JP2003005411A - Electrophotographic photoreceptor, process cartridge and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor, a process cartridge and an electrophotographic device which can stably perform injection electrification and can stably supply high-quality images without causing stripes or out-of-focus images in a vibration test assuming the transportation of product distribution. SOLUTION: The photoreceptor is used for an electrophotographic device having an electrifying means which is composed of electrifying particles containing conductive particles of 10 μm to 10 nm particle size as the main component and a carrying body for electrifying particles to carry the electrifying particles, the surface of the carrying body having conductivity and elasticity and in which the electrifying particles are in contact with the photoreceptor to electrify the surface of the photoreceptor, the particles carried on the carrying body have 10<12> Ω.cm to 10<-1> Ω.cm resistance and the amount of the particles carried ranges from 0.1 mg/cm<2> to 50 mg/cm<2> . The above photoreceptor has at least a photosensitive layer and a charge injection layer on a conductive supporting body and shows the oxidation potential (Eox) of the charge transfer material used for the photosensitive layer satisfying the formula (1): 0.60 (V)<=Eox<0.80 (V). The electrophotographic device and the process cartridge are equipped with the above photoreceptor.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrophotographic photoreceptor,
More specifically, the present invention relates to a process cartridge and an electrophotographic apparatus having the electrophotographic photoconductor, and more specifically, an electrophotography using a charging system in which charging is predominantly injecting charges from a charging member in contact with the electrophotographic photoconductor onto the surface of the photoconductor The present invention relates to a photoconductor, a process cartridge having the electrophotographic photoconductor, and an electrophotographic apparatus.

[0002]

2. Description of the Related Art In the electrophotographic method, for example, charging, exposure, exposure to an electrophotographic photosensitive member such as selenium, cadmium sulfide, zinc oxide, amorphous silicon or an organic photoconductor.
Basic processes such as development, transfer, and fixing are performed, but when this is done, most of the charging processes are conventionally performed on the metal wire at high voltage (DC5-8k).
V) is applied, and charging is performed by the generated corona. However, in this method, when corona occurs, the surface of the photoconductor is altered by corona products such as ozone and NOx,
There are problems such as image blurring and deterioration, wire stains affecting image quality, and image white spots and black streaks.

In particular, an electrophotographic photosensitive member whose photosensitive layer is mainly composed of an organic photoconductor has lower chemical stability than other selenium photosensitive members and amorphous silicon photosensitive members and is exposed to corona products. Then, a chemical reaction (mainly an oxidation reaction) occurs, which tends to cause deterioration. Therefore, when repeatedly used under corona charging, there is a tendency that the image blurring due to the above-mentioned deterioration and the sensitivity decrease, the copy density becomes low due to the increase of the residual potential, and the printing (copying) resistance life becomes short.

In the case of corona charging, the electric current flowing toward the photosensitive member is 5% to 30% of the electric power, and most of the electric current flows to the shield plate, which is inefficient as a charging means. Furthermore, the concentration of ozone, NOx and the like increases by repeating the electrophotographic process by corona charging, which has been a serious problem in providing a comfortable use environment.

Therefore, in order to compensate for such problems,
For example, JP-A-57-178267 and JP-A-56
-104351, JP-A-58-40566, JP-A-58-139156, and JP-A-58-
As proposed in Japanese Patent No. 150975, etc., a method of contacting and charging without using a corona discharger has been studied. To put it concretely, 1-2k from the outside
In this system, a charging member such as a conductive elastic roller to which a DC voltage of about V is applied is brought into contact with the surface of the photoconductor to charge the surface of the photoconductor to a predetermined potential.

However, this direct charging method is disadvantageous in comparison with the corona charging method in terms of nonuniform charging and occurrence of dielectric breakdown of the photosensitive member due to discharge when a voltage is directly applied. Here, due to the non-uniformity of charging, the length 2 to 200 is perpendicular to the moving direction of the surface to be charged.
mm or less than 0.5 mm in width, streak-like charging unevenness may occur, and white streaks (a phenomenon that white streaks appear in a solid black or halftone image) that occur in the case of a positive development method or a reversal development method. In this case, image defects such as black streaks occur.

A method has been proposed in which an AC voltage is superimposed on a DC voltage and applied to a charging member in order to solve such problems and improve the uniformity of charging (JP-A-63-63).
(See Japanese Patent Publication No. 149668). In this charging method, a pulsating voltage is obtained by superimposing an AC voltage (Vac) on a DC voltage (Vdc), and this is applied to perform uniform charging.

In this case, while maintaining the uniformity of charging, white spots in the positive development system, black spots in the reversal development system,
In order to prevent image defects such as fogging, it is necessary that the superimposed AC voltage has a peak-to-peak potential difference (Vpp) that is at least twice the discharge start voltage Vth according to Paschen's law.

However, if the superposed AC voltage is increased in order to prevent image defects, the maximum applied voltage of the pulsating current voltage causes dielectric breakdown due to discharge at a slight defective portion inside the photosensitive member. In particular, when the photoconductor is an organic photoconductor having a low withstand voltage, this dielectric breakdown is remarkable. In this case, in the positive development method, the image is white in the longitudinal direction of the contact portion (in the width direction of the recording material), and in the reverse development method, black stripes occur. Also, since the discharge is in a minute gap, the damage to the photoconductor is large, and the photoconductor is greatly scraped,
There was a problem that durability was inferior.

In order to solve these problems, the inventors of the present invention injected the charge directly onto the photosensitive member,
A process of charging is being studied. Furthermore, it was also found that, in the process of direct injection of electric charges, by superposing the AC voltage, the charging becomes more stable than in the case where only the DC voltage is applied.

There is a big difference between the case where the charging that directly injects the charges onto the photosensitive member is dominant and the case where the discharging is dominant. That is, as shown in FIG. 1, in the case of discharging, the difference is that the discharge is started only when the voltage applied to the charging member is equal to or higher than the discharge start voltage, and thereafter the photosensitive member is exposed by the amount by which the applied voltage exceeds the discharge start voltage. It is charged on the body. That is, in the case of discharge charging with only DC voltage, the applied voltage V
The relationship between dc and the photoreceptor surface potential Vd is as shown in equation (6). In FIG. 1, the horizontal axis (V) is the voltage Vd applied from the power source.
c (V). However, the dark attenuation of Vd is not taken into consideration.

| Vd | ≈ | Vdc | − | Vth | Equation (6) where Vth (discharge starting voltage) = (7737.7 × D) ^1/2 +
312 + 6.2 × D D = L (photosensitive member film thickness μm) / K (photosensitive layer relative dielectric constant)

On the other hand, in the charging in which the injection charging is dominant, as shown in FIG. 1, the applied voltage of the charging member and the surface potential of the photosensitive member are almost the same, and the threshold value such as the discharge starting voltage in the case of discharging is set. Another feature is that they do not have it. It is difficult to define injection charging as the dominant charging, but there is a possibility that injection charging has occurred at least when the following expression (7) is satisfied.

[0014]     | Vdc |-| Vd | <| Vth | Equation (7)

However, under this condition, the expression (7) is satisfied even if injection charging does not occur when the photoreceptor surface potential Vd becomes higher due to frictional charging or when the resistance of the charging member becomes abnormally high. There is a possibility. Furthermore, equation (6)
Is discharge charging, injection charging may occur when the value of (Vdc-Vd) in the formula (7) is close to Vth, but it is more appropriate that the discharge is dominant. Let's do it. Therefore, assuming that the discharge-dominant charging is represented by the formula (8), | Vth / 2 | <| Vdc | − | Vd | <Vth Formula (8) The injection-dominant charging is represented by the formula (3). It is easy to understand if it is defined as.

[0016]     | Vdc | − | Vd | ≦ | Vth / 2 | Equation (3)

Consider a case where an alternating voltage Vac (V) in addition to the DC voltage Vdc is simultaneously applied from the primary charging member to the photosensitive member with reference to FIG. This charging is generally called an AC / DC superposition system.
The peak-to-peak voltage of the alternating voltage Vac is Vpp
In the case of (V), in the case of discharge charging, if Vpp is set so as to satisfy the following expression (9) in order to stabilize the charging, the photoreceptor surface potential becomes as shown in expression (10).

