JP3192363B2 - Developer carrier, developing device, image forming apparatus, and process cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic method, in which an electrostatic latent image formed on an electrostatic latent image holding member such as an electrophotographic photosensitive member or an electrostatic recording dielectric is developed and visualized. 1. Field of the Invention The present invention relates to a developer carrying member used in such a process and a developing device, an image forming apparatus, and a process cartridge using the developer carrying member.

[0002]

2. Description of the Related Art Conventionally, for example, FIG. 6 shows a developing device which visualizes an electrostatic latent image formed on the surface of a photosensitive drum as an electrostatic latent image holding member with a magnetic toner as a one-component developer. The following devices are known. In FIG. 6, a developer container 53 holds a magnetic toner 54 as a one-component developer, and the friction between particles of the magnetic toner and the development sleeve 58 as a developer carrier and the magnetic toner particles. Due to the friction between the toner and the electrostatic latent image formed on the photosensitive drum 51, a charge having a polarity opposite to that of the developing reference potential is applied to the magnetic toner particles, and the magnetic toner is extremely deposited on the developing sleeve 58 by the magnetic blade 52. A thin coating is carried and carried to a developing area D formed by the photosensitive drum 51 and the developing sleeve 58. In the developing area D, the toner is carried by the action of a magnetic field by the magnet 55 fixed in the developing sleeve 58. There is known an image forming apparatus that visualizes an electrostatic latent image on a photosensitive drum 51 by flying a magnetic toner. A and B indicate the respective rotation directions of the developing sleeve 58 and the photosensitive drum 51, 59 indicates a developing bias means for applying a developing bias voltage during development, and 60 indicates a magnetic toner in the developer container 53. This is a stirring blade for stirring 54. However, when such a one-component developer is used, it is difficult to adjust the toner charge, and although various measures have been taken with the developer, the problems relating to the non-uniformity of the toner charge and the durability stability of the charge are as follows. Has not been completely solved.

In particular, while the developing sleeve is rotating repeatedly, the charge amount of the toner coated on the developing sleeve becomes too high due to the contact with the developing sleeve, and the toner is reflected by the mirror surface with the developing sleeve surface. As a result, it becomes immobile on the surface of the developing sleeve and does not move from the developing sleeve to the latent image on the electrostatic latent image holding member (drum), so-called charge-up phenomenon tends to occur particularly under low humidity. When such a charge-up phenomenon occurs,
Since the toner in the upper layer is hardly charged and the development amount of the toner is reduced, problems such as thinning of a line image and low image density of a solid image occur. Furthermore, the toner layer formation state of the image area (toner consuming section) and the non-image area change, and the charging state changes. For example, the position where a solid image having a high image density is developed is located next to the developing sleeve. When the halftone image is developed at the developing position when the image is rotated, a so-called sleeve ghost phenomenon that a trace of a solid image appears on the image is likely to occur.

In recent years, in order to further improve the image quality of electrophotography, toners have been reduced in particle size and particles. For example, in order to improve the resolving power and sharpness and faithfully reproduce a latent image, a toner having a weight average particle diameter of about 6 to 9 μm is generally used. Further, there is a tendency that the fixing temperature of the toner is lowered for the purpose of shortening the first copy time and saving power. In such a situation, the toner is more likely to electrostatically adhere to the developing sleeve, and the external force of physical force causes contamination of the developing sleeve surface and fusion of the toner. ing.

As a method for solving such a phenomenon, a developing sleeve in which a coating layer in which a solid lubricant and a conductive fine powder such as carbon are dispersed in a resin is provided on a metal substrate is used in a developing device. A method has been proposed. It is recognized that the use of this method greatly reduces the above-mentioned phenomenon. However, in this method, since the shape of the surface of the developing sleeve becomes non-uniform, uniform charging is still insufficient, and there is also a problem in durability such as embrittlement of the coating layer.

Japanese Patent Application Laid-Open No. 3-200986 proposes a developing sleeve in which a conductive coating layer in which a solid lubricant, a conductive fine powder such as carbon, and spherical particles are further dispersed in a resin is provided on a metal substrate. Have been. In this developing sleeve, the shape of the surface of the developing sleeve is made uniform, so that the charging becomes uniform and the wear resistance is improved. However, even in this developing sleeve, further improvement in durability performance such as improvement of abrasion resistance of the conductive coating layer and suppression of toner contamination and toner fusion when abrasion occurs is desired.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent the conductive coating layer on the surface of the developer carrier from being deteriorated due to repeated copying or durability, to have high durability and to achieve stable image quality. An object of the present invention is to provide a developer carrier obtained, a developing device having the developer carrier, an image forming apparatus, and a process cartridge. An object of the present invention is to provide a developer carrier capable of stably obtaining a high-quality image without causing problems such as a decrease in density, a sleeve ghost and fog over a long period of time even under different environmental conditions. Another object of the present invention is to provide a developing device, an image forming apparatus, and a process cartridge having the developer carrier. SUMMARY OF THE INVENTION An object of the present invention is to provide a developer carrier capable of suppressing non-uniform charging of toner on the surface of the developer carrier, which appears when a toner having a small particle diameter is used, and giving a proper charge amount to the toner. Another object of the present invention is to provide a developing device, an image forming apparatus, and a process cartridge having the developer carrier.

[0008]

The above object is achieved by the present invention described below. That is, the present invention provides, in a developer carrier having at least a substrate and a conductive coating layer covering the substrate, a binder resin in the conductive coating layer and a number average dispersed in the binder resin. A developer carrying member containing at least conductive spherical particles having a particle diameter of 0.3 to 30 μm and a true density of 3 g / cm ³ or less, a developing device having the developer carrying member, an image forming apparatus, and It is a process cartridge.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The developer carrier of the present invention can be provided with a specific conductive coating layer on the surface of the developer carrier, whereby the durability can be remarkably improved as compared with those conventionally used. Deterioration such as abrasion of the conductive coating layer on the surface of the developer carrier and toner contamination due to repeated copying or durability is unlikely to occur, so that high-quality images that are unlikely to cause image density reduction, ghosting and fog deterioration can be produced for a long time. Can be provided.

Hereinafter, the present invention will be described in detail. First, the conductive spherical particles used for the conductive coating layer coated on the surface of the substrate constituting the developer carrier of the present invention will be described. The conductive spherical particles used in the present invention have a number average particle diameter of 0.3 to 30 μm and a true density of 3 g / cm ³ or less. By adding such conductive spherical particles, the surface of the conductive coating layer of the developer carrying member of the present invention can be maintained at a uniform surface roughness. The change in the surface roughness of the coating layer is small, and the occurrence of toner contamination and toner fusion on the developer carrying member becomes difficult.

The number average particle diameter of the conductive spherical particles used in the present invention is 0.3 to 30 μm, preferably 2 to 20 μm.
Is better. Number average particle size of conductive spherical particles is 0.3
When the thickness is less than μm, the effect of imparting uniform surface roughness to the surface of the conductive coating layer is small, and toner charge-up, toner contamination and toner fusion due to abrasion of the conductive coating layer occur, resulting in an obtained image. It is not preferable because the deterioration due to the sleeve ghost and the decrease in image density are apt to occur. When the number average particle diameter exceeds 30 μm, the surface roughness of the conductive coating layer becomes too large, and the toner is not sufficiently charged. This is not preferable because it is difficult to perform the process and the mechanical strength of the conductive coating layer is reduced.

The true density of the conductive spherical particles used in the present invention is 3 g / cm ³ or less, preferably 2.7 g / cm ^3.
m ³ or less, more preferably 0.9 to 2.5 g / cm ³ . That is, the true density of the conductive spherical particles is 3 g /
When the average particle size exceeds ³ cm, the dispersibility of the spherical particles in the conductive coating layer becomes insufficient, so that it becomes difficult to impart uniform roughness to the coating layer surface, and uniform charging of the toner and the formation of the coating layer. The strength is insufficient, which is not preferable.

The term “spherical” in the conductive spherical particles means that the ratio of the major axis / minor axis is about 1.0 to 1.5, and in the present invention, the ratio of the major axis / minor axis is preferably It is preferable to use particles of 1.0 to 1.2, particularly preferably spherical particles. When the ratio of the major axis / minor axis of the conductive spherical particles exceeds 1.5, the dispersibility of the conductive spherical particles in the conductive coating layer decreases and the roughness of the surface of the conductive coating layer becomes uneven. This is not preferable in terms of uniform charging of the toner and strength of the conductive coating layer.

In the present invention, the conductivity of the conductive spherical particles refers to those having a volume resistivity of 10 ⁶ Ω · cm or less, and preferably a volume resistivity of 10 ³ to 10 ^-6 Ω · cm.
Using particles. The volume resistivity of the conductive spherical particles is 10
If it exceeds ⁶ Ω · cm, the toner is likely to be contaminated or fused with the spherical particles exposed on the surface of the conductive coating layer due to abrasion as nuclei.

