JP2007047467A - Electrophotographic photoreceptor, image forming method using the same, image forming apparatus and process cartridge for image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which maintains excellent environmental stability and high image quality over a prolonged period of time, satisfies both of prevention of leak due to pinholes, etc., and electrical properties even when used for a contact charging device, and is adaptable even to miniaturization; and also to provide an image forming method, an image forming apparatus and a process cartridge for the image forming apparatus. <P>SOLUTION: The electrophotographic photoreceptor is obtained by sequentially stacking at least an undercoat layer, an intermediate layer and a photosensitive layer on a conductive support, wherein the undercoat layer contains two metal oxides different from each other in average particle diameter and a thermosetting resin, and the intermediate layer is based on an organometallic compound. The metal oxides are titanium oxides, and when the average particle diameter of one titanium oxide (T<SB>1</SB>) is represented by D<SB>1</SB>and that of the other titanium oxide (T<SB>2</SB>) by D<SB>2</SB>, a relationship of 0.2<D<SB>2</SB>/D<SB>1</SB>≤0.5 is satisfied. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member, an image forming method, an image forming apparatus, and a process cartridge for an image forming apparatus that can be widely applied to an electrophotographic copying machine, a laser printer, a facsimile, and the like.

  An electrophotographic method using an electrophotographic photosensitive member applied to a copying machine, a laser printer, a facsimile, etc. is to charge the surface of an electrophotographic photosensitive member (hereinafter also referred to as a photosensitive member) in a dark place by corona discharge, for example. 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. The shape of the conductive support is selected depending on 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.
Examples of cylindrical supports include ED pipes that are extruded and drawn, EI pipes that are ironed on the outer surface after extrusion, DI pipes that are manufactured by squeezing and ironing, etc. These materials are used, and all of them do not require surface cutting, so that they are excellent in mass productivity and cost reduction.

  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 increase the accuracy of the outer diameter is effective as a method to completely remove the micro-projections on the surface of the support, but in order to smooth the surface, The feed amount must be reduced, the processing time becomes longer, and an expensive diamond tool is required, so the productivity is low and the demand for low cost cannot be met. 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 general, when an electrophotographic photosensitive member having a photosensitive layer formed on a conductive support is applied to an electrophotographic apparatus that performs line scanning with a laser beam, an interference fringe pattern may appear in an obtained image.
The generation of this kind of interference fringes causes transmission light that has not been absorbed in the photosensitive layer to cause multiple reflections of the laser beam in the photosensitive layer including the support, resulting in interference with incident light on the surface of the photosensitive layer. It is thought to be caused by this.
Therefore, in order to prevent the occurrence of interference fringes, by roughening the surface of the support or by containing metal oxide or silicone resin particles in the undercoat layer, the surface of the undercoat layer is subjected to a roughening treatment, etc. Various methods are being considered.

First, the method of roughening the surface of the support by the above-described cutting is effective as a surface treatment method that removes minute protrusions on the support surface and at the same time prevents interference fringes, but the roughness of the cutting is regular. Therefore, even if the interference fringes disappear, a moire phenomenon due to interference between the cutting stripe and the laser beam occurs.
Therefore, as other methods for roughening the surface of the support, Patent Document 1, Patent Document 2, Patent Document 3 and the like show treatment methods performed in a dry method and a wet method (liquid).

  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 treatment is a method in which abrasive grains are blown onto the surface of the conductive support with air at a high speed to roughen the surface, and the surface roughness can be controlled in the same manner as the wet honing treatment. 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, the abrasive on the support surface must be completely removed even if the cylindrical support outer surface is cleaned and removed. It is difficult. When the photosensitive layer is directly formed on such a support, the contamination on the surface of the support and the nonuniformity of the shape appear as film formation unevenness of the photosensitive layer as they are, and black spots on the white image in the reversal development system, White spots on the black image occur in the forward developing system.

  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 for the purpose of protecting the photosensitive layer from electrical breakdown and improving the charge injection property to the photosensitive layer. 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 an electrophotographic photosensitive member, injection of charges from the conductive support is prevented between the conductive support and the photosensitive layer, the charging property is stabilized, and no residual potential is accumulated. For this purpose, a resin layer called an undercoat layer is laminated.
As materials for forming the undercoat layer, cellulose-based resins are disclosed in Patent Documents 4 and 5, nylon-based resins are disclosed in Patent Documents 6 and 7, and maleic acid-based materials are disclosed in Patent Documents 8 and 9. A resin, and Patent Document 10 disclose a polyvinyl alcohol resin, and Patent Document 11 and Patent Document 12 disclose an undercoat layer formed of a polyamide resin.

  However, these are easily affected by environmental fluctuations that are thought to be caused by ionic impurities in the organic resin, causing characteristic deterioration under high temperature and high humidity and low temperature and low humidity, especially under low temperature and low humidity. The increase in resistance caused an increase in residual potential. Thus, Patent Document 13 and the like disclose an example in which a crosslinkable resin is used for the undercoat layer, but there is a problem that the residual potential increases during repeated use. Was not enough.

  In order to solve this problem, Patent Document 14, Patent Document 15, Patent Document 16, and Patent Document 17 disclose an organic metal compound and an organic resin, Patent Document 18 includes an intermediate layer containing an organic zirconium compound, and Patent Document 19 Discloses a cured film of a zirconium compound and a silane coupling, and Patent Document 20 discloses a preferable degree of curing. As disclosed in these, since the undercoat layer is formed of an inorganic cured film, the electrical characteristics are stable even in environments such as high temperature and high humidity and low temperature and low humidity, and the resistance value greatly increases the residual potential. It does not increase. However, when these intermediate layers are formed on a support, particularly when an organometallic compound is the main component, cracks are likely to occur in the film after coating and drying due to low viscoelasticity. In addition, the technology that contains organic resin to improve this also causes the problem of instability of electrical characteristics due to environmental fluctuations, which is peculiar to organic resin, and further, coating unevenness, gelation, etc. Including that the selection of the resin for preventing the above and the adjustment of the content thereof are indispensable, the above problems have not been completely solved. In addition, since it is difficult to increase the thickness of these techniques, they are easily affected by minute uneven portions present on the surface of the support. For this reason, for example, it is indispensable to apply a surface treatment for preventing interference fringes at the same time as covering defects on the surface of the support by cutting or honing treatment, which increases the manufacturing cost.

A problem of the undercoat layer made of an organometallic compound that is difficult to increase in thickness is that the effect of preventing charge leakage is small.
Recently, instead of a charging device of non-contact charging system such as a corotron, ozone, reducing the generation amount of the NO _X gas, required by the cost of the high voltage power supply, by contacting a roller for such reduction in size of the charger Charging methods for charging are being studied and commercialized. Although contact charging with such a roller can prevent the generation of gases such as ozone and NO _x , the roller is always in contact with the surface of the electrophotographic photosensitive member and further charged with contact, so that pinholes are formed on the surface of the electrophotographic photosensitive member. The problem of a new image defect that has not occurred in an apparatus using a charging process by a conventional corona discharge, such as the occurrence of a defect, has been generated.

  Pinhole leakage may occur due to coating film defects in the photosensitive layer, but in addition to this, conductive foreign matter such as foreign matter, dust, carrier powder, etc. generated from members constituting the device during operation of the electrophotographic device May occur because it is easy to form a conductive path between the contact charging device and the photosensitive substrate by contacting or penetrating into the photosensitive member. Therefore, the undercoat layer is required to have a leak prevention property in addition to the above-described electrical characteristics.

On the other hand, in an electrophotographic photosensitive member used in an apparatus using a contact charging method, in order to improve a residual potential increase while concealing a defect of a conductive support, various electrical characteristics can be obtained. Is being studied.
For example, there is one in which metal oxide particles are dispersed in a binder resin, and such an undercoat layer is obtained by applying a coating liquid containing metal oxide particles and a binder resin onto a support and drying it. It is formed by.

  Patent Document 21, Patent Document 22 and Patent Document 23 disclose an undercoat layer in which conductive particles are dispersed. However, 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 photoreceptor, that is, to suppress the increase in residual potential. is there. However, when the resin in the undercoat layer is reduced, the adhesion to the support is deteriorated, and peeling between the support and the undercoat layer is likely to occur due to repeated use. In particular, when a belt-like support that can be flexibly laid out and can be expected to be downsized and improved in durability, the problem becomes significant.

In order to suppress the increase in residual potential, thinning is also an effective means, but pinhole leak may occur in the image forming apparatus having the contact charging means described above.
On the other hand, scumming may occur due to a decrease in charging potential or the like. In order to suppress this scumming, it is necessary 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 smudge 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, the method having both the function of controlling charge injection and the function of adjusting the resistance by containing conductive particles in one layer of the undercoat layer prevents an increase in residual potential, has a good soiling effect, An undercoat layer having excellent environmental stability cannot be obtained.

On the other hand, a technique for laminating an undercoat layer has been proposed.
For example, as proposed in Patent Document 24, Patent Document 25, and the like, a layer containing conductive particles is formed on a conductive support such as aluminum, and the layer containing the conductive particles is further formed. In addition, there has been proposed a method having an undercoat layer having a two-layer structure in which a resin layer having a function of preventing charge injection is formed. 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, as proposed in Patent Document 26, an anodized film is formed on a conductive support such as aluminum, and further, there is a function of preventing charge injection on the anodized film. A resin layer is formed.
The anodic oxide film is generally formed to a thickness of 5 to 6 μm, and it is known that this film thickness is effective by insulating the entire defect portion of the support surface. A large amount of power equipment investment and electrical energy are required, the anodic oxide film is a porous film, requires a sealing treatment, has a long processing time, and therefore has a large surface treatment cost. There was a problem.

However, since these methods all have the function of controlling charge injection in the organic resin layer, the problem of image degradation due to instability of electrical characteristics due to the influence of the environment is inevitable.
As another method, as proposed in Patent Document 27, a layer containing graphite as conductive particles having a flat shape is formed on a conductive support, and an organic resin is formed on the conductive layer. Alternatively, an intermediate layer for controlling charge injection made of a known material such as an organometallic compound is formed. However, there are many problems due to the particle size and shape, especially when excessive unevenness is easily formed, and when the adhesive effect with the support is lowered or the covering effect by the intermediate layer formed thereon is low This greatly affects the film formability of the photosensitive layer. In order to prevent such a problem from occurring, it is indispensable to control the coating solution at a high level such as the particle size and resin selection.

  On the other hand, in an image forming apparatus using a contact charging method, a pinhole leak occurs when there is a defective portion of the photoconductor or when conductive foreign matter such as carrier powder contacts or penetrates the photoconductor. In order to prevent this, a technique for increasing the thickness of the undercoat layer has been proposed in Patent Document 28, Patent Document 29, Patent Document 30, and the like. Further, techniques for improving dispersibility are disclosed in Patent Document 31, Patent Document 32, and the like. In general, metal oxide particles have a strong tendency to agglomerate in a resin solution, and it is difficult to uniformly disperse them. Even if dispersed once, secondary agglomeration and sedimentation occur. For example, only ultrafine particles having a primary particle size of 100 nm or less It was very difficult to form a dispersion film stably.

