JP2006259616A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that can improve picture quality of an image, maintain image stability for a long time, particularly, extends a photoreceptor life and a cleaning performance life, and is capable of forming a uniform image without a defect for a long time. <P>SOLUTION: The image forming apparatus is equipped with, as a cleaning means, at least a cleaning brush 701 which rotates while the bristles provided on the brush surface touch the surface a photoreceptor. The surface of the cleaning brush has at least two regions (A), (B) where diameters of bristles are different, along the rotation direction of the cleaning brush. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus.

  In recent years, so-called xerographic image forming apparatuses having charging means, exposure means, developing means, transfer means, and fixing means have been further increased in speed and longer life due to technical progress of each member and system. . As a result, the demand for high-speed compatibility and high reliability of each subsystem is increasing. In particular, photoconductors used for image writing and cleaners that clean the photoconductors are subject to many stresses due to sliding, and are liable to cause image defects due to scratches, wear, chipping, etc., and demands for high-speed compatibility and high reliability. Is stronger.

As a cleaning means for cleaning the photoconductor, various methods such as a method using a fur brush, a magnetic brush, and a method using an elastic cleaning blade are used, but the photoconductor is rubbed with the cleaning blade. The means for scraping off the toner is generally used because it is simple and inexpensive. Originally, the frictional resistance between the elastic blade and the photoconductor is large, and the elastic blade cannot be slid by itself, but fine particles such as silica added to the toner are released from the toner, and the elastic blade and the photoconductor It is thought that lubrication is carried out by interposing between them.
However, the inclusion of fine particles fluctuates depending on the image to be collected or is not supplied in non-image forming cycles, so the inclusion of lubrication components becomes unstable. In particular, it can be used under high-temperature and high-humidity conditions where frictional force increases and an alternating electric field is applied. In some cases, for example, when a contact charger such as a contact charging roll is used, friction between the elastic blade and the photosensitive member is locally increased. Due to the increase in friction, damage such as blade chattering, chipping of the cleaning edge, and wear occurs, and the removal performance of toner, toner components, and discharge products that must be cleaned is reduced and stable over a long period of time. The cleaning performance cannot be maintained. In addition, the friction of the cleaning blade is increased due to the increase in friction, so that the surface of the photoconductor may be scratched or wear may be accelerated.

In recent years, this type of image forming apparatus has been improved in image quality, and as one means for improving the image quality, a polymerization method is used to reduce the diameter of the toner, to make it spherical, and to narrow the particle size distribution. It has become like this. Reducing the toner diameter and narrowing the particle size distribution can improve the reproducibility of dots formed on the photoreceptor, and improving the developability and transferability by making the toner spherical.
However, since the toner having a narrow particle size distribution and a nearly spherical shape has better fluidity than the conventional irregularly pulverized toner, the toner retention at the cleaning edge of the blade is poor, and it is more difficult to ensure stable lubrication of the blade. In addition, blade cleaning of spherical toner is difficult, and particularly when the blade damage and the photoconductor scratch are deteriorated, the cleaning performance is remarkably deteriorated as compared with the conventional irregularly pulverized toner. Actually, it is difficult to extend the life of a process cartridge including a cleaning blade / photosensitive member due to this defective cleaning.

  On the other hand, when a fur brush is used, it is used in a high-speed system because there is no sudden failure due to chipping or the like generated in a blade cleaner and long life and reliability can be improved. However, when it is applied to a commonly used organic photoreceptor, it is easy to cause photoconductor scratches and filming due to a brush, and a sufficient lifespan is not always obtained.

In order to improve the wear resistance of the photoreceptor against these problems, a proposal has been made to extend the life of the photoreceptor by forming a protective layer with high wear resistance on the outermost layer of the amorphous silicon photoreceptor or organic photoreceptor. ing. For example, a photoconductor using a resin having a cross-linked structure and a structural unit having a charge transporting capability has been proposed as a long-life photoconductor (see, for example, Patent Document 1).
It has been found that these photoconductors are overwhelmingly superior in thermal and mechanical strength to conventional ones, so that deterioration due to abrasion of the surface layer can be remarkably reduced, and the life can be extended. However, these highly abrasion-resistant photoconductors have high strength and are not easily worn, so that the discharge products adhering particularly when the photoconductor is charged are hard to be removed from the surface of the photoconductor, and image flow due to moisture absorption of the discharge products is difficult. There was a problem that it was likely to occur.

In response to these problems, it has been proposed to warm the photoconductor with a heater or the like against image flow due to moisture absorption of the discharge product on the photoconductor using a siloxane resin having a crosslinked structure (for example, patents). (Ref. 2 or 3.)
It is possible to remove moisture absorbed by warming the photosensitive member with a heater or the like and effectively prevent image flow. However, this method increases the power consumption required by the image forming apparatus, and requires an arrangement of a heater inside the photosensitive member and a power supply mechanism for the heater, resulting in complicated apparatus and high cost. The problem remains.
Japanese Patent No. 3264218 JP 2000-241998 A JP 2002-91269 A

  The present invention has been made in view of the above-described conventional problems, and can improve image quality and maintain image stability over a long period of time. An object of the present invention is to provide an image forming apparatus capable of forming a uniform image without any problem.

That is, the present invention
<1> A photoconductor, a charging unit that uniformly charges the photoconductor, a latent image forming unit that forms a latent image on the surface of the charged photoconductor, and a latent image formed on the surface of the photoconductor Developing means for developing a toner image with a developer containing at least toner, a transfer means for transferring the toner image formed on the surface of the photosensitive member to a transfer target, and a transfer means to the transfer target. An image forming apparatus comprising at least a fixing unit for fixing the toner image and a cleaning unit for removing residual toner on the surface of the photoconductor after transfer, wherein the outermost surface layer of the photoconductor is a protective layer. And the cleaning means includes at least a cleaning brush that rotates while bringing the bristle provided on the surface into contact with the surface of the photoreceptor, and the cleaning brush is disposed on the surface of the cleaning brush. The image forming apparatus includes at least two regions in which the thickness of the bristle is different along a rotation direction of the paper.

  <2> The image forming apparatus according to <1>, wherein the brush hair is at least one selected from nylon, acrylic, polyolefin, and polyester.

  <3> The image forming apparatus according to <1> or <2>, wherein the brush hair is a conductive fiber, and further includes an application unit configured to apply a predetermined voltage between the photoconductor and the cleaning brush. .

  <4> The image forming apparatus according to any one of <1> to <3>, wherein the protective layer includes a resin having a crosslinked structure including a structural unit having charge transporting ability.

  <5> A phenol derivative or siloxane-based resin having a methylol group as a resin having a crosslink structure, wherein the structural unit having a charge transport capability includes a structural unit having a charge transport capability, and a hydroxyl group. And a charge transporting material having at least one selected from a carboxyl group, an alkoxysilyl group, an epoxy group, a thiol group, and an amino group.

  According to the present invention, an image forming apparatus capable of achieving high image quality and maintaining image stability over a long period of time, in particular, extending the life of the photoreceptor and the cleaning performance, and forming a uniform image without defects over a long period of time. Can be provided.

The image forming apparatus of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram according to an embodiment of an image forming apparatus of the present invention. The image forming apparatus of the present invention forms a latent image by exposing the photosensitive member 1, a charging device 2 that is a charging unit that uniformly charges the photosensitive member 1, and the photosensitive member 1 charged by the charging device 2. An exposure device 3 that is a latent image forming unit, a developing device 4 that is a developing unit that forms a toner image by developing a latent image formed by the exposure device 3 with a developer containing at least toner, and a developing device 4 A transfer device 5 that is a transfer unit that transfers the formed toner image to the transfer target P, a fixing device 6 that fixes the toner image transferred to the transfer target P by heat and / or pressure, and the like. And a cleaning device 7 which is a cleaning means for removing residual toner on the surface of the photoreceptor 1 by the cleaning brush according to the present invention.
The outermost surface layer of the photoreceptor 1 is a protective layer to be described later, whereby a photoreceptor having excellent wear resistance can be obtained.

  FIG. 2 is a schematic configuration diagram of the cleaning device 7. The cleaning device 7 shown in FIG. 2 is of a cartridge type and includes two cleaning units. That is, in FIG. 2, a housing 700 includes a first cleaning unit including a cleaning brush 701a, a recovery roll member 702a, and a scraper 703a, and a second cleaning unit including a cleaning brush 701b, a recovery roll member 702b, and a scraper 703b. Is housed. The side close to the photoreceptor 1 of the housing 700 is opened, and the outer peripheral surfaces (surfaces formed by the brush tips) of the cleaning brushes 701 a and 701 b are in contact with the outer peripheral surface of the photoreceptor 1 at the openings.

On the surface of the cleaning brush 701, there are at least two regions in which the thickness of the brush hair varies along the rotation direction of the cleaning brush 701. By configuring the surface of the cleaning brush 701 as described above, it is possible to achieve both cleaning of residual toner on the surface of the photoreceptor 1 and scraping of the discharge product.
3A to 3C are schematic views showing the cleaning brush 701. FIG. On the surface of the cleaning brush 701, there are two regions A (regions with thin brush hairs) and regions B (regions with thick brush hairs) along the rotation direction Z of the cleaning brush 701. The shape of the region A and the region B is not particularly limited, and examples thereof include a square shape (FIG. 3A), a strip shape (FIG. 3B), a spiral shape (FIG. 3C), and the like. However, it is not limited to these.

As the material for the brush hair, it is preferable to use at least one selected from nylon, acrylic, polyolefin, and polyester, since the brush hair is less likely to collapse or sag under long-term use, and maintenance of cleaning performance over a long period of time can be achieved. The material of the brush hair is more preferably nylon or polyester, particularly preferably nylon.
When combining thick and thin brush hair, a combination of 4 to 15 denier thick brush hair and 0.5 to 4 denier thin brush hair is preferred, and 4 to 8 denier thick brush hair and 1 to 3 denier brush hair is preferred. A combination of thin brush hairs is more preferable, and a combination of thick brush hairs of 4 to 6 denier and thin brush hair of 1 to 2 denier is particularly preferable.
The density of the brush hair is preferably 20,000 / inch ² or more, more preferably 60,000 / inch ² or more.

  As specific examples of the brush hair, commercially available products such as Beltron (manufactured by Kanebo), SA-7 (manufactured by Toray Industries, Inc.), and UU nylon (manufactured by Unitika) can be used as conductive nylon. These brush hairs (fibers) can be alternately attached to the shaft to produce a cleaning brush.

  The cleaning brush according to the present invention may be provided with three or more types of regions having different brush hair thicknesses. In this case, the surface of the cleaning brush may have all three or more types of regions having different bristle thicknesses along the rotation direction of the cleaning brush.

The mechanism of action of the cleaning brush according to the present invention is not necessarily clear, but will be described with reference to FIG. In FIG. 3C, regions A (regions with thin brush hairs) and regions B (regions with thick brush hairs) are alternately formed in a spiral shape. In general, increasing the fiber diameter of the brush increases the mechanical force on the photosensitive member and improves the scraping property of the toner and discharge products, but also increases the rubbing force and causes filming of toner components and the like. Therefore, it is extremely difficult to achieve both cleaning of residual toner and scraping of the discharge product with a brush having a single thickness of bristle.
In the present invention, a part of the toner, the toner component and the discharge product is removed in the region A (brush bristle region; low tip force), and firmly adhered in the region B (brush bristle region; high tip force). It is possible to remove discharge products. The area B is not always in contact with the photoconductor, thereby suppressing the occurrence of scratches on the photoconductor.
It is possible to use two brushes composed only of thin brush hairs and two brushes composed only of thick brush hairs, but in that case a separation mechanism for separating the brush composed only of thick brush hairs from the photoreceptor is necessary. There are problems such as becoming and space becoming larger.

