JP2003021924A - Electrophotographic photoreceptor, electrophotographic apparatus and process cartridge - Google Patents

Abstract

(57) [Problem] To provide a high durability while maintaining the advantages that the charging voltage is only the desired surface potential of the photoreceptor, no ozone or charging noise is generated, the device configuration is low power, and the device is simple. Electrophotographic photosensitive member, electrophotographic apparatus and process cartridge. SOLUTION: The electrophotographic photoreceptor has on a conductive support a photosensitive layer containing at least one kind of charge transporting material of formula (1), (2) or (3) and a surface containing conductive particles. An electrophotographic photosensitive member, an electrophotographic apparatus, and a process cartridge having a protective layer. Embedded image (Wherein, Ar _{1 to} Ar ₁₂ represent an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, and the like)

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus and a process cartridge, and more particularly to an electrophotographic photoreceptor having a photosensitive layer containing a specific charge transport material and a surface protective layer containing conductive particles. , A process cartridge that performs specific charging.

[0002]

2. Description of the Related Art Conventionally, for example, in an electrophotographic apparatus,
A corona charger (corona discharge device) is used as a charging device for uniformly charging (including static elimination) an image carrier (charged body) such as an electrophotographic photoreceptor or an electrostatic recording dielectric to a predetermined polarity and potential. Electric appliances) were widely used.

The corona charger is a non-contact type charging device, which is provided with a discharge electrode such as a wire electrode and a shield electrode surrounding the discharge electrode, and the discharge opening is made to face the image carrier, which is a member to be charged, and is not in contact. And is exposed to the discharge current (corona shower) generated by applying a high voltage to the discharge electrode and the shield electrode on the surface of the image carrier to charge the surface of the image carrier in a predetermined manner.

In recent years, in the electrophotographic apparatus of medium and low speed models, contact charging is performed as a charging device for a charged member such as an image carrier because it has advantages such as low ozone and low power as compared with a corona charger. Many devices have been proposed and put into practical use.

The contact charging device is a conductive charging member (contact charging member / contact charger) of a roller type (charging roller), a fur brush type, a magnetic brush type, a blade type, etc. ) Is contacted and a predetermined charging bias is applied to the contact charging member to charge the surface of the body to be charged to a predetermined polarity and potential.

Charging mechanism of contact charging (charging mechanism,
In (charging principle), two types of charging mechanism (1) discharge charging system and (2) injection charging system coexist, and each characteristic appears depending on which one is dominant.

(1) The discharge charging system is a system in which the surface of an object to be charged is charged by a discharge phenomenon occurring in a minute gap between the contact charging member and the object to be charged.

Since the discharge charging system has a constant discharge threshold between the contact charging member and the member to be charged, it is necessary to apply a voltage higher than the charging potential to the contact charging member. Further, although the amount of generation is much smaller than that of the corona charger, the generation of discharge products is inevitable in principle, so that the harmful effect of active ions such as ozone is unavoidable.

(2) The injection charging system is a system in which charges are directly injected from the contact charging member to the body to be charged so that the surface of the body to be charged is charged.

It is called injection charging or direct charging. More specifically, a medium-resistance contact charging member comes into contact with the surface of the member to be charged and directly injects the charge into the surface of the member to be charged without a discharge phenomenon, that is, basically without using discharge. Therefore, even if the applied voltage to the contact charging member is equal to or lower than the discharge threshold value, the charged body can be charged to a potential corresponding to the applied voltage.

Since this charging system is not accompanied by generation of active ions such as ozone, no harm is caused by discharge products. However, the contact property of the contact charging member to the member to be charged greatly affects the charging property. Therefore, it is necessary to make the contact charging member more dense, have a large speed difference from the charged body, and contact the charged body more frequently.

The following methods have been proposed as typical contact charging processes.

(A) Roller charging In the contact charging device, a roller charging method using a conductive roller (charging roller) as a contact charging member is preferable from the viewpoint of charging stability and is widely used. The charging mechanism of the roller charging is dominated by the discharge charging system. The charging roller is made of a conductive or medium-resistance rubber material or foam. Further, these are laminated to obtain desired characteristics.

The roller charging method includes a "DC charging method" in which voltage is applied only by DC and an "AC" method in which AC is superimposed.
There is a charging method. The DC charging method is a voltage Vd that is a threshold voltage at which charging is started, that is, a charging start voltage Vth, plus a surface potential Vd of a desired object to be charged (hereinafter referred to as a photoconductor).
In this method, + Vth is applied to perform charging. But D
In the C charging method, since the resistance value of the contact charging member changes due to environmental changes and Vth changes when the film thickness changes due to abrasion of the photoconductor, the potential of the photoconductor can be set to a desired value. It was difficult and the charging could not be made uniform. Therefore, in order to make the charging uniform and improve the charging property, as disclosed in Japanese Patent Laid-Open No. 63-149669, an AC component having a peak-to-peak voltage twice or more Vth is superposed on a DC voltage corresponding to a desired Vd. The "AC charging method" of applying a voltage to the contact charging member was used. It converges to Vd, which is the center of the peak, and is not affected by disturbances such as the environment.

However, in this roller charging method, the essential charging mechanism uses the discharge phenomenon from the contact charging member to the photosensitive member, and even in the "DC charging method", the voltage applied is a value higher than the surface potential of the photosensitive member. Is required and a minute amount of ozone is generated. Further, when the "AC charging method" is used for uniform charging, a larger amount of ozone is generated.
The generation of vibration noise (charging sound) between the contact charging member and the photoconductor due to the electric field of voltage, and the deterioration of the photoconductor surface due to discharge have become remarkable, which has become a new problem.

(B) Fur brush charging For fur brush charging, a member (fur brush charger) having a conductive fiber brush portion is used as a contact charging member.
The conductive fiber brush portion is brought into contact with a photoconductor as a member to be charged, and a predetermined charging bias is applied to charge the surface of the photoconductor to a predetermined polarity and potential. The charging mechanism of this fur brush charging is dominated by the discharge charging system.

As the fur brush charger, a fixed type and a roll type have been put into practical use. A fixed type is made by folding a medium resistance fiber into a base cloth and forming it on a pile and adhering it to an electrode. The roll type is formed by winding the pile around a core metal. As for the fiber density, the contact property is still insufficient for uniform charging, and in order to perform sufficiently uniform charging by injection charging, it is necessary to give the photosensitive member a speed difference such that the mechanical constitution is difficult. Yes, not realistic.

Also in the case of this fur brush charging, in both the fixed type and the roll type, a high charging bias is applied and charging is performed using discharge charging.

(C) Magnetic brush charging For magnetic brush charging, a member (magnetic brush charger) having a magnetic brush portion formed on the brush by magnetically restraining conductive magnetic particles with a magnet roll or the like is used as a contact charging member. The magnetic brush portion is brought into contact with a photoconductor as a member to be charged and a predetermined charging bias is applied to charge the surface of the photoconductor to a predetermined polarity and potential. The charging mechanism in the case of this magnetic brush charging is dominated by the injection charging system.

By using conductive magnetic particles having a particle diameter of 5 to 50 μm as the magnetic brush portion and providing a sufficient speed difference from the photosensitive member, uniform injection charging can be performed. However, there are other adverse effects such as a complicated device configuration, conductive particles forming the magnetic brush portion falling off and adhering to the photoconductor.

(D) Charged Particle-Mediated Charging In the charged particle-mediated charging, a photosensitive member, which is a contact charging member in which charged particles are constrained by an elastic foam roller or the like, forming an nip portion with the photosensitive member is a photosensitive member. Touch the body,
A predetermined charging bias is applied to charge the surface of the photoconductor to a predetermined polarity and potential. The charging mechanism is dominated by the injection charging system. This is because it has advantages such as a simpler device configuration than the magnetic brush charging.

On the other hand, an approach has been taken so that the contact injection charging can be performed from the electrophotographic photosensitive member as well. For example, Japanese Patent Laid-Open No. 6-3921 discloses a trap level or a charge injection layer on the surface of the photosensitive member. A method has been proposed in which charges are injected into a charge holding member such as conductive particles to perform contact injection charging. Since this does not use the discharge phenomenon, the voltage required for charging is only the desired surface potential of the photoconductor, and ozone is not generated. Furthermore, since no AC voltage is applied, no charging noise is generated, and compared to the roller charging method, it is an ozone-less and low-power excellent charging method.