  Further, since there is a concern about an increase in residual potential due to thickening, it is difficult to form an undercoat layer having an appropriate film resistance. Furthermore, since the adhesiveness to the support becomes insufficient due to the increase in thickness, the need for roughening the support arises, resulting in an increase in cost. This thickening has various problems not only in a small-diameter drum but also in a belt-shaped photoreceptor that can be laid out more flexibly than a drum-shaped photoreceptor and can be expected to be downsized and improved in durability. In other words, the belt-like photosensitive member is subjected to mechanical stresses more than the drum-like photosensitive member during image formation, such as stress due to the curvature of the roller portion generated when contacting the belt driving roller or the like, or stress due to tension during driving or stopping. The load is large and peeling and cracking are likely to occur.

JP 51-58954 A Japanese Patent Laid-Open No. 3-64762 JP 2003-202691 A JP-A-47-6341 JP-A-48-3544 Japanese Patent Laid-Open No. 48-47344 JP-A-52-25638 JP 49-69332 A JP 52-10138 A JP 58-105155 A JP-A-52-25638 JP 58-95351 A Japanese Patent Publication No. 04-31577 JP 58-93062 A JP 2001-51438 A JP 2004-70142 A JP 2004-70144 A JP-A-61-94057 Japanese Patent Laid-Open No. 2-189559 Japanese Patent Application Laid-Open No. 3-73762 JP 58-93063 A JP 59-84257 A JP 59-93453 A Japanese Patent Laid-Open No. 60-111255 JP 60-97363 A Japanese Laid-Open Patent Publication No. 1-312553 JP 2000-181113 A JP 2004-233563 A JP 2004-287027 A JP 2004-198814 A JP 20042266751 A JP 2004-233678 A

  Therefore, the above-mentioned problems of the prior art are extremely important for the high image quality and high durability of recent copying machines and laser printers. The purpose of the present invention is to maintain excellent environmental stability and high image quality over a long period of time. Furthermore, even when used in a contact charging device, it is compatible with leak prevention and electrical characteristics due to pinholes etc., and also supports miniaturization. An electrophotographic photosensitive member, an image forming method, an image forming apparatus, and a process cartridge for the image forming apparatus are provided.

  As a result of repeated studies to achieve the above-mentioned problems, the present inventors have found that an electrophotographic photosensitive member in which at least an undercoat layer, an intermediate layer and a photosensitive layer are sequentially laminated on a conductive support, By containing at least two kinds of metal oxides having different average particle diameters and a thermosetting resin, and the intermediate layer contains an organometallic compound as a main component, the film formability and adhesion are good, and the external It has been found that an electrophotographic photoreceptor can be provided at a low cost, which is not affected by environmental fluctuations, exhibits a low residual potential with little dark decay, that is, a stable development contrast, and which can maintain excellent electrophotographic characteristics over a long period of time. The present invention has been completed. In addition, it is possible to provide an electrophotographic photosensitive member that can be used in a downsized image forming apparatus and an image forming apparatus having a contact charging unit.

That is, the above-mentioned problems are as follows: (1) In an electrophotographic photosensitive member in which at least an undercoat layer, an intermediate layer and a photosensitive layer are sequentially laminated on a conductive support, the undercoat layer is at least an average. An electrophotographic photoreceptor comprising two kinds of metal oxides having different particle sizes and a thermosetting resin, and the intermediate layer containing an organometallic compound as a main component ",
(2) “The metal oxide is titanium oxide, and the average particle diameter of _one titanium oxide (T ₁ ) is (D ₁ ) and the average particle diameter of the other titanium oxide (T ₂ ) is (D ₂ ). The electrophotographic photosensitive member according to item (1), wherein 0.2 <D ₂ / D ₁ ≦ 0.5 is satisfied,
(3) “The average particle diameter (D ₂ ) of the titanium oxide (T ₂ ) is 0.05 μm <D ₂ <0.20 μm, and the weight mixing ratio of (T ₁ ) and (T ₂ ) is 0.2 ≦ T ₂ / (T ₁ + T ₂ ) ≦ 0.8, The electrophotographic photosensitive member according to item (1) or (2),

（式中、ＸはＺｒ、Ｔｉを表し、Ｒはアルキル基を表し、Ｒ’は、有機基を表し、ｍおよびｎは、それぞれ０以上であり、ｍ＋ｎ＝４である。）
（５）「前記中間層が有機金属化合物とシランカップリング剤とを含有することを特徴とする前記第（１）項乃至第（４）項の何れかに記載の電子写真感光体」、
（６）「前記中間層の膜厚が０．０５〜０．５μｍであることを特徴とする前記第（１）項乃至第（５）項の何れかに記載の電子写真感光体」、
（７）「前記下引き層の膜厚が３〜１５μｍであることを特徴とする前記第（１）項乃至第（６）項の何れかに記載の電子写真感光体」、
（８）「前記導電性支持体の表面粗さが十点平均粗さＲｚにおいて０．０５〜１．０μｍであり、かつ最大高さＲｙにおいて０．５〜１．５μｍであることを特徴とする前記第（１）項乃至第（７）項の何れかに記載の電子写真感光体」、 (4) The said intermediate | middle layer contains the polymer produced | generated from the organometallic compound shown by following General formula (1), Any one of said (1) thru | or (3) characterized by the above-mentioned. Electrophotographic photoreceptor ",

(In the formula, X represents Zr, Ti, R represents an alkyl group, R ′ represents an organic group, m and n are each 0 or more, and m + n = 4.)
(5) "The electrophotographic photosensitive member according to any one of (1) to (4) above, wherein the intermediate layer contains an organometallic compound and a silane coupling agent";
(6) "The electrophotographic photosensitive member according to any one of (1) to (5) above, wherein the film thickness of the intermediate layer is 0.05 to 0.5 µm",
(7) “The electrophotographic photosensitive member according to any one of (1) to (6) above, wherein the thickness of the undercoat layer is 3 to 15 μm”,
(8) “The surface roughness of the conductive support is 0.05 to 1.0 μm at the ten-point average roughness Rz, and 0.5 to 1.5 μm at the maximum height Ry. The electrophotographic photosensitive member according to any one of (1) to (7),

(9) "The electrophotographic photosensitive member according to any one of (1) to (8) above, wherein the conductive support is a non-cutting tube made of aluminum or an aluminum alloy",
(10) "The electrophotographic photosensitive member according to any one of (1) to (9) above, wherein the conductive support is a conductive cylindrical support having a diameter of 30 mm or less" ,
(11) This is achieved by “the electrophotographic photosensitive member according to any one of (1) to (8) above, wherein the conductive support is an endless belt”.
(12) “Image formation using at least the electrophotographic photosensitive member according to any one of the items (1) to (11) and a charging unit, an image exposure unit, a development unit, and a transfer unit. Achieved by "method".
(13) This is achieved by “the image forming method according to (12) above, wherein the charging unit is a charging unit that performs charging by a charging member disposed in contact with the charging unit”.
(14) Achieved by “an image forming apparatus comprising at least the electrophotographic photosensitive member according to any one of (1) to (11), a charging unit, an image exposing unit, a developing unit, and a transferring unit”. Is done.

(15) This is achieved by “the image forming apparatus according to (14), wherein the charging unit is a charging unit that performs charging by a charging member arranged in contact”.
(16) “A process cartridge that can be detachably attached to an image forming apparatus main body, the electrophotographic photosensitive member according to any one of (1) to (11), a charging unit, an image exposure unit, This is achieved by a process cartridge characterized in that at least one means selected from developing means, transfer means, fixing means, and cleaning means is incorporated in a cartridge container.
(17) This is achieved by “the process cartridge according to (16), wherein the charging unit is a charging unit that performs charging by a charging member disposed in contact with the charging unit”.
(18) This is achieved by “an image forming apparatus comprising the process cartridge according to (17)”.

The electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member in which at least an undercoat layer, an intermediate layer and a photosensitive layer are sequentially laminated on a conductive support, and the undercoat layer has at least two different average particle diameters. It contains a seed metal oxide and a thermosetting resin, and the intermediate layer contains an organometallic compound as a main component.
In addition, unless otherwise indicated, the average particle diameter of the metal oxide in this invention shows a volume average particle diameter, and was calculated | required with the ultracentrifugal automatic particle size distribution measuring apparatus: CAPA-700 (made by Horiba Seisakusho). is there. At this time, the particle size (Median system) corresponding to 50% of the cumulative distribution was calculated.

As the metal oxide contained in the undercoat layer of the present invention, titanium oxide, zinc oxide, aluminum oxide, silicon oxide, tin oxide, indium oxide and the like that hardly absorb visible light and near infrared light are desirable.
However, if the resistance of the metal oxide is not appropriate, charge injection from the support is promoted and image defects are caused. Therefore, a material having a specific resistance in the range of 10 ² to 10 ¹¹ Ω · cm is preferably used. it can.

The specific resistance of the metal oxide used in the present invention was measured by the following method. Since powders such as metal oxides have different specific resistance values depending on the filling rate, it is necessary to measure them under certain conditions. In the present invention, the specific resistance value of the metal oxide was measured using an apparatus having the same configuration as that of the measuring apparatus disclosed in Japanese Patent Laid-Open No. 5-113688 (FIG. 1). In the measuring device, the electrode area is 4.0 cm ² . Prior to the measurement, a load of 4 kg is applied to the electrode on one side for 1 minute, and the sample amount is adjusted so that the distance between the electrodes is 4 mm. At the time of measurement, the measurement is performed with the upper electrode weight (1 kg) loaded, and the applied voltage is measured at 100V. The area of 10 ⁶ Ω · cm or higher was measured with a HIGH RESISTER METER (Yokogawa Hewlett Packard), and the area below it was measured with a digital multimeter (Fluk). The specific resistance of the titanium oxide used in the present invention was 10 ⁷ to 10 ⁹ Ω · cm.

  The purpose of the metal oxide contained in the undercoat layer is to cover defects on the surface of the support, to prevent moire images, and to improve carrier injection properties of the photosensitive layer. Among these, titanium oxide has appropriate conductivity and is an N-type semiconductive particle having an electron as a conductive carrier, and therefore efficiently blocks hole injection from the support. In addition, the refractive index is higher than that of other metal oxides, and the transmittance of light when used as an undercoat layer is low. Therefore, it is used in the present invention for the reason that the influence on the image from the support is small. As the metal oxide to be obtained, titanium oxide is particularly preferable.

  As the titanium oxide used in the present invention, those obtained in accordance with a production method usually used in industrial production can be used. Reacting the ore with sulfuric acid to make a sulfate solution, clarifying the solution, precipitation of hydrous titanium oxide by hydrolysis, washing of the hydrous titanium oxide, firing, grinding, surface treatment, sulfuric acid method, chlorine method, Although it can be obtained according to production methods such as hydrofluoric acid method, potassium titanium chloride method, aqueous solution of titanium tetrachloride, etc., the chlorine method is more preferable 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.

Titanium oxide has a rutile type and an anatase type due to the difference in crystal structure, and physical properties such as specific gravity, refractive index, and hardness differ depending on the crystal form. In this embodiment, the rutile form is used, but an anatase form may be used, or both may be used in combination. In general, metal oxides 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 used in the invention is desirably 95% or more.

Furthermore, in order to improve various characteristics such as dispersibility improvement, titanium oxide particles can be appropriately used those which have been subjected to surface treatment such as hydrous alumina treatment, hydrous silicon dioxide treatment or zinc oxide treatment. In order to perform a uniform surface treatment, it is also effective to subject the surface of the titanium oxide particles to a plurality of times.
In order to obtain an appropriate specific resistance, it is also effective to provide a conductive coating layer using tin oxide or the like as necessary.

