appropriately changing the coating conditions, niobium-containing titanium oxide particles 2 were obtained in the same manner as in the production of niobium-containing titanium oxide particles 1. Table 1 shows the physical properties of niobium-containing titanium oxide particles 2.

[0289] <Production example of titanium dioxide particles containing niobium atoms 3>

[0290] Niobium sulfate (a water-soluble niobium compound) is added to an aqueous titanium dioxide slurry obtained by hydrolyzing an aqueous solution of titanium oxysulfate. Niobium sulfate is added at a ratio of 0.2% by mass (based on niobium ions) relative to the amount of titanium in the slurry (calculated as titanium dioxide).

[0291] Following the hydrolysis and dehydration described above, the slurry was calcined at a temperature of 1,000 °C. As a result, anatase titanium oxide particles containing 0.20% by mass of niobium atoms and a number-average particle size of 150 nm were obtained (niobium-containing titanium oxide particles before coating).

[0292] Except for changing titanium oxide particles 1 to the aforementioned niobium-containing titanium oxide particles and appropriately changing the coating conditions, niobium-containing titanium oxide particles 3 were obtained in the same manner as in the production of niobium-containing titanium oxide particles 1. The obtained niobium-containing titanium oxide particles 3 are particles in which niobium atoms are also present inside the particles. Table 1 shows the physical properties of the niobium-containing titanium oxide particles 3.

[0293] <Production examples of titanium dioxide particles containing niobium atoms, 4 to 9>

[0294] Except for altering the number-average particle size of the niobium-containing titanium oxide particles before coating by changing the aqueous solution of niobium oxysulfate and appropriately changing the coating conditions, each of the niobium-containing titanium oxide particles 4 to 9 was obtained in the same manner as in the production of niobium-containing titanium oxide particles 3. Table 1 shows the physical properties of the niobium-containing titanium oxide particles 4 to 9.

[0295] <Production example of titanium dioxide particles 10 containing niobium atoms>

[0296] Except for changing the amount of niobium ions and not using a niobium solution containing 3g of niobium pentachloride (NbCl5) dissolved in 100mL of 11.4mol / L hydrochloric acid, niobium-containing titanium oxide particles 10 were obtained in the same manner as in the production of niobium-containing titanium oxide particles 3. Table 1 shows the physical properties of the niobium-containing titanium oxide particles 10.

[0297] <Titanium oxide particles containing niobium atoms 11>

[0298] Except for changing the concentration of the titanium oxysulfate aqueous solution and the amount of niobium ions and without applying a coating, niobium-containing titanium oxide particles 11 were obtained in the same manner as in the production of niobium-containing titanium oxide particles 3. Table 1 shows the physical properties of the niobium-containing titanium oxide particles 11.

[0299] [Table 1]

[0300]

[0301] <Production Example of Conductive Particle 1>

[0302] Prepare the following materials.

[0303] • 100.0 parts of titanium dioxide particles containing niobium atoms (specific gravity: 4 g / cm³) 3 )

[0304] • 3.0 parts of the compound shown in formula (S-1) as a silane coupling agent (product name: KBM-3033, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0305]

[0306] They were mixed with 200.0 parts toluene, and the mixture was stirred for 4 hours, filtered, washed, and then further heated at 130°C for 3 hours. Surface treatment was performed in this manner to obtain conductive particles 1. The physical properties of conductive particles 1 are shown in Table 2. Note that the niobium atom content in Table 2 refers to the niobium atom content in the conductive particles and is a value determined by elemental analysis using X-ray fluorescence (XRF).

[0307] [Table 2]

[0308] Particles Surface treatment agent A / B Niobium atomic content (mass%) Conductive particles 1 Titanium oxide particles containing niobium atoms 1 Equation (S-1) 7.9 5.0 Conductive particles 2 Titanium oxide particles containing niobium atoms 2 Equation (S-1) 7.9 5.0 Conductive particles 3 Titanium oxide particles containing niobium atoms 3 Equation (S-1) 15.8 10.0 Conductive particles 4 10 titanium oxide particles containing niobium atoms Equation (S-1) 0 5.0 Conductive particles 5 Titanium oxide particles containing niobium atoms 11 Equation (S-1) 1 0.5 Conductive particles 6 Titanium oxide particles 3 Equation (S-1) - - Conductive particles 7 Tin oxide particles Equation (S-2) - - Conductive particles 8 Titanium oxide particles containing niobium atoms 4 Equation (S-1) 0.04 8.0 Conductive particles 9 Titanium oxide particles containing niobium atoms 5 Equation (S-1) 4.1 2.6 Conductive particles 10 Titanium oxide particles containing niobium atoms 6 Equation (S-1) 7.9 5.0 Conductive particles 11 Titanium oxide particles containing niobium atoms 7 Equation (S-1) 7.9 5.0 Conductive particles 12 Titanium oxide particles containing niobium atoms 8 Equation (S-1) 0.8 0.5 Conductive particles 13 Titanium oxide particles containing niobium atoms 9 Equation (S-1) 23.7 15

