JP7328027B2 - image forming device - Google Patents

Description

The present invention relates to an image forming apparatus. Here, the image forming apparatus forms an image on a recording material (recording medium) using an electrophotographic image forming system. Examples of image forming apparatuses include copiers, printers (laser beam printers, LED printers, etc.), facsimile machines, word processors, and multifunction machines (multifunction printers).

2. Description of the Related Art Conventionally, organic photoreceptors have been widely used as electrophotographic photoreceptors (hereinafter also simply referred to as "photoreceptors") used in electrophotographic image forming apparatuses due to their advantages of low cost and high productivity. This is constituted by providing a photosensitive layer (organic photosensitive layer) using an organic material as a photoconductive substance (charge-generating substance or charge-transporting substance) on a support.

Since the photoreceptor is directly subjected to external electrical and mechanical forces in the steps of charging, exposure, development, transfer, and cleaning, durability against these external forces is required. Specifically, it is required to have durability against occurrence of scratches and wear on the surface due to these external forces, that is, scratch resistance and wear resistance.

However, when the abrasion of the photoreceptor is suppressed, the surface of the photoreceptor becomes difficult to refresh, and blurring of the electrostatic latent image called "image deletion" tends to occur particularly in a high humidity environment. Image deletion is mainly caused by a decrease in the surface resistance of the photoreceptor due to the adherence of discharge products such as ozone and NOx, which are generated on the surface of the photoreceptor due to charging, to the surface of the photoreceptor. do. If the friction coefficient of the surface of the photoreceptor is reduced and the hardness thereof is increased in order to suppress abrasion of the photoreceptor, the surface becomes less likely to be abraded and the discharge products adhering to the surface are less likely to be removed. As a result, the discharge products adhering to the surface of the photoreceptor absorb moisture in a high-humidity environment to lower the resistance, lowering the charge retention capacity of the surface of the photoreceptor and causing image deletion.

As a method for preventing the occurrence of image deletion, Patent Document 1 proposes a method in which metallic soap is added to the developer and the metallic soap is supplied from the developer carrying member to the surface of the photoreceptor. In this method, zinc stearate, which is a metal soap, is supplied to the surface of the photoreceptor from a developer carrier, and the surface of the photoreceptor is coated with zinc stearate to suppress the adhesion of discharge products and prevent image deletion. preventing it from occurring.

JP-A-2005-121833

However, the metal soap supplied onto the photoreceptor by the method of Patent Document 1 is scraped off by a member such as a cleaning means that is in contact with the photoreceptor due to the rotation of the photoreceptor, resulting in image deletion. something happened.

In view of the above circumstances, an object of the present invention is to suppress the occurrence of image deletion by maintaining the amount of metal soap on the surface of the photoreceptor.

In order to achieve this object, the image forming apparatus of the present invention is an image forming apparatus for forming a toner image on a recording material. The range of the ten-point average surface roughness (Rz) of the surface of the image carrier is 0.10≦Rz≦0.70 (μm), and the range of the average spacing (Sm) of the unevenness of the surface of the image carrier. is 0<Sm≦70 (μm), a charging member that charges the surface of the image carrier, a toner containing portion that contains toner containing metallic soap, and faces the image carrier. a developing member for forming a toner image by supplying the toner to the surface of the image carrier charged by the charging member in the developing section, and a surface moving speed of the developing member corresponding to a surface moving speed of the image carrier; an image forming operation for forming the toner image on a recording material; and applying the metallic soap to the surface of the image carrier by supplying the toner contained in the toner container from the developing member to the surface of the image carrier , which is different from the image forming operation. and a coating operation, wherein the control unit controls the speed difference between the surface moving speed of the developing member and the surface moving speed of the image bearing member in the coating operation so that the speed difference in the image forming operation is The speed difference is controlled to be greater than the speed difference.

According to the present invention, image deletion can be suppressed by maintaining the amount of metal soap on the surface of the photoreceptor.

1 is a schematic cross-sectional view of an image forming apparatus in Example 1. FIG. 4 is a cross-sectional view of the process cartridge in Example 1. FIG. 2 is a schematic block diagram showing a control mode of the image forming apparatus according to Embodiment 1; FIG. 1 is a schematic diagram of toner in Example 1. FIG. 2 is a flow chart diagram in Example 1. FIG. FIG. 10 is a schematic diagram of a roughened surface of a photoreceptor in Example 3; 3 is a schematic diagram of a polishing apparatus for polishing the surface of a photoreceptor in Example 3. FIG. 4 is a conceptual diagram of the surface layer thickness of a surface layer containing an organosilicon compound in Example 4. FIG.

Exemplary embodiments of the invention will now be described with reference to the drawings. In addition, the following embodiments are examples, and the present invention is not limited to the contents of the embodiments. Also, in the following drawings, constituent elements that are not necessary for the description of the embodiments are omitted from the drawings.

1. Image Forming Apparatus The overall configuration of the electrophotographic image forming apparatus in this embodiment will be described. FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 of Example 1. FIG. The image forming apparatus 100 of the first embodiment is a full-color laser printer that employs an in-line method and an intermediate transfer method. The image forming apparatus 100 can form a full-color image on a recording material S (for example, recording paper, plastic sheet, cloth, etc.) according to image information. Image information is sent to the image forming apparatus 100 from an image reading device (not shown) connected to the image forming apparatus 100 or a host device (not shown) such as a personal computer communicably connected to the image forming apparatus 100 . is entered.

Image forming apparatus 100 includes first, second, and third image forming units for forming yellow (Y), magenta (M), cyan (C), and black (K) images, respectively, as a plurality of image forming units. , and fourth image forming units SY, SM, SC, and SK.

In Embodiment 1, the image forming apparatus 100 has four drum-type electrophotographic photosensitive members (hereinafter referred to as photosensitive members 1) arranged side by side in a direction intersecting the vertical direction as a plurality of image carriers. A process cartridge 7 is formed by integrating the body 1 and the image forming section.
A photoreceptor 1 as an image carrier that carries an electrostatic latent image is rotationally driven by driving means (not shown). The charging roller 2 as a charging member is a single-layer roller composed of a conductive metal core and a conductive rubber layer, and has an outer diameter of φ7.5 mm and a volume resistivity of 10 ³ to 10 ⁶ Ω·cm. A charging voltage of -1000 V is applied to the charging roller 2 by a charging high voltage 71, which is a charging voltage applying section as a high voltage power source to be described later, so that the surface of the photoreceptor 1 is uniformly charged to -500 V. A DC (direct current) voltage of Vd+Vth is applied to the charging roller 2, and the photosensitive member 1 is uniformly charged at the charging potential Vd by discharging. Vd at this time is called a dark potential and is -500V. Vth is a discharge start voltage. When the applied charging voltage is small, the surface potential on the photoreceptor 1 does not increase due to discharge, but the surface potential starts to increase due to discharge from the discharge start voltage Vth. That is, the discharge start voltage Vth in this embodiment is -500V.

After the surface of the photoreceptor 1 is charged by the charging roller 2 , the surface of the photoreceptor 1 is irradiated with laser light from the exposure unit 30 . The exposure unit 30 is exposure means for forming an electrostatic latent image on the surface of the photoreceptor 1 by irradiating a laser based on image information. The surface potential of the photoreceptor 1 irradiated with the laser beam changes to -100 V as Vl, which is the light potential, and an electrostatic latent image is formed.

FIG. 2 is a cross-sectional view of the process cartridge 7 of Example 1 viewed along the longitudinal direction (rotational axis direction) of the photoreceptor 1. As shown in FIG. The process cartridge 7 is composed of the developing unit 3 and the photoreceptor unit 13 . In the developing unit 3, a developing roller 4 as a developing member and a toner supply roller (hereinafter referred to as "supply roller") 5 as a toner supply member are arranged. By receiving the driving force of a drive motor (not shown), the developing roller 4 and the supply roller 5 start rotating in the direction of arrow D in FIG. 2 and the direction of arrow R in FIG. 2, respectively. Then, a voltage of −300 V is applied as a development voltage from the development high voltage 72 as a development voltage applying section to the development roller 4, whereby an electrostatic latent image is formed on the surface of the photoreceptor 1, that is, Vl A developer (toner) is supplied to the portion by the developing roller 4 for development.

A developer image (toner image) developed on the surface of the photoreceptor 1 is transferred to the intermediate transfer belt 31 shown in FIG. An intermediate transfer belt 31 formed of an endless belt as an intermediate transfer member for transferring the toner image on the photoreceptor 1 onto the recording material S faces the photoreceptor 1 of each image forming section. It abuts on the photoreceptor 1 of the forming portion and circulates (rotates) in the direction of arrow B (counterclockwise) in FIG.

Primary transfer rollers 32 , which are transfer members as primary transfer means, are arranged on the inner peripheral surface side of the intermediate transfer belt 31 so as to face the photoreceptors 1 . A primary transfer voltage power supply (primary transfer high voltage) 73 serving as a primary transfer voltage applying section applies a voltage having a polarity opposite to the normal charging polarity of the toner to the primary transfer roller 32 . As a result, the toner image on the photosensitive member 1 is transferred (primary transfer) onto the intermediate transfer belt 31 . As for the polarity of the toner in the present embodiment, the normal polarity is the negative polarity. Therefore, primary transfer can be performed by applying a positive voltage as the primary transfer voltage.

A secondary transfer roller 33 as a secondary transfer unit is arranged on the outer peripheral surface side of the intermediate transfer belt 31 . A voltage having a polarity opposite to that of the toner is applied to the secondary transfer roller 33 from a secondary transfer voltage power supply (secondary transfer high voltage) 74 as a secondary transfer voltage applying section. As a result, the toner image on the intermediate transfer belt 31 is transferred to the recording material S (secondary transfer). For example, when forming a full-color image, the above process is sequentially performed in the image forming stations SY, SM, SC, and SK, and the toner images of each color are sequentially superimposed and primary transferred onto the intermediate transfer belt 31 . After that, the recording material S is conveyed to the secondary transfer portion in synchronization with the movement of the intermediate transfer belt 31 . Then, the four-color toner images on the intermediate transfer belt 31 are collectively secondary-transferred onto the recording material S by the action of the secondary transfer roller 33 which is in contact with the intermediate transfer belt 31 via the recording material S. be.

The recording material S onto which the toner image has been transferred is conveyed to the fixing device 34 . By applying heat and pressure to the recording material S in the fixing device 34 , the toner image is fixed on the recording material S, and the recording material S is discharged outside the image forming apparatus 100 .

On the other hand, the surface potential of the photoreceptor 1 after transferring the toner onto the intermediate transfer belt 31 is non-uniform due to the primary transfer voltage. Therefore, by exposing the entire surface of the photoreceptor 1 (to irradiate the entire surface with light) by the pre-exposure unit 27, which is a pre-exposure unit, the surface potential of the photoreceptor 1, which has become uneven due to the previous image formation, is made uniform. vinegar. That is, the surface of the photoreceptor 1 is irradiated with light so as to remove residual charges on the surface of the photoreceptor 1 . The pre-exposure unit 27 is located downstream of the transfer unit, which is the contact position between the intermediate transfer belt 31 and the photoreceptor 1, in the rotation direction of the photoreceptor 1, and from the charging unit, which is the contact position between the charging roller 2 and the photoreceptor 1. is disposed between the photoreceptors 1 on the upstream side in the rotational direction, and exposes the surface of the photoreceptor 1, which is the opposing portion. As a light source for the pre-exposure unit 27, an LED, a halogen lamp, or the like can be used. Although the light source to be used is not particularly limited, it is preferable to use an LED from the viewpoint of low driving voltage and easy miniaturization of the device.