In the present invention, the reason why the particle size ratio and / or the mixing ratio of two types of titanium oxide having a specific particle size forming the undercoat layer is a very important factor is considered as follows.
By containing titanium oxide having a specific range of particle sizes in a specific ratio as in the present invention, the dispersion stability of the coating solution is good and the viscosity of the coating solution can be easily adjusted. Film formation is possible, and image deterioration caused by leakage resistance and increase in residual potential due to repeated use can be suppressed.
When the particle size ratio (D ₂ / D ₁ ) of these two types of titanium oxide exceeds the range of 1/5 <D ₂ / D ₁ ≦ 1/2, that is, in the undercoat layer composed of fine particles. The effect of preventing moire images is low, and when titanium oxide having a large particle size is contained, the titanium oxide particles are likely to settle in the coating liquid, and the dispersibility is deteriorated.

  On the other hand, adhesion is one of the functions required for the undercoat layer. In general, the binder resin mainly has a bonding function between the support and the photosensitive layer or between the support and the intermediate layer. For this reason, when using a small-diameter drum or an endless belt as the support, the undercoat layer does not cause an increase in residual potential due to an increase in the resin content for the purpose of improving adhesion and durability against mechanical loads. It is indispensable to balance sex. In particular, the undercoat layer of the present invention is extremely effective in a belt-shaped photoreceptor that can be laid out more flexibly than a drum-shaped photoreceptor. In addition to loads such as transfer and cleaning means received at the time of image formation, it also applies to mechanical loads such as stress due to the curvature of the roller that occurs when contacting the belt drive roller, etc., and stress due to tension during driving and stopping The occurrence of peeling and cracking can be suppressed.

As described above, the reason why the constitution of the undercoat layer of the present invention has led to the solution of the problem of occurrence of a decrease in adhesiveness or cracks that could not be achieved by the conventional technique is as follows. Since the titanium oxide particles (T ₂ ) with small particle size, which are contained at a specific weight mixing ratio, have the function together with the binder resin, the content of the binder resin causing an increase in residual potential is increased. It is considered that the adhesiveness is remarkably improved by filling the gaps between the minute irregularities on the surface of the support without making it.

In addition, as in the present invention, by containing two types of titanium oxide having a specific particle size at a specific ratio, the space formed in the conventional undercoat layer is made of titanium oxide and a binder resin. Filling and dense film formation are possible, and at the same time, the contact area with the binder resin is increased, so that pinhole leakage that occurs when a high electric field is applied locally can be prevented.
As the binder resin constituting the undercoat layer, a thermosetting resin is particularly effectively used. As described above, 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 necessary. In the present invention, a three-dimensional network structure is formed by using a thermosetting resin, this structure prevents the uptake of water molecules and the like into the coating film, and the undercoat layer has improved film formability. Therefore, there is no sudden drop in resistance under high temperature and high humidity.
This effect is further improved by combining with the metal oxide contained in the specific particle size and mixing ratio described above, and a subbing layer having a structurally dense and low hygroscopic property can be obtained.

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 the thermosetting resin described above has a hydroxyl group, a carboxyl group, and an amino group, it can be crosslinked and cured by containing an appropriate curing agent.
As the curing agent, known curing agents such as melamine resin, polyisocyanate resin, and phenol resin can be used.

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. 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 “Beccozole” series and “Super Beccozole” series manufactured by Dainippon Ink and Chemicals, Inc.
Commercially available melamine resins include, for example, the “Super Becamine” series, which is a butylated melamine resin manufactured by Dainippon Ink & Chemicals, Inc., the “Cymel” series, manufactured by Mitsui Cytec, "Nikarak" series manufactured by Sanwa Chemical Co., Ltd.
Examples of commercially available phenolic resins include “Priorphen” series manufactured by Dainippon Ink and Chemicals, Inc.

  Many of the photosensitive layers used in general organic photoreceptors have been developed as low molecular weight compounds. Since low molecular weight compounds are not film-forming alone, they are usually dispersed and mixed in an inert polymer. Used. For example, in the case of a function-separated type laminated photoreceptor, such a charge transport layer composed of a low-molecular charge transport material and an inert polymer is caused by a development system or a cleaning system when repeatedly used in an electrophotographic process. A decrease in film thickness is caused by wear due to a load on a mechanical photoreceptor surface. In addition, the contact charging device that contacts the charging member with the photosensitive member to charge the surface of the photosensitive member has advantages such as a low power supply and a small amount of ozone generation, but it is more advantageous than conventional corona chargers. , Promote wear. This decrease in film thickness leads to an increase in electric field strength, and the undercoat layer cannot sufficiently block charge injection from the conductive support, so that innumerable black spots are generated in the white background area where images are not originally printed. Phenomenon, that is, the occurrence of scumming, and the image quality becomes remarkable.

  Therefore, in order to suppress soiling caused by charge injection from the support and to maintain stable electrophotographic characteristics that are not affected by environmental fluctuations over a long period of time, an intermediate layer is provided between the undercoat layer and the photosensitive layer. Providing a layer is a very effective means. Furthermore, this technique allows the undercoat layer to have appropriate conductivity, and is a thick film that is expected to prevent pinhole leaks that are likely to occur particularly when used in an image forming apparatus having a contact charging means. Can be realized.

The present invention relates to an electrophotographic photosensitive member in which at least an undercoat layer, an intermediate layer, and a photosensitive layer are sequentially laminated on a conductive support, wherein the undercoat layer has at least two metal oxides having different average particle diameters. And a thermosetting resin, and the intermediate layer contains an organometallic compound as a main component.
Specifically, an intermediate layer mainly composed of an organometallic compound is formed on an undercoat layer composed of two kinds of metal oxides and thermosetting resins that are contained in a specific particle size and mixing ratio. In particular, the structure of the undercoat layer is a very important factor.
In general, an intermediate layer made of an organometallic compound has cracks due to its low viscoelasticity and has a fatal defect in its film formability. This combination can solve the problem of image defects due to poor film formation, and can sufficiently exhibit the excellent environmental stability unique to this inorganic cured film.

As described above, the reason why the configuration of the present invention is extremely effective is considered as follows in order to solve the problem of film formability that the intermediate layer containing the organometallic compound has conventionally had.
In general, when an organometallic compound is used as a main component, there is a concern about the problem of cracks due to large volume shrinkage during film formation. This was included for the purpose of prevention of moire image and surface treatment such as cutting and honing treatment for the purpose of covering defects on the support surface, or for the purpose of adhesion to the intermediate layer and moire image prevention. Although it is inevitable that the uneven portion is present due to the conductive particles in the undercoat layer, this is considered to be caused by having an excessive surface property that induces the occurrence of cracks and the like. On the other hand, the structure of the undercoat layer of the present invention is that the metal oxide and thermosetting resin contained with a specific particle size and mixing ratio realize appropriate filling of the undercoat layer, and The surface characteristics alleviate local stress concentration due to volume shrinkage during the deposition of the intermediate layer. That is, since the undercoat layer of the present invention itself also functions as a buffer layer that absorbs strain generated between the intermediate layer containing the organometallic compound as a main component, generation of cracks and pores is prevented. It can be suppressed. Therefore, the film formability of the intermediate layer of the present invention can be dramatically improved.

As described above, the constitution of the undercoat layer of the present invention is an organic material in which the characteristics that vary depending on the environmental conditions have an adverse effect on the image quality, and further make it difficult to control the coating liquid because it causes problems such as gelation. Without containing a resin, it is possible to achieve both good film formability and electrical characteristics that could not be achieved by conventional techniques.
In addition, a thick undercoat layer having appropriate conductivity has a function of covering a defective portion of a support, preventing moire and preventing pinholes, and both an undercoat layer and an intermediate layer of a thin film formed thereon are provided. It has a function of preventing charge injection from the support that causes soiling without causing accumulation of residual potential. Therefore, among the charges generated in the photosensitive layer by the image exposure, the charges that should flow out to the support side are not trapped in the intermediate layer and the undercoat layer, and the flow of the charges is performed smoothly. Generation of a ghost image that occurs due to a difference in electrical characteristics from the non-exposed portion can be suppressed.

  As described above, an electrophotographic photosensitive member that has excellent leakage resistance in an image forming apparatus including a contact charging unit, has electrical characteristics that are not affected by environmental fluctuations, and provides excellent development contrast. Can provide. Furthermore, the cost of the support can be reduced, and an electrophotographic photosensitive member capable of solving the problem of image defects caused by peeling or cracks in an image forming apparatus using a small-diameter drum or a belt-like support can be provided. As a result, the present invention has been completed.

  In the electrophotographic photoreceptor of the present invention, an undercoat layer containing at least two kinds of metal oxides having different average particle diameters and a thermosetting resin, and an intermediate containing an organometallic compound as a main component on a conductive support. An electrophotographic photosensitive member in which a layer and a photosensitive layer are sequentially laminated, and has good film formability and adhesion, is not affected by fluctuations in the external environment, and can maintain excellent electrophotographic characteristics over a long period of time. Can be provided at low cost. Furthermore, according to the present invention, since a superior effect can be obtained particularly in a small-diameter drum and a belt-shaped electrophotographic photosensitive member using a contact charging method, it is possible to provide a miniaturized image forming apparatus capable of realizing space saving. And

Hereinafter, the electrophotographic photoreceptor of the present invention will be described in detail with reference to the drawings.
For convenience of explanation, the multilayer photoconductor will be mainly described, but the present invention is not limited to the multilayer photoconductor.

FIG. 1 is a cross-sectional view showing an example of an electrophotographic photosensitive member used in the present invention, which contains two kinds of metal oxides having different average particle diameters and a thermosetting resin on a conductive support (21). An undercoat layer (22), an intermediate layer (23) containing an organometallic compound as a main component, and a photosensitive layer (26) containing at least a charge generation material and a charge transport material. .
FIG. 2 is a cross-sectional view showing another configuration, and an undercoat layer (22) containing two kinds of metal oxides having different average particle diameters and a thermosetting resin on a conductive support (21). And an intermediate layer (23) containing an organometallic compound as a main component, 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. It is what.

FIG. 3 is a cross-sectional view showing still another configuration, and an undercoat layer (22) containing two kinds of metal oxides having different average particle diameters and a thermosetting resin on a conductive support (21). And an intermediate layer (23) containing an organometallic compound as a main component, 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. Further, a protective layer (27) is formed thereon.
The constitution of the present invention comprises an undercoat layer containing at least two kinds of metal oxides having different average particle diameters and a thermosetting resin, an intermediate layer containing an organometallic compound as a main component, and a conductive support. As long as the photosensitive layers are sequentially formed, the above-described layers and the like may be arbitrarily combined.

This will be described in more detail below.
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 and an endless stainless steel belt that can be miniaturized because of the flexible layout 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 , Impact tube of aluminum disc, made into cup shape, II tube with outer surface finished by ironing, EI tube with outer surface of aluminum extruded tube finished by ironing, ED that has been cold drawn after extrusion The tube is known. As described in claim 8, the surface roughness is such that the ten-point average roughness (Rz) is 0.05 to 1.0 μm and the maximum height (Ry) is 0.5 to 1.5 μm. Preferably there is. These non-cutting aluminum tubes are prone to abnormal images such as moire, but according to the configuration of the present invention, even if non-cutting aluminum tubes are used, as will be apparent from the examples described later. It is possible to obtain an excellent electrophotographic photosensitive member that does not generate an abnormal image such as moiré and can maintain high image quality over a long period of time at low cost.

  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.