As a method for obtaining the conductive spherical particles used in the present invention, the following methods are preferable, but are not necessarily limited thereto. As a method of obtaining particularly preferred conductive spherical particles used in the present invention,
For example, there is a method in which resin-based spherical particles or mesocarbon microbeads are carbonized and / or graphitized by firing to obtain low-concentration and good-conductive spherical carbon particles. Examples of the resin used for the resin-based spherical particles include phenol resin, naphthalene resin, furan resin, xylene resin, divinylbenzene polymer, styrene-divinylbenzene copolymer, and polyacrylonitrile. In addition, mesocarbon microbeads can be usually produced by washing a spherical crystal produced in the process of heating and firing a medium pitch with a large amount of a solvent such as tar, medium oil, and quinoline.

A more preferable method for obtaining conductive spherical particles is to use a mechanospheric surface such as a phenol resin, a naphthalene resin, a furan resin, a xylene resin, a divinylbenzene polymer, a styrene-divinylbenzene copolymer, or a polyacrylonitrile. There is a method in which a bulk mesophase pitch is coated by a chemical method, and the coated particles are heat-treated in an oxidizing atmosphere and then fired to be carbonized and / or graphitized to obtain conductive spherical carbon particles.

In any of the conductive spherical carbon particles obtained by the above-mentioned method, the conductivity of the spherical carbon particles obtained by changing the firing conditions can be controlled to some extent. Is preferably used. Further, in some cases, the spherical carbon particles obtained by the above-mentioned method may include conductive metal and / or conductive carbon particles in a range where the true density of the conductive spherical particles does not exceed ³ g / cm ³ in order to further increase the conductivity. Alternatively, metal oxide plating may be performed.

As another method for obtaining the conductive spherical particles used in the present invention, there is a method in which conductive fine particles smaller than the particle diameter of the core particles are mixed with the core particles composed of spherical resin particles at an appropriate mixing ratio. After the conductive fine particles are uniformly attached around the core particles by the action of van der Waals force and electrostatic force by mixing, for example, due to a local temperature rise caused by applying a mechanical impact force, The method includes softening the surface of the core particles, forming conductive fine particles on the surface of the core particles, and obtaining conductive resin-treated spherical resin particles.

As the core particles, it is preferable to use spherical resin particles made of an organic compound and having a low true density. Examples of the resin include PMMA, acrylic resin, and the like.
Polybutadiene resin, polystyrene resin, polyethylene, polypropylene, polybutadiene, or a copolymer thereof, benzoguanamine resin, phenol resin, polyamide resin, nylon, fluorine resin, silicone resin, epoxy resin, and polyester resin are exemplified.
As conductive fine particles (small particles) used when forming a film on the surface of the core particles (base particles), in order to uniformly provide a conductive fine particle coating, the particle size of the small particles is the same as that of the base particles. It is preferable to use those having 1/8 or less.

Still another method for obtaining the conductive spherical particles used in the present invention is to uniformly disperse the conductive fine particles in the spherical resin particles, thereby obtaining the conductive spherical particles in which the conductive fine particles are dispersed. There is a method of obtaining. As a method of uniformly dispersing the conductive fine particles in the spherical resin particles, for example, after kneading the binder resin and the conductive fine particles to disperse the conductive fine particles, solidify by cooling, and pulverize to a predetermined particle size A method of obtaining conductive spherical particles by mechanical and thermal treatments to obtain conductive spherical particles; or adding a polymerization initiator, conductive fine particles and other additives to a polymerizable monomer, and uniformly dispersing with a dispersing machine. The dispersed monomer composition is suspended in an aqueous phase containing a dispersion stabilizer so as to have a predetermined particle size by a stirrer and polymerized to obtain spherical particles in which conductive fine particles are dispersed. Method.

In the conductive spherical particles in which the conductive fine particles obtained by these methods are dispersed, the conductive spherical particles are mechanically mixed with the conductive fine particles having a particle diameter smaller than the above-mentioned core particles at an appropriate mixing ratio. After the conductive fine particles are uniformly attached around the conductive spherical particles by the action of van der Waals force and electrostatic force, for example, the conductive spherical particles The surface may be softened, conductive fine particles may be formed on the surface, and the conductivity may be further increased before use.

It is preferable to disperse the lubricating particles in the conductive coating layer constituting the developer carrier of the present invention in combination with the conductive spherical particles since the effect of the present invention is further promoted. As the lubricating particles, for example, graphite,
Particles composed of fatty acid metal salts such as molybdenum disulfide, boron nitride, mica, graphite fluoride, silver-niobium selenide, calcium chloride-graphite, talc and zinc stearate, among which graphite particles,
It is particularly preferably used because the conductivity of the conductive coating layer is not impaired when used in combination with the conductive spherical particles.

The lubricating particles preferably have a number average particle size of about 0.2 to 20 μm, more preferably 1 to 15 μm.
m. When the number average particle size of the lubricating particles is less than 0.2 μm, it is difficult to obtain sufficient lubricity, which is not preferable. When the number average particle size exceeds 20 μm, the surface roughness of the conductive coating layer is reduced. This is not preferable in terms of uniform charging of the toner and strength of the coating layer.

The conductive coating layer constituting the developer carrier of the present invention is formed by dispersing the conductive spherical particles and lubricating particles as described above in a binder resin. Examples of the binder resin material to be used include, for example, a styrene resin, a vinyl resin, a polyether sulfone resin,
Thermoplastic resins such as polycarbonate resin, polyphenylene oxide resin, polyamide resin, fluorine resin, cellulose resin and acrylic resin; epoxy resin, polyester resin, alkyd resin, phenol resin, melamine resin, polyurethane resin, urea resin, silicone resin And a heat or light curable resin such as a polyimide resin. Among them, those having release properties such as silicone resin and fluorine resin, or polyether sulfone resin, polycarbonate resin, polyphenylene oxide resin, polyamide resin, phenol resin, polyester resin, polyurethane resin, styrene resin and acrylic resin Those having excellent mechanical properties such as resins are more preferable.

In the present invention, the volume resistivity of the conductive coating layer of the developer carrying member is preferably 10 ³ Ω · cm or less, more preferably 10 ³ to 10 ^-2 Ω · cm. If the volume resistance of the conductive coating layer exceeds 10 ³ Ω · cm, toner charge-up is likely to occur,
It tends to cause ghost deterioration and density reduction. In the present invention, in order to adjust the volume resistance of the conductive coating layer, other conductive fine particles may be dispersed and contained in the conductive coating layer in combination with the above-mentioned conductive spherical particles. The conductive fine particles preferably have a number average particle size of 1 μm or less, more preferably 0.01 to 0.8 μm. When the number average particle diameter of the conductive fine particles dispersed and contained in the conductive coating layer in combination with the conductive spherical particles exceeds 1 μm, the volume resistance of the conductive coating layer becomes difficult to control low, and the toner The charge-up phenomenon easily occurs.

The conductive fine particles usable in the present invention include, for example, carbon blacks such as furnace black, lamp black, thermal black, acetylene black and channel black; titanium oxide, tin oxide, zinc oxide, molybdenum oxide; Metal oxides such as potassium titanate, antimony oxide and indium oxide;
Metals such as aluminum, copper, silver and nickel; inorganic fillers such as graphite, conductive metal fibers and conductive carbon fibers.

Next, the structure of the developer carrier of the present invention will be described. The developer carrier of the present invention is mainly composed of a metal cylindrical tube as a substrate and a conductive coating layer surrounding and surrounding the metal cylindrical tube. As the metal cylindrical tube, mainly stainless steel and aluminum are preferably used. The composition ratio of each component constituting the conductive coating layer will be described below, but these are particularly preferable ranges in the present invention.

The content of the conductive spherical particles dispersed in the conductive coating layer is preferably 2 to 120 parts by weight, more preferably 2 to 8 parts by weight, based on 100 parts by weight of the binder resin.
Particularly preferred results are obtained in the range of 0 parts by weight. When the content of the conductive spherical particles is less than 2 parts by weight, the effect of adding the conductive spherical particles is small, and when it exceeds 120 parts by weight, the chargeability of the toner may be too low.

When the lubricating particles are used in combination with the conductive spherical particles in the conductive coating layer, the content of the lubricating particles is preferably 5 to 120 parts by weight with respect to 100 parts by weight of the binder resin. Particularly in the range of 10 to 100 parts by weight gives particularly preferable results. When the content of the lubricating particles exceeds 120 parts by weight, a decrease in the film strength and a decrease in the charge amount of the toner are recognized. When the content is less than 5 parts by weight, 7 μm
When the toner having the following small particle diameter is used for a long time, the toner tends to be easily contaminated on the surface of the conductive coating layer.

When the conductive fine particles are dispersed and contained in the conductive coating layer in combination with the conductive spherical particles,
m or less of the conductive fine particles, the binder resin 10
Particularly preferable results are obtained when it is used in an amount of preferably 40 parts by weight or less, more preferably 2 to 35 parts by weight based on 0 parts by weight. That is, the content of the conductive fine particles is 40
If the amount is more than 10 parts by weight, a decrease in the coating strength and a decrease in the charge amount of the toner are not preferred.

In the present invention, as the roughness of the surface of the conductive coating layer, the center line average roughness (hereinafter referred to as “Ra”).
Is preferably in the range of 0.2 to 4.5 μm, and more preferably in the range of 0.4 to 3.5 μm. If the Ra on the surface of the conductive coating layer is less than 0.2 μm, the toner transportability may decrease, and a sufficient image density may not be obtained.
Exceeds 4.5 μm, the toner transport amount becomes too large, and the toner cannot be sufficiently charged, which is not preferable.