[0309] In the table, A represents the "concentration ratio of niobium atoms to titanium atoms within 5% of the maximum diameter of the particle measured from the particle surface", and B represents the "concentration ratio of niobium atoms to titanium atoms in the center of the particle".

[0310] <Production examples of conductive particles 2 to 6 and 8 to 13>

[0311] Except for changing the niobium-containing titanium oxide particles to be used as shown in Table 2 and appropriately altering the surface treatment conditions, each of conductive particles 2 to 6 and 8 to 13 is obtained in the same manner as in the production of conductive particles 1. The physical properties of conductive particles 2 to 6 and 8 to 13 are shown in Table 2.

[0312] <Production Example of Conductive Particle 7>

[0313] Prepare the following materials.

[0314] • 100.0 parts of tin oxide particles (product name: S-2000, manufactured by Mitsubishi Materials Corporation, number average particle size of 100nm)

[0315] • 20.0 parts of the compound shown in formula (S-2)

[0316]

[0317] They were mixed with 200.0 parts of toluene, and the mixture was stirred with a stirrer for 4 hours, filtered, washed, and then further heated at 130°C for 3 hours. Conductive particles 7 were obtained in this manner. The physical properties of conductive particles 7 are shown in Table 2.

[0318] <Production Example of Electrophotographic Photosensitive Component 1>

[0319] An aluminum cylinder (JIS-A3003, aluminum alloy) with a diameter of 24 mm and a length of 257.5 mm is used as the support (conductive support).

[0320] (Example of conductive layer manufacturing)

[0321] Next, prepare the following materials.

[0322] • 214.0 parts of titanium oxide (TiO2) particles coated with oxygen-deficient tin oxide (SnO2) as metal oxide particles (number average particle size of 230 nm)

[0323] • 132.0 parts of phenolic resin (monomer / oligomer of phenolic resin) as a binder (product name: PRIOPHEN J-325, manufactured by DIC Corporation; resin solids content: 60% by mass)

[0324] 98.0 parts of 1-methoxy-2-propanol as solvent

[0325] They were placed in a sand mill using 450.0 parts of glass beads with a diameter of 0.8 mm and dispersed under the following conditions to obtain a dispersion: speed: 2,000 rpm, dispersion time: 4.5 hours, and cooling water set temperature: 18°C. The glass beads were removed from the dispersion using a sieve (aperture: 150 μm).

[0326] Silicone resin particles (product name: TOSPEARL 120, manufactured by Momentive Performance Materials Inc., with an average particle size of 2 μm) were added to the obtained dispersion as a surface roughening agent. The amount of silicone resin particles added was 10% by mass relative to the total mass of metal oxide particles and binder material in the dispersion after the glass beads were removed. In addition, silicone oil (product name: SH28PA, manufactured by Dow Toray Co., Ltd.) as a leveling agent was added to the dispersion to make it 0.01% by mass relative to the total mass of metal oxide particles and binder material in the dispersion.

[0327] Next, a mixed solvent of methanol and 1-methoxy-2-propanol (mass ratio 1:1) is added to the dispersion so that the total mass (i.e., the mass of solids) of the metal oxide particles, binder, and surface roughening agent in the dispersion is 67% by mass relative to the mass of the dispersion. Afterward, the mixture is stirred and a coating solution for preparing the conductive layer is prepared.

[0328] The support is coated with the conductive layer coating liquid by immersing it in the conductive layer coating liquid, and the coated support is heated at 140°C for 1 hour to form a conductive layer with a thickness of 30 μm.

[0329] (Example of primer coating production)

[0330] Next, prepare the following materials.

[0331] ·3.1 parts of electron transport material represented by the following formula (E-1)

[0332] • 6.5 parts of capped isocyanate (product name: DURANATE SBB-70P, manufactured by Asahi Kasei Chemicals Corporation)

[0333] • 0.40 parts styrene-acrylic resin (product name: UC-3920, manufactured by Toagosei Co., Ltd.)