Furthermore, 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 fluororesin on a suitable cylindrical substrate. Those provided with a conductive layer can be favorably used as the conductive support (21) of the present invention.
The undercoat layer (22) contains the metal oxide and thermosetting resin shown in the present invention. Examples of the thermosetting resin include polyurethane, melamine resin, phenol resin, alkyd-melamine resin, epoxy resin, and other curable resins that form a three-dimensional network structure. From the surface, an alkyd-melamine resin or a phenol resin is preferably used. These binder resins may be used alone or in combination of two or more.
The undercoat layer (22) needs to have an appropriate resistance value by containing a metal oxide. A metal oxide having a specific resistance in the range of 10 ² to 10 ¹¹ Ω · cm can be suitably used. The undercoat layer (22) of the present invention contains two kinds of metal oxides having different average particle diameters, which can be exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like. The metal oxide used in the present invention may be affected by impurities such as hygroscopic substances such as Na ₂ O and K ₂ O and ionic substances contained in these metal oxides, which may affect electrophotographic characteristics. The purity of the product is desirably 95% or more.

Further, among these metal oxides, titanium oxide has an appropriate conductivity and is an N-type semiconducting particle having an electron as a conductive carrier, so that the injection of holes from the support is efficient. Block. In addition, the refractive index is higher than that of other metal oxides, and the light transmittance when the undercoat layer is made lower, so that it is particularly preferable because it has little influence on the image from the support.
In addition, these metal oxides can be used as appropriate in order to improve various properties such as improvement in dispersibility, etc., which have been subjected to surface coating treatment such as hydrous alumina treatment, hydrous silicon dioxide treatment, etc. In order to perform the surface treatment, it is also effective to subject the surface of the metal oxide particles to a plurality of times.

In order to obtain an appropriate specific resistance, it is also effective to provide a conductive coating layer using tin oxide or the like as necessary.
The weight ratio between the metal oxide and the binder resin is preferably 3/1 to 8/1. If it is 3/1 or less, 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 it is 8/1 or more, voids in the undercoat layer increase, and bubbles are generated when an intermediate layer is formed on the undercoat layer.

  When forming the undercoat layer (22), the undercoat layer coating solution in which the metal oxide and binder resin of the present invention and other additives as necessary are 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 dispersing the metal oxide in the undercoat layer coating liquid include a method using a ball mill, a roll mill, a sand mill, an ultrasonic disperser, and the like. Moreover, a dip coating method, a spray coating method, a ring coating method, a roll coater method and the like can be mentioned.
The coating of the undercoat layer (22) may be thermally cured immediately after the application of the undercoat layer, or may be performed by overheating when forming the intermediate layer (23) 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 (22) is preferably 1 μm or more, and more preferably about 3 to 10 μm as described in claim 7.

（式中、ＸはＺｒ、Ｔｉを表し、Ｒはアルキル基を表し、Ｒ’は、有機基を表し、ｍおよびｎは、それぞれ０以上であり、ｍ＋ｎ＝４である。）
一般式（１）中のＲ’で表される有機機としては、アセチルアセトン、２，４−ヘプタンジオンなどのβ−ジケトン類、アセト酢酸メチル、アセト酢酸エチル、アセト酢酸プロピル、アセト酢酸ブチルなどのケトエステル類、乳酸、酢酸、サリチル酸、リンゴ酸などのヒドロキシカルボン酸類、乳酸メチル、乳酸エチル、サリチル酸エチル、リンゴ酸エチルなどのヒドロキシカルボン酸エステル類、ジエチレングリコール、オクタンジオール、ヘキサンジオールなどのグリコール類、４−ヒドロキシ−４−メチル−２−ペンタノンなどのケトアルコール類から水素や水酸基が一部抜け、ジルコニウムと結合したものが好ましい特性を与える。 The intermediate layer (23) contains an organometallic compound represented by the following general formula (1) as a main component.

(In the formula, X represents Zr, Ti, R represents an alkyl group, R ′ represents an organic group, m and n are each 0 or more, and m + n = 4.)
Examples of the organic machine represented by R ′ in the general formula (1) include β-diketones such as acetylacetone and 2,4-heptanedione, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, and butyl acetoacetate. Ketoesters, hydroxycarboxylic acids such as lactic acid, acetic acid, salicylic acid and malic acid, hydroxycarboxylic acid esters such as methyl lactate, ethyl lactate, ethyl salicylate and ethyl malate, glycols such as diethylene glycol, octanediol and hexanediol, 4 Hydrogen and hydroxyl groups are partly lost from keto alcohols such as -hydroxy-4-methyl-2-pentanone and bonded with zirconium to give preferable characteristics.

As the organometallic compound used in the present invention, the following known materials can be used.
Examples of zirconium compounds include zirconium tri-n-butoxide pentanedionate, zirconium di-n-butoxide (bis-2,4-pentanedionate), zirconium triisopropoxide pentanedionate, zirconium diisopropoxide. (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, but are not limited to, toxide, zirconium lactate, methacrylate zirconium butoxide, stearylate zirconium butoxide, isostearate zirconium butoxide, and these are 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. (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- Butokiside, Titaniu Lactate, 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 the present invention, in addition to the metal organic compound, a silane coupling agent may be mixed and used for forming the intermediate layer.

  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.

In the present invention, 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. The mixing ratio is preferably set so that the resistivity is 10 ¹⁰ to 10 ¹³ Ω · cm. The bulk resistance of the intermediate layer (23) 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.

The intermediate layer (23) is composed of an organometallic compound as a main component, for example, by applying an intermediate layer coating solution containing a zirconium compound and a silane coupling agent on the undercoat layer, whereby the zirconium compound and the silane coupling are coated. It reacts with the agent to form an inorganic cured film that is stable in terms of electrical characteristics and is not affected by environmental fluctuations.
In forming the intermediate layer (23), an intermediate layer coating solution obtained by mixing the organometallic compound of the present invention in an appropriate solvent is used. A silane coupling agent can also be used as needed. 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 may be used alone or in combination 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. The drying temperature is 10 ° C to 250 ° C, preferably 100 ° C to 200 ° C. It can be carried out by air drying or static drying for 5 minutes to 6 hours, preferably 10 minutes to 2 hours in the range of ° C. 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 (25)).
The film thickness of the intermediate layer (23) 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 0.05 to 0.05 as described in claim 6. About 0.5 μm is appropriate.

In the present invention, the intermediate layer (23) containing an organometallic compound as a main component can be formed without generating cracks or pores in the film. It is considered that the undercoat layer (23) composed of the thermosetting resin has a function as a buffer layer that relieves local concentration of stress. Therefore, the intermediate layer (23) of the present invention can solve the problems such as gelation of the coating solution, lower sensitivity, and increase in residual potential in repeated use, which the conventional intermediate layer containing an organic resin component has. Is.
Further, when the undercoat layer (22) formed under the intermediate layer (23) has an effect of concealing defects on the surface of the support and is used in an image forming apparatus having contact charging means, In order to prevent the occurrence of pinholes, it is no longer necessary to increase the film thickness, and there is no problem in electrophotographic characteristics even with a thin film.

Next, the photosensitive layer (26) will be described. Although the photosensitive layer (26) in the present invention may be a laminated structure or a single layer structure, 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 a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, dibenzo An azo pigment having a thiophene skeleton, an azo pigment having a fluorenone skeleton, an azo pigment having an oxadiazol skeleton, an azo pigment having a bisstilbene skeleton, an azo pigment having a distyryl oxadiazol skeleton, and a distyrylcarbazole skeleton Azo pigments, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine dyes, Goido pigments, bisbenzimidazo - such as Le based pigments. These charge generation materials can be used alone or as a mixture of two or more.

The binder resin used for the charge generation layer (24) 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. . 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 weight, preferably 10 to 300 parts by weight with respect to 100 parts by weight 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, etc., exemplified in JP-A-63-285552, etc. 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- No. 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 JP-A-9-157378, JP-A-9-302084, JP-A-9-302805, JP-A-9-2 8226, 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) can 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 transport material include chloranil, 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 a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, or butanone together with the above-described inorganic or organic charge generation material together with a binder resin if necessary. 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 small 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 20 to 300 parts by weight, preferably 40 to 150 parts by weight, per 100 parts by weight of the binder resin.
In addition, a polymer charge transport material having a function as a binder resin and a function as a charge transport material is also preferably used for the charge transport layer (25). 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 can 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. Among these, the polymer charge transport materials of the following general formulas (1) to (10) are particularly effectively used, and these are exemplified below and specific examples are shown.

［式中、Ｒ_１、Ｒ_２、Ｒ_３はそれぞれ独立して置換もしくは無置換のアルキル基又はハロゲン原子、Ｒ_４は水素原子又は置換もしくは無置換のアルキル基、Ｒ_５、Ｒ_６は置換もしくは無置換のアリール基、ｏ、ｐ、ｑはそれぞれ独立して０〜４の整数、ｋ、ｊは組成を表し、０．１≦ｋ≦１、０≦ｊ≦０．９、ｎは繰り返し単位数を表し５〜５０００の整数である。Ｘは脂肪族の２価基、環状脂肪族の２価基、または下記一般式で表される２価基を表す。なお、一般式（１）は２つの共重合種が交互共重合の形で記載されているが、ランダム共重合体でも構わない。 [General formula (1)]

[Wherein R ₁ , R ₂ and R ₃ are each independently a substituted or unsubstituted alkyl group or a halogen atom, R ₄ is a hydrogen atom or a substituted or unsubstituted alkyl group, and R ₅ and R ₆ are substituted or Unsubstituted aryl group, o, p and q are each independently an integer of 0 to 4, k and j represent a composition, 0.1 ≦ k ≦ 1, 0 ≦ j ≦ 0.9, and n is a repeating unit It represents a number and is an integer from 5 to 5000. X represents an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following general formula. In the general formula (1), two copolymer species are described in the form of alternating copolymerization, but a random copolymer may be used.

｛式中、Ｒ_１０１、Ｒ_１０２は各々独立して置換もしくは無置換のアルキル基、アリール基またはハロゲン原子を表す。ｌ、ｍは０〜４の整数、Ｙは単結合、炭素原子数１〜１２の直鎖状、分岐状もしくは環状のアルキレン基、−Ｏ−、−Ｓ−、−ＳＯ−、−ＳＯ_２−、−ＣＯ−、−ＣＯ−Ｏ−Ｚ−Ｏ−ＣＯ−（式中Ｚは脂肪族の２価基を表す。）または、

（式中、ａは１〜２０の整数、ｂは１〜２０００の整数、Ｒ_１０３、Ｒ_１０４は置換または無置換のアルキル基又はアリール基を表す。）を表す。ここで、Ｒ_１０１とＲ_１０２、Ｒ_１０３とＲ_１０４は、それぞれ同一でも異なってもよい。｝］

{Wherein R ₁₀₁ and R ₁₀₂ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom. l and m are integers of 0 to 4, Y is a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —. , -CO-, -CO-O-Z-O-CO- (wherein Z represents an aliphatic divalent group) or

(Wherein, a represents an integer of 1 to 20, b represents an integer of 1 to 2000, and R ₁₀₃ and R ₁₀₄ represent a substituted or unsubstituted alkyl group or aryl group). Here, R ₁₀₁ and R ₁₀₂ , and R ₁₀₃ and R ₁₀₄ may be the same or different. }]

（式中、Ｒ_７、Ｒ_８は置換もしくは無置換のアリール基、Ａｒ_１、Ａｒ_２、Ａｒ_３は同一または異なるアリレン基を表す。Ｘ、ｋ、ｊおよびｎは、前記一般式（１）の場合と同じである。）なお、一般式（２）は２つの共重合種が交互共重合の形で記載されているが、ランダム共重合体でも構わない。 [General formula (2)]

(Wherein R ₇ and R ₈ represent a substituted or unsubstituted aryl group, Ar ₁ , Ar ₂ and Ar ₃ represent the same or different arylene groups. X, k, j and n represent the above general formula (1) In the general formula (2), two copolymer species are described in the form of alternating copolymerization, but a random copolymer may also be used.