Further, the electrophotographic photosensitive member is, of course,
It is required to have the required sensitivity, electrical properties and optical properties according to the applied electrophotographic process. Particularly, in the case of a photoconductor that is repeatedly used, since an electric or mechanical external force such as charging, image exposure, toner development, transfer to paper and cleaning is directly applied to the surface of the photoconductor, these Durability is required. In particular,
It is required to have durability against abrasion and scratches on the surface of the photoconductor caused by rubbing on the surface of the photoconductor during transfer or cleaning, and deterioration of the photoconductor and potential characteristics due to ozone and charging products generated during charging. Further, there is also a problem that toner adheres to the surface of the photoconductor due to repeated toner development and cleaning, and good cleaning properties are also required.

In order to satisfy the characteristics required for the photoreceptor as described above, attempts have been made to provide a surface protective layer containing a resin as a main component on the photosensitive layer. For example, JP-A-56-
It is proposed in JP-A-42863 and JP-A-53-103741 to improve hardness and wear resistance by providing a surface protective layer containing a curable resin as a main component.

Further, in order to obtain a better image, the surface protective layer of the photoconductor should have not only the characteristics such as high hardness and excellent abrasion resistance but also the resistance of the surface protective layer itself. Required. When the resistance is too low, the electrostatic latent image flows in the surface direction in the surface protective layer, and problems such as image bleeding and blurring occur. However, when the resistance of the surface protective layer is too high, by repeating the electrophotographic process such as charging-exposure, electric charges are accumulated in the surface protective layer, so-called residual potential increases, and the potential is increased during repeated use of the photoconductor. Is not stable, the image quality becomes unstable. To solve this problem, for example, JP-A-57-30843 proposes to control the resistance of the layer by adding a metal oxide as conductive fine particles to the surface protective layer.

Since the surface of the metal oxide has high water absorption and the resistance of the surface protective layer changes depending on the degree of water absorption, the resistance depends on the environment, and only the metal oxide is added as conductive fine particles. Then, it was difficult to suppress the resistance to a proper value in all environments. In order to solve this problem, for example, Japanese Patent Laid-Open No. 62-295066 discloses a surface protection in which a fine metal powder or a fine metal oxide powder having a water repellent treatment and improved dispersibility and moisture resistance is dispersed in a binder resin. It has been proposed to control the resistance of the layer by providing it.

In recent years, environmental problems have been greatly highlighted, and many systems have been proposed that do not generate waste toner than electrophotographic apparatuses. This is usually called a toner recycling process (cleanerless system). For example, in a transfer type electrophotographic apparatus, transfer residual toner remaining on the photoconductor after transfer is removed from the photoconductor surface by a cleaner (cleaning device). Although it is removed to become waste toner, the cleaner is eliminated there, and the toner remaining after transfer on the photoconductor after transfer is removed from the photoconductor by the developing device, and is collected and reused in the developing device. Have been proposed.

This development / cleaning is a fog removal bias for the toner remaining on the photoconductor after transfer at the time of development in the next step and thereafter (fog which is a potential difference between the DC voltage applied to the developing device and the surface potential of the photoconductor). Taking potential difference Vbac
It is a method of collecting by k). According to this method
Since the transfer residual toner is collected by the developing device and reused in the next step and thereafter, it is possible to eliminate the waste toner and reduce the troublesome maintenance. In addition, the so-called cleanerless structure, which does not have an independent cleaning means, has a large space advantage, and the electrophotographic apparatus can be significantly downsized, which is a great advantage in addition to environmental problems.

In the discharge charging system, (1) the applied voltage needs to be higher than the surface potential of the photosensitive member, (2) ozone is generated in a small amount, and (3) the "AC charging method" is used for uniform charging. More ozone is generated,
(4) Vibration noise (charging sound) of the contact charging member and the photoconductor due to the electric field of the AC voltage is generated, and (5) Deterioration of the photoconductor surface due to discharge becomes significant.

On the other hand, when the injection charging system is predominant, these problems are greatly improved, and in particular, charged particle-mediated charging has an advantage that the device structure is simple.

On the other hand, there has been proposed an approach in which contact injection charging can be performed from the electrophotographic photosensitive member, that is, a method of injecting charges into a charge holding member such as conductive particles in the charge injection layer to perform contact injection charging. There is. Since this does not use the discharge phenomenon, the voltage required for charging is only the desired surface potential of the photoconductor, and ozone is not generated. Furthermore, AC
Since no voltage is applied, no charging noise is generated, and compared to the roller charging method, it is an ozone-less and low-power excellent charging method.

Further, in order to improve the charging property, the contact property, that is, the contact area and the contact probability of the charging device (charged particles) and the photosensitive member which is the member to be charged, specifically, the charge injection layer (surface protective layer) is increased. Is effective. Specific methods include reducing the particle size of the charged particles, increasing the distance between the charged particles, in other words, increasing the density, rotating the carrier of the charged particles in the opposite direction to the photoconductor, or rotating the carrier and the photoconductor. There are methods such as making a difference in the peripheral speed of the body.

By combining these, the charging property is improved without the above-mentioned problems while having a simple device configuration. However, these conditions for improving the charging property cause peeling between the photosensitive layer of the photoconductor and the charge injection layer (surface protective layer), resulting in a problem that it cannot withstand repeated use. That is, if the particle size of the charged particles is small, the charging property is improved, but the surface area of the charged particles is increased, the contact area between the charged particles and the photoconductor surface is increased, and the local pressure in the direction perpendicular to the photoconductor surface and / Or due to repeated use for a long period of time due to repeated use, peeling occurs between the photosensitive layer of the photoreceptor and the charge injection layer (surface protective layer),
There is a problem in that a difference in chargeability between the peeled portion and a portion other than the peeled portion, that is, a potential difference is generated, resulting in density unevenness on an image, which makes it impossible to withstand repeated use.

Further, when a charged particle carrier having an elastic surface and carrying charged particles is used, the charging property is improved as compared with the case where it does not have elasticity, but it is still carried on the surface of the photoconductor. Since the contact area between the body or charged particles and the surface of the photoconductor becomes large, and local pressure and / or shear stress in the vertical direction is received for a long time, it becomes easier to peel off after repeated use (= uneven density on the image). There was a problem.

[0035]

SUMMARY OF THE INVENTION It is an object of the present invention to provide the above-mentioned advantages, that is, the voltage required for charging is only the desired surface potential of the photoconductor, without the generation of ozone or the generation of charging noise. An object of the present invention is to provide an electrophotographic photosensitive member that can withstand repeated use and has high durability while maintaining advantages such as low power consumption and a simple device configuration, an electrophotographic apparatus including the electrophotographic photosensitive member, and a process cartridge.

[0036]

According to the present invention, charged particles having conductive particles having a particle size of 10 μm to 10 nm as a main component and a surface having conductivity and elasticity and carrying the charged particles are provided. In an electrophotographic photoreceptor for use in an electrophotographic apparatus, which comprises a particle carrier, the charged particles come into contact with the electrophotographic photoreceptor and directly inject charges into the surface of the photoreceptor to charge the electrophotographic photoreceptor. It has a photosensitive layer containing at least one charge transporting material of the following formula (1), (2) or (3) and a surface protective layer containing conductive particles on a conductive support. An electrophotographic photoreceptor is provided.

[0037]

[Chemical 4]

In the formula, Ar₁And Ar₂Has a substituent
A good alkyl group, an aralkyl group which may have a substituent, or
Represents an aryl group which may have a substituent, and Ar₃Is
Optionally substituted aralkyl or optionally substituted
Represents a good aryl group, Ar _FourHas a hydrogen atom and a substituent
Optionally alkyl group, optionally substituted aralkyl
Shows an aryl group or an aryl group which may have a substituent. Ar
₁, Ar₂, Ar₃And Ar_FourCan be the same or different
Yes.

[0039]

[Chemical 5]

In the formula, Ar ₆ and Ar ₇ represent an aralkyl group which may have a substituent or an aryl group which may have a substituent, and Ar ₅ represents an aryl group which may have a substituent. Show. Ar ₅ , Ar ₆ and Ar ₇ may be the same or different. n is 1 or 2.