Further, the toner remaining on the surface of the photoreceptor 1 without being transferred by the primary transfer roller 32 is scraped off from the surface of the photoreceptor 1 by the cleaning blade 8 in contact with the photoreceptor 1, and is provided below the cleaning blade 8. The toner is stored in the waste toner storage chamber 9 . Toner remaining on the intermediate transfer belt 31 without being transferred onto the recording material S by the secondary transfer roller 33 is conveyed to an intermediate transfer member cleaning device 35 as a cleaning device and removed.

2. Control Mode of Image Forming Apparatus FIG. 3 is a block diagram showing a schematic control mode of the main part of the image forming apparatus 100 in this embodiment. A control unit 202 is means for controlling the operation of the image forming apparatus 100, and transmits and receives various electrical information signals. It also processes electrical information signals input from various process equipment and sensors, and processes command signals to various process equipment. The controller 200 exchanges various electrical information with the host apparatus, and controls the image forming operation of the image forming apparatus 100 by the control unit 202 via the interface 201 according to a predetermined control program and reference table. control. The control unit 202 includes a CPU 155 which is a central element for performing various arithmetic processing, a memory 15 such as a RAM and a ROM which are storage elements, and the like. The RAM stores sensor detection results, counter count results, calculation results, and the like, and the ROM stores control programs, data tables obtained in advance through experiments, and the like. Control objects, sensors, counters, and the like in the image forming apparatus 100 are connected to the control unit 202 . A control unit 202 controls the transmission and reception of various electrical information signals, the timing of driving each unit, and the like, thereby controlling a predetermined image forming sequence. For example, in order to form a toner image on the surface of the photoreceptor 1, the following high voltage power supply and devices are controlled. A charging high voltage 71 as a charging power source, a developing high voltage 72 as a developing power source, a supply high voltage 75 as a power source for the supply roller 5 that supplies the toner supply voltage, a developing blade high voltage 76 as a power source for the developing blade 6 as a toner regulating member, and exposure. It controls the unit 30 and the like. Further, a primary transfer high voltage 73 as a primary transfer power source and a secondary transfer high voltage 74 as a secondary transfer power source for forming a toner image on the recording material S are controlled. In addition, it controls the contact/separation mechanism 50 that controls the contact/separation between the developing roller 4 and the photoreceptor 1 . In this embodiment, the control unit 202 controls the high pressure and the like in order to perform the metallic soap coating operation, which will be described later in detail.

3. Schematic Configuration of Process Cartridge The overall configuration of the process cartridge 7 installed in the image forming apparatus 100 of the first embodiment will be described with reference to FIG. The process cartridge 7 is attachable to and detachable from the image forming apparatus 100 via a mounting means such as a mounting guide and a positioning member (not shown) provided in the image forming apparatus 100 . In Embodiment 1, the process cartridges 7 for each color have the same shape, and the process cartridges 7 for each color contain yellow (Y), magenta (M), cyan (C), black (K), respectively. ) are stored therein. Although the process cartridge 7 will be described in the first embodiment, the developing unit 3 may be configured to have a developing cartridge that can be attached to and detached from the image forming apparatus 100 by itself.

In Embodiment 1, the configuration and operation of the process cartridges 7 for each color are substantially the same except for the type (color) of the toner 10 contained therein.

The process cartridge 7 has a developing unit 3 having a developing roller 4 and the like and a photoreceptor unit 13 having the photoreceptor 1 .

In the present embodiment, the developing unit 3 and the photosensitive member unit 13 are integrated into the process cartridge 7, but the present invention is not limited to this. .

The developing unit 3 is roughly divided into a developing chamber 3a and a toner container 3b. A toner conveying member 22 for conveying the toner 10 to the developing chamber 3a is provided in the toner containing portion 3b. there is

The developing chamber 3a is provided with a developing roller 4 as a toner carrying member that contacts the photoreceptor 1 and rotates in the direction of arrow D in the drawing. In Example 1, the developing roller 4 and the photoreceptor 1 rotate so that their surfaces move in the same direction in the developing portions facing each other.

Further, inside the developing chamber 3a, there are provided a supply roller 5 for supplying the developing roller 4 with the toner 10 conveyed from the toner containing portion 3b, and a coating amount control roller for the toner 10 supplied from the supply roller 5 onto the developing roller 4. and a toner regulating member 6 for imparting electric charge.

Independent voltages are applied to the developing roller 4, the supply roller 5, and the toner regulating member 6 from a high-voltage power supply. The toner 10 supplied to the developing roller 4 by the supplying roller 5 is triboelectrically charged by rubbing between the developing roller 4 and the toner regulating member 6, and the layer thickness is regulated at the same time as being charged. The regulated toner 10 on the developing roller 4 is conveyed to the portion facing the photoreceptor 1 by the rotation of the developing roller 4, and the electrostatic latent image on the photoreceptor 1 is developed and visualized as a toner image.

In the present invention, the prescribed DC voltage (development voltage: Vdc) applied to the developing roller 4 is -300V. Further, by applying a voltage (supply voltage: Vr=−250 V) to the supply roller 5, the potential difference (ΔVr) between the supply roller 5 and the developing roller 4 is adjusted, and the amount of toner 10 supplied to the developing roller 4 is adjusted. can be adjusted. In this embodiment, ΔVr=Vdc-Vr is set to -50V.

In the first embodiment, when the electrostatic latent image on the photoreceptor 1 is developed and visualized as a toner image, the developing roller 4 is rotationally driven so as to be in contact with the peripheral surface of the photoreceptor 1 . This is for the purpose of facilitating the supply of metal soap externally added to the toner, which will be described later, onto the photoreceptor 1 . The structure is not limited to the structure in which the developing roller 4 and the photosensitive member 1 are in contact with each other, as long as the structure can supply metallic soap.

Here, in the following description, with respect to the potential and applied voltage, a large absolute value on the negative side (for example, -1000 V for -500 V) is referred to as a high potential, and a small absolute value on the negative side ( For example, -300V for -500V) is called a low potential. This is because the negatively charged toner 10 in this embodiment is taken as a reference.

Also, the voltage in this embodiment is expressed as a potential difference from the ground potential (0 V). Therefore, the development voltage of -300 V is interpreted as having a potential difference of -300 V with respect to the ground potential due to the development voltage applied to the core metal of the development roller 4 . This is the same for other voltages such as charging voltage.

The photosensitive member 1 is rotatably attached to the photosensitive member unit 13 via a bearing (not shown). Photoreceptor 1 is rotationally driven in the direction of arrow A in FIG. 2 by receiving the driving force of a drive motor (not shown). A charging roller 2 and a cleaning blade 8 as a plate-shaped elastic member are arranged in the photoreceptor unit 13 so as to be in contact with the peripheral surface of the photoreceptor 1 . One end of the cleaning blade 8 is fixed to a plate-like metal plate, and the other free end abuts against the photoreceptor 1 to form a cleaning nip, which is a contact portion with the photoreceptor 1 . By rubbing the surface of the photoreceptor 1 with a cleaning blade 8 to scrape off the toner 10 and fine particles remaining in the transfer process and storing them in the waste toner storage chamber 9, contamination of the charging roller 2 and toner on the photoreceptor 1 can be prevented. 10 to prevent image damage due to the accompanying rotation.

4. Structure of Photoreceptor Photoreceptor 1 comprises a cylindrical conductive metal support, a conductive layer as an undercoat layer of the support, and a photosensitive layer (charge generation layer, charge transport layer) formed on the undercoat layer. ) and a protective layer formed on the photosensitive layer. The photoreceptor 1 is composed of a photosensitive material such as OPC (organic photo-semiconductor), amorphous selenium, amorphous silicon, etc., provided on a drum substrate on a cylinder made of aluminum, nickel or the like and having an outer diameter of φ24 mm as a support. It is. Further, the photoreceptor 1 in this embodiment is provided with an abrasion-resistant protective layer as the outermost layer in order to improve abrasion resistance. Durability can be improved by providing a protective layer.

The protective layer preferably contains conductive particles and/or a charge transport material and a resin. Conductive particles include particles of metal oxides such as titanium oxide, zinc oxide, tin oxide, and indium oxide. 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.

Examples of resins include polyester resins, acrylic resins, phenoxy resins, polycarbonate resins, polystyrene resins, phenol resins, melamine resins, and epoxy resins. Among them, polycarbonate resins, polyester resins, and acrylic resins are preferred.

Alternatively, the protective layer may be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group. The reaction at that time includes thermal polymerization reaction, photopolymerization reaction, radiation polymerization reaction, and the like. Examples of the polymerizable functional group possessed by the monomer having a polymerizable functional group include an acrylic group and a methacrylic group. A material having charge transport ability may be used as the monomer having a polymerizable functional group.

The protective layer may contain additives such as an antioxidant, an ultraviolet absorber, a plasticizer, a leveling agent, a lubricating agent, and an abrasion resistance improver. Specifically, hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane-modified resins, silicone oils, fluororesin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, boron nitride particles. etc. The average film thickness of the protective layer is preferably 0.5 μm or more and 10 μm or less, and more preferably 1 μm or more and 7 μm or less.

The protective layer can be formed by preparing a protective layer coating liquid containing each of the materials and solvents described above, forming a coating film thereon, and drying and/or curing the coating film. Solvents used in the coating liquid include alcohol solvents, ketone solvents, ether solvents, sulfoxide solvents, ester solvents, and aromatic hydrocarbon solvents. In Example 1, the average film thickness of the protective layer was set to 3 μm.

5. Structure of Toner FIG. 4 shows a schematic diagram of the toner 10 used in Example 1. As shown in FIG. In Example 1, the inorganic particle externally added toner 45 is used in which the inorganic silicon 45b is externally added to the mother particles 45a to secure fluidity and improve chargeability. The toner used in Example 1 is a non-magnetic one-component particle-polymerized toner having a negatively charged polarity, and has an average particle size of 7 μm.

Furthermore, in addition to the inorganic silicon 45b, a metallic soap 45c is externally added for the purpose of suppressing image deletion. By supplying the metal soap 45c to the photosensitive member 1 to form a protective film, it is possible to reduce adhesion of discharge products and the like. When the discharge product contains moisture, the resistance decreases. Therefore, the surface of the photoreceptor 1 to which the discharge products adhere has a low resistance. By supplying the metal soap 45c to the surface of the photoreceptor 1, it is possible to suppress the occurrence of image deletion caused by the surface resistance of the photoreceptor 1 being lowered.

Metal soap 45c is a general term for long-chain fatty acids and metal salts other than sodium and potassium. Specific examples include metal salts of fatty acids such as stearic acid, myristic acid, lauric acid, ricinoleic acid and octylic acid and metal species such as lithium, magnesium, calcium, barium and zinc. In Example 1, zinc stearate is externally added as the metal soap 45c. The types of metal soap 45c are not limited to these, and lead stearate, cadmium stearate, barium stearate, calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, zinc laurate, and myristine. Zinc acid may also be used as appropriate, and at least one of these may be selected.

The external addition amount of the metal soap 45c is desirably 0.6 wt % or less. The greater the amount of the external additive added, the more effective it is in suppressing the image flow. This is a phenomenon called solid follow-up failure, in which follow-up performance deteriorates toward the trailing edge when outputting a solid black image. On the other hand, it is desirable that the external addition amount of the metal soap 45c is 0.05 wt % or more. If the amount is too small, the effect of the metal soap 45c will be less likely to be exhibited.