[0334] • 1.8 parts silica slurry (product name: IPA-ST-UP, manufactured by Nissan Chemical Corporation, solids concentration: 15% by mass, viscosity: 9 mPa·s)

[0335] They were dissolved in a mixed solvent of 48.0 parts 1-butanol and 24.0 parts acetone to prepare a coating solution for the primer layer.

[0336] The conductive layer is coated with the primer coating liquid by immersing the conductive layer in the primer coating liquid, and the coating is heated at 170°C for 30 minutes to form a primer coating with a thickness of 0.7 μm.

[0337]

[0338] (Example of photosensitive layer production)

[0339] Next, prepare 10.0 parts of hydroxy gallium phthalocyanine in crystalline form with peaks at 7.5° and 28.4° in the pattern obtained from CuKα characteristic X-ray diffraction and 5 parts of polyvinyl butyral resin (product name: S-LEC BX-1, manufactured by SEKISUICHEMICAL CO.,LTD.).

[0340] They were added to 200.0 parts of cyclohexanone, and the mixture was dispersed in a sand mill with glass beads of 0.9 mm in diameter for 6 hours. 150.0 parts of cyclohexanone and 350.0 parts of ethyl acetate were further added to the mixture, and it was diluted with the cyclohexanone and ethyl acetate to obtain a diluted coating solution for the charge-generating layer.

[0341] The base coat was coated with the obtained coating liquid by immersing the base coat in the solution, and the coating was dried at 95°C for 10 minutes to form a charge generation layer with a thickness of 0.20 μm.

[0342] X-ray diffraction measurements were performed under the following conditions.

[0343] [Powder X-ray Diffraction Measurement]

[0344] Measurement equipment used: RINT-TTRII X-ray diffractometer, manufactured by Rigaku Corporation.

[0345] X-ray tube: Cu

[0346] Tube voltage: 50KV

[0347] Tube current: 300mA

[0348] Scanning method: 2θ / θ scan

[0349] Scanning speed: 4.0° / min

[0350] Sampling interval: 0.02°

[0351] Starting angle (2θ): 5.0°

[0352] Termination angle (2θ): 40.0°

[0353] Attachment: Standard sample rack

[0354] Filter: Not used

[0355] Incident monochromator: using

[0356] Counter monochromator: Not used

[0357] Diverging slit: Open

[0358] Longitudinal diverging slit: 10.00mm

[0359] Scattering slit: Open

[0360] Receiving slit: Open

[0361] Flat monochromator: using

[0362] Counter: Blink Counter

[0363] Next, prepare the following materials.

[0364] • 6.0 parts of charge-transporting material (hole-transporting material) represented by the following formula (C-1)

[0365] • 3.0 parts of charge-transporting material (hole-transporting material) represented by the following formula (C-2)

[0366] • 1.0 part of charge-transporting material (hole-transporting material) represented by the following formula (C-3)

[0367] • 10.0 parts polycarbonate (product name: Iupilon Z400, manufactured by Mitsubishi Engineering-Plastics Corporation)

[0368] • 0.02 parts of polycarbonate resin having copolymer units of the following formulas (C-4) and (C-5) (x / y = 0.95 / 0.05: viscosity-average molecular weight = 20,000)

[0369] A coating solution for the charge transport layer was prepared by dissolving the components in a mixed solvent of 25.0 parts o-xylene, 25.0 parts methyl benzoate, and 25.0 parts dimethoxymethane. The charge generation layer was coated with the prepared coating solution by immersing it in the solution, and the coating was dried at 120°C for 30 minutes to form a charge transport layer with a thickness of 12 μm.

[0370]

[0371]

[0372] (Example of surface protective layer production)

[0373] Next, prepare the following materials.

[0374] • 1.0 part of a compound represented by the following structural formula (O-1) as an adhesive resin

[0375]

[0376] • 4.0 parts of conductive particles as conductive particles 1

[0377] They were mixed in a mixed solvent of 5.0 parts 1-propanol and 5.0 parts cyclohexane and stirred for 6 hours. This method was used to prepare the coating solution for the protective layer.

[0378] The charge transport layer was coated with a protective coating solution to form a film by immersing the protective layer in a solution, and the resulting film was dried at 50°C for 6 minutes. Then, under a nitrogen atmosphere, the film was irradiated with an electron beam for 1.6 seconds while the support (the irradiated object) was rotated at 300 rpm under the following conditions: accelerating voltage of 70 kV and beam current of 5.0 mA. The dose at the protective layer location was 15 kGy.