[0041]

[Chemical 6]

In the formula, Ar ₈ and Ar ₉ represent an alkyl group which may have a substituent, an aralkyl group which may have a substituent or an aryl group which may have a substituent, and Ar ₁₀ represents Represents an aryl group which may have a substituent, Ar ₁₁ and Ar
₁₂ represents an aralkyl group which may have a substituent or an aryl group which may have a substituent. Ar ₈ , Ar ₉ , Ar ₁₀ , A
r ₁₁ and Ar ₁₂ may be the same or different. Ar ₁₀
And Ar ₈ or Ar ₉ may form a cyclic structure through a single bond or a divalent atomic group. Ar ₁₁ and Ar ₁₂
Similarly, a cyclic structure may be formed through a single bond or a divalent atomic group.

In the present invention, examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group and hexyl group, and examples of the aralkyl group include benzyl group,
Phenethyl group, naphthylmethyl group and furfuryl group and the like, the aryl group, phenyl group, naphthyl group, anthracenyl group and an aromatic hydrocarbon group such as pyrenyl group, pyridyl group, quinolyl group, thienyl group, furyl group, Heterocyclic groups such as a carbazolyl group, a benzimidazolyl group and a benzothiazolyl group can be mentioned.

Examples of the substituent which these groups may have include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group and a hexyl group, a methoxy group,
Examples thereof include alkoxy groups such as ethoxy group and butoxy group, fluorine, chlorine, bromine, halogen atoms such as iodine, aromatic hydrocarbon groups such as phenyl group and naphthyl group, pyridyl group, quinolyl group, Heterocyclic groups such as thienyl group and furyl group, acyl groups such as acetyl group and benzyl group, alkylamino groups such as dimethylamino group, haloalkyl groups such as trifluoromethyl group, cyano group, nitro group. , Phenylcarbamoyl group, carboxyl group, hydroxyl group and the like.

According to the present invention, there are also provided an electrophotographic apparatus and a process cartridge provided with the above electrophotographic photosensitive member.

[0046]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

First, the electrophotographic photosensitive member according to the present invention will be described in detail.

The electrophotographic photosensitive member according to the present invention has at least a photosensitive layer containing a charge transporting material having a specific structure and a conductive surface protective layer on a conductive support.

The support used in the present invention may be any support as long as it has conductivity, and examples thereof include metals and alloys such as aluminum, chromium, nickel, stainless, copper and zinc, and metals such as aluminum and copper. Laminated foil with plastic film, aluminum,
Examples thereof include those obtained by vapor-depositing indium oxide, tin oxide, and the like on a plastic film, or metals, plastic films, and paper on which a conductive layer is formed by coating a conductive substance alone or with an appropriate binder resin.

As the conductive substance used for this conductive layer, metal powder such as aluminum, copper, nickel and silver,
Metal foils and metal fibers, conductive metal oxides such as antimony oxide, indium oxide and tin oxide, polymer conductive materials such as polypyrrole, polyaniline and polymer electrolytes, carbon black, graphite powder and organic or inorganic electrolytes or these Conductive powder whose surface is coated with a conductive substance of

Examples of the shape of the support include a drum shape, a sheet shape and a belt shape, but it is preferable that the shape is any shape most suitable for the applied image forming apparatus.

An undercoat layer may be provided between the support and the photosensitive layer. The undercoat layer functions as a barrier layer or an adhesive layer for controlling charge injection at the interface with the photosensitive layer. The undercoat layer is mainly composed of a binder resin, but may contain the above-mentioned metals or alloys, or their oxides, salts and surfactants.

The binder resin forming the undercoat layer is polyester, polyurethane, polyacrylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, phenol resin, acrylic resin, silicone resin, epoxy resin, urea resin. , Aryl resins, alkyd resins, polyamideimides, polysulfones, polyallyl ethers, polyacetals and butyral resins. The thickness of the undercoat layer is preferably 0.05 to 7 μm, more preferably 0.1 to 2 μm.

The photosensitive layer of the electrophotographic photosensitive member according to the present invention is suitable for at least one charge transporting material selected from the specific hydrazone compounds represented by the above formula (1), (2) or (3). It is basically constructed by combining charge generating materials.

Tables 1 to 3 show typical examples of the compounds represented by the formulas (1) to (3). However, it is not limited to these compounds.

[0056]

[Table 1]

[0057]

[Table 2]

[0058]

[Table 3]

[0059]

[Table 4]

[0060]

[Table 5]

[0061]

[Table 6]

The structure of the photosensitive layer of the electrophotographic photosensitive member in the present invention is a single layer type containing the charge generating material and the charge transporting material in the same layer, or a charge transporting layer containing the charge transporting material and the charge generating material. The charge-generating layer may be a laminated type having a functionally separated layer, but the laminated type is preferable in terms of electrophotographic characteristics. Further, a laminated type photosensitive layer in which a charge transport layer is laminated on the charge generation layer is preferable. This form will be described below.

The charge generation layer in the present invention is formed as a uniform layer in which the charge generation material is formed by a method such as vapor deposition or sputtering, or a dispersion liquid in which the charge generation material is dispersed in a binder resin is applied and dried. It is formed by

Examples of the effective charge generating material used in the present invention include the following materials. These charge generating materials may be used alone or in combination of two or more.

(1) Azo pigments such as monoazo, bisazo and trisazo (2) Indigo pigments such as indigo and thioindigo (3) Phthalocyanine pigments such as metal phthalocyanine and non-metal phthalocyanine (4) Perylene anhydride, perylene acid Perylene pigments such as imides (5) Polycyclic quinone pigments such as anthraquinone and pyrenequinone (6) Squarylium dye (7) Pyrylium salts, Thiopyrylium salts (8) Triphenylmethane dyes (9) Selenium, amorphous silicon Inorganic materials such as

The binder resin can be selected from a wide range of binder resins, for example, polyester resin, butyral resin, polystyrene resin, polyvinyl acetal resin, diallyl phthalate resin, acrylic resin, methacrylic resin, vinyl acetate resin, phenol resin, Examples include silicone resins, polysulfone resins, styrene-butadiene copolymer resins, alkyd resins, epoxy resins, urea resins and vinyl chloride-vinyl acetate copolymer resins.
It is not limited to these. You may use these individually or in mixture of 2 or more types as a homopolymer or a copolymer polymer.

The resin contained in the charge generation layer is preferably 80% by weight or less, and particularly preferably 40% by weight or less.
The thickness of the charge generation layer is preferably 5 μm or less, and particularly preferably a thin film layer having a thickness of 0.01 μm to 2 μm. Further, various sensitizers may be added to the charge generation layer.

The layer containing the charge transporting material, that is, the charge transporting layer has at least the above formula (1), as described above.
It can be formed by combining the charge transport material of the specific hydrazone compound represented by (2) or (3) and a suitable binder resin. Examples of the binder resin used in the charge transport layer include those used in the charge generation layer, and further include photoconductive polymers such as polyvinylcarbazole and polyvinylanthracene.

As the charge transport material, the above formula (1),
At least one of the specific hydrazone-based compounds represented by (2) or (3) may be used alone or in combination of two or more, and a charge transport material having another structure [for example, pyrene and Polycyclic aromatic compounds such as anthracene, carbazole, indole, oxazole,
Heterocyclic compounds such as thiazole-based, oxadiazole-based, pyrazole-based, pyrazoline-based, thiadiazole-based and triazole-based compounds, triarylmethane-based compounds, or polymers having groups of these compounds in the main chain or side chain (for example, , Poly-N-vinylcarbazole, polyvinylanthracene, etc.)] and the like.

The mixing ratio of the binder resin and the charge transport material is
10-50 parts of charge transport material per 100 parts by mass of binder resin
It is preferably 0 part by mass. The charge transport layer is electrically connected to the above-mentioned charge generation layer and has a function of receiving charge carriers injected from the charge generation layer in the presence of an electric field and transporting these charge carriers to the surface. ing. Since the charge transport layer has a limit to transport charge carriers, the film thickness cannot be increased more than necessary, but it is preferably 5 μm to 40 μm, and particularly preferably 10 μm to 30 μm.

Further, additives such as an antioxidant, an ultraviolet absorber and a plasticizer may be added to the charge transport layer as needed.

In forming such a charge transport layer, a suitable organic solvent is used and a coating method such as a dip coating method, a spray coating method, a spinner coating method, a roller coating method, a Mayer bar coating method and a blade coating method. Can be done using.