The average particle diameter of the metal soap 45c is preferably 0.15 μm or more and 2.0 μm or less. If the average particle diameter of the metal soap 45c is smaller than 0.15 μm, it becomes difficult to apply it to the surface of the photoreceptor 1 . In particular, it becomes noticeable when the surface of the photoreceptor 1, which will be described later, has grooves. On the other hand, if the particle size is larger than 2.0 μm, the toner cannot pass through the toner regulating member 6 in the developing unit 3 and is left behind in the developing chamber 3 a , making it difficult to supply the surface of the photoreceptor 1 . Hereinafter, the term "toner" used in this embodiment will collectively refer to the toner base particles 45a and the external additive as general toner.

A method for measuring the average particle size of the metal soap 45c will be described. 10 mL of ethanol was added to 0.5 g of metallic soap 45c, and ultrasonically dispersed for 5 minutes using an ultrasonic disperser manufactured by Nippon Seiki Co., Ltd. Next, ethanol is circulated as a measurement solvent. Then, the obtained dispersion of metallic soap 45c was measured on a Microtrac Laser Diffraction/Scattering Particle Size Distribution Analyzer (SPA type) manufactured by Nikkiso Co., Ltd. DV (diffracted light amount), which is a value related to the integrated value of scattered light amount of particles, was measured. Add until the value is 0.6-0.8. Then, the particle size distribution in this state was measured, and the median diameter obtained as the cumulative median diameter of 50% diameter was taken as the average particle diameter.

The metal soap 45c having the above average particle diameter may be produced, for example, by using a double decomposition method in which a fatty acid salt aqueous solution and an inorganic metal salt aqueous solution or dispersion are allowed to react.

In this example, zinc stearate having an average particle size of 0.60 μm was used. Zinc stearate as the metal soap 45c is attached to the toner particles by being charged to the opposite polarity of the toner, and supplied onto the photoreceptor 1 during non-image formation.

Next, a method for producing toner particles will be described. A known means can be used as a method for producing toner particles, and a kneading pulverization method or a wet production method can be used. A wet production method is preferable from the viewpoint of uniformity of particle size and shape controllability. Furthermore, as the wet production method, a suspension polymerization method, a dissolution suspension method, an emulsion polymerization aggregation method, an emulsion aggregation method, or the like may be used.

In this example, a suspension polymerization method will be described. In the suspension polymerization method, first, a polymerizable monomer for forming a binder resin and, if necessary, other additives such as a colorant are added using a dispersing machine such as a ball mill or an ultrasonic dispersing machine. A polymerizable monomer composition is prepared by uniformly dissolving or dispersing these components. This step is referred to as a step of preparing a polymerizable monomer composition. At this time, if necessary, a polyfunctional monomer, a chain transfer agent, a wax as a release agent, a charge control agent, a plasticizer, and the like can be appropriately added. As the polymerizable monomer in the suspension polymerization method, the following vinyl-based polymerizable monomers can be preferably exemplified.

Styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, p- styrene derivatives such as n-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene; methyl acrylate; , ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n - acrylic polymerizable monomers such as nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; methyl methacrylate, ethyl methacrylate , n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate , diethyl phosphate ethyl methacrylate, methacrylic polymerizable monomers such as dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, vinyl benzoate, vinyl esters such as vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropyl ketone.

Next, the polymerizable monomer composition is put into an aqueous medium prepared in advance, and droplets of the polymerizable monomer composition are formed by a stirrer or a disperser having a high shear force. Form the desired toner particle size. This process is called a granulation process. It is preferable that the aqueous medium in the granulation step contains a dispersion stabilizer in order to control the particle size of the toner particles, sharpen the particle size distribution, and suppress coalescence of the toner particles in the production process. Dispersion stabilizers are generally classified broadly into macromolecules that generate a repulsive force due to steric hindrance and poorly water-soluble inorganic compounds that stabilize dispersion by electrostatic repulsive force. Fine particles of poorly water-soluble inorganic compounds are preferably used because they dissolve in acids or alkalis and can be dissolved and easily removed by washing with acids or alkalis after polymerization.

As the dispersion stabilizer for the sparingly water-soluble inorganic compound, one containing any one of magnesium, calcium, barium, zinc, aluminum and phosphorus is preferably used. More preferably, one of magnesium, calcium, aluminum and phosphorus is desired. Specifically, the following are mentioned.

Magnesium phosphate, tricalcium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, hydroxyapatide.

Organic compounds such as polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salts of carboxymethyl cellulose, and starch may be used in combination with the dispersion stabilizer. It is preferable to use 0.01 parts by mass or more and 2.00 parts by mass or less of these dispersion stabilizers with respect to 100 parts by mass of the polymerizable monomer.

Furthermore, in order to make these dispersion stabilizers finer, 0.001 parts by mass or more and 0.1 parts by mass or less of a surfactant may be used together with 100 parts by mass of the polymerizable monomer. Specifically, commercially available nonionic, anionic, and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate and calcium oleate are preferably used.

After the granulation step or while performing the granulation step, the temperature is preferably set to 50° C. or higher and 90° C. or lower to polymerize the polymerizable monomer contained in the polymerizable monomer composition to obtain a toner. A particle dispersion is obtained. This process is called a polymerization process. In the polymerization step, it is preferable to perform a stirring operation so that the temperature distribution in the container becomes uniform. When the polymerization initiator is added, it can be added at any desired timing and required time. Further, in order to obtain a desired molecular weight distribution, the temperature may be raised in the second half of the polymerization reaction, and further, in order to remove unreacted polymerizable monomers, by-products, etc. from the system, the second half of the reaction or the end of the reaction may be heated. Afterwards, a portion of the aqueous medium may be distilled off by a distillation operation. The distillation operation can be performed under normal pressure or reduced pressure.

An oil-soluble initiator is generally used as the polymerization initiator used in the suspension polymerization method. For example:

2,2'-azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4 - azo compounds such as methoxy-2,4-dimethylvaleronitrile; acetylcyclohexylsulfonyl peroxide, diisopropyl peroxycarbonate, decanonyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl peroxide, acetyl peroxide, tert- Butyl peroxy-2-ethylhexanoate, benzoyl peroxide, tert-butyl peroxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, tert-butyl hydroperoxide, di-tert-butylperoxide peroxide initiators such as oxide, tert-butyl peroxypivalate and cumene hydroperoxide;
If necessary, a water-soluble initiator may be used in combination with the polymerization initiator, and examples thereof include the following.

ammonium persulfate, potassium persulfate, 2,2'-azobis(N,N'-dimeleneisobutyroamidine) hydrochloride, 2,2'-azobis(2-aminodinopropane) hydrochloride, azobis(isobutylamidine) hydrochloride, sodium 2,2'-azobisisobutyronitrile sulfonate, ferrous sulfate or hydrogen peroxide.

These polymerization initiators can be used singly or in combination, and in order to control the degree of polymerization of the polymerizable monomer, a chain transfer agent, a polymerization inhibitor, etc. can be further added and used.

The amount of inorganic silica transferred to washing was measured using a Henschel mixer (manufactured by Nippon Coke Kogyo Co., Ltd.), and the amount of external additive added, which is the external additive condition, the rotational speed (peripheral speed) of the tip of the spatter, and the rotational speed of the spatter. I coped by changing the time (time) that I was there. Table 1 below shows external additive conditions for the toner a. The details of the peripheral speed and time, which are the external addition conditions, are as described in JP-A-2016-38591. Further, 0.20 wt % of zinc stearate was externally added to the toner a used in this example.

6. Effect of Discharge Products on Photoreceptor When an image forming operation is performed using the image forming apparatus 100 , if the charging roller 2 is discharged, discharge products such as ozone and NOx are generated. May adhere to surfaces. The discharge products are scraped off by the cleaning blade 8 or the like in contact with the photoreceptor 1. If the amount of adhered products is larger than the amount of scraping off, the discharge products are gradually accumulated on the surface of the photoreceptor 1 by repeated image forming operations. go. In the contact charging method, the amount of discharge is smaller than that in the corona charging method using a corona charger, and the amount of discharge products generated is small. However, since the position where the discharge products are generated is the minute gap between the photoreceptor 1 and the charging roller 2, even if the amount of discharge products generated is small, the discharge products adhere to the surface of the photoreceptor 1. It's easy to do. When the discharge product adheres to the surface of the photoreceptor 1, it absorbs moisture and the electrical resistance of the surface of the photoreceptor 1 decreases. The decrease in resistance affects the potential formation on the photoreceptor 1 by the discharge by the charging roller 2, and the desired Vd and Vl cannot be formed. As a result, image formation cannot be properly performed, and image defects occur. Main image defects include white spots caused by latent image dullness in part or all of an image, outline blurring at image boundaries, and fogging due to potential deviation.

Therefore, in order to reduce the influence of the discharge products, in this embodiment, the metal soap 45c is supplied to the surface of the photoreceptor 1 to suppress the adhesion of the discharge products to the surface of the photoreceptor 1. FIG.

7. Metallic Soap Application Operation In Example 1, as described above, the developing roller 4 contacts the photosensitive member 1 to form a developing nip in the developing portion. Further, by providing a surface movement speed difference between the surface of the developing roller 4 and the surface of the photoreceptor 1 , the toner 10 rotates at the developing nip portion and the metal soap 45 c is supplied to the photoreceptor 1 . Hereinafter, the ratio of the surface moving speed of the developing roller 4 to the surface moving speed of the photoreceptor 1 is referred to as the DD peripheral speed ratio. When applying the metal soap 45c to the photoreceptor 1, image deletion tends to be improved as the DD peripheral speed ratio is increased. It can be considered that this is because the rolling of the toner 10 increases due to the increase in the DD peripheral speed ratio, and the chances of contact between the metal soap 45c and the photoreceptor 1 increase. Further, when the DD peripheral speed ratio is 100% or less, the contact area of the developing roller 4 per unit area of the photoreceptor 1 decreases. % is desirable. That is, it is desirable that the surface moving speed of the developing roller 4 is higher than the surface moving speed of the photoreceptor 1 . The DD peripheral speed ratio is an index that expresses the difference in surface moving speed between the surface of the photosensitive member 1 and the surface of the developing roller 4. For example, instead of the DD peripheral speed ratio, the surface moving speed difference (DD peripheral speed difference) may be used as an index. When changing the DD peripheral speed ratio and the DD peripheral speed difference, the rotational speed of the developing roller 4 may be changed, or the rotational speed of the photoreceptor 1 may be changed.

However, if the image forming operation is always performed with the DD circumferential speed ratio being large, the metallic soap 45c will be excessively supplied in the initial stage, and the metallic soap 45c will be depleted from the developing chamber 3a and the toner containing portion 3b. . In addition, the number of times the toner 10 is rubbed increases, degrading the toner 10 and impairing the chargeability.

Therefore, in the first embodiment, the metallic soap application operation is prepared separately from the normal image forming operation. In addition, the DD peripheral speed ratio is made larger than the image forming operation. During the metal soap coating operation, a charging voltage is applied to control the photoreceptor 1 to be the dark potential Vd, and the developing voltage is set to the same as that during the image forming operation, thereby performing so-called solid white printing.

The timing for executing the metallic soap application operation is preferably during the rotation of the photoreceptor 1 before the image forming operation or during the rotation of the photoreceptor 1 after the image forming operation. That is, it is executed during a non-image forming operation in which an image forming operation is not performed. Alternatively, it may be performed at a timing specified by the user.

