JP4336557B2 - Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge having an electrophotographic photosensitive member, and an electrophotographic apparatus.

  In recent years, research and development of electrophotographic photoreceptors (organic electrophotographic photoreceptors) using organic photoconductive substances have been actively conducted.

  An electrophotographic photosensitive member basically includes a support and a photosensitive layer formed on the support. However, the current situation is that the surface of the support is coated with defects, the coating property of the photosensitive layer is improved, the adhesion between the support and the photosensitive layer is improved, the electrical damage of the photosensitive layer is protected, the charging property is improved, and the support is exposed to light. Various layers are often provided between the support and the photosensitive layer in order to improve the charge injection property to the layer. Therefore, the layer provided between the support and the photosensitive layer is required to have many functions such as covering property, adhesiveness, mechanical strength, electrical conductivity, and electrical barrier property.

Conventionally, the following types are known as layers provided between the support and the photosensitive layer.
(I) A resin layer not containing a conductive material.
(Ii) A resin layer containing a conductive material.
(Iii) A layer obtained by laminating the layer (i) above the layer (ii).

  Since the layer (i) does not contain a conductive material, the resistance of the layer is high. Moreover, in order to cover the defects on the surface of the support that has not been subjected to the surface smoothing treatment, the thickness (film thickness) must be increased.

  However, when the film thickness of the layer (i) having high resistance is increased, there arises a problem that the residual potential at the initial stage and repeated use is increased.

  Therefore, in order to put the layer (i) to practical use, it is necessary to reduce the defects on the surface of the support and reduce the film thickness.

  On the other hand, the layer (ii) is a layer in which a conductive material such as conductive particles is dispersed in a resin, and since the resistance of the layer can be reduced, the layer thickness is increased, It is possible to cover defects on the surface of a conductive support or a non-conductive support (such as a resin support).

  However, when the thickness of the layer (ii) is increased, it is necessary to impart sufficient conductivity to the layer as compared with the layer (i) to be reduced. Therefore, the layer (ii) In order to prevent charge injection from the substrate (ii) above to the photosensitive layer, which causes image defects, in a wide range of environmental conditions from low temperature and low humidity to high temperature and high humidity. It is preferable that a layer having an electrical barrier property is separately provided between the layer (ii) and the photosensitive layer. The layer having an electrical barrier property is a resin layer that does not contain conductive particles like the layer (i).

  That is, the layer provided between the support and the photosensitive layer preferably has the configuration (iii) in which the layer (i) and the layer (ii) are stacked.

  The structure of (iii) requires a plurality of layers to be formed, and thus the number of processes increases accordingly. However, since the allowable range of defects on the surface of the support is increased, the allowable use range of the support is greatly expanded, and production is performed. There is an advantage that improvement in performance can be achieved.

  In general, the layer (ii) is referred to as a conductive layer, and the layer (i) is referred to as an intermediate layer (undercoat layer, barrier layer).

Examples of the conductive material used for the conductive layer include various metals, metal oxides, and conductive polymers. Among these, tin oxide (hereinafter referred to as SnO ₂ ) having excellent resistance characteristics can be used in the production of SnO ₂ conductive materials, such as antimony oxide, from the ordinary powder resistivity of 10 ⁴ to 10 ⁶ Ω · cm. Mixing (doping) a metal compound or a nonmetallic element having a valence different from that of tin, reducing the powder resistivity to 1/1000 to 1/100000, or non-doping without increasing the constituent elements Thus, there is an oxygen deficient SnO ₂ conductive material in which the resistance of SnO ₂ is reduced to the same extent as antimony doping.

As a prior art related to oxygen deficient SnO ₂ , Japanese Patent Application Laid-Open No. 07-295245 (Patent Document 1) discloses a technique using oxygen deficient SnO ₂ for a conductive layer, and Japanese Patent Application Laid-Open No. 06-208238. publication (Patent Document 2), and coated with oxygen-deficient SnO ₂ in the barium sulfate particles than when using only SnO ₂ discloses a technique for improving the dispersibility, JP-a 10-186702 JP (Patent Document 3), although not disclosed up to the embodiment of oxygen-deficient SnO ₂ , in order to improve dispersibility, in order to improve the whiteness on the barium sulfate particles, A technique of coating SnO ₂ to coat titanium oxide (TiO ₂ ) and further impart electrical conductivity thereon has been disclosed.

  In recent years, the charging uniformity of the charging device has been improved and the need for pre-charging static elimination means (such as a pre-exposure device) to prevent charging unevenness from appearing in the output image has been diminished. Further, from the viewpoint of cost reduction, there is an increasing need for an electrophotographic apparatus having a configuration in which this is omitted.

  However, when the pre-charging neutralization means such as the pre-exposure device is omitted, the ghost image of the rotation cycle of the electrophotographic photosensitive member (on the halftone image, the exposure history of the electrophotographic photosensitive member one rotation before (solid black image, etc.) The phenomenon that appears) becomes prominent.

  This ghost phenomenon is thought to be partly due to the stagnation of charge (carrier) flow when an electrostatic latent image is formed on an electrophotographic photosensitive member. In a configuration with a conductive layer, there is no conductive layer. Since the number of layers is larger than that, the flow of electric charges (carriers) tends to stagnate accordingly.

  Until now, the ghost phenomenon could be almost eliminated by providing a pre-charge neutralization means such as a pre-exposure device to uniformly reduce the surface potential of the electrophotographic photosensitive member before charging. It was rarely highlighted as a technical issue. In other words, it has recently been found that the ghost phenomenon becomes prominent when there is no pre-charge neutralizing means such as a pre-exposure device.

As a prior art for improving the ghost phenomenon from the structure of the conductive layer, Japanese Patent Application Laid-Open No. 07-271072 (Patent Document 4) describes SnO ₂ having a reduced powder resistivity by doping with antimony oxide into TiO ₂ particles. A technique for increasing the content of a conductive material has been disclosed in order to use a coated conductive material and to smooth the flow of charges (carriers) in the conductive layer.
JP 07-295245 A Japanese Patent Laid-Open No. 06-208238 JP-A-10-186702 Japanese Patent Application Laid-Open No. 07-271072

However, the technique disclosed in Japanese Patent Application Laid-Open No. 07-271072 (Patent Document 4) is a technique for separately using an element called antimony in addition to tin as a material for coating TiO ₂ particles, so that the reusability is poor. There is an expectation for a technique using oxygen-deficient SnO ₂ having excellent reusability.

The object of the present invention is to cover defects on the surface of the support, to improve the coatability of the photosensitive layer, to improve the adhesion between the support and the photosensitive layer, to protect against electrical breakdown of the photosensitive layer, to improve the chargeability, from the support Even if the electrophotographic photosensitive member is provided with a conductive layer, an intermediate layer, and a photosensitive layer in this order on the support in order to improve the charge injection property to the photosensitive layer, the electrophotography in which the occurrence of the ghost phenomenon is suppressed The object is to provide a photoreceptor using oxygen-deficient SnO ₂ having excellent reusability.

  Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having such an electrophotographic photosensitive member.

The present invention is an electrophotographic photosensitive member having a conductive layer, an intermediate layer, and a photosensitive layer in this order on a support, wherein the conductive layer contains a binder resin and conductive particles.
The conductive particles are TiO ₂ particles coated with oxygen-deficient SnO ₂ ;
The average particle size of the conductive particles is 0.2 to 0.6 μm,
The volume resistivity of the conductive layer is Ri ^{5 × 10 5 ~8 × 10 8} Ω · cm der,
The average particle diameter (D [μm]) of the conductive particles and the mass ratio (P / B) of the conductive particles (P) and the binder resin (B) in the conductive layer are expressed by the following formula ( 1)
0.01 × (P / B) + 0.28 ≦ D ≦ 0.14 × (P / B) (1)
Which is an electrophotographic photosensitive member and said relationship near Rukoto satisfying.