Next, the photosensitive layer in the single-layer type electrophotographic photosensitive member will be described. The single-layer type photosensitive layer is formed by applying and drying a liquid in which a charge generating material and a charge transporting material are dissolved and dispersed in the resin. The thickness of the single-layer type photosensitive layer is preferably 5 to 40 μm, particularly 10 to 30 μm.
Is preferred.

As the binder resin for the surface protective layer used in the present invention, a curable resin is more preferable because it has a high surface hardness and excellent abrasion resistance. Examples of curable resins include, but are not limited to, acrylic resins, urethane resins, epoxy resins, and silicone resins.

In the present invention, examples of the conductive particles used in the surface protective layer include metals, metal oxides and carbon black, with metals and metal oxides being preferred.
Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver, stainless steel, and the like, or those obtained by vapor-depositing these metals on the surface of plastic particles. As the metal oxide, zinc oxide, titanium oxide, tin oxide,
Examples thereof include antimony oxide, indium oxide, bismuth oxide, indium oxide doped with tin, tin oxide doped with antimony or tantalum, and zirconium oxide doped with antimony. These may be used alone or in combination of two or more. When two or more kinds are used in combination, they may be simply mixed, or may be in the form of solid solution or fusion.

The content of the conductive particles is preferably 5 to 90% by mass based on the total mass of the surface protective layer. If it is less than 5% by mass, the resistance value of the surface protective layer may be too high, and if it is more than 90% by mass, the resistance of the surface layer of the photoconductor tends to be low, which may cause deterioration of charging ability and pinholes. .

Further, in the present invention, it is particularly preferable to use a metal oxide among the above-mentioned conductive particles in terms of transparency.

Further, from the viewpoint of reducing the water absorption of the conductive particles and suppressing the environmental fluctuation of the resistance of the surface protective layer, it is preferable to subject the surface of the metal or metal oxide to a water repellent treatment. Examples of the treatment agent used for the water repellent treatment include compounds such as titanate coupling agents, fluorine-containing silane coupling agents, fluorine-modified silicone oils, fluorine-based surfactants, and acetoalkoxyaluminum diisopropylate.

When the conductive particles are dispersed in the surface protective layer,
In order to prevent scattering of incident light by dispersed particles, it is preferable that the particle system is smaller than the wavelength of incident light, and generally, the number average particle diameter is preferably 0.3 μm or less.

In the cleaning process for removing the residual toner, the most common blade cleaning method is always accompanied by the problem of blade reversal. This is a problem that occurs because the frictional force between the surface of the photoreceptor and the blade is very high, and blade reversal occurs when a certain threshold is exceeded. Therefore, in the surface protective layer of the present invention, it is preferable to add a lubricant such as fluorine atom-containing resin particles to the surface protective layer in order to reduce the frictional force on the surface of the photoreceptor.

As the lubricating particles, fluorine atom-containing resin particles, silicon particles, alumina particles and silicone particles are preferable, and among them, fluorine atom-containing resin particles are preferable. Fluorine atom-containing resin particles and silicone particles are
Due to the low surface energy and the cleavage of the particles themselves, slippage occurs, and in the case of silicon particles and alumina particles, the slippage effect by the particles themselves does not occur, but by dispersing these particles in the film, it becomes There is an effect that unevenness is generated, and as a result, the frictional force with the contacting object is reduced.

Examples of the fluorine atom-containing resin include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polydichlorodifluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene. Examples of the resin include one or two or more selected from the group consisting of a copolymer, a tetrafluoroethylene-ethylene copolymer and a tetilafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer. .
It is also possible to use commercially available fluorine atom-containing resin fine particles as they are. The molecular weight is preferably 3,000 to 5,000,000. The particle size is preferably 0.01 to 10 μm, and particularly preferably 0.05 to 2.0 μm.

Further, in the present invention, various coupling agents and antioxidants may be added to the surface protective layer in order to further improve dispersibility, adhesiveness, environment resistance and the like. The film thickness of the surface protective layer in the present invention is preferably 0.1 to 10 μm, and particularly preferably 2 to 7 μm.

The above surface protective layer can be formed by vapor deposition or coating. In particular, the coating method is preferable because it is possible to form films having various compositions over a wide range from thin films to thick films. Examples of the coating method include a dip coating method, a spray coating method, a beam coating method, a bar coating method, a blade coating method and a roller coating method.

The problem of the present invention is solved by using the above electrophotographic photosensitive member. That is, the particle size is 10 μm
Charged particles having conductive particles of 10 nm as a main component,
It is composed of a charged particle carrier that has a surface having conductivity and elasticity and carries the charged particles, and the charged particles come into contact with the electrophotographic photosensitive member and directly charge the surface of the photosensitive member to be charged. Since the electrophotographic photosensitive member used in the electrophotographic device has a photosensitive layer containing a charge transporting material of a hydrazone compound having at least a specific structure and a conductive surface protective layer on a conductive support, it is necessary for charging. The voltage to be applied is only the desired surface potential of the photoconductor, no ozone is generated, no charging noise is generated, the power consumption is low, and the device configuration is simple. No peeling occurs between the photosensitive layer and the charge injection layer (surface protective layer), and the problem of density unevenness on the image due to the difference in chargeability between the peeled portion and the other portion, that is, the potential difference does not occur. High durability It made.

More specifically, if the particle size of the charged particles is small, the charging property is improved, but since the surface area of the charged particles is large, the contact area between the charged particles and the surface of the photosensitive layer is large and the surface of the photosensitive member is By receiving local pressure and / or shear stress in the vertical direction repeatedly for a long time,
Peeling occurs between the photosensitive layer of the photoconductor and the charge injection layer (surface protection layer), causing a difference in chargeability between the peeled portion and a portion other than that, that is, a potential difference, which appears as uneven density on the image. The problem of being unable to withstand repeated use can be solved. In addition, when a charged particle carrier having an elastic surface and carrying charged particles is used, the charging property is improved as compared with the case where the charged particle carrier is not elastic, but the carrier or the charge is still applied to the surface of the photoreceptor. Since the contact area between the particles and the surface of the photoconductor becomes large and the local pressure and / or shear stress in the vertical direction is received for a long time, peeling is more likely to occur with repeated use (= density unevenness on the image). Solvable.

The reason why the peeling does not occur is considered to be a high degree of adhesion between the photosensitive layer and the charge injection layer (surface protective layer), and it is considered that this is particularly due to the structure of the charge transport material contained in the photosensitive layer. To be That is, it has a hydrazone skeleton at the center, and at one end (C atom side) of the three types of formula (1),
In addition to having the structures shown in (2) and (3), the structure in which the alkyl group is not alone bonded to the other end (N atom side) has an effect, and adhesion is obtained. It is considered that injection chargeability is maintained, image density unevenness does not occur, and high durability and long life are achieved. It is expected that the latter will be particularly important.

A specific example of an electrophotographic apparatus using the electrophotographic photosensitive member of the present invention is shown in FIG. In this electrophotographic apparatus, a primary charging member 2, an exposure unit 5, a developing unit 6, and a transfer unit 7 are arranged on the peripheral surface of an electrophotographic photosensitive member 1.

In the image forming method, first, a voltage is applied to the primary charging member 2 to charge the surface of the photoconductor 1 and the exposing means 5 is used.
To expose the image corresponding to the original on the surface of the photoconductor 1,
Form an electrostatic latent image. Next, the toner in the developing device 6 is attached to the photoconductor 1 to develop (visible) the electrostatic latent image on the photoconductor 1. Furthermore, the toner image formed on the photoconductor 1 is transferred onto the transfer material P such as paper supplied by the transfer means 7, and the residual toner remaining on the photoconductor 1 without being transferred to the transfer material is cleaned by a cleaner or the like. To collect. In recent years, cleanerless systems have also been studied, and residual toner can be directly collected by a developing device. Further, after the static elimination processing is performed by the pre-exposure from the pre-exposure means, it is repeatedly used for image formation. The pre-exposure means is not always necessary.

In the electrophotographic apparatus shown in FIG. 1, the light source of the exposing means 5 is halogen light, fluorescent light, laser light or L light.
ED or the like can be used. Also, other auxiliary processes may be added if necessary.

