JP2003043830A - Process cartridge, electrophotographic device, image forming device and intermediate transfer belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process cartridge for realizing the facilitation of maintenance and the miniaturization and the reduction of cost of a device and yielding an excellent image even after the process cartridge is transported or left unused for a long period of time. SOLUTION: This process cartridge integrally supports an electrophotographic photoreceptor, an intermediate transfer belt, a primary transfer means for primarily transferring a toner image from the photoreceptor to the intermediate transfer belt, and a charge imparting means for imparting charge whose polarity is opposite to the polarity at the primary transfer to the toner on the intermediate transfer belt in order to restore the toner on the intermediate transfer belt to the photoreceptor and clean the intermediate transfer belt. The intermediate transfer belt is fabricated so that its elastic modulus obtained when it is extended in a peripheral direction by 0.5 to 0.6% is 500 to 4000 MPa, its rupture elongation in the circumferential direction is 5 to 850%, and its surface roughness Ra is <=1 μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge, an electrophotographic apparatus, an image forming method, and an intermediate transfer belt for the process cartridge.

[0002]

2. Description of the Related Art An electrophotographic apparatus using an intermediate transfer belt is an image formed product in which a plurality of component color images of full-color image information and multi-color image information are sequentially laminated and transferred to synthesize and reproduce a full-color image or a multi-color image. It is effective as an electrophotographic apparatus for full-color or multi-color image formation that outputs a.

A full-color electrophotographic apparatus having an intermediate transfer belt is a conventional electrophotographic apparatus in which a second image carrier is attached to or adsorbed on a transfer drum, and an image is transferred from the electrophotographic photosensitive member to the second image carrier. Compared with a full-color electrophotographic apparatus having a transfer device, such as the transfer device disclosed in Japanese Patent Laid-Open No. 63-301960, the transfer material is processed and controlled (for example, gripped by a gripper, attracted, given a curvature, etc.). ) Is required to transfer an image from an intermediate transfer belt, and therefore, the width from thin paper (40 g / m ² paper) such as envelopes, postcards and label paper to thick paper (200 g / m ² paper) There is an advantage that the second image carrier can be selected in a wide variety, regardless of whether the second image carrier is narrow or narrow.

In addition, the belt shape increases the degree of freedom in arranging the belt inside the electrophotographic apparatus as compared with the case where a rigid cylinder shape such as an intermediate transfer drum is used, and space is saved. There is also an advantage that the device body can be downsized and the cost can be reduced by effective use.

However, at present, the life of the intermediate transfer belt is shorter than that of the main body of the electrophotographic apparatus, so that replacement is essential. At the same time, it is necessary to install and treat a waste toner container that collects the toner remaining on the intermediate transfer belt.

In addition to these, in an electrophotographic apparatus such as a printer or a copying machine, many parts such as an electrophotographic photosensitive member, a developing device, and a toner need to be replaced.

As a method for making these replacement parts into units (process cartridges) and easily attaching and detaching them from the main body, Japanese Patent Laid-Open No. 8-137181 discloses an intermediate transfer belt and an electrophotographic photosensitive member as separate units from the main body. There is disclosed a technique of arranging so as to be easily detachable.

However, with this means, the number of units to be replaced is large and the user's operation becomes complicated. Further, since each unit is designed and arranged independently of each other, problems such as an increase in size of the main body and an increase in cost occur.

As a method for solving this problem, it is preferable to replace the intermediate transfer belt and the electrophotographic photosensitive member, which are replacement parts, into an integral unit (process cartridge), which is simultaneously detached from the main body and replaced. Technology is
JP-A-6-110261, JP-A-10-1773
No. 29 and Japanese Patent Application Laid-Open No. 11-30944.

However, the method in which the intermediate transfer belt and the electrophotographic photosensitive member are constructed as an integral unit and can be easily attached to and detached from the main body, that is, a process cartridge in which the intermediate transfer member and the electrophotographic photosensitive member are integrated is Unlike the case where the intermediate transfer belt is set when the main body is installed, some problems caused by the intermediate transfer belt occur.

One of them is a reduction in belt strength due to the tension applied to the intermediate transfer belt.

Normally, the intermediate transfer belt needs to be tensioned so as to be surely driven and rotated without slipping, and the intermediate transfer belt integrated cartridge remains stationary while being tensioned for a long time before being actually used. It will be in the state of doing. As a result, creep occurs in the intermediate transfer belt and the circumferential length increases.

The increased circumference is absorbed by the tension roller having a stroke to some extent, but the elastic modulus is lower than the initial set value due to the elongation, and the color shift occurs during actual use. There is a problem that the image quality deteriorates and the image quality deteriorates.

Further, in the intermediate transfer belt having a small elongation, a big problem is that cracks are generated due to tension and vibration during distribution.

It has been known that the creep phenomenon is promoted in a higher temperature environment, and the process cartridge for integrally supporting the intermediate transfer belt and the electrophotographic photosensitive member is designed in consideration of the high temperature environment received during the distribution stage. Is required.

In particular, in recent years, the technology of electrophotographic devices has advanced, and in printers and copiers of the digital developing system, it is possible to develop fine and dense pixels of 600 dpi or more by reducing the exposure spot diameter and increasing the density. In addition to that, high-quality images are being obtained by precise control of the electric field.

As a result, the change in elastic modulus and the roughness of the surface of the intermediate transfer belt, which have not been a problem in the past, may affect the image quality, which is an important issue.

However, in the above-mentioned conventional technique, the process cartridge integrally supporting the intermediate transfer belt and the electrophotographic photosensitive member does not take any measures against a long time leaving during transportation or storage, and the process cartridge is distributed. It cannot be said that it was designed in consideration of the process. Therefore, in the conventional process cartridge that integrally supports the intermediate transfer belt and the electrophotographic photosensitive member, problems such as an increase in management cost and an increase in user complaints due to strict storage and limitation of a use period occur.

In addition to these, the reduction of running cost is an important issue, and the process cartridge for integrally supporting the intermediate transfer belt and the electrophotographic photosensitive member, which are replacement parts, requires further cost reduction. However, in order to facilitate handling, it is necessary to give sufficient consideration to downsizing and disposal of waste toner.