  The present invention also provides a toner image by developing the electrophotographic photosensitive member, charging means for charging the surface of the electrophotographic photosensitive member, and developing an electrostatic latent image on the surface of the electrophotographic photosensitive member with toner. A developing means for transferring, a transferring means for transferring a toner image on the surface of the electrophotographic photosensitive member to a transfer material, and a cleaning means for cleaning the toner remaining on the surface of the electrophotographic photosensitive member after transfer It is a process cartridge characterized in that it supports at least one means selected as a unit and is detachable from the main body of the electrophotographic apparatus.

  The present invention also provides the above-described electrophotographic photosensitive member, charging means for charging the surface of the electrophotographic photosensitive member, and forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charging means by exposure. Exposure means for developing, developing means for developing an electrostatic latent image on the surface of the electrophotographic photosensitive member formed by the exposure means with toner to form a toner image, and electrophotography formed by the developing means An electrophotographic apparatus comprising transfer means for transferring a toner image on the surface of a photoreceptor to a transfer material.

According to the present invention, coating of defects on the surface of the support, improvement in coating properties of the photosensitive layer, improvement in adhesion between the support and the photosensitive layer, protection against electrical breakdown of the photosensitive layer, improvement in chargeability, Even if the electrophotographic photosensitive member is provided with a conductive layer, an intermediate layer, and a photosensitive layer in this order on the support in order to improve the charge injection property to the photosensitive layer, the electrophotography in which the occurrence of the ghost phenomenon is suppressed A photoreceptor can be provided using oxygen-deficient SnO ₂ having excellent reusability.

  Further, according to the present invention, a process cartridge and an electrophotographic apparatus having such an electrophotographic photosensitive member can be provided.

  Hereinafter, the present invention will be described in more detail.

  As described above, the electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor having a conductive layer, an intermediate layer, and a photosensitive layer in this order on a support. The conductive layer contains a binder resin and conductive particles.

Further, in the present invention, as the conductive particles, it was used TiO ₂ particles coated with SnO ₂ which attained low resistance (in powder resistivity 1/10000) by deficiency of oxygen. Oxygen deficient SnO ₂ is more reusable than SnO ₂ doped with a different element such as antimony.

The reason why the conductive particles used in the present invention are not particles composed only of oxygen-deficient SnO ₂ but TiO ₂ particles coated with oxygen-deficient SnO ₂ is as follows.

First, the core particles are used in order to improve the dispersibility of the conductive particles in the conductive layer. When a conductive layer coating solution is prepared using only oxygen-deficient SnO ₂ as the conductive particles, especially when the content ratio of oxygen-deficient SnO ₂ is high, aggregation of oxygen-deficient SnO ₂ is likely to occur.

Also, were used TiO ₂ particles as the core particles, the affinity of the oxide sites oxygen deficient SnO ₂ oxygen defect sites and TiO ₂ particle surface, binding the coating layer of the oxygen-deficient SnO ₂ and the core member This is because the oxygen deficient sites of oxygen deficient SnO ₂ are protected. Unlike the doped type, the oxygen deficient type may be oxidized in the presence of oxygen to lose the oxygen deficient site, resulting in a decrease in conductivity (increase in powder resistivity).

Further, when the exposure light (image exposure light) is laser light, the TiO ₂ particles that are the core material particles interfere with light reflected by the support surface during laser exposure, and interference fringes are generated in the output image. This can be suppressed.

Incidentally, (a method of coating the oxygen-deficient SnO ₂ to a method and TiO ₂ particles to produce an oxygen-deficient SnO ₂₎ oxygen-defective TiO ₂ particle production method of the SnO ₂ coated is, JP-A 07-295245 JP And Japanese Patent Laid-Open No. 04-154621.

In addition, when TiO ₂ particles coated with oxygen-deficient SnO ₂ are used as conductive particles containing the conductive layer, the volume resistivity of the conductive layer is 5 × 10 ⁵ in order to suppress the occurrence of the ghost phenomenon. ˜8 × 10 ⁸ Ω · cm, and the average particle size of the conductive particles needs to be 0.2 to 0.6 μm.

  First, the volume resistivity of the conductive layer will be described.

The ghost phenomenon is considered to be caused by a delay in the flow of charges (carriers) when an electrostatic latent image is formed on an electrophotographic photosensitive member. In order to suppress the occurrence of the phenomenon, it has been found that the resistance of the conductive layer needs to be 8 × 10 ⁸ Ω · cm or less in volume resistivity. On the other hand, it was found that when the resistance of the conductive layer is too low, the charging ability is decreased and the ghost phenomenon becomes conspicuous. Specifically, it has been found that the resistance of the conductive layer needs to be 5 × 10 ⁵ Ω · cm or more in terms of volume resistivity. In particular, the resistance of the conductive layer is preferably 2 × 10 ⁶ Ω · cm or more in volume resistivity.

  The method for measuring the volume resistivity of the conductive layer in the present invention is as follows.

  First, a conductive layer to be measured is formed on an aluminum sheet with a film thickness of about 2 to 5 μm, and a gold thin film is formed on the conductive layer by vapor deposition. The flowing current value was measured with a pA meter. The measurement environment is 23 ° C. and 60 RH%, and the applied voltage is 0.1V. A stable value 1 minute after the start of current value measurement was read, and the volume resistivity of the conductive layer was derived.

In order to keep the volume resistivity of the conductive layer in the above range, the powder resistivity of TiO ₂ particles coated with oxygen-deficient SnO ₂ that is conductive particles is 1 × 10 ^{−2 to} 5 × 10 ² Ω · It is preferably cm, and more preferably 1 × 10 ^{−2 to} 2.5 × 10 ² Ω · cm. If the powder resistivity is too high, it is difficult to keep the volume resistivity of the conductive layer within the above range, while if the powder resistivity is too low, the charging ability may be lowered.

In order to stably obtain TiO ₂ particles coated with oxygen-deficient SnO ₂ having a powder resistivity in the above range, the raw material blending ratio in producing the particles may be controlled. For example, it is calculated that 100% SnO ₂ can be obtained from a tin raw material, and the tin raw material necessary to produce 40-80% by mass of SnO ₂ with respect to TiO ₂ coated with oxygen-deficient SnO ₂ What is necessary is just to mix | blend at the time of particle | grain manufacture. In other words, the coverage of the oxygen-deficient SnO ₂ to TiO ₂ is preferably 40 to 80 wt%.

  The measurement method of the powder resistivity in the present invention is as follows.

As a measuring device, a resistance measuring device Loresta AP (Loresta Ap) manufactured by Mitsubishi Chemical Corporation was used. The powder to be measured (= particles) was hardened at a pressure of 500 kg / cm ² to obtain a pellet-shaped measurement sample. The measurement environment is 23 ° C. and 60% RH, and the applied voltage is 100V.

Next, the average particle diameter of TiO ₂ particles coated with oxygen-deficient SnO ₂ that is conductive particles will be described.

  Even if the composition of the conductive layer is the same, the powder resistivity of the conductive particles decreases as the average particle size of the conductive particles increases, and the volume resistivity of the conductive layer also decreases.

When the average particle diameter of the TiO ₂ particles coated with oxygen-deficient SnO ₂ that is conductive particles is less than 0.2 μm, in order to keep the volume resistivity of the conductive layer within the above range, the use amount of the conductive particles is increased. Although it is necessary, when the amount of the conductive particles used is increased, the surface roughness of the conductive layer suitable for suppressing the interference of light reflected on the surface of the conductive layer and generating interference fringes in the output image ( Rzjis: 1 to 3 μm) is difficult to achieve. Rzjis is defined as Rz in JISB0601 (1994). In JISB0601, Rz was revised by the 2001 standard revision, and replaced with Ry (maximum height) in 1994. Rz in 1994 was renamed Rzjis in 2001 for distinction.