In the present invention, among the above-mentioned photoconductor 1, primary charging means 2, developing means 6 and cleaning means, a plurality of components are integrally combined as a process cartridge, and this process cartridge is constructed. It may be detachably attached to the main body of an electrophotographic apparatus such as a copying machine or a printer. For example, at least one of the primary charging unit 2, the developing unit 6, and the cleaning unit is integrally supported together with the photosensitive member 1 to form a cartridge, and the process cartridge is detachably attached to the apparatus body by using the guide means such as the rail 10 of the apparatus body. It can be 9. Further, when the electrophotographic apparatus is a copying machine or a printer, the exposure light L uses reflected light or transmitted light from the original. Alternatively, it is light emitted from a signalized document by scanning a laser beam, driving an LED array, driving a liquid crystal shutter array, or the like performed according to the signal.

The charging device of the present invention shown in FIG. 2 comprises a conductive elastic roller 2 (hereinafter referred to as a charging roller) and conductive particles 3 (hereinafter referred to as a charged particle) mainly for promoting charging. It is composed of a regulating member 4 which is a charged particle supplying means. The photoconductor 1 is charged with the charged particles 3 applied to the contact nip between the charging roller and the electrophotographic photoconductor 1. As a result, the charging roller 2 can come into contact with the electrophotographic photosensitive member 1 with a speed difference, and at the same time, the charge can be directly injected into the photosensitive member 1 densely via the charged particles 3. Therefore, in the present invention, a high charging efficiency, which has not been obtained by the conventional roller charging, can be obtained, and a potential substantially equal to the potential applied to the charging member can be applied to the photoconductor. Therefore, the bias required for charging is sufficient to be a voltage corresponding to the potential required for the photoconductor, and a safe charging system that does not use the discharge phenomenon is realized.

Next, the main constituent members of the charger used in the present invention will be described.

<Charging Roller> The charging roller 2 is manufactured by forming a medium resistance layer 2b of rubber or foam on the cored bar 2a. The medium resistance layer 2b includes a resin (for example, urethane), conductive particles (for example, carbon black),
Formulated with a sulfiding agent, a foaming agent, etc., it was formed into a roller shape on the cored bar 2a. After that, the surface was polished as needed to prepare an elastic conductive roller 2 having a diameter of 12 mm and a longitudinal length of 250 mm. When the roller resistance of this example was measured, it was 100 kΩ. Total pressure 1 on the core of roller 2
100 V was applied to the core metal 2a and the aluminum drum in a state of being pressure-bonded to an aluminum drum having a diameter of 30 mm so as to apply a load of kg, and measurement was performed. Here, the elastic roller 2
Is important to function as an electrode. That is, it is necessary to have elasticity to obtain a sufficient contact state, and at the same time, to have a sufficiently low resistance to charge the moving photoconductor. On the other hand, it is necessary to prevent voltage leakage when a defective portion such as a pinhole exists on the photoconductor. When an organic photoconductor is used as the electrophotographic photoconductor, a resistance of 10 ⁴ to 10 ⁷ Ω is preferable in order to obtain sufficient chargeability and leak resistance.

If the hardness of the charging roller is too low, the shape of the charging roller will not be stable and the contactability will be poor. The Asker C hardness is preferably in the range of 25 degrees to 50 degrees.

The material of the charging roller is not limited to the elastic foam, but the material of the elastic body is EPD.
Examples thereof include M, urethane, NBR, silicone rubber, a rubber agent in which a conductive substance such as carbon black or a metal oxide is dispersed in IR or the like for resistance adjustment, or a material obtained by foaming these. In addition, especially without dispersing a conductive substance,
It is also possible to adjust the resistance by using an ion conductive material.

The charging member is not limited to the charging roller, and an elastic body such as a fur brush in which each pile has elasticity can be used. Here, the fur brush roller has a resistance-adjusted fiber (Rec made by Unitika) planted at a density of 155 fibers / mm ² and a fiber length of 3 mm to form a pile, after which the pile is wound and fixed on a core metal of φ6 mm, It is formed into a roller shape.

<Charged particles> In this embodiment, the specific resistance is 10
Conductive zinc oxide particles 3 having an average particle diameter of ⁶ μm · 3 μm were used. As the material for the particles, various conductive particles such as conductive inorganic particles such as other metal oxides and a mixture with an organic substance can be used. Here, the particle resistance is preferably 10 ¹⁰ Ω · cm or less in order to transfer charges through the particles. Here, the resistance was measured by the tablet method and normalized. A powder sample of about 0.5 g was placed in a cylinder with a bottom area of 2.26 cm ² , 15 kg of pressure was applied to the upper and lower electrodes, a voltage of 100 V was applied at the same time, and the resistance value was measured. Was calculated. The particle size is preferably 50 μm or less in order to obtain good charging uniformity. The lower limit of the particle size is 10 assuming that the particles can be stably obtained.
nm is the limit. In the present invention, the particle size when the particles are formed as an aggregate is defined as the average particle size of the aggregate. To measure the particle size, 100 or more are extracted from observation with an optical or electron microscope, and the volume particle size distribution is calculated with the maximum chord length in the horizontal direction, and 50% of that is calculated.
It was determined by the average particle size.

The method for measuring the charge amount of the charged particles in the present invention will be described below with reference to FIG. 23 ° C / 60% relative humidity
% Environment, iron powder carrier DSP-138, 19.6 g
Then, a mixture of 0.4 g of the conductive particles and 0.4 g of the conductive particles is placed in a polyethylene bottle having a volume of 50 to 100 ml and shaken by hand 50 times. Next, 1.0 to 1.2 g of the mixture is put into a metal measuring container 92 having a 500 mesh screen 93 on the bottom,
The metallic lid 94 is used. At this time, the total mass of the measurement container 92 is weighed and set as W1 (g). Next, in the suction device 91 (at least the portion in contact with the measurement container 92 is an insulator),
Suction is performed from the suction port 97 and the air flow rate control valve 96 is adjusted to set the pressure of the vacuum gauge 95 to 4900 hPa. In this state, suction is performed for 1 minute to remove the toner by suction. Electrometer 99 at this time
Is set to V (volt). Here, 98 is a capacitor, and the capacitance is C (μF). In addition, the mass of the entire measurement container after suction is weighed and is W2 (g). The triboelectric charge amount (μC / g) of this toner is calculated by the following mathematical formula (1).

[0100]     Triboelectric charge amount (μC / g) = CV / (W1-W2) (1)

The triboelectric charge amount of the electrically conductive particles for charging used in the present invention with respect to the iron powder carrier was +5 μC / g.

If the contact frequency between the charging member and the electrophotographic photosensitive member is high, the charge can be injected more efficiently. That is, the particle size and density of the charged particles, the elasticity of the carrier that carries the charged particles, and the like influence. Alternatively, the charging member has a speed difference with respect to the surface of the body to be charged, that is, the surface of the electrophotographic photosensitive member, so that the charges can be injected with higher efficiency. The charging member and the electrophotographic photosensitive member are preferably rotated in opposite directions, that is, counter rotated. That is, a good condition for these charging means is that damage to the electrophotographic photosensitive member becomes large, which causes a film shift or peeling between the photosensitive layer and the surface protective layer. If deviation or peeling occurs, the chargeability deteriorates, resulting in image defects such as unevenness on the image.

[0103]

EXAMPLES The present invention will be described in more detail with reference to specific examples. In addition, "part" in an Example shows a mass part.

(Example 1) 50 parts of titanium oxide powder coated with tin oxide containing 10% antimony oxide, 25 parts of resol type phenol resin, 30 parts of methyl cellosolve,
30 parts of methanol and 0.002 parts of silicone oil (polydimethylsiloxane polyoxyalkylene copolymer, weight average molecular weight 3000) were dispersed for 2 hours in a sand mill using 1 mmφ glass beads to prepare a coating material for a conductive layer. This coating material was applied onto a 30 mmφ aluminum cylinder by dip coating and dried at 140 ° C. for 30 minutes to form a conductive layer having a film thickness of 20 μm.

Then, a solution prepared by dissolving 5 parts of 6-66-610-12 four-element polyamide copolymer in a mixed solvent of 70 parts of methanol / 25 parts of butanol was applied onto the conductive layer by dip coating and dried. An undercoat layer having a film thickness of 1 μm was formed.