As described above, a process cartridge which completely solves the technical problem peculiar to a process cartridge for integrally supporting the intermediate transfer belt and the electrophotographic photosensitive member, and an electrophotographic apparatus having the process cartridge are obtained. There isn't.

[0021]

SUMMARY OF THE INVENTION An object of the present invention is to facilitate maintenance, downsize the device, and reduce the cost.
A process cartridge capable of obtaining a good image even after long-term transportation or leaving, an electrophotographic apparatus having the process cartridge, an image forming method using the electrophotographic apparatus,
Another object is to provide an intermediate transfer belt for the process cartridge.

[0022]

The inventors of the present invention have made earnest studies on simplification of maintenance, downsizing of electrophotographic apparatus main body and process cartridge, cost reduction, and improvement of image quality. As a result, the intermediate transfer belt is obtained. It has been found that the initial goal can be achieved by using a process cartridge that integrally supports the electrophotographic photosensitive member and the electrophotographic photosensitive member, and further adopting some measures.

That is, the present invention is a process cartridge which is detachably mountable to the main body of an electrophotographic apparatus and has an electrophotographic photosensitive member for carrying a toner image and an abutting portion for contacting the electrophotographic photosensitive member. An intermediate transfer belt, a primary transfer means for primarily transferring an image of the toner from the electrophotographic photosensitive member to the intermediate transfer belt at the contact portion, and toner on the intermediate transfer belt at the contact portion. In order to return the toner to the electrophotographic photosensitive member and clean the intermediate transfer belt, a charge applying unit for applying a charge having a polarity opposite to the polarity of the toner at the time of the primary transfer to the toner on the intermediate transfer belt is integrated. The intermediate transfer belt is supported by 0.5% in the circumferential direction.
Elastic modulus when stretched from 0.5 to 0.6%
~ 4000 MPa, the breaking elongation in the circumferential direction is 5% ~ 8
The process cartridge has a surface roughness Ra of 50% and a surface roughness Ra of 1 μm or less.

In the present invention, the electrophotographic photoreceptor for carrying the toner image, the charging means for charging the electrophotographic photoreceptor, and the electrophotographic photoreceptor charged by the charging means are statically charged. An exposure unit for forming an electro-latent image, and a developing unit for developing the electrostatic latent image of the electrophotographic photosensitive member formed by the exposure unit with toner to form a toner image on the electrophotographic photosensitive member. An intermediate transfer belt having a contact portion with the electrophotographic photosensitive member for secondarily transferring the toner image transferred after the primary transfer of the toner image from the electrophotographic photosensitive member, A primary transfer means for primarily transferring an image of the toner from the electrophotographic photosensitive member to the intermediate transfer belt at the corresponding contact portion, and toner on the intermediate transfer belt at the corresponding contact portion Return to the intermediate transfer belt A charge applying unit for applying a charge having a polarity opposite to that of the toner at the time of the primary transfer to the toner on the intermediate transfer belt for cleaning, and an electrophotographic photosensitive member for cleaning the electrophotographic photosensitive member. A process cartridge having a body cleaning means, integrally supporting at least the electrophotographic photosensitive member, the intermediate transfer belt, the primary transfer means, and the charge applying means, and being detachable from the main body of the electrophotographic apparatus. The intermediate transfer belt has a modulus of elasticity of 500 MPa to 4000 MPa when stretched from 0.5% to 0.6% in the circumferential direction, and a breaking elongation of 5% to 850% in the circumferential direction. , Surface roughness Ra is 1
The electrophotographic apparatus is characterized by having a thickness of μm or less.

Further, the present invention is formed by a charging step of charging the electrophotographic photosensitive member, an exposure step of forming an electrostatic latent image on the electrophotographic photosensitive member charged in the charging step, and the exposure step. The electrostatic latent image on the electrophotographic photoreceptor is developed with toner,
A developing step for forming a toner image on the electrophotographic photoreceptor,
A primary transfer step in which the image of the toner formed in the developing step is primarily transferred by a primary transfer means from the electrophotographic photosensitive member to an intermediate transfer belt having a contact portion with the electrophotographic photosensitive member; A secondary transfer step of secondarily transferring the image of the toner primarily transferred in the transfer step onto a transfer material, and a polarity opposite to the polarity of the toner at the primary transfer step in the toner on the intermediate transfer belt by the charge applying means. An electric charge applying step of applying a polar electric charge; an intermediate transfer belt cleaning step of returning the toner on the intermediate transfer belt to the electrophotographic photosensitive member at a corresponding contact portion to clean the intermediate transfer belt; An image forming method comprising: an electrophotographic photosensitive member cleaning step of cleaning a body, wherein at least the electrophotographic photosensitive member, the intermediate transfer belt, the primary transfer means, and the charge. An image forming method using an electrophotographic apparatus having a process cartridge that integrally supports a supplying unit and is detachably attached to an electrophotographic apparatus main body, wherein the intermediate transfer belt is 0.5% to 0% in a circumferential direction. In the image forming method, the elastic modulus when stretched to 0.6% is 500 MPa to 4000 MPa, the breaking elongation in the circumferential direction is 5% to 850%, and the surface roughness Ra is 1 μm or less. is there.

The present invention is also an intermediate transfer belt for the above process cartridge.

[0027]

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

The process cartridge of the present invention is a process cartridge that integrally supports the intermediate transfer belt and the electrophotographic photosensitive member (hereinafter, also referred to as an intermediate transfer belt-electrophotographic photosensitive member integrated cartridge).

In the present invention, in order to downsize the process cartridge and reduce the cost, the cleaning mechanism for the intermediate transfer belt charges the transfer residual toner to the opposite polarity,
At the time of primary transfer, it is returned to the electrophotographic photoreceptor at the same time, so-called,
A primary transfer simultaneous cleaning method (also called a bias cleaning method) is adopted.

Specifically, a voltage is applied to a charge-giving member arranged on the intermediate transfer belt so as to be separable and contactable, so that the toner remaining on the intermediate transfer belt at the time of secondary transfer is charged with a charge having a polarity opposite to that at the time of primary transfer. Is applied to the electrophotographic photosensitive member by a primary transfer electric field at the subsequent temporary transfer portion.