On the other hand, when the average particle diameter of the TiO ₂ particles coated with oxygen-deficient SnO ₂ that is conductive particles exceeds 0.6 μm, the volume resistivity of the conductive layer decreases, but the effect of suppressing the occurrence of the ghost phenomenon is The image becomes thinner and the fog on the white background in the output image becomes noticeable.

  The measuring method of the average particle diameter in the present invention is as follows.

  Dispersion particles were measured by a liquid phase precipitation method using a conductive layer coating solution having a composition of only conductive particles. Specifically, the conductive layer coating solution was diluted with the solvent used therein, and the average particle size was measured using an ultracentrifugal automatic particle size distribution analyzer (CAPA700) manufactured by Horiba, Ltd.

In the present invention, the conductive layer is a conductive layer coating solution obtained by dispersing TiO ₂ particles coated with oxygen-deficient SnO ₂ having an average particle size of 0.2 to 0.6 μm together with a binder resin and a solvent. It is formed by coating on top and drying. Examples of the dispersion method include a method using a paint shaker, a sand mill, a ball mill, a liquid collision type high-speed disperser, and the like.

  Solvents used in the coating liquid for the conductive layer include alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether and propylene glycol monomethyl ether, , Esters such as methyl acetate and ethyl acetate, and aromatic hydrocarbons such as toluene and xylene.

  From the viewpoint of suppressing the occurrence of the ghost phenomenon, the thickness of the conductive layer is preferably 0.1 to 15 μm, more preferably 0.5 to 9 μm, and further preferably 0.5 to 4. More preferably, it is 5 μm.

  In the present invention, the film thickness of each layer of the electrophotographic photosensitive member including the conductive layer was measured by FISHERSPEPE mms manufactured by Fisher Instruments Co., Ltd.

  Examples of the binder resin for the conductive layer include phenol resin, polyurethane resin, polyamide resin, polyimide resin, polyamideimide resin, polyamic acid resin, polyvinyl acetal resin, epoxy resin, acrylic resin, melamine resin, and polyester resin. These can be used alone or in combination of two or more. In addition, among various resins, from the viewpoints of suppressing migration (melting) to other layers, adhesion to the support, dispersibility / dispersion stability of conductive particles, solvent resistance after film formation, etc., the conductive layer The binder resin is preferably a curable resin, and more preferably a thermosetting resin. Specifically, a thermosetting phenol resin, a polyurethane resin, or the like is preferable.

Moreover, the mass ratio (P / B) of the TiO ₂ particles coated with oxygen-deficient SnO ₂ having an average particle diameter of 0.2 to 0.6 μm, which is the conductive particles (P), and the binder resin (B) is It is preferable that it is 3.5 / 1-6/1. If the mass ratio (P / B) is too small, it will be difficult to keep the volume resistivity of the conductive layer in the above range, and if the mass ratio (P / B) is too large, the average particle diameter in the conductive layer will be 0.2 to Binding of TiO ₂ particles coated with 0.6 μm oxygen-deficient SnO ₂ becomes difficult.

Also, in order to suppress the occurrence of ghost phenomenon, and to suppress the occurrence of interference fringes in the output image due to interference of the light reflected from the surface of the conductive layer, the oxygen deficient type which is a conductive particle the average particle diameter of the TiO ₂ particles coated with SnO ₂ (D [μm]) and, TiO ₂ particles coated with oxygen-deficient SnO ₂ having an average particle diameter 0.2~0.6μm are conductive particles (P) The mass ratio (P / B) of the binder resin (B) preferably satisfies the following formula (1).
0.01 × (P / B) + 0.28 ≦ D ≦ 0.14 × (P / B) (1)
In the above formula (1), interference fringes are more likely to occur as the content of TiO ₂ particles coated with oxygen-deficient SnO ₂ that is conductive particles increases, while local from the conductive layer to the photosensitive layer. Therefore, the average particle diameter of the TiO ₂ particles coated with oxygen-deficient SnO ₂ can be controlled in accordance with the content of TiO ₂ particles coated with oxygen-deficient SnO ₂ in the conductive layer. It is preferable. Such a tendency was noticeable when the mass ratio (P / B) was 3.5 / 1 or more.

In addition, in order to suppress interference of light reflected on the surface of the conductive layer and generation of interference fringes in the output image, the conductive layer has an oxygen deficiency with a binder resin and an average particle size of 0.2 to 0.6 μm. In addition to the TiO ₂ particles coated with the type SnO ₂ , it is preferable to add a surface roughening agent for roughening the surface of the conductive layer. As the surface roughness imparting material, resin particles having an average particle diameter of 1 to 3 μm are preferable, and examples thereof include curable rubber, polyurethane resin, epoxy resin, alkyd resin, phenol resin, polyester resin, silicone resin, and acrylic-melamine resin. Examples include curable resin particles. Among these, silicone resin particles that are difficult to aggregate are preferable. Since the specific gravity (0.5 to 2) of the resin particles is smaller than the specific gravity (4 to 7) of the TiO ₂ particles coated with oxygen-deficient SnO ₂ , the surface of the conductive layer is efficiently formed when the conductive layer is formed. It can be roughened. However, since the volume resistivity of the conductive layer tends to increase as the content of the surface roughening agent in the conductive layer increases, in order to keep the volume resistivity of the conductive layer within the above range, The content of the surface roughening agent is preferably 20 to 35% by mass with respect to the binder resin in the conductive layer.

  Further, a leveling agent may be added to improve the surface property of the conductive layer, and pigment particles may be contained in the conductive layer in order to improve the concealing property of the conductive layer.

As described above, when the volume resistivity of the conductive layer is 5 × 10 ⁵ to 8 × 10 ⁸ Ω · cm, a decrease in charging ability is suppressed, or charge injection from the conductive layer to the photosensitive layer is prevented. In order to achieve this, it is necessary to provide an intermediate layer having an electrical barrier property between the conductive layer and the photosensitive layer. The volume resistivity of the intermediate layer is preferably 1 × 10 ⁹ to 1 × 10 ¹³ Ω · cm. If the volume resistivity of the intermediate layer is too small, the electrical barrier property becomes poor, and ghost phenomenon and fogging due to charge injection from the conductive layer tend to become remarkable. On the other hand, if the volume resistivity of the intermediate layer is too large, the flow of charges (carriers) is stagnant during image formation, and a ghost phenomenon and a rise in residual potential (lack of potential stability) tend to become remarkable.

  The method for measuring the volume resistivity of the intermediate layer in the present invention is as follows.

  First, an intermediate layer to be measured is formed on an aluminum sheet with a film thickness of about 2 to 5 μm, and a thin gold film is formed on the intermediate layer by vapor deposition. The flowing current value was measured with a pA meter. The measurement environment is 23 ° C. and 60 RH%, and the applied voltage is 100V. A stable value 1 minute after the start of current value measurement was read, and the volume resistivity of the intermediate layer was derived.

  The intermediate layer can be formed by applying an intermediate layer coating solution containing a binder resin onto the conductive layer and drying.

  As the binder resin for the intermediate layer, water-soluble resins such as polyvinyl alcohol, polyvinyl methyl ether, polyacrylic acids, methyl cellulose, ethyl cellulose, polyglutamic acid, casein, and starch, polyamide resins, polyimide resins, polyamideimide resins, and polyamic acid resins , Melamine resin, epoxy resin, polyurethane resin, polyglutamate resin and the like. In order to effectively develop the electrical barrier property, the binder resin of the intermediate layer is preferably a thermoplastic resin from the viewpoints of coatability, adhesion, solvent resistance, resistance, and the like. Specifically, a thermoplastic polyamide resin or the like is preferable. The polyamide resin is preferably a low crystalline or non-crystalline copolymer nylon that can be applied in a solution state. Moreover, it is preferable that the film thickness of an intermediate | middle layer is 0.1-2 micrometers.