Next, using 10 parts of oxytitanium phthalocyanine as a charge generating material, polyvinyl butyral (trade name: S-REC BX-1, manufactured by Sekisui Chemical Co., Ltd.)
A solution obtained by dissolving 10 parts in 400 parts of cyclohexanone was dispersed for 5 hours in a sand mill using 400 parts of 1 mmφ glass beads, and then 400 parts of ethyl acetate was added to prepare a coating solution for the charge generation layer. This coating solution was applied onto the undercoat layer by dip coating and dried at 80 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm.

Next, as a charge transporting material, the hydrazone compound example No. 3 shown in Table 3 was used. 10 parts of 26, 10 parts of polycarbonate (trade name: Iupilon Z-200, manufactured by Mitsubishi Gas Chemical Co., Inc.) and 20 parts of dichloromethane /
It was dissolved in a mixed solvent of 50 parts of monochlorobenzene, this solution was applied onto the charge generation layer by dip coating, and dried at 110 ° C. for 60 minutes to form a charge transport layer having a thickness of 18 μm.

Next, a surface layer was formed on this photosensitive layer.
First, 30 parts of an acrylic monomer of the following formula (4),

[0109]

[Chemical 7] Antimony-doped tin oxide ultrafine particles (average particle size 0.02 μm) 60 surface-treated with a silane compound of the following formula (5) 60
Department

[0110]

[Chemical 8] And 200 parts of ethanol are mixed and the mixture is mixed with a sand mill device.
After being dispersed for 0 hours, 8 parts of 2-methylthioxanthone as a photopolymerization initiator was further added and mixed to obtain a preparation liquid for the surface layer. Next, this solution is applied onto the photosensitive layer by a dip coating method,
After drying, the film thickness was 3.5 μm by irradiating with ultraviolet light with a high pressure mercury lamp at a light intensity of 800 mW / cm ² for 30 seconds.
A surface layer of m was formed to prepare an electrophotographic photoreceptor. Further, the dispersibility of the surface layer preparation liquid was good, and the surface of the prepared surface layer film was a uniform and even surface.

The produced electrophotographic photosensitive member was set at 23.5 ° C./5.
After being left overnight in an environment of 5% RH, evaluation was performed using a laser printer (trade name: LBP-SX, a modified machine manufactured by Canon Inc.). The laser printer was remodeled as an electrophotographic apparatus using the charged particle interposition charging means shown in FIG. 1, and the process cartridge of FIG. 1 was rebuilt so that it could be incorporated into the laser printer. The specific conditions of each device were as follows.

The charging roller was produced by forming a medium resistance layer of rubber on a cored bar. The medium resistance layer is formulated with urethane resin, conductive particles (carbon black), a sulfiding agent, a foaming agent, etc., and is molded into a roller shape on a cored bar, and then the surface is polished to a diameter of 12 mm and a longitudinal length of 250.
mm elastic conductive roller was prepared. When the resistance of this roller was measured, it was 100 kΩ. The measurement was performed by applying 100 V to the core metal and the conductive support in a state where the core metal of the roller was pressure-bonded to the electrophotographic photosensitive member so that a total pressure of 1 kg was applied.

In this embodiment, as the electroconductive particles (charged particles) for the electrophotographic photosensitive member and the charging roller to be injected and charged through the electroconductive particles, the specific resistance is 10 ⁶ Ω · cm and the average particle size is 3 μm. The conductive zinc oxide particles of Here, the resistance was measured by the tablet method and normalized. A 0.5 g powder sample was placed in a cylinder with a bottom area of 2.26 cm ² , 15 kg of pressure was applied to the upper and lower electrodes, a voltage of 100 V was applied at the same time, the resistance value was measured, and then normalized to determine the specific resistance. It was calculated.

Further, in order to uniformly supply the charged particles to the contact nip between the roller and the photosensitive member, a charged particle coating means is provided. As a supply means, a regulating blade is brought into contact with the electrophotographic photosensitive member, and charged particles are held between the photosensitive member and the regulating blade. Then, as the electrophotographic photosensitive member rotates, a fixed amount of charged particles are applied to the charging roller.

In this embodiment, the charging roller is rotated with a speed difference with respect to the electrophotographic photosensitive member. The electrophotographic photosensitive member has a drum shape with a diameter of 30 mm and a peripheral speed of about 50.
It rotates at a constant speed of mm / sec. First, charged particles are applied to the surface of the photoconductor by a regulating blade. After that, it reaches the charging roller portion. The charging roller was driven at about 80 rpm so that the roller surface moved in the opposite direction to the photoreceptor at a constant speed, and a DC voltage of -700 V was applied to the roller core metal. This allows
The surface of the photoconductor is charged to a potential equal to the applied voltage. In this embodiment, the charging is carried out by injecting charging by the charging accelerating particles existing in the contact nip between the roller and the body to be charged rub the surface of the body to be charged without a gap. Further, as the cleaning means for the transfer residual toner, a simultaneous development cleaning means (toner recycling process) for collecting with a developing device was used.

The electrophotographic photosensitive member was evaluated at 23.5 ° C./5.
5% RH, 23.5 ° C / 5% RH and 30 ° C / 78% R
In the H environment, the light potential at the initial stage of durability adjustment was adjusted to -150 V by the exposure amount, and 20,000 A4 size prints were durable in each environment, and evaluated by image evaluation and peeling of the surface protective layer. did. The results are shown in Table 4. In the table, ◯, ◯ Δ and Δ indicate peeling and image rank, with ◯ being the best and ◯ Δ and Δ being bad in this order.

Comparative Examples 1 to 4 As the charge transport material, the hydrazone compound example No. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that Comparative CTM1, Comparative CTM2 and Comparative CTM3 represented by the following formulas were used instead of 26, and the same evaluation was performed. The results are shown in Table 4.

[0118]

[Chemical 9]

(Examples 2 to 5) As the charge transport material, the hydrazone compounds shown in Table 3, No. 26 in place of the hydrazone-based compound example No. 6, hydrazone compound example No. 6 in Table 3. 18, No. 19 and No. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that No. 11 was used, and the same evaluation was performed. The results are shown in Table 4.

(Examples 6 to 9) In Example 1, the electrophotographic apparatus was replaced with the injection charging method and the toner recycling process (cleanerless system) as shown in FIG. ． 26 instead of the hydrazone-based compound example No. 1, hydrazone compound example Nos. 17, No. 20 and the hydrazone compound example Nos. Example 1 was repeated except that 10 was used.

The points different from the electrophotographic apparatus of Embodiment 1 will be described below.

(1) Overall Structure of Electrophotographic Apparatus The charging device is not equipped with a charged conductive particle feeder. The conductive particles are added to the developer, accumulated, and supplied to the charging roller via the photosensitive drum together with the development of the toner.

Reference numeral 60 is a developing device. Rotating photosensitive drum 1
The electrostatic latent image on the surface is developed as a toner image by the developing device 60 at the developing portion a. In the developing device 60, a mixture tm in which conductive particles m are added to the developer t is provided.

The electrophotographic apparatus of the present embodiment is a toner recycling process, and the transfer residual toner remaining on the surface of the photosensitive drum 1 after the image transfer is not removed by a dedicated cleaner (cleaning device), and the residual toner of the photosensitive drum 1 is removed. As the toner is temporarily collected by the charging roller that rotates counter with rotation and is rotated around the outer circumference of the roller, the inverted toner charges are normalized and sequentially discharged to the photosensitive drum to reach the developing portion a. Are collected and reused.

(2) Charging roller The constitution is similar to that of the first embodiment except that the charging conductive particle feeder is not provided.

(3) Developing Device The developing device 60 of this embodiment is a reversal developing device using a one-component magnetic toner (negative toner) as the developer t. In the developing device, a mixture tm of a developer (toner) t and conductive particles m is provided.

Reference numeral 60a denotes a non-magnetic rotary developing sleeve as a developer carrying / conveying member which encloses a magnet roll 60b, and the pre-development mixture t provided in the developing container 60e.
The toner t in m is subjected to the layer thickness regulation and the charge application by the regulation blade 60c in the process of being conveyed on the rotary developing sleeve 60a. Reference numeral 60d is a stirring member that circulates the toner in the container and sequentially conveys the toner to the periphery of the sleeve.

The toner t coated on the rotary developing sleeve 60a is rotated by the rotation of the sleeve 60a, so that the developing portion (developing area portion) is a facing portion between the photosensitive drum 1 and the sleeve 60a.
It is transported to a. A developing bias voltage is applied to the sleeve 60a from a developing bias applying power source S5.

