JP5444732B2 - Electrophotographic photosensitive member, image forming apparatus, and process cartridge for image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member, and particularly suppresses the generation of abnormal images such as afterimages and interference fringes when used repeatedly, and has excellent environmental stability and electrical characteristics that are stable over the long term. The present invention relates to an electrophotographic photosensitive member obtained, an image forming apparatus using the electrophotographic photosensitive member, and a process cartridge for the image forming apparatus.

  An electrophotographic system using an electrophotographic photosensitive member applied to a copying machine, a laser printer, a facsimile, etc. is a method in which the surface of an electrophotographic photosensitive member (hereinafter also referred to as a photosensitive member) is charged in a dark place by corona discharge or the like. Then, the image is exposed to form an electrostatic latent image on the photoreceptor, and the electrostatic latent image is visualized with a developer in the developing unit, and the visible image is transferred and fixed to a transfer material to form an image. Form. The developer remaining on the photoconductor after the transfer is removed from the photoconductor through various cleaning processes, and an electrostatic latent image is formed on the photoconductor again.

  Conventionally, various inorganic and organic photoconductors are known as photoconductors for electrophotographic photoreceptors used in electrophotography, but in general, organic photoreceptors using organic photoconductors are selenium, oxidized. Compared to inorganic photoconductors such as zinc and cadmium sulfide, it has advantages in terms of freedom of photosensitive wavelength range, film formability, flexibility, film transparency, mass productivity, toxicity, cost, etc. Photoconductors are the mainstream.

  In recent years, expectations for higher durability of electrophotographic photoreceptors have increased, and of course, it has excellent durability and high quality images as well as having sensitivity, electrical characteristics, and optical characteristics according to the applied electrophotographic process. Maintaining for a long time is an important technical issue. Furthermore, it is also an important factor that the characteristics are sufficiently exhibited in any environment from low temperature and low humidity to high temperature and high humidity, and that no image defect occurs.

The organic photoreceptor is composed of a conductive support and an organic photosensitive layer formed thereon. In many cases, the organic photosensitive layer is a function separation type composed of a charge generation layer and a charge transport layer. The shape of the conductive support is selected according to the configuration of the electrophotographic apparatus used such as a sheet or cylinder, but the manufacturing cost varies depending on the manufacturing method as well as the dimensional accuracy and shape stability.
For example, as an example of a cylindrical support, there are various types of ED reeds that are extruded and drawn, EI reeds that are subjected to ironing on the outer surface after extrusion, and DI pipes that are produced by squeezing and ironing. Since all of them are used and no surface cutting is required, the mass productivity is excellent and the cost can be reduced.

  However, the support manufactured through such extrusion and drawing processes has innumerable streak defects of about several to 10 μm in the processing direction. There is a problem that a uniform photosensitive layer is not formed on such a support, and the uneven portion becomes an electric leak or an insulating portion, and defects such as black spots and white spots are seen on the image. In response to such a problem, various methods have been devised to mechanically remove minute irregularities on the surface of the support.

  Cutting with a lathe using a diamond tool to reduce runout and achieve outer diameter accuracy is an effective way to completely remove the microprojections on the surface of the support, but the tool feed amount must be reduced. In addition, the processing time is long, and expensive diamond tools are required, so that productivity is low. Furthermore, it is difficult to meet the demand for higher accuracy for a material that deteriorates the dimensional accuracy of the shape, such as a thin-walled support.

In recent years, a method using a semiconductor laser that is inexpensive and easy to handle as an exposure light source has become the mainstream, but in general, an electrophotographic photosensitive member having a photosensitive layer formed on a conductive support is a laser beam. Is applied to an electrophotographic apparatus that performs line scanning, an interference fringe pattern may appear in the obtained image. This kind of interference fringe is caused by the fact that transmitted light that is not absorbed in the photosensitive layer causes multiple reflections of the laser beam in the photosensitive layer including the conductive support, and interferes with the incident light on the surface of the photosensitive layer. It is thought to be caused by
Therefore, in order to remove the fine protrusions on the surface of the support described above and prevent the occurrence of interference fringes, for example, a wet (liquid) honing process and a dry honing process have been devised.

  Wet (liquid) honing treatment is a method of suspending powdered granular abrasive (abrasive grains) in a liquid such as water and spraying the surface of the support at high speed to roughen the surface. It can be controlled by pressure, speed, amount of abrasive grains, concentration, type, shape, size, hardness, specific gravity, suspension temperature and the like. Similarly, the dry honing process is a method in which abrasive grains are sprayed onto the surface of the support with air at high speed to roughen the surface, and the surface roughness can be controlled in the same manner as the wet honing process. Examples of the abrasive grains used in the wet or dry honing treatment include particles such as silicon carbide, alumina, zirconia, stainless steel, iron, glass beads, and plastic shot.

  Thus, since the rough surface is formed by causing the abrasive grains to collide with the surface of the support to be processed, it is difficult to control the roughness. Furthermore, since the abrasive grains pierce and remain on the support surface, it is possible to completely remove the abrasive on the support surface even if the cylindrical support outer surface is washed and removed. Have difficulty. In addition, when a photosensitive layer is directly formed on such a support, stains on the surface of the support and unevenness in shape appear as film formation unevenness of the photosensitive layer as they are, and black on a white image in a reversal development system. Pots and white spots on black images in the forward development system occur.

  Therefore, when forming an electrophotographic photosensitive member, in addition to forming a photosensitive layer directly on a conductive support, in addition to covering defects on the support, protecting the support, and improving the coatability of the photosensitive layer, It is effective to provide an undercoat layer on a conductive support for protection of electrical breakdown of the photosensitive layer, improvement of charge injection property to the photosensitive layer, and the like. Regarding the repetitive stability and environmental stability of the photoreceptor, the portion depending not only on the photosensitive layer but also on the undercoat layer is extremely large.

  Therefore, conventionally, in the electrophotographic photosensitive member, the coating property of the photosensitive layer is improved between the conductive support and the photosensitive layer, the charge injection from the conductive support is prevented, the charging property is stabilized, In addition, an undercoat layer is formed for the purpose of not accumulating residual potential.

  As a material for forming such an undercoat layer, an undercoat layer formed from a cellulose resin, a nylon resin, a maleic acid resin, a polyvinyl alcohol resin, a polyamide resin, or the like has been proposed. Some of them are susceptible to environmental fluctuations that are thought to be caused by ionic impurities in the organic resin, resulting in characteristic deterioration under high temperature and high humidity and low temperature and low humidity, especially under low temperature and low humidity. In some cases, the residual potential increases due to the increase in the voltage. Thus, it has been proposed to use a crosslinkable resin for the undercoat layer (see, for example, Patent Document 1), but there is a problem that the residual potential increases during repeated use, resulting in durability of electrical characteristics. Was not enough.

  In order to solve this problem, technologies such as constituting the undercoat layer with a cured film made of a reaction product of an organometallic compound and a silane coupling agent, and optimizing the preferable degree of curing have been proposed. (For example, refer to Patent Documents 2 and 3). This inorganic cured film has the advantages that the electrical characteristics are stable even in an environment such as high temperature and high humidity and low temperature and low humidity, and the resistance value does not significantly increase the residual potential. However, since it is difficult to increase the thickness of these techniques, these techniques are easily affected by minute uneven portions existing on the surface of the support, and further, new techniques that did not occur in the conventional non-contact charging method using corona discharge. There is an image defect problem.

  In addition, the undercoat layer contains an organometallic compound treated with a silane coupling agent (see, for example, Patent Document 4), and contains metal oxide fine particles to which an acceptor compound is added (for example, Patent Document 5). See also). However, in these techniques, if the metal oxide and the unreacted acceptor compound remain, they are eluted during formation by coating the upper layer, and a uniform undercoat layer cannot be formed. Therefore, sufficient electron transport performance is obtained. In other words, there are problems such as deterioration in image quality and poor adhesion between the undercoat layer and the upper layer.

  Furthermore, recently, instead of a non-contact charging type charging device such as corotron, a roller is contacted or used to reduce the generation amount of ozone and NOx gas, to reduce the cost by eliminating the need for a high-voltage power supply, and to reduce the size of the charger. Charging methods for charging by placing them in close proximity have been studied and commercialized. In such a contact or proximity charging method using a roller, since the roller is always in contact with or close to the surface of the electrophotographic photosensitive member and charged, generation of gas such as ozone and NOx can be prevented. During operation of an electrophotographic apparatus, a dielectric breakdown is generated when a conductive foreign substance such as a foreign substance generated from a member constituting the apparatus or a carrier powder contacts or penetrates the photosensitive member. Yes. This is considered to be because the conductive path between the contact charging device and the photosensitive member support is formed by the conductive foreign matter, and the undercoat layer is made thin to suppress the increase in residual potential. The tendency becomes more prominent in the photoconductor on which is formed.

On the other hand, in an electrophotographic photosensitive member used in an apparatus using a contact or proximity charging method, in order to improve the residual potential rise and obtain stable electric characteristics while concealing defects in the conductive support. Various studies have been conducted.
For example, there are those in which metal oxide particles (conductive particles) are dispersed in a binder resin, and such an undercoat layer applies a coating liquid containing metal oxide particles and a binder resin onto a support. And formed by drying (see, for example, Patent Document 6). The undercoat layer in which the conductive particles are dispersed in this way needs to reduce the amount of resin in order to improve the electrostatic characteristics of the electrophotographic photosensitive member, that is, to suppress the increase in residual potential. However, when the resin in the undercoat layer decreases, the adhesiveness with the support deteriorates, and when a small-diameter drum that can be expected to be miniaturized by repeated use is used, particularly between the support and the undercoat layer. Peeling between them tends to occur.
In addition, in order to suppress the increase in the residual potential, thinning is also an effective means, but in the image forming apparatus having the contact charging means described above, there is a possibility that a discharge breakdown is likely to occur.

  On the other hand, scumming may occur due to a decrease in charging potential or the like. To suppress this scumming, it is effective to reduce the content of conductive particles. However, since the electrical resistance increases, the influence of repeated use is significant, and an increase in residual potential degrades image quality. Background stain is a phenomenon in which an infinite number of black spots are originally generated in a white background area where an image is not printed, and is mainly caused by charge injection from a conductive support.

  As described above, in addition to the interference fringe prevention function, the method of controlling the charge injection and the resistance adjusting function by containing conductive particles in the undercoat layer prevents the increase of the residual potential. Under the present circumstances, an undercoat layer having a good soiling effect and excellent environmental stability has not been obtained.

On the other hand, a technique for laminating an undercoat layer has been proposed.
That is, it has a function of forming a layer containing conductive particles on a conductive support such as aluminum and further preventing charge injection from the conductive support on the layer containing conductive particles. It has an undercoat layer having a two-layer structure in which a resin layer is formed (see, for example, Patent Document 7). According to this method, the layer containing the conductive fine powder is provided with a function of adjusting electric resistance as well as concealing defects such as irregularities and dirt on the surface of the conductive support layer, and the resin layer formed thereon is charged. An injection control function is provided.

  As another method, an anodized film is formed on a conductive support such as aluminum, and a resin layer having a function of preventing charge injection is further formed on the anodized film (for example, , See Patent Document 8). The anodic oxide coating is generally formed to a thickness of 5 to 6 μm, and it is known that the entire defective portion on the surface of the support is insulated with this thickness. In addition to the fact that a lot of energy is required, the anodized film is a porous film, requires a sealing treatment, the processing time is long, and the surface treatment cost is high. The problem of image degradation due to instability of electrical characteristics due to influence is inevitable.

  Further, as another method, organic resin particles having pores are contained in at least one of the two undercoat layers (see, for example, Patent Document 9). However, this method still does not solve the problems caused by charge carriers staying in the photoconductor, and does not provide a fundamental solution to an increase in the potential of the exposed portion, a decrease in sensitivity, and a ghost image. .

  In addition, the single-layer undercoat layer can simplify the manufacturing process of the photoreceptor and reduce the manufacturing cost compared to the laminated undercoat layer. It was necessary to have both functions of control, which had a great restriction on material design.

On the other hand, in an image forming apparatus using a contact or proximity charging method, it is likely to occur when there is a defective portion of the photoreceptor or when conductive foreign matter such as carrier powder contacts or penetrates the photoreceptor. In order to prevent discharge breakdown, a technique for thickening the undercoat layer has been proposed (see, for example, Patent Document 10).
This thickening is an effective means for preventing discharge breakdown, but since there is a concern about an increase in residual potential due to an increase in resistance, good electrical characteristics are obtained when the film is thickened. Therefore, it is necessary to reduce the resistance, but the blocking property against the charge injection from the conductive support is weakened, and the occurrence of scumming is increased.

Furthermore, in addition to the demand for higher speed, there is an increasing demand for downsizing of the image forming apparatus from the viewpoint of space saving. Usually, in an image forming apparatus using an electrophotographic photosensitive member, image forming means such as a charging unit, an image exposing unit, a developing unit, a fixing unit, and a cleaning unit are arranged around the electrophotographic photosensitive member. The size of the image forming apparatus largely depends on the diameter of the electrophotographic photosensitive member to be used. To reduce the size of the image forming apparatus, it is necessary to reduce the occupied volume of the electrophotographic photosensitive member.
Therefore, in the trend of shifting to a method of using a small-diameter electrophotographic photosensitive member at a high linear velocity, it is indispensable to increase the sensitivity of the electrophotographic photosensitive member.

  To increase the sensitivity of the electrophotographic photosensitive member, it is effective to use a charge generation material having a large quantum efficiency. The quantum efficiency here is expressed by the ratio of the number of charges on the surface of the photoreceptor neutralized by the movement of the carriers generated by the excitation of the light to the incident photon for exposing the photoreceptor. As charge generating materials having high sensitivity in the infrared region, phthalocyanine pigments such as oxytitanium phthalocyanine, hydroxygallium phthalocyanine, and chlorogallium phthalocyanine, and azo pigments such as monoazo, bisazo, and trisazo are known.

However, since the amount of charge generation for exposure has been significantly improved, electrons after holes are injected into the charge transport layer are likely to stay in the charge generation layer, and the rising of the surface potential during charging or ghost images ( The afterimage problem occurs.
Here, the ghost image appears because an exposed portion and an unexposed portion on the electrophotographic photosensitive member cause a difference in electrical characteristics in the next cycle, and the density of only the portion irradiated with light at the time of the previous rotation. There is a positive ghost image in which the image becomes dark, and on the contrary, a negative ghost image in which the concentration of only the portion irradiated with light at the time of the previous rotation becomes light.
Specifically, in an electrophotographic image forming apparatus, when a halftone image is output after outputting a clear and bright image, it is output before the halftone image in an image that should be a uniform image. This is a phenomenon in which an image pattern appears.
Thus, when a highly sensitive charge generating material is used, charge carriers tend to stay in the photosensitive layer during continuous use, making it difficult to mount on a high speed machine.

  Further, many organic electrophotographic photoreceptors have a structure in which a photosensitive layer is a laminate of a charge generation layer and a charge transport layer, and a surface layer (protective layer) for high durability is provided on the photosensitive layer. When a surface layer is provided, the interface between the layers is newly formed on the charge generation layer, so that charge trap sites increase and charge is accumulated, resulting in an afterimage, residual potential, post-exposure potential increase, etc. Problems arise and it becomes difficult to obtain good electrical characteristics and image characteristics. In addition, the charge generated in the charge generation layer crosses the energy barrier every time it passes through the interface, so that the charge generated from the charge generation layer is distributed, and is easily trapped at the interface. There is a problem that an abnormal image is generated more strongly.

The present invention has been made in view of the above-mentioned drawbacks of the prior art.
A first object of the present invention is to provide an electrophotographic photosensitive member that can obtain a stable high-quality image even when continuously used, and can cope with downsizing and mounting on a high-speed machine.
The second object of the present invention is to provide an electrophotographic photosensitive member that maintains excellent environmental stability and electrical characteristics over a long period of time, and prevents discharge destruction of a photoreceptor due to carrier adhesion or the like in a contact or proximity charging method or a two-component development method. To provide a body.
A third object of the present invention is to provide an image forming apparatus and a process cartridge provided with such an electrophotographic photosensitive member.

  As a result of repeated studies to achieve the above problems, the present inventor has found that the above object can be achieved with the following configuration, and has completed the present invention.

（６）前記金属酸化物粒子が、酸化チタン、酸化亜鉛、酸化アルミニウム、酸化ケイ素、酸化錫、酸化ジルコニウム、および酸化インジウムからなる群より選択される少なくとも１種の粒子であることを特徴とする前記（１）〜（５）のいずれかに記載の電子写真感光体。
（７）前記下引き層が、平均粒径の異なる２種以上の金属酸化物粒子を含有することを特徴とする前記（１）〜（６）のいずれかに記載の電子写真感光体。
（８）前記結着樹脂が、熱硬化性樹脂であることを特徴とする前記（１）〜（７）のいずれかに記載の電子写真感光体。
（９）前記下引き層の膜厚が１０μｍ以上４０μｍ以下であることを特徴とする前記（１）〜（８）のいずれかに記載の電子写真感光体。
（１０）前記下引き層が、直径１０ｍｍ以上２００ｍｍ以下の導電性円筒状支持体上に形成されていることを特徴とする前記（１）〜（９）のいずれかに記載の電子写真感光体。
（１１）少なくとも前記（１）〜（１０）のいずれかに記載の電子写真感光体と、帯電手段、画像露光手段、現像手段、および転写手段とを有することを特徴とする画像形成装置。
（１２）前記帯電手段が、接触または近接配置された帯電部材により帯電を行なう帯電手段であることを特徴とする前記（１１）に記載の画像形成装置。
（１３）画像形成装置本体に着脱自在に装着し得るプロセスカートリッジであって、前記（１）〜（１０）のいずれかに記載の電子写真感光体と、帯電手段、画像露光手段、現像手段、転写手段の中から選ばれた少なくとも１つの手段とをカートリッジ容器に組み込んで構成したものであることを特徴とするプロセスカートリッジ。
（１４）前記帯電手段が、接触または近接配置された帯電部材により帯電を行なう帯電手段であることを特徴とする前記（１３）に記載のプロセスカートリッジ。 (1) the electrically conductive substrate, comprising an electrophotographic photosensitive member comprising sequentially laminated an undercoat layer and a photosensitive layer, multi-porous particles undercoat layer was carrying the electron-transporting compound to the inner surface And an electrophotographic photosensitive member comprising metal oxide particles and a binder resin.
(2) The electrophotographic photosensitive member according to (1), wherein the porous particles are porous hollow particles having a shell having a plurality of pores.
(3) The above porous particles (1) or (2), wherein the porous particles are inorganic porous particles containing at least one element selected from the group consisting of titanium, silicon, zirconium, and aluminum. The electrophotographic photoreceptor described in 1.
(4) The electrophotographic photosensitive member according to (1), wherein the porous particles are crosslinked resin particles.
(5) The electron transporting compound is any of the electron transporting compounds represented by the following structural formulas (A-1), (A-2), (A-3), and (A-4). The electrophotographic photosensitive member according to any one of claims 1 to 4.