Further, it is preferable that the amount of light of the pre-exposure unit 27 is made smaller during the metallic soap application operation than during the image forming operation, and it is particularly preferable to turn it off. This is because the smaller the amount of pre-exposure during the metallic soap coating operation, the better the image deletion. The following phenomenon can be considered as the cause of such a tendency. By reducing the amount of pre-exposure, the charge remaining on the surface of the photoreceptor 1 is not eliminated and residual charge remains. Therefore, the electrical adhesion force of the positive metal soap 45c, which is opposite in polarity to the normal polarity, to the photoreceptor 1 is strengthened, making it difficult for the soap to come off from the surface of the photoreceptor 1. FIG. In this state, when the metal soap 45c on the photoreceptor 1 passes through the cleaning blade 8 and the developing roller 4, the metal soap 45c is physically pushed into the photoreceptor 1 and strongly adheres to it. In other words, by setting the amount of pre-exposure to be smaller than that during the image forming operation, it is possible to increase the ability of the metal soap coating operation to hold the metal soap 45c on the photoreceptor 1, thereby firmly adhering the metal soap 45c to the photoreceptor 1. It is possible. On the other hand, if the amount of exposure of the surface of the photoreceptor 1 is increased, the electrical adhesion of the positive metal soap 45c to the photoreceptor 1 is weakened, and the surface of the photoreceptor 1 may be easily peeled off.

Further, it is desirable that the potential difference ΔVr (=Vdc−Vr) of the supply roller 5 with respect to the developing roller 4 is opposite in polarity to the polarity of the metal soap 45c. That is, the potential difference ΔVr is controlled so that the potential difference in the direction in which the electrostatic force acts on the metal soap 45c in the direction from the supply roller 5 toward the developing roller 4 is formed at the contact portion where the supply roller 5 and the developing roller 4 contact each other. It means that By setting ΔVr to have a polarity opposite to the polarity with which the metal soap 45c is charged, the metal soap 45c can be moved toward the developing roller 4 and can be suppressed from moving toward the supply roller 5. A large amount of metal soap 45c can be provided on the surface of body 1. In this embodiment, .DELTA.Vr=-50 V and the metal soap 45c is positively charged, so the metal soap 45c positively moves toward the developing roller 4 side.

8. Control Procedure of Metal Soap Application Operation Next, the control procedure of the metal soap application operation will be described with reference to the flowchart of FIG. In Example 1, the control unit 202 executes the metallic soap application operation. As an example of executing the metallic soap applying operation, a case of executing after the image forming operation will be described.

When the image forming apparatus 100 is ready for image formation and the user inputs a print signal (S1), the image forming operation is executed (S2). When the image forming operation is completed, the developing roller 4 is separated from the photosensitive member 1 to stop driving, and various voltages are turned off (S3). Thereafter, a metallic soap application operation is performed (S4).

First, a charging voltage, a developing voltage, a developing blade voltage, and a supply voltage are applied, and the driving of the developing roller 4 and the photoreceptor 1 is started, and the developing roller 4 is brought into contact with the photoreceptor 1, and the metal soap coating operation time is set. Measurement of (T) is started (S5). The metallic soap application operation is continued until a predetermined time T is reached (S6), and when the predetermined time is reached, the developing roller 4 is separated from the photoreceptor 1, and the driving of the developing roller 4 and the photoreceptor 1 is stopped. , the applied voltage is turned off (S7), and the metallic soap application operation is completed (S8). Subsequently, it is determined whether or not there is a request for continuous printing (S9), and if there is no request, the process shifts to a print end operation (S10). repeat the action. In this embodiment, the predetermined time T is set to 5 seconds. The predetermined time T is not limited to 5 seconds and can be set as appropriate.

The metallic soap application operation in S4 may be performed immediately after the image forming operation in S2 without performing the separation operation of the developing roller 4, or may be performed while various voltages are applied and driven as they are. .

9. Effect of Metallic Soap Applying Operation The effect of performing the metallic soap applying operation described in this embodiment was confirmed. Table 2 shows the DD peripheral speed ratio and voltage setting for the metallic soap application operation. As for the operation execution frequency, when the number of images formed reaches 600, the execution time of the metallic soap application operation was set to 5 seconds.

In Comparative Example 1, the metal soap application operation described in Example 1 is not performed. In Comparative Example 2, the DD peripheral speed ratio of the metallic soap application operation was set to the same DD peripheral speed ratio (140%) as in image formation, and the operation was performed for 5 seconds every 600 sheets. In Example 1, the DD peripheral speed ratio in the metallic soap application operation was set to 300%, which is larger than that in image formation, and the voltage setting was set in the same manner as in image formation.

The results of the actual effect confirmation are shown below. In order to confirm the occurrence of image smearing in Example 1, Comparative Example 1, and Comparative Example 2, 10,000 sheets of paper were continuously fed per day at a printing rate of 1%, and left in the machine for one day. compared with and without. The reason why the evaluation is made after being left for one day is that the discharge products generated on the surface of the photoreceptor 1 absorb moisture sufficiently by being left for one day, and the effect of lowering the surface resistance of the photoreceptor 1 becomes noticeable. is. A halftone image was printed on one sheet and evaluated as a sample for judging the presence or absence of image smearing. The evaluation index is as follows.

〇: Not generated No white spots or outline blurring at image boundaries due to latent image dulling in the entire image area △: Slightly generated White spots due to latent image dulling or outline blurring at image boundaries in some parts of the image ×: Occurred Occurrence of white spots due to dulling of the latent image and blurring of outlines at image boundaries in the entire area. The total number of sheets passed was 80,000 sheets. That is, the result is obtained by performing the metallic soap applying operation about 130 times in total. Table 3 shows the results.

As shown in Table 3, in Comparative Example 1, although the image quality was good up to 20,000 sheets, image deletion occurred after 40,000 sheets. Initially, the image flow is good because the metal soap 45c is supplied together with the toner 10, but as the image formation is repeated, the amount of the metal soap 45c remaining on the surface of the photoreceptor 1 becomes larger than the amount of the metal soap 45c that can be supplied. less. Therefore, it is considered that the image deletion occurred because the metal soap 45c could not be supplied in time only by the image forming operation.

In Comparative Example 2, the life was extended by 20,000 sheets compared to Comparative Example 1, but image deletion occurred after 60,000 sheets. The life was extended compared to Comparative Example 1 by the amount of the metal soap application operation. However, since the DD peripheral speed ratio during the metallic soap application operation is the same as that during the image forming operation, the metallic soap 45c cannot be sufficiently applied during the metallic soap application operation, and the effect of the metallic soap application operation is exhibited. Therefore, it is considered that the image deletion occurred.

In contrast, in Example 1, the image deletion was good up to 80,000 sheets. This is probably because the metal soap 45c was positively supplied to the surface of the photoreceptor 1 by the effect of increasing the DD peripheral speed ratio in the metal soap application operation, thereby exhibiting the effect of suppressing the image deletion.

The toner 10 to which the metal soap 45c is externally added is effective for preventing image smearing, but as the image formation is repeated, the supply of the metal soap 45c becomes insufficient and image smearing cannot be sufficiently suppressed. However, in the configuration of this embodiment, the toner 10 contains the metallic soap 45c and the following control is performed to suppress the image deletion. The control unit 202 controls the speed ratio between the surface moving speed of the photoreceptor 1 and the surface moving speed of the developing roller 4 to transfer the toner 10 from the image forming operation and the developing roller 4 to the surface of the photoreceptor 1 . and a metal soap applying operation of applying the metal soap 45c to the . The speed ratio between the surface moving speed of the photoreceptor 1 and the surface moving speed of the developing roller 4 in the metallic soap application operation is controlled to be greater than the speed ratio in the image forming operation. As a result, even when the metal soap 45c is insufficient, the supply of the metal soap 45c to the photoreceptor 1 can be supplemented, and image deletion can be suppressed for a long period of time.

In this embodiment, the metal soap 45c is externally added to the toner 10 and supplied from the developing roller 4 to the surface of the photoreceptor 1. It is not limited to the part 3b. A coating unit for supplying the metal soap 45c may be separately arranged on the photoreceptor 1 in addition to the developing unit 3 .

In the configuration of the image forming apparatus 100 applied in this embodiment, the same reference numerals are given to the same members as in the first embodiment, and the description thereof will be omitted.

In Example 2, during the metallic soap coating operation, the DD peripheral speed ratio is made larger than that during the image forming operation as in Example 1, and the back contrast Vback, which is the potential difference between the dark area potential Vd and the development voltage, is set to the normal value. Make it larger than when forming an image. Metallic soap 45c charged to the opposite polarity of toner 10 electrically adheres to the surface of photoreceptor 1 as the magnitude of Vback increases. This is because it is possible to In Example 1, Vback is set to 200 V during normal image formation and during metallic soap application, whereas in Example 2, it is set at 300 V during metallic soap application. Specifically, the developing voltage is set from -300V to -200V. Alternatively, in order to set the dark potential Vd from -500V to -600V, -1100V, which is -100V added to the charging voltage, may be applied to the charging roller 2 .

However, setting Vback to a large value in order to transfer the metal soap 45c onto the photoreceptor 1 also causes a problem. If Vback is too large, the toner 10 charged to the opposite polarity to the normal polarity of the toner 10 is transferred onto the surface of the photoreceptor 1, causing fogging, resulting in wasteful toner consumption. Therefore, in this embodiment, Vback during the metal coating operation is preferably 200 V or more and 500 V or less, more preferably 300 V or more and 400 V or less. Vback during the metal coating operation is set to be equal to or higher than Vback during the image forming operation, and the difference ΔVback between Vback during the metal coating operation and the image forming operation is preferably 0 V or more and 300 V or less, more preferably 100 V or more and 200 V or more. preferable.

In Example 2, the back contrast Vback, which is the difference between the surface potential of the surface of the photoreceptor 1 charged by the charging roller 2 in the developing section and the developing voltage applied to the developing roller 4, is determined by the application operation. is larger than the imaging operation. As a result, the supply of the metal soap 45c to the photoreceptor 1 can be supplemented, and image deletion can be suppressed for a long period of time.

In Example 3, the surface of the photoreceptor 1 is roughened. When the photoreceptor 1 that has undergone an appropriate roughening treatment is used, the grooves formed on the surface of the photoreceptor 1 are filled with the metal soap 45c, and the metal soap 45c is not removed and continues to remain on the surface of the photoreceptor 1. can be done. Therefore, the effect of the metallic soap application operation is further maintained, and the metallic soap 45c can be stably applied to the surface of the photoreceptor 1 for a long period of time.

In order to achieve the effects as described above, the photoreceptor 1 that has been subjected to surface roughening treatment is used that satisfies the following conditions. The ten-point average surface roughness (Rz) of the peripheral surface of the photoreceptor 1 is 0<Rz≦0.70 (μm) (preferably 0.10≦Rz≦0.50 (μm)), and the peripheral surface The average interval (Sm) of the unevenness is 0<Sm≦70 (μm) (preferably 5≦Sm≦70 (μm)). By setting the content within the above range, the metal soap 45c can be stably maintained on the surface of the photoreceptor 1, and as a result, image deletion can be suppressed for a long period of time. Therefore, in the present embodiment, the surface of the photoreceptor 1 is roughened to form suitable unevenness, thereby maintaining the durability of the photoreceptor 1 even in a configuration with a longer life and using a simple configuration. , the image deletion is suppressed.