The toner returned from the intermediate transfer belt to the electrophotographic photosensitive member is removed by a cleaning means such as a cleaning blade for cleaning the electrophotographic photosensitive member.

According to this method, cleaning blades are arranged on both the electrophotographic photosensitive member and the intermediate transfer belt, and a waste toner feeding mechanism and a container are installed.
It has a great effect on downsizing and cost reduction of the cartridge.

Further, in the present invention, since the intermediate transfer belt is subjected to the tension for a long time and the strength is designed in consideration of the occurrence of the creep phenomenon due to the fluctuation of the environment, a long time elapses after the production. Even with the above-mentioned intermediate transfer belt cartridge, it is possible to obtain a good image without causing a problem.

Specifically, the elastic modulus when the intermediate transfer belt is stretched from 0.5% to 0.6% in the circumferential direction is 500.
By setting the pressure to MPa or more, it is possible to reduce the color misregistration during image formation.

On the other hand, when the elastic modulus exceeds 4000 MPa, the rigidity is too high and smooth rotation of the intermediate transfer belt is hindered.

The intermediate transfer belt is 0.5% in the circumferential direction.
If the elongation at break when stretched from 0.5 to 0.6% is less than 5%, the belt becomes brittle and breaks with a slight elongation. Therefore, while being tensioned until used,
In the case of a process cartridge that can be stored for a long period of time, there is a problem that the life of the intermediate transfer belt is shortened.

On the other hand, when the elongation at break exceeds 850%, the elongation is too large to cause expansion and contraction when the intermediate transfer belt rotates, resulting in deterioration of color misregistration.

It is necessary to consider the surface smoothness of the intermediate transfer belt. If the surface roughness Ra exceeds 1 μm, the transfer performance will be affected and the reproducibility of the halftone image, such as roughness and fine lines, will deteriorate. To do. In addition, the electric charge applied to the secondary transfer residual toner is uneven, the electric charge does not sufficiently return to the electrophotographic photosensitive member, and cleaning failure of the intermediate transfer belt in which the previous image remains in the image printed next during continuous printing occurs.

In particular, the problem with these images is 600
It remarkably appears in an electrophotographic apparatus having a digital exposure means for forming an electrostatic latent image on the surface of an electrophotographic photosensitive member by a digital system of dpi or more.

On the other hand, in order to reduce the size and cost of the intermediate transfer belt-electrophotographic photosensitive member integrated cartridge,
The shape of the electrophotographic photosensitive member incorporated in the cartridge is also important. Therefore, the electrophotographic photosensitive member is preferably a drum-shaped electrophotographic photosensitive member (photosensitive drum) having a small diameter and made of a rigid body having a diameter of 60 mm or less, which has a simple driving mechanism and is easily miniaturized.

For the same purpose as described above, it is more preferable that the intermediate transfer belt is stretched by two rollers because the number of parts and the size can be reduced.

The tension roller for applying a tension to the intermediate transfer belt is designed to cope with the elongation of the intermediate transfer belt.
It is necessary to slide at least 1 mm or more in the extension direction of the intermediate transfer belt, and in order to reliably drive the intermediate transfer belt without slipping, it is necessary to stretch the intermediate transfer belt with a force of 5N or more. preferable.

The resistance value of the intermediate transfer belt needs to be adjusted. The range of the volume resistivity of the intermediate transfer belt capable of obtaining a good image is 1 × 10 ⁶ Ω · cm to 8 × 10 ¹³ Ω.
・ It is cm. If the volume resistivity is less than 1 × 10 ⁶ Ω · cm, a sufficient transfer electric field may not be obtained, which may result in image dropouts and shading. On the other hand, the volume resistivity of 8 × ^{10 1 3}
If it is higher than Ω · cm, the transfer voltage also needs to be high,
This causes an increase in the size of the power supply and an increase in cost.

The thickness of the intermediate transfer belt is from 40 μm to
The range of 300 μm is preferable. If the thickness is less than 40 μm, the molding stability may be poor, the thickness may be uneven, the durability may be insufficient, and the belt may be broken or cracked. on the other hand,
If it exceeds 300 μm, the material increases and the cost increases, and the difference in peripheral speed between the inner surface and the outer surface at the stretch shaft part of the printer and the like becomes large, and problems such as image scattering due to contraction of the outer surface easily occur, and bending In some cases, the durability may be reduced and the rigidity of the belt may be too high to increase the driving torque, resulting in an increase in size of the main body and an increase in cost.

In the present invention, the process cartridge for integrally supporting the intermediate transfer belt and the electrophotographic photosensitive member is used, but the process cartridge may be integrated at the time of use by the user, and may be handled in the manufacturing process or after recovery. Considering the ease of disassembly, for example, the process cartridge
It is preferable to design so that it can be separated into several smaller units such as an intermediate transfer belt unit and an electrophotographic photoreceptor unit.

The means for obtaining the elastic modulus of the present invention is not particularly limited, and the elongation at break and 0.5% can be selected depending on the selection of the resin as the raw material of the intermediate transfer belt and various additives.
It may be adjusted so that the elastic modulus when stretched from 0.1 to 0.6% falls within the numerical range of the present invention.

For example, by mixing a filler such as inorganic particles, a reinforcing effect is obtained and the elastic modulus is improved.
At this time, the elastic modulus can be adjusted within the range of the present invention by selecting the material and amount of the filler and the type of resin.

Further, if the shape of the filler is fibrous or plate-like, a high reinforcing effect can be obtained even when elongation occurs.

Furthermore, a method of producing an intermediate transfer belt by blending two or more kinds of incompatible resins having different elongations is also effective. When an intermediate transfer belt is manufactured using such a material, each resin is finely separated and exists in a layer or fiber inside the belt. In the initial stage, the intermediate transfer belt made in this way obtains strength with a hard resin with a small elongation at break, but creep occurs over time, and when the resin with a small elongation at break exceeds the yield point, Instead, since the resin having a large elongation maintains the strength, it is possible to prevent the elastic modulus from rapidly decreasing.