[0379] Subsequently, the coating was heated to 117°C under a nitrogen atmosphere. The oxygen concentration from electron beam irradiation to the subsequent heat treatment was 10 ppm.

[0380] Next, allow the coating to cool naturally in air until it reaches a temperature of 25°C, and then heat-treat the coating at a temperature of 120°C for 1 hour to form a surface protective layer with a film thickness of 2μm.

[0381] Electrophotographic photosensitive element 1 is produced in this manner. The physical properties of electrophotographic photosensitive element 1 are shown in Table 3.

[0382] [Table 3]

[0383]

[0384] <Production Examples of Electrophotographic Photosensitive Components 2 to 6, 8 to 13, 15 and 16>

[0385] Except for the changes in the type and content (volume %) of conductive particles used in the production example of the surface protective layer as shown in Table 3, each of the electrophotographic photosensitive components 2 to 6, 8 to 13, 15 and 16 is produced in the same manner as in the production example of the electrophotographic photosensitive component 1. The physical properties of the electrophotographic photosensitive components 2 to 6, 8 to 13, 15 and 16 are shown in Table 3.

[0386] <Production Example of Electrophotographic Photosensitive Component 7>

[0387] Except for the following changes (in the production example of the surface protective layer), the electrophotographic photosensitive component 7 is obtained in the same manner as in the production example of the electrophotographic photosensitive component 1.

[0388] The following is a coating liquid for preparing a surface protective layer.

[0389] First, prepare the following materials.

[0390] · 16.0 parts conductive particles 5

[0391] • 10.0 parts of the compound represented by the following formula (H-7)

[0392] • 1.0 part of polymerization initiator (1-hydroxycyclohexyl)(phenyl) methyl ketone.

[0393] Mix them with 40 parts n-propanol and disperse the mixture in a sand mill for 2 hours to prepare a coating solution for the protective layer.

[0394] Except for using the coating liquid for the protective layer, the electrophotographic photosensitive element 7 is manufactured in the same manner as the electrophotographic photosensitive element 1. The physical properties of the electrophotographic photosensitive element 7 are shown in Table 3.

[0395]

[0396] <Production Example of Electrophotographic Photosensitive Component 14>

[0397] Except that the amount of conductive particles 5 added in the (surface protective layer production example) is changed to 10.0 parts by mass, the electrophotographic photosensitive component 14 is obtained in the same manner as in the production example of the electrophotographic photosensitive component 7. The physical properties of the electrophotographic photosensitive component 14 are shown in Table 3.

[0398] <Production Example of Electrophotographic Photosensitive Component 17>

[0399] Except for the following changes (production example of surface protective layer), the electrophotographic photosensitive element 17 is obtained in the same manner as in the production example of electrophotographic photosensitive element 1.

[0400] The following is a coating liquid for preparing a surface protective layer.

[0401] First, prepare the following materials.

[0402] • 10.0 parts of free radical polymerizable monomer (product name: TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd.)

[0403] • 5 parts of the compound represented by the following formula (H-1)

[0404] • 0.15 parts of the compound represented by the following formula (H-2)

[0405] • 0.15 parts of the compound represented by the following formula (H-3)

[0406] • 1.5 parts fluoropolymer granules (product name: MPE-056, manufactured by DuPont-Mitsui Fluorochemicals Co., Ltd.)

[0407] • 0.75 parts photoinitiator (product name: Irgacure 184, manufactured by BASF Japan Ltd.)

[0408]

[0409] Mix them into 100.0 parts of tetrahydrofuran and stir with a stirrer for 6 hours to prepare a coating solution for the protective layer.

[0410] The protective layer was coated with a coating liquid using a spraying method in a nitrogen gas flow to form a coating film, which was then placed in a nitrogen gas flow for 10 minutes and dried. Subsequently, UV irradiation was carried out in a UV light irradiation booth with an oxygen concentration of less than 2% inside a nitrogen-purged chamber under the following conditions.

[0411] Metal halide lamp: 160W / cm

[0412] Irradiation distance: 120mm

[0413] Irradiation intensity: 700mW / cm 2

[0414] Irradiation time: 60 seconds

[0415] In addition, the coating was dried at 130°C for 20 minutes to form a surface protective layer with a film thickness of 5 μm.

[0416] Electrophotographic photosensitive element 17 is obtained in this manner. The physical properties of electrophotographic photosensitive element 17 are shown in Table 3.

[0417] The following describes a production example of toner.