1. Roughening Treatment of Photoreceptor The photoreceptor 1 of the present embodiment is subjected to a roughening treatment for forming minute irregularities on the surface in order to maintain the effect of the metal soap 45c. According to Japanese Patent No. 4027407, a groove extending in the circumferential direction of the peripheral surface of the photosensitive member 1 and having a width of 0.5 μm or more and 40 μm or less is formed on the peripheral surface of the photosensitive member 1 in the longitudinal direction (generatrix direction, the photoconductor 1). It is formed so that it may line up in multiple numbers in the rotation axis direction).

FIG. 6 shows an example of the state of the grooves 1b formed on the peripheral surface 1a of the photoreceptor 1. As shown in FIG. As shown in FIG. 6, each groove 1b is an annular groove extending in the circumferential direction on the peripheral surface 1a of the photoreceptor 1, and formed so as to be spaced apart from each other in the generatrix direction of the peripheral surface 1a. It is In other words, the peripheral surface 1a has a configuration in which flat portions 1c in which no grooves 1b are formed and grooves 1b are alternately formed in the generatrix direction. The area in which the groove 1b is formed on the peripheral surface 1a should include at least the area where the cleaning blade 8 contacts, and does not necessarily need to be formed over the entire length of the peripheral surface 1a.

In addition, as described in the above publication, the groove 1b is not limited to the structure formed so as to extend in the same direction as the circumferential direction as shown in FIG. For example, the groove 1b may be formed at an angle of 10° with respect to the circumferential direction. Alternatively, the grooves 1b may be formed at an angle of ±30° with respect to the circumferential direction, and the grooves 1b with different angles may cross each other. In the present embodiment, the term "substantially circumferential direction" includes both a complete circumferential direction and a substantially circumferential direction. is the direction of less than

Next, a polishing method for polishing the surface of the photoreceptor 1 will be described. FIG. 7 is a schematic diagram of a polishing device for polishing the surface of the photoreceptor 1. As shown in FIG. The polishing sheet 40 is wound in the direction of the arrow by a winding mechanism (not shown). Photoreceptor 1 rotates in the direction of the arrow. Backup roller 41 rotates in the direction of the arrow. As for the polishing conditions, a polishing sheet manufactured by Riken Corundum Co., Ltd. (trade name: GC#3000, base layer sheet thickness: 75 μm) was used as the polishing sheet 40 . A urethane roller (outer diameter: 50 mm) having a hardness of 20° is used as the backup roller 41, and the amount of penetration is 2.5 mm, and the sheet feed rate is 200 to 400 mm/s. were polished for 5 to 30 seconds while rotating in the same direction. The surface roughness of the photoreceptor 1 after polishing was measured under the following conditions using a surface roughness measuring instrument (trade name: SE700, SMB-9, manufactured by Kosaka Laboratory Ltd.). Measurements were taken at positions 30, 110 and 185 mm from the upper end of the coating in the longitudinal direction of the photoreceptor 1, rotated 120° forward, and then measured at positions 30, 110 and 185 mm from the upper end of the coating in the same manner. Further, after rotating 120° forward, measurements were taken in the same manner, and a total of 9 points were measured. Measurement conditions were as follows: measurement length: 2.5 mm, cutoff value: 0.8 mm, feed rate: 0.1 mm/s, filter characteristics: 2CR, leveling: straight line (whole area).

Table 4 shows Rz and Sm of photoreceptor 1 used in this embodiment. Photoreceptors a to f in Table 4 were produced by changing the polishing time under the roughening treatment conditions described above. The photoreceptor g is the photoreceptor 1 used in Examples 1 and 2, which is not roughened.

The ten-point average surface roughness (Rz) and the average spacing (Sm) of the unevenness of the peripheral surface of the photoreceptor 1 were determined based on the JIS standard (JIS B 0601) using a surface roughness measuring instrument manufactured by Kosaka Laboratory Co., Ltd. Using a surfcoder SE3500, measurements were made under the following conditions.
Detector: R2 μm
0.7 mN diamond stylus Filter: 2CR
Cutoff value: 0.8mm
Measurement length: 2.5mm
Feeding speed: 0.1mm

In this embodiment, 12 points in total, 4 points in the circumferential direction of each of the 3 points in the generatrix direction of the photosensitive member 1, are used as measurement points. As shown in FIG. 6, the average interval (Sm) of the unevenness of the peripheral surface of the photoreceptor 1 is the interval in the generatrix direction (longitudinal direction) of the plurality of grooves 1b arranged in the generatrix direction of the peripheral surface 1a, or the flat portion can be defined as the spacing in the generatrix direction (longitudinal direction) of 1c.

2. Effect of Application of Metallic Soap on Surface-roughened Photoreceptor Using the photoreceptor 1 described in this embodiment, the effect of performing the application of metal soap was confirmed. The DD peripheral speed ratio and voltage setting for the metallic soap application operation are as described in Example 2. In Example 3, photoreceptors a to d in Table 4 were used as photoreceptor 1. In Comparative Example 3, photoreceptor e was used. In Comparative Example 4, photoreceptor f was used.

The results of the actual effect confirmation are shown below. In order to confirm the occurrence of image smearing in Example 3, Comparative Example 3, and Comparative Example 4, 10,000 sheets of paper were continuously fed per day at a printing rate of 1%, and left in the machine for a day. compared. A halftone image was printed on one sheet and evaluated as a sample for judging the presence or absence of image smearing. Other conditions were the same as in Example 2. The evaluation index is as follows.
〇: Not generated No white spots or outline blurring at image boundaries due to latent image dulling in the entire image area △: Slightly generated White spots due to latent image dulling or outline blurring at image boundaries in some parts of the image ×: Occurred Occurrence of white spots and outline blurring at image boundaries due to latent image dullness in the entire area

The environment for paper feeding and sample output was 30° C./80% RH. The total number of sheets passed was up to 120,000 sheets. Table 5 shows the results.

As shown in Table 5, when the photosensitive members a to d of Example 3 were used, no image deletion occurred after 120,000 sheets. This is because the metal soap 45c can be held on the surface of the photoreceptor 1 by forming appropriate grooves on the surface of the photoreceptor 1 at appropriate intervals.

The uneven shape of the surface of the photoreceptor 1 subjected to the roughening treatment in this embodiment is such that the range of the ten-point average surface roughness (Rz) of the peripheral surface is 0<Rz≦0.70 (μm), and The average interval of unevenness on the peripheral surface is 0<Sm≦70.0 (μm). By using the photoreceptor 1 under the above conditions, the effect of the metallic soap application operation is maintained.

Photoreceptor e of Comparative Example 3 has Rz=0.75 (μm), and grooves are deeply formed on the surface of photoreceptor 1. Therefore, a large amount of metal soap 45c is required until the grooves are sufficiently filled. It is thought that it was a condition that could not fully demonstrate Since the results were good with Rz=0.68 (μm) of the photoreceptor c of Example 3, it was found that the effect of the roughening treatment is enhanced when Rz is less than 0.70 (μm). . Furthermore, it has been found that the metal soap 45c having a preferable average particle size of 0.15 μm to 2.0 μm has a shape that can be easily applied to the grooves having the above depth.

Further, since the photoreceptor f of Comparative Example 4 has Sm=78.5 (μm), the intervals between the grooves are wide, and there are many portions where the grooves do not exist. It is thought that there has been some negative impact. Since the results were good when Sm=67.3 (μm) of the photoreceptor d of Example 3, it was found that when the Sm was less than 70.0 (μm), the effect of the roughening treatment was enhanced. .

From the above results, the surface shape of the photoreceptor 1 subjected to the surface roughening treatment of Example 3 was determined to have a ten-point average surface roughness (Rz) of the peripheral surface in the range of 0<Rz≦0.70 (μm). , the average interval of unevenness on the peripheral surface is 0<Sm≦70.0 (μm). Furthermore, preferably, the ten-point average surface roughness (Rz) of the peripheral surface is 0.10 ≤ Rz ≤ 0.50 (μm), and the average interval (Sm) of the unevenness of the peripheral surface is 5 ≤ Sm ≤ 70 ( μm). By setting 0.10≦Rz≦0.50 (μm) and 5≦Sm≦70 (μm), the unevenness works effectively, and the metal soap 45c is more likely to stay on the surface of the photoreceptor 1 . As a result, the metal soap 45c can be stably maintained on the surface of the photoreceptor 1. As shown in FIG. Therefore, if the photoreceptor 1 is roughened as in the configuration of the third embodiment, the durability of the photoreceptor can be maintained even in a configuration with a longer life, and the occurrence of image deletion can be suppressed with a simple configuration. became possible.

In Examples 1, 2, and 3, the case of using the toner to which the inorganic silicon fine particles as shown in FIG. 4 are externally added has been described. In Example 4, a case where the toner is changed and an organosilicon polymer toner having a surface layer containing an organosilicon polymer is used will be described.

When the organosilicon polymer toner is used as in this embodiment, the organosilicon polymer is less likely to come off from the toner even by mechanical rubbing, and only the metallic soap 45c is efficiently supplied to the photosensitive member 1 by the metallic soap coating operation. can do Therefore, the effect of the metallic soap application operation is further maintained, and the metallic soap 45c can be stably applied to the surface of the photoreceptor 1 for a long period of time. In addition, since the organic silicon polymer in the surface layer can be used to control the charge of the toner and the physical properties of the toner, which are the inherent effects of adding inorganic silica externally, the image is hardly affected.

Therefore, in Example 4, by using an organosilicon polymer toner having a surface layer containing an organosilicon polymer, the durability of the photoreceptor 1 can be maintained even in a long-life configuration, and with a simple configuration, It is characterized by being configured to suppress the occurrence of image deletion. Note that descriptions of portions that overlap with the first, second, and third embodiments are omitted.

1. Toner Containing Organosilicon Polymer in Surface Layer In Example 4, the toner particles as shown in FIG. 8 and the organic A toner with a silicon polymer is used.
R-SiO3/2 (1)
(R represents a hydrocarbon group having 1 to 6 carbon atoms.)

The surface of the toner particles is coated with an organosilicon polymer having a structure represented by formula (1) and has a surface layer which is the outermost layer of the toner particles. The surface layer is very hard compared to conventional toner particles. Therefore, from the viewpoint of fixability, a portion where the surface layer is not formed may be provided on a part of the surface of the toner particles. The ratio of the number of splitting axes in which the thickness of the surface layer containing the organosilicon polymer is 2.5 nm or less (hereinafter also referred to as the ratio of the thickness of the surface layer of 2.5 nm or less) is preferably 20.0% or less. . This condition approximates that at least 80.0% or more of the surface of the toner particles is composed of a surface layer containing an organosilicon polymer of 2.5 nm or more. That is, when this condition is satisfied, the surface layer containing the organosilicon polymer sufficiently covers the surface of the toner particles. More preferably, the proportion of the surface layer having a thickness of 2.5 nm or less is 10.0% or less. Measurement can be defined by cross-sectional observation using a transmission electron microscope (TEM). Details will be described later.

Next, the organosilicon polymer having the structure represented by formula (1) will be described. In the organosilicon polymer having the structure represented by formula (1), one of the four valences of Si atoms is bonded to R and the remaining three are bonded to O atoms. The O atom forms a state in which both of its two valences are bonded to Si, that is, a siloxane bond (Si--O--Si). Considering Si atoms and O atoms as an organosilicon polymer, since two Si atoms have three O atoms, it is expressed as -SiO3/2. Furthermore, in the chart obtained by 29Si-NMR measurement of the tetrahydrofuran (THF)-insoluble portion of the toner particles, the ratio of the peak area attributed to the structure of formula (1) to the total peak area of the organosilicon polymer is 20% or more. is preferred. Although the detailed measurement method will be described later, this approximates that the organosilicon polymer contained in the toner particles has a partial structure represented by R--SiO3/2 in an amount of 20% or more.