（式中、Ｒ_９、Ｒ_１０は置換もしくは無置換のアリール基、Ａｒ_４、Ａｒ_５、Ａｒ_６は同一又は異なるアリレン基を表す。Ｘ、ｋ、ｊおよびｎは、前記一般式（１）の場合と同じである。）なお、一般式（３）は２つの共重合種が交互共重合の形で記載されているが、ランダム共重合体でも構わない。 [General formula (3)]

(Wherein R ₉ and R ₁₀ are substituted or unsubstituted aryl groups, Ar ₄ , Ar ₅ and Ar ₆ are the same or different arylene groups. X, k, j and n represent the above general formula (1) In the general formula (3), two copolymer species are described in the form of alternating copolymerization, but a random copolymer may also be used.

（式中、Ｒ_１１、Ｒ_１２は置換もしくは無置換のアリール基、Ａｒ_７、Ａｒ_８、Ａｒ_９は同一又は異なるアリレン基、ｐは１〜５の整数を表す。Ｘ、ｋ、ｊおよびｎは、前記一般式（１）の場合と同じである。）なお、一般式（４）は２つの共重合種が交互共重合の形で記載されているが、ランダム共重合体でも構わない。 [General formula (4)]

(Wherein R ₁₁ and R ₁₂ are substituted or unsubstituted aryl groups, Ar ₇ , Ar ₈ and Ar ₉ are the same or different arylene groups, and p represents an integer of 1 to 5. X, k, j and n Is the same as in the case of the general formula (1).) In the general formula (4), two copolymer species are described in the form of alternating copolymerization, but a random copolymer may be used.

（式中、Ｒ_１３、Ｒ_１４は置換もしくは無置換のアリール基、Ａｒ_１０、Ａｒ_１１、Ａｒ_１２は同一又は異なるアリレン基、Ｘ_１、Ｘ_２は置換もしくは無置換のエチレン基、又は置換もしくは無置換のビニレン基を表す。Ｘ、ｋ、ｊおよびｎは、前記一般式（１）の場合と同じである。）なお、一般式（５）は２つの共重合種が交互共重合の形で記載されているが、ランダム共重合体でも構わない。 [General formula (5)]

(Wherein R ₁₃ and R ₁₄ are substituted or unsubstituted aryl groups, Ar ₁₀ , Ar ₁₁ and Ar ₁₂ are the same or different arylene groups, X ₁ and X ₂ are substituted or unsubstituted ethylene groups, or substituted or unsubstituted Represents an unsubstituted vinylene group, wherein X, k, j and n are the same as in the general formula (1).) In the general formula (5), two copolymer species are in the form of alternating copolymerization. However, it may be a random copolymer.

（式中、Ｒ_１５、Ｒ_１６、Ｒ_１７、Ｒ_１８は置換もしくは無置換のアリール基、Ａｒ_１３、Ａｒ_１４、Ａｒ_１５、Ａｒ_１６は同一又は異なるアリレン基、Ｙ_１、Ｙ_２、Ｙ_３は単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表し同一であっても異なってもよい。Ｘ、ｋ、ｊおよびｎは、前記一般式（１）の場合と同じである。）なお、一般式（６）は２つの共重合種が交互共重合の形で記載されているが、ランダム共重合体でも構わない。 [General formula (6)]

(In the formula, R ₁₅ , R ₁₆ , R ₁₇ , R ₁₈ are substituted or unsubstituted aryl groups, Ar ₁₃ , Ar ₁₄ , Ar ₁₅ , Ar ₁₆ are the same or different arylene groups, Y ₁ , Y ₂ , Y _3. Represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group, which may be the same or different. X, k, j and n are the same as in the case of the general formula (1).) In the general formula (6), two copolymer species are described in the form of alternating copolymerization. A copolymer may be used.

（式中、Ｒ_１９、Ｒ_２０は水素原子、置換もしくは無置換のアリール基を表し、Ｒ_１９とＲ_２０は環を形成していてもよい。Ａｒ_１７、Ａｒ_１８、Ａｒ_１９は同一又は異なるアリレン基を表す。Ｘ、ｋ、ｊおよびｎは、前記一般式（１）の場合と同じである。）なお、一般式（７）は２つの共重合種が交互共重合の形で記載されているが、ランダム共重合体でも構わない。 [General formula (7)]

(In the formula, R ₁₉ and R ₂₀ represent a hydrogen atom, a substituted or unsubstituted aryl group, and R ₁₉ and R ₂₀ may form a ring. Ar ₁₇ , Ar ₁₈ , and Ar ₁₉ are the same or different. Represents an arylene group, and X, k, j and n are the same as those in the general formula (1).) In the general formula (7), two copolymer species are described in the form of alternating copolymerization. However, a random copolymer may be used.

（式中、Ｒ_２１は置換もしくは無置換のアリール基、Ａｒ_２０、Ａｒ_２１、Ａｒ_２２、Ａｒ_２３は同一又は異なるアリレン基を表す。Ｘ、ｋ、ｊおよびｎは、前記一般式（１）の場合と同じである。）なお、一般式（８）は２つの共重合種が交互共重合の形で記載されているが、ランダム共重合体でも構わない。 [General formula (8)]

(Wherein R ₂₁ represents a substituted or unsubstituted aryl group, Ar ₂₀ , Ar ₂₁ , Ar ₂₂ , and Ar ₂₃ represent the same or different arylene groups. X, k, j, and n represent the above general formula (1). In the general formula (8), two copolymer species are described in the form of alternating copolymerization, but a random copolymer may also be used.

（式中、Ｒ_２２、Ｒ_２３、Ｒ_２４、Ｒ_２５は置換もしくは無置換のアリール基、Ａｒ_２４、Ａｒ_２５、Ａｒ_２６、Ａｒ_２７、Ａｒ_２８は同一又は異なるアリレン基を表す。Ｘ、ｋ、ｊおよびｎは、前記一般式（１）の場合と同じである。）なお、一般式（９）は２つの共重合種が交互共重合の形で記載されているが、ランダム共重合体でも構わない。 [General formula (9)]

(In the formula, R ₂₂ , R ₂₃ , R ₂₄ , and R ₂₅ represent a substituted or unsubstituted aryl group, Ar ₂₄ , Ar ₂₅ , Ar ₂₆ , Ar ₂₇ , and Ar ₂₈ represent the same or different arylene groups. X, k , J and n are the same as those in the general formula (1).) In the general formula (9), two copolymer species are described in the form of alternating copolymerization. It doesn't matter.

（式中、Ｒ_２６、Ｒ_２７は置換もしくは無置換のアリール基、Ａｒ_２９、Ａｒ_３０、Ａｒ_３１は同一又は異なるアリレン基を表す。Ｘ、ｋ、ｊおよびｎは、前記一般式（１）の場合と同じである。）なお、一般式（１０）は２つの共重合種が交互共重合の形で記載されているが、ランダム共重合体でも構わない。 [General formula (10)]

(In the formula, R ₂₆ and R ₂₇ represent a substituted or unsubstituted aryl group, Ar ₂₉ , Ar ₃₀ and Ar ₃₁ represent the same or different arylene groups. X, k, j and n represent the above general formula (1). In the general formula (10), two copolymer species are described in the form of alternating copolymerization, but a random copolymer may also be 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, 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 inorganic and / or 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, but poor 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 and / 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 be used, and the above-described inorganic and / or organic particles can be used alone or in combination of two or more.
Further, these particles are preferably surface-treated with at least one inorganic substance or organic substance for reasons such as improving dispersibility and modifying the surface property.

Lowering the dispersibility of the particles not only increases the residual potential, but also lowers the transparency of the coating, causes defects in the coating, and lowers the abrasion resistance, preventing high durability or high image quality. 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, titanate coupling agents, aluminum coupling agents, zircoaluminate coupling agents, higher fatty acids, etc., or mixed treatments of these with silane coupling agents, 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 and / or organic particles is preferably 0 to 40% by weight, more preferably 0.1 to 30% by weight, based on the total solid content. If 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 particles is preferably pulverized and dispersed to 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 perform. If the particle size is larger than 1.0 μm, the particles may cue up on the surface of the photoreceptor, and the cleaning blade may be damaged, resulting in 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 obtained by dissolving or dispersing the above-described charge generating substance, charge transporting substance, binder resin, etc. in an appropriate solvent, and applying and drying this on the intermediate layer (23). Can be formed. 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 the like. It can be formed by coating with a 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.

In the electrophotographic 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)). is there.
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, inorganic and / or organic particles described in the description of the charge transport layer (25) may be added to the protective layer (27) for the purpose of improving wear resistance. 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 transport 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, oils and fats, and commercially available products can be easily obtained.

The addition amount of the antioxidant in this invention is 0 to 10 weight% with respect to the total weight of the layer to add.
The present invention provides the above-described electrophotographic photosensitive member, and also uses the electrophotographic photosensitive member of the present invention, a charging unit, an image exposing unit, a developing unit, and a transfer unit, and an image forming method of the present invention. 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.

Hereinafter, an image forming method and an image forming apparatus of the present invention will be described with reference to the drawings.
FIG. 4 is a schematic view showing an image forming method and an image forming apparatus of the present invention.
The electrophotographic photoreceptor of the present invention is used for the photoreceptor (11).
In FIG. 4, the photoconductor (11) has a drum shape, but may have a sheet shape or an endless belt shape as shown in FIG.
As the charging means (12), known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used. As the charging means (12), one that is in contact with or close to the photoreceptor is preferably used from the viewpoint of reducing 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 as described above is used. For the transfer means of the present invention, the above charger can be generally used, but a combination of a transfer charger and a separation charger is effective.

  The light source used for the exposure means (13), the charge removal means (1A), etc. includes fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LDs), electroluminescence ( EL) in general. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

  The toner (15) developed on the photoreceptor by the developing means (14) is transferred to the image receiving medium (18), but not all is transferred, and toner remaining on the photoreceptor is also generated. Such toner is removed from the photoreceptor by the cleaning means (17). As the cleaning means, a rubber cleaning blade, a brush such as a fur brush, a mag fur brush, or the like can be used. 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.

When a positive (negative) charge is applied to the electrophotographic photosensitive member and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with toner of negative (positive) polarity (detection fine particles), a positive image can be obtained, and if developed with toner of positive (negative) polarity, a negative image can be obtained. A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.
FIG. 5 is a schematic view showing another image forming method and an image forming apparatus of the present invention. The electrophotographic photoreceptor of the present invention is used for the photoreceptor (11). The photosensitive member (11) is driven by the driving means (1C), charged by the charging means (12), image exposure by the exposure means (13), development (not shown), transfer by the transfer means (16), and before cleaning. Exposure before cleaning by the exposure means (1B), cleaning by the cleaning means (17), 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. 5, 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, in the light irradiation process, image exposure, pre-cleaning exposure, and static elimination exposure are illustrated. In addition, pre-exposure exposure, pre-exposure of image exposure, and other known light irradiation processes are provided to light the photosensitive member. Irradiation can also be performed.