(6) The metal oxide particles are at least one particle selected from the group consisting of titanium oxide, zinc oxide, aluminum oxide, silicon oxide, tin oxide, zirconium oxide, and indium oxide. The electrophotographic photosensitive member according to any one of (1) to (5).
(7) The electrophotographic photosensitive member according to any one of (1) to (6), wherein the undercoat layer contains two or more kinds of metal oxide particles having different average particle diameters.
(8) The electrophotographic photosensitive member according to any one of (1) to (7), wherein the binder resin is a thermosetting resin.
(9) The electrophotographic photosensitive member according to any one of (1) to (8), wherein the thickness of the undercoat layer is 10 μm or more and 40 μm or less.
(10) The electrophotographic photosensitive member according to any one of (1) to (9), wherein the undercoat layer is formed on a conductive cylindrical support having a diameter of 10 mm to 200 mm. .
(11) An image forming apparatus comprising at least the electrophotographic photosensitive member according to any one of (1) to (10), a charging unit, an image exposing unit, a developing unit, and a transferring unit.
(12) The image forming apparatus according to (11), wherein the charging unit is a charging unit that performs charging by a charging member disposed in contact or close to the charging unit.
(13) A process cartridge that can be detachably attached to the image forming apparatus main body, the electrophotographic photosensitive member according to any one of (1) to (10), a charging unit, an image exposing unit, a developing unit, A process cartridge comprising at least one means selected from among transfer means and incorporated in a cartridge container.
(14) The process cartridge according to (13), wherein the charging unit is a charging unit that performs charging by a charging member disposed in contact with or close to the charging unit.

According to the present invention, it is possible to obtain a stable high-quality image that can effectively suppress the generation of a ghost image due to the retention of charge carriers in the photosensitive layer even when continuously used by a specific electrophotographic photosensitive member. Therefore, it is possible to provide an image forming apparatus that can cope with downsizing and mounting on a high-speed machine.
In addition, according to the present invention, it is possible to suppress the occurrence of interference fringes and the increase in residual potential due to scattering of laser light and the like, and at the same time, prevent charge injection from the conductive support and enhance the soiling suppression effect. Furthermore, even in an image forming apparatus using a contact charging system or a two-component developing system, an image forming apparatus capable of continuously forming excellent images without generating abnormal images due to carrier adhesion or the like can be provided.

1 is a schematic cross-sectional view showing an example of an electrophotographic photoreceptor according to the present invention. It is a schematic cross section which shows another example of the electrophotographic photoreceptor which concerns on this invention. FIG. 6 is a schematic cross-sectional view showing still another example of the electrophotographic photosensitive member according to the present invention. 1 is a schematic diagram illustrating an example of an image forming apparatus according to the present invention. It is the schematic which shows another example of the image forming apparatus which concerns on this invention. It is the schematic which shows another example of the image forming apparatus which concerns on this invention. 1 shows an example of a process cartridge according to the present invention. It is an example of the image pattern used for evaluation of an afterimage (ghost).

In the following, embodiments of the present invention will be described. For convenience of explanation, an example of the best mode of the present invention will be described mainly for a laminated type photoreceptor. However, the present invention is not limited to the multilayer photoreceptor.
The electrophotographic photosensitive member of the present invention, on a conductive support, an undercoat layer and a photosensitive layer are sequentially laminated, a multi-porous particles undercoat layer was carrying the electron-transporting compound to the inner surface of the metal It contains oxide particles and a binder resin.

Hereinafter, the electrophotographic photoreceptor of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view showing an example of the electrophotographic photosensitive member of the present invention, which contains at least porous particles, metal oxide particles, and a binder resin on a conductive support (21). A pulling layer (22) and a photosensitive layer (26) containing at least a charge generation material and a charge transport material are sequentially formed.

FIG. 2 is a cross-sectional view showing another configuration, and an undercoat layer (22) containing at least porous particles, metal oxide particles, and a binder resin on a conductive support (21). And an intermediate layer (23), a charge generation layer (24) containing at least a charge generation material, and a charge transport layer (25) containing at least a charge transport material.
FIG. 3 is a cross-sectional view showing still another configuration, and an undercoat layer (22) containing at least porous particles, metal oxide particles, and a binder resin on a conductive support (21). A charge generation layer (23) containing at least a charge generation material, and a charge transport layer (24) containing at least a charge transport material, and a protective layer (27) formed thereon. It is what.
The electrophotographic photosensitive member used in the present invention is formed by sequentially forming an undercoat layer containing at least porous particles, metal oxide particles, and a binder resin, and a photosensitive layer on a conductive support. If so, the above-described layers and the like may be arbitrarily combined.

<Conductive support>
As the conductive support (21), a material having a volume resistance of 10 ¹⁰ Ω · cm or less, for example, a metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, oxidation After metal oxide such as indium is deposited or sputtered, film or cylindrical plastic, paper coated, or nickel, stainless steel, etc., and extruding them into a tube by a method such as drawing, cutting Tubes with surface treatment such as superfinishing and polishing can be used. For aluminum elementary pipes, aluminum alloys such as JIS3003, JIS5000, and JIS6000 are formed into a tubular shape by a general method such as EI, ED, DI, or II. What performed surface cutting, grinding | polishing, anodizing treatment, etc. can be used.
In addition, an endless nickel belt, an endless stainless steel belt, or the like that can reduce the size of the apparatus because it can be laid out flexibly can be effectively used as the conductive support (21).

  As described above, an uncut aluminum tube may be used to reduce the cost of the conductive support. As a non-cutting aluminum tube for this purpose, as described in Japanese Patent Laid-Open No. 3-192265, a DI tube whose outer surface is finished by ironing after deep drawing an aluminum disk into a cup shape , II pipe with the outer surface finished by ironing after impact processing of the aluminum disc, EI pipe finished by ironing the outer surface of the aluminum extruded pipe, cold drawn ED after extrusion The tube is known. The surface roughness is preferably in the range of 10-point average roughness (Rz) of 0.05 to 1.0 μm and maximum height (Ry) of 0.5 to 1.5 μm. These non-cutting aluminum tubes are prone to abnormal images such as moire, but according to the photoconductor structure used in the present invention, the non-cutting aluminum tubes are clearly shown in the examples described later. An abnormal image such as moire does not occur even if it is used, and a high-quality image can be maintained at a low cost over a long period of time.

  In addition, in recent years, a material obtained by dispersing conductive powder in an appropriate binder resin and coating it on a plastic processed support can also be used as the conductive support (21) of the present invention. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, or metal oxide such as conductive titanium oxide, conductive tin oxide, and ITO. Examples include powder. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin. Such a conductive layer can be provided by dispersing and coating these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, 2-butanone, toluene and the like.

  Further, a heat shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, polytetrafluoroethylene-based fluororesin on a suitable cylindrical substrate. Those provided with a conductive layer can be used favorably as the conductive support (21) of the present invention.

<Underlayer>
At the photosensitive member used in the present invention, the undercoat layer (22) is provided between the conductive support (21) a photosensitive layer (26), at a minimum, an electron transporting compound to the inner surface of sputum and lifting the multi porous particles, and metal oxide particles, a layer containing a binder resin.

[Porous particles]
The porous particles contained in the undercoat layer (22) of the present invention can take various forms, but spherical particles are particularly preferably used. Also, two or more kinds having different particle diameters can be used in combination.
In the present invention, the porous particle is a particle having fine pores inside and outside the particle, and preferably a porous hollow particle. Here, the hollow porous particle means a hollow particle having a shell having a plurality of pores, and is generally characterized by having a large specific surface area as compared with a particle having a comparable particle diameter.

  The components constituting the porous particles are not particularly limited to inorganic materials, organic materials, or composites of organic and inorganic materials, and can be used alone or in combination of two or more. Examples of inorganic materials include calcium carbonate, barium carbonate, calcium silicate, magnesium silicate, cobalt carbonate, nickel carbonate, basic copper carbonate and other metal salts, titanium oxide, silica (anhydrous silicic acid), zinc oxide, alumina, copper oxide Metal oxides such as cobalt oxide and nickel oxide, barium titanate, and the like can be preferably used. As an example of the organic material, a polystyrene resin, a polyacrylate resin, a polyphenol resin, a cross-linked polystyrene-polyacrylate resin, or the like can be suitably used.

When the porous particles are composed of an inorganic material, a composite of organic and inorganic materials, the porous particles are made of a metal oxide containing at least one element selected from the group consisting of titanium, silicon, zirconium, and aluminum. It is preferable to include. The reason why the porous particles contain these metal oxides is good in dispersibility with metal oxides such as titanium oxide and zinc oxide and binder resins that are conductive pigments having appropriate resistance values. As a result, the electron transport compound supported by the porous particles is uniformly present in the undercoat layer without agglomeration, resulting in ghost image generation and residual potential. As a result, it is possible to reduce the increase of the image and to obtain the effect that a desired image can be continuously obtained.
In this case, the amount of the metal oxide in the porous particles is 0.01 to 100% by weight, preferably 30 to 100% by weight.

  Furthermore, the porous particles used in the present invention may be crosslinked resin particles. Preferable examples of the crosslinked resin include crosslinked styrene-acrylic hollow particles.

  The particle size of the porous particles used in the present invention is appropriately selected depending on the thickness of the undercoat layer to be formed, but a range of 0.01 to 10 μm is appropriate, preferably 0.05. The particles are about ˜3 μm. If it is larger than 10 μm, the smoothness of the film is lost, so that image unevenness occurs, and if it is smaller than 0.01 μm, a sufficient hollow ratio cannot be secured, and the cost increases due to production problems.

  The particle size referred to here is a volume average particle size, and is determined by an ultracentrifugal automatic particle size distribution analyzer: CAPA-700 (manufactured by Horiba, Ltd.). At this time, the particle diameter (Median diameter) corresponding to 50% of the cumulative distribution was calculated.

  Moreover, the hollow ratio as used in the field of this invention is the ratio P defined by the following Formula (1) in the picked-up image by a transmission electron microscope (TEM) and a scanning microscope (SEM).

  In the above formula (1), Rai represents the equivalent circle diameter of the inner contour (indicating the hollow portion contour) of the two contours constituting the image of the specific particle i, and Rbi represents the image of the specific particle i. Of the two contours to be constructed, the equivalent circular diameter of the outer contour (indicating the particle outer shape) is represented, n represents the number of measured particles, and n ≧ 100.

  Moreover, the hollow ratio (volume%) of the particles selected from the group consisting of the porous particles and porous hollow particles used in the present invention is in the range of 10% to 90%, more preferably 25% to 80%. is there. If the hollowness is less than 20%, the effect of supporting a sufficient electron transporting compound and light scattering properties cannot be imparted, and if it exceeds 90%, the particles may be destroyed during liquid preparation or coating in some cases. Therefore, there is a possibility that desired characteristics cannot be obtained.

The porous particle and porous hollow particle of the present invention have a shell having a plurality of pores, and the pore diameter is preferably a mesopore region having a diameter of 2 to 50 nm as defined by IUPAC, 5-30 nm is particularly preferable.
Furthermore, it is preferable that the pore size distribution has a single maximum value, and 60% or more of the total number of pores are present within the range of ± 1 nm of the average pore size. In the case of having a wide pore distribution, the amount of adsorption of the electron transporting compound becomes non-uniform, the mechanical strength is insufficient, and the hollow portion may be broken.

  The average pore size of the mesopores and the degree of pore size distribution are values calculated by the Berret-Joyner-Halenda (BJH) method from nitrogen adsorption isotherms by performing nitrogen adsorption measurement. Moreover, the observation in the picked-up image with a transmission electron microscope was also performed.

  The content ratio of the porous particles and / or the porous hollow particles in the undercoat layer is preferably in the range of 0.1 to 70% by weight, preferably about 5 to 50% by weight, based on the metal oxide particles. If the amount is less than 0.1% by weight, the effect of supporting a sufficient electron-transporting compound and functions such as light scattering properties cannot be imparted. If the amount exceeds 70% by weight, the binding force is insufficient and the conductive support is removed. Peeling may occur.

  The porous particles or porous hollow particles can be obtained by a known production method. Some of them are as follows.

(Porous particle production example 1)
Porous alumina particles:
To an isopropanol solution obtained by adding 150 ml of isopropanol to 30 g of aluminum tri-sec-butoxide, 14.6 ml of acetylacetone was added. After maintaining at 25 ° C. and stirring for 3 hours, 11 ml of water and 1 ml of 6N-nitric acid were further added. Let stand in an atmosphere with a relative humidity of 60% for 24 hours, then gradually raise the temperature to 90 ° C at a relative humidity of 30% and a heating rate of 0.1 ° C / min, hold for 1 hour, and dry in bulk A gel body was obtained.
The gel body was heated up to 400 ° C. at a rate of 0.1 ° C./min, further held at 400 ° C. for 2 hours, and then heated up to 1000 ° C. at a rate of temperature increase of 1 ° C./min. Holding for a time, alumina porous particles (particle size: 0.09 μm, pore size: 10 nm) were obtained.

(Porous particle production example 2)
Porous zirconia particles:
Surfactant: 86 ml of cetyltrimethylammonium chloride (0.1 mol / L aqueous solution) was added to 100 ml of zirconyl chloride octahydrate (0.1 mol / L aqueous solution), and the aqueous ammonia solution (concentration 0) was added to the stirred solution. .88 g / ml) was added with stirring until the pH reached 11.5 to obtain a gel-like solid precipitated product. The liquid mixture containing the precipitation component was transferred to a sealed container and stirred at 100 ° C. for 72 hours. Thereafter, the mixed solution containing the precipitated product was allowed to cool to room temperature, washed with pure water while suction filtration until the surfactant was not eluted, and then dried at 60 ° C. for 24 hours.
The obtained powder was calcined at 400 ° C. for 6 hours to remove the surfactant, thereby obtaining porous zirconia particles (particle size: 0.1 μm, pore size: 10 nm).

(Porous particle production example 3)
Porous titania hollow particles:
A water-in-oil emulsion was prepared by mixing 100 ml of toluene, 1.5 ml of distilled water, 24 mmol of octyltrichlorosilane, 0.24 mmol of sorbitan acid monostearate, 1 mmol of titanium tetraisopropoxide, and stirring ultrasonically.
By adding 24 mmol of methyltrichlorosilane to the resulting emulsion and stirring, filtering, washing, drying and firing in the air, porous titania hollow particles (hollow rate: 58%, average particle size: 1.2 μm, inner pore size) : 1.0 μm, pore diameter: 8 nm).

(Porous particle production example 4)
Porous polyimide particles:
Polyamic acid obtained by polymerization of 2,2- (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride and 4,4′-diaminodiphenyl ether , Dissolved in N-methylpyrrolidone at a concentration of 1.5% by mass. A solution was prepared by adding polyvinyl alcohol to the polyamic acid so as to be 20% by mass. 0.1 ml of this solution was added at 1500 r. p. Under a stirring condition of m, the surface of the particles is injected into 10 ml of cyclohexane containing 0.1% by mass of a neutral polymer surfactant (Acridick, manufactured by Dainippon Ink & Chemicals, Inc.) using a microsyringe. Thus, a dispersion of polyamic acid fine particles in which pores were formed could be obtained.
To each porous polyamic acid fine particle dispersion thus obtained, 0.1 ml of a mixed solution having a molar ratio of pyridine / acetic anhydride of 1/1 was added with stirring, and the porous polyamide was maintained for about 2 hours. Porous polyimide fine particles (particle size: 0.1 μm, pore size: 5 nm) were obtained while maintaining the porosity of the acid fine particles.

(Porous particle production example 5)
Hollow polymer particles:
Into a 1 liter reaction vessel, water as a medium, sodium dodecylbenzenesulfonate as an emulsifier, and sodium persulfate as a polymerization initiator were charged in advance. On the other hand, an aqueous dispersion of a monomer mixture was prepared by mixing and stirring methyl methacrylate, methacrylic acid, an emulsifier, and water. This monomer mixture was charged into the reaction vessel, and a polymerization reaction was performed at 75 ° C. for 6 hours while stirring the liquid in the reaction vessel to obtain an aqueous dispersion of polymer particles (1) having a particle size of 200 nm.
The obtained polymer particles (1) were put into a reaction vessel together with water and sodium persulfate as a polymerization initiator. Meanwhile, methyl methacrylate, methacrylic acid, divinylbenzene, emulsifier, and water are mixed and stirred to prepare an aqueous dispersion of the monomer mixture, and the liquid in the reaction vessel is stirred at 80 ° C. for about 6 hours. An aqueous dispersion of polymer particles (2) having a diameter of 400 nm was obtained.
Subsequently, the aqueous dispersion of the polymer particles (2) was charged into a reaction vessel together with water, methyl methacrylate, and sodium persulfate as a polymerization initiator. Meanwhile, styrene, an emulsifier and water were mixed and stirred to prepare an aqueous dispersion of the monomer. Polymerization of methyl methacrylate was performed in a state where the liquid in the reaction vessel was kept at 80 ° C. while stirring to obtain polymer particles (3) in which polymethyl methacrylate was combined with polymer particles (2).
Subsequently, the liquid in the reaction vessel was kept at 80 ° C. with stirring, and the aqueous dispersion of the monomer was charged into the reaction vessel, and styrene was polymerized and laminated on the surface layer of the polymer particles (3). At this time, acrylic acid is charged all at once into the reaction vessel and copolymerized with styrene. After all the monomers are added, the mixture is stirred for about 6 hours to obtain an aqueous dispersion of polymer particles (4) having a particle size of 1.5 μm. Got the body.
Next, the aqueous dispersion of the obtained polymer particles (4) was adjusted to pH 10 with ammonium hydroxide and subjected to heat treatment at 80 ° C. for 3 hours with stirring to obtain a particle size of 1.8 μm, Spherical hollow polymer particles having a single hole with an inner diameter of 1.4 μm and a hollow ratio of 47% were obtained.

(Porous particle production example 6)
Porous acrylic particles;
Toluene was added to a 1 liter reaction vessel, and a mixture of t-butyl methacrylate and AIBN (2,2′-azobis (isobutyronitrile)) prepared in advance was added while maintaining 100 ° C., By reacting for about 4 hours, a resin polymer (E) was obtained. The respective weight ratios were toluene / t-butyl methacrylate / AIBN = 90/90/1.
Polyvinyl alcohol (Kuraray Co., Ltd .: Poval PVA-105) was used as an aqueous dispersant solution for suspension polymerization, and di-t-butyl peroxide was used as a polymerization initiator.
As the acrylic resin particle composition, a monomer mixture comprising methyl methacrylate / trimethylolpropane trimethacrylate / resin polymer (E) / polymerization initiator = 30/20/5/1 was used.
The monomer solution was added to the reaction vessel while the above dispersant aqueous solution was added and stirred at 25 ° C. and 1000 rpm. After stirring for 15 minutes, the temperature was gradually raised and maintained at 50 ° C. for 30 minutes, and then the temperature was further raised to 63 ° C. and stirred for 4 hours. Thereafter, the reaction was terminated by cooling to near room temperature.
The reaction product was washed with water and then dried at 80 ° C. for 2 hours to obtain porous acrylic particles (particle size: 0.15 μm, pore size: 15 nm).