  The cleaning brush 701a (or 701b) is formed in a roll shape by arranging a plurality of fibers on the outer peripheral surface of the shaft 704a (or 704b) from the center toward the outer peripheral surface. The shafts 704a and 704b are arranged in parallel to the tangent line to the photoreceptor 1, and the cleaning brushes 701a and 701b can rotate around the shafts 704a and 704b. The distance between each of the shafts 704a and 704b and the photosensitive member 1 is such that the amount of biting of the cleaning brush 701a and 701b at the brush tip with respect to the photosensitive member 1 is a predetermined value (preferably 0.3 to 2.0 mm, more preferably 0.5 to 1.8 mm).

  The recovery roll members 702a and 702b are obtained by curing a thermosetting resin and molding it into a roll shape and arranging it on the outer periphery of the shafts 705a and 705b. The collection roll member 702a (or 702b) has an outer peripheral surface that is in contact with the brush tip of the cleaning brush 701a (or 701b). The shaft 705a (or 705b) is disposed in parallel to the shaft 704a (or 704b), and the recovery roll member 702a (or 702b) can rotate about the shaft 705a (or 705b) as a rotation axis.

Examples of the thermosetting resin used for the collection roll members 702a and 702b include phenol resin, urea resin, melamine resin, unsaturated polyester, epoxy resin, and polyimide resin. Among them, the phenol resin is preferable because it has advantages such as high dimensional accuracy, easy molding, excellent surface smoothness of the molded body, and low cost.
The bending elastic modulus of the collection roll members 702a and 702b is preferably 700 kPa or more. When the flexural modulus is less than 700 kPa, the collection roll member is bent, and it is difficult to maintain the contact position and the amount of biting with the brush member or the blade member at a predetermined value. In addition, if a material having a flexural modulus of less than 700 kPa is used to increase the thickness of the recovery roll member to maintain rigidity, molding shrinkage increases, resulting in insufficient dimensional accuracy, and further increases the mass. Costs increase due to problems such as an increase in molding time and the need for subsequent processes. The flexural modulus here is a value measured in accordance with JIS K7203.

  Further, since the collection roll members 702a and 702b are in contact with the cleaning brushes 701a and 701b and the scrapers (blade members) 703a and 703b, respectively, the outer peripheral surfaces of the collection roll members 702a and 702b can be worn by the operation. In the present invention, when the amount of wear is measured in accordance with JIS K6902 on the outer peripheral surface of the recovery roll member, the amount of wear is preferably 20 mg or less. Thereby, the contact pressure and biting amount of the brush member and the blade member can be set to a large value, and even in that case, stable cleaning can be performed over a long period of time. If the amount of wear exceeds 20 mg, the life of the collecting roll member becomes insufficient and frequent replacement is required.

  Further, the Rockwell hardness (M scale) of the collection roll members 702a and 702b is preferably 100 or more. When the Rockwell hardness is 100 or more, molding with high dimensional accuracy is possible, and the roll member is extremely strong against scraping. Here, the Rockwell hardness is a value measured according to JIS K7202.

  The scrapers 703a and 703b are made of a thin metal plate, and are arranged so that an edge portion at one end thereof is in contact with the outer peripheral surface of the recovery roll members 702a and 702b. The other ends of the scrapers 703a and 703b are each fixed to the housing 700, but the fixing method thereof is not particularly limited, and may be fixed by using a mounting bracket 706 like the scraper 703a, or the housing like the scraper 703b. You may fix to 700 directly.

  The material of the scrapers 703a and 703b is preferably stainless steel or phosphor bronze from the viewpoint of high durability and low cost. The thickness of the scrapers 703a and 703b is preferably 0.02 to 2 mm, more preferably 0.05 to 1 mm. A blade member may be used instead of the scraper.

  In the cleaning device 7 having the above configuration, first, toner (residual toner) remaining on the photoreceptor 1 after the transfer process is removed by the cleaning brushes 701a and 701b. Next, the remaining toner is transferred to the contact position with the collection roll members 702a and 702b by the rotation of the cleaning brushes 701a and 701b and collected. As a result, the brush tips of the cleaning brushes 701 a and 701 b are regenerated and used repeatedly for cleaning the photosensitive member 1. The residual toner adhering to the collection roll members 702a and 702b is transferred to the contact position with the scrapers 703a and 703b by the rotation of the collection roll members 702a and 702b, and is removed by the scrapers 703a and 703b. As a result, the surfaces of the collection roll members 702a and 702b are also regenerated and repeatedly used for regenerating the brush tip of the cleaning brush.

  Here, in order to efficiently attract and move fine powders such as toner and paper powder electrostatically, cleaning with a potential difference between the cleaning brush 701a (or 701b) and the recovery roll member 702a (or 702b). A mechanism for applying a bias is preferable. More specifically, by applying a predetermined voltage to the cleaning brush 701a (or 701b), the residual toner on the photoreceptor 1 can be attached to the cleaning brush 701a (or 701b) by the electrostatic attraction force. . Then, by applying a voltage having an absolute value larger than the applied voltage to the cleaning brush 701a (or 701b) and the same polarity to the recovery roll member 702a (or 702b), the remaining attached to the cleaning brush 701a (or 701b). The toner can be attached to the collecting roll member 702a (or 702b). The potential difference (absolute value) between the cleaning brush and the collection roll member is preferably 100 V or more, more preferably 200 V or more, and further preferably 650 V.

When a voltage is applied to the cleaning brushes 701a and 701b, as a method for imparting conductivity to the brush hairs of the cleaning brush, a method in which conductive powder or an ionic conductive material is blended in the brush hairs, conductive inside or outside the brush hairs is conducted. Examples include a method of forming a layer. Further, the resistance value of the brush hair to which conductivity is imparted is preferably 10 ² to 10 ⁹ Ω · cm for a single fiber. Further, as a method for adjusting the electrical resistance of the collection roll members 702a and 702b, an inorganic filler and / or Or the method of filling with an organic filler, etc. are mentioned. When the collection roll member is filled with an inorganic filler or an organic filler, there is an advantage that the rigidity of the collection roll member is increased. Inorganic fillers include metal powders such as tin, iron, copper, and aluminum, metal fibers, glass fibers, magnetic powders, metal oxides such as zinc oxide, tin oxide, and titanium oxide, and metal sulfides such as copper sulfide and zinc sulfide. So-called hard ferrites such as strontium, barium and rare earth, magnetite, ferrites such as copper, zinc, nickel and manganese, or those whose surfaces are subjected to conductive treatment as required, copper, iron, manganese, nickel, zinc and cobalt Selected from oxides, hydroxides, carbonates or metal compounds containing different metal elements such as barium, aluminum, tin, lithium, magnesium, silicon, phosphorus, etc. Examples thereof include solid solutions, so-called composite metal oxides. Examples of the organic filler include carbon black, carbon powder, graphite, and polyaniline.

The resistance value when a voltage of 500 V is applied to the collection roll members 702a and 702b is preferably 1 × 10 ⁵ to 1 × 10 ¹⁰ Ω · cm, more preferably 1 × 10 ⁶ to 1 × 10 ⁸ Ω · cm. is there. When the resistance value is less than 1 × 10 ⁵ Ω · cm, charge injection into the collecting roll member occurs, and the polarity of fine powder such as toner and paper powder scraped by the cleaning brush is reversed. It becomes difficult to adsorb. On the other hand, if the electrical resistance of the collecting roll member exceeds 1 × 10 ¹⁰ Ω · cm, a phenomenon that charges are accumulated in the collecting roll member (charge-up) easily occurs. Becomes difficult to be electrically adsorbed.

The cleaning apparatus shown in FIG. 2 includes two cleaning units each including a cleaning brush, a collection roll member, and a scraper. However, in the present invention, the number of such cleaning units is not particularly limited. You may use the cleaning apparatus provided with these cleaning units. However, a device having a plurality of cleaning units such as the cleaning device 7 shown in FIG. 2 has the following advantages.
That is, the polarity of the toner (residual toner) remaining on the photoreceptor 1 after the transfer process is likely to vary due to the influence of the transfer electric field. That is, most of the residual toner exists with the positive electrode (original charged polarity) as it is, but a part of the residual toner may be reversed to the opposite polarity. In such a case, the cleaning unit including the cleaning brush 701a, the recovery roll member 702a, and the scraper 703a and the cleaning unit including the cleaning brush 701b, the recovery roll member 702b, and the scraper 703b are charged to different polarities, and one of them is a positive electrode. By using the remaining toner for the remaining toner and the remaining toner for the other reversed polarity, it is possible to efficiently remove both the remaining toner of the positive electrode and the remaining toner of the opposite polarity. More specifically, first, in the second cleaning unit, a cleaning bias having a polarity different from that of the toner is applied to the cleaning brush 701b and the recovery roll 702b to electrostatically adsorb the positive toner occupying most of the remaining toner. Move. Next, in the first cleaning unit, it is effective to electrostatically attract and move the toner reversed to the opposite polarity by applying a cleaning bias having the same polarity as the toner to the cleaning brush 701a and the collecting roll 702a. .

  In the image forming apparatus of the present invention, it is preferable to further include an application unit that uses conductive fibers as the brush bristles of the cleaning brush and applies a predetermined voltage between the photoreceptor 1 and the cleaning brush 701. By providing a potential difference between the photosensitive member 1 and the cleaning brush 701 by the applying means, a desired electric field can be stably formed between the brush and the photosensitive member by adjusting the resistance of the conductive brush. The reliability of the cleaning property is improved.

Next, components other than the cleaning device in the image forming apparatus according to FIG. 1 will be described.
The photosensitive member 1 is charged by using the charging device 2, and as a charging means, a voltage is applied to a non-contact type charger such as corotron or scorotron and a conductive member in contact with the surface of the photosensitive member. Therefore, a contact-type charger for charging the photosensitive member can be used, and any type of charger may be used. However, a contact charging type charging device is preferred from the viewpoint of producing an effect that the amount of ozone generated is small, is environmentally friendly and has excellent printing durability.
In the contact charging type charging device, the shape of the conductive member may be any of a brush shape, a blade shape, a pin electrode shape, a roller shape, and the like, and is not limited.

  A latent image is formed on the surface of the charged photoreceptor 1 using the exposure device 3. As the exposure apparatus 3, for example, a laser optical system, an LED array, or the like is used.

The latent image formed on the surface of the photoreceptor 1 is developed with a developer containing at least a toner to form a toner image. For example, a developer carrying member having a developer layer formed on the surface thereof is brought into contact with or close to the photoreceptor 1, and toner is attached to the latent image on the surface of the photoreceptor 1 to form a toner image.
As the developing device 4, a known device can be used, but examples of the developing device using a two-component developer include a developing device such as a cascade method and a magnetic brush method.

  The toner image formed on the surface of the photoreceptor 1 is transferred to the transfer target P by the transfer device 5. A corotron can be used as the transfer device 5 that transfers the toner image from the photoreceptor 1 to the transfer target P. The corotron is effective as a means for uniformly charging the transfer material P, but in order to give a predetermined charge to the transfer material P, a high voltage of several kV must be applied and a high voltage power source is required. . In addition, ozone is generated by corona discharge, which may cause deterioration of rubber parts and the photoconductor 1. Therefore, a conductive transfer roll made of an elastic material is pressed against the photoconductor 1 to transfer the toner image onto the paper. However, in the image forming method of the present invention, the transfer device is not particularly limited.