[0018]     | Vpp | ≧ 2 × | Vth | Equation (9)     | Vd | ≈ | Vdc | Equation (10)

That is, at the time of AC / DC discharge charging, the voltage applied to the primary charging member is set so as to satisfy the condition of formula (9) in order to stabilize the charging property.

However, when Vpp is in the condition as expressed by the formula (4), the surface potential of the photosensitive member becomes a value as expressed by the formula (11).

[0021]     | Vpp | <2 × | Vth | Equation (4)     | Vd | ≈ | Vpp / 2 | + | Vdc | − | Vth | Equation (11)

That is, assuming that the DC component Vdc (V) of the applied voltage and the discharge start voltage Vth (V) are constant, when the peak-to-peak voltage Vpp (V) of the alternating voltage is gradually decreased, the surface of the photoconductor is gradually reduced. The potential Vd (V) decreases accordingly, and when Vpp becomes 0, it becomes similar to the DC charging and becomes the same as the expression (6). Further, in consideration of the dark decay of the photoconductor, the expression (11) may be more accurate as the expression (12).

[0023]     | Vd | ≦ | Vpp / 2 | + | Vdc | − | Vth | Equation (12)

On the other hand, A in charging in which injection charging is dominant
In the C / DC superposition system, the AC component has a strong auxiliary meaning, and Vpp is usually not so strong. That is,
Vpp is given so that the equation (4) is satisfied. Here, the injection charging is largely different from the discharge system in that, in the charging in which the injection charging is dominant, the surface potential of the photoconductor is almost the same as the DC component of the voltage applied to the charging member.
That is, in the charging in which the injection charging is dominant, the formula (1
0) holds. Further, the equation (5) is established instead of the equation (12).

[0025]     | Vd |> | Vpp / 2 | + | Vdc |-| Vth | Equation (5)

As described above, it is understood that the charging method in which the injection charging is dominant and the discharge charging method are completely different charging methods both when only DC is applied from the charging member and when the AC / DC superposition system is used. In the charging in which injection charging is predominant, the electric charge is directly injected onto the photoconductor, so that it is not accompanied by discharge, or is slight even if accompanied with discharge, so that there is little deterioration due to NOx or ozone due to discharge, and There is little damage to the photoconductor, it is environmentally friendly, and it is ideal charging.

When a charging member such as a magnetic brush using various ferrite particles is used for the primary charging device for the injection charging, the contact area between the charging member and the surface of the photosensitive member is large, and the charging is relatively high. Stable, but like the present invention,
If the charging member is an elastic body, the cost can be reduced easily, but the contact area between the charging member and the surface of the photosensitive member is small,
Generally, the charging property is not so good. Therefore, in order to improve the charging property, conductive particles are carried on the contact surface between the charging member and the photosensitive member, and the surface of the charging member is provided with a speed difference with respect to the photosensitive member to increase the contact area with the photosensitive member surface. It is increased to stabilize the charging property. Therefore, the charging member rubs against the photoconductor considerably more strongly than it does during normal discharge charging, and the charging roller and the photoconductor are separated from each other by a vibration test or the like assuming transport in physical distribution. There is a problem that a rubbing memory or the like is generated at the contact portion, and the reversal developing system appears blackish and the normal developing system appears as a whitish streak image, or the image at the contact portion is blurred.

[0028]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic device capable of stable injection charge and stable supply of high-quality images in a vibration test assuming transportation in physical distribution, without streaks and image blurring. To provide a photographic device and a process cartridge.

[0029]

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. The charged particles have a charging means for contacting the electrophotographic photosensitive member and charging the surface of the electrophotographic photosensitive member, and the resistance of the particles supported on the supporting member is 10 ¹² to 10 ^−. a ^{1 Ω} · cm, an electrophotographic photosensitive member carrying amount of the particles are used in an electrophotographic apparatus is ^{0.1mg / cm 2 ~50mg / cm 2} , on the electrophotographic photosensitive member is electrically conductive support It has at least a photosensitive layer and a charge injection layer, and the oxidation potential (E
This can be solved by using an electrophotographic photosensitive member characterized in that the value of ox) satisfies the following formula (1).

[0030]         0.60 (V) ≦ Eox <0.80 (V) Formula (1)

Further, according to the present invention, there are provided a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

[0032]

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

The inventor of the present invention has found that when a voltage is not applied to the charging member when the charging member moves strongly against the photosensitive member with a speed difference, especially immediately before the rotation of the photosensitive member is stopped, the charging member remains in strong contact with the photosensitive member. The vibration test was used assuming that the product was transported by physical distribution. If the oxidation potential of the charge transport material is too high in the vibration test, etc., the charges (usually considered as positive charges) charged on the photoreceptor by frictional charging, etc., pass through the charge injection layer, and the charge injection layer It is believed that the charge is accumulated at the interface between the charge transport layer and the charge transport layer, and an electric field is constantly applied to the photosensitive layer, resulting in memory and image defects such as black streaks. On the other hand, when the oxidation potential of the charge transport material is too low, the charge transport material passes through the charge injection layer and enters the charge transport layer to deteriorate the charge transport material, or the image is blurred only for that portion for other reasons. The reason has not been clarified yet. Therefore, by controlling the oxidation potential (Eox) of the charge transporting material used for the photosensitive layer below the charge injection layer to fall within the range shown in the above formula (1), the electric charge escapes without accumulating.
The rubbing memory can be suppressed, the deterioration of the charge transport material can be prevented, and the above problems are considered to be solved.

First, the charging method in the present invention will be described.

The charger according to the present invention shown in FIG.
A conductive elastic roller 2 (hereinafter, referred to as a charging roller), conductive particles 3 (hereinafter, referred to as charged particles) mainly for the purpose of accelerating charging, and a regulation member 4 which is a charged particle supply unit.
Composed of. In the contact nip n between the charging roller and the electrophotographic photosensitive member 1, the photosensitive member 1 is charged while the charged particles 3 are applied. As a result, the charging roller 2 can contact the electrophotographic photosensitive member 1 with a speed difference, and at the same time,
It is possible to directly inject charges into the photoconductor 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 as the voltage corresponding to the potential required for the photoconductor, and a safe charging method that does not use the discharge phenomenon can be 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. Then, if necessary, the surface was polished to prepare an elastic conductive roller 2 having a diameter of 12 mm and a longitudinal length of 230 mm. When the roller resistance of this embodiment was measured, it was 100 kΩ. 100 V was applied to the core metal 2a and the aluminum drum in a state where the core metal of the roller 2 was pressure-bonded to an aluminum drum of φ30 mm so that a total pressure of 1 kg was applied, and measurement was performed. Here, it is important that the elastic roller 2 functions 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 electrophotographic photosensitive member is used as the member to be charged, 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, resulting in poor contact. If it is too high, the charging nip cannot be ensured and the microscopic contact with the surface of the photoreceptor 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.

<Charge-Promoting Particles> In this embodiment, conductive zinc oxide particles 3 having a specific resistance of 10 ⁶ Ω · cm and an average particle size of 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. Into a cylinder with a bottom area of 2.26 cm ² , put 0.5 g of powder sample into the upper and lower electrodes, apply 15 kg of pressure to the upper and lower electrodes, and simultaneously apply a voltage of 100 V to measure the resistance.
After that, the resistivity was normalized and calculated. The particle size is preferably equal to or smaller than the constituent pixel size in order to obtain good charging uniformity. The lower limit of the particle size is 10 nm as a limit for stably obtaining the particles. 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 horizontal chord length.
It was determined by its 50% average particle size.

<Charging-promoting particle coating means> Charging-promoting particles 3
In order to uniformly supply the toner to the contact nip n between the charging roller and the photoconductor 1, charging-promoting particle coating means is provided. As a supply means, the regulating blade 4 is brought into contact with the photoconductor 1 to
The charging promotion particles 3 are held between the control blade 4 and the regulation blade 4. Then, as the photoconductor 1 rotates, a fixed amount of the charging promoting particles 3 is applied to the charging roller 2. As a simpler configuration, there is a method of bringing a foamed body or a fur brush containing the electrification accelerating particles 3 into contact with an object to be charged, but the present invention is not limited to this configuration. In the present invention, the charging member is rotated with a speed difference with respect to the body to be charged. Therefore, the vicinity of the contact nip of the charging member composed of an elastic body is largely deformed as compared with the case of being driven, and the particles adhering to the surface of the charging member easily migrate to the charged body, and the device is used. As a result, the particles on the surface of the charging member decrease. Therefore, the configuration is such that a fixed amount of charge promoting particles is always supplied.