(Porous particle production example 7)
Porous silica hollow particles:
Add 100 ml of 2% ethyl acetate solution of polyoxyethylene lauryl ether to 500 ml of water glass and stir at high speed to prepare an oil-in-water (O / W type) emulsion. Subsequently, it added to 2000 ml of polyoxyethylene lauryl ether 3% ethyl acetate solutions, and stirred at high speed to prepare an oil-in-water-in-oil (O / W / O type) emulsion. This O / W / O type emulsion was added with 3000 ml of 1 mol / L ammonium sulfate, stirred, reacted, allowed to stand for 2 hours, and then separated by filtration. The obtained particles are inorganic porous silica fine particles. Finally, by evaporating ethyl acetate in the particles, porous silica hollow particles (hollow rate: 54%, average particle size: 0.8 μm, inner pore size) : 0.65 μm, pore diameter: 10 nm).

(Porous particle production example 8)
Porous alumina hollow particles:
A water-in-oil emulsion was prepared by mixing 100 ml of toluene, 1.5 ml of distilled water, 24 mmol of octyltrichlorosilane, 0.24 mmol of sorbitan acid monostearate, and 1 mmol of aluminum triisopropoxide, and stirring them ultrasonically.
Next, 24 mmol of methyltrichlorosilane was added to the resulting emulsion, and the mixture was stirred, filtered, washed, dried, and calcined in air to obtain porous alumina hollow particles (hollow rate: 42%, average particle size: 0.3 μm, (Inner pore diameter: 0.225 μm, pore diameter: 5 nm).

[Metal oxide particles]
The metal oxide particles contained in the undercoat layer (22) of the present invention include titanium oxide, zinc oxide, aluminum oxide, silicon oxide, tin oxide, zirconium oxide that hardly absorbs visible light and near infrared light. And particles selected from the group consisting of indium oxide are desirable for the purpose of covering defects on the support surface, preventing moire images, improving the carrier injection property of the photosensitive layer, and the like. Among these, titanium oxide and zinc oxide have appropriate conductivity and efficiently block hole injection from the support.

  As the metal oxide particles used in the present invention, those obtained in accordance with a production method usually used in industrial production can be used.

  For example, titanium oxide is produced by reacting ore with sulfuric acid to make a sulfate solution, clarifying the solution, precipitation of hydrous titanium oxide by hydrolysis, washing of hydrous titanium oxide, firing, grinding and surface treatment. First, the chlorine method, hydrofluoric acid method, titanium titanium chloride method, titanium tetrachloride aqueous solution method and the like can be obtained. Of these, the chlorine method is preferred for obtaining high-purity titanium oxide. In the chlorine method, the raw material titanium slag is chlorinated with chlorine to form titanium tetrachloride, which is separated, condensed and refined and then oxidized, and the resulting titanium oxide is pulverized, classified, surface treated as necessary, filtered, washed and dried This is a production method for producing titanium oxide by grinding.

  In addition, zinc oxide is a method in which an oxide such as aluminum, gallium, indium or tin is added to zinc oxide powder as an activator and heated and fired at a temperature of 600 to 1200 ° C. in a reducing atmosphere. A dry production method such as a method of heating and baking a mixture of zinc oxide powder and an activator in the presence, a mixture of a water-soluble zinc compound and the water-soluble compound of the metal as an activator, an alkali hydroxide or an alkali carbonate A coprecipitate precipitate produced by neutralization with an aqueous solution of the above is washed, dried or pre-baked, and then manufactured by a wet manufacturing method in which it is heated and fired at 500 to 1000 ° C. in a nitrogen atmosphere or a reducing atmosphere.

In general, metal oxide particles contain impurities such as hygroscopic substances such as Na ₂ O and K ₂ O and ionic substances, and this decrease in purity may affect electrophotographic characteristics. The metal oxide particles used in the present invention preferably have a purity of 95% or more.
Furthermore, in order to improve various properties such as dispersibility improvement, a surface-coated one or the like can be used as appropriate, and in order to perform a uniform surface treatment, the surface of the metal oxide particles is subjected to multiple times. It is also effective to use a treatment provided with a conductive coating layer as necessary in order to perform treatment or to obtain an appropriate specific resistance.

The metal oxide particles forming the undercoat layer are preferably a mixture of two kinds of particles having different average particle diameters. By using metal oxide particles having a small particle diameter, the surface of the support can be made minute. It is possible to remarkably improve the adhesion by filling the gaps between the uneven portions. Therefore, it can be formed on a small-diameter cylindrical support having a high shape curvature without causing peeling or cracking.
The average particle diameter of the metal oxide particles is 0.01 to 1.0 μm, preferably 0.02 to 0.8 μm. When the average particle size is smaller than 0.01 μm, the effect on the interference fringe pattern is reduced, and further, the dispersion stability of the coating liquid is lowered, and thus the effect on image defects such as black spots is also reduced. On the other hand, when the average particle size is larger than 1.0 μm, the smoothness of the surface of the undercoat layer is lowered, the coating property of the next laminated photosensitive layer is lowered, and the uniformity of the halftone image is further lowered.

When two or more kinds of metal oxide particles having different average particle diameters are mixed, the average particle diameter of the metal oxide particles having the largest average particle diameter is D ₁ , and the metal oxide particles having the smallest average primary particle diameter are when the average particle diameter is _{D 2,} preferably satisfy the relation of _{0.02 <(D 2 / D 1} ) ≦ 0.5.

The average particle size of the metal oxide particles in the present invention indicates a volume average particle size unless otherwise specified, and is measured by the following method.
After adding 10 g of metal oxide particles in 100 mL of water, adding a dispersant and adjusting the pH to 10.5, 200 g of zirconia beads (φ0.5 mm) was added and dispersed for 2 hours in a paint shaker. After dropping several drops of the obtained metal oxide dispersion into 300 mL of water adjusted to pH 10.5, the dispersion was further subjected to ultrasonic dispersion for 1 minute to prepare a measurement liquid for particle size distribution measurement. The measurement liquid was measured with a laser diffraction / scattering particle size distribution measuring device (HORIBA LA-910, manufactured by Horiba, Ltd.) to obtain a particle size distribution, and an average particle size value was obtained by an analysis mode possessed by the device.

When two or more kinds of metal oxide particles having different average particle diameters are mixed, the weight of the metal oxide particles having the largest average particle diameter is T ₁ , and the weight of the metal oxide particles having the smallest average particle diameter is When T ₂ is T2, the mixing ratio of these metal oxides is suitably 0.05 ≦ T ₂ / (T ₁ + T ₂ ) ≦ 0.95, more preferably 0.2 ≦ T ₂ / ( T ₁ + T ₂ ) ≦ 0.8.
When the mixing ratio: T ₂ / (T ₁ + T ₂ ) is smaller than 0.05, the metal oxide dispersed in the undercoat layer is not covered with the binder resin, and the conductivity is increased. May be formed. On the other hand, if it exceeds 0.95, it will be difficult to adjust the viscosity of the coating solution, and it will be difficult to form a uniform coating film.

  The amount of the metal oxide particles in the undercoat layer is preferably 30 to 95% by weight, more preferably 40 to 90% by weight, and particularly preferably 50 to 80% by weight. When the amount is less than 30% by weight, electric charge is accumulated in the undercoat layer and the residual potential is remarkably increased. When the amount is more than 95% by weight, the storage stability of the undercoat layer coating solution deteriorates, Since the oxide particles are precipitated, a uniform undercoat layer cannot be formed, and there is a tendency that scumming is more likely to occur.

[Binder resin]
The binder resin constituting the undercoat layer (22) is polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N-vinyl. Examples include carbazole, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, and the like. . Moreover, curable resin (thermosetting, ultraviolet curable, electron beam curable, etc.) is also mentioned. Of these, curable resins are preferably used. In general, since the electrical characteristics of the resin are significantly affected by temperature and humidity, a means for suppressing the occurrence of image defects such as black spot defects is required. In the present invention, a three-dimensional network structure is formed by using a curable resin, and this structure prevents the uptake of water molecules and the like into the coating film, and the undercoat layer in a state where the film formability is improved. Since it can be obtained, there is no sudden drop in resistance under high temperature and high humidity.
This effect is further improved by combining with two or more kinds of metal oxide particles having different average particle diameters according to the present invention, and an undercoat layer having a structurally dense and low hygroscopic property can be obtained.

Among the curable resins, examples of the thermosetting resin include an epoxy resin, an alkyd resin, a melamine resin, a phenol resin, a urethane resin, and a silicone resin. Since these thermosetting resins have a hydroxyl group, a carboxyl group, and an amino group, they can be crosslinked and cured by containing an appropriate curing agent.
As the curing agent, a known curing agent such as a melamine resin, a polyisocyanate resin, or a phenol resin can be used.

As the binder resin in the present invention, an alkyd-melamine resin or a phenol resin is preferably used from the viewpoint of electrical resistance and dispersibility of the metal oxide particles. Even if it is a commercial item of these resin, it can be used without a restriction | limiting in particular, You may use individually or in combination of 2 or more types.
Examples of commercially available alkyd resins include “Beckosol” series and “Super Beccosol” series manufactured by Dainippon Ink and Chemicals, Inc.
Commercially available melamine resins include, for example, “Super Becamine” series, which is a butylated melamine resin manufactured by Dainippon Ink and Chemicals, “Cymel” series manufactured by Mitsui Cytec, and “Summar” series manufactured by Sumitomo Chemical. And “Nikarak” series manufactured by Sanwa Chemical Co., Ltd.
As a commercial item of a phenol resin, for example, “Pryofen” series manufactured by Dainippon Ink & Chemicals, Inc. may be mentioned.

  The amount of the binder resin in the undercoat layer (22) of the present invention is preferably from 5 to 70% by weight, more preferably from 10 to 40% by weight, but the weight ratio between the metal oxide particles and the binder resin (metal oxidation) More preferably, the product particles / binder resin) is 2/1 to 8/1. If it is less than 2/1, the carrier transport performance in the undercoat layer is lowered, so that residual potential is accumulated or the photoresponsiveness is lowered. On the other hand, when the ratio exceeds 8/1, voids in the undercoat layer increase, and bubbles are generated when an intermediate layer is formed on the undercoat layer.

(Electron transporting compound)
The undercoat layer (22) of the present invention preferably contains an electron transporting compound.
Examples of the electron transporting compound used in the present invention include fluorenone compounds such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitrofluorenone, and imide compounds such as pyromellitic imide and naphthylimide. Quinone compounds such as benzoquinone, diphenoquinone, diiminoquinone, naphthoquinone, stilbenequinone, anthraquinone, fluorenylidene compounds such as fluorenylideneaniline and fluorenylidenemalononitrile, carboxylic acid anhydrides such as phthalic anhydride, thiopyran dioxide, etc. Examples thereof include electron-withdrawing substances such as cyclic sulfone compounds, oxadiazole compounds, and triazole compounds, those obtained by polymerizing these electron-withdrawing substances, and pigments such as azo pigments, perylene pigments, and quinone pigments. For That compound is not limited thereto.

  The content of the electron transporting compound can be arbitrarily selected as long as desired electrical characteristics can be obtained, but is 0.001 to 10% by mass, preferably 0.05 to 5% with respect to the undercoat layer (21). It is contained by mass. When the content is 0.001% by mass or less, the residual potential is increased and a ghost image is generated by repeated use.

(Formation of undercoat layer (22))
In forming the undercoat layer (22) is a multi-porous particles to the onset Ming inner surface was carrying the electron-transporting compound, and metal oxide particles and the binder resin, other additives as required An undercoat layer coating solution in which an agent (for example, an electron transporting compound, metal oxide particles, etc.) is mixed and dispersed in an appropriate solvent is used.
Solvents include aliphatic alcohol solvents such as methanol, ethanol, n-propanol and n-butanol, ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone, and cyclic or linear chains such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether. Examples include ether solvents, aromatic hydrocarbon solvents such as toluene, ethyl cellosolve, methyl cellosolve, etc., and these can be used alone or in admixture of two or more.

Examples of the method for fixing (coating) the porous particles contained in the undercoat layer (22) of the present invention and the electron transporting compound include a dry fixing method and a wet fixing method. Preferably used.
First, at least one kind of particles selected from the group consisting of the porous particles of the present invention and porous hollow particles, an electron transporting compound, a solvent, and a medium are put into a container. If necessary, metal oxide particles, antifoaming agents, and pigment dispersants contained in the undercoat layer can also be added. Next, stirring is performed while keeping the temperature inside the container constant to make the inside of the container uniform. Thereafter, the stirring speed is gradually increased so that the electron transporting compound collides with the inner surface of the particles and is buried.
After sufficiently stirring, stirring is stopped, and decantation is performed a plurality of times by suction filtration to obtain particles in which the electron transporting compound is fixed to the porous particle particles. The cleaning liquid used for decantation is the same as the above solvent.
Moreover, you may heat-process as needed after a sticking process. The heat treatment step can be performed by air drying or static drying at 30 ° C. to 200 ° C., preferably 40 ° C. to 150 ° C. for 5 minutes to 5 hours, preferably 30 minutes to 2 hours.
In the wet fixing method, the amount of the electron transporting compound fixed depends on the concentration of the porous particles, the electron transporting compound, and the medium in the container, the stirring speed and the stirring time at the time of mixing. It selects suitably in the range with which an electrical property is acquired.

  Further, the fixing method of the electron transporting compound is not limited to the above method, and any method can be selected as long as desired electric characteristics are obtained.

The coating of the undercoat layer (22) may be thermally cured immediately after application of the undercoat layer, or may be performed by overheating when forming the photosensitive layer (26) formed on the undercoat layer. .
The drying temperature may be 10 ° C. to 250 ° C., preferably 100 ° C. to 200 ° C. for 5 minutes to 5 hours, preferably 10 minutes to 2 hours by blow drying or static drying.
The thickness of the undercoat layer is preferably 3 μm or more, and more preferably about 10 to 40 μm.
The film thickness of the undercoat layer (22) was measured using an eddy current film thickness meter Fischer scope MMS (manufactured by Fischer Instruments).

<Relationship between undercoat layer and contact charging method>
In recent years, in the contact charging method that has become the mainstream, a local high electric field is applied to the locally deteriorated portion of the photoconductor during contact charging, or conductive foreign matter generated from within the electrophotographic apparatus. However, there is a problem of dielectric breakdown caused by contact in the photosensitive member or penetration into the photosensitive member to form a conductive path between the contact charging device and the support.

  In addition, a development method using a two-component developer composed of a magnetic carrier and a toner that has been widely put into practical use includes a contact two-component development method in which development is performed while the developer magnetic brush rubs the surface of the photoreceptor, and the developer. Although it is classified as a non-contact two-component development method in which the magnetic brush does not come into contact with the photoconductor, it is a contact two-component that provides excellent fine line reproducibility and sufficient image density, especially in full-color copying machines that require high-definition images. System development is preferably used.

  Furthermore, with the increasing demand to achieve high image quality by reducing the particle size of the toner, the carrier particle size must be reduced. Since the small particle size carrier has a large surface area per unit volume, it can give sufficient frictional charge to individual toners, and the occurrence of low charge amount toner and reversely charged toner is small. Since the magnetic brush ears formed in the gap (development nip) become dense and a sufficient contact probability with the photoconductor can be obtained, the effect of improving the image quality can be expected.

However, the reduction in the particle size of the carrier causes a weakening of the magnetic binding force received from the magnetic field generated by the magnet in the developing roller, causing particles to scatter and causing the problem of carrier adhesion to the photoreceptor, resulting in the photoreceptor. An abnormal image is generated due to the dielectric breakdown.
As a means to suppress this breakdown, it is very effective to increase the thickness of the undercoat layer. However, in the conventional configuration, a resistance that can control charge injection from the conductive support and maintain a low residual potential over a long period of time. In order to achieve both control functions, there were significant restrictions.

  For example, when charge is injected from the support, the charging property is lowered, and in the case of the reversal development method, innumerable black spots are generated in a white background area where an image is not printed, while the electric resistance is high. If it is too high, it becomes difficult for the charges (electrons) generated in the photosensitive layer to move to the support via the undercoat layer, so that it stays inside the photosensitive layer, and as a result, the residual potential is increased or repeatedly used. It is the cause of potential fluctuation.

  Furthermore, it is effective to use a charge generating material having high sensitivity as the trend of using a small-diameter electrophotographic photosensitive member at a high linear velocity. However, since the amount of charge generated by exposure increases, Electrons after being injected into the charge transport layer tend to stay in the charge generation layer, resulting in a delay in the rise of the surface potential during charging and the problem of ghost images.

  Therefore, in order to solve this problem, it is essential to improve the injection property of electrons from the photosensitive layer to the support. Therefore, the method of containing an electron transporting compound in the undercoat layer is effective. However, even when an electron transporting compound is used in the conventional method, the coating layer is applied when the photosensitive layer is formed on the undercoat layer by coating. At the time of formation, there was a problem that the electron transporting compound was eluted, and sufficient electron transporting property could not be maintained.

  The reason why the above-described problem that cannot be achieved by the conventional technique is solved by the configuration of the undercoat layer (22) of the present invention is considered as follows.

  The first effect of the inclusion of the porous particles in the undercoat layer in the present invention is that the increase in the specific surface area per unit volume increases the adhesion area with the binder resin. Effectively blocks charge injection, dramatically improves the resistance adjustment function, and has a sufficient film thickness to suppress dielectric breakdown due to carrier adhesion, etc., even in image forming apparatuses using contact charging and two-component development methods A thick undercoat layer can be formed.

  For example, for the purpose of reducing electrical resistance, for example, metal oxide particles coated with tin oxide, and in order to obtain good electrical conductivity between the particles, the voids formed in the undercoat layer are filled. Even when a metal oxide having a small particle size is used, it is possible to achieve both the function of adjusting resistance and the function of blocking charges from the support without causing charge injection from the conductive support.

  The constitution of the undercoat layer of the present invention is such that the porous particles hold the binder resin on the surface thereof, and the contact frequency between the particles constituting the undercoat layer and the binder resin can be balanced, so that the uniform membrane resistance Is obtained.

Further, in an image forming apparatus using a contact or proximity charging method or a two-component developing method, even when conductive foreign matter adheres to or penetrates the surface of the photosensitive member, the present invention is applied under the thick film having an appropriate resistance value. Since it is possible to form the pulling layer, it is considered that the occurrence of dielectric breakdown of the photosensitive layer caused by application of a local high electric field is reduced.
In addition, since the elastic force (cushioning property) of the hollow and porous particles itself relieves local stress concentration due to volume shrinkage during film formation, not only during film formation, but also image formation such as cleaning and charging. It also functions as a buffer layer that absorbs external stress during image formation, such as members, and the function of the undercoat layer can be dramatically enhanced.

The second effect is that the porous particles carry an electron transporting compound as a functional substance and improve the electron injecting property from the photosensitive layer to the conductive support.
That is, the microcapsule technology is applied, and hollow porous particles are particularly preferable. This is because hollow porous particles can contain more electron transporting compounds.