  The toner image transferred to the transfer target P is fixed by the fixing device 6. As the fixing device 6, a heat fixing device using a heat roll is preferably used. The heat fixing device includes a fixing roller having a heater lamp for heating inside a cylindrical metal core, a so-called release layer formed on the outer peripheral surface by a heat resistant resin film layer or a heat resistant rubber film layer, and the fixing roller. The pressure roller or pressure belt is disposed in pressure contact with the roller and has a heat-resistant elastic body layer formed on the outer peripheral surface of the cylindrical metal core or the surface of the belt-like base material. In the fixing process of an unfixed toner image, a transfer material on which an unfixed toner image is formed is inserted between a fixing roller and a pressure roller or a pressure belt, and a binder resin, an additive, etc. Fix by heat melting. In the image forming apparatus of the present invention, the fixing device 6 is not particularly limited.

The photoreceptor 1 is not particularly limited as long as it has a protective layer on the outermost surface layer, but is not limited to a conductive substrate, a photosensitive layer formed on the conductive substrate, and the charge transport layer. It is preferable to have at least a surface layer (protective layer) formed on the surface.
The photosensitive layer may be composed of only one layer, or may be a function-separated type photosensitive layer composed of a charge generation layer and a charge transport layer. When the photosensitive layer is a function separation type, a mode in which a charge generation layer and a charge transport layer are laminated in this order from the conductive substrate side is preferable.

Examples of conductive substrates include metal plates, metal drums, metal belts, or conductive polymers using metals or alloys such as aluminum, copper, zinc, stainless steel, chromium, nickel, molybdenum, vanadium, indium, gold, platinum, etc. In addition, a paper, a plastic film, a belt, or the like coated, vapor-deposited, or laminated with a conductive compound such as indium oxide or a metal or alloy such as aluminum, palladium, or gold.
When the photoreceptor is used in a laser printer, the laser oscillation wavelength is preferably from 350 nm to 850 nm, and the shorter wavelength is preferable because the resolution is excellent. In order to prevent interference fringes generated when laser light is irradiated, the surface of the conductive substrate is preferably roughened to a center line average roughness Ra of 0.04 μm to 0.5 μm. As a roughening method, wet honing performed by suspending an abrasive in water and spraying the substrate, or centerless grinding, anodizing, in which a substrate is pressed against a rotating grindstone, and grinding is continuously performed, It is preferable to prepare a layer containing treatment with an acidic treatment liquid, boehmite treatment, organic or inorganic semiconductive fine particles, and the like. If Ra is smaller than 0.04 μm, the effect of preventing interference cannot be obtained because it is close to a mirror surface, and if Ra is larger than 0.5 μm, the image quality becomes rough even if a film is formed on the conductive substrate, which is not suitable. . When non-interfering light is used as a light source, it is not particularly necessary to roughen the interference fringes, and it is possible to prevent the occurrence of defects due to irregularities on the surface of the conductive substrate.

  The anodizing treatment is to form an oxide film on the aluminum surface by anodizing in an electrolyte solution using aluminum as an anode. Examples of the electrolyte solution include a sulfuric acid solution and an oxalic acid solution. However, the intact porous anodic oxide film is chemically active, easily contaminated, and has a large resistance fluctuation due to the environment. Therefore, the pores in the anodized film are sealed with pressurized water vapor or boiling water (a metal salt such as nickel may be added) by volume expansion due to a hydration reaction, and a sealing process is performed to change to a more stable hydrated oxide. . The thickness of the anodic oxide film is preferably 0.3 to 15 μm. When it is thinner than 0.3 μm, the barrier property against injection is poor and the effect is not sufficient. On the other hand, if it is thicker than 15 μm, the residual potential increases due to repeated use.

  Moreover, the treatment of the conductive substrate with an acidic treatment liquid comprising phosphoric acid, chromic acid and hydrofluoric acid is carried out as follows. The mixing ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acidic treatment liquid is such that phosphoric acid is in the range of 10 to 11% by mass, chromic acid is in the range of 3 to 5% by mass, and hydrofluoric acid is in the range of 0.5 to 2% by mass. The concentration of these acids as a whole is preferably in the range of 13.5 to 18% by mass. The processing temperature is 42 to 48 ° C., but by keeping the processing temperature high, a thicker film can be formed faster. About the film thickness of a film, 0.3-15 micrometers is preferable. When it is thinner than 0.3 μm, the barrier property against injection is poor and the effect is not sufficient. On the other hand, if it is thicker than 15 μm, the residual potential increases due to repeated use.

  The boehmite treatment of the conductive substrate can be performed by immersing in pure water at 90 to 100 ° C. for 5 to 60 minutes or by contacting with heated steam at 90 to 120 ° C. for 5 to 60 minutes. About the film thickness of a film, 0.1-5 micrometers is preferable. This can be further anodized using an electrolyte solution with low film solubility such as adipic acid, boric acid, borate, phosphate, phthalate, maleate, benzoate, tartrate, citrate. Good.

  Examples of organic or inorganic semiconductive fine particles include perylene pigments, bisbenzimidazole perylene pigments, polycyclic quinone pigments, indigo pigments, quinacridone pigments, and the like described in JP-A-47-30330. And organic pigments such as bisazo pigments and phthalocyanine pigments having electron-withdrawing substituents such as nitro, nitroso and halogen atoms, and inorganic pigments such as zinc oxide, titanium oxide and aluminum oxide. Among these pigments, zinc oxide and titanium oxide are preferable because they have high charge transporting ability and are effective for thickening. The surface of these pigments may be surface-treated with an organic titanium compound such as a titanate coupling agent, an aluminum chelate compound or an aluminum coupling agent for the purpose of improving dispersibility or adjusting the energy level, in particular vinyltrichlorosilane. , Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ -Chloropropyltrimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, β-3,4-epoxysilane It is preferable to treat with a silane coupling agent such as cyclohexyl trimethoxysilane.

As a method for mixing / dispersing the organic or inorganic semiconductive fine particles, a method using a ball mill, a roll mill, a sand mill, an attritor, an ultrasonic wave, or the like is applied. Mixing / dispersing is carried out in an organic solvent. As the organic solvent, an organic metal compound or resin is dissolved, and no gelation or aggregation occurs when organic / inorganic semiconductive fine particles are mixed / dispersed. Anything can be used.
For example, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene Ordinary organic solvents such as toluene can be used alone or in admixture of two or more.

If desired, an undercoat layer can be formed between the conductive substrate and the photosensitive layer.
Materials used include zirconium chelate compounds, zirconium alkoxide compounds, organic zirconium compounds such as zirconium coupling agents, titanium chelate compounds, titanium alkoxide compounds, organic titanium compounds such as titanate coupling agents, aluminum chelate compounds, aluminum coupling agents, etc. In addition to organic aluminum compounds, antimony alkoxide compounds, germanium alkoxide compounds, indium alkoxide compounds, indium chelate compounds, manganese alkoxide compounds, manganese chelate compounds, tin alkoxide compounds, tin chelate compounds, aluminum silicon alkoxide compounds, aluminum titanium alkoxide compounds, aluminum Zirconium alkoxide compounds, etc. Machine metal compounds. In particular, organozirconium compounds, organotitanium compounds, and organoaluminum compounds are preferably used because of their low residual potential and good electrophotographic characteristics.

In addition, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyl Triethoxysilane, γ-chloropropyltrimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, β-3,4-epoxycyclohexyltrimethoxy It can be used by containing a silane coupling agent such as silane.
Furthermore, polyvinyl alcohol, polyvinyl methyl ether, poly-N-vinyl imidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, polyamide, polyimide, casein, gelatin, polyethylene, polyester, conventionally used for the undercoat layer Further, known binder resins such as phenol resin, vinyl chloride-vinyl acetate copolymer, epoxy resin, polyvinyl pyrrolidone, polyvinyl pyridine, polyurethane, polyglutamic acid, and polyacrylic acid can also be used. These mixing ratios can be appropriately set as necessary.

Further, an electron transporting pigment may be mixed / dispersed in the undercoat layer. Examples of the electron transport pigment include organic pigments such as perylene pigments, bisbenzimidazole perylene pigments, polycyclic quinone pigments, indigo pigments, quinacridone pigments described in JP-A-47-30330, cyano groups, nitro groups, Examples thereof include organic pigments such as bisazo pigments and phthalocyanine pigments having electron-withdrawing substituents such as nitroso groups and halogen atoms, and inorganic pigments such as zinc oxide and titanium oxide. Among these pigments, perylene pigments, bisbenzimidazole perylene pigments and polycyclic quinone pigments, zinc oxide, and titanium oxide are preferably used because of their high electron mobility. Further, the surface of these pigments may be surface-treated with the above-mentioned coupling agent or binder for the purpose of controlling dispersibility and charge transport property.
As a method for mixing / dispersing the electron transporting pigment, a conventional method using a ball mill, a roll mill, a sand mill, an attritor, an ultrasonic wave, or the like is applied. Mixing / dispersing is carried out in an organic solvent, as long as the organic solvent dissolves an organometallic compound or resin and does not cause gelation or aggregation when an electron transporting pigment is mixed / dispersed. Anything can be used. For example, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene Ordinary organic solvents such as toluene can be used alone or in admixture of two or more. The thickness of the undercoat layer is generally 0.1 to 30 μm, preferably 0.2 to 25 μm.

  In addition, as the coating method used when the undercoat layer is provided, conventional methods such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method are used. Can be used. The coated layer is dried to obtain an undercoat layer. Usually, the drying is performed at a temperature at which the solvent can be evaporated to form a film. In particular, a conductive substrate that has been subjected to an acid solution treatment or a boehmite treatment is preferably formed with an undercoat layer because the defect concealing power of the conductive substrate tends to be insufficient.

  Examples of the charge generation material used in the charge generation layer include azo pigments such as bisazo and trisazo, condensed aromatic pigments such as dibromoanthanthrone, perylene pigments, pyrrolopyrrole pigments, organic pigments such as phthalocyanine pigments, trigonal selenium, Although all known ones such as inorganic pigments such as zinc oxide can be used, inorganic pigments are particularly preferred when using an exposure wavelength of 380 nm to 500 nm, and metals and non-organic pigments are used when using an exposure wavelength of 700 nm to 800 nm. Metal phthalocyanine pigments are preferred. Among these, hydroxygallium phthalocyanine disclosed in JP-A-5-263007 and JP-A-5-279591, chlorogallium phthalocyanine disclosed in JP-A-5-98181, JP-A-5-140472 and Particularly preferred are dichlorotin phthalocyanine disclosed in JP-A-5-140473, titanyl phthalocyanine disclosed in JP-A-4-189873 and JP-A-5-43813.

The binder resin can be selected from a wide range of insulating resins. It can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and polysilane. Preferred binder resins include polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin. Insulating resin such as polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin can be used, but is not limited thereto. These binder resins can be used alone or in admixture of two or more.
The blending ratio (mass ratio) between the charge generating material and the binder resin is preferably in the range of 10: 1 to 1:10. In addition, as a method for dispersing them, a usual method such as a ball mill dispersion method, an attritor dispersion method, a sand mill dispersion method, or the like can be used. It is said. In addition, it has been confirmed that the crystal form is not changed from that before dispersion in any of the dispersion methods implemented in the present invention. Further, at the time of this dispersion, it is effective to make the particles have a particle size of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

Moreover, as a solvent used for these dispersions, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran Ordinary organic solvents such as methylene chloride, chloroform, chlorobenzene and toluene can be used alone or in admixture of two or more.
The thickness of the charge generation layer used in the present invention is generally 0.1 to 5 μm, preferably 0.2 to 2.0 μm. In addition, as a coating method used when the charge generation layer is provided, usual methods such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method are used. Can be used.