The layer thickness of the conductive coating layer having the above structure is preferably 25 μm or less, more preferably 20 μm or less.
Hereinafter, the thickness is more preferably 4 to 20 μm in order to obtain a uniform layer thickness, but is not particularly limited to this layer thickness. The thickness of these layers depends on the material used for the conductive coating layer, but is 4,000 to 20,000,
It can be obtained by setting it to about 00 mg / m ² .

Next, a description will be given of a developing device, an image forming apparatus, and a process cartridge of the present invention in which the above-described developer carrier of the present invention is incorporated. FIG. 1 is a schematic view of a developing device according to an embodiment having a developer carrier of the present invention. In FIG. 1, an electrostatic latent image holder for holding an electrostatic latent image formed by a known process, for example, an electrophotographic photosensitive drum 1 is rotated in the direction of arrow B. The developing sleeve 8 as a developer carrying member carries the one-component developer 4 having the magnetic toner supplied by the hopper 3 as the developer container, and rotates in the direction of arrow A, so that the developing sleeve 8 is exposed to light. The developer 4 is transported to a development area D where the drum 1 faces. As shown in FIG.
In the developing sleeve 8, there is disposed a magnet roller 5 to which a magnet is inscribed in order to magnetically attract and hold the developer 4 on the developing sleeve 8. The developing sleeve 8 used in the developing device of the present invention has a conductive coating layer 7 coated on a metal cylindrical tube 6 as a base. A stirring blade 10 for stirring the developer 4 is provided in the hopper 3. Reference numeral 12 denotes a gap indicating that the developing sleeve 8 and the magnet roller 5 are in a non-contact state.

The developer 4 obtains a triboelectric charge capable of developing the electrostatic latent image on the photosensitive drum 1 by friction between the magnetic toner and the conductive coating layer 7 on the developing sleeve 8. In the example of FIG. 1, in order to regulate the layer thickness of the developer 4 conveyed to the developing area D, the magnetic regulating blade 2 made of a ferromagnetic metal as a developer layer thickness regulating member is moved from the surface of the developing sleeve 8. It is suspended from the hopper 3 so as to face the developing sleeve 8 with a gap width of about 50 to 500 μm. The line of magnetic force from the magnetic pole N1 of the magnet roller 5 is concentrated on the magnetic regulating blade 2, so that a thin layer of the developer 4 is formed on the developing sleeve 8. In the present invention, a non-magnetic blade can be used instead of the magnetic regulating blade 2. The thickness of the thin layer of the developer 4 thus formed on the developing sleeve 8 is preferably smaller than the minimum gap between the developing sleeve 8 and the photosensitive drum 1 in the developing area D.

It is particularly effective to incorporate the developer carrier of the present invention into a developing device of the type which develops an electrostatic latent image with a thin layer of the developer as described above, that is, a non-contact type developing device. In the developing region D, the developer carrier of the present invention is also applied to a developing device in which the thickness of the developer layer is equal to or greater than the minimum gap between the developing sleeve 8 and the photosensitive drum 1, that is, a contact type developing device. can do. To avoid complications,
In the following description, the non-contact type developing device as described above is taken as an example.

A developing bias voltage is applied to the developing sleeve 8 by a developing bias power supply 9 serving as a bias means in order to fly the one-component developer 4 having the magnetic toner carried on the developing sleeve 8. When a DC voltage is used as the developing bias voltage, a voltage having an intermediate value between the potential of the image portion of the electrostatic latent image (the region where the developer 4 is adhered and visualized) and the potential of the background portion is set to the developing sleeve 8. Is preferably applied. In order to increase the density of the developed image or improve the gradation, an alternating bias voltage may be applied to the developing sleeve 8 to form an oscillating electric field in which the direction is alternately reversed in the developing region D. In this case, it is preferable to apply to the developing sleeve 8 an alternating bias voltage in which a DC voltage component having a value intermediate between the potential of the developed image portion and the potential of the background portion is superimposed.

In the case of so-called regular development, toner is attached to the high potential portion of the electrostatic latent image having a high potential portion and a low potential portion to visualize the toner, and the electrostatic latent image is charged to a polarity opposite to that of the electrostatic latent image. Use toner. In the case of so-called reversal development, a toner charged to the same polarity as that of the electrostatic latent image is used in the case of so-called reversal development in which toner is attached to a low potential portion of an electrostatic latent image having a high potential portion and a low potential portion to visualize the toner. I do. High potential and low potential are expressed by absolute values. In any of these cases, the developer 4 is charged at least by friction with the developing sleeve 8.

FIG. 2 is a schematic diagram showing a configuration of another embodiment of the developing device of the present invention, and FIG. 3 is a schematic diagram showing a configuration of still another embodiment of the developing device of the present invention. In the developing device shown in FIGS. 2 and 3, urethane rubber, a urethane rubber, is used as a developer layer thickness regulating member for regulating the layer thickness of the developer 4 on the developing sleeve 8.
An elastic regulating blade 11 made of an elastic plate made of a material having rubber elasticity such as silicone rubber or a material having metallic elasticity such as phosphor bronze or stainless steel is used. In the developing device shown in FIG. 8
3 is characterized in that the elastic regulating blade 11 is pressed against the rotation direction of the developing sleeve 8 in the forward direction. In these developing devices, a thin layer of the developer is formed on the developing sleeve by elastically pressing the developer layer thickness regulating member against the developing sleeve 8 via the developer layer. FIG. 1 described above on the sleeve 8
A thinner developer layer can be formed than in the case of the cited example.

Other basic structures of the developing devices of FIGS. 2 and 3 are the same as those of the developing device shown in FIG. 1, and those having the same reference numerals indicate basically the same members. 1 to 3 schematically illustrate the developing device of the present invention, and show the shape of the developer container (hopper 3) and the stirring blade 1
It goes without saying that there are various forms in the presence or absence of 0 and the arrangement of the magnetic poles. Of course, these devices can also be used for development using a two-component developer containing a toner and a carrier.

An example of an image forming apparatus using the developing device of the present invention illustrated in FIG. 3 will be described with reference to FIG. First, contact (roller) as primary charging means
The surface of the photosensitive drum 101 serving as an electrostatic latent image holding member is charged to a negative polarity by the charging unit 119, and the laser light
A digital latent image is formed on the photosensitive drum 101 by the image scanning by 15. Next, a developing device having an elastic regulating blade 111 as a developer layer thickness regulating member and having a developing sleeve 108 as a developer carrying member in which a multipolar permanent magnet 105 is included,
The digital latent image is reversely developed by a one-component developer 104 having a magnetic toner in a hopper 103. As shown in FIG.
01 is grounded, and the developing sleeve 10
8 is supplied with an alternating bias, a pulse bias and / or a DC bias by a bias applying means 109. Next, when the recording material P is conveyed and arrives at the transfer section, the contact (roller) transfer means 113 as a transfer means is charged from the back surface (the surface opposite to the photosensitive drum side) of the recording material P by the voltage application means 114. As a result, the photosensitive drum 10
The developed image (toner image) formed on the surface of the recording material P is transferred onto the recording material P by the contact transfer unit 113. Next, the recording material P separated from the photosensitive drum 101 is transported to a heating / pressing roller fixing device 117 as a fixing unit, and the fixing device 117 performs a fixing process of the toner image on the recording material P. .

The one-component developer 104 remaining on the photosensitive drum 101 after the transfer process is removed by a cleaning blade 118.
It is removed by the cleaning means 118 having a. If the remaining one-component developer 104 is small, the cleaning step can be omitted. After the cleaning, the photosensitive drum 101 is neutralized if necessary by the erase exposure 116, and the above-described steps starting from the charging step by the contact (roller) charging means 119 as the primary charging means are repeated again.

In the above series of steps, the photosensitive drum (that is, the electrostatic latent image holding member) 101 has a photosensitive layer and a conductive substrate, and moves in the direction of the arrow. The non-magnetic cylindrical developing sleeve 108 serving as the developer carrier rotates so as to advance in the same direction as the surface of the photosensitive drum 101 in the developing area D. Inside the developing sleeve 108, a multi-pole permanent magnet (magnet roll) 105 as a magnetic field generating means is arranged so as not to rotate. The one-component developer 104 in the developer container 103 is applied and carried on the developing sleeve 108 and, for example, due to friction with the surface of the developing sleeve 108 and / or friction between the magnetic toners, for example, a negative triboelectric charge Is given. Further, the elastic regulating blade 111 is provided so as to elastically press the developing sleeve 108, and the thickness of the developer layer is reduced (30 μm to 300 μm).
The photosensitive drum 1 in the developing region D is regulated uniformly.
Then, a developer layer thinner than the gap between the developing sleeve and the developing sleeve is formed. By adjusting the rotation speed of the developing sleeve 108, the surface speed of the developing sleeve 108 is substantially equal to or close to the speed of the surface of the photosensitive drum 101. In the developing region D, an AC bias or a pulse bias may be applied to the developing sleeve 108 as a developing bias voltage by the bias applying unit 109. This AC bias is f 200 ~
4,000Hz, V _pp may if 500~3,000V.