The present invention further includes the electrophotographic photosensitive member and at least one means selected from a charging unit, an image exposure unit, a developing unit, a transfer unit, a fixing unit, a transfer unit, and a cleaning unit. The present invention provides an image forming apparatus process cartridge and an image forming apparatus equipped with the image forming apparatus process cartridge, wherein the electrophotographic photosensitive member and the means are integrally detachable from the main body of the image forming apparatus. Is.
The image forming means described so far may be fixedly incorporated in a copying machine, a facsimile machine, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge and detachable. 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. ).

FIG. 6 is a schematic view showing an example of a process cartridge for an image forming apparatus according to the present invention. The electrophotographic photoreceptor of the present invention is used for the photoreceptor (11). There are many types of process cartridges and the like, but the one shown in FIG. 6 is an example of a general process cartridge using contact charging means.
The conductive support used in the present invention uses Surfcom 1400D (manufactured by Tokyo Seimitsu), and evaluates the surface roughness Rz (JIS B0601-1994 standard) as the evaluation length (Ln): 4 mm, the reference length (L): 0.8 mm and maximum height Ry (JIS B0601-1994 standard) were measured at an evaluation length (L) of 4 mm and a reference length (L) of 0.8 mm.

The ten-point average roughness (Rz) is a reference length (L) extracted from the roughness curve in the direction of the average line, and from the average line of this extracted part, the highest peak height from the highest peak to the fifth peak It is the sum of the average value of the absolute values of (Yp) and the average value of the absolute values of the altitude (Yv) from the lowest valley bottom to the fifth.
The maximum height (Ry) is extracted from the roughness curve by the reference length (L) in the direction of the average line, and the height (Yp) from the average line length of this extracted part to the highest peak. , The sum to the lowest depth (Yv) to the valley bottom.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to a following example.
In addition, all the parts used in an Example represent a weight part.
Example 1
[Photosensitive member production example 1]
An ED tube (ten-point average roughness (Rz): 0.55 μm, maximum height (Ry): 0.7 μm) made of 3003 series aluminum alloy with a diameter of 30 mm and a length of 340 mm is prepared as a conductive cylindrical support. did. On the ED tube, the coating solution for the undercoat layer, the coating solution for the intermediate layer, the coating solution for the charge generation layer, and the coating solution for the charge transport layer are sequentially applied and dried on the ED tube, thereby the present invention. Photoconductor 1 was obtained.

[Coating liquid for undercoat layer]
A mixture having the following composition was dispersed with a ball mill for 72 hours to prepare an undercoat layer coating solution. The undercoat layer coating solution was dip-coated on the ED tube, and then dried at 120 ° C. for 25 minutes to form an undercoat layer of about 3.0 μm.
40 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Titanium oxide T ₂ 60 parts (PT-401M average particle size: 0.07 μm, Ishihara Sangyo Co., Ltd. alkyd resin 20 parts (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.)
(Made by company)
Melamine resin 10 parts (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
100 parts of methyl ethyl ketone

[Coating liquid for intermediate layer]
An intermediate layer coating solution having the following constitution was applied onto the undercoat layer by a ring coating machine and heated at 140 ° C. for 10 minutes to form an about 0.15 μm intermediate layer.
Tributoxyzirconium acetylacetonate 10 parts (Orgachix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
Ethyl alcohol 75 parts n-Butyl alcohol 25 parts [Coating liquid for charge generation layer]
A coating solution for charge generation layer having the following composition was dip coated on the intermediate layer and then dried by heating at 120 ° C. for 20 minutes to form a 0.2 μm charge generation layer.
Oxotitanium phthalocyanine pigment 2 parts Polyvinyl butyral 0.2 part (S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.)
50 parts of tetrahydrofuran

ビスフェノールＺポリカーボネート １０部
（パンライトＴＳ−２０５０：帝人化成社製）
シリコーンオイル ０．００２部
（ＫＦ−５０、信越化学工業社製）
テトラヒドロフラン １００部 [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 heated and dried at 135 ° C. for 20 minutes to form a 20 μm charge transport layer.
10 parts of charge transport material (D-1) represented by the following structural formula

Bisphenol Z polycarbonate 10 parts (Panlite TS-2050: manufactured by Teijin Chemicals Ltd.)
0.002 part of silicone oil (KF-50, manufactured by Shin-Etsu Chemical Co., Ltd.)
Tetrahydrofuran 100 parts

(Example 2)
[Photoconductor Preparation Example 2]
Photoreceptor 2 was prepared in the same manner as Photoreceptor Preparation Example 1 except that the thickness of the undercoat layer in Photoreceptor Preparation Example 1 was changed to 6.0 μm.
(Example 3)
[Photoconductor Preparation Example 3]
Photoreceptor 3 was prepared in the same manner as Photoreceptor Preparation Example 2, except that the intermediate layer coating solution in Photoreceptor Preparation Example 2 was changed to one having the following composition.
[Coating liquid for intermediate layer]
Tributoxyzirconium acetylacetonate 10 parts (Orgachix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
γ-aminopropyltrimethoxysilane 0.24 parts (A1110, manufactured by Nippon Unicar Co., Ltd.)
Ethyl alcohol 75 parts n-Butyl alcohol 25 parts

Example 4
[Photoconductor Preparation Example 4]
Photoreceptor 4 was produced in the same manner as Photoreceptor Production Example 3, except that the undercoat layer coating solution in Photoreceptor Production Example 3 was changed to one having the following composition.
[Coating liquid for undercoat layer]
40 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
40 parts of titanium oxide T ₂ (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
16 parts alkyd resin (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
9 parts of melamine resin (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
80 parts of methyl ethyl ketone

(Example 5)
[Photoconductor Preparation Example 5]
Photoreceptor 5 was produced in the same manner as Photoreceptor Production Example 3, except that the undercoat layer coating solution in Photoreceptor Production Example 3 was changed to the one having the following composition.
[Coating liquid for undercoat layer]
20 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
80 parts of titanium oxide T ₂ (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Alkyd resin 20 parts (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
Melamine resin 10 parts (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
100 parts of methyl ethyl ketone

(Comparative Example 1)
[Photoconductor Preparation Example 6]
Photoreceptor 6 was prepared in the same manner as Photoreceptor Preparation Example 3 except that the undercoat layer coating solution in Photoreceptor Preparation Example 3 was changed to one having the following composition.
[Coating liquid for undercoat layer]
100 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Alkyd resin 20 parts (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
Melamine resin 10 parts (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
100 parts of methyl ethyl ketone

(Comparative Example 2)
[Photoconductor Preparation Example 7]
In Photoconductor Preparation Example 6, Photoconductor 7 was prepared in the same manner as Photoconductor Preparation Example 6 except that no intermediate layer was provided.
(Example 6)
[Photoconductor Preparation Example 8]
Photoreceptor 8 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.
[Coating liquid for undercoat layer]
Titanium oxide T ₁ 40 parts (TA-3000 average particle size: 0.30 μm, manufactured by Fuji Titanium Industry Co., Ltd.)
Titanium oxide T ₂ 60 parts (PT-401M average particle size: 0.07 μm, Ishihara Sangyo Co., Ltd. phenol resin 23 parts (Bryofen J-325, solid content: 70%, Dainippon Ink & Chemicals, Inc.)
(Made by company)
100 parts of 2-methoxy-1-propanol

(Example 7)
[Photoconductor Preparation Example 9]
Photoreceptor 9 was produced in the same manner as Photoreceptor Production Example 8, except that the thickness of the undercoat layer in Photoreceptor Production Example 8 was changed to 6.0 μm.
(Example 8)
[Photoconductor Preparation Example 10]
Photoreceptor 10 was produced in the same manner as Photoreceptor Production Example 9, except that the intermediate layer coating solution in Photoreceptor Production Example 9 was changed to one having the following composition.
[Coating liquid for intermediate layer]
16.5 parts of tributoxyzirconium acetylacetonate (Orgatrix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
N (3-Tributoxysilylpropyl) -1,6-hexylenediamine 5 parts (KBM-6063, manufactured by Shin-Etsu Chemical Co., Ltd.)
400 parts of isopropyl alcohol

(Comparative Example 3)
[Photoreceptor Preparation Example 11]
In Photoconductor Preparation Example 3, Photoconductor 11 was prepared in the same manner as Photoconductor Preparation Example 3 except that the undercoat layer coating solution was changed to the following composition and a 4.5 μm undercoat layer was provided.
[Coating liquid for undercoat layer]
40 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
60 parts of titanium oxide T ₂ (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
25 parts of polyamide resin (Amilan CM8000, manufactured by Toray Industries, Inc.)
Methyl alcohol 64 parts n-Butyl alcohol 16 parts

(Comparative Example 4)
[Photoconductor Preparation Example 12]
Photoreceptor 12 was produced in the same manner as Photoreceptor Production Example 3 except that no undercoat layer was provided in Photoreceptor Production Example 3.
(Comparative Example 5)
[Photoconductor Preparation Example 13]
Photoreceptor 13 was prepared in the same manner as Photoreceptor Preparation Example 2, except that the intermediate layer coating solution in Photoreceptor Preparation Example 2 was changed to the following composition, and the thickness of the intermediate layer was changed to 1.0 μm. .
[Coating liquid for intermediate layer]
8 parts of polyamide resin (CM8000, manufactured by Toray Industries, Inc.)
Methyl alcohol 60 parts n-butyl alcohol 32 parts (Comparative Example 6)
[Photoconductor Preparation Example 14]
Photoconductor 14 was prepared in the same manner as in Photoconductor Preparation Example 2 except that no intermediate layer was provided in Photoconductor Preparation Example 2.

(Comparative Example 7)
[Photoconductor Preparation Example 15]
Photoreceptor 15 was produced in the same manner as Photoreceptor Production Example 2 except that the intermediate layer coating solution in Photoreceptor Production Example 2 was changed to one having the following composition and an intermediate layer of 1.5 μm was provided.
[Coating liquid for intermediate layer]
20 parts of tributoxyzirconium acetylacetonate (Orgatechs ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
γ-aminopropyltrimethoxysilane 2 parts (A1110, manufactured by Nippon Unicar Co., Ltd.)
Polyvinyl butyral resin 1.5 parts (ESREC BM-S, manufactured by Sekisui Chemical Co., Ltd.)
70 parts of n-butyl alcohol

Example 9
[Photoconductor Preparation Example 16]
Photoreceptor 16 was prepared in the same manner as Photoreceptor Preparation Example 3, except that the charge transport layer coating solution in Photoreceptor Preparation Example 3 was changed to one having the following composition.
[Coating liquid for charge transport layer]
10 parts of the above charge transport material (D-1) 10 parts of bisphenol Z polycarbonate (Panlite TS-2050: manufactured by Teijin Chemicals Ltd.)
Polytetrafluoroethylene (PTFE) particles (Lubrun L-2, manufactured by Daikin Industries, Ltd.) 1 part Comb type fluorine-based graft polymer (GF300, manufactured by Toagosei Co., Ltd.) 0.1 part Tetrahydrofuran 70 parts

（ｋ＝０．４２、ｊ＝０．５８、Ｍｗ＝１６００００（ポリスチレン換算））
テトラヒドロフラン 1００部 (Example 10)
[Photoconductor Preparation Example 17]
Photoreceptor 17 was produced in the same manner as Photoreceptor Production Example 3, except that the charge transport layer coating solution in Photoreceptor Production Example 3 was changed to one having the following composition.
[Coating liquid for charge transport layer]
Polymer charge transport (PD-1) represented by the following structural formula 10 parts