As the charge transport layer of the photoreceptor, those formed by a known technique can be used. These charge transport layers are formed containing a charge transport material and a binder resin, or are formed containing a polymer charge transport material.
Charge transport materials include quinone compounds such as p-benzoquinone, chloranil, bromanyl, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, xanthone compounds, benzophenone compounds , Electron transport compounds such as cyanovinyl compounds and ethylene compounds, triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, etc. Examples thereof include pore-transporting compounds. These charge transport materials can be used alone or in combination of two or more, but are not limited thereto. In addition, these charge transport materials can be used alone or in combination of two or more, but those having the following structure are preferred from the viewpoint of mobility.

(In the formula, R ¹⁴ represents a hydrogen atom or a methyl group, and n represents 1 or 2. Ar ₆ and Ar ₇ represent a substituted or unsubstituted aryl group, or —C (R ¹⁸ ) ═C (R ¹⁹ ) (R ²⁰ ), —CH═CH—CH═C (Ar) ₂ , wherein R ¹⁸ , R ¹⁹ and R ²⁰ are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl Ar represents a substituted or unsubstituted aryl group, including a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or carbon A substituted amino group substituted with an alkyl group having a number in the range of 1 to 3 is shown.)

(Wherein R ¹⁵ and R ^{15 ′} may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. R ¹⁶ , R ^{16 ′} , R ¹⁷ and R ^{17 ′} may be the same or different, and an amino group substituted with a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 1 to 2 carbon atoms. Represents a substituted or unsubstituted aryl group, or —C (R ¹⁸ ) ═C (R ¹⁹ ) (R ²⁰ ), —CH═CH—CH═C (Ar) ₂ , R ¹⁸ , R ¹⁹ , R ²⁰ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, Ar represents a substituted or unsubstituted aryl group, and m and n are integers of 0 to 2.)

(In the formula, R ₂₁ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted aryl group, or —CH═CH—CH═C (Ar) ₂ . Ar represents a substituted or unsubstituted aryl group, and R ₂₂ and R ₂₃ may be the same or different, and may be a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. Group, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, or a substituted or unsubstituted aryl group.)

  Further, the binder resin used for the charge transport layer is polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride- Acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N- Vinyl carbazole, polysilane, and polymer charge transport materials such as polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 can also be used. These binder resins can be used alone or in admixture of two or more. The blending ratio (mass ratio) between the charge transport material and the binder resin is preferably 10: 1 to 1: 5.

  A polymer charge transport material can also be used alone. As the polymer charge transporting material, known materials having charge transporting properties such as poly-N-vinylcarbazole and polysilane can be used. In particular, polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 have a high charge transporting property and are particularly preferable. The polymer charge transport material alone can be used as the charge transport layer, but it may be formed by mixing with the binder resin.

The thickness of the charge transport layer used in the present invention is generally 5 to 50 μm, preferably 10 to 30 μm. As a coating method, a normal method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method can be used.
Solvents used when providing the charge transport layer include aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, and halogenated fats such as methylene chloride, chloroform and ethylene chloride. Ordinary organic solvents such as aromatic hydrocarbons, cyclic ethers such as tetrahydrofuran and ethyl ether, or straight-chain ethers can be used alone or in admixture of two or more.

  In addition, additives such as antioxidants, light stabilizers, and heat stabilizers are added to the photosensitive layer for the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, or light or heat generated in the image forming apparatus. Can be added. For example, examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds. Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine. In addition, at least one kind of electron accepting substance can be contained for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use.

Examples of the electron acceptor usable in the photoconductor according to the present invention include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, phthalic acid and the like, and compounds represented by the general formula (I) described later Can give. Of these, benzene derivatives having electron-withdrawing substituents such as fluorenone, quinone and Cl, CN, NO ₂ are particularly preferred.

  As the protective layer according to the present invention, a conductive resin dispersed in a binder resin, a lubricating charge such as a fluororesin and an acrylic resin dispersed in a normal charge transport layer material, silicon, acrylic, etc. A hard coating agent can be used, but those having a crosslinked structure are preferred from the viewpoint of film strength.

  Various materials can be used for forming the crosslinked structure, but phenolic resins, siloxane resins, urethane resins, epoxy resins, and the like are preferable in terms of characteristics, and those made of phenolic resins or siloxane-based resins are particularly preferable. In addition to the resin having a crosslinked structure, the protective layer includes a binder resin not having a crosslinked structure, conductive fine particles, and lubricating fine particles made of a fluororesin or an acrylic resin, if necessary. In forming the outermost surface layer, a hard coat agent such as silicon or acrylic can be used as necessary. The details of the method for forming the outermost surface layer will be described later. For the formation of the outermost surface layer, a solution for forming the outermost surface layer containing at least a precursor constituting a resin having a crosslinked structure is used.

  Furthermore, from the viewpoint of electrical characteristics, image quality maintenance, etc., it is preferable that the outermost surface layer (protective layer) contains a structural unit having a charge transport ability and a resin having a crosslinked structure.

  The structural unit having a charge transporting ability that includes a structural unit having such a charge transporting ability and constituting a resin having a crosslinked structure is a phenol derivative or siloxane-based resin having a methylol group as a resin having a crosslinked structure, a hydroxyl group, More preferably, it contains a charge transport material having at least one selected from a carboxyl group, an alkoxysilyl group, an epoxy group, a thiol group and an amino group. Furthermore, since the infrared absorption spectrum (IR spectrum) of the phenol derivative-containing layer as the protective layer satisfies the condition represented by the following formula, the electrical characteristics are excellent, and high image quality can be achieved.

        (P2 / P1) ≦ 0.2

Wherein, P1 is the absorbance of the maximum absorption peaks at 1560cm ^-1 ~1640cm ^-1, P2 represents the absorbance of the maximum absorption peaks at 1645cm ^-1 ~1700cm ^-1. ]

The reason why the above-described effect is obtained by the above formula is not necessarily clear, but the present inventors infer as follows.
That is, in the process of forming a coating film using a phenol derivative having a methylol group, it is considered that a part of the methylol group of the phenol derivative becomes an oxide such as a formyl group. Such an oxide such as a formyl group is considered to act as a carrier trap that hinders charge transport in the photoconductor, thereby reducing the electrical characteristics of the photoconductor. Here, in the infrared absorption spectrum, the maximum absorption peaks at 1560cm ^-1 ~1640cm ^-1 (P1) corresponds to the aromatic C-C stretching vibration of a phenol derivative. The maximum absorption peaks at 1645cm ^-1 ~1700cm ^-1 (P2) is thought to be derived from the oxide such as a formyl group.

That is, it is considered that a photoconductor having a small absorbance ratio (P2 / P1) has few oxides such as formyl groups in the photoconductor and is excellent in carrier transportability. The photoreceptor according to the present invention uses the above-mentioned specific material and has an absorbance ratio (P2 / P1) of 0.2 or less. Therefore, it is considered that the photoreceptor has excellent electrical characteristics and high image quality. The photoreceptor according to the present invention is excellent in mechanical strength as well as electrical characteristics, and this is also considered to be a factor in achieving high image quality.
The absorbance ratio (P2 / P1) is preferably 0.18 or less, and more preferably 0.17 or less. When the absorbance ratio (P2 / P1) exceeds 0.2, the carrier transportability is lowered, the electrical characteristics of the photoreceptor are insufficient, and the image quality is lowered.

  Examples of the phenol derivative having a methylol group include monomers of monomethylolphenols, dimethylolphenols or trimethylolphenols, mixtures thereof, oligomers thereof, or mixtures of these monomers and oligomers. Such phenol derivatives having a methylol group include resorcin, bisphenol, etc., substituted phenols containing one hydroxyl group such as phenol, cresol, xylenol, paraalkylphenol, paraphenylphenol, and two hydroxyl groups such as catechol, resorcinol, hydroquinone, etc. It is obtained by reacting a compound having a phenol structure, such as substituted phenols, bisphenol A, bisphenol Z, and the like having a phenol structure with formaldehyde, paraformaldehyde, etc. in the presence of an acid catalyst or an alkali catalyst, Generally what is marketed as a phenol resin can also be used. In the present specification, a relatively large molecule having about 2 to 20 repeating molecular structural units is referred to as an oligomer, and a molecule smaller than that is referred to as a monomer.

As the acid catalyst, sulfuric acid, paratoluenesulfonic acid, phosphoric acid and the like are used. As the alkali catalyst, hydroxides or amine catalysts of alkali metals and alkaline earth metals such as NaOH, KOH, Ca (OH) ₂ and Ba (OH) ₂ are used.
Examples of the amine catalyst include, but are not limited to, ammonia, hexamethylenetetramine, trimethylamine, triethylamine, and triethanolamine. When a basic catalyst is used, the carrier is remarkably trapped by the remaining catalyst, and the electrophotographic characteristics tend to be deteriorated. Therefore, it is preferable to inactivate or remove by neutralizing with an acid or contacting with an adsorbent such as silica gel or an ion exchange resin.
Moreover, as a phenol derivative which has a methylol group, a phenol resin is preferable and a resol type phenol resin is more preferable.

  As the charge transport material having at least one selected from a hydroxyl group, a carboxyl group, an alkoxysilyl group, an epoxy group, a thiol group and an amino group, compounds represented by the following general formula (I), (II) or (III) It is preferable that

_{^{F - [(X 1) m1}} - (R 1) m2 -Y] m3 (I)

In the above formula (I), F is an organic group derived from a compound having a hole transporting ability, X ¹ is an oxygen atom or a sulfur atom, R ¹ is an alkylene group (the number of carbon atoms is preferably 1 to 15, preferably 1 10 is more preferable), Y represents a hydroxyl group, a carboxyl group (—COOH), a thiol group (—SH) or an amino group (—NH ₂ ), m1 and m2 each independently represents 0 or 1, m3 represents An integer of 1 to 4 is shown.

_{^{F - [(X 2) n1}} - (R 2) n2 - (Z) n3 G] n4 (II)

In the above formula (II), F represents an organic group derived from a compound having a hole transporting ability, X ² represents an oxygen atom or a sulfur atom, R ² represents an alkylene group (preferably having 1 to 15 carbon atoms, 1 10 is more preferable), Z is an alkylene group, oxygen atom, sulfur atom, NH or COO, G is an epoxy group, n1, n2 and n3 are each independently 0 or 1, n4 is 1-4 Indicates an integer.

F- [D-Si (R ³ ) _(3-a) Q _a ] _b (III)

In formula (III), F represents an organic group derived from a compound having a hole transporting ability, D represents a divalent group having flexibility, R ³ represents a hydrogen atom, a substituted or unsubstituted alkyl group ( The number of carbon atoms is preferably 1-15, more preferably 1-10, or a substituted or unsubstituted aryl group (carbon number is preferably 6-20, more preferably 6-15), and Q is a hydrolyzable group. A represents an integer of 1 to 3, and b represents an integer of 1 to 4.