Developer (magnetic toner) in development area D
The magnetic toner is transferred to the electrostatic latent image side by the electrostatic force on the surface of the photosensitive drum 101 and the action of a developing bias voltage such as an AC bias or a pulse bias.

Instead of the elastic regulating blade 111, a magnetic doctor blade such as iron can be used.
The primary charging means has been described using the charging roller 119 as the contact charging means as described above, but may be a contact charging means such as a charging blade or a charging brush, or a non-contact corona charging means. However, the contact charging means is preferable in that the generation of ozone due to charging is small. As the transfer means, the transfer roller 1 as described above is used.
Although the description has been made using the contact transfer means such as 13, a non-contact corona transfer means may be used. However, the contact transfer means is also preferable in that the generation of ozone due to transfer is small.

FIG. 5 shows a specific example of the process cartridge of the present invention. In the following description of the process cartridge, components having the same functions as the components of the image forming apparatus described with reference to FIG. 4 will be described using the same reference numerals as those in FIG. The process cartridge of the present invention
At least the developing means and the electrostatic latent image holding member are integrally formed into a cartridge, and are configured to be detachable from an image forming apparatus main body (for example, a copying machine, a laser beam printer, a facsimile machine).

In the embodiment shown in FIG.
0, drum-shaped electrostatic latent image holder (photosensitive drum) 101,
A process cartridge 150 in which a cleaning unit 118 having a cleaning blade 118a and a contact (roller) charging unit 119 as a primary charging unit are integrated is exemplified. In this embodiment, the developing means 120, a developing
One-component developer 104 having magnetic toner in sleeve 108, elasticity regulating blade 111 and developer container 103
It has the door, using a developer 104, a photosensitive drum 10 by the developing bias voltage from a bias applying means during development
A predetermined electric field is formed between the developing sleeve 1 and the developing sleeve 108, and the developing process is performed. The distance between the photosensitive drum 101 and the developing sleeve 108 is very important for suitably executing this developing step.

In the above description, the developing means 120, the electrostatic latent image holding member 101, the cleaning means 118, and the primary charging means 1
Although the embodiment in which the fourteen components are integrally formed into a cartridge has been described, in the present invention, at least two components of the developing means and the electrostatic latent image holding member are integrally formed in a cartridge. And three components of a developing unit, an electrostatic latent image holder and a cleaning unit, and a developing unit, an electrostatic latent image holder and a primary charging unit.
It is also possible to integrally form a cartridge by adding one component or another component.

Next, in the present invention, a developer (toner) used for obtaining a visible image from an electrostatic latent image will be described. The toner contained in the developer is roughly classified into a dry toner and a wet toner. However, the dry toner is mainly used at present because the problem of solvent evaporation is large.
The toner is mainly a fine powder obtained by melt-kneading materials such as a binder resin, a release agent, a charge control agent, and a colorant, cooling and solidifying the melt, pulverizing, and then classifying to obtain a uniform particle size distribution. It is.

Examples of the binder resin used in the toner include a homopolymer of styrene such as styrene, α-methylstyrene and p-chlorostyrene and a substituted product thereof; a styrene-propylene copolymer and a styrene-vinyltoluene copolymer. Polymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl copolymer, styrene-methyl methacrylate copolymer, styrene- Ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer Coal, styrene-isoprene copolymer, styrene Styrene-based copolymers such as styrene-maleic acid copolymer and styrene-maleic acid ester copolymer; polymethyl methacrylate; polybutyl methacrylate; polyvinyl acetate; polyethylene; polypropylene; polyvinyl butyral; Modified rosin; terpene resin; phenol resin; aliphatic or alicyclic hydrocarbon resin; aromatic petroleum resin; paraffin wax; carnauba wax can be used alone or in combination.

When the toner is used as a color toner (non-magnetic toner), a pigment can be contained in the toner as a colorant. Examples of the pigment include carbon black, nigrosine dye, lamp black, Sudan black SM, First Yellow G, and benzidine.
Yellow, Pigment Yellow, India First
Orange, Irgazine Red, Paranitroaniline
Red, Toluidine Red, Carmin FB, Permanent Bordeaux FRR, Pigment Orange R, Risor Red 2G, Rake Red C, Rhodamine F
B, rhodamine B lake, methyl violet B lake, phthalocyanine blue, pigment blue, brilliant green B, phthalocyanine green, oil yellow GG, pomelo first yellow CG
G, Kayaset Y963, Kayaset YG, Pomelo First Orange RR, Oil Scarlet, Orazol Brown B, Pomelo First Scarlet C
G and oil pink OP, which can be appropriately selected and used from these.

When the toner is used as a magnetic toner, a magnetic powder is contained in the toner. As such a magnetic powder, a substance which is magnetized in a magnetic field is used. Examples of the magnetic powder include powders of ferromagnetic metals such as iron, cobalt, and nickel; and alloys and compounds such as magnetite, hetamine, and ferrite. The content of these magnetic powders is 15 to 7 with respect to the toner weight.
It is preferred to be about 0% by weight. Various release agents may be added to the toner and contained. Examples of such release agents include polyfluoroethylene, fluororesin, fluorocarbon oil, silicone oil, low molecular weight polyethylene, low molecular weight polypropylene, and various types of release agents. Waxes. Further, if necessary, various charge control agents may be added in order to facilitate positive or negative charging.

In the present invention, the non-magnetic toner may be mixed with a carrier and used as a two-component developer.
Alternatively, it can be used as a non-magnetic one-component developer without being mixed with a carrier. Further, in the present invention,
The magnetic toner can be used as a one-component developer.

The method for measuring physical properties according to the present invention will be described below. (1) Measurement of Center Line Average Roughness (Ra) Based on the surface roughness of JIS B0601, it was measured at three points in the axial direction × two points in the circumferential direction = 6 points using a surf coder SE-3300 manufactured by Kosaka Laboratory. And took the average.

(2) Measurement of Volume Resistance of Particles A granular sample was placed in an aluminum ring of 40 mmφ and 2500
It is press-molded with N, and the volume resistance value is measured with a resistivity meter Loresta AP or Hiresta IP (both manufactured by Mitsubishi Yuka) using a four-terminal probe. The measurement environment is 20-25.
C., 50 to 60% RH.

(3) Measurement of Volume Resistance of Coating Layer A conductive coating layer having a thickness of 7 to 20 μm was formed on a PET sheet having a thickness of 100 μm, and was subjected to ASTM standard (D-991).
-82) and Japan Rubber Association Standard SRIS (2301)
-1969), using a voltage drop type digital ohmmeter (manufactured by Kawaguchi Electric Works) provided with a four-terminal electrode for measuring the volume resistance of conductive rubber and plastic. The measurement environment is 20-25 ° C, 50-60% R
H.

(4) Measurement of True Density of Spherical Particles The true density of the conductive spherical particles used in the present invention was measured using a dry type densitometer Acupic 1330 (manufactured by Shimadzu Corporation). (5) Particle Size Measurement of Spherical Particles The particle number was measured using a Coulter LS-130 type particle size distribution meter (manufactured by Coulter, Inc.) of a laser diffraction type particle size distribution meter, and the number average particle size calculated from the number distribution was obtained.

(6) Measurement of Particle Size of Conductive Fine Particle The particle size of the conductive fine particle is measured using an electron microscope.
The photographing magnification is set at 60,000 times. If it is difficult, the photograph is photographed at a low magnification and then the photograph is enlarged and printed at 60,000 times. Measure the particle size of the primary particles on the photograph. At this time, the major axis and the minor axis are measured, and the average value is defined as the particle diameter. This is measured for 100 samples, and the 50% value is defined as the average particle size.

(7) Adhesion Weight of Conductive Coating Layer The weight of the entire developer carrier before and after the formation of the conductive coating layer on the developer carrier was measured using an electronic balance, and the weight difference was determined. The adhesion weight of the conductive coating layer was determined.

(8) Measurement of Toner Particle Diameter The toner was measured using a Coulter Counter Multisizer II (manufactured by Coulter Co., Ltd.), and the weight-based weight average diameter obtained from the volume distribution was determined. As described above, according to the present invention, the durability is improved as compared with the conventionally used developer carrier, and it is possible to maintain a state in which a good image can be provided for a long time. Thus, according to the present invention,
Highly durable developer carrier that does not cause deterioration such as abrasion of the conductive coating layer on the surface of the developer carrier due to repeated copying or durability and toner contamination. Image can be provided for a long time.

[0060]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the examples do not limit the present invention at all. Note that “%” and “part” in Examples and Comparative Examples
All parts are by weight unless otherwise specified. <Example 1> As the conductive spherical particles, a number average particle size of 10
100 parts of a spherical phenolic resin of 100 μm is uniformly coated with 14 parts by weight of a coal-based bulk mesophase pitch powder having a number average particle diameter of 3 μm or less using a raikai machine (automatic mortar, manufactured by Ishikawa Plant), and then under an oxidizing atmosphere. Spherical conductive carbon particles (conductive spherical particles A-1) obtained by graphitization by baking at 2,200 ° C. after the heat stabilization treatment were used. Table 1 shows the physical properties of the conductive spherical particles A-1. 200 parts of resol type phenol resin solution (containing 50% methanol) 45 parts of graphite having a number average particle diameter of 6.1 μm 5 parts of conductive carbon black 130 parts of isopropyl alcohol The above material is made of zirconia beads having a diameter of 1 mm as media particles. In addition, the mixture was dispersed in a sand mill for 2 hours, and zirconia beads were separated using a sieve to obtain a stock solution B-1.