In this embodiment, the developing bias voltage is D
The superimposed voltage of the C voltage and the AC voltage was used. As a result, the electrostatic latent image on the photosensitive drum 1 side is reversely developed by the toner t.

(3) -a The one-component magnetic toner t, which is a toner developer, is prepared by mixing a binder resin, magnetic particles and a charge control agent, and kneading, pulverizing and classifying the toner, and further producing conductive particles. It is produced by adding m and a fluidizing agent as an external additive. The average particle diameter (D4) of the toner was 7 μm.

(3) -b Conductive particles m: In accordance with Example 1.

(4) Amount of Conductive Particles Carried, Coverage Since the toner recycling structure is used in this embodiment, a larger amount of toner contaminates the surface of the charging roller as compared with the embodiment 1. The toner has a resistance value of 10 ¹³ Ω · cm or more in order to maintain electric charges due to frictional charging on the surface. Therefore, when the roller is contaminated with the toner, the resistance of particles carried on the roller is increased and the charging performance is deteriorated. Even if the resistance of the charged conductive particles is low, the resistance of the powder carried by the mixing of the toner rises, and the chargeability is impaired. Therefore, the carrying amount is
Preferably 0.1-100 mg / cm ² equivalent in the form of, particularly preferably 0.1 to 10 mg / cm ^2. However, if that component contains a large amount of toner, the charging performance naturally lowers. In this case, the resistance of the supported particles increases, and the situation can be grasped. That is, in actual use, the resistance of the particles carried on the charging roller (including contaminants such as toner and paper powder) is measured by the above-mentioned method, and the value is 10 ⁻¹ to 10 ¹² Ω · cm.
Is preferable, and particularly 10 ⁻¹ to 10 ¹⁰ Ω · cm
Is preferred.

Further, in order to grasp the effective amount of charged conductive particles in charging, it is more important to adjust the coverage of the conductive particles. Since the charged conductive particles are white, they can be distinguished from the magnetic toner black. The area showing white in observation with a microscope is obtained as an area ratio. When the coverage is 0.1 or less, the charging performance is insufficient even if the peripheral speed of the charging roller is increased. Therefore, it is preferable to keep the coverage of the charged conductive particles within the range of 0.2 to 1.

The amount of carried particles was adjusted basically by adjusting the amount of charged conductive particles added to the developer. Also,
If necessary, adjustment was performed by bringing an elastic blade into contact with a part of the outer circumference of the charging roller. By abutting the members, there is an effect of normalizing the triboelectrification polarity of the toner, and it becomes possible to adjust the amount of particles carried on the rollers.

Comparative Examples 4 and 5 As the charge transport material,
Compound example No. An electrophotographic photosensitive member was produced in the same manner as in Example 6 except that Comparative CTM4 and Comparative CTM5 represented by the following formulas were used instead of 26, and the same evaluation was performed. The results are shown in Table 4.

[0136]

[Chemical 10]

[0137]

[Table 7]

[0138]

As described above, according to the present invention,
The charged particles are mainly composed of conductive particles having a particle size of 10 μm to 10 nm, and a charged particle carrier that carries the charged particles and has a surface having conductivity and elasticity, and the charged particles are electrophotographic. An electrophotographic photosensitive member used in an electrophotographic apparatus which is in contact with a photosensitive member and injects electric charges directly into the surface of the photosensitive member so that the electrophotographic photosensitive member contains at least a charge transporting material of a hydrazone compound having a specific structure and a conductive surface. By having a protective layer, the chargeability is good and the voltage required for charging is only the surface potential of the desired photoconductor, ozone is not generated and charging noise is not generated, and the device configuration is low power and simple. Even after repeated use, peeling does not occur between the photosensitive layer and the charge injection layer (surface protective layer) due to local pressure and / or shear stress in the direction perpendicular to the surface of the photoreceptor from the charging member, and peeling occurs. Chargeability drop due without image defects such as uneven image density caused an electrophotographic photosensitive member is highly durable, it has become possible to provide an electrophotographic apparatus and a process cartridge.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an electrophotographic apparatus including a process cartridge having an electrophotographic photosensitive member of the present invention.

FIG. 2 is a diagram showing in detail conductive particle supply means of the electrophotographic apparatus of FIG.

FIG. 3 is a diagram showing a schematic configuration of another electrophotographic apparatus of the present invention.

FIG. 4 is a diagram showing a schematic configuration of an apparatus for measuring a triboelectric charge amount of toner particles.

[Explanation of symbols]

1 Electrophotographic photoreceptor (image bearing body, charged body) 2 Charging roller (contact charging member) 2a core metal 2b flexible member 3 charged particles 4 Control blade (charged particle supply means) 5 Exposure equipment 6 Development device 6a Magnet roller 6b Development sleeve 7 Transfer roller 8 fixing device 9 Process cartridge 10 Guide member a Development area b Transfer nip n Charging nip

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 5/147 502 G03G 5/147 502 503 503 504 504 504 15/02 101 15/02 101 15/08 507 15 / 08 507B (72) Inventor Shinji Takagi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroshi Saito 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F Terms (Reference) 2H068 AA03 AA05 AA06 AA20 AA21 AA37 BA22 BA23 BA24 BA25 BB31 BB33 BB57 CA00 CA05 CA33 FA01 FA27 FC01 2H077 AA37 AC16 AD06 AD13 AD16 AD31 AD36 EA11 GA03 GA04 GA17 2H200 FA02 FA07 GA25 GA34 GA23 GA34 GA23 GA34 GA23 GA34 GB37 HA02 HA21 HA28 HB12 HB17 HB22 HB45 HB46 HB47 JA02 JB10 LA23 LA38 MA02 MA08 MA14 MB05 MB06 MC02 MC06 MC15

Claims (52)