In the present invention, since the undercoat layer contains porous particles carrying an electron transporting compound, the electrons that are the cause of increasing the residual potential are present at the interface with the charge generation layer or in the undercoat layer. It moves quickly to the conductive support without stagnation.
In addition, the electrons generated by the charge generation material do not move to the support side, and do not cause a decrease in charging potential caused by recombination with holes in the charge generation layer. Since the electrons move smoothly at the interface, the photoresponsiveness is remarkably improved.
Furthermore, the ghost image suppression effect is improved. As described above, a ghost image is a halftone image in an image that is supposed to be a uniform image when a halftone image is output after outputting a clear and dark image in an electrophotographic image forming apparatus. This is a phenomenon in which the image pattern output before the surface of the image is exposed. Of the charges generated in the photosensitive layer by image exposure, electrons that should flow out to the support side do not stay and move smoothly. Therefore, there is no history of the portion irradiated with light during the previous rotation.

The third effect is that the porous particles carry an electron transporting compound as a functional substance, and the electron injecting property from the photosensitive layer to the conductive support regardless of the solubility of the electron transporting compound in an organic solvent. Is to improve.
After coating the coating solution for the undercoat layer containing the electron transporting compound on the conductive support, the elution of the electron transporting compound is prevented even when the photosensitive layer is subsequently coated thereon, A sufficient electron transport function can be provided without segregation in the undercoat layer. Further, since aggregation and crystallization are not caused in the undercoat layer, the degree of freedom in designing the photoreceptor is high, and the desired effect can be obtained at a low cost.
The third effect also applies the microcapsule technique as described above, and hollow porous particles are particularly suitable. This is because hollow porous particles can contain more electron transporting compounds.

The fourth effect is that when the porous particles are dispersed in the organic solvent together with the binder resin, they are difficult to settle in the coating solution, and the dispersion stability is improved, so that a uniform coating film can be formed. It is to become.
The properties of the subbing layer are highly dependent on dispersibility, and it is essential to select a desirable dispersion state that provides an optimum resistance value that is always stable over the entire environment from low temperature and low humidity to high temperature and high humidity. And, according to the composition of the undercoat layer of the present invention, the coating film uniformity is good without causing ground contamination due to local film resistance bias caused by poor dispersibility, and no increase in residual potential, A photoreceptor having stable potential characteristics and image characteristics in repeated use can be produced.

  The fifth effect is that functions such as light scattering can be more effectively improved because the porous particles are hollow particles. That is, by using hollow particles, for example, in the case of crosslinked polymer particles, the refractive index of light is different between the polymer portion forming the organic shell and the internal space, so that the effect of scattering and shielding light is exhibited. Therefore, such crosslinked polymer particles can be effectively used as a light scattering component of the light scattering material.

  In an image forming apparatus using a semiconductor laser as an image exposure means, incident light at the time of image exposure interferes with reflected light that is transmitted through the photosensitive layer and reflected from the conductive support. It tends to cause problems that cause uneven density. As a countermeasure against this interference fringe, the method of subjecting the surface of the conductive support or the undercoat layer to a roughening treatment has drawbacks such as an increase in manufacturing cost because the manufacturing process becomes complicated. Then, it is possible to improve productivity because particles having a light scattering function are dispersed together with a metal oxide or an appropriate binder resin and a conductive support is coated by a dip coating method. .

  Further, the undercoat layer of the present invention increases the degree of freedom in selecting the conductive support. The shape is selected depending on the configuration of the image forming apparatus to be used, such as a sheet shape or a cylindrical shape, but the most typical cylindrical support is exemplified by a non-cutting tube that does not require surface cutting and a cutting tube. Broadly divided. Non-cutting pipes are preferable in terms of mass productivity and cost reduction, but on the other hand, the defects that have existed on the surface of the support so far have adversely affected the image. The pulling layer allows complete coverage.

<Intermediate layer>
In the photoreceptor of the present invention, an intermediate layer (23) can be provided between the undercoat layer (22) and the photosensitive layer (26) as necessary. Considering that the photosensitive layer is applied with a solvent on the intermediate layer (23), it is desirable that the intermediate layer (23) has a high solvent resistance with respect to a general organic solvent.
Therefore, the intermediate layer (23) is not affected by electrical characteristics even in environments such as high temperature and high humidity and low temperature and low humidity, and has excellent potential stability even in repeated use. Therefore, it contains zirconium, titanium, silicon, and the like. It is preferably formed of a cured film containing an organometallic compound.

  Examples of zirconium compounds include zirconium tri-n-butoxide pentanedionate, zirconium di-n-butoxide (bis-2,4-pentanedionate), zirconium triisopropoxide pentanedionate, zirconium diisopropoxide. Side (bis-2,4-pentanedionate), zirconium tri-n-butoxide ethyl acetoacetate, zirconium di-n-butoxide (bisethyl acetoacetate), zirconium tri-n-butoxide methyl acetoacetate, zirconium di -N-butoxide (bismethylacetoacetate), zirconium diisopropoxide bis (2,2,6,6, -tetramethyl-3,5, -heptanedionate), zirconium bis (triethanolamine) di-n Examples include butoxide, zirconium lactate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide, etc., but are not limited thereto, and these may be used alone or in combination of two or more. Also good.

  Examples of titanium compounds include titanium tri-n-butoxide pentanedionate, titanium di-n-butoxide (bis-2,4-pentanedionate), titanium triisopropoxide pentanedionate, titanium diisopropoxide. Side (bis-2,4-pentanedionate), titanium tri-n-butoxide ethyl acetoacetate, titanium di-n-butoxide (bisethyl acetoacetate), titanium tri-n-butoxide methyl acetoacetate, titanium di -N-butoxide (bismethylacetoacetate), titanium diisopropoxide bis (2,2,6,6, -tetramethyl-3,5, -heptanedionate), titanium bis (triethanolamine) di-n -Butoxide, Titani Murakuteto, methacrylate titanium butoxide, not intended to stearyl rate of titanium butoxide, but isostearate titanium butoxide, and the like are limited to, may be used in combination singly or two or more.

In addition to the metal organic compound, a silane coupling agent may be mixed and used for forming the intermediate layer (23).
Examples of the silane coupling agent include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and N-β-. (Aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyl Trimethoxysilane, γ-aminopropyltriethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmonomethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, monophenyltrimethoxysilane Examples include lanthanum, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, and γ-methacryloxypropyltrimethoxysilane.

When a silane coupling agent is used, the mixing ratio of the organometallic compound and the silane coupling agent can be appropriately set as necessary. However, the volume resistivity after forming the coating film is 10 on electrophotographic characteristics. ^The mixing ratio is preferably set so as to be ¹⁰ to 10 ¹³ Ω · cm. The bulk resistance of the intermediate layer is measured by a usual method. For example, after forming an intermediate layer on an electrode, a counter electrode is formed by a vapor deposition method or the like to form a sample such as a sandwich cell. By using this, the bulk resistance can be measured by evaluating the voltage-current characteristics in the dark state. At this time, it is also possible to measure by pressing a conductive rubber or metal foil as the counter electrode.

  In forming the intermediate layer, an intermediate layer coating solution in which an organometallic compound is mixed in an appropriate solvent is used. Solvents used in the intermediate layer coating solution include aliphatic alcohol solvents such as methanol, ethanol, propanol and butanol, aromatic hydrocarbon solvents such as toluene, and ester solvents such as ethyl acetate and cellosolve acetate. These can be used alone or in admixture of two or more.

  Examples of the coating method for forming the intermediate layer (23) include dip coating, spray coating, blade coating, wire bar coating and the like, and the drying temperature is 10 ° C to 250 ° C, preferably 100 ° C to 200 ° C. In the range of 5 minutes to 6 hours, preferably 10 minutes to 2 hours. The coating of the intermediate layer (23) may be thermally cured immediately after the application of the intermediate layer, but the undercoat layer (22) or the photosensitive layer (26) on the intermediate layer (in the case of a laminated structure, You may carry out by the overheating at the time of forming a charge generation layer (24)).

  The film thickness of the intermediate layer is preferably 3 μm or less having an electrical blocking function without causing an increase in residual potential and a decrease in sensitivity, and more preferably about 0.05 to 1.0 μm.

<Photosensitive layer>
Next, the photosensitive layer (26) will be described. The photosensitive layer (26) in the present invention may have a laminated structure or a single layer structure, but here, for convenience of explanation, the laminated structure will be described first.

First, the charge generation layer (24) will be described.
The charge generation layer (24) is a layer mainly composed of a charge generation material for the purpose of generating and separating latent image charges by image exposure, and a binder resin can be used in combination as required.
As the charge generation material, inorganic materials and organic materials can be used.

  Inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, amorphous silicon, and the like. In amorphous silicon, dangling bonds terminated with hydrogen atoms or halogen atoms, or doped with boron atoms, phosphorus atoms or the like are preferably used.

  On the other hand, a known material can be used as the organic material. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having carbazole skeleton, azo pigments having triphenylamine skeleton, azo pigments having diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having a fluorenone skeleton, azo pigments having an oxadiazol skeleton, azo pigments having a bis-stilbene skeleton, azo pigments having a distyryloxadiazole skeleton, azo pigments having a distyrylcarbazole skeleton, perylene Pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine dyes, Goido based pigments, and bisbenzimidazole pigments. These charge generation materials can be used alone or as a mixture of two or more.

Examples of the binder resin used for the charge generation layer (24) include polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, and poly-N-vinylcarbazole. , Polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone and the like. Of these, polyvinyl butyral is often used and is useful.
These binder resins may be used alone or as a mixture of two or more.
The amount of the binder resin is suitably 0 to 500 parts by mass, preferably 10 to 300 parts by mass with respect to 100 parts by mass of the charge generating material.

In addition, a polymer charge transport material can be used as the binder resin of the charge generation layer (24).
The following known materials can be used as the polymer charge transport material.
For example, a polymer having a carbazole ring such as poly-N-vinylcarbazole, a polymer having a hydrazone structure exemplified in JP-A-57-78402, and JP-A-63-285552 are exemplified. Polysilylene polymer, JP-A-8-269183, JP-A-9-151248, JP-A-9-71642, JP-A-9-104746, JP-A-9-328539, JP-A-9-272735 JP-A-9-241369, JP-A-11-29634, JP-A-11-5836, JP-A-11-71453, JP-A-9-221544, JP-A-9-227669, Japanese Laid-Open Patent Publication No. 9-157378, Japanese Laid-Open Patent Publication No. 9-302084, Japanese Laid-Open Patent Publication No. 9-302085, Japanese Laid-Open Patent Publication No. 9-268. 26, JP-A No. 9-235367, JP-A No. 9-87376, JP-A No. 9-110976 discloses, aromatic polycarbonates disclosed in JP-2000-38442. These polymer charge transport materials can be used alone or as a mixture of two or more.

  The charge generation layer (24) may contain a low molecular charge transport material. Low molecular charge transport materials that can be used in combination with the charge generation layer (24) include hole transport materials and electron transport materials.

  Examples of the electron transporting material include chloroanil, bromanyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and diphenoquinone derivatives. These electron transport materials can be used alone or as a mixture of two or more.

  Examples of the hole transporting material include the electron donating materials shown below and are used favorably. As hole transport materials, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triaryls Other known materials such as methane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, and the like can be given. These hole transport materials can be used alone or as a mixture of two or more.

  Moreover, various additives, such as leveling agents, such as a dimethyl silicone oil and a methylphenyl silicone oil, a sensitizer, and a dispersing agent, can be added as needed.

The method for forming the charge generation layer (24) can be broadly divided into a vacuum thin film preparation method and a casting method from a solution dispersion system.
As the former method, a vacuum vapor deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is used, and the above-described inorganic materials and organic materials can be satisfactorily formed.
Further, in order to provide the charge generation layer by the latter casting method, a ball mill using the above-described inorganic or organic charge generation material together with a binder resin if necessary and a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone, etc. It can be formed by dispersing with an attritor, a sand mill or the like, and applying the solution after diluting the dispersion appropriately. The coating can be performed using a dip coating method, a spray coating method, a bead coating method, or the like.

  The film thickness of the charge generation layer (24) provided as described above is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm.

Next, the charge transport layer (25) will be described.
The charge transport layer (25) is a layer intended to hold a charged charge and to couple the charge generated in the charge generation layer (24) by exposure to the charged charge held by movement. In order to achieve the purpose of holding the charged charge, high electrical resistance is required, and in order to achieve the purpose of obtaining a high surface potential with the held charged charge, the dielectric constant is low and the charge mobility is good. Is required. The charge transport layer for satisfying these requirements can be formed by dissolving or dispersing the charge transport material and the binder resin in an appropriate solvent, and applying and drying the solution on the charge generation layer (24).

  As the charge transport material, the electron transport material and the hole transport material described in the charge generation layer (24) can be used.

  Examples of the binder resin include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester resin, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate. , Polyvinylidene chloride, polyarylate resin, phenoxy resin, acrylic resin, methacrylic resin, polycarbonate resin, epoxy resin, melamine resin, urethane resin, silicone resin, fluorine resin, cellulose acetate resin, ethyl cellulose resin, etc. You may mix and use seed | species or more resin.

  The content of the charge transport material is appropriately 20 to 300 parts by mass, preferably 40 to 150 parts by mass with respect to 100 parts by mass of the binder resin.

  For the charge transport layer (25), a polymer charge transport material having a function as a binder resin and a function as a charge transport material is also preferably used. A charge transport layer composed of these polymer charge transport materials is excellent in wear resistance and effective. In the present invention, these polymer charge transport materials may be mixed with the aforementioned binder resin or low molecular charge transport material. As the polymer charge transport material, known materials as described in the charge generation layer (24) can be used, and in particular, a polycarbonate having a triarylamine structure in the main chain and / or side chain is preferable. Used.

  A leveling agent, a plasticizer, etc. can be added to the charge transport layer (25) as necessary.

  Leveling agents that can be used in combination include silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain, and the amount used is 0 with respect to 100 parts by weight of the binder resin. About 1 part by weight is appropriate.

  Examples of the plasticizer that can be used in combination include halogenated paraffin, dimethylnaphthalene, dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, and polymers such as polyester and copolymers, and the amount used is a binder resin. About 0 to 30 parts by weight is appropriate for 100 parts by weight.

  Examples of the solvent used include tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, and acetone. Among them, the use of non-halogen solvents is desirable for the purpose of reducing environmental burdens, and specifically, cyclic ethers such as tetrahydrofuran, dioxolane, dioxane, aromatic hydrocarbons such as toluene, xylene, and the like. Derivatives are used favorably.

  As the coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed. During coating, when the coating solution dissolves the lower photosensitive layer, it is easy to control the contact time between the lower layer and the coating solution, the contact amount between the lower layer and the solvent in the coating solution, It is preferable to use a spray coating method, a ring coating method, or the like.

  The film thickness of the charge transport layer (25) is suitably about 5 to 100 μm, and preferably about 10 to 40 μm.

Furthermore, when the charge transport layer (25) is the outermost layer of the photoreceptor, it is effective to contain at least one kind of particles selected from the group consisting of inorganic particles and organic particles.
In general, organic photoreceptors have a major drawback of low durability.
Roughly divided into durability against mechanical loads such as abrasion and scratches on the surface of the photoconductor and electrostatic properties such as accumulation of residual potential and deterioration of chargeability due to repeated use, it is inferior in mechanical durability. Is also a factor that determines the life of the photoreceptor. In addition to the durability, the surface layer of the photosensitive member has factors that cause image deterioration such as adhesion of a low-resistance substance generated by ozone generated during corona charging, filming due to poor cleaning of the toner, and fusion. Therefore, releasability of various deposits on the surface of the photoconductor that determines the life of the photoconductor as well as mechanical durability is also required.

  In order to satisfy these requirements, the inclusion of inorganic or organic particles in the outermost layer of the photoreceptor is extremely effective. Inorganic particle materials include metals such as silica, tin oxide, zinc oxide, titanium oxide, alumina, zirconium oxide, indium oxide, antimony oxide, bismuth oxide, calcium oxide, antimony-doped tin oxide, and tin-doped indium oxide. Examples include oxides, metal fluorides such as tin fluoride, calcium fluoride, and aluminum fluoride, potassium titanate, and boron nitride. Examples of organic particle materials include fluorine resin powders such as polytetrafluoroethylene, and silicone resins. Examples thereof include powder and a-carbon powder. In addition to these materials, known materials can also be used, and the inorganic and organic particles described above can be used alone or in combination of two or more.

Furthermore, these particles are preferably surface-treated with at least one inorganic substance or organic substance for reasons such as improving dispersibility and modifying surface properties.
Lowering the dispersibility of the particles not only increases the residual potential, but also lowers the transparency of the coating film, causes coating film defects, and lowers the abrasion resistance. It can develop into a big problem.
As the surface treatment agent, all conventionally used surface treatment agents can be used, but the above-described surface treatment agent capable of maintaining the insulating properties of the particles is preferable. For example, a titanate coupling agent, an aluminum coupling agent, a zircoaluminate coupling agent, a higher fatty acid, etc., or a mixing treatment of these with a silane coupling agent, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Silicone, aluminum stearate, or the like, or a mixture treatment thereof is preferable in terms of particle dispersibility. Although the treatment with the silane coupling agent is somewhat reduced in resistance, the influence may be suppressed by applying a mixing treatment of the surface treatment agent and the silane coupling agent. The surface treatment amount varies depending on the average primary particle size of the particles used, but is preferably 3 to 30% by weight, and more preferably 5 to 20% by weight.

  As dispersion solvents, methyl ethyl ketone, acetone, methyl isobutyl ketone, cyclohexanone ketones, ethers such as dioxane, tetrahydrofuran and ethyl cellosolve, aromatics such as toluene and xylene, and esters such as ethyl acetate and butyl acetate are used. . As the dispersing means, known dispersing means such as a ball mill, a sand mill, and a vibration mill can be used.

When the charge transport layer (25) is the outermost layer, the content of inorganic particles and organic particles contained is preferably 0.1 to 40% by weight, more preferably 0.1 to 30% by weight, based on the total solid content. It is. When the content is less than 0.1% by weight, it is not preferable in terms of wear resistance. On the other hand, if it exceeds 40% by weight, image degradation such as a decrease in resolution due to film opacification and a decrease in image density due to a decrease in sensitivity occurs.
The volume average particle diameter of the inorganic particles or organic particles is preferably 0.05 to 1.0 μm, preferably 0.05 to 0.8 μm. If the particle size is smaller than 0.05 μm, uniform dispersion is difficult to achieve, and if the particle size is larger than 1.0 μm, the particles may cue up on the surface of the photoreceptor, which may damage the cleaning blade and cause poor cleaning.

Next, the case where the photosensitive layer (26) has a single layer structure will be described.
So far, the case where the photosensitive layer is laminated has been described, but in the present invention, the photosensitive layer (26) may have a single layer configuration. The photosensitive layer (26) having a single layer structure is prepared by dissolving or dispersing the above-described charge generating substance, charge transporting substance, binder resin or the like in an appropriate solvent, and applying this onto the undercoat layer (21) of the present invention. It can be formed by drying. As the binder resin, the materials mentioned in the description of the charge generation layer (24) and the charge transport layer (25) can be used. Furthermore, the above-described polymer charge transport material is also used favorably because it has the functions of a binder resin and a charge transport material.