To 380 parts of the stock solution of B-1 obtained above,
10 parts of conductive spherical particles A-1 were added, and the solid content concentration was 3
After adding isopropyl alcohol to 2%,
The dispersion was performed for 1 hour using glass beads having a diameter of 3 mm, and the glass beads were separated using a sieve to obtain a coating liquid. Using this coating solution, a conductive coating layer having a coating width of 216 mm is formed on an aluminum cylindrical tube having an outer diameter of 16 mm by a spray method, and then heated at 150 ° C. for 30 minutes in a hot-air drying furnace to form a conductive coating. The layer is cured and the developer carrier C-
1 was produced. The adhesion weight of the conductive coating layer after drying is 10
0 mg and the layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-1.

As the image forming apparatus shown in FIG. 4 having the developing device shown in FIG. 3 with the C-1 developer carrier, using a laser beam printer Laser Jet III Si (manufactured by Hewlett-Packard), a one-component developer was used. While supplying the developer, a durability evaluation test of the developer carrying member was performed. The following was used as the one-component developer.・ Styrene-acrylic resin 100 parts ・ Magnetite 80 parts ・ 3,5-di-tert-butylsalicylate chromium complex 2 parts ・ Low molecular weight polypropylene 4 parts Kneading, grinding and classification of the above materials by a general dry toner production method Was carried out to obtain a fine powder (toner particles) having a number average particle size of 6.9 μm. To 100 parts of the fine powder, 1.0 part of hydrophobic colloidal silica was externally added to obtain a magnetic toner, and the magnetic toner was used as a one-component developer. The image forming apparatus used in this embodiment has a process cartridge in which an electrostatic latent image holding member, a developing unit, a cleaning unit, and a primary charging unit are integrally formed as a cartridge. The configuration shown in FIG.

Example 2 As conductive spherical particles, 100 parts of a spherical phenol resin having a number average particle size of 4.8 μm were
Using a Raikai machine (automatic mortar, manufactured by Ishikawa Plant), 14 parts of a coal-based bulk mesophase pitch powder having a number average particle size of 1 μm or less is uniformly coated and subjected to a thermal stabilization treatment in an oxidizing atmosphere, followed by 2,200 ° C. Spherical conductive carbon particles obtained by graphitization by firing (conductive spherical particles A-
2) was used. Table 1 shows the physical properties of the conductive spherical particles A-2. A developer carrying member C-2 was prepared in the same manner as in Example 1 except that 25 parts of the conductive spherical particles A-2 were added to 380 parts of the stock solution of B-1 produced in Example 1. The adhesion weight of the conductive coating layer after drying was 105 mg, and the layer thickness was 8 μm.
Met. . Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-2. Using the C-2 developer carrier in the same image forming apparatus as in Example 1, a durability evaluation test was performed on the developer carrier while supplying a one-component developer in the same manner as in Example 1.

<Example 3> Coal-based bulk having a number average particle size of 4 μm or less as conductive spherical particles on 100 parts of a spherical phenol resin having a number average particle size of 26 μm using a raikai machine (automatic mortar, manufactured by Ishikawa Plant). Mesophase pitch powder 1
Four parts are uniformly coated, subjected to a thermal stabilization treatment in an oxidizing atmosphere, and then calcined at 2,200 ° C. to be graphitized to obtain spherical conductive carbon particles (conductive spherical particles A-).
3) was used. Table 1 shows the physical properties of the conductive spherical particles A-3. A developer carrying member C-3 was prepared in the same manner as in Example 1 except that 6 parts of the conductive spherical particles A-3 were added to 380 parts of the stock solution of B-1 produced in Example 1. The adhesion weight of the conductive coating layer after drying was 100 mg, and the layer thickness was 8 μm.
Met. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-3. Using the developer carrying member of C-3 in the same image forming apparatus as in Example 1, a durability evaluation test of the developer carrying member was performed while supplying a one-component developer in the same manner as in Example 1.

Example 4 As conductive spherical particles, 14 parts of a coal-based bulk mesophase pitch powder having a number average particle size of 3 μm or less were added to 100 parts of a spherical phenol resin having a number average particle size of 10 μm in the same manner as in Example 1. Spherical conductive carbon particles obtained by carbonizing by uniformly coating using a machine (automatic mortar, manufactured by Ishikawa Plant), performing heat stabilization treatment in an oxidizing atmosphere, and baking at 1,000 ° C. The conductive spherical particles A-4) were used. Table 1 shows the physical properties of the conductive spherical particles A-4. Stock solution 38 of B-1 produced in Example 1
A developer carrier C-4 was prepared in the same manner as in Example 1 except that 10 parts of the conductive spherical particles A-4 were added to 0 parts.
The adhesion weight of the conductive coating layer after drying was 95 mg, and the layer thickness was 8 μm. . Table 2 shows the physical properties of the conductive coating layer of this developer carrier C-4. Using the C-4 developer carrier in the same image forming apparatus as in Example 1, while supplying a one-component developer in the same manner as in Example 1, a durability evaluation test of the developer carrier was performed.

Example 5 As a conductive spherical particle, a spherical phenol resin having a number average particle size of 10.0 μm was subjected to thermal stabilization treatment in an oxidizing atmosphere, and then calcined at 2,200 ° C. to be graphitized. The obtained spherical conductive carbon particles (conductive spherical particles A-5) were used. Table 1 shows the physical properties of the conductive spherical particles A-5. B manufactured in Example 1
Developer-supporting member C- in the same manner as in Example 1 except that 10 parts of the conductive spherical particles A-5 were added to 380 parts of the stock solution of C-1
5 was produced. The adhesion weight of the conductive coating layer after drying is 10
0 mg and the layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-5. Using the C-5 developer carrier in the same image forming apparatus as in Example 1,
While supplying the one-component developer in the same manner as in Example 1, the durability evaluation test of the developer carrying member was performed.

Example 6 As a conductive spherical particle, a spherical phenol resin having a number average particle diameter of 10.3 μm was subjected to a thermal stabilization treatment in an oxidizing atmosphere and then calcined at 1,000 ° C. for carbonization. The obtained spherical conductive carbon particles (conductive spherical particles A-6) were used. Table 1 shows the physical properties of the conductive spherical particles A-6. B- produced in Example 1
A-6 was added to 380 parts of the stock solution of No. 1 as conductive spherical particles.
A developer carrying member C-6 was prepared in the same manner as in Example 1 except that 0 part was added. The adhesion weight of the conductive coating layer after drying was 95 mg, and the layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-6. C-6
Using the developer carrier of Example 1 in the same image forming apparatus as in Example 1, while supplying a one-component developer in the same manner as in Example 1,
A durability test was performed on the developer carrier.

Example 7 Spherical divinylbenzene polymer 1 having a number average particle size of 10.2 μm was used as conductive spherical particles.
To 00 parts, 14 parts by weight of petroleum-based bulk mesophase pitch powder having a number average particle diameter of 3 μm or less was uniformly coated using a Raikai machine (automatic mortar, manufactured by Ishikawa Plant), and after heat stabilizing treatment in an oxidizing atmosphere, Spherical conductive carbon particles (conductive spherical particles A-7) obtained by graphitization by baking at 2,000 ° C. were used. Table 1 shows the physical properties of the conductive spherical particles A-7. Stock solution 38 of B-1 produced in Example 1
A developer carrying member C-7 was prepared in the same manner as in Example 1 except that 10 parts of the conductive spherical particles A-7 were added to 0 parts.
The adhesion weight of the conductive coating layer after drying was 105 mg,
The layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-7. Using the C-7 developer carrier in the same image forming apparatus as in Example 1, a durability evaluation test was performed on the developer carrier while supplying a one-component developer in the same manner as in Example 1.

Example 8 As conductive spherical particles, 100 parts of the conductive spherical particles A-4 used in Example 4 were used.
Metal-coated carbon particles (conductive spherical particles A-8) plated with 100 parts of copper and silver were used. Table 1 shows the physical properties of the conductive spherical particles A-8. Stock solution 3 of B-1 produced in Example 1
A developer carrying member C-8 was prepared in the same manner as in Example 1 except that 10 parts of the conductive spherical particles A-8 were added to 80 parts. The adhesion weight of the conductive coating layer after drying was 110 mg, and the layer thickness was 9 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-8. Using the C-8 developer carrier in the same image forming apparatus as in Example 1, a durability evaluation test was performed on the developer carrier while supplying a one-component developer in the same manner as in Example 1.

<Example 9> As a conductive spherical particle, using a hybridizer (manufactured by Nara Machinery Co., Ltd.), the number average particle diameter was 1
Spherical conductive resin particles (conductive spherical particles A-9) obtained by coating 1.5 parts of 1.5 μm spherical PMMA particles with 5 parts of conductive carbon black were used. Table 1 shows the physical properties of the conductive spherical particles A-9. In the same manner as in Example 1 except that 10 parts of the conductive spherical particles A-9 were added to 380 parts of the stock solution of B-1 produced in Example 1,
A developer carrier C-9 was produced. The adhesion weight of the conductive coating layer after drying was 100 mg, and the layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-9. Using the C-9 developer carrier in the same image forming apparatus as in Example 1, while supplying a one-component developer in the same manner as in Example 1, a durability evaluation test of the developer carrier was performed.