(K = 0.42, j = 0.58, Mw = 16000 (polystyrene conversion))
100 parts of tetrahydrofuran

ポリビニルブチラール ２．０部
（エスレックＢＭ−１：積水化学工業（株）製）
シクロヘキサノン ２００部
メチルエチルケトン ８０部 (Example 11)
[Photoconductor Preparation Example 18]
The conductive cylindrical support in the photoreceptor preparation example 1 is an ED tube made of 3003 series aluminum alloy having a diameter of 24 mm and a length of 246 mm (10-point average roughness (Rz): 0.80 μm, maximum height (Ry): The photosensitive member 18 was prepared in the same manner as in the photosensitive member preparation example 1 except that the intermediate layer coating solution and the charge generation layer coating solution were changed to those having the following composition.
[Coating liquid for intermediate layer]
10 parts dipropyloxytitanium acetylacetonate (TC100, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
Isopropyl alcohol 70 parts [Coating liquid for charge generation layer]
Bisazo pigment represented by the following structural formula 2.5 parts

Polyvinyl butyral 2.0 parts (ESREC BM-1: manufactured by Sekisui Chemical Co., Ltd.)
Cyclohexanone 200 parts Methyl ethyl ketone 80 parts

(Example 12)
[Photoconductor Preparation Example 19]
Photoreceptor 19 was produced in the same manner as Photoreceptor Production Example 18, except that the thickness of the undercoat layer in Photoreceptor Production Example 18 was changed to 6.0 μm.
(Example 13)
[Photoconductor Preparation Example 20]
Photoconductor 20 was prepared in the same manner as Photoconductor preparation example 19 except that the intermediate layer coating solution in Photoconductor preparation example 19 was changed to one having the following composition.
[Coating liquid for intermediate layer]
10 parts dipropyloxytitanium acetylacetonate (Orgatechs TC100, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
1 part of γ-aminopropyltrimethoxysilane (A1110, manufactured by Nippon Unicar Co., Ltd.)
Isopropyl alcohol 40 parts n-Butyl alcohol 20 parts

(Comparative Example 8)
[Photoconductor Preparation Example 21]
A photoreceptor 21 was prepared in the same manner as in the photoreceptor preparation example 19 except that the undercoat layer coating solution in the photoreceptor preparation example 19 was changed to one having the following composition and no intermediate layer was provided.
[Coating liquid for undercoat layer]
40 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
40 parts of titanium oxide T ₂ (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
16 parts alkyd resin (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
9 parts of melamine resin (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
80 parts of methyl ethyl ketone

(Example 14)
[Photoconductor Preparation Example 22]
Photoconductor 22 was prepared in the same manner as Photoconductor preparation example 20, except that the undercoat layer coating solution in Photoconductor preparation example 20 was changed to one having the following composition.
[Coating liquid for undercoat layer]
85 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Titanium oxide T ₂ 15 parts (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Alkyd resin 20 parts (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
Melamine resin 10 parts (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
100 parts of methyl ethyl ketone

(Example 15)
[Photoconductor Preparation Example 23]
A photoconductor 23 was produced in the same manner as in the photoconductor production example 20, except that the undercoat layer coating solution in the photoconductor production example 20 was changed to one having the following composition.
[Coating liquid for undercoat layer]
30 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
50 parts of titanium oxide T ₂ (TTO-F1 average particle size: 0.04 μm, manufactured by Ishihara Sangyo Co., Ltd.)
16 parts alkyd resin (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
9 parts of melamine resin (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
100 parts of methyl ethyl ketone

(Comparative Example 9)
[Photoconductor Preparation Example 24]
Photoreceptor 24 was produced in the same manner as Photoreceptor Production Example 20, except that the undercoat layer coating solution in Photoreceptor Production Example 20 was changed to one having the following composition.
[Coating liquid for undercoat layer]
100 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Alkyd resin 20 parts (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
Melamine resin 10 parts (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
100 parts of methyl ethyl ketone

(Comparative Example 10)
[Photoconductor Preparation Example 25]
A photoconductor 25 was produced in the same manner as in the photoconductor production example 20, except that the undercoat layer coating solution in the photoconductor production example 20 was changed to one having the following composition.
[Coating liquid for undercoat layer]
100 parts of titanium oxide T ₂ (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Alkyd resin 20 parts (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
Melamine resin 10 parts (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
100 parts of methyl ethyl ketone

(Comparative Example 11)
[Photoconductor Preparation Example 26]
In Photoconductor Preparation Example 18, Photoconductor 26 was prepared in the same manner as Photoconductor Preparation Example 5 except that the undercoat layer coating solution was changed to one having the following composition and a 1.0 μm undercoat layer was provided.
[Coating liquid for undercoat layer]
Polyamide 8 parts (CM8000, manufactured by Toray Industries, Inc.)
Methyl alcohol 60 parts n-butyl alcohol 32 parts (Comparative Example 12)
[Photoconductor Preparation Example 27]
A photoconductor 27 was produced in the same manner as in the photoconductor production example 20, except that no undercoat layer was provided in the photoconductor production example 20.

(Comparative Example 13)
[Photoconductor Preparation Example 28]
A photoconductor 28 was prepared in the same manner as in Photoconductor Preparation Example 27 except that the intermediate layer coating solution in Photoconductor Preparation Example 27 was changed to the one having the following composition and a 1.5 μm intermediate layer was provided.
[Coating liquid for intermediate layer]
10 parts dipropyloxytitanium acetylacetonate (Orgatechs TC100, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
1 part of γ-aminopropyltrimethoxysilane (A1110, manufactured by Nippon Unicar Co., Ltd.)
Polyvinyl butyral resin 1.5 parts (ESREC BM-1, manufactured by Sekisui Chemical Co., Ltd.)
70 parts isopropyl alcohol

(Comparative Example 14)
[Photoconductor Preparation Example 29]
A photoconductor 29 was produced in the same manner as in the photoconductor production example 20, except that the intermediate layer coating solution in the photoconductor production example 20 was changed to one having the following composition.
[Coating liquid for intermediate layer]
10 parts dipropyloxytitanium acetylacetonate (Orgatechs TC100, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
1 part of γ-aminopropyltrimethoxysilane (A1110, manufactured by Nippon Unicar Co., Ltd.)
Polyvinyl butyral resin 1.5 parts (ESREC BM-1, manufactured by Sekisui Chemical Co., Ltd.)
70 parts isopropyl alcohol

（ｋ＝０．５０、ｊ＝０．５０、Ｍｗ＝１３５０００（ポリスチレン換算））
テトラヒドロフラン 1００部 (Example 16)
[Photoconductor Preparation Example 30]
Photoreceptor 30 was produced in the same manner as Photoreceptor Production Example 20, except that the charge transport layer coating solution in Photoreceptor Production Example 20 was changed to one having the following composition.
[Coating liquid for charge transport layer]
Polymer charge transport (PD-2) represented by the following structural formula 10 parts

(K = 0.50, j = 0.50, Mw = 135000 (polystyrene conversion))
100 parts of tetrahydrofuran

（ｋ＝０．５０、ｊ＝０．５０、Ｍｗ＝１５５０００（ポリスチレン換算））
テトラヒドロフラン 1００部 (Example 17)
[Photoconductor Preparation Example 31]
Photoreceptor 31 was prepared in the same manner as Photoreceptor Preparation Example 20 except that the charge transport layer coating solution in Photoreceptor Preparation Example 20 was changed to one having the following composition.
[Coating liquid for charge transport layer]
Polymer charge transport (PD-3) represented by the following structural formula 10 parts

(K = 0.50, j = 0.50, Mw = 155000 (polystyrene conversion))
100 parts of tetrahydrofuran

(Example 18)
[Photoconductor Preparation Example 32]
A photoconductor preparation example except that a protective layer coating solution having the following composition was spray-coated on the charge transport layer in Photoconductor Preparation Example 20 and then dried by heating at 110 ° C. for 20 minutes to provide a protective layer of 5 μm. In the same manner as in Example 20, a photoconductor 32 was produced.
[Coating liquid for protective layer]
7 parts of the above charge transport material (D-1) 10 parts of bisphenol Z polycarbonate (Panlite TS-2050: manufactured by Teijin Chemicals Ltd.)
6 parts of alumina fine particles (Sumicorundum AA-03, center particle size 0.3 μm, manufactured by Sumitomo Chemical Co., Ltd.)
Dispersing aid 0.08 parts (BYK-P104 manufactured by Big Chemie Japan)
Tetrahydrofuran 700 parts Cyclohexanone 200 parts

Example 19
[Photoconductor Preparation Example 33]
A 30 μm thick nickel seamless belt (10-point average roughness (Rz): 0.70 μm, maximum height (Ry): 1.1 μm) was prepared as a conductive support. On this nickel seamless belt, an undercoat layer coating solution and an intermediate layer coating solution having the following composition were sequentially applied and dried to obtain a photoreceptor 33 of the present invention.
[Coating liquid for undercoat layer]
A mixture having the following composition was dispersed with a ball mill for 72 hours to prepare an undercoat layer coating solution. The undercoat layer coating solution was spray-coated on the nickel seamless belt and then dried at 120 ° C. for 25 minutes to form an undercoat layer of about 3.0 μm.
40 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
60 parts of titanium oxide T ₂ (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Alkyd resin 20 parts (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
Melamine resin 10 parts (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
100 parts of methyl ethyl ketone [coating liquid for intermediate layer]
The intermediate layer coating solution having the following constitution was applied onto the undercoat layer by a spray coating machine and heated at 140 ° C. for 10 minutes to form an about 0.15 μm intermediate layer.
Tributoxyzirconium acetylacetonate 10 parts (Orgachix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
Ethyl alcohol 75 parts n-Butyl alcohol 25 parts

(Example 20)
[Photoconductor Preparation Example 34]
A photoconductor 34 was produced in the same manner as in the photoconductor production example 33 except that the thickness of the undercoat layer in the photoconductor production example 33 was changed to 6.0 μm.
(Example 21)
[Photoconductor Preparation Example 35]
A photoreceptor 35 was produced in the same manner as in the photoreceptor preparation example 34 except that the undercoat layer coating solution and the intermediate layer coating solution in the photoreceptor preparation example 34 were changed to those having the following compositions.
[Coating liquid for undercoat layer]
40 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
40 parts of titanium oxide T ₂ (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
16 parts alkyd resin (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
9 parts of melamine resin (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
80 parts of methyl ethyl ketone [coating liquid for intermediate layer]
Tributoxyzirconium acetylacetonate 10 parts (Orgachix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
γ-aminopropyltrimethoxysilane 0.24 parts (A1110, manufactured by Nippon Unicar Co., Ltd.)
Ethyl alcohol 75 parts n-Butyl alcohol 25 parts

(Example 22)
[Photoconductor Preparation Example 36]
A photoreceptor 36 was produced in the same manner as in the photoreceptor preparation example 35, except that the undercoat layer coating solution in the photoreceptor preparation example 35 was changed to one having the following composition.
[Coating liquid for undercoat layer]
85 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Titanium oxide T ₂ 15 parts (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Alkyd resin 20 parts (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
Melamine resin 10 parts (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
100 parts of methyl ethyl ketone