Moreover, the inorganic and organic particles described in the explanation of the charge transport layer (25) can also be used favorably.
The photosensitive layer (26) is obtained by dissolving or dispersing a charge generating material and a binder resin together with a charge transporting material in a solvent such as tetrahydrofuran, dioxane, dichloroethane, cyclohexanone, toluene, methyl ethyl ketone, acetone, and dip coating or spray coating. It can be formed by coating with bead coat or ring coat.
Further, if necessary, various additives such as the above-mentioned plasticizer and leveling agent can be added.
The film thickness of the photosensitive layer (26) is suitably about 5 to 50 μm, preferably about 10 to 40 μm.

<Protective layer>
In the photoreceptor of the present invention, for the purpose of protecting the photosensitive layer, the protective layer (27) may be provided on the photosensitive layer (26) (in the case of a laminated structure, the charge transport layer (25)).
Materials used for this include ABS resin, ACS resin, olefin / vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene, Polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone, AS resin, AB resin, BS resin, polyurethane, polyvinyl chloride, polyvinylidene chloride, Resins such as epoxy resins can be used.
In addition to the protective layer (27), for the purpose of improving wear resistance, at least one kind of particles selected from the group consisting of inorganic particles and organic particles described in the explanation of the charge transport layer (25) is added. You can also.

As a method for forming the protective layer (27), a normal coating method is employed.
In addition, about 0.5-10 micrometers is suitable for the thickness of a protective layer (27). In addition to the above, known materials such as i-C and a-SiC formed by a vacuum thin film manufacturing method can also be used as the protective layer. Further, if necessary, the aforementioned charge transporting material, antioxidant, plasticizer and leveling agent can be added.

In the present invention, an antioxidant may be added for the purpose of preventing the decrease in sensitivity and the increase in residual potential, in order to improve environmental resistance. The antioxidant may be added to any layer containing an organic substance, and all known antioxidants can be used.
Moreover, the effect may increase remarkably by mixing and adding 2 or more types of antioxidant, and it is effective.
The following are mentioned as antioxidant which can be used for this invention.

(Phenolic compounds)
2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, n-octadecyl-3- (4′-hydroxy-3 ′, 5 '-Di-t-butylphenol), 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2,2'-methylene-bis- (4-ethyl-6-t-butylphenol) 4,4′-thiobis- (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1,3-tris- (2- Methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis- [Methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4′-hydroxy-3′-t-butylphenyl) butyric acid] Cricol esters, tocopherols, etc.

(Paraphenylenediamines)
N-phenyl-N'-isopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylenediamine, N, N'- Di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine and the like.

(Hydroquinones)
2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2- (2-octadecenyl) ) -5-methylhydroquinone and the like.

(Organic sulfur compounds)
Dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like.

(Organic phosphorus compounds)
Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine, and the like.

These compounds are known as antioxidants such as rubbers, plastics and fats and oils, and commercially available products can be easily obtained.
The addition amount of the antioxidant in the present invention is 0 to 10% by weight based on the total weight of the layer to be added.

<Image Forming Method / Image Forming Apparatus>
Next, the image forming apparatus of the present invention will be described in detail with reference to the drawings.
The present invention provides the above-described electrophotographic photoreceptor, and an image forming method using the electrophotographic photoreceptor of the present invention, a charging unit, an image exposing unit, a developing unit, and a transfer unit, and the An image forming apparatus having a photographic photosensitive member, a charging unit, an image exposing unit, a developing unit, and a transfer unit is provided.

First, an example of the image forming apparatus according to the present invention will be described with reference to FIG.
In the figure, a charging device (2) is disposed opposite to the photoreceptor (1) of the present invention.
The charging device (2) in the image forming apparatus shown in FIG. 4 is a contact charging method using a roller charging device. In the present invention, the charging device (2) includes a corona charging device, a contact charging device, and a proximity charging device. Any charging device such as (non-contact charging device) can be used. The proximity charging method is a means for charging the charging member and the photosensitive member with a distance of several tens of μm.
However, in the present invention, those that are in contact with or close to the photosensitive member (1) are preferably used from the viewpoint of reduction of ozone generation and power consumption. In particular, in order to prevent contamination of the charging unit, a charging mechanism disposed in the vicinity of the photosensitive member having an appropriate gap between the surface of the photosensitive member and the charging unit is effectively used.

  The effect of the present invention becomes remarkable when the charging means arranged in contact or close proximity is used as described above. As the transfer means, the above charger can be generally used, but a combination of a transfer charger and a separation charger is effective.

  In the contact charging or proximity charging method, a DC voltage or a DC voltage superimposed on an AC voltage is applied to the charging member. Both contact charging and non-contact charging are performed according to Paschen's law, and the charging start voltage Vth is the lowest during contact charging, and the starting voltage Vth increases as Gap increases. In order to set the charging voltage of the photoreceptor (1) to −400 to −800V, a DC voltage of −1000V to −2000V is applied, or a DC voltage of −450 to −900V is applied to 700V to 2000V / 800 to 4500 Hz. Apply alternating voltage (sine wave, triangle wave). The AC voltage is superimposed in order to prevent uneven charging when there is a gap between the photosensitive member and the charging member, and to prevent image unevenness. A high DC voltage is set to a DC voltage obtained by superposing an AC voltage of a Peak to Peak voltage that is twice or more the charging start voltage Vth.

The roller charging member is covered with an elastic member using a SUS round bar of φ5 to φ15 (mm) as a core metal. For elastic members that charge the photoconductor, resistance control materials such as conductive carbon, carbon fiber powder, and ionic conductive agent are added to epichlorohydrin rubber alone or urethane rubber or epichlorohydrin rubber. In which the specific resistance is adjusted to 10 ⁵ to 10 ¹⁴ (Ω · cm) is used. Specifically, the electric resistance of the surface facing the photoconductor between the contact charging member and the non-contact charging member can be changed depending on the charging method.

  The photoconductor (1) uniformly charged by the charging device (2) is then irradiated with image information of a dot pattern of light output from the LD element or LED element array output from the image exposure device (3). Is done. As a result, an electrostatic latent image having a light-dark potential difference is formed on the photoreceptor (1). The light / dark potential difference is preferably at least 250 V, and is preferably 350 to 600 (V).

The electrostatic latent image formed in this way is visualized as a toner image by the developing device (4). A toner visible image is formed by developing with a two-component developer comprising a mixture of toner particles and carrier particles supplied on a developing sleeve which is a developer carrying member.
At the time of developing the latent image, a voltage of an appropriate magnitude or an AC voltage between the exposed portion and the non-exposed portion of the photosensitive member (1) is applied from the voltage applying mechanism (not shown) to the developing sleeve (41). A developing bias with superimposed is applied.

  The carrier is a resin such as polyfluorinated carbon, polyvinyl chloride, or polyvinylidene chloride to improve the chargeability, charging stability, durability, etc. of magnetic powder (magnetic powder) such as iron, ferrite, and nickel. The average particle size of the carrier is about 30 to 80 μm.

The toner includes a pulverized toner obtained by a mechanical pulverization method and a polymerized toner produced chemically.
The pulverized toner is considered to be advantageous for cleaning because it has an irregular shape (average circularity is around 0.9) and has a sharp point. However, since the shapes and particle sizes are not uniform, the transfer efficiency and development fidelity are a little inferior, and the image quality tends to be deteriorated, for example, containing a toner having a small particle size.

  On the other hand, there are suspension polymerization method, dispersion polymerization method, emulsion polymerization method, microcapsule polymerization method, spray drying and the like as means for producing the polymerized toner. For example, in the case of suspension polymerization, the binder resin is produced by homogenizing an additive such as a colorant or a charge control agent, and adding a dispersion medium and a dispersant to polymerize the binder resin. Since the process of the polymerization method is simplified, the manufacturing cost is lower than that of the pulverization method. Moreover, the particle diameters are relatively well aligned, almost spherical (average circularity of 0.95 to 0.995), and the particle diameters are approximately uniform.

  Therefore, it is easy to align the charges uniformly, the image is developed almost faithfully to the latent image, and the transfer efficiency is increased, so that an image excellent in sharpness and high resolution can be reproduced. The average particle size of the toner used is about 4 to 8 μm. However, on the other hand, since the shape is spherical or close to a spherical shape and the cleaning performance is inferior to that of pulverized toner, the cleaning performance becomes important when the spherical toner is used.

  The toner and the carrier are mixed so that the toner concentration is 3 to 8% by weight.

  The toner image developed and visualized is transferred to the transfer target (copy paper) (9) by the transfer means (5). At this time, it is preferable that a potential having a polarity opposite to that of toner charging is applied to the transfer means (5) as a transfer bias. Thereafter, the transfer target (9) is separated from the photoreceptor (1) by the separation device (6), and then discharged as an output image through the fixing device (8).

The toner particles remaining on the latent image carrier are collected by a cleaning unit (7), and the collected toner particles are conveyed to a developing unit and / or a toner supply unit by a toner recycling unit (not shown). And may be reused.
As the cleaning means (7), a rubber cleaning blade, a brush such as a fur brush, a mag fur brush, or the like can be used. In FIG. 4, the cleaning device (7) is of a type in which only the cleaning blade (7-1) is provided, but a cleaning device provided with a cleaning brush can also be used.

  The cleaning brush plays an auxiliary role of the cleaning blade (7-1), and is effective when the amount of toner on the photoreceptor (1) is large. As the cleaning brush, a loop brush and a cut pile brush are known, and it is desirable to use them properly depending on system conditions.

  In order to improve transfer efficiency and cleaning efficiency, a method of forming an image by supplying a lubricant such as a fatty acid metal salt to the surface of the photoreceptor is also effective in order to reduce the surface energy of the photoreceptor. As a means for supplying the low surface energy agent to the surface of the photoreceptor, a method of containing a fatty acid metal salt in the developer or a solid material such as zinc stearate is supplied via a brush roll that also serves as a cleaning means. The method and other known methods are used.

  Conventionally, a full-color image forming apparatus is an image forming apparatus in which four color developing devices including yellow (Y), magenta (M), cyan (C), and black (Bk) are arranged on one photoconductor. Although the copy speed was 3 to 6 (ppm), in recent years, four-tandem image formation in which four copying systems shown in FIG. 4 are incorporated into one image forming apparatus as shown in FIG. Many devices are being used.

  The quadruple tandem image forming apparatus shown in FIG. 5 separates a full-color original into light corresponding to G (green), R (red), and B (blue), and produces yellow (Y) and magenta (M). , Cyan (C), and black (Bk) are used to develop the electrostatic latent image formed on the photosensitive member, and the toner of four colors is transferred onto the intermediate transfer belt, and then a transfer target (copy) Paper) and heat-fixed to make a hard copy. The copying speed is four times that of a conventional full-color image forming apparatus.

  In a full-color image forming apparatus, color reproducibility is particularly important. Therefore, it is necessary to suppress deterioration of toner cleaning property and acceleration of wear by the cleaning blade so that the color reproducibility is not deteriorated due to wear of the photosensitive layer or color mixture. Therefore, it is necessary to sufficiently prevent blade vibration, blade edge distortion, and toner or carrier from entering under the cleaning blade as the frictional resistance between the cleaning blade and the photosensitive member increases.

In addition, in order to obtain a high-quality color image, for example, a solid lubricant such as zinc stearate is supplied to the surface of the photoreceptor by other known methods such as a method of supplying a solid lubricant via a brush roll that also serves as a cleaning unit. Therefore, it is necessary to improve transfer efficiency and cleaning efficiency.
4 and 5, the photoconductor (1) has a drum shape, but may have a sheet shape or an endless belt shape as shown in FIG.

  The photoreceptor of the present invention is used for the photoreceptor (1). The photosensitive member (1) is driven by the driving means (1C), charged by the charging means (2), image exposure by the exposure means (3), development (not shown), transfer by the transfer means (6), and before cleaning. Exposure before cleaning by the exposure means (1B), cleaning by the cleaning means (7), and static elimination by the static elimination means (1A) are repeated. In FIG. 6, light irradiation for pre-cleaning exposure is performed from the support side of the photoconductor (in this case, the support is translucent).

  The above electrophotographic process exemplifies an embodiment of the present invention, and other embodiments are of course possible. For example, in FIG. 6, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side, or image exposure and neutralization light irradiation may be performed from the support side. On the other hand, the light irradiation process is illustrated as image exposure, pre-cleaning exposure, and static elimination exposure. In addition, a pre-transfer exposure, a pre-exposure of image exposure, and other known light irradiation processes are provided to light the photosensitive member. Irradiation can also be performed.

The image forming means described so far may be fixedly incorporated in a copying machine, a facsimile machine, or a printer. Good. A process cartridge is a device (component) that contains a photosensitive member and includes at least one of charging means, image exposure means, developing means, transfer means, fixing means, transfer means, and cleaning means. ).
By integrating these members into a process cartridge that can be integrated into the image forming apparatus, if an abnormality related to these members occurs, the process cartridge can be replaced to immediately recover the failure. Can do. Further, when maintenance is performed, time can be saved, which is advantageous in terms of cost.

  FIG. 7 is a schematic view showing an example of a process cartridge for an image forming apparatus according to the present invention. The photoreceptor of the present invention is used for the photoreceptor (1) and the developing means (4). There are many types of process cartridges and the like, but the one shown in FIG. 7 is an example of a general process cartridge using contact charging means.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. All parts used in the examples, Wath Table all parts. Of the following examples, “Examples 9 to 11, 28 to 30, 39, and 50 to 52” are all “reference examples”.

(Photoreceptor Preparation Example 1)
In a hard glass pot (diameter: 9 cm, 300 ml), 500 parts of φ1 mm zirconia beads, 50 parts of the porous zirconia particles of the porous particle production example 2 so as to be ½ the volume, 0.5 parts of the electron transport compound (A-1) represented and 200 parts of toluene were added, and dispersion was performed at a rotation speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, this liquid was filtered and then dried under reduced pressure at 140 ° C. to obtain porous zirconia particles carrying the electron transporting compound (A-1) on the inner surface.

  As a conductive cylindrical support, an ED tube made of a 3003 series aluminum alloy having a diameter of 60 mm and a length of 352 mm was prepared. On the ED tube, the coating solution for the undercoat layer, the coating solution for the charge generation layer, the coating solution for the charge transport layer, and the coating solution for the protective layer are sequentially applied and dried on the ED tube, thereby the present invention. Photoconductor 1 was obtained.

[Coating liquid for undercoat layer]
Using a hard glass pot (diameter: 15 cm) and 2500 g φ5 mm alumina balls, a mixture having the following composition was rotated at 78 r, p. After being dispersed at m for 72 hours to prepare an undercoat layer coating solution and dip-coated on an aluminum support, it was heat-cured and dried at 130 ° C. for 25 minutes to form a 20 μm undercoat layer.
・ 400 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Super Becamine G-821-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-30 parts of crosslinked styrene-acrylic hollow particles of Production Example 5 of porous particles-30 parts of porous zirconia particles carrying the electron transporting compound (A-1)-600 parts of methyl ethyl ketone

[Coating liquid for charge generation layer]
Into a hard glass pot (diameter: 15 cm), 4500 g of zirconia balls having a diameter of 5 mm, a charge generating substance, polyvinyl butyral, and a solvent are added so that the volume is ½, and the rotational speed is 85 rpm. Then, dispersion was performed for 7 days to prepare a charge generation layer coating solution. This coating solution was dip coated on the undercoat layer and dried by heating at 120 ° C. for 20 minutes to form a charge generation layer.
-36.7 parts of charge generating material represented by the following structural formula

-Polyvinyl butyral 7.34 parts (ESREC BM-1, manufactured by Sekisui Chemical Co., Ltd.)
・ Cyclohexanone 1805 parts ・ Methyl ethyl ketone 773 parts

  The film thickness of the charge generation layer was adjusted so that the transmittance of the charge generation layer at 655 nm was 20%. The transmittance of the charge generation layer is obtained by applying a charge generation layer coating solution of the following composition to an aluminum cylinder wrapped with a polyethylene terephthalate film under the same conditions as the production of the photoreceptor, and the polyethylene without the charge generation layer applied Using a terephthalate film as a comparative control, the transmittance at 655 nm was evaluated with a commercially available spectrophotometer (manufactured by Shimadzu Corporation: UV-3100).

[Coating liquid for charge transport layer]
A charge transport layer coating solution having the following composition was dip coated on the charge generation layer and then dried by heating at 135 ° C. for 25 minutes to form a 30 μm charge transport layer.
-70 parts of charge transport material (D-1) represented by the following structural formula

-100 parts of bisphenol Z polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.)
・ 0.02 part of 1% silicone oil tetrahydrofuran solution (KF-50100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)
・ 730 parts of tetrahydrofuran

[Coating liquid for protective layer]
Using a φ2 mm zirconia ball, vibration mill dispersion was performed for 2 hours to prepare a coating liquid for a filler-dispersed charge transport layer having the following composition. The filler-dispersed charge transport layer coating solution thus obtained was applied onto the charge transport layer by a spray coating method and then dried at 150 ° C. for 20 minutes to form a 5 μm filler-dispersed charge transport layer.
Α-alumina particles (average primary particle size: 0.3 μm) 2 parts (Sumicorundum AA-03, manufactured by Sumitomo Chemical Co., Ltd.)
・ 0.02 part of polycarboxylic acid compound (SYK-P104: manufactured by Big Chemie Japan)
・ Bisphenol Z polycarbonate 4 parts (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.)
Charge transport material (D-1) 3 parts Cyclohexanone 60 parts Tetrahydrofuran 200 parts

  Observe the cross-section of the photoconductor, and use a microscope or SEM to uniformly disperse the hollow particles and porous particles dispersed in the undercoat layer without being destroyed during liquid adjustment or coating. It was confirmed that the electron transporting compound was uniformly supported.

(Photoreceptor preparation example 2)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of the porous alumina particles of the porous particle production example 1, and the following structural formula 0.5 parts of the electron transport compound (A-2) represented and 200 parts of toluene were added, and dispersion was performed at a rotation speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, this liquid was filtered and then dried under reduced pressure at 140 ° C. to obtain porous alumina particles carrying the electron transporting compound (A-2) on the inner surface.

  Photoreceptor 2 was produced in the same manner as Photoreceptor Production Example 1, except that the undercoat layer coating solution in Photoreceptor Production Example 1 was changed to one having the following composition.

[Coating liquid for undercoat layer]
-Titanium oxide 500 parts (TTO-5 (A) average particle size: 0.04 μm, manufactured by Ishihara Sangyo Co., Ltd.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Super Becamine G-821-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-30 parts of crosslinked styrene-acrylic hollow particles of Production Example 5 of porous particles-30 parts of porous alumina particles carrying the electron transporting compound (A-2)-680 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 3)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of porous alumina particles of the porous particle production example 1, and the following structural formula 0.5 part of the electron transporting compound (A-3) represented and 200 parts of toluene were added, and dispersion was performed at a rotational speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, this liquid was filtered and then dried under reduced pressure at 140 ° C. to obtain porous alumina particles carrying the electron transporting compound (A-3) on the inner surface.