Example 10 As a conductive spherical particle, a hybridizer (manufactured by Nara Machinery Co., Ltd.) was used to coat 100 parts of spherical PMMA particles having a number average particle diameter of 11.5 μm with 20 parts of conductive zinc oxide fine particles. The obtained resin particles (conductive spherical particles A-10) subjected to the conductive treatment were used. Table 1 shows the physical properties of the conductive spherical particles A-10. A developer carrying member C-10 was prepared in the same manner as in Example 1, except that 10 parts of the conductive spherical particles A-10 were added to 380 parts of the stock solution of B-1 produced in Example 1. The adhesion weight of the conductive coating layer after drying was 105 mg, and the layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-10. Using the C-10 developer carrier in the same image forming apparatus as in Example 1, a durability evaluation test of the developer carrier was performed while supplying a one-component developer in the same manner as in Example 1.

Example 11 Using a hybridizer (manufactured by Nara Machinery Co., Ltd.) as conductive spherical particles, 100 parts of spherical nylon particles having a number average particle size of 11.0 μm were added to graphite 18 having a number average particle size of 1 μm or less. Spherical conductive resin particles (conductive spherical particles A-11) obtained by coating the portions were used. Table 1 shows the physical properties of the conductive spherical particles A-11. A developer carrying member C-11 was produced in the same manner as in Example 1 except that 10 parts of the conductive spherical particles A-11 were added to 380 parts of the stock solution of B-1 produced in Example 1.
The adhesion weight of the conductive coating layer after drying was 100 mg,
The layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-11. Using the C-11 developer carrier in the same image forming apparatus as in Example 1, a durability evaluation test of the developer carrier was performed while supplying a one-component developer in the same manner as in Example 1.

Example 12 The following materials were used as conductive spherical particles, and kneading, pulverization and classification were performed to obtain conductive particles having a number average particle size of 15.6 μm. Then, a hybridizer (Nara Machinery Co., Ltd.) was used. Spherical resin particles (conductive spherical particles A) obtained by performing a sphering treatment using
-12) was used. Table 1 shows the physical properties of the conductive spherical particles A-12. 100 parts of styrene-dimethylaminoethyl methacrylate-divinylbenzene copolymer (copolymerization ratio: 90: 10: 0.05) 25 parts of conductive carbon black To 380 parts of the undiluted solution of B-1 produced in Example 1, A developer carrying member C-12 was prepared in the same manner as in Example 1 except that 10 parts of the conductive spherical particles A-12 were added. The adhesion weight of the conductive coating layer after drying was 95 mg, and the layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-12. Using the C-12 developer carrier in the same image forming apparatus as in Example 1, a durability evaluation test was performed on the developer carrier while supplying a one-component developer in the same manner as in Example 1.

Example 13 The following materials were used as the conductive spherical particles, and kneading, pulverization and classification were performed to obtain conductive particles having a number average particle size of 13.1 μm. Then, a hybridizer (Nara Machinery Co., Ltd.) was used. Spherical resin particles (conductive spherical particles A) obtained by performing a sphering treatment using
-13) was used. Table 1 shows the physical properties of the conductive spherical particles A-13. 100 parts of styrene-dimethylaminoethyl methacrylate-divinylbenzene copolymer (copolymerization ratio: 90: 10: 0.05) 50 parts of conductive titanium oxide 380 parts of the stock solution of B-1 produced in Example 1 A developer carrying member C-13 was prepared in the same manner as in Example 1, except that 10 parts of the conductive spherical particles A-13 were added. The adhesion weight of the conductive coating layer after drying was 100 mg, and the layer thickness was 8 μm.
Met. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-13. Example 1 Using a C-13 developer carrier
Using the same image forming apparatus as in Example 1, a durability evaluation test of the developer carrying member was performed while supplying a one-component developer in the same manner as in Example 1.

Example 14 The following materials were used as the conductive spherical particles, and kneading, pulverization and classification were performed to obtain conductive particles having a number average particle size of 10.5 μm. Spherical resin particles (conductive spherical particles A) obtained by performing a sphering treatment using
-14). Table 1 shows the physical properties of the conductive spherical particles A-14. 100 parts of styrene-dimethylaminoethyl methacrylate-divinylbenzene copolymer (copolymerization ratio: 90: 10: 0.05) 50 parts of silver fine particles 380 parts of the undiluted solution of B-1 produced in Example 1, A developer carrying member C-14 was prepared in the same manner as in Example 1 except that 10 parts of the spherical particles A-14 were added. The adhesion weight of the conductive coating layer after drying was 105 mg, and the layer thickness was 8 μm.
Met. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-14. Example 1 C-14 developer carrier
Using the same image forming apparatus as in Example 1, a durability evaluation test of the developer carrying member was performed while supplying a one-component developer in the same manner as in Example 1.

Example 15 200 parts of resole type phenol resin solution (containing 50% methanol) 20 parts of conductive carbon black 130 parts of isopropyl alcohol To the above materials, zirconia beads having a diameter of 1 mm were added as media particles, and the mixture was subjected to a sand mill. For 2 hours, and the zirconia beads were separated using a sieve to obtain a stock solution B-2.
In 380 parts of the stock solution of B-2, 10 conductive spherical particles A-1 were added.
Developer carrier C in the same manner as in Example 1 except that
-15 was produced. The adhesion weight of the conductive coating layer after drying was 100 mg, and the layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-15. C
Using the developer carrying member of No. -15 in the same image forming apparatus as in Example 1, a durability evaluation test of the developer carrying member was performed while supplying a one-component developer in the same manner as in Example 1.

<Example 16> 200 parts of PMMA resin solution (containing 50% of toluene) 45 parts of graphite having a number average particle diameter of 6.1 μm 5 parts of conductive carbon black 5 parts of toluene 130 parts of the above material were zirconia having a diameter of 1 mm. The beads were added as media particles, dispersed in a sand mill for 2 hours, and zirconia beads were separated using a sieve to obtain a stock solution B-3.
To 380 parts of the stock solution of B-3, 10 conductive spherical particles A-1 were added.
A developer carrying member C-16 was prepared in the same manner as in Example 1 except for adding a portion. The adhesion weight of the conductive coating layer after drying was 105 mg, and the layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-16.
Using the C-16 developer carrier in the same image forming apparatus as in Example 1, while supplying a one-component developer in the same manner as in Example 1, a durability evaluation test of the developer carrier was performed.

Example 17 200 parts of a resole type phenol resin solution (containing 50% methanol) 30 parts of graphite having a number average particle diameter of 1.5 μm 30 parts of conductive carbon black 130 parts of isopropyl alcohol 1 mm zirconia beads were added as media particles, dispersed in a sand mill for 2 hours, and zirconia beads were separated using a sieve to obtain a stock solution B-4.

To 380 parts of the stock solution of B-4, 15 parts of the conductive spherical particles A-2 used in Example 2 were added, and isopropyl alcohol was added so that the solid concentration became 32%. Disperse using glass beads for 1 hour,
Glass beads were separated using a sieve to obtain a coating liquid.
Using this coating solution, a conductive coating layer having a coating width of 310 mm was formed on an aluminum cylindrical tube having an outer diameter of 32 mmφ by a spray method, and then a 140 ° C.
The conductive coating layer was cured by heating for 0 minutes to produce a developer carrier C-17. The adhesion weight of the conductive coating layer after drying was 265 mg, and the layer thickness was 7 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier C-17.

The C-17 developer carrier was used in an image forming apparatus (corona charging means, corona transfer means) NP6060 (manufactured by Canon) shown in FIG. 4 having the developing apparatus shown in FIG. , A durability evaluation test of the developer carrying member was performed. The following was used as the one-component developer.・ 100 parts of polyester resin ・ 100 parts of magnetite ・ 2 parts of 3,5-di-tert-butylsalicylate chromium complex ・ 4 parts of low molecular weight polypropylene The above materials are kneaded, crushed and classified by a general dry toner production method, Fine powder (toner particles) having an average particle size of 6.6 μm was obtained. To 100 parts of the fine powder, 1.2 parts of hydrophobic colloidal silica was externally added to obtain a magnetic toner, and the magnetic toner was used as a one-component developer.

<Comparative Example 1> In place of the conductive spherical particles A-1, 380 parts of the stock solution of B-1 produced in Example 1 was replaced with amorphous graphite a- having a number average particle size of 17.0 μm.
A developer carrier D-1 was prepared in the same manner as in Example 1 except that 10 parts of 1 was added. The adhesion weight of the conductive coating layer after drying was 100 mg, and the layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier D-1. Using the developer carrying member of D-1 in the same image forming apparatus as in Example 1, a durability evaluation test of the developer carrying member was performed while supplying a one-component developer in the same manner as in Example 1.