[0418] <Example of preparation of binder resin particle dispersion>

[0419] 78.0 parts styrene, 20.7 parts butyl acrylate, 1.3 parts acrylic acid as a carboxyl-contributing monomer, and 3.2 parts lauryl mercaptan were mixed and dissolved. 1.5 parts of an aqueous solution of NEOGEN RK (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) in 150.0 parts of ion-exchanged water were added to this solution, and the mixture was dispersed.

[0420] While slowly stirring for another 10 minutes, add 0.3 parts of an aqueous solution of potassium persulfate in 10.0 parts of ion-exchanged water. After nitrogen purging, carry out emulsion polymerization at 70°C for 6 hours. After polymerization is complete, cool the reaction solution to room temperature and add ion-exchanged water to obtain a resin particle dispersion 1 with a solids concentration of 12.5% ​​by mass and a median particle size of 0.2 μm by volume.

[0421] The obtained resin particles were partially washed with pure water to remove the surfactant and dried under reduced pressure to measure the acid value. The acid value of the resin was measured and confirmed to be 9.5 mg KOH / g.

[0422] <Example of preparation of release agent dispersion 1>

[0423] 100.0 parts of behenate (melting point: 72.1℃) and 15.0 parts of NEOGEN RK were mixed with 385.0 parts of deionized water, and the mixture was dispersed for about 1 hour using a JN100 wet sandblasting machine (manufactured by Tsunemitsu Co., Ltd.) to obtain release agent dispersion 1. The wax concentration of release agent dispersion 1 was 20.0% by mass.

[0424] <Example of preparation of release agent dispersion 2>

[0425] 100.0 parts of pentaerythritol tetrabenzyl ester (melting point: 84.2℃) and 15 parts of NEOGEN RK were mixed in 385.0 parts of ion-exchanged water, and the mixture was dispersed for about 1 hour using a wet sandblasting machine JN100 (manufactured by Tsunemitsu Co., Ltd.) to obtain release agent dispersion 2. The wax concentration of release agent dispersion 2 was 20.0% by mass.

[0426] <Example of preparation of release agent dispersion 3>

[0427] 100.0 parts of hydrocarbon wax HNP-9 (manufactured by Nippon Seiro Co., Ltd., melting point: 75.5°C) and 15.0 parts of NEOGEN RK were mixed in 385.0 parts of ion-exchanged water, and the mixture was dispersed for about 1 hour using a wet polishing mill JN100 (manufactured by Tsunemitsu Co., Ltd.) to obtain release agent dispersion 3. The wax concentration of release agent dispersion 3 was 20.0% by mass.

[0428] <Example of colorant dispersion preparation>

[0429] 100.0 parts of carbon black "Nipex 35 (manufactured by Orion Engineered Carbons SA)" as a colorant and 15 parts of NEOGEN RK were mixed in 885.0 parts of ion-exchanged water, and the mixture was dispersed for about 1 hour using a wet shot mill JN100 to obtain a colorant dispersion.

[0430] <Production Example of Silica Particles 1>

[0431] Untreated dry silica with a primary particle size of 18 nm was added to a reactor equipped with a stirrer and heated to 200 °C in a fluidized state with the aid of stirring.

[0432] The reactor was purged with nitrogen to seal it, and 25.0% by weight of dimethyl silicone oil (viscosity = 100 mm) was added. 2 100.0% by mass of dry silica was sprayed at a rate of ( / second) and stirred for 30 minutes. Subsequently, the sprayed silica was heated to 300°C while stirring, and after stirring for another 2 hours, it was removed and pulverized to obtain silica particles 1. Note that silica particles 1 have a hydrophobicity of 94.0%.

[0433] <Production Example of Toner 1>

[0434] 265.0 parts of resin particle dispersion, 10.0 parts of release agent dispersion 1, and 10.0 parts of colorant dispersion were dispersed using a homogenizer (ULTRA-TURRX T50 manufactured by IKA Japan KK). While stirring, the temperature in the container was adjusted to 30°C, and 1 mol / L sodium hydroxide solution was added to adjust the pH to 8.0.

[0435] An aqueous solution of 0.25 parts aluminum chloride dissolved in 10.0 parts ion-exchanged water was added as an agglomerating agent at 30°C and under stirring for 10 minutes. After allowing the solution to stand for 3 minutes, the mixture was heated to 50°C to produce aggregated particles. Under these conditions, the particle size of the aggregated particles was determined using a "Coulter CounterMultisizer" manufactured by Beckman Coulter, Inc. "To measure. When the weight-average particle size reaches 6.0 μm, add 0.90 parts sodium chloride and 5.0 parts NEOGEN RK to stop particle growth."