The means for adjusting the surface roughness is not particularly limited either.

For example, by selecting the melting characteristics of the resin material used in extrusion molding and adjusting the temperature conditions and cooling conditions during molding, the molded product melt-extruded into a film is solidified from the molten state. There is a method of adjusting so that a smoother surface can be obtained.

Further, there is a method in which, after molding into a belt shape, a smooth mold is applied and heated to process it so that it has a surface condition equivalent to that of the mold, and a belt surface is polished.

As the method of manufacturing the intermediate transfer belt, a manufacturing method which can manufacture a seamless belt, has high manufacturing efficiency, and can reduce costs is preferable.

As a method therefor, there may be mentioned a method of producing a belt by continuously extruding it from an annular die and then cutting it to a required length. Specifically, a melt extrusion step of melt extruding from an annular die to obtain a tubular film, and a gas is injected into the inside of the tubular film melt extruded in the melt extrusion step to adjust the internal volume, A diameter control step for controlling the diameter of the film, and a member for supporting the film are not used until the tubular film melt-extruded by the melt-extrusion step and the diameter is controlled by the diameter control step is cooled and solidified. A method for manufacturing an intermediate transfer belt, comprising: a tubular film forming step of forming a tubular film having a diameter larger than the annular die, and a cutting step of cutting the tubular film formed by the tubular film forming step (inflation Called molding) is preferred.

It is more preferable that the thickness of the tubular film formed by the tubular film forming step is 1/3 or less of the width of the gap of the annular die.
It is even more preferably 5 or less. This represents the stretched state of the material. If the thickness of the tubular film is larger than 1/3 of the width of the gap of the annular die, the stretching of the material will be insufficient and the strength will decrease. Problems such as uneven resistance and thickness may occur.

Further, the diameter of the tubular film formed by the tubular film forming step (outer diameter of the tubular film) is 50% of the diameter of the gap of the annular die (outer diameter of the gap of the annular die). ˜400% is more preferred, and 101% to 300% is even more preferred. When the outer diameter exceeds 400%, it is largely stretched in the circumferential direction, and when it is less than 50%, it is almost stretched only in the flow direction (extrusion direction), which lowers the molding stability. However, it may be difficult to secure the thickness and strength required to obtain the effects of the present invention.

An example of a method of manufacturing the intermediate transfer belt for the process cartridge of the present invention will be described below. However, the present invention is not limited thereto.

FIG. 3 shows an example of an apparatus for manufacturing the intermediate transfer belt used in the process cartridge of the present invention. This manufacturing apparatus mainly has an extruder, an extrusion die, and a gas blowing device.

First, a molding resin, a conductive agent, an additive and the like are pre-mixed in accordance with a desired formulation, and the kneading-dispersed molding raw material is put into a hopper 102 provided in the extruder 100.

In the extruder 100, the set temperature and the screw configuration of the extruder are selected so that the raw material for molding has a melt viscosity that enables belt molding in the subsequent step, and the raw materials are uniformly dispersed. . The forming raw material is melted and kneaded in the extruder 100 to form a molten material, which enters the annular die 103.

The annular die 103 is provided with a gas introduction passage 104, and gas is blown into the center of the annular die 103 from the gas introduction passage 104, whereby the die 10 is formed.
The melt that has passed 3 expands and expands in the radial direction to form the tubular film 110.

The gas blown at this time is other than air,
Nitrogen, carbon dioxide, argon, etc. can be selected.

The expanded molded body has an external cooling ring 105.
It is pulled up while being cooled by. Usually, in an inflation device, a tube is crushed from the left and right by a stabilizer 106, folded into a sheet, and pinched by a pinch roller 107 so as to prevent the internal air from escaping, and then taken at a constant speed.

Then, the taken film is cut by the cutting device 108 to obtain a tubular film having a desired size.

Next, the tubular film is processed using a mold for the purpose of adjusting the surface smoothness and dimensions and removing the creases formed on the film during molding.

Specifically, there is a method of using a set of cylindrical molds made of materials having different thermal expansion coefficients and having different diameters.

The coefficient of thermal expansion of the small-diameter cylindrical shape (inner mold) is made larger than that of the large-diameter cylindrical shape (outer mold),
After covering the tubular film molded in the inner mold, the inner mold is inserted into the outer mold so that the tubular film is sandwiched between the inner mold and the outer mold. The gap between the molds is calculated by the difference between the heating temperature and the coefficient of thermal expansion of the inner and outer molds and the required pressure.

The mold set in the order of the inner mold, the tubular film and the outer mold is heated to near the softening point temperature of the resin. Upon heating, the inner mold having a large coefficient of thermal expansion expands more than the outer mold, and uniform pressure is applied to the entire surface of the tubular film. At this time, the surface circle of the resin film which has reached the vicinity of the softening point is pressed against the inner surface of the outer mold which has been processed to be smooth, and the smoothness of the surface of the resin film is improved. Then, by cooling and removing the film from the mold, a smooth surface property can be obtained.

Thereafter, the reinforcing member, the guide member, and the position detecting member are attached and precision cut as required to manufacture the intermediate transfer belt.

Further, although the explanation was for the single-layer belt, in the case of two layers, an extruder 101 is additionally arranged as shown in FIG. Extruder 11 to annular die 103
0 kneading melt is sent and two layers are simultaneously expanded and expanded.
A layer belt can be obtained.

Of course, when the number of layers is three or more, an extruder may be prepared according to the number of layers.

As described above, in the method of manufacturing the intermediate transfer belt, not only a single layer but also a multilayered intermediate transfer belt can be molded in a single step and in a short time with high dimensional accuracy. The fact that this short-time molding is possible means that mass production and low-cost production are possible.

Of the molding raw materials used for the intermediate transfer belt for the process cartridge of the present invention, the resin which is the main material is not particularly limited as long as it satisfies the characteristics of the intermediate transfer belt of the present invention. Olefin resin such as polyethylene and polypropylene, polystyrene resin, acrylic resin, polyester resin, polycarbonate, sulfur containing resin such as polysulfone, polyethersulfone and polyphenylene sulfide, polyvinylidene fluoride and polyethylene-tetrafluoroethylene copolymer Fluorine-containing resin, polyurethane resin, silicone resin, ketone resin, polyvinylidene chloride, thermoplastic polyimide resin, polyamide resin, modified polyphenylene oxide resin, etc., and one or two of these various modified resins or copolymers. It is possible to use more than kind. However, the material is not limited to the above materials.