  Photoreceptor 3 was prepared in the same manner as Photoreceptor Preparation Example 1 except that the undercoat layer coating solution in Photoreceptor Preparation Example 1 was changed to one having the following composition and a 25 μm undercoat layer was formed.

[Coating liquid for undercoat layer]
-436 parts of zinc oxide (MZ-305S average particle diameter: 0.07 μm, manufactured by Teica)
180 parts of alkyd resin (Beckolite M6401-50, solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
-Block isocyanate resin 120 parts (Bernock B3-867 solid content: 70%, manufactured by Dainippon Ink & Chemicals, Inc.)
-25 parts of crosslinked styrene-acrylic hollow particles of Production Example 5 of porous particles-35 parts of porous alumina particles carrying the electron transporting compound (A-3)-650 parts of methyl ethyl ketone

(Photosensitive member production example 4)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of the porous zirconia particles of the porous particle production example 2 and the following structural formula And 0.5 part of an electron transport compound (A-4) represented by the following formula and 200 parts of toluene were added, and dispersion was performed at a rotational speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, after filtering this liquid, it dried under reduced pressure on 140 degreeC conditions, and obtained the porous zirconia particle which carry | supported the electron transport compound (A-4) on the inner surface.

  Photoreceptor 4 was prepared in the same manner as in Photoreceptor Preparation Example 1 except that the undercoat layer coating solution in Photoreceptor Preparation Example 1 was changed to one having the following composition and a 10 μm undercoat layer was formed.

[Coating liquid for undercoat layer]
210 parts of titanium oxide (ET-300W average particle size: 0.05 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ 70 parts of polyamide resin (AMILAN CM8000, manufactured by Toray Industries, Inc.)
-Cross-linked styrene-acrylic hollow particles 30 parts (SX8782 (P) porosity: 54%, average particle size: 1.1 μm, inner pore size: 0.9 μm, manufactured by JSR)
-30 parts of porous zirconia particles carrying the electron transporting compound (A-4)-1000 parts of methanol-430 parts of 1-propanol

(Photoreceptor Preparation Example 5)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of the porous polyimide particles of Porous Particle Production Example 4 and electron transport properties 0.5 parts of compound (A-1) and 200 parts of toluene were added, and dispersion was performed at a rotation speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, after filtering this liquid, it dried under reduced pressure on 140 degreeC conditions, and obtained the porous polyimide particle which carry | supported the electron transport compound (A-1) on the inner surface.

  Photoreceptor 5 was prepared in the same manner as Photoreceptor Preparation Example 1 except that the undercoat layer coating solution in Photoreceptor Preparation Example 1 was changed to one having the following composition and a 15 μm undercoat layer was formed.

[Coating liquid for undercoat layer]
・ 292 parts of titanium oxide (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
117 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ 82 parts of alkyd resin (Beckolite M6401-50, solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45 parts (Bernock B7-887-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-Cross-linked styrene-acrylic hollow particles 30 parts (SX866 (A) porosity: 30%, average particle diameter: 0.3 μm, inner pore diameter: 0.2 μm, manufactured by JSR)
-30 parts of porous polyimide particles carrying the electron transporting compound (A-1)-523 parts of methyl ethyl ketone

(Photosensitive member preparation example 6)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of the porous polyimide particles of the porous particle production example 4, and the electron transport property so as to be ½ of the volume. 0.5 part of the compound (A-4) and 200 parts of toluene were added, and dispersion was performed at a rotation speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, after filtering this liquid, it dried under reduced pressure on conditions of 140 degreeC, and obtained the porous polyimide particle which carry | supported the electron transport compound (A-4) on the inner surface.

  The photoreceptor 6 was produced in the same manner as in the photoreceptor preparation example 1 except that the undercoat layer coating solution in the photoreceptor preparation example 1 was changed to one having the following composition to form a 25 μm undercoat layer.

[Coating liquid for undercoat layer]
・ 140 parts of zinc oxide (Zincox Super F-1 average particle size: 0.1 μm, manufactured by Hux Itec Corp.)
・ 70 parts of zinc oxide (MZ-305S average particle size: 0.07 μm, manufactured by Teica)
-Alkyd resin 81.7 parts (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45.4 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-Cross-linked styrene-acrylic hollow particles 25 parts (SX866 (A) porosity: 30%, average particle size: 0.3 μm, inner pore diameter: 0.2 μm, manufactured by JSR)
-40 parts of porous polyimide particles carrying the electron transporting compound (A-4)-350 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 7)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of the porous titania hollow particles of the porous particle production example 7, the electron transport The organic compound (A-1) 0.5 part and 200 parts of toluene were added, and dispersion was performed at a rotational speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, after filtering this liquid, it dried under reduced pressure on 140 degreeC conditions, and obtained the porous titania hollow particle which carry | supported the electron transport compound (A-1) on the inner surface.

  Photoreceptor 7 was prepared in the same manner as Photoreceptor Preparation Example 1 except that the undercoat layer coating solution in Photoreceptor Preparation Example 1 was changed to one having the following composition and a 20 μm undercoat layer was formed.

[Coating liquid for undercoat layer]
・ 400 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Super Becamine G-821-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-40 parts of porous titania hollow particles carrying the electron transporting compound (A-1)-600 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 8)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of the porous titania hollow particles of the porous particle production example 3, and the electron 1.0 part of the transporting compound (A-1) and 200 parts of toluene were added, and dispersion was performed at a rotation speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, after filtering this liquid, it dried under reduced pressure on 140 degreeC conditions, and obtained the porous titania hollow particle which carry | supported the electron transport compound (A-1) on the inner surface.

  Photoreceptor 8 was produced in the same manner as in Photoreceptor Production Example 7 except that this undercoat layer coating solution containing porous titania hollow particles was used.

(Photoreceptor Preparation Example 9)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of porous silica hollow particles of the porous particle production example 7 so as to be ½ of the volume, the electron transport The organic compound (A-1) 0.5 part and 200 parts of toluene were added, and dispersion was performed at a rotational speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, after filtering this liquid, it dried under reduced pressure on 140 degreeC conditions, and obtained the porous silica hollow particle which carry | supported the electron transport compound (A-1) on the inner surface.

  Photoreceptor 9 was produced in the same manner as in Photoreceptor Preparation Example 1 except that the undercoat layer coating solution in Photoreceptor Preparation Example 1 was changed to one having the following composition and a 25 μm undercoat layer was formed.

[Coating liquid for undercoat layer]
-436 parts of zinc oxide (MZ-305S average particle diameter: 0.07 μm, manufactured by Teica)
180 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Block isocyanate resin 120 parts (Bernock B3-867 solid content: 70%, manufactured by Dainippon Ink & Chemicals, Inc.)
-25 parts of porous silica hollow particles carrying the electron transporting compound (A-1)-650 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 10)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of porous alumina hollow particles of the porous particle production example 8, and the electron transport so as to be ½ of the volume The organic compound (A-1) 0.5 part and 200 parts of toluene were added, and dispersion was performed at a rotational speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, this liquid was filtered and then dried under reduced pressure at 140 ° C. to obtain porous alumina hollow particles carrying the electron transporting compound (A-1) on the inner surface.

  Photoreceptor 10 was produced in the same manner as in Photoreceptor Preparation Example 1 except that the undercoat layer coating solution in Photoreceptor Preparation Example 1 was changed to one having the following composition and a 15 μm undercoat layer was formed.

[Coating liquid for undercoat layer]
・ 600 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-40 parts of porous alumina hollow particles carrying the electron transporting compound (A-1)-550 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 11)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of porous alumina hollow particles of the porous particle production example 8, and the electron transport so as to be ½ of the volume 1.25 parts of the active compound (A-1) and 200 parts of toluene were added, and dispersion was carried out at a rotational speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, this liquid was filtered and then dried under reduced pressure at 140 ° C. to obtain porous alumina hollow particles carrying the electron transporting compound (A-1) on the inner surface.

  Photoreceptor 11 was produced in the same manner as in Photoreceptor Preparation Example 1 except that the undercoat layer coating solution in Photoreceptor Preparation Example 1 was changed to one having the following composition and a 25 μm undercoat layer was formed.

[Coating liquid for undercoat layer]
・ 140 parts of zinc oxide (Zincox Super F-1 average particle size: 0.1 μm, manufactured by Hux Itec Corp.)
・ 70 parts of zinc oxide (MZ-305S average particle size: 0.07 μm, manufactured by Teica)
-Alkyd resin 81.7 parts (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45.4 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-40 parts of porous thialumina hollow particles carrying the electron transporting compound (A-1)-310 parts of methyl ethyl ketone

(Photoconductor Preparation Example 12)
Using the porous zirconia particles carrying the electron transporting compound (A-1) in the photoreceptor preparation example 1, the undercoat layer coating solution in the photoreceptor preparation example 1 was changed to the following composition, A photoconductor 12 was produced in the same manner as in Photoconductor Production Example 1 except that a pulling layer was formed.

[Coating liquid for undercoat layer]
・ 292 parts of titanium oxide (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
117 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ 82 parts of alkyd resin (Beckolite M6401-50, solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-40 parts of porous zirconia particles carrying the electron transporting compound (A-1)-550 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 13)
Using the porous polyimide particles carrying the electron transporting compound (A-1) in the photoreceptor preparation example 5, the undercoat layer coating liquid in the photoreceptor preparation example 1 was changed to the following composition, A photoconductor 13 was produced in the same manner as in Photoconductor Production Example 1 except that a pulling layer was formed.

[Coating liquid for undercoat layer]
・ 210 parts of zinc oxide (MZ-305S average particle size: 0.07 μm, manufactured by Teica)
-Alkyd resin 81.7 parts (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45.4 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
20 parts of porous polyimide particles carrying the electron transporting compound (A-1) 350 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 14)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, porous silica particles (Godball E-2C, average particle size: 1.1 μm, so as to be ½ the volume thereof, Pore diameter: 15 nm, manufactured by Suzuki Yushi Kogyo Co., Ltd.) 50 parts, 0.5 part of the electron transporting compound (A-1) and 200 parts of toluene were added, and dispersed for 3 hours at a rotational speed of 50 rpm. To obtain a dispersion. Subsequently, after filtering this liquid, it dried under reduced pressure on 140 degreeC conditions, and obtained the porous silica particle which carry | supported the electron transport compound (A-1) on the inner surface.

  The photoreceptor 14 was produced in the same manner as in the photoreceptor preparation example 1 except that the undercoat layer coating solution in the photoreceptor preparation example 1 was changed to the following composition to form a 20 μm undercoat layer.

[Coating liquid for undercoat layer]
・ 400 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Super Becamine G-821-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-30 parts of porous silica particles carrying the electron transporting compound (A-1)-530 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 15)
Photoconductor 15 was prepared in the same manner as in Photoconductor Preparation Example 7 except that it did not contain an electron transporting compound.

(Photoreceptor Preparation Example 16)
Photoconductor 16 was prepared in the same manner as Photoconductor Preparation 11 except that it did not contain an electron transporting compound.

(Photoreceptor Preparation Example 17)
Photoconductor 17 was prepared in the same manner as Photoconductor Preparation Example 4 except that it did not contain an electron transporting compound.

(Photoreceptor Preparation Example 18)
A photoconductor 18 was produced in the same manner as in the photoconductor production example 10 except that the thickness of the undercoat layer in the photoconductor production example 10 was changed from 15 μm to 3.5 μm.

(Photoreceptor Preparation Example 19)
Using the porous alumina hollow particles carrying the electron transporting compound (A-1) in Photoreceptor Preparation Example 10, the coating solution for the undercoat layer was changed to the following composition, and the undercoat layer of 3.5 μm was formed. A photoconductor 19 was produced in the same manner as in Photoconductor Production Example 1 except for the formation.

[Coating liquid for undercoat layer]
・ 400 parts of titanium oxide (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-30 parts of porous alumina particles carrying the electron transporting compound (A-1)-413 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 20)
Using the porous zirconia particles carrying the electron transporting compound (A-1) in Preparation Example 1 of the photoreceptor, the undercoat layer coating solution was changed to the following composition to form an undercoat layer of 1.2 μm. A photoconductor 20 was produced in the same manner as in Photoconductor Production Example 1 except that.

[Coating liquid for undercoat layer]
210 parts of titanium oxide (TTO-5 (A), average particle size: 0.04 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ 70 parts of polyamide resin (AMILAN CM8000, manufactured by Toray Industries, Inc.)
-30 parts of porous zirconia particles carrying the electron transporting compound (A-1)-700 parts of methanol-300 parts of 1-propanol

(Photoconductor Preparation Example 21)
In Photoconductor Preparation Example 12, the same procedure as in Photoconductor Preparation Example 12 was followed, except that the undercoat layer coating solution did not contain porous zirconia particles carrying the electron transporting compound (A-1). Thus, a photoreceptor 21 was produced.

[Coating liquid for undercoat layer]
・ 292 parts of titanium oxide (CR-EL, average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
117 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
-82 parts alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-4 parts of the electron transporting compound (A-1)-480 parts of methyl ethyl ketone

(Photoconductor Preparation Example 22)
In the photoreceptor preparation example 3, except that it was changed to a coating liquid for an undercoat layer having the following composition not containing porous alumina particles supporting the crosslinked styrene-acrylic hollow particles and the electron transporting compound (A-3), Photoconductor 22 was prepared in the same manner as in Photoconductor Preparation Example 3.

[Coating liquid for undercoat layer]
-436 parts of zinc oxide (MZ-305S average particle size: 0.07 μm, manufactured by Teica)
180 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Block isocyanate resin 120 parts (Bernock B3-867 solid content: 70%, manufactured by Dainippon Ink & Chemicals, Inc.)
-4.5 parts of the electron transporting compound (A-3)-650 parts of methyl ethyl ketone

(Photoconductor Preparation Example 23)
Photosensitive member preparation example 19 is the same as photosensitive member preparation example 19 except that the coating liquid for the undercoat layer does not contain porous alumina hollow particles carrying the electron transporting compound (A-1). Thus, a photoreceptor 23 was produced.

[Coating liquid for undercoat layer]
・ 400 parts of titanium oxide (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-6 parts of the electron transporting compound (A-1)-500 parts of methyl ethyl ketone

(Photoconductor Preparation Example 24)
Photoconductor 24 was prepared in the same manner as in Photoconductor Preparation Example 20 except that it did not contain porous zirconia particles carrying the electron transporting compound (A-1).

[Coating liquid for undercoat layer]
210 parts of titanium oxide (TTO-5 (A), average particle size: 0.04 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ 70 parts of polyamide resin (AMILAN CM8000, manufactured by Toray Industries, Inc.)
-2.1 part of said electron transport compound (A-1)-600 parts of methanol-257 parts of 1-propanol

(Photoconductor Preparation Example 25)
In photoconductor preparation example 6, crosslinked styrene-acrylic hollow particles (SX866 (A) porosity: 30%, average particle size: 0.3 μm, inner pore size: 0.2 μm, manufactured by JSR), and electron transporting compound A photoconductor 25 was produced in the same manner as in Photoconductor Production Example 6 except that the undercoat layer coating solution containing the following composition not containing porous polyimide particles carrying (A-4) was used.

[Coating liquid for undercoat layer]
・ 140 parts of zinc oxide (Zincox Super F-1 average particle size: 0.1 μm, manufactured by Hux Itec Corp.)
・ 70 parts of zinc oxide (MZ-305S average particle size: 0.07 μm, manufactured by Teica)
・ Alkyd resin 81.7 parts (Beckolite M6401-50, solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45.4 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-4.2 parts of said electron transport compound (A-4)-300 parts of methyl ethyl ketone

(Photoconductor Preparation Example 26)
In Photoconductor Preparation Example 4, cross-linked styrene-acrylic hollow particles (SX8782 (P) porosity: 54%, average particle size: 1.1 μm, inner pore size: 0.9 μm, manufactured by JSR), and electron transporting compound A photoconductor 26 was produced in the same manner as in Photoconductor Production Example 4, except that the undercoat layer coating solution containing the following composition containing no porous zirconia particles carrying (A-4) was used.

[Coating liquid for undercoat layer]
・ Titanium oxide 50 parts (ET-500W average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ Titanium oxide 50 parts (ET-300W average particle size: 0.05 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ 33 parts of polyamide resin (AMILAN CM8000, manufactured by Toray Industries, Inc.)
-1 part of the electron transporting compound (A-4)-800 parts of methanol-343 parts of 1-propanol

(Photoconductor Preparation Example 27)
In Photoconductor Preparation Example 1, porous zirconia particles supporting crosslinked styrene-acrylic hollow particles and an electron transporting compound (A-1) were replaced with solid silicone resin particles (Tospearl 120, average particle size: 2). Photoconductor 27 was prepared in the same manner as in Photoconductor Preparation Example 1 except that the undercoat layer coating solution was changed to 0.0 μm (manufactured by GE Toshiba Silicone).

[Coating liquid for undercoat layer]
・ 400 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Super Becamine G-821-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
・ 30 parts of silicone resin particles (Tospearl 120 average particle size: 2.0 μm, manufactured by GE Toshiba Silicones)
-4 parts of the electron transporting compound (A-1)-520 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 28)
In Photoconductor Preparation Example 3, porous alumina particles carrying crosslinked styrene-acrylic hollow particles and an electron transporting compound (A-3) were replaced with solid silicone resin particles (Tospearl 120, average particle size: 2). Photoconductor 28 was prepared in the same manner as Photoconductor Preparation Example 3 except that the undercoat layer coating solution was changed to 0.0 μm (GE Toshiba Silicone).

[Coating liquid for undercoat layer]
-436 parts of zinc oxide (MZ-305S average particle diameter: 0.07 μm, manufactured by Teica)
180 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
-Block isocyanate resin 120 parts (Bernock B3-867 solid content: 70%, manufactured by Dainippon Ink & Chemicals, Inc.)
・ 44 parts of silicone resin particles (Tospearl 120 average particle size: 2.0 μm, manufactured by GE Toshiba Silicones)
-4.4 parts of said electron transport compound (A-3)-650 parts of methyl ethyl ketone

(Photoconductor Preparation Example 29)
Photosensitive member preparation example 19 is the same as photosensitive member preparation example 19 except that the coating liquid for the undercoat layer does not contain porous alumina hollow particles carrying the electron transporting compound (A-1). Thus, a photoreceptor 29 was produced.

[Coating liquid for undercoat layer]
・ 400 parts of titanium oxide (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 413 parts

(Photoreceptor Preparation Example 30)
In the photoreceptor preparation example 5, except that it was changed to a coating liquid for an undercoat layer having the following composition not containing porous polyimide particles supporting the crosslinked styrene-acrylic hollow particles and the electron transporting compound (A-1), Photoreceptor 30 was produced in the same manner as in Photoreceptor Production Example 5.

[Coating liquid for undercoat layer]
・ 292 parts of titanium oxide (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
117 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
-82 parts alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 523 parts

  Photoconductor No. 1 produced as described above. 1 to 30 are shown in Table 1.