<Comparative Example 2> Instead of the conductive spherical particles A-1, 380 parts of the stock solution of B-1 prepared in Example 1 was replaced with spherical particles having a number average particle size of 11.5 μm and having no conductivity. P
A developer carrying member D-2 was prepared in the same manner as in Example 1, except that 10 parts of the MMA particles a-2 were added. The adhesion weight of the conductive coating layer after drying was 100 mg, and the layer thickness was 8 μm.
m. Table 2 shows the physical properties of the conductive coating layer of the developer carrier D-2. Using the developer carrying member of D-2 in the same image forming apparatus as in Example 1, while supplying a one-component developer in the same manner as in Example 1, a durability evaluation test of the developer carrying member was performed.

Comparative Example 3 Coal bulk mesophase having a number average particle size of 4 μm or less as a conductive spherical particle using a Raikai machine (automatic mortar, manufactured by Ishikawa Plant) on 100 parts of a spherical phenol resin having a number average particle size of 37 μm. Pitch powder 16
Part is uniformly coated, subjected to thermal stabilization treatment in an oxidizing atmosphere, and then calcined at 2,200 ° C. to be graphitized to obtain spherical conductive carbon particles (conductive spherical particles a-3). Was. The physical properties of the conductive spherical particles a-3 are shown in Table 1. The number average particle size of the conductive spherical particles a-3 was 35 μm.
Met. A developer was prepared in the same manner as in Example 1 except that 5 parts of conductive spherical particles a-3 were added instead of the conductive spherical particles A-1 to 380 parts of the stock solution of B-1 produced in Example 1. Carrier D-3 was produced. The adhesion weight of the conductive coating layer after drying was 105 mg, and the layer thickness was 8 μm.
Table 2 shows the physical properties of the conductive coating layer of the developer carrier D-3. Using the developer carrying member of D-3 in the same image forming apparatus as in Example 1, a durability evaluation test of the developer carrying member was performed while supplying a one-component developer in the same manner as in Example 1.

<Comparative Example 4> As a conductive spherical particle, a hybridizer (manufactured by Nara Machinery Co., Ltd.) was used to obtain a number average particle diameter of 0.1.
Conductive treated spherical resin particles (conductive spherical particles a-4) obtained by coating 25 parts of conductive carbon black on 100 parts of 19 μm spherical PMMA particles were used. Table 1 shows the physical properties of the conductive spherical particles a-4. The number average particle size of the conductive spherical particles a-4 was 0.23 μm. In the same manner as in Example 1 except that 35 parts of conductive spherical particles a-4 were added to 380 parts of the stock solution of B-1 produced in Example 1 instead of the conductive spherical particles A-1, Body D-4
Was prepared. The adhesion weight of the conductive coating layer after drying is 105
mg, and the layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier D-4. Using the developer carrying member of D-4 in the same image forming apparatus as in Example 1, a durability evaluation test of the developer carrying member was performed while supplying a one-component developer in the same manner as in Example 1.

<Comparative Example 5> The following materials were kneaded, ground and classified as conductive spherical particles to obtain a number average particle size of 1
After obtaining conductive particles of 0.7 μm, conductive spherical resin particles (conductive spherical particles a-5) obtained by performing a sphering treatment using a hybridizer (manufactured by Nara Machinery).
Was used. Table 1 shows the physical properties of the conductive spherical particles a-5. The true density was 3.35 g / cm ³ .・ Styrene-dimethylaminoethyl methacrylate-divinylbenzene copolymer (copolymerization ratio: 90: 10: 0.05) 100 parts ・ Silver fine particles 300 parts Conductivity was added to 380 parts of the stock solution of B-1 produced in Example 1. Instead of the spherical particles A-1, 10 conductive spherical particles a-5 were used.
A developer carrying member D-5 was prepared in the same manner as in Example 1 except for adding a portion. The adhesion weight of the conductive coating layer after drying was 105 mg, and the layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier D-5. D-
Using the developer carrying member of No. 5 in the same image forming apparatus as in Example 1, while supplying the one-component developer in the same manner as in Example 1,
A durability test was performed on the developer carrier.

Comparative Example 6 The following materials were kneaded, pulverized and classified as conductive spherical particles to obtain a number average particle size of 1
5.6 μm conductive irregular shaped particles a-6 were obtained. Table 1 shows the physical properties of the conductive irregular-shaped particles a-6. 100 parts of styrene-dimethylaminoethyl methacrylate-divinylbenzene copolymer (copolymerization ratio: 90: 10: 0.05) 25 parts of conductive carbon black Next, a stock solution 380 of B-1 prepared in Example 1 In the part, the conductive amorphous particles a-6 instead of the conductive spherical particles A-1
Was added in the same manner as in Example 1 except that 10 parts of was added to prepare a developer carrying member D-6. The adhesion weight of the conductive coating layer after drying was 95 mg, and the layer thickness was 8 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier D-6.
Using the developer carrying member of D-6 in the same image forming apparatus as in Example 1, a durability evaluation test of the developer carrying member was performed while supplying a one-component developer in the same manner as in Example 1.

<Comparative Example 7> B-4 produced in Example 17
In place of the conductive spherical particles A-2,
Amorphous graphite having a number average particle size of 4.0 μm was
A developer carrying member D-7 was prepared in the same manner as in Example 17 except for adding a portion. The adhesion weight of the conductive coating layer after drying was 270 mg, and the layer thickness was 7 μm. Table 2 shows the physical properties of the conductive coating layer of the developer carrier D-7. D
Using the developer carrying member of -7 in the same image forming apparatus as in Example 17, a durability evaluation test of the developer carrying member was performed while supplying a one-component developer in the same manner as in Example 17.

[0088]

[Evaluation] A durability test was conducted for the following evaluation items.
Each developer carrier of the example and the comparative example was evaluated. Table 3 shows the evaluation results of durability of image density, durability fog and durability ghost under low temperature and low humidity. Also, in Table 4,
The evaluation results of image density durability, durability fog and durability ghost under high temperature and high humidity are shown. Further, Table 5 shows the results of evaluation of the wear resistance and the stain resistance.

The number of endurance sheets was as in Examples 1 to 16 and Comparative Example 1.
As for the samples Nos. To 6, the measurement was performed up to 40,000 sheets, and the measurement was performed during the endurance of 10 sheets and 20,000 sheets. In addition, in the case of Example 17 and Comparative Example 7, the measurement was performed up to 400,000 sheets, and the measurement was performed at the time of endurance of 10 sheets and 200,000 sheets. The durable environment includes low temperature / low humidity (L / L) and high temperature / high humidity (H /
H) The test was performed for the following two durable environments. In particular,
Under low temperature / low humidity (L / L), 15 ° C./10% RH environment, and under high temperature / high humidity (H / H), 32.5 ° C./85
% RH.

(1) Image Density (Durable Density) Using a reflection densitometer RD918 (manufactured by Macbeth), the density of a solid black portion at the time of solid printing was measured at five points, and the average value was defined as the image density.

(2) Fog density (durable fog) The reflectance (D ₁ ) of the solid white portion of the recording paper on which the image was formed was measured, and the unused recording paper having the same cut as the recording paper used for the image formation was measured. The reflectivity (D ₂ ) was measured, and the value of D ₁ -D ₂ was calculated as 5
Points were obtained, and the average value was defined as the fog density. Reflectance is TC
-6DS (manufactured by Tokyo Denshoku).

(3) Ghost (Durable Ghost) The position of the developing sleeve where the solid white portion and the solid black portion have developed the adjacent image comes to the developing position at the next rotation of the developing sleeve, and develops the halftone image. Then, the difference in shading appearing on the halftone image was visually evaluated based on the following criteria. ：: No difference in shade was observed. △: A slight difference in shading is observed. Δ: Some difference in shading is observed, but practical. X: The difference in shading is remarkable, and it is not practical.

(4) Abrasion resistance of the conductive coating layer The center line average roughness (Ra) of the surface of the developer carrier before and after endurance.
Was measured.

(5) Stain Resistance of the Conductive Coating Layer The surface of the developer carrier after durability was observed by SEM, and the degree of toner contamination was evaluated based on the following criteria. ：: Only slight contamination is observed. ○ △: Slight contamination is observed. Δ: Contamination is partially observed. X: Remarkable contamination is observed.

Table 1 Physical properties of added particles constituting the conductive coating layer

Table 2 Physical Properties of Conductive Coating Layer of Developer Carrier

Table 3 Evaluation results (durable density, durable fog, durable ghost under low temperature and low humidity)

Table 4 Evaluation results (durable density, durable fog, durable ghost under high temperature and high humidity)

Table 5 Evaluation results (wear resistance, stain resistance)

[0100]

As described above, according to the present invention, the durability is improved as compared with the conventionally used developer carrier,
It is possible to maintain a state where a good image can be provided for a long time. Therefore, according to the present invention, a highly durable developer carrier that does not cause deterioration such as abrasion of the conductive coating layer on the surface of the developer carrier due to repeated copying or durability and toner contamination does not cause a decrease in image density and generation of ghost. ,
It is possible to provide a high-quality image without deterioration of fog for a long time.

[Brief description of the drawings]

FIG. 1 is a schematic view of a developing device according to an embodiment having a developer carrier on which a conductive resin coating layer of the present invention is formed.

FIG. 2 is a schematic view of a developing device of another embodiment of the present invention in which a regulating member of a developer layer is different in the developing device of FIG.

FIG. 3 is a schematic view of a developing device according to still another embodiment of the present invention, in which a developer layer regulating member in the developing device of FIG. 1 is different.