Next, the additive mixed for adjusting the electric resistance value of the intermediate transfer belt for the process cartridge of the present invention is not particularly limited, but as the conductive filler for adjusting the resistance, There are carbon black and various conductive metal oxides.As non-filler resistance modifiers, low molecular weight ionic conductive materials such as various metal salts and glycols, and electrification containing ether bonds and hydroxyl groups in the molecule. Examples thereof include an anti-resin resin or an organic polymer compound having electronic conductivity.

What is needed here is the dispersed state of each additive and the components of the resin such as the intermediate transfer belt, and the effect of the present invention is obtained if the particles are aggregated or some of the components are extremely separated. Hard to get. The choice of materials and means of dispersion is important.

Next, FIG. 1 shows an example of an electrophotographic apparatus using the intermediate transfer belt-electrophotographic photosensitive member integrated cartridge of the present invention.

FIG. 1 shows a color electrophotographic apparatus such as a color copying machine or a color laser beam printer.

Reference numeral 1 denotes a rotary drum type electrophotographic photosensitive member (photosensitive drum) which is repeatedly used as a first image bearing member.
And is rotationally driven in the clockwise direction indicated by the arrow at a predetermined peripheral speed (process speed).

In the course of rotation, the electrophotographic photosensitive member 1 is uniformly charged to a predetermined polarity and potential by the primary charging means (charging roller) 2. Reference numeral 32 is a power source for the primary charging means 2, and here, although AC is superimposed on DC and applied, DC alone may be used.

Next, the exposure means 3 (color separation / condensation exposure optical system for color original image, scanning exposure system by laser scanner for outputting laser beam modulated corresponding to time series electric digital pixel signal of image information, etc.) Upon exposure to light, an electrostatic latent image corresponding to the first color component image (for example, yellow color component image) of the target color image is formed.

Next, the electrostatic latent image is developed by the first developing means (yellow developing device 41) with the yellow toner Y which is the first color. At this time, second to fourth developing means (magenta color developing device 42, cyan color developing device 4
3, each developing device of the black color developing device 44) is in the operation-off state and does not act on the electrophotographic photosensitive member 1.
The color yellow toner image is not affected by the second to fourth developing devices.

The intermediate transfer belt 5 is rotationally driven in the clockwise direction at the same peripheral speed as the electrophotographic photosensitive member 1.

During the process in which the yellow toner image of the first color formed and carried on the electrophotographic photosensitive member 1 passes through the contact portion between the electrophotographic photosensitive member 1 and the intermediate belt 5, a roller-shaped primary transfer means is provided. By the electric field formed by the primary transfer bias applied from the (primary transfer roller) 6 to the intermediate transfer belt 5, primary transfer is sequentially performed on the outer peripheral surface of the intermediate transfer belt 5.

The surface of the electrophotographic photosensitive member 1 on which the transfer of the yellow toner image of the first color corresponding to the intermediate transfer belt 5 has been completed is cleaned by the electrophotographic photosensitive member cleaning means 13.

Similarly, the magenta toner image of the second color, the cyan toner image of the third color, and the black toner image of the fourth color are sequentially transferred onto the intermediate transfer belt 5 in a superimposed manner to correspond to the intended color image. The combined color toner image is formed.

Reference numeral 7 denotes a roller-shaped secondary transfer means (secondary transfer roller), which is supported in parallel with the drive roller 8 and is disposed on the lower surface of the intermediate transfer belt 5 in a separable state.

The primary transfer bias for sequentially superposing and transferring the toner images of the first to fourth colors from the electrophotographic photosensitive member 1 to the intermediate transfer belt 5 is applied from the bias power source 30 with the polarity (+) opposite to that of the toner. To be done. The applied voltage is +10, for example.
It is in the range of 0V to 2kV.

In the primary transfer process of the toner images of the first to third colors from the electrophotographic photosensitive member 1 to the intermediate transfer belt 5,
The secondary transfer means 7 can be separated from the intermediate transfer belt 5.

The transfer of the composite color toner image transferred onto the intermediate transfer belt 5 onto the transfer material P, which is the second image carrier, is performed when the secondary transfer means 7 is brought into contact with the intermediate transfer belt 5. The transfer material P is fed from the paper feed roller 11 through the transfer material guide 10 to the contact portion between the intermediate transfer belt 5 and the secondary transfer means 7 at a predetermined timing, and the secondary transfer bias is supplied from the bias power supply 31. It is applied to the secondary transfer means 7. By this secondary transfer bias, the composite color toner image is secondarily transferred from the intermediate transfer belt 5 to the transfer material P which is the second image carrier. The transfer material P that has received the transfer of the toner image is introduced into the fixing unit 15 and is heat-fixed.

After the transfer of the image onto the transfer material P, the charge applying means 9 arranged so as to be separable from the intermediate transfer belt 5 is brought into contact with the intermediate transfer belt 5 to apply a bias having a polarity opposite to that of the electrophotographic photosensitive member 1. As a result, the transfer residual toner that has not been transferred to the transfer material P and remains on the intermediate transfer belt 5 is given a charge of the opposite polarity to that at the time of primary transfer. 33 is a bias power supply. Here, alternating current is superimposed on direct current and applied.

The transfer residual toner charged to the opposite polarity to that at the time of the primary transfer is electrostatically transferred to the electrophotographic photosensitive member 1 at the contact portion with the electrophotographic photosensitive member 1 and in the vicinity thereof, so that an intermediate The transfer belt is cleaned. Since this step can be performed at the same time as the primary transfer, there is no reduction in throughput.

Next, the intermediate transfer belt-electrophotographic photosensitive member integrated cartridge of the present invention will be described.