[0436] Add 1 mol / L sodium hydroxide aqueous solution to adjust the pH to 9.0, then heat the mixture to 95°C to spherify the aggregated particles. When the average sphericity reaches 0.980, begin cooling them and allow them to cool to room temperature to obtain toner particle dispersion 1.

[0437] Hydrochloric acid was added to the obtained toner particle dispersion 1 to adjust the pH to below 1.5, and the mixture was stirred for 1 hour, allowed to stand, and then subjected to solid-liquid separation using a filter press to obtain a toner filter cake. This was re-slurryed with deionized water to prepare a new dispersion, which was then subjected to solid-liquid separation using the same filter. Re-slurrying and solid-liquid separation were repeated until the conductivity of the filtrate reached below 5.0 μS / cm, and the secondary slurry was finally subjected to solid-liquid separation to obtain the toner filter cake. The obtained toner filter cake was dried and further classified using a classifier to achieve a weight-average particle size (D4) of 6.0 μm, thereby obtaining toner particles 1.

[0438] 1.0 part of silica particles 1 was externally mixed with 100.0 parts of the toner particles 1 obtained above using an FM10C (manufactured by Nippon Coke & Engineering Co., Ltd.). External addition was performed under the following conditions: using an A0 blade as the lower blade, setting the distance from the deflector wall to 20 mm, supplying 2.0 kg of toner particles, and rotating at a speed of 66.6 s. -1 The external addition time is 10 minutes, the cooling water temperature is 20℃, and the flow rate is 10L / min.

[0439] The particles obtained above were then sieved through a sieve with an opening of 200 μm to obtain toner 1. Table 4 shows the physical properties of the obtained toner 1.

[0440] [Table 4]

[0441]

[0442] <Production Example of Toner 2>

[0443] Except for the use of release agent dispersion 2, toner 2 was obtained in the same manner as in the production example of toner 1. Table 4 shows the physical properties of the obtained toner 2.

[0444] <Production Example of Toner 3>

[0445] Except for the use of release agent dispersion 3, toner 3 was obtained in the same manner as in the production example of toner 1. Table 4 shows the physical properties of the obtained toner 3.

[0446] <Production examples of colorants 4 to 6 and 15>

[0447] Except for changing the amount of aluminum chloride added as an agglomerating agent as described in Table 4, each of toners 4 to 6 and 15 was obtained in the same manner as in the production example of toner 1. Table 4 shows the physical properties of the obtained toners 4 to 6 and 15.

[0448] <Production Examples of Toners 7 to 9>

[0449] Except for replacing aluminum chloride, which is added as an agglomerating agent, with magnesium chloride and changing the amount added as shown in Table 4, each of toners 7 to 9 is obtained in the same manner as in the production example of toner 1. Table 4 shows the physical properties of the obtained toners 7 to 9.

[0450] <Production Examples of Toners 10 and 11>

[0451] Except for replacing the aluminum chloride added as an agglomerating agent with calcium chloride and changing the amount added as shown in Table 4, each of toners 10 and 11 was obtained in the same manner as in the production example of toner 1. Table 4 shows the physical properties of the obtained toners 10 and 11.

[0452] <Production Examples of Toners 12 to 14 and 16>

[0453] Except that the aluminum chloride added as an agglomerating agent is changed to ferric chloride (III) and the addition amount is changed as shown in Table 4, each of toners 12 to 14 and 16 is obtained in the same manner as in the production example of toner 1. Table 4 shows the physical properties of the obtained toners 12 to 14 and 16.

[0454] <Example 1>

[0455] A commercially available color laser printer, the HP LaserJet Enterprise Color m553dn, was used, with some modifications. The modification involved changing the main unit's processing speed to 300 mm / sec and making necessary adjustments to enable image formation under these conditions.

[0456] Furthermore, the toner was removed from the black toner cartridge and then 320g of toner 1 was refilled. Additionally, the photosensitive element was changed to the photosensitive element 1 disclosed herein. The resulting toner cartridge was installed in a black station, and dummy cartridges were installed in other stations, and the following image output tests were conducted. The evaluation results for evaluations 1 to 3 are shown in Table 5.

[0457] (Evaluation 1: Grayscale evaluation under high temperature and high humidity environment)

[0458] The printer was loaded with Office70 (manufactured by Canon Inc.) as media, and 10,000 sheets of character pattern images with a print rate of 1% were fed through at 30.0°C / 80%RH. The printer was then fed in a mode where it was set to 2 sheets per job, pausing once between jobs before the next job began.