  Further, in order to prevent the flow of electric charges (carriers) in the intermediate layer, the intermediate layer may contain an electron transport material (electron accepting material such as an acceptor).

  Next, the configuration of the electrophotographic photosensitive member of the present invention will be described.

  As shown in FIG. 1, the electrophotographic photosensitive member of the present invention has a conductive layer 102, an intermediate layer 103, and a photosensitive layer 104 (a charge generation layer 1041 and a charge transport layer 1042) on a support 101 in this order. Is the body.

  Even if the photosensitive layer is a single-layer type photosensitive layer 104 containing the charge transport material and the charge generation material in the same layer (see FIG. 1A), the charge generation layer 1041 containing the charge generation material and the charge transport material are transported. A multilayer (functional separation type) photosensitive layer separated into a charge transport layer 1042 containing a substance may be used, but a multilayer photosensitive layer is preferred from the viewpoint of electrophotographic characteristics. The laminated photosensitive layer includes a normal photosensitive layer (see FIG. 1B) in which the charge generation layer 1041 and the charge transport layer 1042 are laminated in this order from the support 101 side, and a charge transport layer from the support 101 side. Although there is a reverse type photosensitive layer (see FIG. 1C) in which 1042 and the charge generation layer 1041 are laminated in this order, the normal type photosensitive layer is preferable from the viewpoint of electrophotographic characteristics.

  In addition, a protective layer 105 may be provided over the photosensitive layer 104 (the charge generation layer 1041 and the charge transport layer 1042) (see FIG. 1D).

  As a support body, what has electroconductivity (conductive support body) is preferable, for example, metal supports, such as aluminum, an aluminum alloy, and stainless steel, can be used. In the case of aluminum and aluminum alloys, ED tube, EI tube, and these are cut, electrolytic composite polishing (electrolysis with electrode having electrolytic action and polishing with grinding stone having polishing action), wet or dry honing treatment Can also be used. In addition, the above metal support or resin support (polyethylene terephthalate, polybutylene terephthalate, phenol resin, polypropylene, polystyrene resin) having a layer formed by vacuum deposition of aluminum, aluminum alloy, indium oxide-tin oxide alloy, or the like. Etc.) can also be used. In addition, a support in which conductive particles such as carbon black, tin oxide particles, titanium oxide particles, and silver particles are impregnated with a resin or paper, a plastic having a conductive binder resin, or the like can also be used.

In order for the charge (carriers) of the conductive layer to flow to ground, the volume resistivity of the conductive support is also determined if the surface of the support is a layer provided to provide conductivity. The volume resistivity is preferably 1 × 10 ¹⁰ Ω · cm or less, and more preferably 1 × 10 ⁶ Ω · cm or less.

  When the support is a non-conductive support, it is necessary to adopt a configuration in which the ground is taken from the conductive layer of the electrophotographic photosensitive member of the present invention.

  A conductive layer is provided on the support, and an intermediate layer is provided on the conductive layer. The conductive layer and the intermediate layer are as described above.

  A photosensitive layer is provided on the intermediate layer.

  Examples of the charge generating material used in the electrophotographic photoreceptor of the present invention include azo pigments such as monoazo, disazo, and trisazo, phthalocyanine pigments such as metal phthalocyanine and nonmetal phthalocyanine, indigo pigments such as indigo and thioindigo, Perylene pigments such as perylene acid anhydride and perylene imide, polycyclic quinone pigments such as anthraquinone and pyrenequinone, squarylium dyes, pyrylium salts and thiapyrylium salts, triphenylmethane dyes, selenium, selenium-tellurium, amorphous Examples thereof include inorganic substances such as silicon, quinacridone pigments, azulenium salt pigments, cyanine dyes, xanthene dyes, quinoneimine dyes, styryl dyes, cadmium sulfide, and zinc oxide. Among these, metal phthalocyanines such as oxytitanium phthalocyanine, hydroxygallium phthalocyanine, and chlorogallium phthalocyanine are charge generating substances that are highly sensitive and easily generate ghosts, and are preferable because the present invention works more effectively. .

  When the photosensitive layer is a laminated photosensitive layer, examples of the binder resin used for the charge generation layer include polycarbonate resin, polyester resin, polyarylate resin, butyral resin, polystyrene resin, polyvinyl acetal resin, diallyl phthalate resin, and acrylic resin. Methacrylic resin, vinyl acetate resin, phenol resin, silicone resin, polysulfone resin, styrene-butadiene copolymer resin, alkyd resin, epoxy resin, urea resin, vinyl chloride-vinyl acetate copolymer resin, and the like. These can be used singly or in combination of two or more as a mixture or copolymer.

  The charge generation layer can be formed by applying and drying a charge generation layer coating solution obtained by dispersing a charge generation material together with a binder resin and a solvent. Examples of the dispersion method include a method using a homogenizer, an ultrasonic wave, a ball mill, a sand mill, an attritor, a roll mill and the like. The ratio between the charge generating material and the binder resin is preferably in the range of 10: 1 to 1:10 (mass ratio), and more preferably in the range of 3: 1 to 1: 1 (mass ratio).

  The solvent used in the coating solution for the charge generation layer is selected from the solubility and dispersion stability of the binder resin and charge generation material used, and the organic solvents include alcohols, sulfoxides, ketones, ethers, esters, aliphatic halogens. Hydrocarbons and aromatic compounds.

  In applying the charge generation layer coating solution, for example, a coating method such as a dip coating method, a spray coating method, a spinner coating method, a roller coating method, a Meyer bar coating method, a blade coating method, or the like can be used.

  The thickness of the charge generation layer is preferably 5 μm or less, and more preferably 0.1 to 2 μm.

  In addition, various sensitizers, antioxidants, ultraviolet absorbers, plasticizers, and the like can be added to the charge generation layer as necessary. Further, in order to prevent the flow of electric charges (carriers) in the charge generation layer, the charge generation layer may contain an electron transport material (electron accepting material such as an acceptor).

  Examples of the charge transport material used in the electrophotographic photoreceptor of the present invention include triarylamine compounds, hydrazone compounds, styryl compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, triallylmethane compounds, and the like.

  When the photosensitive layer is a laminated photosensitive layer, examples of the binder resin used for the charge transport layer include acrylic resin, styrene resin, polyester resin, polycarbonate resin, polyarylate resin, polysulfone resin, polyphenylene oxide resin, epoxy resin, Examples include polyurethane resins, alkyd resins, and unsaturated resins. In particular, polymethyl methacrylate resin, polystyrene resin, styrene-acrylonitrile copolymer resin, polycarbonate resin, polyarylate resin, diallyl phthalate resin and the like are preferable. These can be used singly or in combination of two or more as a mixture or copolymer.

  The charge transport layer can be formed by applying and drying a charge transport layer coating solution obtained by dissolving a charge transport material and a binder resin in a solvent. The ratio between the charge transport material and the binder resin is preferably in the range of 2: 1 to 1: 2 (mass ratio).

  Solvents used in the charge transport layer coating solution include ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, ethers such as dimethoxymethane and dimethoxyethane, aromatic hydrocarbons such as toluene and xylene, chlorobenzene and chloroform. In addition, a hydrocarbon substituted with a halogen atom such as carbon tetrachloride is used.

  When applying the charge transport layer coating solution, for example, a coating method such as a dip coating method, a spray coating method, a spinner coating method, a roller coating method, a Meyer bar coating method, a blade coating method, or the like can be used.

  The film thickness of the charge transport layer is preferably 5 to 40 μm, more preferably 10 to 30 μm, and more preferably in the range of 13 to 19 μm because ghosts hardly occur from the viewpoint of charging ability and electric field strength. Even more preferred.

  In addition, an antioxidant, an ultraviolet absorber, a plasticizer, and the like can be added to the charge transport layer as necessary.