In addition, as the divalent group D having flexibility, specifically, a site of F for imparting photoelectric characteristics, a substituted silicon group contributing to the construction of a three-dimensional inorganic glassy network, It is a divalent group that plays a role in linking. In addition, D represents an organic group structure that imparts moderate flexibility to the portion of the inorganic glassy network that is hard but brittle, and plays a role of improving mechanical toughness as a film. Specific examples _{D, -CαH 2 α -, -} CβH 2 β -2 -, - CγH 2 γ -4 - 2 divalent hydrocarbon group (here represented by, alpha is an integer from 1 to 15 , Β represents an integer of 2 to 15, and γ represents an integer of 3 to 15), —COO—, —S—, —O—, —CH ₂ —C ₆ H ₄ —, —N═CH—, -(C ₆ H ₄ )-(C ₆ H ₄ )-and a characteristic group having a structure in which these characteristic groups are arbitrarily combined, and further, constituent atoms of these characteristic groups are substituted with other substituents And the like. The hydrolyzable group Q is preferably an alkoxy group, more preferably an alkoxy group having 1 to 15 carbon atoms.

  As the organic group F derived from the compound having a hole transport ability in the compounds represented by the general formulas (I) to (III), a compound represented by the following general formula (VI) is preferable.

Here, in the formula (VI), Ar ¹ , Ar ² , Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted aryl group, and Ar ⁵ represents a substituted or unsubstituted aryl group or arylene group. ^{1 to} 4 of Ar ^{1 to} Ar ⁵ are-[(X ¹ ) _m1- (R ¹ ) _m2 -Y],-[(X _{^{2) n1 - (R 2)}} n2 - (Z) n3 G], or - has a portion with a bond represented by ^{[D-Si (R 3)} (3-a) Q a].

  In addition, conductive particles may be added to the protective layer in order to lower the residual potential. Examples of the conductive particles include metals, metal oxides, and carbon black. Among these, metals or metal oxides are more preferable. Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver, and stainless steel, or those obtained by depositing these metals on the surface of plastic particles. Examples of the metal oxide include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony and tantalum-doped tin oxide, and antimony-doped zirconium oxide. It is done. These can be used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion. From the viewpoint of the transparency of the protective layer, the volume average particle size of the conductive particles is preferably 0.3 μm or less, and particularly preferably 0.1 μm or less.

  In addition, a compound represented by the following general formula (VII-1) can also be added to the protective layer in order to control various physical properties such as strength and film resistance of the protective layer.

Si (R ³⁰ ) _(4-c) Q _c (VII-1)

In the above formula (VII-1), R ³⁰ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and c represents an integer of 1 to 4.

  Specific examples of the compound represented by the general formula (VII-1) include the following silane coupling agents. Examples of silane coupling agents include tetrafunctional silanes such as tetramethoxysilane and tetraethoxysilane (c = 4); methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, methyltrimethoxyethoxysilane, vinyltri Methoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxy Silane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, (tridecafluoro-1,1,2,2-tetrahydrooctyl L) Triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (heptafluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H , 1H, 2H, 2H-perfluorodecyltriethoxysilane, trifunctional alkoxysilane such as 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (c = 3); dimethyldimethoxysilane, diphenyldimethoxysilane, methyl And bifunctional alkoxysilanes such as phenyldimethoxysilane (c = 2); monofunctional alkoxysilanes such as trimethylmethoxysilane (c = 1), and the like. Trifunctional and tetrafunctional alkoxysilanes are preferable for improving the strength of the film, and monofunctional and bifunctional alkoxysilanes are preferable for improving the flexibility and film formability.

  In addition, a silicon-based hard coat agent produced mainly from these coupling agents can also be used. Commercially available hard coat agents include KP-85, X-40-9740, X-40-2239 (manufactured by Shin-Etsu Silicone), and AY42-440, AY42-441, AY49-208 (manufactured by Toray Dow Corning). Etc.) can be used.

  In order to increase the strength of the protective layer, it is also preferable to use a compound having two or more silicon atoms as shown in the general formula (VII-2).

B- (Si (R ³¹ ) _(3-d) Q _d ) ₂ (VII-2)

In the above formula (VII-2), B represents a divalent organic group, R ³¹ represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and d represents 1 to 3. Indicates an integer.

  The protective layer has a cyclic compound having a repeating structural unit represented by the following general formula (VII-3) for extending pot life, controlling film characteristics, reducing torque, and improving the uniformity of the coating film surface, or Derivatives from the compounds can also be included.

In the above formula (VII-3), A ¹ and A ² each independently represent a monovalent organic group.

  Commercially available cyclic siloxane can be mentioned as a cyclic compound which has a repeating structural unit shown by general formula (VII-3). Specifically, cyclic dimethylcyclosiloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, 1,3,5-trimethyl-1,3,5- Triphenylcyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclotetrasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7 , 9-pentaphenylcyclopentasiloxane and other cyclic methylphenylcyclosiloxanes, hexaphenylcyclotrisiloxane and other cyclic phenylcyclosiloxanes, and 3- (3,3,3-trifluoropropyl) methylcyclotrisiloxane and other fluorine Atom-containing cyclosiloxanes, methylhydrosiloxa Mixture, pentamethylcyclopentasiloxane, mention may be made of phenyl hydrosilyl group-containing cyclosiloxanes of hydrocyclosiloxane like, cyclic siloxanes and vinyl group-containing cyclosiloxanes such as penta vinyl pentamethylcyclopentasiloxane like. These cyclic siloxane compounds may be used alone or in combination of two or more.

  Furthermore, various fine particles can be added in order to control the contamination resistance adhesion, lubricity, hardness, etc. of the photoreceptor surface. They can be used alone or in combination of two or more.

Examples of the fine particles include silicon atom-containing fine particles. The silicon atom-containing fine particles are fine particles containing silicon as a constituent element, and specific examples include colloidal silica and silicone fine particles. The colloidal silica used as the silicon atom-containing fine particles preferably has a volume average particle diameter of 1 to 100 nm, more preferably 10 to 30 nm, in an acidic or alkaline aqueous dispersion, or an organic solvent such as alcohol, ketone or ester. It is selected from those dispersed in, and commercially available products can be used. The solid content of colloidal silica in the protective layer is not particularly limited, but preferably 0.1 to 50 mass based on the total solid content of the protective layer in terms of film formability, electrical properties, and strength. %, More preferably 0.1 to 30% by mass.
The silicone fine particles used as the silicon atom-containing fine particles are spherical and preferably have a volume average particle size of 1 to 500 nm, more preferably 10 to 100 nm, and are selected from silicone resin particles, silicone rubber particles, and silicone surface-treated silica particles. A commercially available product can be used.

  Silicone fine particles are small particles that are chemically inert and excellent in dispersibility in resins, and because the content required to obtain sufficient properties is low, photosensitivity can be achieved without inhibiting the crosslinking reaction. The surface properties of the body can be improved. That is, it is possible to improve the lubricity and water repellency of the surface of the photoreceptor while being uniformly incorporated into a strong cross-linked structure, and maintain good wear resistance and contamination resistance adhesion over a long period of time. The content of the silicone fine particles in the protective layer is preferably in the range of 0.1 to 30% by mass, more preferably in the range of 0.5 to 10% by mass, based on the total solid content of the protective layer.

Other fine particles include fluorine-based fine particles such as ethylene tetrafluoride, trifluoride ethylene, propylene hexafluoride, vinyl fluoride, vinylidene fluoride, and the 8th Polymer Materials Forum Lecture Proceedings p89. Fine particles made of a resin obtained by copolymerizing a fluororesin and a monomer having a hydroxyl group, ZnO—Al ₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ —SnO ₂ , ZnO—TiO ₂ , MgO _{-Al 2 O 3, FeO-TiO} 2, TiO 2, SnO 2, in 2 O 3, ZnO, mention may be made of semi-conductive metal oxides such as MgO. For the same purpose, an oil such as silicone oil can be added.

  Examples of the silicone oil include silicone oils such as dimethylpolysiloxane, diphenylpolysiloxane, and phenylmethylsiloxane, amino-modified polysiloxane, epoxy-modified polysiloxane, carboxyl-modified polysiloxane, carbinol-modified polysiloxane, methacryl-modified polysiloxane, and mercapto. Examples include reactive silicone oils such as modified polysiloxanes and phenol-modified polysiloxanes. These may be added in advance to the protective layer-forming coating solution, or may be impregnated under reduced pressure or increased pressure after producing the photoreceptor.

  In addition, additives such as plasticizers, surface modifiers, antioxidants, and photodegradation inhibitors can also be used. Examples of the plasticizer include biphenyl, biphenyl chloride, terphenyl, dibutyl phthalate, diethylene glycol phthalate, dioctyl phthalate, triphenyl phosphate, methyl naphthalene, benzophenone, chlorinated paraffin, polypropylene, polystyrene, and various fluorohydrocarbons. An antioxidant having a hindered phenol, hindered amine, thioether or phosphite partial structure can be added to the protective layer, which is effective in improving the potential stability and image quality when the environment changes.

  Examples of the antioxidant include the following compounds. For example, hindered phenols include “Sumilizer BHT-R”, “Sumilizer MDP-S”, “Sumilizer BBM-S”, “Sumizer WX-R”, “Sumizer NW”, “Sumizer BP-76”, “ Sumilizer BP-101 "," Sumilizer GA-80 "," Sumilizer GM "," Sumilizer GS "or more manufactured by Sumitomo Chemical Co., Ltd.," IRGANOX1010 "," IRGANOX1035 "," IRGANOX1076 "," IRGANOX1098 "," IRGANOX1098 "," 114 " ”,“ IRGANOX1222 ”,“ IRGANOX1330 ”,“ IRGANOX1425WL ”,“ IRGANOX1 20L "," IRGANOX 245 "," IRGANOX 259 "," IRGANOX 3114 "," IRGANOX 3790 "," IRGANOX 5057 "," IRGANOX 565 "or more, manufactured by Ciba Specialty Chemicals," ADK STAB AO-20 "," ADK STAB AO-30 "," ADEKA STAB " "AO-40", "ADK STAB AO-50", "ADK STAB AO-60", "ADK STAB AO-70", "ADK STAB AO-80", "ADK STAB AO-330" or more manufactured by Asahi Denka. As the hindered amine system, “Sanol LS2626”, “Sanol LS765”, “Sanol LS770”, “Sanol LS744” or more manufactured by Sankyo Lifetech Co., Ltd., “Tinubin 144”, “Tinubin 622LD”, “Mark LA57”, “ “Mark LA67”, “Mark LA62”, “Mark LA68”, “Mark LA63”, “Smilizer TPS”, “Smilizer TP-D” for thioethers, “Mark 2112”, “Mark PEP” for phosphites -8 "," Mark PEP.24G "," Mark PEP.36 "," Mark 329K "," Mark HP.10 ", and hindered phenols and hindered amine antioxidants are particularly preferable. Furthermore, these may be modified with a substituent such as an alkoxysilyl group capable of undergoing a crosslinking reaction with the material forming the crosslinked film.

  For the protective layer, polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin Insulating resin such as polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin may be contained. In this case, the insulating resin can be added at a desired ratio, thereby suppressing adhesion with the charge transport layer, coating film defects due to heat shrinkage and repellency, and the like.

  The protective layer is formed by applying a protective layer-forming coating solution containing the above-described constituent materials onto the charge transport layer and curing it.

  Since the protective layer is formed using the above-described charge transport material, it is preferable to add a catalyst to the protective layer forming coating solution or to use the catalyst when preparing the protective layer forming coating solution. Catalysts used include inorganic acids such as hydrochloric acid, acetic acid, phosphoric acid and sulfuric acid, organic acids such as formic acid, propionic acid, oxalic acid, paratoluenesulfonic acid, benzoic acid, phthalic acid and maleic acid, potassium hydroxide, water An alkali catalyst such as sodium oxide, calcium hydroxide, ammonia, triethylamine, or a solid catalyst insoluble in the system can also be used.