[0459] After paper passage, the output has Figure 3 The images shown are patterns 1 to 8, representing the grayscale of the image concentration. The concentration of each image was measured using an XRite color reflectance darkness meter (X-Rite 404A) to determine the grayscale.

[0460] In this evaluation, the image is output as a black monochrome. From the viewpoint of grayscale reproducibility, the density range of each pattern image is preferably within the following range, and the evaluation is conducted from this viewpoint.

[0461] Pattern 1: 0.10 or higher and less than 0.15

[0462] Pattern 2: 0.15 or higher and less than 0.20

[0463] Pattern 3: 0.20 or higher and less than 0.30

[0464] Pattern 4: 0.25 or higher and less than 0.40

[0465] Pattern 5: 0.55 or higher and less than 0.70

[0466] Pattern 6: 0.65 or higher and less than 0.80

[0467] Pattern 7: 0.75 or higher and less than 0.90

[0468] Pattern 8: 1.40 and above

[0469] (Evaluation Criteria)

[0470] A: All pattern images meet the above concentration range.

[0471] B: A pattern image is outside the above concentration range.

[0472] C: Both pattern images are outside the above concentration range.

[0473] D: Three or more pattern images outside the above concentration range.

[0474] E: Four or more pattern images outside the above concentration range.

[0475] In this case, the highest acceptable level of effect is D.

[0476] (Evaluation 2: Fogging evaluation under high temperature and high humidity environment)

[0477] Load the printer with XEROX 4200 paper (manufactured by Xerox Corporation, 75 g / m²) as the medium. 2 At 30.0°C / 80% RH, each sheet of paper with a sticky note covering a portion of the printed surface to which the image is pasted is used to output a completely white image (white image 1). Then, 10,000 sheets of character pattern images with a print rate of 1% are passed through. At this time, the printer is fed in a mode where it is set to 2 sheets / job, pausing once between jobs before the start of the next job. After 10,000 sheets have passed through, the printer is left to stand for 3 days, and then each sheet of paper with a sticky note covering a portion of the printed surface to which the image is pasted is used to output a completely white image (white image 2).

[0478] After removing the sticky note from the white image 1, the reflectance (%) of the part with the sticky note and the reflectance (%) of the unsticky part were measured at 5 points to obtain the average value, and then the difference was calculated and used as the initial fogging value.

[0479] Furthermore, for white image 2, the difference in average values ​​was calculated in the same manner and used as the post-durability fogging. The difference between initial fogging and post-durability fogging was calculated, and the post-durability fogging was evaluated using the following evaluation criteria.

[0480] In addition, reflectance was measured using a digital white photometer (TC-6D type manufactured by Tokyo Denshoku, Co., Ltd., with a green filter).

[0481] (Evaluation Criteria)

[0482] A: The difference in fogging between the initial stage and after durability is less than 0.5%.

[0483] B: The difference in fogging between the initial stage and after durability testing is greater than 0.5% but less than 1.5%.

[0484] C: The difference in fogging between the initial stage and after durability is greater than 1.5% but less than 2.5%.

[0485] D: The difference in fogging between the initial stage and after durability is more than 2.5%.

[0486] In this case, the highest acceptable level of effect is C.

[0487] (Evaluation 3: Fogging evaluation in low temperature and low humidity environments)

[0488] Fogging was evaluated after continuous use in a low-temperature, low-humidity environment (15°C / 10% RH). XEROX 4200 paper (manufactured by Xerox Corporation, 75 g / m²) was used. 2 (As an evaluation paper)

[0489] In a low-temperature, low-humidity environment, each sheet of paper with a sticky note covering a portion of the printed surface to which the image is attached is used to output a completely white image (white image 3). Then, 10,000 sheets of character pattern images with a 1% print rate are passed through. At this point, the paper is fed in a mode where the printer is set to 2 sheets per job, pausing once between jobs before the start of the next job. Afterward, each sheet of paper with a sticky note covering a portion of the printed surface to which the image is attached is again used to output a completely white image (white image 4).

[0490] After removing the sticky notes from the white image 3, the reflectance (%) was measured at 5 points for both the sticky note-covered and unsticky notes-covered areas. The average reflectance was calculated, and the difference was used as the initial fogging value.

[0491] Furthermore, for white image 4, the difference in average values ​​was calculated in the same manner and used as the post-durability fogging. The difference between initial fogging and post-durability fogging was calculated, and the post-durability fogging was evaluated using the following evaluation criteria.