  When the photosensitive layer is a single-layer type photosensitive layer, the single-layer type photosensitive layer is a coating for a single-layer type photosensitive layer obtained by dispersing the charge generation material and the charge transport material together with the binder resin and the solvent. It can be formed by applying a liquid and drying.

  Further, a protective layer may be provided on the photosensitive layer for the purpose of protecting the photosensitive layer. The protective layer can be formed by applying and drying a protective layer coating solution obtained by dissolving the various binder resins described above in a solvent.

  The thickness of the protective layer is preferably 0.5 to 10 μm, and particularly preferably 1 to 5 μm.

  FIG. 2 shows an example of a schematic configuration of an electrophotographic apparatus provided with the process cartridge of the present invention.

  In FIG. 2, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member, which is driven to rotate at a predetermined peripheral speed in the direction of the arrow about the shaft 2.

  The peripheral surface of the electrophotographic photosensitive member 1 that is driven to rotate is uniformly charged to a predetermined positive or negative potential by the charging unit 3, and then output from an exposure unit (not shown) such as slit exposure or laser beam scanning exposure. The exposure light (image exposure light) 4 is received. In this way, electrostatic latent images corresponding to the target image are sequentially formed on the peripheral surface of the electrophotographic photosensitive member 1. The voltage applied to the charging unit 3 may be only a DC voltage or a DC voltage on which an AC voltage is superimposed.

  The electrostatic latent image formed on the peripheral surface of the electrophotographic photosensitive member 1 is developed with toner of the developing unit 5 to become a toner image. Next, the toner image formed and supported on the peripheral surface of the electrophotographic photosensitive member 1 is transferred from the transfer material supply unit (not shown) by the transfer bias from the transfer unit (transfer roller) 6 to the electrophotographic photosensitive member 1 and the transfer unit. 6 (contact portion) is sequentially transferred onto a transfer material (paper or the like) P taken out and fed in synchronization with the rotation of the electrophotographic photosensitive member 1.

  The transfer material P that has received the transfer of the toner image is separated from the peripheral surface of the electrophotographic photosensitive member 1 and is introduced into the fixing means 8 to undergo image fixing, and is printed out of the apparatus as an image formed product (print, copy). Be out.

  The peripheral surface of the electrophotographic photosensitive member 1 after the transfer of the toner image is cleaned by receiving the transfer residual toner by a cleaning means (cleaning blade or the like) 7.

  Among the above-described components such as the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, the transfer unit 6 and the cleaning unit 7, a plurality of components are housed in a container and integrally combined as a process cartridge. The process cartridge may be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. In FIG. 2, the electrophotographic photosensitive member 1, the contact charging means 3, the developing means 5 and the cleaning means 7 are integrally supported to form a cartridge, and electrophotographic using a guide means 10 such as a rail of the electrophotographic apparatus main body. The process cartridge 9 is detachable from the apparatus main body.

The following, more detailed explanation of the present invention by way of specific examples. However, the present invention is not limited to these. In the examples, “part” means “part by mass”.

Example 1
Supports an aluminum cylinder (JIS-A3003, aluminum alloy ED tube, manufactured by Showa Aluminum Co., Ltd.) with a length of 260.5 mm and a diameter of 30 mm obtained by hot extrusion in an environment of 23 ° C. and 60% RH. The body. The Rzjis on the support surface was measured and found to be 0.8 μm.

  In the present invention, Rzjis is measured according to JIS-B0601 (1994), using a surface roughness meter Surfcoder SE3500 manufactured by Kosaka Laboratory Ltd., with a feed rate of 0.1 mm / s and a cutoff λc of 0.8 mm. The measurement length was set to 2.50 mm.

Next, TiO ₂ particles coated with oxygen-deficient SnO ₂ as conductive particles (powder resistivity 80 Ω · cm, SnO ₂ coverage (mass ratio) 50%) 7.90 parts, as binder resin Phenol resin (trade name: Priorofen J-325, manufactured by Dainippon Ink & Chemicals, Inc., resin solid content 60%) 3.30 parts, 8.60 parts of methoxypropanol as a solvent, 1 mm diameter glass beads The dispersion was prepared by dispersing for 3 hours in a sand mill using

The average particle diameter of TiO ₂ particles coated with oxygen-deficient SnO ₂ in this dispersion was 0.45 μm.

  In this dispersion, 0.5 parts of silicone resin particles (trade name: Tospearl 120, manufactured by GE Toshiba Silicone Co., Ltd., average particle diameter 2 μm) as a surface roughness imparting agent, silicone oil (trade name: product name: 0.001 part of SH28PA (Toray Dow Corning Silicone Co., Ltd.) was added and stirred to prepare a conductive layer coating solution.

  This conductive layer coating solution was dip coated on a support in an environment of 23 ° C. and 60% RH, dried at 140 ° C. for 30 minutes, and thermally cured to form a conductive layer having a thickness of 4 μm. When Rzjis on the surface of the conductive layer was measured, it was 1.5 μm.

Separately, this conductive layer coating solution was applied to an aluminum sheet with a Meyer bar to a thickness of 4 μm and dried to prepare a sample for measuring the conductive layer volume resistivity. When a gold thin film was formed on the conductive layer by vapor deposition and the volume resistivity of the conductive layer was measured, it was 5.5 × 10 ⁷ Ω · cm.

  Next, on the conductive layer, 4 parts of N-methoxymethylated nylon (trade name: Toresin EF-30T, manufactured by Teikoku Chemical Industry Co., Ltd.) and 2 parts of copolymer nylon resin (Amilan CM8000, manufactured by Toray Industries, Inc.) Is coated with an intermediate layer coating solution obtained by dissolving in a mixed solvent of 65 parts methanol / 30 parts n-butanol and dried at 100 ° C. for 10 minutes to form an intermediate layer having a thickness of 0.5 μm. Formed.

Separately, this intermediate layer coating solution was applied onto an aluminum sheet with a Meyer bar to a thickness of 3 μm and dried to prepare a sample for measuring the intermediate layer volume resistivity. When a gold thin film was formed on the intermediate layer by vapor deposition and the volume resistivity of the intermediate layer was measured, it was 5 × 10 ¹¹ Ω · cm.

  Next, the Bragg angles (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction are 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 °, and 28.3 °. Sand mill apparatus using 10 parts of glass beads having a diameter of 1 mm, 10 parts of crystalline hydroxygallium phthalocyanine having a strong peak, 5 parts of polyvinyl butyral (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 250 parts of cyclohexanone And then, 250 parts of ethyl acetate was added to prepare a charge generation layer coating solution.

  This charge generation layer coating solution was dip coated on the intermediate layer and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.16 μm.

  Next, 10 parts of an amine compound having a structure represented by the following formula, and

10 parts of polycarbonate resin (trade name: Z400, manufactured by Mitsubishi Engineering Plastics) was dissolved in a mixed solvent of 30 parts of dimethoxymethane / 70 parts of chlorobenzene to prepare a coating solution for a charge transport layer.

  The charge transport layer coating solution was dip coated on the charge generation layer and dried at 120 ° C. for 30 minutes to form a charge transport layer having a thickness of 17 μm.

  In this manner, an electrophotographic photoreceptor having a charge transport layer as a surface layer was produced.

  The produced electrophotographic photosensitive member is mounted on a laser beam printer LBP-2510 manufactured by Canon Inc. with the pre-exposure unit turned off at 15 ° C. and 10% RH. Evaluation of the image after the paper output and measurement of the surface potential on the electrophotographic photosensitive member were performed. Details are as follows.

  The produced electrophotographic photosensitive member was mounted on a cyan process cartridge of LBP-2510, and mounted on a cyan process cartridge station for evaluation.