<Operation of Charging Device> In the present embodiment, the charged body is assumed to be a photoconductor for electrophotography. The member to be charged 1 has a drum shape and rotates at a constant peripheral speed. A charger that uniformly charges this surface was used. First, the charging accelerating particles 3 are applied to the surface of the photoconductor by the regulating blade 4. After that, it reaches the charging roller portion.
The charging roller 2 was driven so that the roller surface moved in the opposite direction to the photoconductor at a constant speed, and a DC voltage was applied to the roller core metal 2a. As a result, the surface of the photoconductor is charged to a potential equal to the applied voltage. In the present embodiment, the charging is performed directly by the charging promoting particles 3 existing in the contact nip between the roller and the body to be charged slidingly covering the surface of the body to be charged without a gap.

Next, the overall schematic configuration of this embodiment will be described with reference to FIG.

Reference numeral 1 denotes a rotary drum type electrophotographic photosensitive member as an image bearing member, which is rotationally driven in the direction of an arrow at a predetermined peripheral speed (= process speed PS).

Reference numeral 2 is a charging roller as a contact charging member for the photosensitive member 1, and charging accelerating particle supplying means is arranged on the charging roller 2 side. The charging roller 2 is rotationally driven in the arrow direction with a peripheral speed difference so that the charging roller surface and the photosensitive member surface move in opposite directions in the charging nip portion n. The core metal 2a of the charging roller 2 is applied with a DC voltage of -600 V from the charging bias applying power source S1.

Therefore, as described above, the surface of the rotating photoconductor 1 is such that the charging roller 2 comes into contact with the photoconductor at a peripheral speed difference, and the charging roller 2 is charged by the charging accelerating particle supplying means. Since the accelerating particles 3 are present in the charging nip n, the charging of the photoconductor 1 by the charging roller 2 is dominated by the direct injection charging, and the charging process is performed uniformly to the same potential as the charging bias voltage applied to the charging roller 2. To be done.

Reference numeral 5 is a laser beam scanner (exposure device) including a laser diode, a polygon mirror and the like. The laser beam scanner 5 outputs laser light whose intensity is modulated corresponding to a time-series digital image signal of target image information, and scans and exposes the uniformly charged surface of the rotary photosensitive drum 1 with the laser light. The scanning exposure light L forms an electrostatic latent image on the surface of the rotary photosensitive drum 1 corresponding to the target image information.

Reference numeral 6 is a developing device. The electrostatic latent image on the surface of the rotating photoconductor 1 is developed as a toner image by this developing device. The developing device 6 is, for example, a one-component or two-component non-contact reversal developing device including a non-magnetic developing sleeve 6b containing a magnet roll 6a as a developer carrying and conveying member. Reference numeral a denotes a developing area which is a portion where the photosensitive member 1 and the developing sleeve 6b face each other. S2 is a developing bias application power source for the developing sleeve 6b.

Reference numeral 7 denotes a transfer roller as a transfer means, which is pressed against the photosensitive member 1 at a predetermined pressure to form a transfer nip portion b. A transfer material P as a recording medium is fed to the transfer nip portion b from a paper feed portion (not shown) at a predetermined timing, and a predetermined transfer bias is applied to the transfer roller 7 from a power source S3, so that the photosensitive member The toner image on the first side is sequentially transferred to the surface of the transfer material P fed to the transfer nip portion b.

Reference numeral 8 is a fixing device. The transfer material P fed to the transfer nip portion b and transferred with the toner image on the side of the photoconductor 1 is separated from the surface of the rotary photoconductor 1 and introduced into the fixing device 8, where the toner image is fixed and the image is formed. It is discharged outside the device as a formed product (printed copy).

Reference numeral 9 is a process cartridge which can be attached to and detached from the main body of the electrophotographic apparatus. In the present embodiment, the photoconductor 1, the charging roller 2 including the charging promoting particle supply unit 4,
The three process devices of the developing device 6 are collectively configured as a process cartridge that can be attached to and detached from the main body of the electrophotographic apparatus. The combination of process equipment to be made into a process cartridge is not limited to the above, but is arbitrary. Reference numeral 10 is a rail for guiding and holding the attachment / detachment of the process cartridge.

The charge-promoting particles 3 are preferably colorless or nearly white particles so as not to hinder the exposure of the latent image particularly when used for charging the photoreceptor 1. Further, in the case of performing color recording, in consideration of the case where the charging accelerating particles 3 are transferred from the photosensitive member to the transfer material P, those which are colorless or close to white are preferable. Further, in order to prevent light scattering by the charge-accelerating particles during image exposure, the particles are preferably smaller than or equal to the constituent pixel size.

Next, the layer structure of the electrophotographic photosensitive member used in the present invention is shown in FIG. As the support, a cylindrical one having conductivity was used this time, but the shape may be any one, and examples of the one having conductivity include aluminum, aluminum alloy, copper, zinc, stainless steel,
Metal such as vanadium, molybdenum, chromium, titanium, nickel and indium, metal foil such as aluminum or copper laminated on plastic film, aluminum, indium oxide or tin oxide deposited on plastic film, conductive material Examples thereof include metals, plastic films, and paper which are provided alone or together with a binder resin to provide a conductive layer.

The structure of the photosensitive layer is roughly classified into a single layer type containing both a charge generating material and a charge transporting material in the same layer and a laminated type containing a charge generating layer and a charge transporting layer. In terms of characteristics, the laminated type is preferable.

When the photosensitive layer is a laminated type, the charge generating material may be an inorganic charge generating material such as selenium, selenium-tellurium or amorphous silicon; a pyrylium dye, a thiapyrylium dye, an azurenium dye, a thiacyanine dye and a quinocyanine. Cationic dyes such as system dyes; Squarium salt pigments; Phthalocyanine pigments; Polycyclic quinone pigments such as anthanthrone pigments, dibenzpyrenequinone pigments and pyrantrone pigments; Indigo pigments; Quinacridone pigments; and Azo pigments Examples include pigments and the like. The charge generation layer can be formed as a vapor deposition layer of these charge generation materials by a vacuum vapor deposition apparatus, or can be formed as a coating layer by applying a coating liquid dispersed or dissolved in a binder resin and drying. .

The binder resin can be selected from a wide range of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole and polyvinylpyrene. Preferably, polyvinyl butyral, polyarylate (condensation polymer of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, polyvinyl acetate, acrylic resin, polyacrylamide, polyamide, cellulose resin, urethane resin, epoxy resin, polyvinyl alcohol, etc. Resins of

The binder resin contained in the charge generation layer is preferably 80% by mass or less, more preferably 50% by mass or less, based on the total mass of the charge generation layer. The thickness of the charge generation layer is preferably 5 μm or less, and particularly preferably 0.01 to 1 μm.

The charge transport layer comprises a polycyclic aromatic compound having a structure such as biphenylene, anthracene, pyrene and phenanthrene in the main chain or side chain; a nitrogen-containing ring compound such as indole, carbazole, oxadiazole and pyrazoline; hydrazone compound And a charge transport material such as a styryl compound dissolved in a binder resin is applied and dried.

As the binder resin, polyarylate, polysulfone, polyamide, acrylic resin, acrylonitrile resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenol resin, epoxy resin, polyester resin, alkyd resin, polycarbonate resin, polyurethane, Alternatively, copolymers thereof, for example, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer and the like can be mentioned. In addition to such an insulating polymer, an organic photoconductive polymer such as polyvinylcarbazole, polyvinylanthracene, or polyvinylpyrene can also be used.

The ratio of the binder resin to the charge transport material is preferably 10 to 500 parts by weight of the charge transport material per 100 parts by weight of the binder resin. The thickness of the charge transport layer is preferably 5 to 40 μm, particularly preferably 10 to 30 μm.

When the photosensitive layer is of a single layer type, the photosensitive layer is prepared by applying a solution prepared by dispersing and dissolving the above-mentioned charge generating material and charge transporting material in the above-mentioned binder resin onto a support and drying it. Can be formed.

In the present invention, an undercoat layer having a barrier function and an adhesive function may be provided between the support and the photosensitive layer. As the material of the undercoat layer, polyvinyl alcohol,
Examples thereof include polyethylene oxide, nitrocellulose, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, alcohol-soluble amide, polyamide, polyurethane, casein, glue and gelatin.
The undercoat layer can be formed by applying a solution prepared by dissolving these materials in a suitable solvent onto a support and drying. The film thickness is preferably 5 μm or less, and particularly preferably 0.2 μm to 3 μm.