[0492] In addition, reflectance was measured using a digital white photometer (TC-6D type manufactured by Tokyo Denshoku, Co., Ltd., with a green filter).

[0493] (Evaluation Criteria)

[0494] A: The difference in fogging between the initial stage and after durability is less than 0.5%.

[0495] B: The difference in fogging between the initial stage and after durability testing is greater than 0.5% but less than 1.5%.

[0496] C: The difference in fogging between the initial stage and after durability is greater than 1.5% but less than 2.5%.

[0497] D: The difference in fogging between the initial stage and after durability is more than 2.5%.

[0498] In this case, the highest acceptable level of effect is C.

[0499] <Examples 2 to 26, Comparative Examples 1 to 6>

[0500] Except for changing the combination of the electrophotographic photosensitive element and toner as shown in Table 5, each image output experiment was conducted in the same manner as in Example 1, and the experiments were evaluated 1 to 3. The evaluation results for each evaluation are shown in Table 5.

[0501]

[0502] According to this disclosure, a processing box can be provided that suppresses fogging regardless of the usage environment and is capable of forming images with excellent grayscale.

[0503] While this disclosure has been described with reference to exemplary embodiments, it should be understood that this disclosure is not limited to the disclosed exemplary embodiments. The scope of the appended claims is to be accorded the broadest interpretation, thereby covering all such modifications and equivalent structures and functions.

Claims

1. A processing box detachably mounted to the body of an electrophotographic device, The processing box includes: Electrophotographic photosensitive components; and A developing unit comprising a toner storage section for containing toner and supplying the toner to the surface of the electrophotographic photosensitive element, characterized in that, The electrophotographic photosensitive component has a conductive support and a photosensitive layer and a surface protective layer sequentially formed on the conductive support, wherein... The surface protective layer contains conductive particles. The content of the conductive particles is more than 20.0% by volume and less than 70.0% by volume of the total volume of the surface protective layer. The volume resistivity of the surface protective layer is 1.0 × 10⁻⁶. 9 Ω·cm or more and 1.0×10 14 Below Ω·cm, The toner contained in the toner storage section has toner particles comprising a binder resin and external additives. The toner particles contain at least one multivalent metal element selected from the group consisting of aluminum, magnesium, calcium, and iron, and The total content of the polyvalent metal elements in the toner particles, as determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), is above 0.10 μmol / g and below 1.25 μmol / g.

2. The processing box according to claim 1, wherein, Regarding the polyvalent metal elements contained in the aforementioned toner particles, The aluminum content is below 0.50 μmol / g; The magnesium content is below 0.80 μmol / g; The calcium content is below 0.90 μmol / g; The iron content is below 1.25 μmol / g, and The total content of these polyvalent metal elements is above 0.10 μmol / g and below 1.25 μmol / g.

3. The processing box according to claim 1, wherein the toner particles contain aluminum as the polyvalent metal element at a concentration of 0.10 μmol / g or more and 0.32 μmol / g or less.

4. The processing cartridge of claim 1, wherein the toner particles comprise wax, and the wax is an ester compound.

5. The processing box according to claim 1, wherein a carboxyl group is present in the molecular chain constituting the adhesive resin, and the carboxyl group forms a coordination bond with the multivalent metal element and is present in the toner particles.

6. The processing box according to claim 1, wherein the toner particles are emulsified aggregated toner particles.

7. The processing box according to claim 1, wherein the conductive particles are titanium dioxide particles.

8. The processing box according to claim 7, wherein the titanium dioxide particles are titanium dioxide particles containing niobium atoms.

9. The processing box according to claim 8, wherein, In the niobium-containing titanium oxide particles, the concentration ratio calculated as the niobium atom concentration / titanium atom concentration within 5% of the maximum diameter of the particle measured from the particle surface is more than 2.0 times the concentration ratio calculated as the niobium atom concentration / titanium atom concentration at the center of the particle.

10. The processing box according to claim 8, wherein the niobium-containing titanium oxide particles contain 2.6% by mass and less than 10.0% by mass of niobium atoms.

11. The processing box according to claim 1, wherein, In the electrophotographic photosensitive element, The content of the conductive particles is more than 40.0% by volume and less than 70.0% by volume of the surface protective layer, and The volume resistivity of the surface protective layer is 1.0 × 10⁻⁶. 10 Ω·cm or more and 1.0×10 14 Below Ω·cm.

Images