Next, a production example of the developer is shown below.
(Example of core particle production)
Manganese and iron oxides are mixed, wet milled and dispersed in water for 48 hours using a ball mill, dried, and calcined at 850 ° C. for 1 hour in a weak reducing atmosphere in an electrothermal atmosphere firing furnace. Was done.
Wet pulverization was performed by filling 10 vol. Of zirconia balls as a pulverization medium with 30 vol% of the ball mill pot volume, and filling the oxide slurry adjusted to a solid content of 25% with 20 vol% of the ball mill pot volume.
Subsequently, the obtained calcined product was wet-ground and dispersed in water again for 24 hours under the same conditions to obtain a manganese iron composite oxide slurry.
To this slurry, polyvinyl alcohol and a dispersant were added as a binder, granulated and dried using a spray dryer, and classified using an ultrasonic vibration sieve to prepare granulated particles.
The obtained granulated particles were subjected to main firing at 1200 ° C. for 4 hours in a weak reducing atmosphere in an electrothermal atmosphere firing furnace to obtain manganese ferrite particles.
Furthermore, the obtained manganese ferrite particles were classified using an ultrasonic vibration sieve to obtain core material particles.

[Example of carrier production]
To a toluene diluted mixture (solid content: 20 wt%) containing 100 parts of a silicone resin (SR2411, manufactured by Toray Dow Corning Silicone Co., Ltd.) and 50 parts of an acrylic resin, γ- (2-aminoethyl) aminopropyltrimethoxysilane ( 2.0 parts of SH 6020P (Toray Dow Corning Silicone Co., Ltd.) was added, and 150 parts of toluene was further added to obtain carrier coating layer coating solution 1.
Next, the carrier coating layer coating solution 1 was applied to the core material particles at a rate of 50 g / min in an atmosphere at 80 ° C. using a fluid bed type coating apparatus. Furthermore, it heated at 200 degreeC for 2 hours, and obtained the carrier of weight average particle diameter: 35.5micrometer and carrier coating layer film thickness: 0.6micrometer.
The thickness of the carrier coating layer was adjusted by the amount of the coating solution, and the thickness was measured by crushing the carrier and observing the cross section with a scanning electron microscope.

  Next, as an example, a manufacturing example of cyan toner is shown below.

(Production example of polyester for addition)
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube, 690 parts of bisphenol A ethylene oxide 2-mole adduct and 230 parts of terephthalic acid were subjected to polycondensation at 210 ° C. for 10 hours under normal pressure, and then reduced in pressure to 10 to 15 mmHg. And then cooled to 160 ° C., 18 parts of phthalic anhydride was added thereto and reacted for 2 hours to obtain unmodified polyester (a) (weight average molecular weight Mw: 85000).

(Prepolymer production example)
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 800 parts of bisphenol A ethylene oxide 2-mole adduct, 160 parts of isophthalic acid, 60 parts of terephthalic acid, and 2 parts of dibutyltin oxide were placed at normal pressure. The mixture was reacted at 8 ° C. for 8 hours, further reacted for 5 hours while dehydrating at a reduced pressure of 10 to 15 mmHg, cooled to 160 ° C., 32 parts of phthalic anhydride was added thereto, and reacted for 2 hours. Next, the mixture was cooled to 80 ° C. and reacted with 170 parts of isophorone diisocyanate in ethyl acetate for 2 hours to obtain an isocyanate group-containing prepolymer (Mw: 35000).

(Production example of ketimine compound)
In a reaction vessel equipped with a stirring bar and a thermometer, 30 parts of isophoronediamine and 70 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain a ketimine compound.

[Toner preparation example]
In a beaker, 14.3 parts of the above prepolymer, 55 parts of polyester (a), and 78.6 parts of ethyl acetate were stirred and dissolved. Subsequently, 10 parts of rice WAX (melting point: 83 ° C.) as a release agent and 4 parts of copper phthalocyanine blue pigment were added, and the mixture was stirred at 12000 rpm for 20 minutes at 40 ° C. using a TK homomixer. It grind | pulverized at 20 degreeC by the bead mill for 40 minutes. This is a toner material oil dispersion.
In a beaker, 306 parts of ion exchange water, 265 parts of tricalcium phosphate 10% suspension, and 0.2 part of sodium dodecylbenzenesulfonate were added, and the above-mentioned aqueous dispersion was added to this aqueous dispersion while stirring at 12000 rpm with a TK homomixer. Toner material oil dispersion and 2.7 parts of ketimine compound were added, and urea reaction was continued while stirring.
After removing the organic solvent from the dispersion (viscosity: 3500 mP · s) under reduced pressure at a temperature of 50 ° C. or less within 1.0 hour under reduced pressure, it is filtered, washed and dried, then air-classified, Toner base particles (1) were obtained.
Next, 100 parts of the obtained base particles and 0.25 part of a charge control agent (Bontron E-84 manufactured by Orient Chemical Co., Ltd.) were charged into a Q-type mixer (Mitsui Mining Co., Ltd.), and the peripheral speed of the turbine blades was adjusted to 50 m / The mixing process was set to sec. In this case, the mixing operation was performed for 2 minutes, 5 minutes of 1 minute pause, and a total treatment time of 10 minutes.
Further, 0.7 part of hydrophobic silica (H2000, manufactured by Clariant Japan) was added and mixed. In this case, the mixing operation was performed at a peripheral speed of 15 m / sec and 30 seconds of mixing for 1 minute and resting for 5 cycles.
A cyan toner was obtained as described above. This pigment-based colorant average dispersed particle diameter was 5 μm, and the toner circularity was 0.960.

  Each color (black, yellow, magenta, cyan) was prepared using the carrier and toner described above, and adjusted to a toner concentration of 7 wt%.

<Toner particle size>
The weight average particle diameter (D4) and number average particle diameter (Dn) of the toner were measured using a particle size measuring device (“Coulter Counter TAII”; manufactured by Beckman Coulter, Inc.) with an aperture diameter of 100 μm. From these results, (weight average particle diameter (D4) / number average particle diameter (Dn)) was calculated.

<Average circularity>
The suspension containing toner particles obtained in the toner production example is passed through the imaging unit detection zone on the flat plate, the particle image is optically detected by a CCD camera, and the perimeter of the equivalent circle having the same projected area is obtained. The average circularity, which is the value divided by the perimeter of real particles, was evaluated. This value can be measured as an average circularity by a flow type particle image analyzer FPIA-2000. As a specific measurement method, as a dispersant in 100 to 150 ml of water from which impure solids have been removed in advance. A surfactant, preferably alkylbenzene sulfonate, is added in an amount of 0.1 to 0.5 ml, and a sample to be measured is further added in an amount of about 0.1 to 0.5 g. It is obtained by performing dispersion treatment for ˜3 minutes and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of 3000 to 10,000 / μl.

  The photoconductors shown in the above photoconductor production 1, 3, 4, 6-9, 11, 12, 14-16, 18, 19, 21, 28, and 30 are mounted on a process cartridge as shown in FIG. The developer was prepared using the carrier and toner obtained in the developer production example, and mounted on a remodeling machine of imagio MP C7500 (exposure light source: 655 nm semiconductor laser) (manufactured by Ricoh) of reversal development system. A4 plate with a pixel density of 600 dpi x 600 dpi in an environment of humidity (23 ° C, 55% RH), high temperature and high humidity (30 ° C / 90% RH), and low temperature and low humidity (10 ° C / 15% RH). A durability test was performed on 500,000 sheets in total, which was copied and printed on TYPE6000 made by Ricoh Co., Ltd. under the condition of printing 5 sheets at a time using an original with an image area ratio of 6%.

  As the charging means, a charging roller disposed in contact with the photosensitive member was used. As the voltage applied to the charging roller, a peak-to-peak voltage of 1.5 kV and a frequency of 0.9 kHz were selected as AC components. For the DC component, a bias was set so that the charged potential of the photosensitive member at the start of the test was −750 V, and the test was performed without changing these conditions until the end of the test. In this apparatus, no neutralizing means is provided.

The setting conditions are as follows.
・ Development gap (photosensitive member-developing sleeve): 0.35 mm
・ Doctor gap (developing sleeve-doctor): 0.5mm
-Photoconductor linear velocity: 352 mm / sec
・ Charging potential (Vd): -750V
-Potential after exposure of the portion corresponding to the image portion (solid document): -100V
Development bias: DC-550V / AC bias component: 2 KHz, -100 V to -900 V, 50% duty
・ Transfer current: 30μA

  As an evaluation method, photoconductor potential and image evaluation at the start and end of the test were performed. The results are shown in Tables 2 to 4 below.

[Evaluation of electrical characteristics]
The initial dark part potential (VD) and exposed part potential (VL) were measured. As for the exposed portion potential, an electrometer probe was attached to the developing portion of the apparatus shown in FIG. 4 and the surface potential of the photosensitive member was measured after moving to the developing portion after charging and image exposure. Initial setting was performed so that the charging potential (dark portion potential: VD) was −750 V and VL was −100 (V). ΔVD and ΔVL represent the absolute values of the changes in the dark portion potential and the exposure portion potential at the initial stage and after the 500,000-sheet passing test, respectively.
ΔVD = | (Dark part potential at initial time: −750 V) − (Dark part potential after passing 500,000 sheets) |
ΔVL = | (exposure portion potential at initial time: −100 V) − (exposure portion potential after passing 500,000 sheets) |
The half-exposure amount E _1/2 (μJ / cm ² ) indicates the exposure energy required to halve the charged potential of the photoconductor. The smaller the E _1/2 value, the better the sensitivity characteristics. ing.

[Evaluation of afterimage (ghost) image]
As an image pattern for evaluation, an afterimage pattern shown in FIG. 8 was prepared. In FIG. 8, the portion (701) is a white portion, the portion (702) is a black solid portion, the portion (703) is a halftone portion, and the portion (704) is an afterimage resulting from the black solid portion (702). Is the part where appears.
・ Afterimage evaluation method
Ten afterimage evaluation patterns were output, and the 10th sheet was evaluated. For evaluation of the afterimage, a spectral densitometer X-Rite 508 manufactured by X-Rite was used. In the output image, the density obtained by subtracting the density of the halftone part (703) from the density of the part (704) where an afterimage may appear was measured, and an average value ΔID of five points was obtained. When ΔID was 0.02 or more, it was determined that the effects of the present invention were not sufficiently obtained.

[Evaluation of background dirt]
Judgment was made in five stages according to the following criteria by comparison with a stage sample.
5: No background stain was observed, and the image quality was excellent 4: Very little background stain was observed 3: Slight background stain was observed, but there was no practical problem Level 2: Image quality deteriorated Level 1: no problem for practical use.

[Evaluation of interference fringes]
A halftone image was output and the degree of occurrence of interference fringes was visually evaluated. Evaluation was made in three stages according to the following criteria.
○: Not visible at all Δ: Slightly observed level ×: Observed clearly, there is a problem in actual use

[Evaluation of dielectric breakdown]
About the photoreceptor which performed the durability test of 500,000 sheets, the presence or absence of the dielectric breakdown was determined on the following reference | standard.
○: Dielectric breakdown of the photoconductor due to charge leak did not occur. ×: Dielectric breakdown of the photoconductor due to charge leak occurred even in a slight amount.

[Dot reproducibility evaluation]
One-dot image evaluation (outputting an image in which independent dots are written) was performed using the image forming apparatus described above. A one-dot image was observed with an optical microscope, and the clarity of the dot outline was ranked. Evaluation was made in three stages according to the following criteria.
○: Clear image with no abnormalities on the image Δ: Slightly disturbed dot on the image, but no problem level in actual use ×: Discolored dot on the image and unclear image

[Image evaluation]
A full color output image after the end of the 500,000 durability test was comprehensively evaluated.

<Evaluation results>
From the results of Tables 2, 3, and 4, it can be seen that the inclusion of porous particles in the undercoat layer exhibits extremely good characteristics for environmental characteristics, electrostatic characteristics, and ghost images (afterimages).
In addition, when the undercoat layer containing no porous particles was used, the occurrence of cracks due to local stress during film formation was confirmed by comparing the examples in Table 4 with Comparative Examples 22 and 25. It was done.
Furthermore, by including an electron transporting compound together with the porous particles of the present invention, it is excellent in charge retention under any environment, does not increase the residual potential even after repeated use, and is better than the result of half exposure. Sensitivity characteristics.
Among them, particles having a shell having a plurality of pores and having a hollow shape can suppress the generation of interference fringes and are uniformly dispersed in the undercoat layer without eluting the electron transporting compound into the upper layer. Therefore, the charge carriers in the photoconductor are smoothly moved, and the high-sensitivity photoconductor can be mounted on a high-speed machine.

(Photoreceptor Preparation Example 31)
As a conductive cylindrical support, an ED tube made of a 3003 series aluminum alloy having a diameter of 100 mm and a length of 368 mm was prepared. On this ED tube, an undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following composition were sequentially applied and dried to prepare a photoreceptor 31.

[Coating liquid for undercoat layer]
Using a hard glass pot (diameter: 15 cm) and 2500 g of φ5 mm alumina balls, a mixture comprising porous zirconia particles carrying the electron transporting compound (A-1) in photoreceptor preparation example 1 and having the following composition was rotated. Number: Dispersed at 78 rpm for 72 hours to prepare a coating solution for an undercoat layer, dip-coated on an aluminum support, heat-cured and dried at 130 ° C. for 25 minutes, and below 20 μm A pulling layer was formed.
200 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
90 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Block isocyanate resin 60 parts (Bernock B3-867 solid content: 70%, manufactured by Dainippon Ink & Chemicals, Inc.)
-15 parts of crosslinked styrene-acrylic hollow particles of Production Example 5 of porous particles-15 parts of porous zirconia particles carrying the electron transporting compound (A-1)-300 parts of methyl ethyl ketone

[Coating liquid for charge generation layer]
A hard glass pot (diameter: 9 cm, 300 ml) is charged with 300 g of zirconia balls having a diameter of 0.5 mm, a charge generating substance (titanyl phthalocyanine), polyvinyl butyral, and a solvent so that the volume is ½ of the volume. Dispersion was carried out at 1500 rpm for 30 minutes to prepare a charge generation layer coating solution. This coating solution was dip coated on the undercoat layer and dried by heating at 95 ° C. for 10 minutes to form a charge generation layer.
・ Titanyl phthalocyanine 15 parts ・ Polyvinyl butyral 10 parts (ESREC BM-1, manufactured by Sekisui Chemical Co., Ltd.)
・ 280 parts of methyl ethyl ketone

  The film thickness of the charge generation layer was adjusted so that the transmittance of the charge generation layer at 780 nm was 25%. The transmittance of the charge generation layer is determined by applying the charge generation layer coating solution having the above composition to an aluminum cylinder wrapped with a polyethylene terephthalate film under the same conditions as the production of the photoreceptor, and the polyethylene without the charge generation layer applied. Using a terephthalate film as a comparative control, the transmittance at 780 nm was evaluated with a commercially available spectrophotometer (manufactured by Shimadzu Corporation: UV-3100).

[Coating liquid for charge transport layer]
A charge transport layer coating solution having the following composition was dip coated on the charge generation layer and then dried by heating at 135 ° C. for 25 minutes to form a 38 μm charge transport layer.
-70 parts of charge transport material (D-1) used in Photoconductor Preparation Example 1-100 parts of bisphenol Z polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.)
・ 0.02 part of 1% silicone oil tetrahydrofuran solution (KF-50100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)
・ 730 parts of tetrahydrofuran

(Photoconductor Preparation Example 32)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of φ1 mm zirconia beads, 50 parts of the porous acrylic particles of the porous particle production example 6, and the electron transport property so as to be ½ of the volume. 0.5 part of the compound (A-2) and 200 parts of toluene were added, and dispersion was performed at a rotation speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, after filtering this liquid, it dried under reduced pressure on 140 degreeC conditions, and obtained the porous acrylic particle which carry | supported the electron transport compound (A-2) on the inner surface.

  A photoreceptor 32 was produced in the same manner as in the photoreceptor preparation example 31 except that the undercoat layer coating solution in the photoreceptor preparation example 31 was changed to one having the following composition.

[Coating liquid for undercoat layer]
・ 400 parts of zinc oxide (Zincox Super F-1 average particle size: 0.1 μm, manufactured by Hux Itec Corp.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Bernock B7-887-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-Cross-linked styrene-acrylic hollow particles 25 parts (SX8782 (P) porosity: 54%, average particle size: 1.1 μm, inner pore size: 0.9 μm, manufactured by JSR)
-40 parts of porous acrylic particles carrying the electron transporting compound (A-2)-350 parts of methyl ethyl ketone

(Photoconductor Preparation Example 33)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of the porous polyimide particles of the porous particle production example 4, and the electron transport property so as to be ½ of the volume. 0.5 part of the compound (A-3) and 200 parts of toluene were added, and dispersion was performed at a rotational speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, after filtering this liquid, it dried under reduced pressure on 140 degreeC conditions, and obtained the porous polyimide particle which carry | supported the electron transport compound (A-3) on the inner surface.

  A photoreceptor 33 was produced in the same manner as in the photoreceptor preparation example 31 except that the undercoat layer coating solution in the photoreceptor preparation example 31 was changed to the following composition to form a 15 μm undercoat layer.

[Coating liquid for undercoat layer]
・ 292 parts of titanium oxide (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
117 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
-82 parts alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-Crosslinked styrene-acrylic hollow particles 30 parts (SX866 (A) hollow ratio: 30%, average particle size: 0.3 μm, inner pore diameter: 0.2 μm, manufactured by JSR)
-30 parts of porous polyimide particles carrying the electron transporting compound (A-1)-523 parts of methyl ethyl ketone

(Photoconductor Preparation Example 34)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of the porous polyimide particles of the porous particle production example 4, and the electron transport property so as to be ½ of the volume. 0.5 parts of compound (A-4) and 200 parts of toluene were added, and the rotational speed was 50 r. p. Dispersion was performed at m for 3 hours to obtain a dispersion. Subsequently, after filtering this liquid, it dried under reduced pressure on conditions of 140 degreeC, and obtained the porous polyimide particle which carry | supported the electron transport compound (A-4) on the inner surface.

  A photoreceptor 34 was produced in the same manner as in the photoreceptor preparation example 31 except that the undercoat layer coating solution in the photoreceptor preparation example 31 was changed to the following composition to form a 25 μm undercoat layer.

[Coating liquid for undercoat layer]
・ 140 parts of zinc oxide (Zincox Super F-1 average particle size: 0.1 μm, manufactured by Hux Itec Corp.)
・ 70 parts of zinc oxide (MZ-305S average particle size: 0.07 μm, manufactured by Teica)
-Alkyd resin 81.7 parts (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45.4 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-Cross-linked styrene-acrylic hollow particles 15 parts (SX866 (A) hollow ratio: 30%, average particle size: 0.3 μm, inner pore diameter: 0.2 μm, manufactured by JSR)
-10 parts of porous polyimide particles carrying the electron transporting compound (A-4)-350 parts of methyl ethyl ketone

(Photoconductor Preparation Example 35)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of porous alumina hollow particles of the porous particle production example 8, and the electron transport so as to be ½ of the volume The organic compound (A-1) 0.5 part and 200 parts of toluene were added, and dispersion was performed at a rotational speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, this liquid was filtered and then dried under reduced pressure at 140 ° C. to obtain porous alumina hollow particles carrying the electron transporting compound (A-1) on the inner surface.
A photoreceptor 35 was produced in the same manner as in the photoreceptor preparation example 31 except that the undercoat layer coating liquid in the photoreceptor preparation example 31 was changed to the following composition to form a 20 μm undercoat layer.