As described above, the —SiO3/2 structure means that three of the four valences of Si atoms are bonded to oxygen atoms, and these oxygen atoms are bonded to other Si atoms. If one of the oxygens is a silanol group, the structure of the organosilicon polymer is represented by R--SiO2/2-OH. Furthermore, if two oxygens are silanol groups, the structure will be R--SiO1/2(--OH)2. Comparing these structures, more oxygen atoms forming a bridge structure with Si atoms is closer to the silica structure represented by SiO2. Therefore, the more the -SiO3/2 skeleton, the lower the surface free energy of the surface of the toner particles. In addition, due to the durability due to the structure represented by formula (1) and the hydrophobicity and chargeability of R in formula (1), a low molecular weight (= Mw: 1000 or less) that is present inside the surface layer and is easy to seep out ) and resins with a low glass transition temperature (Tg: 40° C. or lower) are prevented from bleeding. Bleeding of the release agent can also be suppressed in some cases.

The ratio of the peak area of the structure represented by formula (1) depends on the type and amount of the organosilicon compound used to form the organosilicon polymer, and the reaction temperature of hydrolysis, addition polymerization, and condensation polymerization during the formation of the organosilicon polymer. , reaction time, reaction solvent and pH. In the structure represented by formula (1), R is a hydrocarbon group having 1 to 6 carbon atoms. This tends to stabilize the charge amount. An aliphatic hydrocarbon group having 1 to 6 carbon atoms or a phenyl group, which is particularly excellent in environmental stability, is preferable. In the embodiment of the present invention, R is more preferably an aliphatic hydrocarbon group having 1 or more and 3 or less carbon atoms in order to further improve chargeability and antifogging. If the chargeability is good, the transferability is good and the amount of residual toner after transfer is small, so that the contamination of the photoreceptor 1 and the charging roller 2 is improved. Preferred examples of the aliphatic hydrocarbon group having 1 to 3 carbon atoms include methyl group, ethyl group, propyl group and vinyl group. From the viewpoint of environmental stability and storage stability, R is more preferably a methyl group. A sol-gel method is preferable as an example of the production of the organosilicon polymer. The sol-gel method is a method of hydrolyzing and condensation-polymerizing a liquid raw material as a starting raw material to form a sol state and then gelling, and is used in a method of synthesizing glasses, ceramics, organic-inorganic hybrids, and nanocomposites. By using this production method, functional materials in various shapes such as surface layers, fibers, bulk bodies, and fine particles can be produced from the liquid phase at a low temperature. Specifically, the organosilicon polymer present on the surface layer of the toner particles is preferably produced by hydrolysis and polycondensation of a silicon compound represented by alkoxysilane. By providing the surface layer containing the organosilicon polymer on the toner particles, the environmental stability is improved, and the performance of the toner is less likely to deteriorate during long-term use, making it possible to obtain a toner with excellent storage stability. .

Furthermore, the sol-gel method starts from a liquid and forms a material by gelling the liquid, so various microstructures and shapes can be produced. In particular, when the toner particles are produced in an aqueous medium, the particles are easily precipitated on the surface of the toner particles due to the hydrophilicity of the hydrophilic group such as the silanol group of the organosilicon compound. The fine structure and shape can be adjusted by the reaction temperature, reaction time, reaction solvent, pH, the type and amount of the organometallic compound, and the like. The organosilicon polymer is preferably a condensation polymer of an organosilicon compound having a structure represented by formula (Z) below.

（式（Ｚ）中、Ｒ１は、炭素数１以上６以下の炭化水素基を表し、Ｒ２、Ｒ３及びＲ４は、それぞれ独立して、ハロゲン原子、ヒドロキシ基、アセトキシ基、又は、アルコキシ基を表す。）

(In the formula (Z), R1 represents a hydrocarbon group having 1 to 6 carbon atoms, and R2, R3 and R4 each independently represents a halogen atom, a hydroxy group, an acetoxy group, or an alkoxy group. .)

Hydrophobicity can be improved by the hydrocarbon group (preferably alkyl group) of R1, and toner particles with excellent environmental stability can be obtained. In addition, an aryl group that is an aromatic hydrocarbon group such as a phenyl group can also be used as the hydrocarbon group. When the hydrophobicity of R1 is large, the charge amount tends to increase in various environments. Therefore, in view of environmental stability, R1 is preferably an aliphatic hydrocarbon group having 1 to 3 carbon atoms. A methyl group is more preferred. That is, it is preferable that the number of carbon atoms directly bonded to silicon atoms in the organosilicon polymer is 1 or more and 3 or less. R2, R3 and R4 are each independently a halogen atom, a hydroxy group, an acetoxy group or an alkoxy group (hereinafter also referred to as a reactive group). These reactive groups form a crosslinked structure through hydrolysis, addition polymerization, and condensation polymerization, and a toner excellent in member contamination resistance and development durability can be obtained. From the viewpoint of moderate hydrolyzability at room temperature and deposition and coating properties on the surface of toner particles, an alkoxy group having 1 to 3 carbon atoms is preferable, and a methoxy group or an ethoxy group is more preferable. preferable. Also, the hydrolysis, addition polymerization and condensation polymerization of R2, R3 and R4 can be controlled by reaction temperature, reaction time, reaction solvent and pH.

In order to obtain the organosilicon polymer used in the embodiment of the present invention, an organosilicon compound ( hereinafter also referred to as trifunctional silane) may be used singly or in combination. Examples of the above formula (Z) include the following.

Methyltrimethoxysilane, Methyltriethoxysilane, Methyldiethoxymethoxysilane, Methylethoxydimethoxysilane, Methyltrichlorosilane, Methylmethoxydichlorosilane, Methylethoxydichlorosilane, Methyldimethoxychlorosilane, Methylmethoxyethoxychlorosilane, Methyldiethoxychlorosilane, Methyl triacetoxysilane, methyldiacetoxymethoxysilane, methyldiacetoxyethoxysilane, methylacetoxydimethoxysilane, methylacetoxymethoxyethoxysilane, methylacetoxydiethoxysilane, methyltrihydroxysilane, methylmethoxydihydroxysilane, methylethoxydihydroxysilane, methyldimethoxysilane trifunctional methylsilanes such as hydroxysilane, methylethoxymethoxyhydroxysilane, methyldiethoxyhydroxysilane;

ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane, ethyltriacetoxysilane, ethyltrihydroxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, propyltriacetoxysilane, propyltrihydroxysilane, butyltri Trifunctional such as methoxysilane, butyltriethoxysilane, butyltrichlorosilane, butyltriacetoxysilane, butyltrihydroxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexyltrichlorosilane, hexyltriacetoxysilane, hexyltrihydroxysilane sex silane.

Trifunctional phenylsilanes such as phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane, phenyltrihydroxysilane.

In addition to the organosilicon compound having the structure represented by the formula (Z), an organosilicon polymer obtained by combining the following may be used to the extent that the effects of this example are not impaired. Organosilicon compounds with four reactive groups in one molecule (tetrafunctional silane), organosilicon compounds with two reactive groups in one molecule (bifunctional silane), or organosilicon compounds with one reactive group (difunctional silane) monofunctional silane). For example:

dimethyldiethoxysilane, tetraethoxysilane, hexamethyldisilazane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriemethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-amino ethyl)aminopropyltriethoxysilane, vinyltriisocyanatesilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyldiethoxymethoxysilane, vinylethoxydimethoxysilane, vinylethoxydihydroxysilane, vinyldimethoxyhydroxysilane, vinylethoxymethoxyhydroxysilane, Trifunctional vinylsilanes, such as vinyldiethoxyhydroxysilane.

Furthermore, the content of the organosilicon polymer in the toner particles is preferably 0.5% by mass or more and 10.5% by mass or less. When the content of the organosilicon polymer is 0.5% by mass or more, the surface free energy of the surface layer can be further reduced, the fluidity can be improved, and the contamination of the member and the occurrence of fogging can be suppressed. . When it is 10.5% by mass or less, charge-up can be made difficult to occur. The content of the organosilicon polymer is controlled by the type and amount of the organosilicon compound used to form the organosilicon polymer, the method of producing toner particles during the formation of the organosilicon polymer, reaction temperature, reaction time, reaction solvent and pH. can be done. It is preferable that the surface layer containing the organosilicon polymer and the toner core particles are in contact without any gap. As a result, the occurrence of bleeding caused by the resin component, release agent, etc. inside the toner particles is suppressed from the surface layer of the toner particles, and a toner excellent in storage stability, environmental stability and development durability can be obtained. In addition to the organosilicon polymer described above, the surface layer may contain resins such as styrene-acrylic copolymer resins, polyester resins and urethane resins, and various additives.

2. Method for Confirming Partial Structure by NMR Measurement Next, a method for confirming the partial structure of toner particles by NMR measurement will be described. The tetrahydrofuran (THF) insolubles of the toner particles described above were prepared as follows. 10.0 g of toner particles are weighed, placed in a thimble (No. 86R manufactured by Toyo Roshi Kaisha Ltd.), and placed in a Soxhlet extractor. Extraction was performed using 200 mL of THF as a solvent for 20 hours, and the filtered matter in the thimble was vacuum-dried at 40° C. for several hours. When the surface of the toner particles is treated with an external additive or the like, the external additive is removed by the following method to obtain toner particles.

160 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) is added to 100 mL of ion-exchanged water and dissolved in a hot water bath to prepare a concentrated sucrose solution. In a centrifugation tube (capacity: 50 mL), 31 g of the concentrated sucrose solution and Contaminon N (a pH 7 neutral detergent for cleaning precision measuring instruments consisting of a nonionic surfactant, an anionic surfactant, and an organic builder) were added. 6 mL of a mass % aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) is added to prepare a dispersion. 1.0 g of toner is added to this dispersion, and clumps of toner are loosened with a spatula or the like.

The centrifuge tube is shaken on a shaker at 350 spm (strokes per min) for 20 minutes. After shaking, the solution is transferred to a swing rotor glass tube (capacity 50 mL) and separated in a centrifuge (manufactured by H-9R Kokusan Co., Ltd.) at 3500 rpm for 30 minutes. This operation separates the toner particles from the detached external additive. It is visually confirmed that the toner and the aqueous solution are sufficiently separated, and the separated toner on the uppermost layer is collected with a spatula or the like. After filtering the collected toner with a vacuum filter, it is dried with a dryer for 1 hour or longer to obtain toner particles. This operation is carried out multiple times to ensure the required amount.

The following method is used to confirm the partial structure represented by formula (1) in the organosilicon polymer contained in the toner particles. The hydrocarbon group represented by R in formula (1) was confirmed by 13C-NMR.

<< ¹³ C-NMR (solid) measurement conditions >>
Device: JNM-ECX500II manufactured by JEOLRESONANCE
Sample tube: 3.2 mmφ
Sample: 150 mg of tetrahydrofuran-insoluble matter of toner particles for NMR measurement
Measurement temperature: Room temperature Pulse mode: CP/MAS
Measurement nuclear frequency: 123.25 MHz ( ¹³ C)
Reference substance: adamantane (external standard: 29.5 ppm)
Sample rotation speed: 20 kHz
Contact time: 2ms
Delay time: 2s
Accumulated times: 1024 times

By the above method, a methyl group (Si--CH ₃ ), an ethyl group (Si--C ₂ H ₅ ), a propyl group (Si--C ₃ H ₇ ), a butyl group (Si--C ₄ H ₉ ), pentyl group (Si—C ₅ H ₁₁ ), hexyl group (Si—C ₆ H ₁₃ ) or phenyl group (Si—C ₆ H ₅ —), etc. The hydrocarbon group represented by R was confirmed. Next, a method for calculating the ratio of the peak area attributed to the structure of formula (1) in the organosilicon polymer contained in the toner particles will be described.