FIG. 4 is a schematic explanatory view of the image forming apparatus of the present invention.

FIG. 5 is a schematic explanatory view of a specific example of the process cartridge of the present invention.

FIG. 6 is a schematic view of a conventional developing device having a developer carrier on which a resin coating layer is not formed.

[Explanation of symbols]

 1: photosensitive drum (electrostatic latent image holding body) 2: magnetic regulation blade 3: hopper (developer container) 4: developer (toner) 5: magnet roller 6: metal cylindrical tube 7: conductive resin coating layer 8: Developing sleeve 9: Developing bias power supply 10: Stirring blade 11: Elasticity regulating blade 12: Gap 101: Photosensitive drum 103: Developer container 104: One-component developer 105: Multi-pole permanent magnet 108: Developing sleeve 109: Bias applied voltage 111: Elasticity regulating blade 113: Contact (roller) transfer means 114: Voltage applying means 115: Exposure 116: Erase exposure 118: Heating / pressing roller fixing device 118: Cleaning means 118a: Cleaning blade 119: Contact (roller) charging means 120 : Developing means N1, N2, S1, S2: magnetic pole A: developing sleeve rotating method B: a photosensitive drum rotation direction D: the developing region P: recording medium

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Michiko Orihara 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Mayuko Maruyama 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Takuya Toyooka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazuki Saiki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-3-200986 (JP, A) JP-A-1-268759 (JP, A) JP-A-3-163575 (JP, A) JP-A-4-301636 (JP, A) Kaihei 2-287373 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G03G 15/08 501 G03G 15/09-15/09 101

Claims (43)

(57) [Claims] 1. A developer carrier having at least a substrate and a conductive coating layer covering the substrate, wherein the conductive coating layer includes a binder resin and a number average particle dispersed in the binder resin. A developer carrier comprising at least conductive spherical particles having a diameter of 0.3 to 30 μm and a true density of 3 g / cm ³ or less. 2. The ratio of the major axis / minor axis of the conductive spherical particles is as follows:
The developer carrier according to claim 1, wherein the developer carrier is in a range of 1.0 to 1.5. 3. The conductive spherical particles have a volume resistivity of 10 ⁶ Ω.
· Developer carrying member according to claim 1 or 2, characterized in that cm or less. 4. The conductive spherical particles, 2.7 g / cm ³ or less
2. The method according to claim 1, wherein the true density is as follows.
Developer carrier. 5. The conductive spherical particles have a content of 0.9 to 2.5 g / g.
2. The development according to claim 1, which has a true density of cm ^3.
Agent carrier. 6. The conductive spherical particles according to any one of claims 1 to 5, characterized in that carbon particles developer carrying member. 7. The developer carrier according to claim 6 , wherein the surface of the carbon particles is plated with a conductive metal, a conductive metal oxide, or both. 8. The conductive spherical particles, wherein the surface of the resin particles is subjected to a conductive treatment.
The developer carrier according to any one of the above. 9. The conductive spherical particles, a developer carrying member according to claim 1 in which the conductive fine particles in the resin particles, characterized in that which is contained dispersed. 10. The conductive spherical particles have a spherical resin particle surface.
Particles coated with bulk mesophase pitch
This allows the bulk mesophase pitch to cover the surface
Carbonized and / or graphitized the obtained spherical resin particles.
The particles according to any one of claims 1 to 5, wherein
2. The developer carrier according to claim 1. 11. The conductive coating layer, in addition to the conductive spherical particles, a developer carrying member according to any one of claims 1 to 10, characterized in that further contains a lubricating particles . 12. The lubricating particles are graphite, molybdenum disulfide, boron nitride, mica, graphite fluoride,
Silver-niobium selenide, calcium chloride-graphite,
12. The developer carrier according to claim 11 , comprising at least one selected from the group consisting of talc and a fatty acid metal salt. 13. The conductive coating layer, in addition to the conductive spherical particles, a developer carrying member according to any one of claims 1 to 12, characterized by containing conductive particles further . 14. The conductive fine particles are carbon black,
A metal oxide, a metal, and at least one selected from the group consisting of inorganic fillers, wherein
14. The developer carrier according to any one of the above items 13 . 15. The conductive coating layer center line average roughness of the surface of (Ra) is developed according to any one of claims 1 to 14, characterized in that a 0.2~4.5μm Agent carrier. 16. A developer container accommodating a developer, and a thin layer of the developer accommodated in the developer container is formed on the surface and carried, and the developer is conveyed to a development area. in the developing device having a developer carrying member for developing and wherein the developer carrying member is a developer carrying member according to any one of claims 1 to 15. 17. The developing device according to claim 16 , further comprising a developer layer thickness regulating member for forming a thin layer of the developer on the developer carrier. 18. The developing device according to claim 17 , wherein the developer layer thickness regulating member is a magnetic regulating blade. 19. The developing device according to claim 17 , wherein the developer layer thickness regulating member is elastically pressed against the developer carrying member via the developer. 20. The developing device according to claim 19 , wherein the developer layer thickness regulating member is an elastic regulating member. 21. A one-component developer carried on a developer carrier.
The thickness of the developer layer of the image agent is determined by the surface of the electrostatic latent image holding member and the developer
The developer carrying agent should be thinner than the minimum gap with the body surface.
A developer layer of the one-component developer is formed on a carrier.
The method according to any one of claims 16 to 20, wherein
Developing device. 22. The developing device forms an oscillating electric field in a developing area.
Characterized by having a power supply having means for achieving
The developing device according to any one of claims 16 to 21, wherein
Place. 23. A developing device, comprising :
Features a power supply for applying assault voltage
The developing device according to any one of claims 16 to 21, wherein
Place. 24. The developer according to claim 16, wherein the developer is a magnetic one-component developer containing a magnetic toner .
The developing device according to claim 1 . 25. developer, claim 16, 1, which is a non-magnetic one-component developer comprising non-magnetic toner
The developing device according to 7 , 19 or 20 . 26. developer, claims 16-2, which is a two-component developer containing toner and carrier
The developing device according to any one of 0 to 0 . 27. An electrostatic latent image holder for holding an electrostatic latent image, and (ii) a developing device for converting the electrostatic latent image into a developed image in a developing area with a developer. in the image forming apparatus having an image forming apparatus, wherein the developing device is a developing device according to any one of claims 16-26. 28. The image forming apparatus according to claim 27 , wherein the electrostatic latent image holding member is a photoconductor for electrophotography. 29. The image forming apparatus according to claim 2 , further comprising a transfer unit for transferring the developed image onto a recording material.
29. The image forming apparatus according to 7 or 28 . 30. The image forming apparatus according to any one of claims 27 to 29, characterized in that it has further fixing means for fixing the developed image transferred onto the recording material. 31. An image forming apparatus comprising: (i) an electrostatic latent image holding member for holding an electrostatic latent image; and (ii) developing means for converting the electrostatic latent image into a developed image with a developer in a developing area. In a process cartridge detachably mountable to an image forming apparatus main body integrally provided, a developing means forms a developer container containing a developer and a thin layer of the developer contained in the developer container on a surface. and carrying, and a has a developer carrying member for carrying the developer to the developing area, the developer carrying member is the developer carrying member according to any one of claims 1 to 15 A process cartridge characterized by the above-mentioned. 32. The process cartridge according to claim 31 , wherein the developing means further includes a developer layer thickness regulating member for forming a thin layer of the developer. 33. The process cartridge according to claim 32 , wherein the developer layer thickness regulating member is a magnetic regulation blade. 34. The process cartridge according to claim 32 , wherein the developer layer thickness regulating member is elastically pressed against the developer carrying member via the developer. 35. The process cartridge according to claim 32 , wherein the developer layer thickness regulating member is an elastic regulating member. 36. A one-component developer carried on a developer carrier.
The thickness of the developer layer of the image agent is determined by the distance between the surface of the electrostatic latent image holding member and the amount of the developer carried.
The developer carrying agent should be thinner than the minimum gap with the body surface.
A developer layer of the one-component developer is formed on a carrier.
The method according to any one of claims 31 to 35, wherein
Process cartridge. 37. The developing device forms an oscillating electric field in a developing area.
Characterized by having a power supply having means for achieving
The process according to any one of claims 31 to 36.
Cartridge. 38. A developing device, comprising :
Features a power supply for applying assault voltage
A process according to any one of claims 31 to 36.
cartridge. 39. The developer according to claim 31, wherein the developer is a magnetic one-component developer containing a magnetic toner .
The process cartridge according to claim 1 . 40. A developer according to claim 31, characterized in that a non-magnetic one-component developer comprising non-magnetic toner, 3
The process cartridge according to 2 , 34, or 35 . 41. A developer, 31. to 3, characterized in that a two-component developer containing toner and carrier
6. The process cartridge according to any one of 5 . 42. The electrostatic latent image holding member is, the process cartridge according to any one <br/> of claims 31 to 41, characterized in that an electrophotographic photosensitive member. 43. A cartridge wherein at least one of a cleaning means and a primary charging means is integrally formed as a cartridge in addition to an electrophotographic photosensitive member as an electrostatic latent image holding member and a developing means. Any of 31 to 42
2. The process cartridge according to claim 1 .