[Coating liquid for undercoat layer]
200 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
90 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Block isocyanate resin 60 parts (Bernock B3-867 solid content: 70%, manufactured by Dainippon Ink & Chemicals, Inc.)
-15 parts of porous alumina hollow particles carrying the electron transporting compound (A-1)-300 parts of methyl ethyl ketone

(Photoconductor Preparation Example 36)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of porous alumina hollow particles of the porous particle production example 8, and the electron transport so as to be ½ of the volume The organic compound (A-1) (0.75 part) and toluene (200 parts) were added, and the dispersion was performed at a rotational speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, this liquid was filtered and then dried under reduced pressure at 140 ° C. to obtain porous alumina hollow particles carrying the electron transporting compound (A-1) on the inner surface.

  A photoreceptor 36 was produced in the same manner as in the photoreceptor preparation example 31 except that the undercoat layer coating solution in the photoreceptor preparation example 31 was changed to the following composition to form a 20 μm undercoat layer.

[Coating liquid for undercoat layer]
・ 400 parts of zinc oxide (Zincox Super F-1 average particle size: 0.1 μm, manufactured by Hux Itec Corp.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-40 parts of porous alumina hollow particles carrying the electron transporting compound (A-1)-450 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 37)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of porous alumina hollow particles of the porous particle production example 8, and the electron transport so as to be ½ of the volume 1 part of the active compound (A-1) and 200 parts of toluene were added, and dispersion was carried out at a rotational speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, this liquid was filtered and then dried under reduced pressure at 140 ° C. to obtain porous alumina hollow particles carrying the electron transporting compound (A-1) on the inner surface.

  A photoreceptor 37 was produced in the same manner as in the photoreceptor preparation example 31 except that the undercoat layer coating solution in the photoreceptor preparation example 31 was changed to the following composition to form a 15 μm undercoat layer.

[Coating liquid for undercoat layer]
・ 292 parts of titanium oxide (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
117 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ 82 parts of alkyd resin (Beckolite M6401-50, solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-41 parts of porous alumina hollow particles carrying the electron transporting compound (A-1)-523 parts of methyl ethyl ketone

(Photoconductor Preparation Example 38)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of porous alumina hollow particles of the porous particle production example 8, and the electron transport so as to be ½ of the volume The organic compound (A-1) (1.25 parts) and toluene (200 parts) were added, and dispersion was performed at a rotational speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, this liquid was filtered and then dried under reduced pressure at 140 ° C. to obtain porous alumina hollow particles carrying the electron transporting compound (A-1) on the inner surface.

  A photoreceptor 38 was produced in the same manner as in the photoreceptor preparation example 31 except that the undercoat layer coating solution in the photoreceptor preparation example 31 was changed to the following composition to form a 25 μm undercoat layer.

[Coating liquid for undercoat layer]
・ 140 parts of zinc oxide (Zincox Super F-1 average particle size: 0.1 μm, manufactured by Hux Itec Corp.)
・ 70 parts of zinc oxide (MZ-305S average particle size: 0.07 μm, manufactured by Teica)
・ Alkyd resin 81.7 parts (Beckolite M6401-50, solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45.4 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-21 parts of porous alumina hollow particles carrying the electron transporting compound (A-1)-250 parts of methyl ethyl ketone

(Photoconductor Preparation Example 39)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of zirconia beads having a diameter of 1 mm, 50 parts of porous alumina particles of the porous particle production example 1, and the electron transport property so as to be ½ of the volume. 1.25 parts of compound (A-1) and 200 parts of toluene were added, and dispersion was carried out at a rotation speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, after filtering this liquid, it dried under reduced pressure on conditions of 140 degreeC, and obtained the porous alumina particle which carry | supported the electron transport compound (A-1) on the inner surface.

  A photoreceptor 39 was produced in the same manner as in the photoreceptor preparation example 31 except that the undercoat layer coating solution in the photoreceptor preparation example 31 was changed to the following composition to form a 15 μm undercoat layer.

[Coating liquid for undercoat layer]
・ 292 parts of titanium oxide (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
117 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
-Alkyd resin 122.5 parts (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
・ 68 parts of melamine resin (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-30 parts of porous alumina particles carrying the electron transporting compound (A-1)-500 parts of methyl ethyl ketone

(Photoconductor Preparation Example 40)
In a hard glass pot (diameter: 9 cm, 300 ml), 550 parts of φ1 mm zirconia beads, 50 parts of the porous acrylic particles of the porous particle production example 6, and the electron transport property so as to be ½ of the volume. 1.25 parts of compound (A-1) and 200 parts of toluene were added, and dispersion was carried out at a rotation speed of 50 rpm for 3 hours to obtain a dispersion. Subsequently, after filtering this liquid, it dried under reduced pressure on 140 degreeC conditions, and obtained the porous acrylic particle which carry | supported the electron transport compound (A-1) on the inner surface.

  A photoreceptor 39 was produced in the same manner as in the photoreceptor preparation example 31 except that the undercoat layer coating solution in the photoreceptor preparation example 31 was changed to the following composition and a 10 μm undercoat layer was formed.

[Coating liquid for undercoat layer]
・ Titanium oxide 50 parts (ET-500W average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ Titanium oxide 50 parts (ET-300W average particle size: 0.05 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ 33 parts of polyamide resin (AMILAN CM8000, manufactured by Toray Industries, Inc.)
-30 parts of porous acrylic particles carrying the electron transporting compound (A-1)-800 parts of methanol-343 parts of 1-propanol

(Photoreceptor Preparation Example 41)
Photoconductor 41 was prepared in the same manner as in Photoconductor Preparation Example 35 except that it did not contain an electron transporting compound.

(Photoconductor Preparation Example 42)
A photoreceptor 42 was produced in the same manner as in the photoreceptor preparation example 39 except that the photoreceptor transport example 39 did not contain an electron transporting compound.

(Photoconductor Preparation Example 43)
In the photoreceptor preparation example 32, a photoreceptor 43 was prepared in the same manner as in the photoreceptor preparation example 32 except that it did not contain an electron transporting compound.

(Photoreceptor Preparation Example 44)
A photoconductor 44 was produced in the same manner as in the photoconductor production example 37 except that the thickness of the drawing layer was changed from 15 μm to 3.5 μm in the photoconductor production example 37.

(Photoconductor Preparation Example 45)
In the photoreceptor preparation example 40, a photoreceptor 45 was prepared in the same manner as the photoreceptor preparation example 40 except that the thickness of the pulling layer was changed from 10 μm to 1.2 μm.

(Photoconductor Preparation Example 46)
In the photoreceptor preparation example 34, a photoreceptor 46 was prepared in the same manner as the photoreceptor preparation example 34, except that the thickness of the drawing layer was changed from 25 μm to 3.5 μm.

(Photoconductor Preparation Example 47)
In Photoconductor Preparation Example 37, the same procedure as in Photoconductor Preparation Example 37 was followed, except that the undercoat layer coating solution did not contain porous alumina hollow particles carrying the electron transporting compound (A-1). Thus, a photoreceptor 47 was produced.

[Coating liquid for undercoat layer]
・ 292 parts of titanium oxide (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
117 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
-82 parts alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-8.2 parts of said electron transport compound (A-1)-523 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 48)
In Photoconductor Preparation Example 44, the same procedure as in Photoconductor Preparation Example 44 was followed, except that the undercoat layer coating solution did not contain porous alumina hollow particles carrying the electron transporting compound (A-1). Thus, a photoreceptor 48 was produced.

[Coating liquid for undercoat layer]
・ 292 parts of titanium oxide (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
117 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ 82 parts of alkyd resin (Beckolite M6401-50, solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-4 parts of the electron transporting compound (A-1)-523 parts of methyl ethyl ketone

(Photoconductor Preparation Example 49)
In Photoconductor Preparation Example 36, the same procedure as in Photoconductor Preparation Example 36 was followed, except that the undercoat layer coating solution did not contain porous alumina hollow particles carrying the electron transporting compound (A-1). Thus, a photoreceptor 49 was produced.

[Coating liquid for undercoat layer]
・ 400 parts of zinc oxide (Zincox Super F-1 average particle size: 0.1 μm, manufactured by Hux Itec Corp.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
-6 parts of the electron transporting compound (A-1)-450 parts of methyl ethyl ketone

(Photoreceptor Preparation Example 50)
In Photoconductor Preparation Example 35, the procedure is the same as Photoconductor Preparation Example 35 except that the coating solution is used for an undercoat layer and does not contain porous alumina hollow particles carrying the electron transporting compound (A-1). Thus, a photoreceptor 50 was produced.

[Coating liquid for undercoat layer]
200 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
90 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Block isocyanate resin 60 parts (Bernock B3-867 solid content: 70%, manufactured by Dainippon Ink & Chemicals, Inc.)
-2 parts of the electron transporting compound (A-1)-300 parts of methyl ethyl ketone

(Photoconductor Preparation Example 51)
In the photoreceptor preparation example 40, the same procedure as in the photoreceptor preparation example 40 was conducted except that the coating liquid for the undercoat layer did not contain porous acrylic particles carrying the electron transporting compound (A-1). Thus, a photoreceptor 51 was produced.

[Coating liquid for undercoat layer]
・ Titanium oxide 50 parts (ET-500W average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ Titanium oxide 50 parts (ET-300W average particle size: 0.05 μm, manufactured by Ishihara Sangyo Co., Ltd.)
・ 33 parts of polyamide resin (AMILAN CM8000, manufactured by Toray Industries, Inc.)
-1 part of the electron transporting compound (A-1)-800 parts of methanol-343 parts of 1-propanol

(Photoreceptor Preparation Example 52)
In Photoconductor Preparation Example 31, porous zirconia particles carrying crosslinked styrene-acrylic hollow particles and an electron transporting compound (A-1) were replaced with solid silicone resin particles (Tospearl 120 average particle size: 2. Photoconductor 52 was prepared in the same manner as Photoconductor Preparation Example 31, except that the undercoat layer coating solution was changed to 0 μm, manufactured by GE Toshiba Silicone Co., Ltd.

[Coating liquid for undercoat layer]
200 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
90 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Block isocyanate resin 60 parts (Bernock B3-867 solid content: 70%, manufactured by Dainippon Ink & Chemicals, Inc.)
-Silicone resin particles 15 parts (Tospearl 120 average particle size: 2.0 μm GE manufactured by Toshiba Silicones)
-2 parts of the electron transporting compound (A-1)-300 parts of methyl ethyl ketone

(Photoconductor Preparation Example 53)
In Photoconductor Preparation Example 32, crosslinked styrene-acrylic hollow particles (SX8782 (P) hollow ratio: 54%, average particle size: 1.1 μm, inner pore size: 0.9 μm, manufactured by JSR) and an electron transporting compound ( A-1) -supported porous acrylic particles were changed to solid silicone resin particles (Tospearl 120 average particle size: 2.0 μm, manufactured by GE Toshiba Silicone), and the coating solution for undercoat layer of the following composition A photoconductor 53 was produced in the same manner as in Photoconductor Production Example 32, except for changing to.

[Coating liquid for undercoat layer]
・ 400 parts of zinc oxide (Zincox Super F-1 average particle size: 0.1 μm, manufactured by Hux Itec Corp.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
・ 40 parts of silicone resin particles (Tospearl 120 average particle size: 2.0 μm GE manufactured by Toshiba Silicones)
-12 parts of the electron transport compound (A-2)-350 parts of methyl ethyl ketone

(Photoconductor Preparation Example 54)
In Photoconductor Preparation Example 44, the same procedure as in Photoconductor Preparation Example 44 was followed, except that the undercoat layer coating solution did not contain porous alumina hollow particles carrying the electron transporting compound (A-1). Thus, a photoreceptor 54 was produced.

[Coating liquid for undercoat layer]
・ 292 parts of titanium oxide (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
117 parts of titanium oxide (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
-82 parts alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 45 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 523 parts

(Photoreceptor Preparation Example 55)
In Photoconductor Preparation Example 36, the same procedure as in Photoconductor Preparation Example 36 was followed, except that the undercoat layer coating solution did not contain porous alumina hollow particles carrying the electron transporting compound (A-1). Thus, a photoreceptor 55 was produced.

[Coating liquid for undercoat layer]
・ 400 parts of zinc oxide (Zincox Super F-1 average particle size: 0.1 μm, manufactured by Hux Itec Corp.)
120 parts of alkyd resin (Beckolite M6401-50 solid content: 50%, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 66.7 parts (Bernock B7-887-60 solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 400 parts

  As described above, the photosensitive member Nos. Tables 5 to 55 are shown in Table 5.

The above-mentioned photoreceptor No. 31 to 55 are mounted on a process cartridge as shown in FIG. 8, the developer is adjusted using the carrier and toner obtained in the developer production example, and the reversal development type image MP1100 (exposure light source: 780 nm semiconductor) Laser) (manufactured by Ricoh Co., Ltd.), environment of normal temperature and humidity (23 ° C, 55% RH), high temperature and high humidity (30 ° C / 90% RH), low temperature and low humidity (10 ° C / 15% RH) Under the A4 size, using a manuscript with a pixel density of 600 dpi x 600 dpi and an image area ratio of 6%, a total of 1.5 million sheets can be copied and printed on TYPE6000 made by Ricoh under the condition of printing 5 sheets at a time. A test was conducted.
As an evaluation method, the amount of change in the photoreceptor potential at the start and end of the test, the afterimage after the test, and the output image after the durability test were comprehensively evaluated. The results are shown in Table 6. Based on the above-mentioned criteria, the photoreceptor potential and afterimage at the start and end of the test were also evaluated, and the image evaluation at the end of the test was comprehensively performed. The results are also shown in Table 6.

As the charging means, a charging roller disposed close to the photosensitive member was used.
As the voltage applied to the charging roller, a peak-to-peak voltage of 1.5 kV and a frequency of 0.9 kHz were selected as AC components. For the DC component, a bias was set such that the charged potential of the photosensitive member at the start of the test was −750 V, and the test was performed under this charging condition until the end of the test.
The conditions are as follows.
・ Development gap (photosensitive member-developing sleeve): 0.35 mm
・ Doctor gap (developing sleeve-doctor): 0.5mm
-Photoconductor linear velocity: 200 mm / sec
・ Charging potential (Vd): -750V
-Potential after exposure of the portion corresponding to the image portion (solid document): -100V
Development bias: DC-500V / AC bias component: 2KHz, -100V to -900V, 50% duty
Transfer current: 120 μA

<Evaluation results>
Comparison of Tables 2, 3, 4 and Table 6 shows that even in a high-sensitivity photoconductor having different charge generation materials, by adding porous particles to the undercoat layer, environmental characteristics, electrostatic characteristics, ghost images (afterimages) It can be seen that very good characteristics are exhibited.
Further, from the comparison between Example 44 and Comparative Example 25, the particles having a shell having a plurality of pores and having a hollow shape more effectively improve functions such as light scattering properties, and generation of interference fringes. Can be suppressed.
Further, from comparison between Example 49 and Example 54, and Example 43 and Example 55, dielectric breakdown was observed in the range where the film thickness of the undercoat layer containing the porous particles of the present invention was 10 μm or more and 40 μm or less. Particularly good characteristics can be maintained in repeated use without causing image defects.
Further, from Example 41 and Comparative Example 28, in the photoreceptor containing solid particles instead of porous particles, the electron transporting compound is supported on the particles even when the addition amount of the electron transporting compound is increased. However, since the segregation into the undercoat layer and the elution into the upper layer are caused, the deterioration of the electrical characteristics is remarkable.
Therefore, an image forming apparatus that has high potential stability and does not generate afterimages (ghosts) even in the case of a high-sensitivity design by the configuration of the present invention containing porous particles capable of supporting an electron transporting compound in the undercoat layer. As shown in FIG.

DESCRIPTION OF SYMBOLS 1 Electrophotographic photosensitive member 2 Charging means 3 Exposure means 4 Development means 5 Transfer means 6 Separation means 7 Cleaning means 7-1 Cleaning blade 8 Fixing means 9 Image receiving medium 21 Conductive support 22 Subbing layer 23 Charge generation layer 24 Charge transport Layer 25 Photosensitive layer 26 Protective layer 1A Static elimination means 1B Pre-cleaning exposure means 1C Driving means

JP 63-167372 A Japanese Patent Laid-Open No. 02-189559 Japanese Patent Laid-Open No. 03-73962 JP 2006-30697 A JP 2006-30700 A JP 2008-8921 A Japanese Patent Laid-Open No. 60-07363 Japanese Laid-Open Patent Publication No. 1-312553 JP 2008-256843 A JP 2004-233563 A

Claims (14)

On a conductive support, an electrophotographic photosensitive member comprising sequentially laminated an undercoat layer and a photosensitive layer, and the multi-porous particles undercoat layer was carrying the electron-transporting compound to the inner surface of the metal An electrophotographic photoreceptor comprising oxide particles and a binder resin.   2. The electrophotographic photosensitive member according to claim 1, wherein the porous particles are porous hollow particles having a shell having a plurality of pores.   3. The electrophotographic photosensitive member according to claim 1, wherein the porous particles are inorganic porous particles containing at least one element selected from the group consisting of titanium, silicon, zirconium, and aluminum. body.   The electrophotographic photosensitive member according to claim 1, wherein the porous particles are crosslinked resin particles. The electron transporting compound is any one of electron transporting compounds represented by the following structural formulas (A-1), (A-2), (A-3), and (A-4). The electrophotographic photosensitive member according to claim 1.

  2. The metal oxide particles are at least one particle selected from the group consisting of titanium oxide, zinc oxide, aluminum oxide, silicon oxide, tin oxide, zirconium oxide, and indium oxide. The electrophotographic photosensitive member according to any one of?   The electrophotographic photosensitive member according to claim 1, wherein the undercoat layer has two or more kinds of metal oxide particles having different average particle diameters.   The electrophotographic photosensitive member according to claim 1, wherein the binder resin is a thermosetting resin.   The electrophotographic photosensitive member according to claim 1, wherein the thickness of the undercoat layer is 10 μm or more and 40 μm or less.   The electrophotographic photosensitive member according to claim 1, wherein the undercoat layer is formed on a conductive cylindrical support having a diameter of 10 mm or more and 200 mm or less.   An image forming apparatus comprising: the electrophotographic photosensitive member according to claim 1; and a charging unit, an image exposure unit, a developing unit, and a transfer unit.   The image forming apparatus according to claim 11, wherein the charging unit is a charging unit that performs charging by a charging member disposed in contact or close to the charging unit.   A process cartridge that can be detachably attached to an image forming apparatus main body, and is selected from the electrophotographic photosensitive member according to claim 1, a charging unit, an image exposure unit, a developing unit, and a transfer unit. A process cartridge comprising at least one means incorporated in a cartridge container.   The process cartridge according to claim 13, wherein the charging unit is a charging unit that performs charging by a charging member disposed in contact with or close to the charging unit.

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