²⁹ Si-NMR (solid) measurement of the THF-insoluble portion of the toner particles is performed under the following measurement conditions.

<< ²⁹ Si-NMR (solid) measurement conditions >>
Device: JNM-ECX500II manufactured by JEOLRESONANCE
Sample tube: 3.2 mmφ
Sample: 150 mg of tetrahydrofuran-insoluble matter of toner particles for NMR measurement
Measurement temperature: Room temperature Pulse mode: CP/MAS
Measured nuclear frequency: 97.38 MHz ( ²⁹ Si)
Reference substance: DSS (external standard: 1.534 ppm)
Sample rotation speed: 10 kHz
Contact time: 10ms
Delay time: 2s
Accumulated times: 2000 to 8000 times

After the above measurement, a plurality of silane components having different substituents and bonding groups in the tetrahydrofuran-insoluble portion of the toner particles were peak-separated into the following X1 structure, X2 structure, X3 structure, and X4 structure by curve fitting. Calculate area.
X1 structure: (Ri) (Rj) (Rk) SiO _1/2 Formula (2)
X2 structure: (Rg)(Rh)Si(O _1/2 ) ₂ Formula (3)
X3 structure: RmSi(O _1/2 ) ₃ Formula (4)
X4 structure: Si(O _1/2 ) ₄ Formula (5)

（式（２）、（３）及び（４）中のＲｉ、Ｒｊ、Ｒｋ、Ｒｇ、Ｒｈ、Ｒｍはケイ素に結合している、炭素数１～６の炭化水素基などの有機基、ハロゲン原子、ヒドロキシ基、アセトキシ基又はアルコキシ基を示す。）

(Ri, Rj, Rk, Rg, Rh, and Rm in formulas (2), (3), and (4) are bonded to silicon, organic groups such as hydrocarbon groups having 1 to 6 carbon atoms, halogen atoms , indicates a hydroxy group, an acetoxy group, or an alkoxy group.)

In the embodiment of the present invention, in the chart obtained by ²⁹ Si-NMR measurement of the THF-insoluble portion of the toner particles, the ratio of the peak area attributed to the structure of formula (1) to the total peak area of the organosilicon polymer It is preferable that the ratio is 20% or more.

If it is necessary to confirm the structure represented by the above formula (1) in more detail, it may be identified by the measurement results of ¹ H-NMR together with the measurement results of ¹³ C-NMR and ²⁹ Si-NMR.

3. Method for Measuring Surface Layer Thickness by Cross-Sectional Observation of Toner Particle Next, the percentage of the surface layer containing the organosilicon polymer having a thickness of 2.5 nm or less, which is measured by cross-sectional observation of the toner particles using a transmission electron microscope (TEM). will be explained. In this embodiment, observation of the cross section of the toner particles is performed by the following method.

After sufficiently dispersing the toner particles in the room temperature curable epoxy resin, the resin is cured in an atmosphere of 40° C. for 2 days. A flaky sample is cut from the obtained cured product using a microtome equipped with diamond teeth. This sample is magnified by a magnification of 10,000 to 100,000 times with a transmission electron microscope (JEM-2800 manufactured by JEOL) (TEM) to observe the cross section of the toner particles. This can be confirmed by utilizing the difference in atomic weight between the binder resin and the surface layer material, and by utilizing the fact that the higher the atomic weight, the brighter the contrast. Ruthenium tetroxide staining and osmium tetroxide staining are used to provide contrast between materials. For the particles used for the measurement, the circle-equivalent diameter Dtem is determined from the cross section of the toner particles obtained from the above-mentioned TEM micrograph, and the value is included in the range of ±10% of the weight-average particle diameter D4 of the toner particles. do.

As described above, using JEM-2800 manufactured by JEOL, a dark field image of the cross section of the toner particles is obtained at an accelerating voltage of 200 kV. Next, using an EELS detector GIFQuantam manufactured by Gatan, a mapping image is acquired by the Three Window method to confirm the surface layer.

Next, for one toner particle whose circle-equivalent diameter Dtem is within ±10% of the weight-average particle diameter D4 of the toner particle, As shown in FIG. 8, the cross section of the toner particles is evenly divided into 16 with the intersection point of the axis L90 as the center. Next, let An (n=1 to 32) be the division axis extending from the center to the surface layer of the toner particle, RAn be the length of the division axis, and FRAn be the thickness of the surface layer. Then, the ratio of the number of dividing axes having a surface layer containing the organosilicon polymer having a thickness of 2.5 nm or less among the 32 dividing axes is obtained. For averaging, 10 toner particles are measured and the average per toner particle is calculated.

The circle equivalent diameter (Dtem) obtained from the cross section of the toner particles obtained from the TEM photograph is obtained by the following method. First, for one toner particle, the equivalent circle diameter Dtem obtained from the cross section of the toner particle obtained from the TEM photograph is obtained according to the following formula.

[Circle equivalent diameter (Dtem) obtained from the cross section of toner particles obtained from a TEM photograph]=(RA1+RA2+RA3+RA4+RA5+RA6+RA7+RA8+RA9+RA10+RA11+RA12+RA13+RA14+RA15+RA16+RA17+RA18+RA19+RA20+RA21+RA22+RA23+RA24+RA25+RA26+RA 27+RA28+RA29+RA30+RA31+RA32)/16
Equivalent circle diameters of 10 toner particles are obtained, and the average value per particle is calculated as the equivalent circle diameter (Dtem) obtained from the cross section of the toner particles.

The proportion of the surface layer containing the organosilicon polymer having a thickness of 2.5 nm or less is expressed by the following formula.
[Percentage of surface layer containing organosilicon polymer having thickness (FRAn) of 2.5 nm or less]=[{Number of splitting axes having surface layer containing organosilicon polymer having thickness (FRAn) of 2.5 nm or less] }/32]×100
This calculation was performed for 10 toner particles, and the average value of the percentage of the 10 toner particles having a surface layer thickness (FRAn) of 2.5 nm or less was obtained. A ratio of 5 nm or less was used.

4. Toner Manufacturing Method Hereinafter, the toner used in Example 4 will be specifically described, but the toner is not limited to these examples. All "parts" of each material in Examples and Comparative Examples are based on mass unless otherwise specified.

First, the preparation process of the aqueous medium 1 will be described. To 1000.0 parts of ion-exchanged water in a reaction vessel, 14.0 parts of sodium phosphate (12 hydrate, manufactured by Rasa Kogyo Co., Ltd.) was added, and the mixture was kept at 65° C. for 1.0 hour while purging with nitrogen. T. K. Using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), while stirring at 12000 rpm, a calcium chloride aqueous solution obtained by dissolving 9.2 parts of calcium chloride (dihydrate) in 10.0 parts of ion-exchanged water is mixed together. to prepare an aqueous medium containing a dispersion stabilizer. Furthermore, 10% by mass hydrochloric acid was added to the aqueous medium to adjust the pH to 5.0, and an aqueous medium 1 was obtained.

Next, the hydrolysis step of the organosilicon compound for the surface layer will be described. 60.0 parts of ion-exchanged water was weighed into a reactor equipped with a stirrer and a thermometer, and the pH was adjusted to 3.0 using 10% by mass hydrochloric acid. This was heated with stirring to bring the temperature to 70°C. Thereafter, 40.0 parts of methyltriethoxysilane, which is an organosilicon compound for the surface layer, was added and hydrolyzed by stirring for 2 hours or more. The end point of the hydrolysis was visually confirmed by confirming that the oil and water did not separate and became one layer, and then cooled to obtain a hydrolyzate of the organosilicon compound for the surface layer.
In the case of forming the surface layer containing the organosilicon polymer as in this embodiment, in the case of forming the toner particles in the aqueous medium, the organosilicon polymer is formed as described above while performing the polymerization process described later in the aqueous medium. A surface layer can be formed by adding a hydrolyzate of the compound. A surface layer may be formed by adding a hydrolyzate of an organosilicon compound to a dispersion of toner particles after polymerization as a dispersion of core particles. In the case of a kneading pulverization method other than an aqueous medium, the obtained toner particles are dispersed in an aqueous medium and used as a core particle dispersion, and the hydrolyzate of the organosilicon compound is added as described above to form a surface layer. can be formed.

Next, the preparation process of the polymerizable monomer composition will be described.
- Styrene 60.0 parts - C.I. I. Pigment Blue 15:3 6.5 parts The above materials are put into an attritor (manufactured by Mitsui Miike Kakoki Co., Ltd.), and further dispersed using zirconia particles with a diameter of 1.7 mm at 220 rpm for 5.0 hours to disperse the pigment. A liquid was prepared. The following materials were added to the pigment dispersion.
・Styrene 20.0 parts ・n-butyl acrylate 20.0 parts ・Crosslinking agent (divinylbenzene) 0.3 parts ・Saturated polyester resin 5.0 parts (propylene oxide-modified bisphenol A (2 mol adduct) and terephthalic acid (molar ratio 10:12), glass transition temperature Tg = 68 ° C., weight average molecular weight Mw = 10000, molecular weight distribution Mw / Mn = 5.12)
- 7.0 parts of Fischer-Tropsch wax (melting point 78°C). K. A homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) was used to uniformly dissolve and disperse at 500 rpm to prepare a polymerizable monomer composition.

Next, the granulation process will be described. The temperature of the aqueous medium 1 is set at 70°C, T.E. K. While maintaining the rotation speed of the homomixer at 12000 rpm, the polymerizable monomer composition was charged into the aqueous medium 1, and 9.0 parts of t-butyl peroxypivalate as a polymerization initiator was added. The mixture was granulated for 10 minutes while maintaining 12000 rpm with a stirring device.

Next, the polymerization process will be explained. After the granulation step, the agitator was changed to a propeller agitating blade, and while stirring at 150 rpm, the mixture was maintained at 70°C and polymerized for 5.0 hours. core particles were obtained. When the temperature of the slurry was cooled to 55° C. and the pH was measured, it was pH=5.0. While stirring was continued at 55° C., 20.0 parts of the hydrolyzate of the organosilicon compound for the surface layer was added to start forming the surface layer of the toner. After holding for 30 minutes as it is, the slurry was adjusted to pH=9.0 for completion of condensation using an aqueous sodium hydroxide solution and held for an additional 300 minutes to form a surface layer.

Finally, the washing and drying steps will be explained. After completion of the polymerization process, the slurry of toner particles is cooled, and hydrochloric acid is added to the slurry of toner particles to adjust the pH to 1.5 or less, and the mixture is left with stirring for 1 hour, followed by solid-liquid separation with a pressurized filter to form a toner cake. got This was reslurried with ion-exchanged water to form a dispersion again, and then subjected to solid-liquid separation with the aforementioned filter. After reslurry and solid-liquid separation were repeated until the electrical conductivity of the filtrate became 5.0 μS/cm or less, solid-liquid separation was finally performed to obtain a toner cake. The resulting toner cake was dried with a flash jet dryer (manufactured by Seishin Enterprise Co., Ltd.). The drying conditions were a blowing temperature of 90.degree. C., a dryer outlet temperature of 40.degree.