As shown in FIG. 2, the process cartridge of the present invention integrally supports at least the electrophotographic photosensitive member 1, the intermediate transfer belt 5, the primary transfer means 6, and the charge giving means 9. It is configured so that it can be easily attached to and detached from the main body of the electrophotographic apparatus.

Further, one or more of the electrophotographic photosensitive member cleaning means, the primary charging means, the waste toner container, and the like included in the electrophotographic apparatus are integrated with the intermediate transfer belt-electrophotographic photosensitive member. In addition, the electrophotographic apparatus is provided with means such as the electrophotographic photosensitive member cleaning means, the primary charging means, and the waste toner container when the process cartridge is further attached to the electrophotographic apparatus. Good.

The cleaning mechanism of the intermediate transfer belt of the present invention is a mechanism necessary for charging the transfer residual toner to the polarity opposite to that of the primary transfer and returning it to the electrophotographic photoreceptor at the temporary transfer portion, as described above. In this figure, a charge applying unit (intermediate transfer belt cleaning roller) 9 made of an elastic body of medium resistance is used.
Are equipped with.

On the other hand, the cleaning of the electrophotographic photoconductor is
Blade cleaning using an elastic blade is preferable. A waste toner container (not shown) is also integrated in the process cartridge shown in this figure, and the transfer residual toner of both the intermediate transfer belt and the electrophotographic photosensitive member is discarded at the same time when the process cartridge is replaced. Contributes to improvement.

The intermediate transfer belt is stretched by two rollers 8 and 12 to reduce the number of parts and reduce the size. Here, 8 is a driving roller, and at the same time is an opposing roller of the charge applying means (intermediate transfer belt cleaning roller).

The tension roller 12 that rotates by following the intermediate transfer belt has a mechanism for sliding.
It is pressed against the direction of the arrow by a compression spring to give tension to the intermediate transfer belt. The slide width is about 1 to 5 mm, and the total pressure of the springs is about 5 to 100N.

Further, the electrophotographic photosensitive member 1 and the driving roller 8
Has a coupling (not shown), and the rotational driving force is transmitted from the main body.

The methods for measuring various physical properties according to the present invention are shown below.

<Measurement Method of Elastic Modulus and Elongation at Break> A sample was cut out from the intermediate transfer belt in a circumferential direction with a width of 20 mm and a length of 100 mm, the thickness was measured, and then a tensile tester (Tensilon RTC-1250A manufactured by Orientec Co., Ltd.) was used.
Attach to. The thickness is the average of 5 points in the sample. A tensile test was conducted with a measurement interval of 50 mm and a test speed of 5 mm / min, the elongation and stress were recorded by a recorder, the stress when the elongation was 0.5% and 0.6% was read, and the elastic modulus was calculated by the following formula. To calculate.

This measurement was carried out 5 times, and the averaged value is the elastic modulus of the present invention.

Modulus of elasticity = (f2-f1) / (20 × t) × 1000 [MPa] (In the formula, f1 is a stress of 0.5% elongation [N], and f2 is 0.
6% elongation stress [N], t indicates the thickness of the sample [mm]. ) The elongation at break is the displacement from the start of measurement at the point where the test piece was pulled by pulling a test piece using the same device with the same sample shape, except that the pulling speed in the elastic modulus measuring method was changed to 50 mm / min. Record L [mm] and calculate by the following formula.

This measurement was carried out 5 times, and the average value is the breaking elongation of the present invention.

Elongation at break = L / 50 × 100 [%] <Measurement of Surface Roughness> According to JISB0601.

<Volume Resistance Measurement Method> As a measuring device, an ultra-high resistance meter R8340A (manufactured by Advantest) is used for the resistance meter, and an ultra-high resistance sample box TR42 (manufactured by Advantest) is used for the sample box. But the main electrode is 25m in diameter
m, guard ring electrode 41 mm inside diameter, 49 mm outside diameter
And

The sample is manufactured as follows.

First, the intermediate transfer belt is cut into a circular shape having a diameter of 56 mm with a punching machine or a sharp blade. On one surface of the cut out circular piece, an electrode is provided on the entire surface by a Pt-Pd vapor deposition film, and on the other surface, a main electrode having a diameter of 25 mm and a guard electrode having an inner diameter of 38 mm and an outer diameter of 50 mm are provided by the Pt-Pd vapor deposition film. The Pt-Pd vapor deposition film is obtained by performing vapor deposition operation for 2 minutes with mild sputter E1030 (manufactured by Hitachi Ltd.). A sample for which the vapor deposition operation has been completed is used as a measurement sample.

The measurement atmosphere was 23 ° C./55% RH,
The measurement sample is left in the same atmosphere for 12 hours or more in advance. Measurement is discharge 10 seconds, charge 3
The measurement is performed at an applied voltage of 100 V with 0 seconds and 30 seconds as a measure.

<Thickness Measuring Method> The thickness unevenness of the intermediate transfer belt of the present invention is measured with a dial gauge having a minimum value of 1 μm at 50 mm from both ends of the belt and at four points at equal intervals in the circumferential direction at the center. However, it is a value obtained by averaging 12 points in total for each intermediate transfer belt.

[0111]

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

First, the process cartridges used in Examples and Comparative Examples will be described.

FIG. 5 shows a schematic structure of a process cartridge constituted by connecting an electrophotographic photosensitive member unit having an electrophotographic photosensitive member and an intermediate transfer belt unit having an intermediate transfer belt.

6 and 7 show schematic structures of the intermediate transfer belt unit and the electrophotographic photosensitive member unit, respectively.

The frame structure is roughly divided into two.

The electrophotographic photosensitive member frame 59, which is integrally formed with the waste toner container 52 shown in FIG. 7, has the electrophotographic photosensitive member 1, the charging roller 2, the cleaning blade 53, the screw 54, and the drum shutter 55 as main components. The electrophotographic photoconductor unit 50 and the intermediary transfer belt frame 45 shown in FIG. 6 in which the intermediary transfer belt 5 is suspended and stretched by the driving roller 8 and the driven roller 12, and the electrophotographic photoconductor 1 faces the intermediary transfer. It is divided into a primary transfer roller 58 inside the belt, and an intermediate transfer belt unit 51 in which a drive roller 8 is also provided with a charge applying means (intermediate transfer belt cleaning roller) 9.