When the exposure light is laser light, a conductive layer is preferably provided between the undercoat layer and the support in order to prevent interference fringes. The conductive layer can be formed by applying a solution in which a conductive powder such as carbon black and metal particles is dispersed in a binder resin on a support and drying the solution. The thickness of the conductive layer is preferably 5 to 40 μm, and particularly preferably 5 to 30 μm.

The above-mentioned various layers are formed by a coating method such as a dip coating method, a spray coating method, a beam coating method, a spinner coating method, a roller coating method, a Meyer bar coating method and a blade coating method using an appropriate organic solvent. can do.

Next, the charge injection layer of the electrophotographic photosensitive member used in the present invention will be described.

In the present invention, examples of the conductive particles used in the charge injection layer include metals, metal oxides, carbon black and the like. As the metal, aluminum,
Examples thereof include zinc, copper, chromium, nickel, silver and stainless steel, or those obtained by vapor-depositing these metals on the surface of plastic particles. As the metal oxide, zinc oxide,
Titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide,
Examples thereof include tin oxide doped with antimony and 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 average particle size of the conductive particles used in the present invention is preferably 0.3 μm or less, and particularly preferably 0.1 μm or less, from the viewpoint of transparency of the charge injection layer.

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

The lubricating particles used in the present invention are at least one of fluorine atom-containing resin particles, silicone particles, silicon particles and alumina particles, but fluorine atom-containing resin particles are more preferable. Fluorine atom-containing resin particles include tetrafluoroethylene resin, trifluoroethylene chloride resin, hexafluoroethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluorodichloroethylene resin and copolymers thereof. It is preferable to appropriately select one kind or two or more kinds from the combination, and especially a tetrafluoroethylene resin and a vinylidene fluoride resin are preferable. The molecular weight of the resin particles and the particle size of the particles can be appropriately selected and are not particularly limited. Although inorganic particles such as silicon particles and alumina particles may not work as lubricating particles alone, by dispersing and adding them, the surface roughness of the charge injection layer becomes large, and It has been known by the present inventors that the number of contact points is smaller than that of the one in contact with, and consequently the lubricity of the charge injection layer is increased. Lubricant particles here are
Particles that impart lubricity are also included.

The fluorine atom-containing resin particles together with the conductive particles should be prevented from aggregating with each other in the resin solution.
The fluorine atom-containing compound may be added during dispersion of the conductive particles, or the surface of the conductive particles may be surface-treated with the fluorine atom-containing compound. By adding a fluorine atom-containing compound or subjecting the conductive particles to a surface treatment, the dispersibility and dispersion stability of the conductive particles and the fluorine atom-containing resin particles in the resin solution are higher than in the case where there is no fluorine atom-containing compound. Has improved significantly. In addition, by forming a secondary particle of dispersed particles by dispersing fluorine atom-containing resin particles in a liquid in which a fluorine atom-containing compound is added and conductive particles are dispersed, or in which a surface-treated conductive particle is dispersed. In addition, a coating liquid that is very stable and has good dispersibility over time can be obtained.

Examples of the fluorine atom-containing compound in the present invention include a fluorine-containing silane coupling agent, a fluorine-modified silicone oil and a fluorine-based surfactant.
Examples of preferable compounds are shown in Tables 1 to 3, but the present invention is not limited to these compounds.

[0073]

[Table 1]

[0074]

[Table 2]

[0075]

[Table 3]

As a method of surface-treating the conductive particles, the conductive particles and the surface-treating agent are mixed and dispersed in a suitable solvent,
A surface treatment agent is attached to the surface of the conductive particles. As a dispersing method, a usual dispersing means such as a ball mill or a sand mill can be used. Next, the solvent may be removed from this dispersion solution and fixed on the surface of the conductive particles. Further, if necessary, a heat treatment may be further performed thereafter. Also,
A catalyst for accelerating the reaction can be added to the treatment liquid. Furthermore, if necessary, the surface-treated conductive particles can be further pulverized.

The ratio of the fluorine atom-containing compound to the conductive particles is influenced by the particle size of the particles, but is preferably 1 to 65 mass% with respect to the total mass of the surface-treated conductive particles,
Particularly, 1 to 50 mass% is preferable.

As described above, the dispersion of the fluorine atom-containing resin particles can be achieved by dispersing the conductive particles after adding the fluorine atom-containing compound or by using the conductive particles surface-treated with the fluorine atom-containing compound. It is possible to form a charge injection layer that is stable and has excellent slipperiness and releasability. However, due to recent progress in colorization, higher image quality, and higher stability, there has been a demand for more environmental stability, and the charge injection layer has also required more environmental stability.

As the binder resin for the charge injection layer used in the present invention, the environmental change of the resistance of the charge injection layer is small,
A curable phenol resin was used in terms of hard surface hardness, excellent abrasion resistance, dispersibility of fine particles, and stability after dispersion. In consideration of productivity, thermosetting resol type phenol resin is more preferable.

Further, in the present invention, in order to form a charge injection layer having more environmental stability, a siloxane compound represented by the following general formula (1) is added at the time of dispersing conductive particles, or a surface treatment is performed in advance. It was possible to obtain a charge injection layer which was more excellent in environmental stability by mixing the conductive particles subjected to the above.

[0081]

[Chemical 4]

In the formula, A is a hydrogen atom or a methyl group,
Moreover, the ratio of hydrogen atoms in all A is 0.1 to 50.
%, N is an integer of 0 or more.

A coating solution in which the siloxane compound is dispersed or a surface-treated conductive metal oxide fine particle is dispersed together with a solvent, and a binder resin is further added to form secondary particles of dispersed particles. A coating liquid that was stable and stable over time was obtained without formation, and the charge injection layer formed from this coating liquid was highly transparent and a film with particularly excellent environmental resistance was obtained. . Further, when the resin used for the charge injection layer is a curable phenol resin, it may be seen that streaky unevenness or cells are formed depending on the film thickness of the charge injection layer or other conditions. By adding the compound or using the conductive fine particles surface-treated, it was possible to suppress the formation of streaky unevenness and cells, and there was an unexpected effect of the leveling agent.

The molecular weight of the siloxane compound represented by the general formula (1) is not particularly limited, but when the surface treatment is performed, it is better that the viscosity is not too high because of its easiness, and the weight average molecular weight is A few hundred to tens of thousands is suitable.

There are two types of surface treatment methods, wet type and dry type. In the wet method, the conductive metal oxide particles are dispersed in a solvent with a siloxane compound represented by the general formula (1), and the siloxane compound is attached to the surface of the fine particles. As a dispersing means, a general dispersing means such as a ball mill or a sand mill can be used. Next, this dispersion solution is fixed to the surface of the conductive metal oxide fine particles. In this heat treatment, the Si—H bond in siloxane undergoes oxidation of hydrogen atoms due to oxygen in the air during the heat treatment process to form a new siloxane bond. As a result, siloxane develops into a three-dimensional structure, and the surface of the conductive metal oxide fine particles is covered with this network structure. In this way, the surface treatment is completed by fixing the siloxane compound to the surface of the conductive metal oxide fine particles, but the fine particles after the treatment may be subjected to a crushing treatment, if necessary. In the dry treatment, the siloxane compound and the conductive metal oxide fine particles are mixed and kneaded without using a solvent to adhere the siloxane compound to the fine particle surface. After that, the surface treatment is completed by performing heat treatment or pulverization treatment as in the wet treatment.

The ratio of the siloxane compound to the conductive metal oxide fine particles in the present invention depends on the particle size of the fine particles, the ratio of methyl groups to hydrogen atoms in siloxane, and the like.
-50 mass% is preferable, and especially 3-40 mass% is preferable.

The binder resin for the charge injection layer used in the present invention is preferably a curable resin, and particularly preferably an acrylic resin, an epoxy resin, a polyurethane resin, or a siloxane resin. Above all, it is preferable to use the phenol resin because the environmental change of the resistance of the charge injection layer is small. Furthermore, it is more preferable to use a curable phenol resin, particularly a thermosetting resol type phenol resin, from the viewpoints of hard surface hardness, excellent abrasion resistance, dispersibility of fine particles, and excellent stability after dispersion. preferable.