  At the time of paper passing, a full-color printing operation was performed in an intermittent mode in which a character image having a printing rate of 2% for each color was output on a letter paper sheet every 20 seconds, and 3000 images were output.

  Then, four images (solid white, ghost chart, solid black, halftone image of Keima pattern) for image evaluation were output at the start of evaluation and at the end of 3000.

  Note that the ghost chart is a print image writing position in which a range of 30 mm from the print image writing position (upper edge of paper 10 mm) is placed on a solid white background with 25 mm square solid black squares arranged at equal intervals and parallel to the print image writing position. The chart after 30 mm from the position is a chart for printing a halftone of a Keima pattern (a halftone image in which a Shogi Keima pattern (a pattern in which 2 dots are printed on 6 squares) is repeated).

  The criteria for image evaluation are as follows.

  The presence / absence of a ghost was determined from the ghost chart as follows: A: no ghost, B: almost no ghost, C: little ghost observed, D: ghost observed, E: ghost clearly understood .

  The presence / absence of interference fringes was determined as follows: A: no interference fringes, C: slight interference fringes observed, and D: interference fringes observed from the halftone image of the Keima pattern.

  The fog and potty were evaluated from solid white images. If there is no occurrence of fog or spots, nothing is stated.

  In addition, after outputting a sample for image evaluation, an apparatus for measuring the surface potential of the electrophotographic photosensitive member (an apparatus in which a probe for measuring the surface potential of the electrophotographic photosensitive member is installed at the developing roller position of the process cartridge (toner, The developing roller and the cleaning blade were removed), and the ghost potential was measured with the electrophotographic photosensitive member mounted and the electrostatic transfer belt unit of LBP-2510 removed.

  The method for measuring the ghost potential is as follows.

  First, letter paper size ghost potential measurement chart (in the range of 25 mm from the print image writing (upper edge 10 mm) position is solid black, in the range of 25-30 mm from the print image writing position is solid white, from the print image writing position. After 30 mm, the surface potential of the electrophotographic photosensitive member was measured at a cyan process cartridge station in a non-sheet-passing printing mode (repetitive halftone of the Keima pattern).

  Next, the difference between the halftone potential after one rotation of solid black and the halftone potential before and after that (the halftone potential after one rotation of solid black is smaller than the halftone potential immediately before and after one rotation of solid black) is the ghost potential. It was.

  The results are shown in Table 1.

(Example 2)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The amount of TiO ₂ particles coated with oxygen-deficient SnO ₂ as the conductive particles of the conductive layer was changed to 7.63 parts, and the amount of phenol resin used as the binder resin for the conductive layer was changed to 3.75 parts. . As a result, Rzjis on the surface of the conductive layer was 1.7 μm, and the volume resistivity of the conductive layer was 8 × 10 ⁸ Ω · cm.

(Example 3)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The amount of TiO ₂ particles coated with oxygen-deficient SnO ₂ as the conductive particles of the conductive layer was changed to 7.73 parts, and the amount of phenol resin used as the binder resin of the conductive layer was changed to 3.58 parts. . As a result, Rzjis on the surface of the conductive layer was 1.6 μm, and the volume resistivity of the conductive layer was 9 × 10 ⁷ Ω · cm.

Example 4
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The amount of TiO ₂ particles coated with oxygen-deficient SnO ₂ as the conductive particles of the conductive layer was changed to 8.40 parts, and the amount of phenol resin used as the binder resin for the conductive layers was changed to 2.46 parts. . As a result, Rzjis on the surface of the conductive layer was 1.5 μm, and the volume resistivity of the conductive layer was 2 × 10 ⁶ Ω · cm.

(Example 5)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The amount of TiO ₂ particles coated with oxygen-deficient SnO ₂ as conductive particles of the conductive layer was changed to 8.51 parts, and the amount of phenol resin used as the binder resin of the conductive layer was changed to 2.28 parts. . As a result, Rzjis on the surface of the conductive layer was 1.4 μm, and the volume resistivity of the conductive layer was 5 × 10 ⁵ Ω · cm.

(Example 6)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
TiO ₂ particles coated with oxygen-deficient SnO ₂ on the conductive particles of the conductive layer (powder resistivity 40 Ω · cm, SnO ₂ coverage (mass ratio) 60%) were changed to 8.08 parts, The amount of phenol resin used as the binder resin for the conductive layer was changed to 3.00 parts. The average particle diameter of the TiO ₂ particles coated with this oxygen-deficient SnO ₂ was 0.46 μm. As a result, Rzjis on the surface of the conductive layer was 1.5 μm, and the volume resistivity of the conductive layer was 4 × 10 ⁷ Ω · cm.

(Reference Example 7)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The conductive particles of the conductive layer were changed to 7.90 parts of TiO ₂ particles coated with oxygen-deficient SnO ₂ (powder resistivity 600Ω · cm, SnO ₂ coverage (mass ratio) 35%). The average particle diameter of the TiO ₂ particles coated with the oxygen-deficient SnO ₂ was 0.22 μm. As a result, Rzjis on the surface of the conductive layer was 1.05 μm, and the volume resistivity of the conductive layer was 2 × 10 ⁸ Ω · cm.

(Reference Example 8)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The conductive particles of the conductive layer were changed to 7.90 parts of TiO ₂ particles coated with oxygen-deficient SnO ₂ (powder resistivity 400 Ω · cm, SnO ₂ coverage (mass ratio) 40%). The average particle diameter of the TiO ₂ particles coated with the oxygen-deficient SnO ₂ was 0.30 μm. As a result, Rzjis on the surface of the conductive layer was 1.15 μm, and the volume resistivity of the conductive layer was 1.5 × 10 ⁸ Ω · cm.

Example 9
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The conductive particles of the conductive layer were changed to 7.90 parts of TiO ₂ particles coated with oxygen-deficient SnO ₂ (powder resistivity 100 Ω · cm, SnO ₂ coverage (mass ratio) 50%). The average particle diameter of the TiO ₂ particles coated with the oxygen-deficient SnO ₂ was 0.33 μm. As a result, Rzjis on the surface of the conductive layer was 1.2 μm, and the volume resistivity of the conductive layer was 7 × 10 ⁷ Ω · cm.

(Example 10)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The conductive particles of the conductive layer were changed to 7.90 parts of TiO ₂ particles coated with oxygen-deficient SnO ₂ (powder resistivity 40 Ω · cm, SnO ₂ coverage (mass ratio) 75%). The average particle diameter of the TiO ₂ particles coated with this oxygen-deficient SnO ₂ was 0.55 μm. As a result, Rzjis on the surface of the conductive layer was 1.6 μm, and the volume resistivity of the conductive layer was 3 × 10 ⁷ Ω · cm.

(Reference Example 11)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The conductive particles of the conductive layer were changed to 7.90 parts of TiO ₂ particles coated with oxygen-deficient SnO ₂ (powder resistivity 0.5 Ω · cm, SnO ₂ coverage (mass ratio) was 85%). The average particle diameter of the TiO ₂ particles coated with this oxygen-deficient SnO ₂ was 0.58 μm. As a result, Rzjis on the surface of the conductive layer was 1.65 μm, and the volume resistivity of the conductive layer was 8 × 10 ⁶ Ω · cm.

(Example 12)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
First, the support was changed to the following cutting tube.

  An aluminum base tube (JIS-A6063) having an outer diameter of 30.5 mm, an inner diameter of 28.5 mm, a length of 260.5 mm, a runout accuracy of 100 μm, and a Rzjis of 10 μm obtained by hot extrusion is mounted on a lathe and diamond sintered. Cutting was performed with a cutting tool so that the outer diameter was 30.0 ± 0.02 mm, the runout accuracy was 15 μm, and Rzjis was 0.5 μm, to obtain a cutting tube having Rzjis of 0.5 μm. At this time, the rotation speed of the spindle was 3000 rpm, the feeding speed of the cutting tool was 0.3 mm / rev, and the machining time was 24 seconds except for the attachment / detachment of the workpiece. Moreover, the film thickness of the conductive layer was changed to 0.4 μm.