In these two units, the projections 71 provided at both the left and right ends of the electrophotographic photosensitive member frame 59 are inserted into the positioning holes 72 provided in the intermediate transfer belt frame 45, respectively, while the electrophotographic photosensitive member is provided. Frame 59
The claw 73 of the snap-fit type hook provided at the center of the width direction of the
Are fitted and connected.

Here, the positioning hole 72 and the lock hole 74 provided in the intermediate transfer frame 45 are larger than the projection 71 and the hook claw 73 provided in the electrophotographic photosensitive member frame 59 by a predetermined amount. The electrophotographic photosensitive member unit 50 and the intermediate transfer belt unit 51 are opened.
Between them, a predetermined amount of relative position movement is possible.

The positioning hole 72 has a taper portion 72a.
Is provided for easy attachment and detachment.

In FIG. 7, the electrophotographic photosensitive member unit 5
Press the hook claw 73 of 0 to press the intermediate transfer belt unit 51.
From the lock hole 74 of the electrophotographic photoreceptor unit 50.
When rotated, the electrophotographic photosensitive member unit and the intermediate transfer belt unit can be divided as shown in FIGS.

At the time of connection, contrary to the above, the projection 71 of the electrophotographic photosensitive member unit 50 is inserted into the positioning hole 72 of the intermediate transfer belt unit 51, and is rotated in the opposite direction to that at the time of removal to hook. The two units are connected by pushing the claw 73 into the lock hole 74.

FIG. 8 shows how the process cartridge of the present invention is attached to and detached from the electrophotographic apparatus.

Just by opening the upper lid 60 of the main body of the electrophotographic apparatus, the process cartridge can be attached / detached as easily as the conventional black and white laser beam printer, and maintenance such as jam processing and process cartridge replacement can be easily performed.

(Example 1) PVdF (polyvinylidene fluoride) 100 parts Polyether-containing antistatic resin 14 parts With the above composition, the antistatic resin has a greater elongation than PVdF and the two materials are not completely compatible with each other. Was selected. This material was melt-kneaded at 210 ° C. with a twin-screw extruder to mix each material, and extruded with a strand having a diameter of about 2 mm to cut into pellets. This is used as a forming raw material 1.

Next, in the manufacturing apparatus shown in FIG. 3, the molding die 103 was a single-layer annular die having a gap diameter of 100 mm. The width of the gap of the annular die was 0.8 mm.

The molding raw material 1 which had been sufficiently heated and dried was charged into the material hopper 102 of this manufacturing apparatus, heated and melted, and extruded into a cylindrical shape from the die at 210 ° C. An external cooling ring 105 is installed around the die to cool the extruded film by blowing air from the surroundings.

Air is sucked into the extruded tubular film through the gas introduction passage 104 to have a diameter of 140 m.
After expanding and expanding to m, it was continuously taken up by a take-up device at a constant speed. The introduction of air is stopped when the diameter reaches a desired value.

Further, the tubular film is cut by the cutting device 108 following the pinch roller.

After the thickness was stabilized, six tubular films were formed by cutting into a length of 310 mm.

The tubular film was subjected to adjustment of size and surface smoothness and removal of folds by using a set of cylindrical dies made of metals having different coefficients of thermal expansion.

An inner mold having a high coefficient of thermal expansion is covered with the tubular film, and the inner mold is inserted into an outer mold whose inner surface is smoothed and heated at 170 ° C. for 20 minutes.

After cooling, it was removed from the cylinder and the end portion was cut to prepare six intermediate transfer belts having a diameter of 140 mm.
A meandering prevention member was attached to one of these for image confirmation.

<Measurement of Physical Properties> Of the intermediate transfer belt,
Five pieces were left in an environment of 23 ° C./55% RH for 3 days, and physical properties were measured.

First, the elastic modulus measurement samples were cut out one by one from one intermediate transfer belt, measured according to the above measuring method, and averaged at 5 points. As a result, the elastic modulus of the intermediate transfer belt 1 when stretched from 0.5% to 0.6% is 81.
It was 5 MPa.

A sample was taken in the same manner and each measurement was carried out. The elongation at break was 20% and the surface roughness Ra was 0.03.
μm, thickness 102 μm, volume resistivity 7.8 × 10 ¹⁰ Ω
・ It was cm.

<Image Evaluation> Of the six intermediate transfer belts prepared as described above, the remaining one not used for the physical property measurement was incorporated into the intermediate transfer belt-electrophotographic photosensitive member integrated cartridge having the above-mentioned configuration. . At this time, the spring pressure of the tension roller is 20 N in total on the left and right, the slide amount is 2.5 mm, the diameter of the tension roller and the drive roller is 28 mm, and the diameter of the electrophotographic photosensitive member is 47 mm.
A photosensitive drum having a photosensitive layer formed on the aluminum cylinder of No. 3 was used.

Then, as an accelerated test of leaving for a long time, this process cartridge was left in a high temperature environment of 40 ° C. for 14 days. Then, set in the electrophotographic apparatus shown in FIG. 1 from the left 12 h at 23 ℃ / 55% RH environment, were printed test of a full-color image to 80 g / m ² paper under the environment.

The exposure means used at this time is 600d.
It is a digital exposure means for forming an electrostatic latent image on the surface of an electrophotographic photosensitive member by a pi digital (laser) system.

When the obtained image was visually evaluated, a good full-color image free from problems such as color misregistration, color unevenness and transfer omission was obtained.

Continuously 5000 times at a speed of 4 sheets per minute
When a durable print test was performed on one sheet and the image was evaluated in the same manner, a good image similar to the initial stage was obtained, and the process cartridge integrally supporting the intermediate transfer belt and the electrophotographic photosensitive member prepared as described above. Was confirmed to have good performance.

The results are shown in Table 1.

(Example 2) Six intermediate transfer belts were molded in the same manner as in Example 1 except that the compounding ratio was changed as follows.