Usually, the resol type phenol resin is produced by subjecting a phenol compound and an aldehyde compound to an alkali catalyst. The main phenols used include, but are not limited to, phenol, cresol, xylenol, paraalkylphenol, paraphenylphenol, resorcin and bisphenol. The aldehydes include, but are not limited to, formaldehyde, paraformaldehyde, furfural, acetaldehyde and the like.

Monomers of phenols, dimethylolphenols, trimethylolphenols, and their mixtures, or their oligomers, which are obtained by reacting these phenols with aldehydes under an alkaline catalyst, and Make a mixture of monomers and oligomers. Of these, relatively large molecules in which the structural units of the molecule are repeated 2 to 20 are oligomers and 1
One is a monomer.

The alkali catalysts used include metal-based alkali compounds, ammonia and amine compounds, and the metal-based alkali compounds include NaOH and KOH.
And alkali metal and alkaline earth metal hydroxides such as Ca (OH) _{2 and the} like, and amine compounds include, but are not limited to, ammonia, hexamethylenetetramine, trimethylamine, triethylamine and triethanolamine. Not something. In the present invention, it is preferable to use ammonia and an amine compound in consideration of the variation in resistance under a high humidity environment.
Considering the stability of the solution, it is more preferable to use an amine compound.

The phenolic resin used in the protective layer in the present invention is curable, and more preferably thermosetting, so that it is usually cured in a hot air drying oven after being coated on the photosensitive layer. The curing temperature at this time is 100 to 200 ° C.
Is preferable, and particularly 120 to 180 ° C. is preferable.

In the present invention, "the resin is cured" means that the resin is not dissolved in an alcohol solvent such as methanol or ethanol.

The ratio between the resin and the conductive particles is a value that directly determines the resistance of the charge injection layer, and the volume resistance of the charge injection layer which can be stably charged by injection is 10 ¹⁰ to 10 ¹⁵ Ω · c.
It is preferable to set it within the range of m, especially 1
It is preferably 0 ¹⁰ to 10 ¹⁴ Ω · cm. Since the film strength becomes weaker as the amount of the conductive particles increases, it is preferable to reduce the amount of the conductive particles within a range in which the resistance and residual potential of the charge injection layer are allowable.

The thickness of the charge injection layer is 0.1 to 10 μm.
m is preferable, and particularly 0.5 to 7 μm is preferable.

In the present invention, additives such as a coupling agent and an antioxidant may be added for the purpose of improving dispersibility, binding property and weather resistance during the injection of the charge retention.

The oxidation potential of the charge transport material was measured by the three-electrode type cyclic voltammetry using the following materials.

Electrode: working electrode (glassy carbon electrode), counter electrode (platinum electrode) Reference electrode: saturated calomel electrode (0.1 mol / liter KCl-aqueous solution) Measurement solution Electrolyte: t-butylammonium perchlorate
1 mol measuring substance: 0.001 mol solvent for charge transfer agent (hole): acetonitrile 1 liter or more was prepared to prepare a measurement solution. The peak top of the first oxidation potential of the measurement result was defined as the oxidation potential of the charge transport material.

[0098]

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

(Example 1) φ30 mm × 260.5 mm
Was used as a support, and a 5% by mass methanol solution of a polyamide resin (trade name: Amilan CM8000, manufactured by Toray) was applied onto the aluminum cylinder by a dipping method to form an undercoat layer having a thickness of 0.5 μm.

Next, the Bragg angle (2θ ± 0.2 °) of CuKα characteristic X-ray diffraction represented by the following equation (2) was 9.0.
4 parts of oxytitanium phthalocyanine pigment having strong peaks at °, 14.2 °, 23.9 ° and 27.1 °,

[0101]

[Chemical 5] 2 parts of polyvinyl butyral resin (trade name: BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 80 parts of cyclohexanone
Dispersion was carried out for about 4 hours using a sand mill device using mm glass beads. This solution is coated on the undercoat layer,
It was dried with hot air at 10 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm.

Then, 10 parts of a compound of the following formula (3):

[0103]

[Chemical 6] And bisphenol Z type polycarbonate (trade name: Z
10 parts of (-200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dissolved in 100 parts of monochlorobenzene. This solution was applied on the charge generation layer and dried in hot air at 105 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm.

Next, as the charge injection layer, 20 parts of antimony-doped tin oxide ultrafine particles surface-treated with the compound of the following formula (4) (treatment amount 7%),

[0105]

[Chemical 7] Methyl hydrogen silicone oil (trade name: KF
99, manufactured by Shin-Etsu Silicone Co., Ltd.) (30% treatment amount), 30 parts of antimony-doped tin oxide fine particles and 150 parts of ethanol were dispersed in a sand mill for 66 hours, and further, polytetrafluoroethylene fine particles. 20 parts (average particle size 0.18 μm) was added and dispersed for 2 hours. Thereafter, 25 parts of a thermosetting resol-type phenol resin {trade name: PL-4804, manufactured by Gunei Chemical Industry Co., Ltd. (containing amine compound)} was dissolved as a resin component,
It was a preparation liquid.

Using this formulation, a film was formed on the above charge transport layer by a dip coating method, and dried by hot air at a temperature of 145 ° C. for 1 hour to obtain a charge injection layer. At this time, the film thickness of the obtained charge injection layer was measured using an instantaneous multi-photometry system MCPD-2000 (manufactured by Otsuka Electronics Co., Ltd.) due to light interference because the film thickness was 3 μm. It was Further, the dispersibility of the charge injection layer preparation liquid was good, and the film surface was a uniform and even surface.

For the evaluation of the test, a laser jet 4000 manufactured by Hewlett-Packard Co., Ltd. was used as an actual machine modified to the configuration shown in FIG. This charging roller was produced by forming a medium resistance layer of rubber on a core metal. 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 1
An elastic conductive roller having a length of 2 mm and a longitudinal length of 230 mm was produced. When the resistance of this roller was measured, it was 100 kΩ.
Met. 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 example, the charging nip width of the charging roller 2 was 3 mm. This charging roller was rotationally driven in the direction of the arrow at about 80 rpm so that the charging roller surface and the photoreceptor surface moved in opposite directions in the charging nip portion. That is, the surface of the charging roller 2 as the contact charging member has a speed difference with respect to the surface of the photoreceptor 1 as the member to be charged. At this time, the voltage applied to the charging member was -600 V only for DC.

In the photoconductor of this time, the discharge start voltage (Vt
h) was about 580 V, and there was no great difference between the example and the comparative example.

The conductive particles 3 are charge-assisting particles for the purpose of charge-assisting. In this example, the specific resistance is 10 ⁶ Ω · cm,
Conductive zinc oxide particles having an average particle size of 3 μm including secondary aggregates were used. The cleaner blade was removed to use a so-called cleanerless process, and residual toner after transfer was collected by a developing device.

As the evaluation, the initial dark potential (Vd) was measured and the image was evaluated. , Dark potential measurement and image evaluation were performed. Further, a vibration test was conducted assuming the influence of friction between the charging roller and the photoconductor in the cartridge and the electrophotographic apparatus, and transportation in physical distribution. The vibration test is a physical distribution test standard (JI
S Z0230), the cartridge after the initial evaluation is subjected to a vibration test device (EMIC CORP. Model 90
5-FN), frequency 10 Hz to 100 Hz, acceleration 1 G, sweep direction LIN SWEEP, reciprocating sweep time 5 minutes, test time 1 in each of the x, y, and z axis directions.
After hours, image evaluation was performed. The results are shown in Table 4.

(Example 2) Example 2 is the same as Example 1 except that the charge transporting material represented by the formula (3) used for the electrophotographic photosensitive member is replaced by the charge transporting material represented by the following formula (5). 1
Was prepared and evaluated in exactly the same manner as. The results are shown in Table 4.

[0112]

[Chemical 8]

(Example 3) Example 3 is the same as Example 1 except that the charge transporting material represented by the formula (3) used for the electrophotographic photosensitive member is replaced by the charge transporting material represented by the following formula (6). 1
Was prepared and evaluated in exactly the same manner as. The results are shown in Table 4.

[0114]

[Chemical 9]

(Example 4) Example 4 is the same as Example 1 except that the charge transporting material represented by the formula (3) used for the electrophotographic photosensitive member is replaced by the charge transporting material represented by the following formula (7). 1
Was prepared and evaluated in exactly the same manner as. The results are shown in Table 4.