  As a result, Rzjis on the surface of the conductive layer was 2.2 μm.

(Example 13)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
First, the support was subjected to a wet honing treatment on an aluminum cylinder of JIS-A3003 under the following conditions (using a wet honing apparatus manufactured by Fuji Seiki Co., Ltd.), and the surface Rzjis was 2.0 μm. It changed to what became.
-Honing conditions-
Abrasive abrasive grains: spherical alumina beads having an average particle diameter of 30 μm (trade name: CB-A30S, manufactured by Showa Denko KK)
Suspension medium: water abrasive grains / suspension medium = 1/9 (volume ratio)
Number of rotations of aluminum cylinder: 1.67 s ⁻¹
Air blowing pressure: 0.165 MPa
Gun moving speed: 13.3 mm / s
Distance between gun nozzle and aluminum cylinder: 180mm
Abrasive abrasive particle discharge angle: 45 °
Polishing liquid (abrasive abrasive grains and suspension medium): Number of times of projection: once The film thickness of the conductive layer was changed to 0.6 μm.

  As a result, Rzjis on the surface of the conductive layer was 1.9 μm.

(Example 14)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The film thickness of the conductive layer was changed to 4.4 μm. As a result, Rzjis on the surface of the conductive layer was 1.5 μm.

(Example 15)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The film thickness of the conductive layer was changed to 4.7 μm. As a result, Rzjis on the surface of the conductive layer was 1.5 μm.

(Example 16)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The film thickness of the conductive layer was changed to 8.5 μm. As a result, Rzjis on the surface of the conductive layer was 1.3 μm.

(Example 17)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The binder resin of the conductive layer was changed to 3.30 parts of polyester polyurethane (trade name: Nipponporan 2304, manufactured by Nippon Polyurethane Co., Ltd., solid content 70%), and the film thickness of the conductive layer was changed to 9.5 μm. . As a result, Rzjis on the surface of the conductive layer was 1.3 μm, and the volume resistivity of the conductive layer was 5.5 × 10 ⁸ Ω · cm.

(Example 18)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The amount of the silicone resin particles used as the surface roughness imparting agent for the conductive layer was changed to 0.38 parts. As a result, Rzjis on the surface of the conductive layer was 0.95 μm, and the volume resistivity of the conductive layer was 5.5 × 10 ⁷ Ω · cm.

(Example 19)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The amount of silicone resin particles used as the surface roughening imparting agent for the conductive layer was changed to 0.41 part. As a result, Rzjis on the surface of the conductive layer was 1.1 μm, and the volume resistivity of the conductive layer was 5.5 × 10 ⁷ Ω · cm.

(Example 20)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The amount of silicone resin particles used as the surface roughness imparting agent for the conductive layer was changed to 0.68 parts. As a result, Rzjis on the surface of the conductive layer was 1.8 μm, and the volume resistivity of the conductive layer was 5.5 × 10 ⁷ Ω · cm.

(Example 21)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The surface roughness imparting material of the conductive layer was changed to 0.71 part of silicone resin particles (trade name: Tospearl 145, manufactured by GE Toshiba Silicone Co., Ltd.). The average particle diameter of the silicone resin particles was 4.5 μm. As a result, Rzjis on the surface of the conductive layer was 1.9 μm, and the volume resistivity of the conductive layer was 5.5 × 10 ⁷ Ω · cm.

(Example 22)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The film thickness of the intermediate layer was changed to 0.07 μm, and the film thickness of the charge transport layer was changed to 20 μm.

(Example 23)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The film thickness of the intermediate layer was changed to 0.15 μm, and the film thickness of the charge transport layer was changed to 18 μm.

(Example 24)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The film thickness of the intermediate layer was changed to 1.8 μm, and the film thickness of the charge transport layer was changed to 13 μm.

(Example 25)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 1.
The film thickness of the intermediate layer was changed to 2.2 μm, and the film thickness of the charge transport layer was changed to 12 μm.

(Example 26)
In Example 1, the binder resin of the charge transport layer is a polyarylate resin having a repeating structural unit represented by the following formula (viscosity average molecular weight (Mv): 42000).

An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the above was changed. The polyarylate resin having a repeating structural unit represented by the above formula has a molar ratio of terephthalic acid structure to isophthalic acid structure (terephthalic acid structure: isophthalic acid structure) of 50:50 (molar ratio).

  In addition, the measuring method of a viscosity average molecular weight (Mv) is as follows.

  First, 0.5 g of a sample was dissolved in 100 ml of methylene chloride, and the specific viscosity at 25 ° C. was measured using a modified Ubbelode viscometer. Next, the intrinsic viscosity was determined from this specific viscosity, and the viscosity average molecular weight (Mv) was calculated by the Mark-Houwink viscosity equation. The viscosity average molecular weight (Mv) was a polystyrene conversion value measured by GPC (gel permeation chromatography).

  The prepared electrophotographic photoreceptor is mounted on an LBP-1760 of a laser beam printer manufactured by Canon Inc. which does not have a pre-exposure device in an environment of 15 ° C. and 10% RH, and the initial and 3000 sheets are output. Later evaluation of the image and measurement of the surface potential on the electrophotographic photosensitive member were performed. Details are as follows.

  The produced electrophotographic photosensitive member was attached to the process cartridge of LBP-1760 and evaluated.

  When the paper was passed, a printing operation was performed in an intermittent mode in which a character image with a printing rate of 2% was output on a letter paper sheet every 15 seconds, and 3000 images were output.

  Then, four images (solid white, ghost chart, solid black, halftone image of Keima pattern) for image evaluation were output at the start of evaluation and at the end of 3000.

  The ghost chart and the Keima pattern are the same as those in the first embodiment.

  The criteria for image evaluation are the same as in the first embodiment.

  Further, after outputting a sample for image evaluation, an apparatus for measuring the surface potential of the electrophotographic photosensitive member (an apparatus in which a probe for measuring the surface potential of the electrophotographic photosensitive member is installed at the developing sleeve position of the process cartridge (toner, The developing sleeves and the cleaning blade were removed)), the electrophotographic photosensitive member was mounted, the transfer roller of LBP-1760 was removed, and the ghost potential was measured in a non-sheet passing state.

  The method for measuring the ghost potential is the same as in the first embodiment.

  The results are shown in Table 1.

(Comparative Example 1)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 2.
TiO ₂ particles coated with oxygen-deficient SnO ₂ on the conductive particles of the conductive layer (powder resistivity 0.5 Ω · cm, SnO ₂ coverage (mass ratio) 80%) were changed to 8.36 parts, In addition, the amount of phenol resin used as the binder resin for the conductive layer was changed to 2.53 parts. The average particle diameter of the TiO ₂ particles coated with the oxygen-deficient SnO ₂ was 0.6 μm. As a result, Rzjis on the surface of the conductive layer was 1.4 μm, and the volume resistivity of the conductive layer was 4 × 10 ⁵ Ω · cm.

(Comparative Example 2)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 2.
The conductive particles of the conductive layer were changed to 7.41 parts of TiO ₂ particles coated with oxygen-deficient SnO ₂ (powder resistivity 400 Ω · cm, SnO ₂ coverage (mass ratio) 50%), The amount of phenol resin used as the binder resin for the conductive layer was changed to 4.12 parts. The average particle diameter of the TiO ₂ particles coated with the oxygen-deficient SnO ₂ was 0.2 μm. As a result, Rzjis on the surface of the conductive layer was 0.9 μm, and the volume resistivity of the conductive layer was 1 × 10 ⁹ Ω · cm.