[Claims] 1. Conductive particles having a particle size of 10 μm to 10 nm
Charged particles mainly composed of a child and a surface having conductivity and elasticity
A charged particle carrier that has a surface and carries the charged particles.
The charged particles contact the electrophotographic photoreceptor,
For an electrophotographic device that injects electric charges directly onto the surface of an optical body to charge it
In the electrophotographic photoreceptor to be used, the electrophotographic photoreceptor is
At least the following formulas (1), (2) or on the electrically conductive support:
A photosensitive layer containing a charge transport material of one of (3) and
And having a surface protective layer containing conductive particles
And an electrophotographic photoreceptor. [Chemical 1] (In the formula, Ar₁And Ar₂Is an optionally substituted alkyl group
Group, an aralkyl group which may have a substituent or a substituent
Represents an aryl group which may have, Ar₃Has a substituent
An optionally substituted aralkyl group or an optionally substituted aryl
Represents a group, Ar _FourMay have a hydrogen atom or a substituent
Alkyl group, aralkyl group which may have a substituent, or
The aryl group which may have a substituent is shown. Ar₁, Ar₂,
Ar₃And Ar_FourMay be the same or different) [Chemical 2] (In the formula, Ar₆And Ar₇Is an aral which may have a substituent
A kill group or an aryl group which may have a substituent is shown.
r_FiveRepresents an aryl group which may have a substituent. Ar_Five,
Ar₆And Ar₇May be the same or different. n is 1
Or 2) [Chemical 3] (In the formula, Ar₈And Ar₉Is an optionally substituted alkyl group
Group, an aralkyl group which may have a substituent or a substituent
Represents an aryl group which may have, Ar_TenHas a substituent
Represents an optionally substituted aryl group, Ar₁₁And Ar₁₂Is a substituent
May have an aralkyl group or may have a substituent
Indicates an aryl group. Ar₈, Ar₉, Ar_Ten, Ar₁₁as well as
Ar₁₂May be the same or different. Ar_TenAnd Ar₈
Or Ar₉Is a single bond or a divalent atomic group
You may form the cyclic structure. Ar₁₁And Ar₁₂As well
Forms a cyclic structure through a single bond or divalent atomic group
You may have) 2. Particles carried on the charged particle carrier
Resistance is 10¹²-10 ^-1Ω · cm, and the supported amount of the particles
Is 0.1 mg / cm²~ 50 mg / cm²Is an electronic photograph
The electrophotographic photosensitive member according to claim 1, which is used in an apparatus. 3. When the ratio of the conductive particles coating the charged particle carrier is defined as the coverage Rc, 0.2 ≦ Rc ≦
The electrophotographic photosensitive member according to claim 1 or 2, which is used in the electrophotographic apparatus of item 1. 4. The surface roughness Ra of the charged particle carrier is 1
～500Myuemu, electrophotographic photosensitive member according to claim 1, the surface resistance is used in an electrophotographic apparatus which is ^{10 4} ~10 10 Ω · cm. 5. The electrophotographic photosensitive member according to claim 1, wherein the charged particle carrying member is used in an electrophotographic apparatus which is an elastic member having a porous surface. 6. An electrophotographic apparatus comprising: charged particles having a resistance of 10 ¹² to 10 ⁻¹ Ω · cm, and a charged particle supply means for supplying the particles to the surface of the charged particle carrier. 5. The electrophotographic photosensitive member according to any one of 5 above. 7. The charged particle supplying means stores the charged particles together with a developer in a developing means, transfers the charged particles onto the photosensitive member, and transfers the charged particles to a recording medium without partially transferring the charged particles. The electrophotographic photosensitive member according to claim 6, which is used in an electrophotographic apparatus which remains on the photosensitive member and is supplied to a charging unit. 8. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer is a layer in which a charge generation layer and a charge transport layer are laminated in this order. 9. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer is a layer containing a charge generating material and a charge transporting material. 10. The electrophotographic photoreceptor according to claim 1, wherein the binder resin used in the surface protective layer is a curable resin. 11. The electrophotographic photosensitive member according to claim 1, wherein the conductive particles are a metal or a metal oxide. 12. The electrophotographic photosensitive member according to claim 1, wherein the conductive particles are subjected to a water repellent treatment. 13. The electrophotographic photosensitive member according to claim 1, wherein the surface protective layer contains lubricating particles. 14. The electrophotographic photosensitive member according to claim 13, wherein the lubricating particles are at least one of fluorine atom-containing resin particles, silicon particles, alumina particles and silicone particles. 15. A charged particle carrier having a conductive particle having a particle size of 10 μm to 10 nm as a main component and a surface having conductivity and elasticity, the charged particle carrying member carrying the charged particle, In the electrophotographic apparatus in which the charged particles come into contact with the electrophotographic photosensitive member and directly inject charges to the surface of the electrophotographic photosensitive member to charge the electrophotographic photosensitive member, the electrophotographic photosensitive member has at least the above formula (1) on the conductive support, An electrophotographic apparatus comprising a photosensitive layer containing the charge transport material of one of (2) or (3) and a surface protective layer containing conductive particles. 16. When the ratio of the conductive particles coating the charged particle carrier is defined as the coverage Rc, 0.2 ≦ Rc
The electrophotographic apparatus according to claim 15, wherein ≦ 1. 17. The electrophotographic apparatus according to claim 15, wherein the surface roughness Ra of the charged particle carrier is 1 to 500 μm, and the surface resistance is 10 ⁴ to 10 ¹⁰ Ω · cm. 18. The electrophotographic apparatus according to claim 15, wherein the charged particle carrier is an elastic body having a porous body surface. 19. The charged particle supplying means for supplying charged particles having a resistance of 10 ¹² to 10 ⁻¹ Ω · cm and supplying the particles to the surface of the charged particle carrier. The described electrophotographic apparatus. 20. The electrophotographic apparatus according to claim 19, wherein the charged particle supplying means directly coats the charging member. 21. The electrophotographic apparatus according to claim 19, wherein the charged particle supplying means directly coats the electrophotographic photosensitive member. 22. When the charged particles are stored in the developing means together with a developer, transferred to the photosensitive member and transferred to the recording medium, a part of the charged particle supplying device is not transferred to the photosensitive member. The electrophotographic apparatus according to claim 19, wherein the electrophotographic apparatus remains on the body and is supplied to the charging means. 23. The electrophotographic apparatus according to claim 15, wherein a cleaning unit is not provided between the transfer process and the primary charging process. 24. The electrophotographic apparatus according to claim 15, wherein the charged particles are positively charged. 25. The electrophotographic apparatus according to claim 15, wherein the charged conductive particles are positively charged with respect to the iron powder carrier. 26. When the conductive particles are stored in a developing means together with a developer, transferred onto the photoconductor, and transferred to a recording medium, a part of the conductive particles is not transferred and remains on the photoconductor. 23. The electrophotographic apparatus according to claim 22, wherein in the charging means supplied to the charging device, the conductive particles are positively charged in the developing device. 27. The electrophotographic apparatus according to claim 15, wherein the photosensitive layer is a layer in which a charge generation layer and a charge transport layer are laminated in this order. 28. The electrophotographic apparatus according to claim 15, wherein the photosensitive layer is a layer containing a charge generating material and a charge transporting material. 29. The electrophotographic apparatus according to claim 15, wherein the binder resin used for the surface protective layer is a curable resin. 30. The electrophotographic apparatus according to claim 15, wherein the conductive particles are a metal or a metal oxide. 31. The electrophotographic apparatus according to claim 15, wherein the conductive particles are treated to be water repellent. 32. The electrophotographic apparatus according to claim 15, wherein the surface protective layer contains lubricating particles. 33. The electrophotographic apparatus according to claim 32, wherein the lubricating particles are at least one of fluorine atom-containing resin particles, silicon particles, alumina particles and silicone particles. 34. A charged particle carrier having a conductive particle having a particle diameter of 10 μm to 10 nm as a main component, and a surface having conductivity and elasticity, the charged particle carrying member carrying the charged particle, In the process cartridge in which the charged particles come into contact with the electrophotographic photosensitive member and directly inject charges into the surface of the electrophotographic photosensitive member to charge the electrophotographic photosensitive member, the electrophotographic photosensitive member has at least the above formula (1), ( 2) or (3)
A process cartridge having a photosensitive layer containing one of the above charge transport materials and a surface protective layer containing conductive particles. 35. When the ratio of the conductive particles coating the charged particle carrier is defined as the coverage Rc, 0.2 ≦ Rc
The process cartridge according to claim 34, wherein ≦ 1. 36. The process cartridge according to claim 34, wherein the charged particle-supporting member has a surface roughness Ra of 1 to 500 μm and a surface resistance of 10 ⁴ to 10 ¹⁰ Ω · cm. 37. The process cartridge according to claim 34, wherein the charged particle carrier is an elastic body having a porous body surface. 38. The method according to claim 34, further comprising charged particles having a resistance of 10 ¹² to 10 ⁻¹ Ω · cm, and having charged particle supplying means for supplying the particles to the surface of the charged particle carrier. Process cartridge described. 39. The process cartridge according to claim 38, wherein the charged particle supplying means directly coats the charging member. 40. The process cartridge according to claim 38, wherein the charged particle supplying means directly coats the electrophotographic photosensitive member. 41. When the charged particle supplying means stores charged particles in a developing means together with a developer, transfers the charged particles onto the photosensitive member and is transferred to a recording medium, a part of the photosensitive particle is not transferred and is exposed. 39. The process cartridge according to claim 38, wherein the process cartridge remains on the body and is supplied to the charging means. 42. The process cartridge according to claim 34, wherein a cleaning unit is not provided between the transfer process and the primary charging process. 43. The process cartridge according to claim 34, wherein the charged particles are positively charged. 44. The process cartridge according to claim 34, wherein the charged conductive particles are positively charged with respect to the iron powder carrier. 45. When the conductive particles are stored in a developing means together with a developer, transferred to the photoconductor, and transferred to a recording medium, a part of the conductive particles is not transferred and remains on the photoconductor. 42. The process cartridge according to claim 41, wherein in the charging unit supplied to the charging device, the conductive particles are positively charged in the developing device. 46. The process cartridge according to claim 34, wherein the photosensitive layer is a layer in which a charge generation layer and a charge transport layer are laminated in this order. 47. The process cartridge according to claim 34, wherein the photosensitive layer is a layer containing a charge generating material and a charge transporting material. 48. The process cartridge according to claim 34, wherein the binder resin used for the surface protective layer is a curable resin. 49. The process cartridge according to claim 34, wherein the conductive particles are metal or metal oxide. 50. The process cartridge according to claim 34, wherein the conductive particles are water-repellent treated. 51. The process cartridge according to claim 34, wherein the surface protective layer contains lubricating particles. 52. The process cartridge according to claim 51, wherein the lubricating particles are at least one of fluorine atom-containing resin particles, silicon particles, alumina particles and silicone particles.