[0116]

[Chemical 10]

(Comparative Example 1) Example 1 is the same as Example 1 except that the charge transporting material represented by the formula (3) used in the electrophotographic photoreceptor is replaced by the charge transporting material represented by the following formula (8). 1
Was prepared and evaluated in exactly the same manner as. The results are shown in Table 4.

[0118]

[Chemical 11]

(Comparative Example 2) Example 2 is the same as Example 1 except that the charge transporting material represented by the formula (3) used in the electrophotographic photoreceptor is replaced by the charge transporting material represented by the following formula (9). 1
Was prepared and evaluated in exactly the same manner as. The results are shown in Table 4.

[0120]

[Chemical 12]

(Comparative Example 3) Example 3 is the same as Example 1 except that the charge transporting material represented by the formula (3) used in the electrophotographic photoreceptor is replaced by the charge transporting material represented by the following formula (10). It was prepared and evaluated in exactly the same manner as 1. The results are shown in Table 4.
Shown in.

[0122]

[Chemical 13]

(Comparative Example 4) Example 4 is the same as Example 1 except that the charge transporting material represented by the formula (3) used for the electrophotographic photoreceptor is replaced by the charge transporting material represented by the following formula (11). It was prepared and evaluated in exactly the same manner as 1. The results are shown in Table 4.
Shown in.

[0124]

[Chemical 14]

(Examples 5 to 8) In Examples 1 to 4,
The thermosetting resol type phenol resin (PL-480
4) is a novolac type phenol resin (trade name: CMK-
2400, manufactured by Showa Highpolymer Co., Ltd., and prepared in the same manner as in Examples 1 to 4 except that 1 part of hexamethylenetetramine was added as a curing agent to form a charge injection layer. And evaluated. The results are shown in Table 4.

Comparative Examples 5 to 8 In Comparative Examples 1 to 4,
The thermosetting resol type phenol resin (PL-480
4) is a novolac type phenol resin (trade name: CMK-
2400 Showa High Polymer Co., Ltd.), and 1 part of hexamethylenetetramine as a curing agent was added to prepare a mixed solution.
Except that the charge injection layer was formed, it was prepared and evaluated in exactly the same manner as Comparative Examples 1 to 4. The results are shown in Table 4.

(Examples 9 to 12) In Examples 1 to 4, the feeder for the conductive zinc oxide particles, which are the auxiliary charging particles, was removed, and instead, the conductive zinc oxide particles were uniformly distributed on the charging roller. Example 1 except that after the dusting, the same conductive zinc oxide particles were externally added to the toner so that the conductive zinc oxide particles could be replenished simultaneously with the development.
The evaluation was performed in the same manner as in the above. The results are shown in Table 4.

(Comparative Examples 9 to 12) In Comparative Examples 1 to 4, the supply device for the conductive zinc oxide particles as the charging auxiliary particles was removed, and instead, the conductive zinc oxide particles were uniformly distributed on the charging roller. Comparative Example 1 except that the same conductive zinc oxide particles were externally added to the toner after the dusting so that the conductive zinc oxide particles could be replenished simultaneously with the development.
The evaluation was performed in the same manner as in the above. The results are shown in Table 4.

(Examples 13 to 16) In Examples 1 to 4, the voltage applied to the charging roller was DC-600V only, and the alternating voltage Vac was superimposed to obtain the peak-to-peak voltage Vpp. Evaluation was performed in the same manner as in Examples 1 to 4 except that the voltage was set to 200V. The results are shown in Table 4.

Comparative Examples 13 to 16 Evaluations were made in the same manner as in Examples 13 to 16 except that the charging roller in Examples 13 to 16 was returned to the standard product of Laser Jet 4000 manufactured by Hewlett Packard Co. went. The results are shown in Table 4.

(Comparative Examples 17 to 20) Evaluations were made in the same manner as in Examples 1 to 4 except that the charging roller in Examples 1 to 4 was returned to the standard product of Laser Jet 4000 manufactured by Hewlett Packard Co. I went. The results are shown in Table 4.
Shown in.

(Comparative Example 21) The same preparation and evaluation as in Example 3 except that the charge injection layer was not applied in Example 3 was carried out. The results are shown in Table 4.

[0133]

[Table 4]

[0134]

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. It has a charging means for contacting the photoconductor and charging the surface of the electrophotographic photoconductor, and the resistance of the particles carried on the carrier is 10 ¹² to 10 ⁻¹ Ω · cm, and the carried amount of the particles is in the electrophotographic photosensitive member used in an electrophotographic apparatus is ^{0.1mg / cm 2 ~50mg / cm 2} , at least a photosensitive layer and a charge injection layer electrophotographic photoreceptor is on the electrically conductive substrate and the photosensitive According to the electrophotographic photosensitive member, the value of the oxidation potential (Eox) of the charge transport material used for the layer satisfies the following formula (1): 0.60 (V) ≦ Eox <0.80 (V) (1) Injection charging can be performed stably, and Even assumed vibration test transport logistics, it becomes possible to supply stably good images without image blur for a black streak or streaks. Further, by using the process cartridge having the electrophotographic photosensitive member and the electrophotographic apparatus, injection charging can be stably performed, and black streaks and black stripes are generated even in a vibration test assuming transportation in distribution. It became possible to stably supply a good image without streaky image blur.

[Brief description of drawings]

FIG. 1 is a diagram showing a difference between discharge charging and injection charging when only a DC voltage is applied to a charging roller.

FIG. 2 is a diagram showing a difference between discharge charging and injection charging when an AC voltage is superimposed on a DC voltage and a voltage is applied to a charging roller.

FIG. 3 is a diagram showing details of a conductor of the electrophotographic apparatus of the present invention.

FIG. 4 is a diagram showing a schematic configuration of an electrophotographic apparatus provided with the process cartridge of the present invention.

FIG. 5 is a diagram showing a layer structure of the electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

1 Electrophotographic photoreceptor 2 charging roller 2a core metal 2b Conductive elastic roller 3 Charged conductive particles (charged particles) 4 regulation blade 5 Exposure equipment 6 Development device 7 Transfer member 8 fixing device 9 Process Cartridge 10 rails n Charging contact part (nip) a Development site b Transcription site P transfer material L exposure light 51 charge injection layer 52 Charge Transport Layer 53 Charge generation layer 54 Conductive support 55 Tie layer 56 Undercoat layer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/02 101 G03G 15/02 101 102 102 (72) Inventor Koichi Nakata 3-30 Shimomaruko, Ota-ku, Tokyo No. 2 Canon Inc. (72) Inventor Daisuke Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F-term (reference) 2H068 AA03 AA05 AA06 BA58 BB06 BB30 BB31 BB33 BB34 BB35 BB58 CA33 2H200 FA16 GA16 GA23 GA30 GA34 GA45 GA47 GA53 GA56 HA02 HA21 HA28 HA29 HB12 HB17 HB22 HB43 HB45 HB46 HB47 HB48 JA02 JA28 MA03 MA04 MA14 MA20 MB04 MB06 MC02 MC15 NA06 PA05 PB04

Claims (82)