  In addition, in order to remove the catalyst at the time of synthesis from a phenol derivative having a methylol group, the phenol derivative is dissolved in a suitable solvent such as methanol, ethanol, toluene, ethyl acetate, washed with water, reprecipitation using a poor solvent, etc. It is preferable to perform the above treatment or to perform treatment using an ion exchange resin or an inorganic solid.

  For example, as an ion exchange resin, Amberlite 15, Amberlite 200C, Amberlyst 15E (above, manufactured by Rohm and Haas); Dowex MWC-1-H, Dowex 88, Dowex HCR-W2 (above Levacit SPC-108, Levacit SPC-118 (above, Bayer); Diaion RCP-150H (Mitsubishi Kasei); Sumikaion KC-470, Duolite C26-C, Duolite C-433, Duolite-464 (above, manufactured by Sumitomo Chemical Co., Ltd.); Cation exchange resins such as Nafion-H (DuPont); Amberlite IRA-400, Amberlite IRA-45 (above, Rohm and Anion exchange resins such as (made by Haas) are listed.

Further, as the inorganic solid, an inorganic solid in which a group containing a protonic acid group such as Zr (O ₃ PCH ₂ CH ₂ SO ₃ H) ₂ or Th (O ₃ PCH ₂ CH ₂ COOH) ₂ is bonded to the surface. A polyorganosiloxane containing a protonic acid group such as a polyorganosiloxane having a sulfonic acid group; a heteropolyacid such as cobalt tungstic acid or phosphomolybdic acid; an isopolyacid such as niobic acid, tantalic acid or molybdic acid; silica gel, alumina, Single metal oxides such as chromia, zirconia, CaO, MgO; complex metal oxides such as silica-alumina, silica-magnesia, silica-zirconia, zeolites; clay minerals such as acid clay, activated clay, montmorillonite, and kaolinite Metal sulfates such as LiSO ₄ and MgSO ₄ ; gold such as zirconia phosphate and lanthanum phosphate Metal nitrate; LiNO ₃ , metal nitrate such as Mn (NO ₃ ) ₂ ; Group containing amino group such as solid obtained by reacting aminopropyltriethoxysilane on silica gel is bonded to the surface Inorganic solids: Polyorganosiloxanes containing amino groups such as amino-modified silicone resins.

  For the coating liquid for forming the protective layer, alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone and methyl ethyl ketone; tetrahydrofuran; ethers such as diethyl ether and dioxane; Can be used. In order to apply the dip coating method generally used for the production of the photoreceptor, an alcohol solvent, a ketone solvent, or a mixed solvent thereof is preferable. In addition, the boiling point of the solvent used is preferably 50 to 150 ° C., and these can be arbitrarily mixed and used.

  In addition, since an alcohol solvent, a ketone solvent, or a mixed solvent thereof is preferable as the solvent, the charge transport material used for forming the protective layer to be used may be soluble in these solvents. preferable.

  The amount of the solvent can be set arbitrarily, but if the amount is too small, the constituent materials are likely to be precipitated. Therefore, the amount of the solvent is preferably 0.5 to 30 mass with respect to the total 1 mass part of the solid content contained in the coating liquid for forming the protective layer. Part, more preferably 1 to 20 parts by mass.

  Coating methods for forming a protective layer using a coating solution for forming a protective layer include blade coating, wire bar coating, spray coating, dip coating, bead coating, air knife coating, and curtain coating. A usual method such as can be used. However, when a required film thickness cannot be obtained by a single application, the necessary film thickness can be obtained by applying a plurality of times. In addition, when performing the multiple application | coating several times, a heat processing may be performed every time of application | coating, and may be after carrying out multiple application | coating several times.

  After applying the coating liquid for forming the protective layer on the charge transport layer, a curing process is performed. Usually, during the curing treatment, the curing temperature is higher and the curing time is longer in order to promote the crosslinking reaction of the phenol derivative and increase the mechanical strength of the protective layer. However, in such a case, the absorbance ratio (P2 / P1) tends to exceed 0.2, and the electrical characteristics are significantly deteriorated. Therefore, it is preferable to control with a curing temperature, a curing time, a crosslinking atmosphere or a curing catalyst so that the IR spectrum of the protective layer satisfies the above conditions.

That is, in order for the IR spectrum of the protective layer to satisfy the condition represented by the above formula, the curing temperature during the curing treatment is preferably 100 to 170 ° C, more preferably 100 to 150 ° C, and more preferably 100 to 140 ° C. Further preferred. The curing time is preferably 30 minutes to 2 hours, more preferably 30 minutes to 1 hour.
Further, as an atmosphere for performing the curing treatment (crosslinking reaction), the absorbance ratio (P2 / P1) is reduced under a so-called oxidation inert gas atmosphere (inert gas atmosphere) such as nitrogen, helium, and argon. It is effective. When the crosslinking reaction is performed in an inert gas atmosphere, the curing temperature can be set higher than in an air atmosphere (oxygen-containing atmosphere), and the curing temperature is 100 to 160 ° C. (preferably 110 to 150 ° C.). Is possible. The curing time can be 30 minutes to 2 hours (preferably 30 minutes to 1 hour). In addition, in the compound represented by the general formula (I), when the site represented by (— (X ¹ ) _m1 — (R ¹ ) _m2 —Y) is —CH ₂ —OH, the influence of the electrical characteristics due to the curing temperature is the highest. Is apt to be large and is sensitive to oxidation. Therefore, it is preferable to carry out the curing treatment in the above preferred temperature range.

  Furthermore, it is preferable to use a curing catalyst during the curing treatment. Examples of the curing catalyst include bissulfonyldiazomethanes such as bis (isopropylsulfonyl) diazomethane, bissulfonylmethanes such as methylsulfonyl p-toluenesulfonylmethane, and sulfonylcarbonyldiazomethanes such as cyclohexylsulfonylcyclohexylcarbonyldiazomethane, 2 -Sulfonylcarbonyl alkanes such as methyl-2- (4-methylphenylsulfonyl) propiophenone, nitrobenzyl sulfonates such as 2-nitrobenzyl p-toluenesulfonate, alkyl and aryl sulfonates such as pyrogallol trismethanesulfonate Benzoin sulfonates such as benzoin tosylate, such as N- (trifluoromethylsulfonyloxy) phthalimide -Sulfonyloxyimides, pyridones such as (4-fluorobenzenesulfonyloxy) -3,4,6-trimethyl-2-pyridone, 2,2,2-trifluoro-1-trifluoromethyl-1- ( Photoacid generators such as sulfonic acid esters such as 3-vinylphenyl) -ethyl-4-chlorobenzenesulfonate, onium salts such as triphenylsulfonium methanesulfonate, diphenyliodonium trifluoromethanesulfonate, protonic acids or Lewis acids. Examples thereof include compounds neutralized with a Lewis base, mixtures of Lewis acids and trialkyl phosphates, sulfonate esters, phosphate esters, onium compounds, and carboxylic anhydride compounds.

Compounds obtained by neutralizing a protonic acid or Lewis acid with a Lewis base include halogenocarboxylic acids, sulfonic acids, sulfuric acid monoesters, phosphoric acid mono- and diesters, polyphosphoric acid esters, boric acid mono- and diesters, and the like. Various amines such as monoethylamine, triethylamine, pyridine, piperidine, aniline, morpholine, cyclohexylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, or trialkylphosphine, triarylphosphine, trialkylphosphite, triaryl Compounds neutralized with phosphite, as well as NureCure 2500X, 4167, X-47-110, 3525, 5225 commercially available as acid-base blocking catalysts (trade name, King Ndasutori Co., Ltd.), and the like. Examples of the compound obtained by neutralizing a Lewis acid with a Lewis base include compounds obtained by neutralizing a Lewis acid such as BF ₃ , FeCl ₃ , SnCl ₄ , AlCl ₃ , ZnCl ₂ with the above Lewis base.

  Examples of the onium compound include triphenylsulfonium methanesulfonate, diphenyliodonium trifluoromethanesulfonate, and the like.

Examples of the carboxylic anhydride compound include acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, lauric anhydride, oleic anhydride, stearic anhydride, n-caproic anhydride, n-caprylic anhydride, and n-capric anhydride. , Palmitic anhydride, myristic anhydride, trichloroacetic anhydride, dichloroacetic anhydride, monochloroacetic anhydride, trifluoroacetic anhydride, heptafluorobutyric anhydride, and the like.
Specific examples of Lewis acids include, for example, boron trifluoride, aluminum trichloride, titanium chloride, ferric chloride, ferrous chloride, ferric chloride, zinc chloride, zinc bromide, stannous chloride. , Metal halides such as stannic chloride, stannous bromide, stannic bromide, organometallic compounds such as trialkylboron, trialkylaluminum, dialkylaluminum halide, monoalkylaluminum halide, tetraalkyltin , Diisopropoxyethyl acetoacetate aluminum, tris (ethyl acetoacetate) aluminum, tris (acetylacetonato) aluminum, diisopropoxy bis (ethyl acetoacetate) titanium, diisopropoxy bis (acetylacetonato) titanium, tetrakis (N-propylacetoacetate Zirconium, Tetrakis (acetylacetonato) zirconium, Tetrakis (ethylacetoacetate) zirconium, Dibutyl-bis (acetylacetonato) tin, Tris (acetylacetonato) iron, Tris (acetylacetonato) rhodium, Bis (acetyl) Acetonato) zinc, tris (acetylacetonato) cobalt metal chelate compounds, dibutyltin dilaurate, dioctyltin ester malate, magnesium naphthenate, calcium naphthenate, manganese naphthenate, iron naphthenate, cobalt naphthenate, copper naphthenate , Zinc naphthenate, zirconium naphthenate, lead naphthenate, calcium octylate, manganese octylate, iron octylate, cobalt octylate, zinc octylate, zirconium octylate, Tin chill acid, lead octylate, zinc laurate, magnesium stearate, aluminum stearate, calcium stearate, cobalt stearate, zinc stearate, and metal soaps such as stearate lead. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Although the usage-amount of these curing catalysts is not specifically limited, 0.1-20 mass parts is preferable with respect to a total of 100 mass parts of solid content contained in the coating liquid for protective layer formation, and 0.3-10 mass parts is especially preferable. preferable.

When an organic metal compound is used as a catalyst when forming the protective layer, it is preferable to add a polydentate ligand from the viewpoint of pot life and curing efficiency. Examples of such multidentate ligands include, but are not limited to, those shown below and those derived therefrom.
Specifically, β-diketones such as acetylacetone, trifluoroacetylacetone, hexafluoroacetylacetone, and dipivaloylmethylacetone; acetoacetates such as methyl acetoacetate and ethyl acetoacetate; bipyridine and derivatives thereof; glycine and its Derivatives; ethylenediamine and derivatives thereof; 8-oxyquinoline and derivatives thereof; salicylaldehyde and derivatives thereof; catechol and derivatives thereof; bidentate ligands such as 2-oxyazo compounds; diethyltriamine and derivatives thereof; nitrilotriacetic acid and derivatives thereof And tridentate ligands such as ethylenediaminetetraacetic acid (EDTA) and derivatives thereof. In addition to the organic ligands as described above, inorganic ligands such as pyrophosphoric acid and triphosphoric acid can be exemplified. As the multidentate ligand, a bidentate ligand is particularly preferable, and specific examples include a bidentate ligand represented by the following general formula (VII-4) in addition to the above.

In the formula (VII-4), R ³² and R ³³ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorinated alkyl group, or an alkoxy group having 1 to 10 carbon atoms.

Among the above, as the multidentate ligand, a bidentate ligand represented by the general formula (VII-4) is more preferable, and R ³² and R ^{33 in} the general formula (VII-4) are the same. Is particularly preferred. By making R ³² and R ^{33 the} same, the coordination power of the ligand near room temperature becomes strong, and the coating liquid for forming the protective layer can be further stabilized.