(Comparative Example 3)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 2.
TiO ₂ particles coated with oxygen-deficient SnO ₂ with respect to the conductive particles of the conductive layer (powder resistivity 800Ω · cm, SnO ₂ coverage (mass ratio) 40%) were changed to 7.68 parts, The amount of phenol resin used as the binder resin for the conductive layer was changed to 3.66 parts. The average particle diameter of the TiO ₂ particles coated with this oxygen-deficient SnO ₂ was 0.18 μm. As a result, Rzjis on the surface of the conductive layer was 0.85 μm, and the volume resistivity of the conductive layer was 7 × 10 ⁸ Ω · cm.

(Comparative Example 4)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 2.
The conductive particles of the conductive layer were changed to 7.90 parts of TiO ₂ particles coated with oxygen-deficient SnO ₂ (powder resistivity 10 Ω · cm, SnO ₂ coverage (mass ratio) 50%). The average particle diameter of the TiO ₂ particles coated with the oxygen-deficient SnO ₂ was 0.63 μm. As a result, Rzjis on the surface of the conductive layer was 1.6 μm, and the volume resistivity of the conductive layer was 6 × 10 ⁵ Ω · cm.

(Comparative Example 5)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 2.
TiO ₂ particles coated with SnO ₂ doped with 10% by mass of antimony oxide with respect to the conductive particles of the conductive layer (powder resistivity 10 Ω · cm, SnO ₂ coverage (mass ratio) 50%) 7.90 parts Changed to The average particle diameter of the TiO ₂ particles coated with SnO ₂ containing 10% by mass of antimony oxide was 0.63 μm. As a result, Rzjis on the surface of the conductive layer was 1.6 μm, and the volume resistivity of the conductive layer was 5 × 10 ⁵ Ω · cm.

(Comparative Example 6)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 2.
The conductive particles of the conductive layer were changed to 7.90 parts of barium sulfate particles coated with oxygen-deficient SnO ₂ (powder resistivity 950 Ω · cm, SnO ₂ coverage (mass ratio) 30%). The film thickness was changed to 6 μm. The average particle diameter of the barium sulfate particles coated with the oxygen-deficient SnO ₂ was 0.18 μm. As a result, Rzjis on the surface of the conductive layer was 0.85 μm, and the volume resistivity of the conductive layer was 7 × 10 ⁸ Ω · cm.

(Comparative Example 7)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 2.
TiO ₂ particles coated with SnO _{2 on} which the conductive particles of the conductive layer are not doped or oxygen deficient (powder resistivity 80000 Ω · cm, SnO ₂ coverage (mass ratio) is 50%) 7.90 Changed to the department. The average particle diameter of the TiO ₂ particles coated with SnO ₂ not subjected to the doping treatment or the oxygen deficiency treatment was 0.45 μm. As a result, Rzjis on the surface of the conductive layer was 1.5 μm, and the volume resistivity of the conductive layer was 6 × 10 ¹⁰ Ω · cm.

(Comparative Example 8)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the following points were changed. The results are shown in Table 2.
The conductive particles of the conductive layer were changed to 7.90 parts of particles in which oxygen-deficient SnO ₂ aggregated (powder resistivity 0.5 Ω · cm, no core particles). The average particle diameter of the particles in which the oxygen-deficient SnO ₂ aggregated was 0.65 μm. As a result, Rzjis on the surface of the conductive layer was 1.6 μm, and the volume resistivity of the conductive layer was 5 × 10 ⁶ Ω · cm.

  In the present invention, the film thickness and the surface roughness are average values in a region of ± 25 mm in the central portion in the longitudinal direction of the electrophotographic photosensitive member.

As can be seen from the above results, according to the present invention, it is possible to cover defects on the support surface, improve the coating property of the photosensitive layer, improve the adhesion between the support and the photosensitive layer, protect against electrical breakdown of the photosensitive layer, Even if the electrophotographic photosensitive member is provided with a conductive layer, an intermediate layer, and a photosensitive layer in this order on the support in order to improve chargeability and charge injection from the support to the photosensitive layer, the ghost phenomenon It is possible to provide an electrophotographic photosensitive member in which the generation of oxygen is suppressed using oxygen-deficient SnO ₂ having excellent reusability.

  Further, according to the present invention, a process cartridge and an electrophotographic apparatus having such an electrophotographic photosensitive member can be provided.

An example of the layer structure of the electrophotographic photosensitive member of the present invention will be shown. 1 shows an example of a schematic configuration of an electrophotographic apparatus provided with a process cartridge of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Support body 102 Conductive layer 103 Intermediate layer 104 Photosensitive layer 1041 Charge generation layer 1042 Charge transport layer 105 Protective layer 1 Electrophotographic photosensitive member 2 Axis 3 Charging means (primary charging means)
4 exposure light (image exposure light)
5 Developing means 6 Transfer means (transfer roller)
7 Cleaning means (cleaning blade)
8 Fixing means 9 Process cartridge 10 Guide means P Transfer material (paper, etc.)

Claims (10)

An electrophotographic photosensitive member having a conductive layer, an intermediate layer, and a photosensitive layer in this order on a support, wherein the conductive layer contains a binder resin and conductive particles.
The conductive particles are TiO ₂ particles coated with oxygen-deficient SnO ₂ ;
The average particle size of the conductive particles is 0.2 to 0.6 μm,
The volume resistivity of the conductive layer is Ri ^{5 × 10 5 ~8 × 10 8} Ω · cm der,
The average particle diameter (D [μm]) of the conductive particles and the mass ratio (P / B) of the conductive particles (P) and the binder resin (B) in the conductive layer are expressed by the following formula ( 1)
0.01 × (P / B) + 0.28 ≦ D ≦ 0.14 × (P / B) (1)
An electrophotographic photosensitive member, wherein a relationship near Rukoto satisfying. Before Kishitsu weight ratio (P / B) electrophotographic photosensitive member according to claim 1 which is 3.5 / 1-6 / 1. The electrophotographic photosensitive member according to claim 1, wherein the conductive particles have a powder resistivity of 1 × 10 ^{−2 to} 5 × 10 ² Ω · cm.   The electrophotographic photosensitive member according to claim 1, wherein the conductive layer has a thickness of 0.5 to 9 μm.   The electrophotographic photosensitive member according to claim 4, wherein the conductive layer has a thickness of 0.5 to 4.5 μm. The binder resin contained in the conductive layer is a curable resin, and, according to any one of claims 1 to 5, wherein the conductive layer contains 20 to 35 wt% of the resin particles relative to the curable resin Electrophotographic photoreceptor. An electrophotographic photosensitive member according to any one of claims 1 to 6 charging unit for charging the surface of the electrophotographic photosensitive member, an electrostatic latent image on the surface of the electrophotographic photosensitive member is developed with toner Toner Developing means for forming an image, transfer means for transferring a toner image on the surface of the electrophotographic photosensitive member to a transfer material, and cleaning for cleaning toner remaining on the surface of the electrophotographic photosensitive member after transfer A process cartridge which integrally supports at least one means selected from the group consisting of means and is detachable from the main body of the electrophotographic apparatus. The electrophotographic photosensitive member according to any one of claims 1 to 6 charging unit for charging the surface of the electrophotographic photosensitive member, an electrostatic latent by exposure to the surface of the charged electrophotographic photoconductor by the charging means An exposure means for forming an image, a developing means for developing an electrostatic latent image on the surface of the electrophotographic photosensitive member formed by the exposure means with toner to form a toner image, and a developing means An electrophotographic apparatus comprising transfer means for transferring a toner image on the surface of the electrophotographic photosensitive member to a transfer material. 9. The electrophotographic apparatus according to claim 8 , wherein the electrophotographic apparatus does not have a pre-charging neutralization unit for neutralizing a surface of the electrophotographic photosensitive member after the transfer by the transfer unit and before the charging by the charging unit. The electrophotographic apparatus according to claim 8 or 9 , wherein the exposure means is a means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member by laser exposure.

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