(Comparative Example 15)
[Photoconductor Preparation Example 37]
A photoreceptor 37 was prepared in the same manner as in the photoreceptor preparation example 34, except that the intermediate layer coating solution in the photoreceptor preparation example 34 was changed to the one having the following composition and a 1.5 μm intermediate layer was provided.
[Coating liquid for intermediate layer]
20 parts of tributoxyzirconium acetylacetonate (Orgatechs ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
γ-aminopropyltrimethoxysilane 2 parts (A1110, manufactured by Nippon Unicar Co., Ltd.)
Polyvinyl butyral resin 1.5 parts (ESREC BM-S, manufactured by Sekisui Chemical Co., Ltd.)
70 parts of n-butyl alcohol

(Example 23)
[Photoconductor Preparation Example 38]
A photoreceptor 38 was produced in the same manner as in the photoreceptor preparation example 35 except that the undercoat layer coating solution in the photoreceptor preparation example 35 was changed to one having the following composition.
[Coating liquid for undercoat layer]
40 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
60 parts of titanium oxide T ₂ (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Phenol resin 23 parts (Bryofen J-325, solid content: 70%, Dainippon Ink and Chemicals, Inc.
(Made by company)
100 parts of 2-methoxy-1-propanol

(Example 24)
[Photoconductor Preparation Example 39]
A photoconductor 39 was prepared in the same manner as in the photoconductor preparation example 35 except that the undercoat layer coating solution in the photoconductor preparation example 35 was changed to one having the following composition.
[Coating liquid for undercoat layer]
30 parts of titanium oxide T ₁ (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
50 parts of titanium oxide T ₂ (TTO-F1 average particle size: 0.04 μm, manufactured by Ishihara Sangyo Co., Ltd.)
16 parts alkyd resin (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
9 parts of melamine resin (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
100 parts of methyl ethyl ketone

(Comparative Example 16)
[Photoconductor Preparation Example 40]
The photoreceptor 40 was produced in the same manner as in the photoreceptor preparation example 35 except that the undercoat layer coating solution in the photoreceptor preparation example 35 was changed to the one having the following composition and a 3.0 μm undercoat layer was provided.
[Coating liquid for undercoat layer]
100 parts of titanium oxide T ₁ (TA-3000 average particle size: 0.30 μm, manufactured by Fuji Titanium Industry Co., Ltd.)
Alkyd resin 20 parts (Beckolite M6401-50, solid content: 50%, Dainippon Ink & Chemicals, Inc.
(Made by company)
Melamine resin 10 parts (Super Becamine G-821-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.)
100 parts of methyl ethyl ketone

(Comparative Example 17)
[Photoconductor Preparation Example 41]
A photoconductor 41 was produced in the same manner as in the photoconductor production example 40 except that the thickness of the undercoat layer in the photoconductor production example 40 was changed to 6.0 μm.
(Comparative Example 18)
[Photoconductor Preparation Example 42]
The photoreceptor 42 was produced in the same manner as in the photoreceptor preparation example 35 except that the undercoat layer coating solution in the photoreceptor preparation example 35 was changed to one having the following composition and a 3.0 μm undercoat layer was provided.
[Coating liquid for undercoat layer]
100 parts of titanium oxide T ₁ (CR-EL average particle size: 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Phenol resin 23 parts (Bryofen J-325, solid content: 70%, Dainippon Ink and Chemicals, Inc.
(Made by company)
100 parts of 2-methoxy-1-propanol

(Comparative Example 19)
[Photoconductor Preparation Example 43]
A photoconductor 43 was prepared in the same manner as in the photoconductor preparation example 42 except that the thickness of the undercoat layer in the photoconductor preparation example 42 was changed to 6.0 μm.
(Comparative Example 20)
[Photoconductor Preparation Example 44]
A photoreceptor 44 was prepared in the same manner as in the photoreceptor preparation example 35 except that the undercoat layer coating solution in the photoreceptor preparation example 35 was changed to the one having the following composition [undercoat layer coating solution].
100 parts of titanium oxide T ₂ (PT-401M average particle size: 0.07 μm, manufactured by Ishihara Sangyo Co., Ltd.)
Phenol resin 23 parts (Bryofen J-325, solid content: 70%, Dainippon Ink and Chemicals, Inc.
(Made by company)
100 parts of 2-methoxy-1-propanol

The photoreceptors produced as described above are shown in Table 1.

Regarding the electrophotographic photoreceptors 1 to 32 produced as described above, it was confirmed that cracks or pores were generated on the surface of the electrophotographic photoreceptor after forming the intermediate layer. Thereafter, the electrophotographic photosensitive member in which the charge generation layer, the charge transport layer or the charge generation layer, the charge transport layer and the protective layer were sequentially formed on the intermediate layer was mounted on the electrophotographic process cartridge shown in FIG.
The electrophotographic photosensitive members 1 to 17 are mounted on the electrophotographic process cartridge shown in FIG. 6 and then provided with a 780 nm semiconductor laser (writing with a polygon mirror) as an image exposure means and a contact charging roller as a charging means. The image forming apparatus (Imagio MF-2200 manufactured by Ricoh Co., Ltd.) was mounted, and the initial dark part potential (VD) and exposure part potential (VL) were measured. As for the exposure portion potential, an electrometer probe was attached to the developing portion of the apparatus shown in FIG. 6, and the surface potential of the photosensitive member when moving to the developing portion after charging and image exposure was measured. Initial setting was performed so that the charging potential (dark portion potential: VD) was −600 V and VL was −100 (V). ΔVD and ΔVL represent the amount of change in potential of the dark portion potential and the exposure portion potential after the initial time and after the 50,000-sheet passing test, respectively. Subsequently, 50,000 sheets of A4 size PPC paper are fed in the vertical direction in an environment of normal temperature and normal humidity (23 ° C 55% RH), low temperature and low humidity (15 ° C 25% RH), and high temperature and high humidity (30 ° C 80% RH). The paper was passed through and VD and VL measurements and image evaluation were performed.

Similarly, after the electrophotographic photosensitive members 18 to 32 are mounted on the electrophotographic process cartridge shown in FIG. 6, the process cartridge is converted into an image exposure light source: 655 nm semiconductor laser (writing by a polygon mirror). (Ricoh: FAX 1160L), A4 size PPC paper is placed in an environment of normal temperature and humidity (23 ° C 55% RH), low temperature and low humidity (15 ° C 25% RH), and high temperature and high humidity (30 ° C 80% RH). 50,000 sheets were passed in the vertical feed, and VD and VL measurements and image evaluation were performed.
ΔVD and ΔVL represent the potential change amount of the dark portion potential and the exposure portion potential after the initial time and after the 50,000 sheet passing test, respectively.
ΔVD = (Dark part potential at initial time: −600 V) − (Dark part potential after passing 50,000 sheets)
ΔVL = (exposure portion potential at initial time: −100 V) − (exposure portion potential after passing 50,000 sheets)

The evaluation results are shown in Tables 2 and 3.
Visually evaluate the occurrence of cracks or pores on the surface of the intermediate layer,
A: Not observed at all O: Slightly observed Δ: Slightly observed ×: Cracks at a level that deteriorates the image quality were generated.
Evaluation of moire image, pinhole leak, dirt
○: Not observed at all Δ: Slightly observed, but no problem in actual use ×: Level at which image quality is degraded.
Evaluation of ghost: ○: Not seen at all ×: Image quality may be deteriorated.

Subsequently, the electrophotographic photoreceptors 33 to 43 produced as described above are mounted on an image forming apparatus (IPSiO Color 5000), and the apparatus is continuously operated for 72 hours to remove the undercoat layer and the intermediate layer, cracks, etc. Evaluation was performed.
The evaluation results are shown in Table 4.

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 electrophotographic apparatus according to the present invention. It is the schematic which shows another example of the electrophotographic apparatus which concerns on this invention. 1 shows an example of a process cartridge according to the present invention. It is a schematic diagram which shows the ten-point average roughness (Rz) regarding the surface state of the electroconductive support body which concerns on this invention. It is a schematic diagram which shows the maximum height (Ry) regarding the surface state of the electroconductive support body which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Electrophotographic photoreceptor 12 Charging means 13 Exposure means 14 Developing means 15 Toner 16 Transfer means 17 Cleaning means 18 Image receiving medium 19 Fixing means 21 Conductive support 22 Charge generation layer 23 Charge transport layer 24 Photosensitive layer 25 Undercoat layer 26 Protection Layer 1A Neutralizing means 1B Exposure means before cleaning 1C Driving means

Claims (18)

  In an electrophotographic photosensitive member in which at least an undercoat layer, an intermediate layer, and a photosensitive layer are sequentially laminated on a conductive support, the undercoat layer has at least two metal oxides having different average particle diameters and thermosetting properties. An electrophotographic photoreceptor comprising a resin and the intermediate layer containing an organometallic compound as a main component. When the metal oxide is titanium oxide, and the average particle size of _one titanium oxide (T ₁ ) is (D ₁ ) and the other titanium oxide (T ₂ ) is (D ₂ ), The electrophotographic photosensitive member according to claim 1, wherein a relationship of 0.2 <D ₂ / D ₁ ≦ 0.5 is satisfied. The average particle diameter _{(D 2)} is 0.05μm _<D 2 _<0.20μm, and the mixing weight ratio of _{(T 1)} and _{(T 2)} of titanium oxide _{(T 2)} is, 0.2 ≦ The electrophotographic photosensitive member according to claim _{1, wherein} T ₂ / (T ₁ + T ₂ ) ≦ 0.8. 4. The electrophotographic photoreceptor according to claim 1, wherein the intermediate layer contains a polymer produced from an organometallic compound represented by the following general formula (1).

(In the formula, X represents Zr, Ti, R represents an alkyl group, R ′ represents an organic group, m and n are each 0 or more, and m + n = 4.)   The electrophotographic photosensitive member according to claim 1, wherein the intermediate layer contains an organometallic compound and a silane coupling agent.   6. The electrophotographic photosensitive member according to claim 1, wherein the intermediate layer has a thickness of 0.05 to 0.5 [mu] m.   The electrophotographic photosensitive member according to claim 1, wherein the undercoat layer has a thickness of 3 to 15 μm.   2. The surface roughness of the conductive support is 0.05 to 1.0 [mu] m at a 10-point average roughness Rz and 0.5 to 1.5 [mu] m at a maximum height Ry. The electrophotographic photosensitive member according to any one of 1 to 7.   9. The electrophotographic photosensitive member according to claim 1, wherein the conductive support is a non-cutting tube made of aluminum or an aluminum alloy.   The electrophotographic photosensitive member according to claim 1, wherein the conductive support is a conductive cylindrical support having a diameter of 30 mm or less.   9. The electrophotographic photosensitive member according to claim 1, wherein the conductive support is an endless belt.   12. An image forming method comprising using at least 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 method according to claim 12, wherein the charging unit is a charging unit that performs charging by a charging member arranged in contact with the charging unit.   An image forming apparatus comprising at least the electrophotographic photosensitive member according to claim 1, a charging unit, an image exposing unit, a developing unit, and a transfer unit.   The image forming apparatus according to claim 14, wherein the charging unit is a charging unit that performs charging by a charging member disposed in contact with the charging unit.   A process cartridge that can be detachably attached to an image forming apparatus main body, wherein the electrophotographic photosensitive member and the charging unit, the image exposing unit, the developing unit, the transferring unit, and the fixing unit according to any one of claims 1 to 11. A process cartridge comprising a cartridge container and at least one means selected from the means and the cleaning means.   17. The process cartridge according to claim 16, wherein the charging unit is a charging unit that performs charging by a charging member disposed in contact therewith.   An image forming apparatus comprising the process cartridge according to claim 17.

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