  The compounding amount of the polydentate ligand can be arbitrarily set, but is preferably 0.01 mol or more, more preferably 0.1 mol or more, and still more preferably with respect to 1 mol of the organometallic compound used. 1 mole or more.

Oxygen permeability at 25 ° C. of the protective layer is preferably not more than ^{4 × 10 12 fm / s ·} Pa, more preferably not more than ^{3.5 × 10 12 fm / s ·} Pa, 3 × 10 12 More preferably, it is fm / s · Pa or less.
Here, the oxygen permeation coefficient is a scale representing the ease of oxygen gas permeation of the layer, but it can also be regarded as a substitute characteristic of the physical gap ratio of the layer if the view is changed. In addition, although the absolute value of the transmittance changes if the type of gas changes, there is almost no reversal of the magnitude relationship between the layers serving as specimens. Therefore, the oxygen permeation coefficient may be interpreted as a measure expressing the general ease of gas permeation.
That is, when the oxygen permeation coefficient at 25 ° C. of the protective layer satisfies the above conditions, gas hardly penetrates into the protective layer. Therefore, the penetration of the discharge product generated by the image forming process is suppressed, the deterioration of the compound contained in the protective layer is suppressed, the electrical characteristics can be maintained at a high level, and it is effective for high image quality and long life. It is.

When the protective layer is to be formed so that the absorbance ratio (P2 / P1) of the infrared absorption spectrum satisfies the above conditions, it is necessary to set the curing temperature relatively low in an air atmosphere. Therefore, it is difficult to lower the oxygen transmission coefficient at 25 ° C. of the protective layer, but the absorbance ratio (P2 / P1) satisfies the above condition, and the oxygen transmission coefficient at 25 ° C. of the protective layer satisfies the above condition. By satisfying these conditions, a photoreceptor that can further improve electrical characteristics and achieve higher image quality can be obtained.
The thickness of the protective layer is preferably 0.5 to 15 μm, more preferably 1 to 10 μm, and more preferably 1 to 5 μm.

Next, the toner used in the present invention will be described. The toner used in the present invention is not particularly limited by the production method. For example, (1) kneading in which a binder resin, a colorant, a release agent, and a charge control agent as necessary are kneaded, pulverized, and classified. Pulverization method, (2) a method of changing the shape of particles obtained by kneading pulverization method by mechanical impact force or thermal energy, and (3) emulsion polymerization of a binder resin polymerizable monomer. An emulsion polymerization aggregation method in which toner particles are obtained by mixing the dispersion liquid and a dispersion liquid such as a colorant, a release agent and, if necessary, a charge control agent, and aggregating and heat-fusing, (4) binder resin A suspension polymerization method in which a polymerizable monomer and a colorant, a release agent, and, if necessary, a solution such as a charge control agent are suspended in an aqueous solvent for polymerization, and (5) a binder resin and a color For example, a dissolution suspension method in which a solution of an agent, a release agent, and a charge control agent, if necessary, is suspended in an aqueous solvent and granulated Ri resulting materials can be used.
In addition, a known method such as a production method in which the toner obtained by the above method is used as a core, and agglomerated particles are further adhered and heat-fused to give a core-shell structure can be used, but from the viewpoint of shape control and particle size distribution control Suspension polymerization method, emulsion polymerization aggregation method, and dissolution suspension method, which are produced from an aqueous solvent, are preferred, and emulsion polymerization aggregation method is particularly preferred.

The toner particles include a binder resin, a colorant, a release agent, and the like. If necessary, silica or a charge control agent may be used. The volume average particle size of the toner is preferably in the range of 2 to 12 μm, and more preferably in the range of 3 to 9 μm. Further, by using a toner having an average shape index (ML ² / A: ML is the absolute maximum length of toner particles, and A is the projected area of the toner particles) in the range of 100 to 145, high development and transfer And high-quality images can be obtained. More preferably, it is 125-140.
By using a toner having an average shape index of 125 to 140, it is possible to obtain a high-quality transfer image and to suppress the deterioration of the adhesion of the toner or the external additive to the contact charging member due to poor cleaning. .

  Binder resins used include styrenes such as styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene, and isoprene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate; Α-methylene aliphatic monocarboxylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Examples of vinyl polymers such as vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropenyl ketone; Particularly typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene- Mention may be made of maleic anhydride copolymers, polyethylene, polypropylene and the like. Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like.

  In addition, toner colorants include magnetic powders such as magnetite and ferrite, carbon black, aniline blue, caryl blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, and malachite green oxa. Rate, lamp black, rose bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 can be exemplified as a representative one.

  Typical examples of the release agent include low molecular polyethylene, low molecular polypropylene, Fischer-Tropsch wax, montan wax, carnauba wax, rice wax, and candelilla wax.

  In addition, a charge control agent may be added to the toner as necessary. Known charge control agents can be used, but azo metal complex compounds, metal complex compounds of salicylic acid, and resin type charge control agents containing polar groups can be used. When the toner is manufactured by a wet manufacturing method, it is preferable to use a material that is difficult to dissolve in water in terms of controlling ionic strength and reducing wastewater contamination. The toner in the present invention may be either a magnetic toner containing a magnetic material or a non-magnetic toner containing no magnetic material.

As the inorganic oxide added as an external additive to the toner, a small-diameter inorganic oxide having a primary particle size of 40 nm or less is used for powder flowability, charge control, etc. A larger-diameter inorganic oxide can be mentioned. Although these inorganic oxide fine particles can use a well-known thing, the following things can be illustrated.
For example, silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate, magnesium titanate, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, manganese oxide, Various inorganic oxides such as boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, boron nitride, calcium carbonate, calcium carbonate, magnesium carbonate and calcium phosphate, nitrides, borides and the like are preferably used. Is done.
Moreover, titanium coupling agents such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzene sulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, γ- (2-amino) Ethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxysilane Hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane The treatment may be performed with a silane coupling agent such as run, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, and p-methylphenyltrimethoxysilane. Further, hydrophobic treatment with a higher fatty acid metal salt such as silicone oil, aluminum stearate, zinc stearate, calcium stearate can be preferably performed.

The toner in the present invention can be produced by mixing the toner particles and the external additive with a Henschel mixer or a V blender. In addition, when the toner particles are produced by a wet method, external addition can be performed by a wet method.
In addition, when the toner in the present invention is used as a color toner, it is preferably used by mixing with a carrier. Examples of the carrier include iron powder, glass beads, ferrite powder, nickel powder, or the surface thereof. A resin coating is used.
Further, the mixing ratio of the carrier and the toner can be set as appropriate.

EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited by the following Example.
[Cleaning device]
As the first and second cleaning units in FIG. 2, the following ones were used, and cleaning devices 1 to 4 (both are process cartridges) were produced. For comparison, a cleaning blade was used as the cleaning device 5. In addition, the surface of the cleaning brush which concerns on the cleaning apparatuses 1, 2, and 4 was made into the spiral shape shown in FIG.3 (C). Further, the surface of the cleaning brush according to the cleaning device 3 was covered with one kind of brush hair. In the following examples, the base fabric width refers to the width of region A or region B in FIG.

(Cleaning device 1)
<First cleaning unit>
-Cleaning brush-
Material of region A: conductive nylon, fiber thickness: 2 denier, electric resistance: 1 × 10 ⁵ Ω, hair leg length: 4 mm, fiber density: 120,000 pieces / inch ² , base fabric width 20 mm,
Material of region B: conductive nylon, fiber thickness: 6 denier, electrical resistance: 1 × 10 ⁵ Ω, hair leg length: 4 mm, fiber density: 50,000 fibers / inch ² , base fabric width 4 mm,
The amount of biting into the photoconductor: 1.5 mm, peripheral speed: 60 mm / s, rotation direction: reverse rotation with respect to the rotation direction of the photoconductor, and brush application bias: + 200V.
-Recovery roll member-
Material: phenol resin in which conductive carbon is dispersed, electric resistance: 1 × 10 ⁶ Ω, flexural modulus (JIS K7203): 100 MPa, wear amount (JIS K6902): 2 mg, Rockwell hardness (JIS K7202, M scale): 120, the amount of biting into the brush member: 1.5 mm, peripheral speed: 70 mm / s, applied bias: + 600V.
-Scraper-
Material: SUS304, thickness: 80 μm, amount of biting into the recovery roll member: 1.3 mm, free length (free length): 8.0 mm.

<Second cleaning unit>
-Cleaning brush-
Material of region A: conductive nylon, fiber thickness: 2 denier, electric resistance: 1 × 10 ⁵ Ω, hair leg length: 4 mm, fiber density: 120,000 pieces / inch ² , base fabric width 20 mm,
Material of region B: conductive nylon, fiber thickness: 6 denier, electrical resistance: 1 × 10 ⁵ Ω, hair leg length: 4 mm, fiber density: 50,000 fibers / inch ² , base fabric width 4 mm,
The amount of biting into the photoconductor: 1.5 mm, peripheral speed: 60 mm / s, rotation direction: reverse rotation with respect to the rotation direction of the photoconductor, and brush application bias: −400V.
-Recovery roll member-
Material: phenol resin in which conductive carbon is dispersed, electric resistance: 1 × 10 ⁶ Ω, flexural modulus (JIS K7203): 100 MPa, wear amount (JIS K6902): 2 mg, Rockwell hardness (JIS K7202, M scale): 120, the amount of biting into the brush member: 1.5 mm, the peripheral speed: 70 mm / s, and the applied bias: -800V.
<Scraper>
Material: SUS304, thickness: 80 μm, amount of biting into the recovery roll member: 1.3 mm, free length (free length): 8.0 mm.

(Cleaning device 2)
<First cleaning unit>
-Cleaning brush-
Material of region A: conductive nylon, fiber thickness: 5 denier, electric resistance: 1 × 10 ⁵ Ω, hair leg length: 4 mm, fiber density: 150,000 / inch ² , base fabric width 30 mm,
Material of region B: conductive nylon, fiber thickness: 10 denier, electric resistance: 1 × 10 ⁵ Ω, hair leg length: 4 mm, fiber density: 50,000 fibers / inch ² , base fabric width 4 mm,
The amount of biting into the photoconductor: 1.0 mm, peripheral speed: 60 mm / s, rotation direction: reverse rotation with respect to the rotation direction of the photoconductor, and brush application bias: + 200V.
-Recovery roll member-
Material: phenol resin in which conductive carbon is dispersed, electric resistance: 1 × 10 ⁶ Ω, flexural modulus (JIS K7203): 100 MPa, wear amount (JIS K6902): 2 mg, Rockwell hardness (JIS K7202, M scale): 120, the amount of biting into the brush member: 1.5 mm, peripheral speed: 70 mm / s, applied bias: + 600V.
-Scraper-
Material: SUS304, thickness: 80 μm, amount of biting into the recovery roll member: 1.3 mm, free length (free length): 8.0 mm.