[Claims] 1. A charged particle containing conductive particles having a particle size of 10 μm to 10 nm as a main component and a surface having conductivity and elasticity, and a charged particle carrier for supporting the charged particles, The charged particles have a charging means for contacting the electrophotographic photoreceptor and charging the surface of the electrophotographic photoreceptor, and the resistance of the particles carried on the carrier is 10 ¹² to 10 ⁻¹ Ω · cm, The amount of particles carried is 0.1 mg / cm ^{2 to} 50 mg /
In cm ² electrophotographic photosensitive member used in the electrophotographic apparatus is, at least a photosensitive layer and a charge injection layer electrophotographic photoreceptor is on the electrically conductive substrate and the oxidation potential of the charge transport material used for the photosensitive layer An electrophotographic photosensitive member characterized in that the value of (Eox) satisfies the following formula (1). 0.60 (V) ≦ Eox <0.80 (V) Formula (1) 2. The electrophotographic photosensitive member according to claim 1, wherein the value of the oxidation potential (Eox) of the charge transport material used for the photosensitive layer satisfies the following formula (2). 0.60 (V) ≦ Eox ≦ 0.76 (V) Formula (2) 3. The electrophotographic photoreceptor according to claim 1, wherein the charge injection layer contains at least one of conductive particles and a charge transport material, and a binder resin. 4. The electrophotographic photosensitive member according to claim 3, wherein the binder resin used for the charge injection layer is a curable resin. 5. The electrophotographic photosensitive member according to claim 3, wherein the conductive particles used for the charge injection layer are metal or metal oxide particles. 6. The electrophotographic photosensitive member according to claim 1, wherein the charge injection layer contains at least one of a fluorine atom-containing compound and a siloxane compound. 7. The electrophotographic photosensitive member according to claim 1, wherein the charge injection layer contains lubricating particles. 8. The electrophotographic photosensitive member according to claim 7, wherein the lubricating particles are at least one of fluorine atom-containing resin particles, silicone particles, silicon particles and alumina particles. 9. The fluorine-containing compound is selected from the group consisting of a fluorine-containing silane coupling agent, a fluorine-modified silicone oil and a fluorine-based surfactant.
The electrophotographic photosensitive member according to 1. 10. The siloxane compound is represented by the general formula (1):
The electrophotographic photosensitive member according to claim 6, which is a siloxane compound represented by: [Chemical 1] (In the formula, A is a hydrogen atom or a methyl group, and the proportion of hydrogen atoms in all A is in the range of 0.1 to 50%,
(n is a positive integer of 0 or more) 11. The electrophotographic photosensitive member according to claim 4, wherein the curable resin is at least one of a phenol resin, an acrylic resin, an epoxy resin, and a siloxane resin. 12. The electrophotographic photosensitive member according to claim 11, wherein the phenol resin is a resol type phenol resin. 13. The electrophotographic photosensitive member according to claim 12, wherein the resol-type phenol resin is a resin synthesized by using ammonia or an amine compound. 14. The electrophotographic photosensitive member according to claim 13, wherein the resol-type phenol resin is a resin synthesized by using an amine compound. 15. The electrophotographic photosensitive member according to claim 4, wherein the curable resin is a thermosetting resin that is cured by heat. 16. The surface of the photoconductor is charged by applying only a DC voltage Vdc (V) to the photoconductor from the primary charging member used for the primary charging means, and a DC voltage Vdc (applied to the primary charging member is applied. 3. The electrophotographic photosensitive member according to claim 1, wherein the relational expression between V) and the photoconductor dark potential Vd (V) satisfies the following formula (3). | Vdc | − | Vd | ≦ | Vth / 2 | Formula (3) where Vth (discharge start voltage) = (7737.7 × D) ^1/2 +
312 + 6.2 × D D = L (photosensitive member film thickness μm) / K (photosensitive layer relative dielectric constant) 17. A peak-to-peak voltage Vpp (V) of an alternating voltage when an alternating voltage Vac (V) is superimposed on a DC voltage Vdc (V) on the photoconductor from a primary charging member used for the primary charging means. ) Satisfies the following formula (4): Vpp <2 × Vth formula (4) Further, the applied voltage Vdc (V) to the primary charging member, Vpp
The electrophotographic photosensitive member according to claim 1 or 2, wherein the relationship between (V) and the photoconductor dark potential Vd (V) satisfies the following formulas (3) and (5). | Vdc | − | Vd | ≦ | Vth / 2 | Formula (3) | Vd |> | Vpp / 2 | + | Vdc | − | Vth | Formula (5) 18. The electrophotographic photosensitive member according to claim 1, further comprising means for supplying charged conductive particles used for the primary charging means. 19. The charging member according to claim 1, wherein the electrically conductive charged particle supplying means used for the primary charging means directly coats the charging member.
The electrophotographic photosensitive member according to 1. 20. The charged particle supplying means used for the primary charging means directly coats the electrophotographic photosensitive member.
The electrophotographic photosensitive member according to 1. 21. The electrophotographic photosensitive member according to claim 1, wherein the conductive particles, which are the charged particles used for the primary charging means, have a volume resistivity of 1 × 10 ¹⁰ Ω · cm or less. 22. The particle size of the conductive particles used for the primary charging means is 10 nm or more and 1 pixel or less.
Or the electrophotographic photosensitive member according to item 2. 23. The electrophotographic photosensitive member according to claim 1, wherein the charging member used for the primary charging unit rotates in a counter direction with respect to the electrophotographic photosensitive member. 24. The electrophotographic photosensitive member according to claim 1, wherein the primary charging unit is made of an elastic foam. 25. A charged particle containing a conductive particle having a particle diameter of 10 μm to 10 nm as a main component and a surface having conductivity and elasticity, and a charged particle carrier for supporting the charged particle, The charged particles have a charging means for contacting the electrophotographic photoreceptor and charging the surface of the electrophotographic photoreceptor, and the resistance of the particles carried on the carrier is 10 ¹² to 10 ⁻¹ Ω · cm, The amount of particles carried is 0.1 mg / cm ^{2 to} 50 mg
/ Cm ² , and at least one of the charging means, the developing means and the cleaning means is integrated by directly injecting an electric charge into the surface of the photoconductor by applying a voltage to the photoconductor from the primary charging member. In the process cartridge which is supported by and is detachable from the main body of the electrophotographic apparatus,
The electrophotographic photoreceptor has at least a photosensitive layer and a charge injection layer on a conductive support, and the value of the oxidation potential (Eox) of the charge transport material used for the photosensitive layer satisfies the following formula (1). Characteristic process cartridge. 0.60 (V) ≦ Eox <0.80 (V) Formula (1) 26. The process cartridge according to claim 25, wherein the oxidation potential (Eox) of the charge transport material used for the photosensitive layer satisfies the following expression (2). 0.60 (V) ≦ Eox ≦ 0.76 (V) Formula (2) 27. The process cartridge according to claim 25, wherein the charge injection layer contains conductive particles and a binder resin. 28. The process cartridge according to claim 27, wherein the binder resin used for the charge injection layer is a curable resin. 29. The process cartridge according to claim 27, wherein the conductive particles used for the charge injection layer are metal or metal oxide particles. 30. The process cartridge according to claim 25, wherein the charge injection layer contains at least one of a fluorine atom-containing compound and a siloxane compound. 31. The process cartridge according to claim 25 or 26, wherein the charge injection layer contains lubricating particles. 32. The process cartridge according to claim 31, wherein the lubricating particles are at least one of fluorine atom-containing resin particles, silicone particles, silicon particles, and alumina particles. 33. The process cartridge according to claim 30, wherein the fluorine atom-containing compound is selected from the group consisting of a fluorine-containing silane coupling agent, a fluorine-modified silicone oil and a fluorine-based surfactant. 34. The siloxane compound is represented by the general formula (1):
31. The process cartridge according to claim 30, which is a siloxane compound represented by: [Chemical 2] (In the formula, A is a hydrogen atom or a methyl group, and the proportion of hydrogen atoms in all A is in the range of 0.1 to 50%,
(n is a positive integer of 0 or more) 35. The process cartridge according to claim 28, wherein the curable resin is at least one of a phenol resin, an acrylic resin, an epoxy resin, and a siloxane resin. 36. The process cartridge according to claim 35, wherein the phenol resin is a resol type phenol resin. 37. The process cartridge according to claim 36, wherein the resol-type phenol resin is a resin synthesized using ammonia and an amine compound. 38. The process cartridge according to claim 37, wherein the resol-type phenol resin is a resin synthesized by using an amine compound. 39. The process cartridge according to claim 28, wherein the curable resin is a thermosetting resin that is cured by heat. 40. The surface of the photoconductor is charged by applying only the DC voltage Vdc (V) to the photoconductor from the primary charging member used for the primary charging means, and the DC voltage Vdc (applied to the primary charging member is applied. 27. The process cartridge according to claim 25, wherein the relational expression between V) and the photoconductor dark potential Vd (V) satisfies the following expression (3). | Vdc | − | Vd | ≦ | Vth / 2 | Formula (3) where Vth (discharge start voltage) = (7737.7 × D) ^1/2 +