Silicon mapping is performed in cross-sectional TEM observation of toner particles 1, and the presence of silicon atoms in the surface layer and the ratio of the number of splitting axes having a thickness of 2.5 nm or less in the surface layer of the toner particles containing the organosilicon polymer are It was confirmed to be 20.0% or less. In this example, the obtained toner particles were used as the toner of Example 4 as they were without adding inorganic silicon externally.

The fixation rate of the organosilicon polymer having the structure represented by formula (1) covering the surfaces of the toner particles is preferably 30% or more and 100% or less. This is because the increase in the area of the surface layer where the organosilicon polymer does not exist increases the adhesion force between the toner particles and changes the chargeability.

In Example 4, a toner in which the surfaces of the toner particles are coated with the organic silicon polymer is used instead of externally adding the organic silicon polymer or the inorganic silicon fine particles to the mother particles. Since the organosilicon polymer is less likely to come off from the toner (higher fixation rate) than when externally added toner is used, only the metal soap 45c can be efficiently supplied to the photoreceptor 1. It is possible to further maintain the image deletion suppressing effect.

5. Confirmation of Effect of Toner Particles Using Organosilicon Polymer In Example 4, toners b to e were produced by using the above-described toner production method so that the fixation ratio of the organosilicon polymer coating the surface of the toner particles was different. prepared. The fixation rate varies depending on the toner manufacturing conditions. In this example, toners with different fixation rates were produced by changing the conditions for adding the hydrolyzate in the polymerization step and the holding time after the addition. In addition, pH adjustment was performed with hydrochloric acid and sodium hydroxide aqueous solution. Table 6 shows the conditions for producing toners with different fixing rates. Further, in the toners b to e produced by the above method, 0.20% by mass of zinc stearate was externally added as the metal soap 45c in the same manner as in Example 1. However, with respect to Toner e, the hydrolysis step of the organosilicon compound for the surface layer was not performed. Instead, 30 parts of methyltriethoxysilane, which is an organosilicon compound for the surface layer, was added as a monomer in the process of preparing the polymerizable monomer composition. In the polymerization step, the hydrolyzate was not added after cooling to 70° C. and measuring the pH. While continuing to stir at 70° C., the slurry was adjusted to pH=9.0 for completion of condensation using an aqueous sodium hydroxide solution and held for an additional 300 minutes to form a surface layer.

The results of the actual effect confirmation are shown below. In order to confirm the occurrence of image smearing for Toner e of Comparative Example 5, Toner b, Toner c, and Toner d of Example 4, 10,000 sheets of paper were continuously fed per day at a printing rate of 1%, and left in the machine for one day. The presence or absence of occurrence of image deletion after that was compared. A halftone image was printed on one sheet and evaluated as a sample for judging the presence or absence of image smearing. The evaluation index is as follows.
〇: Not generated No white spots or outline blurring at image boundaries due to latent image dulling in the entire image area △: Slightly generated White spots due to latent image dulling or outline blurring at image boundaries in some parts of the image ×: Occurred Occurrence of white spots and outline blurring at image boundaries due to latent image dullness in the entire area

The environment for paper feeding and sample output was 30° C./80% RH. The total number of sheets passed was up to 160,000 sheets. The photoreceptor 1 was roughened as in Example 3 and satisfied the Rz and Sm conditions. Table 7 shows the examination results.

As shown in Table 7, toner b, toner c, and toner d in Example 4 using the toner in which the surface of the toner particles is coated with an organosilicon polymer are higher than the toner e in Comparative Example 5. In , no image smear occurred up to 160,000 sheets, and even better images were obtained.

If the fixation rate of the organosilicon polymer is high, the organosilicon polymer is less likely to be supplied to the grooves on the surface of the photoreceptor 1 and the metal soap 45c is more likely to be supplied to the grooves on the surface of the photoreceptor 1 . This is because the organosilicon polymer is less likely to come off from the toner, and only the metal soap 45c can be efficiently supplied to the photoreceptor 1 by the metal soap coating operation. By setting the fixing rate of the organosilicon polymer to 90% or more as in the present embodiment, it becomes possible to positively supply the metal soap 45c onto the surface of the photoreceptor 1. FIG. Therefore, the effect of the metal soap 45c for suppressing image deletion by the metal soap application operation is sustained, and the metal soap 45c can be stably applied to the surface of the photoreceptor 1 for a long period of time.

In the configuration of Example 4, by using the organosilicon polymer toner having the surface layer containing the organosilicon polymer, the effect of suppressing the image deletion of the metallic soap 45c due to the metallic soap application operation is maintained.

As a result, the metal soap 45c can be stably maintained on the surface of the photoreceptor 1, and the durability of the photoreceptor 1 can be maintained even in a configuration with a longer service life. It is possible to suppress the occurrence.

In addition, although reversal development is used in Examples 1, 2, 3, and 4, the present invention is not limited to this, and normal development may be used. In Examples 1, 2, 3, and 4, the negatively charged photoreceptor 1 was used, but the present invention is not limited to this, and a positively charged photoreceptor may be used.

Further, although a color laser printer is used as the image forming apparatus 100 in the first, second, third, and fourth embodiments, the image forming apparatus 100 having a single cartridge structure like a monochrome laser printer is used. It's okay.

Further, instead of the intermediate transfer method using the intermediate transfer belt 31, a method of directly transferring the toner image formed on the surface of the photoreceptor 1 onto the recording material S may be used.

In addition, the setting conditions used for explanation in Example 1, Example 2, Example 3, and Example 4 are examples, and are not limited thereto.

REFERENCE SIGNS LIST 1 photoreceptor 2 charging roller 3b toner container 4 developing roller 10 toner 45c metal soap 100 image forming apparatus 202 control unit

Claims (17)

In an image forming apparatus that forms a toner image on a recording material,
A rotatable image carrier, wherein the range of ten-point average surface roughness (Rz) of the surface of the image carrier is 0.10≦Rz≦0.70 (μm) in the rotation axis direction of the image carrier. ) and the range of the average interval (Sm) of the unevenness of the surface of the image carrier is 0<Sm≦70 (μm);
a charging member that charges the surface of the image carrier;
a toner containing portion containing a toner containing a metallic soap;
a developing member that forms a toner image by supplying the toner to the surface of the image carrier charged by the charging member in a developing section facing the image carrier;
a control unit that controls at least one of the rotation speed of the image carrier and the rotation speed of the developing member so that the surface moving speed of the developing member is higher than the surface moving speed of the image carrier. ,
an image forming operation for forming the toner image on a recording material; and an operation different from the image forming operation, in which the toner contained in the toner container is supplied from the developing member to the surface of the image carrier. and an application operation of applying the metallic soap to the surface of the image carrier by:
The control unit performs control so that a speed difference between a surface moving speed of the developing member and a surface moving speed of the image carrier in the coating operation is larger than the speed difference in the image forming operation. image forming apparatus. a first voltage applying unit that applies a charging voltage to the charging member;
a second voltage applying unit that applies a developing voltage to the developing member;
When the difference between the surface potential of the surface of the image carrier charged by the charging member in the developing section and the developing voltage applied to the developing member by the second voltage applying section is defined as back contrast 2. The image forming apparatus according to claim 1 , wherein said control unit performs control such that said back contrast in said coating operation is greater than that in said image forming operation. a toner supply member that contacts the developing member to form a contact portion and supplies the toner at the contact portion;
a third voltage applying unit that applies a toner supply voltage to the toner supply member;
The control unit applies the second voltage such that, in the application operation, a potential difference is formed at the contact portion in a direction that an electrostatic force acts on the metallic soap in a direction from the toner supply member toward the developing member. 3. The image forming apparatus according to claim 2 , wherein the third voltage application section and the third voltage application section are controlled. 4. The image forming apparatus according to claim 1 , wherein the developing member rotates at different surface moving speeds between the image forming operation and the coating operation. 5. The image forming apparatus according to claim 1 , wherein the image carrier rotates at different surface moving speeds between the image forming operation and the coating operation. In an image forming apparatus that forms a toner image on a recording material,
a rotatable image carrier;
a charging member that charges the surface of the image carrier;
a toner containing portion containing a toner containing a metallic soap;
a developing member that forms a toner image by supplying the toner to the surface of the image carrier charged by the charging member in a developing section facing the image carrier;
a toner supply member that contacts the developing member to form a contact portion and supplies the toner at the contact portion;
a first voltage applying unit that applies a charging voltage to the charging member;
a second voltage applying unit that applies a developing voltage to the developing member;
a third voltage applying unit that applies a toner supply voltage to the toner supply member;
a control unit that controls the first voltage application unit, the second voltage application unit , and the third voltage application unit ;
an image forming operation for forming the toner image on a recording material; and an operation different from the image forming operation, in which the toner contained in the toner container is supplied from the developing member to the surface of the image carrier. and an application operation of applying the metallic soap to the surface of the image carrier by:
When the difference between the surface potential of the surface of the image carrier charged by the charging member in the developing section and the developing voltage applied to the developing member by the second voltage applying section is defined as back contrast the control unit controls the back contrast in the coating operation to be greater than the back contrast in the image forming operation ;
In the application operation, the second voltage applying unit and the third voltage applying unit are arranged such that a potential difference in a direction in which an electrostatic force acts on the metallic soap in a direction from the toner supplying member toward the developing member is formed at the contact portion. and a voltage application unit of . In the rotation axis direction of the image carrier, the range of ten-point average surface roughness (Rz) of the surface of the image carrier is 0.10≦Rz≦0.70 (μm), and 7. The image forming apparatus according to claim 6 , wherein the range of the average interval (Sm) of the irregularities on the surface is 0<Sm≤70 ([mu]m). 8. The image forming apparatus according to claim 1, wherein in the coating operation, the developing member contacts the image carrier at the developing portion. The toner contains an organosilicon polymer,
9. The image forming apparatus according to claim 1, wherein the number of carbon atoms directly bonded to the silicon atoms of the organosilicon polymer is 1 to 3. 10. The image forming apparatus according to claim 9 , wherein the organosilicon polymer has a partial structure represented by R--SiO3/2 (R represents a hydrocarbon group having 1 to 6 carbon atoms). . 11. The image forming apparatus according to claim 10 , wherein said R is a hydrocarbon group having from 1 to 3 carbon atoms. an intermediate transfer member that forms a transfer portion in contact with the image carrier and carries the toner image formed on the surface of the image carrier at the transfer portion;
a transfer member for transferring the toner image carried on the intermediate transfer member onto a recording material;
exposing the surface of the image carrier on the downstream side of the transfer section in the rotation direction of the image carrier and on the upstream side of the charging section on the surface of the image carrier charged by the charging member; and an exposure unit for
12. The control section according to any one of claims 1 to 11 , wherein the control section performs control such that the exposure amount of the exposure unit in the coating operation is smaller than the exposure amount of the exposure unit in the image forming operation. 10. The image forming apparatus according to claim 1. 13. The image forming apparatus according to claim 12 , wherein the exposure unit does not perform exposure during the application operation. 14. The image forming apparatus according to claim 1, wherein the metal soap contains at least one of zinc, calcium, and magnesium. 15. The image forming apparatus according to claim 1, wherein the metal soap is at least one of zinc stearate, calcium stearate, and magnesium stearate. The image forming apparatus according to any one of claims 1 to 15 , wherein the metallic soap has a particle size of 0.15 µm or more and 2.0 µm or less. 17. The image forming apparatus according to any one of claims 1 to 16 , wherein the image carrier has a protective layer made of acrylic resin as an outermost layer.

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