<Second cleaning unit>
-Cleaning brush-
Material of region A: conductive nylon, fiber thickness: 5 denier, electric resistance: 1 × 10 ⁵ Ω, hair leg length: 4 mm, fiber density: 150,000 / inch ² , base fabric width 30 mm,
Material of region B: conductive nylon, fiber thickness: 10 denier, electric resistance: 1 × 10 ⁵ Ω, hair leg length: 4 mm, fiber density: 50,000 fibers / inch ² , base fabric width 4 mm,
The amount of biting into the photoconductor: 1.0 mm, peripheral speed: 60 mm / s, rotation direction: reverse rotation with respect to the rotation direction of the photoconductor, and brush application bias: −400V.
-Recovery roll member-
Material: phenol resin in which conductive carbon is dispersed, electric resistance: 1 × 10 ⁶ Ω, flexural modulus (JIS K7203): 100 MPa, wear amount (JIS K6902): 2 mg, Rockwell hardness (JIS K7202, M scale): 120, the amount of biting into the brush by the member: 1.5 mm, the peripheral speed: 70 mm / s, and the applied bias: -800V.
-Scraper-
Material: SUS304, thickness: 80 μm, amount of biting into the recovery roll member: 1.3 mm, free length (free length): 8.0 mm.

(Cleaning device 3)
<First cleaning unit>
-Cleaning brush-
A brush is made of conductive nylon, fiber thickness: 2 denier, electrical resistance: 1 × 10 ⁵ Ω, hair length: 4 mm, fiber density: 150,000 / inch ² , and the amount of biting into the photoreceptor : 1.0 mm, peripheral speed: 60 mm / s, rotation direction: reverse rotation with respect to the rotation direction of the photoconductor, brush application bias: + 200V.
-Recovery roll member-
Material: phenol resin in which conductive carbon is dispersed, electric resistance: 1 × 10 ⁸ Ω, flexural modulus (JIS K7203): 100 MPa, wear amount (JIS K6902): 2 mg, Rockwell hardness (JIS K7202, M scale): 120, the amount of biting into the brush member: 1.5 mm, peripheral speed: 70 mm / s, applied bias: + 600V.
-Scraper-
Material: SUS304, thickness: 80 μm, amount of biting into the recovery roll member: 1.3 mm, free length (free length): 8.0 mm.

<Second cleaning unit>
-Cleaning brush-
Conductive nylon, fiber thickness: 2 denier, electrical resistance: 1 × 10 ⁵ Ω, bristle length: 4 mm, fiber density: 150,000 fibers / inch ² , and the amount of biting into the photoreceptor: 1.0 mm, peripheral speed: 60 mm / s, rotation direction: reverse rotation with respect to the rotation direction of the photoreceptor, and brush application bias: -400V.
-Recovery roll member-
Material: phenol resin in which conductive carbon is dispersed, electric resistance: 1 × 10 ⁸ Ω, flexural modulus (JIS K7203): 100 MPa, wear amount (JIS K6902): 2 mg, Rockwell hardness (JIS K7202, M scale): 120, the amount of biting into the brush member: 1.5 mm, the peripheral speed: 70 mm / s, and the applied bias: -800V.
-Scraper-
Material: SUS304, thickness: 80 μm, amount of biting into the recovery roll member: 1.3 mm, free length (free length): 8.0 mm.

(Cleaning device 4)
<First cleaning unit>
-Cleaning brush-
Material of region A: conductive nylon, fiber thickness: 2 denier, electric resistance: 1 × 10 ⁵ Ω, hair leg length: 4 mm, fiber density: 120,000 pieces / inch ² , base fabric width 4 mm,
Material of region B: conductive nylon, fiber thickness: 6 denier, electric resistance: 1 × 10 ⁵ Ω, hair leg length: 4 mm, fiber density: 80,000 pieces / inch ² , base fabric width 20 mm,
The amount of biting into the photoconductor: 1.5 mm, peripheral speed: 60 mm / s, rotation direction: reverse rotation with respect to the rotation direction of the photoconductor, and brush application bias: + 200V.
-Recovery roll member-
Material: phenol resin in which conductive carbon is dispersed, electric resistance: 1 × 10 ⁶ Ω, flexural modulus (JIS K7203): 100 MPa, wear amount (JIS K6902): 2 mg, Rockwell hardness (JIS K7202, M scale): 120, the amount of biting into the brush member: 1.5 mm, peripheral speed: 70 mm / s, applied bias: + 600V.
-Scraper-
Material: SUS304, thickness: 80 μm, amount of biting into the recovery roll member: 1.3 mm, free length (free length): 8.0 mm.

<Second cleaning unit>
-Cleaning brush-
Material of region A: conductive nylon, fiber thickness: 2 denier, electric resistance: 1 × 10 ⁵ Ω, hair leg length: 4 mm, fiber density: 120,000 pieces / inch ² , base fabric width 4 mm,
Material of region B: conductive nylon, fiber thickness: 6 denier, electric resistance: 1 × 10 ⁵ Ω, hair leg length: 4 mm, fiber density: 80,000 pieces / inch ² , base fabric width 20 mm,
The amount of biting into the photoconductor: 1.5 mm, peripheral speed: 60 mm / s, rotation direction: reverse rotation with respect to the rotation direction of the photoconductor, and brush application bias: −400V.
-Recovery roll member-
Material: phenol resin in which conductive carbon is dispersed, electric resistance: 1 × 10 ⁶ Ω, flexural modulus (JIS K7203): 100 MPa, wear amount (JIS K6902): 2 mg, Rockwell hardness (JIS K7202, M scale): 120, the amount of biting into the brush member: 1.5 mm, the peripheral speed: 70 mm / s, and the applied bias: -800V.
<Scraper>
Material: SUS304, thickness: 80 μm, amount of biting into the recovery roll member: 1.3 mm, free length (free length): 8.0 mm.

(Cleaning device 5)
Blade material: urethane rubber, thickness: 2 mm, amount of biting into the photoreceptor: 1.1 mm, free length (free length): 10 mm, arrangement direction: doctor direction with a biting angle of 23 degrees with respect to the photoreceptor.

[Photoconductor]
<Photoreceptor 1>
To 170 parts by mass of n-butyl alcohol in which 4 parts by mass of polyvinyl butyral resin (ESREC BM-S, manufactured by Sekisui Chemical Co., Ltd.) was dissolved, 30 parts by mass of an organic zirconium compound (acetylacetone zirconium butyrate) and an organic silane compound (γ-amino) 3 parts by mass of propyltrimethoxysilane) was added, mixed and stirred to obtain a coating solution for forming an undercoat layer. This coating solution is dip-coated on an aluminum support having an outer diameter of 40 mm roughened by a honing treatment, air-dried at room temperature for 5 minutes, and then the support is heated to 50 ° C. for 10 minutes, It was placed in a constant temperature and humidity chamber at 50 ° C. and 85% RH (dew point 47 ° C.), and a humidification hardening acceleration treatment was performed for 20 minutes. Then, it put in the hot air dryer and dried for 10 minutes at 170 degreeC, and formed the undercoat layer.
As a charge generation material, a mixture of 15 parts by mass of gallium chloride phthalocyanine, 10 parts by mass of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Union Carbide) and 300 parts by mass of n-butyl alcohol was used in a sand mill for 4 hours. Distributed. The obtained dispersion was dip-coated on the undercoat layer and dried to form a charge generation layer having a thickness of 0.2 μm. Next, 40 parts by weight of N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine and 60 parts by weight of bisphenol Z polycarbonate resin (molecular weight 40,000) were added to 235 parts by weight of tetrohydrofuran and monochlorobenzene. A coating solution obtained by sufficiently dissolving and mixing in 100 parts by mass was dip-coated on the charge generation layer and dried at 120 ° for 40 minutes to form a charge transport layer having a thickness of 24 μm. This was designated as photoreceptor 1.

<Photoreceptor 2>
5 parts by mass of the following compound 1, 15 parts by mass of isopropyl alcohol, 9 parts by mass of tetrahydrofuran, and 0.9 parts by mass of distilled water were mixed, and 0.5 parts by mass of ion exchange resin (Amberlyst 15E) was added thereto. The hydrolysis was carried out for 2 hours by stirring at room temperature. Furthermore, 0.5 parts by mass of butyral resin, 5 parts by mass of resol type phenol resin (PL-2211, manufactured by Gunei Chemical Co., Ltd.), 0.2 parts by mass of Sanol LS2626 (manufactured by Sankyo Lifetech) as a light stabilizer, Then, 0.5 parts by mass of Neicure 4167 (manufactured by Enomoto Kasei) was added as a catalyst to prepare a coating solution for forming a protective layer. This protective layer-forming coating solution is dip-coated on a charge transport layer prepared under the same conditions as the photoreceptor 1 except that the charge transport layer has a thickness of 22 μm, dried at 140 ° C. for 40 minutes, and has a thickness of 3 μm. A protective layer was formed. The obtained photoreceptor was designated as photoreceptor 2.

(Examples 1-3 and Comparative Examples 1-3)
An image forming apparatus (Fuji Xerox Co., Ltd., Docu Color 1250 modified machine) was manufactured by combining the photosensitive member and the cleaning device as shown in Table 1. A developer for Docu Color 1250 was used as the developer.
Durability tests of 100,000 sheets were performed under conditions of high temperature and high humidity (28 ° C, 80%) and low temperature and low humidity (10 ° C, 20% RH), and image flow, filming, photoconductor scratches, cleaning properties and overall evaluation were as follows. Evaluation was based on criteria. The results are shown in Table 1.

(Image flow)
A halftone image with an image density of 20% was collected after power-on in a high temperature and high humidity environment, and sensory evaluation was performed.
○: No white spots occur in the image stream ×: White spots occur in the image stream (photoconductor filming)
The printed image and the photoreceptor surface during running were observed.
○: No adhesion on the surface of the photoconductor ×: Adhesion on the surface of the photoconductor, streak density difference in the printed image (photoconductor scratches)
The streaks in the printed image and the photoreceptor surface during running were observed.
○: No streak density difference in the printed image ×: There is a scratch in the circumferential direction of the photoconductor, and a streak density difference occurs in the printed image (cleaning property)
The evaluation was performed by cleaning the presence or absence of a poorly-cleaned image in the printed image while running under low temperature and low humidity, and periodically cleaning an untransferred A3-sized image density 100% image. Judgment criteria are as follows.
○: No cleaning failure occurred in the printed image and untransferred image ×: Cleaning failure occurred in the printed image (overall evaluation)
Comprehensive evaluation was performed based on the following criteria.
○: Image flow, filming, scratches are not generated and toner cleaning property is maintained ×: Image flow, filming, scratches, toner cleaning property is insufficient

  From Table 1, it can be seen that the construction of the present invention can achieve a long life and high reliability of the photoreceptor and the cleaner.

1 is a schematic configuration diagram according to an embodiment of an image forming apparatus of the present invention. It is a schematic block diagram of the cleaning apparatus which concerns on this invention. It is a schematic diagram which shows the cleaning brush which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging device 3 Exposure device 4 Developing device 5 Transfer device 6 Fixing device 7 Cleaning device 700 Housing 701 Cleaning brush 702 Recovery roll member 703 Scraper 704, 705 Shaft 706 Mounting bracket P Transfer object

Claims (1)

A photosensitive member; a charging unit that uniformly charges the photosensitive member; a latent image forming unit that forms a latent image on the surface of the charged photosensitive member; and a latent image formed on the surface of the photosensitive member at least as a toner. Developing means for developing with a developer containing toner, transfer means for transferring the toner image formed on the surface of the photosensitive member to the transfer target, and toner image transferred to the transfer target An image forming apparatus comprising at least a fixing unit that fixes toner and a cleaning unit that removes residual toner on the surface of the photoreceptor after transfer,
The outermost surface layer of the photoreceptor is a protective layer,
The cleaning means includes at least a cleaning brush that rotates while bringing the bristles provided on the surface into contact with the surface of the photoreceptor, and the brush bristles are arranged on the surface of the cleaning brush along the rotation direction of the cleaning brush. An image forming apparatus having at least two regions having different thicknesses.

Images