312 + 6.2 × D D = L (photosensitive member film thickness μm) / K (photosensitive layer relative dielectric constant) 41. A peak-to-peak voltage Vpp (V) of an alternating voltage when an alternating voltage Vac (V) is superimposed on a DC voltage Vdc (V) on the photoconductor from a primary charging member used for the primary charging means. ) Satisfies the following formula (4): Vpp <2 × Vth formula (4) Further, the applied voltage Vdc (V) to the primary charging member, Vpp
27. The relationship between (V) and the photoconductor dark potential Vd (V) satisfies the following expressions (3) and (5).
The process cartridge described in 1. | Vdc | − | Vd | ≦ | Vth / 2 | Formula (3) | Vd |> | Vpp / 2 | + | Vdc | − | Vth | Formula (5) 42. The process cartridge according to claim 25 or 26, further comprising means for supplying charged conductive particles used for the primary charging means. 43. The process cartridge according to claim 25 or 26, wherein the electrically conductive charged particle supplying means used for the primary charging means directly coats the charging member. 44. The process cartridge according to claim 25 or 26, wherein the charged particle supplying means used for the primary charging means directly coats the electrophotographic photosensitive member. 45. The process cartridge according to claim 25 or 26, wherein the conductive particles, which are the charged particles used for the primary charging means, have a volume resistivity of 1 × 10 ¹⁰ Ω · cm or less. 46. The particle size of the conductive particles used for the primary charging means is 10 nm or more and one pixel or less.
The process cartridge according to 5 or 26. 47. The process cartridge according to claim 25, wherein the charging member used for the primary charging means rotates in a counter direction with respect to the electrophotographic photosensitive member. 48. The process cartridge according to claim 25 or 26, wherein the primary charging means is made of an elastic foam. 49. When the charged particle supplying means stores charged particles in a developing means together with a developer, transfers the charged particles onto the photoconductor, and is transferred to a recording medium, a part of the photoconductor is not transferred and is exposed. The process cartridge according to claim 42, wherein the process cartridge remains on the body and is supplied to the charging means. 50. The process cartridge according to claim 25, wherein a cleaning unit is not provided between the transfer process and the primary charging process. 51. The process cartridge according to claim 25, wherein the charged particles are positively charged. 52. The process cartridge according to claim 25, wherein the charged conductive particles are positively charged with respect to the iron powder carrier. 53. 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. 50. The process cartridge according to claim 49, wherein in the charging unit supplied to the charging device, the conductive particles are positively charged in the developing device. 54. 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 carrier for supporting the charged particle, The charged particles have a charging means for contacting the electrophotographic photosensitive member and charging the surface of the electrophotographic photosensitive member, and the resistance of the particles carried on the carrier is 10 ¹² to 10 ⁻¹ Ω · cm, The amount of particles carried is 0.1 mg / cm ^{2 to} 50 mg
In the electrophotographic apparatus is a / cm ^2, at least a photosensitive layer and a charge injection layer electrophotographic photoreceptor is on the electrically conductive substrate and the oxidation potential of the charge transport material used for the photosensitive layer (Eo
An electrophotographic apparatus, wherein the value of x) satisfies the following expression (1). 0.60 (V) ≦ Eox <0.80 (V) Formula (1) 55. The electrophotographic apparatus according to claim 54, wherein the value of the oxidation potential (Eox) of the charge transport material used for the photosensitive layer satisfies the following expression (2). 0.60 (V) ≦ Eox ≦ 0.76 (V) Formula (2) 56. The electrophotographic apparatus according to claim 54, wherein the charge injection layer contains conductive particles and a binder resin. 57. The electrophotographic apparatus according to claim 56, wherein the binder resin used for the charge injection layer is a curable resin. 58. The electrophotographic apparatus according to claim 56, wherein the conductive particles used for the charge injection layer are metal or metal oxide particles. 59. The electrophotographic apparatus according to claim 54, wherein the charge injection layer contains at least one of a fluorine atom-containing compound and a siloxane compound. 60. The electrophotographic apparatus according to claim 54, wherein the charge injection layer contains lubricating particles. 61. The electrophotographic apparatus according to claim 60, wherein the lubricating particles are at least one of fluorine atom-containing resin particles, silicone particles, silicon particles, and alumina particles. 62. The electrophotographic apparatus according to claim 59, wherein the fluorine atom-containing compound is selected from the group consisting of a fluorine-containing silane coupling agent, a fluorine-modified silicone oil, and a fluorine-based surfactant. 63. The siloxane compound is represented by the general formula (1):
60. The electrophotographic apparatus according to claim 59, which is a siloxane compound represented by: [Chemical 3] (In the formula, A is a hydrogen atom or a methyl group, and the proportion of hydrogen atoms in all A is in the range of 0.1 to 50%,
(n is a positive integer of 0 or more) 64. The electrophotographic apparatus according to claim 57, wherein the curable resin is at least one of a phenol resin, an acrylic resin, an epoxy resin, and a siloxane resin. 65. The electrophotographic apparatus according to claim 64, wherein the phenol resin is a resol type phenol resin. 66. The electrophotographic apparatus according to claim 65, wherein the resol-type phenol resin is a resin synthesized using ammonia or an amine compound. 67. The electrophotographic apparatus according to claim 66, wherein the resol-type phenol resin is a resin synthesized by using an amine compound. 68. The electrophotographic apparatus according to claim 57, wherein the curable resin is a thermosetting resin that is cured by heat. 69. The surface of the photoconductor is charged by applying only the DC voltage Vdc (V) to the photoconductor from the primary charging member used for the primary charging means, and the DC voltage Vdc (Vdc (Vdc) applied to the primary charging member is used. The electrophotographic apparatus according to claim 54 or 55, wherein a relational expression between V) and the photoconductor dark potential Vd (V) satisfies the following expression (3). | Vdc | − | Vd | ≦ | Vth / 2 | Formula (3) where Vth (discharge start voltage) = (7737.7 × D) ^1/2 +
312 + 6.2 × D D = L (photosensitive member film thickness μm) / K (photosensitive layer relative dielectric constant) 70. A peak-to-peak voltage Vpp (V) of the alternating voltage when the alternating voltage Vac (V) is superimposed on the DC voltage Vdc (V) on the photoconductor from the primary charging member used in the primary charging means. ) Satisfies the following formula (4): Vpp <2 × Vth formula (4) Further, the applied voltage Vdc (V) to the primary charging member, Vpp
56. The relationship between (V) and the photoconductor dark potential Vd (V) satisfies the following expressions (3) and (5).
The electrophotographic apparatus according to 1. | Vdc | − | Vd | ≦ | Vth / 2 | Formula (3) | Vd |> | Vpp / 2 | + | Vdc | − | Vth | Formula (5) 71. The electrophotographic apparatus according to claim 54, further comprising means for supplying charged conductive particles used for the primary charging means. 72. The electrophotographic apparatus according to claim 54 or 55, wherein the electrically conductive charged particle supplying means used for the primary charging means directly coats the charging member. 73. The electrophotographic apparatus according to claim 54, wherein the charged particle supplying means used for the primary charging means directly coats the electrophotographic photosensitive member. 74. The electrophotographic apparatus according to claim 54, wherein the conductive particles, which are the charged particles used for the primary charging means, have a volume resistivity of 1 × 10 ¹⁰ Ω · cm or less. 75. The conductive particles used for the primary charging means have a particle size of 10 nm or more and one pixel or less.
The electrophotographic apparatus according to 4 or 55. 76. The electrophotographic apparatus according to claim 54, wherein the charging member used for the primary charging means rotates in the counter direction with respect to the electrophotographic photosensitive member. 77. The electrophotographic apparatus according to claim 54 or 55, wherein the primary charging means is composed of an elastic foam. 78. When the charged particle supplying means stores charged particles in a developing means together with a developer, transfers the charged particles onto the photoconductor, and is transferred onto a recording medium, a part of the photoconductor is not transferred to the photosensitive body. 72. The electrophotographic apparatus according to claim 71, wherein the electrophotographic apparatus remains on the body and is supplied to the charging means. 79. The electrophotographic apparatus according to claim 54, wherein a cleaning unit is not provided between the transfer process and the primary charging process. 80. The electrophotographic apparatus according to claim 54, wherein the charged particles are positively charged. 81. The electrophotographic apparatus according to claim 54, wherein the charged conductive particles are positively charged with respect to the iron powder carrier. 82. When the conductive particles are stored in a developing unit together with a developer, transferred onto the photoconductor, and transferred to a recording medium, a part of the conductive particles remains on the photoconductor without being transferred. 79. The electrophotographic apparatus according to claim 78, wherein in the charging unit supplied to the charging device, the conductive particles are positively charged in the developing device.