PVdF 100 parts Polyether-containing antistatic resin 8 parts Sulfonate type surfactant 4 parts This intermediate transfer belt was subjected to the same physical property measurement and image printing test as in Example 1. As a result, the elastic modulus of the intermediate transfer belt at 0.5% to 0.6% elongation is 585 MPa, the breaking elongation is 680%, the surface roughness Ra is 0.04 μm, the thickness is 100 μm, and the volume resistivity is 8 It was 0.3 × 10 ⁹ Ω · cm.

The result of the image test by printing using the process cartridge integrally supporting the intermediate transfer belt and the electrophotographic photosensitive member was as good as in Example 1.

The results are shown in Table 1.

Example 3 An intermediate transfer belt was prepared in the same manner as in Example 1 except that the compounding ratio was changed as follows, and the kneading and molding according to the resin and the mold heating temperature were both raised to 260 ° C. Six were manufactured.

Polycarbonate 100 parts Inorganic metal salt 1.5 parts This intermediate transfer belt was subjected to measurement of physical properties and image print test in the same manner as in Example 1. As a result, this intermediate transfer belt has an elastic modulus of 2300 MPa when stretched from 0.5% to 0.6%, an elongation at break of 56%, a surface roughness Ra of 0.08 μm, a thickness of 100 μm, and a volume resistivity of 2 It was 0.2 × 10 ¹² Ω · cm.

The result of the image test by printing using the process cartridge integrally supporting the intermediate transfer belt and the electrophotographic photosensitive member was as good as in Example 1.

The results are shown in Table 1.

Example 4 The compounding ratio was changed as follows, and the kneading and molding according to the resin, and the mold heating temperature were raised to 260 ° C., respectively. Moreover, Example 1 was changed except that the inner surface roughness of the outer mold was changed to be slightly rough in the mold processing.
Six intermediate transfer belts were manufactured in the same manner as in.

Polycarbonate 100 parts Conductive carbon black 25 parts This intermediate transfer belt was subjected to measurement of physical properties and image print test in the same manner as in Example 1. As a result, this intermediate transfer belt has an elastic modulus of 2500 MPa when stretched from 0.5% to 0.6%, an elongation at break of 38%, a surface roughness Ra of 0.5 μm, a thickness of 108 μm, and a volume resistivity of 2 ．
It was 5 × 10 ⁸ Ω · cm.

Further, as a result of the image test by the printing using the process cartridge which integrally supports the intermediate transfer belt and the electrophotographic photosensitive member, although the image was slightly unclear, it was judged to be practical.

The results are shown in Table 1.

Comparative Example 1 Six intermediate transfer belts were produced in the same manner as in Example 1 except that the compounding ratio was changed as follows.

PVdF 100 parts Polyether-containing antistatic resin 30 parts Fluorosurfactant 4 parts This intermediate transfer belt was subjected to measurement of physical properties and image print test in the same manner as in Example 1. As a result, this intermediate transfer belt 2 has an elastic modulus of 450 MPa when stretched from 0.5% to 0.6%, an elongation at break of 880%, a surface roughness Ra of 0.04 μm, a thickness of 99 μm, and a volume resistivity. It was 3.1 × 10 ⁹ Ω · cm.

An image test by printing was conducted using a process cartridge integrally supporting the intermediate transfer belt and the electrophotographic photosensitive member. As a result, color misregistration was recognized from the initial stage, and it became more remarkable after the durability test. It turned out to be unsuitable for.

The results are shown in Table 1.

(Comparative Example 2) Six intermediate transfer belts were produced in the same manner as in Example 1 except that the compounding ratio was changed as follows and no processing was performed using a mold.

PVdF 100 parts Conductive carbon black 18 parts Metal oxide particles 50 parts With respect to this intermediate transfer belt, the physical properties were measured and the image print test was carried out in the same manner as in Example 1. As a result, this intermediate transfer belt has an elastic modulus of 1500 MPa when stretched from 0.5% to 0.6%, a breaking elongation of 2.5%, a surface roughness Ra of 1.1 μm, a thickness of 108 μm, and a volume resistance. The rate was 1.2 × 10 ⁸ Ω · cm.

Further, as a result of the image test by the printing using the process cartridge which integrally supports the intermediate transfer belt and the electrophotographic photosensitive member, the image is rugged from the initial stage, and the intermediate transfer belt is not properly cleaned. Was.

Further, a durability print test was conducted, and it was judged that practical use was impossible because a crack was generated from the end portion of the belt in the vicinity of 3,600 sheets.

The results are shown in Table 1.

[0163]

[Table 1]

[0164]

As described above, according to the present invention, a process cartridge which can be easily maintained, can be downsized and cost reduced, and can obtain a good image even during long-term transportation or storage, An intermediate transfer belt for a process cartridge and an electrophotographic apparatus having the process cartridge can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an electrophotographic apparatus using an intermediate transfer belt-electrophotographic photosensitive member integrated cartridge of the present invention.

FIG. 2 is a schematic configuration diagram of a process cartridge of the present invention.

FIG. 3 is a diagram showing an example of an apparatus for manufacturing an intermediate transfer belt. (Single layer)

FIG. 4 is a diagram showing an example of an apparatus for manufacturing an intermediate transfer belt. (2 layers)

FIG. 5 is a schematic configuration diagram of a process cartridge used in Examples and Comparative Examples and configured by connecting an electrophotographic photoreceptor unit and an intermediate transfer belt unit.

FIG. 6 is a schematic configuration diagram of an intermediate transfer belt unit.

FIG. 7 is a schematic configuration diagram of an electrophotographic photosensitive member unit.

FIG. 8 is a diagram showing a state when the process cartridge of the present invention is attached to and detached from an electrophotographic apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Primary charging means (charging roller) 3 Exposure means 41 First developing means (yellow color developing device) 42 Second developing means (magenta color developing device) 43 Third developing means (cyan color developing) 44) Fourth developing means (black developing device) 5 Intermediate transfer belt 6 Primary transfer means (primary transfer roller) 7 Secondary transfer means (secondary transfer roller) 8 Driving roller 9 Charge applying means (intermediate transfer belt cleaning) Roller) 10 Transfer material guide 11 Paper feed roller 12 Tension roller (following roller) 13 Electrophotographic photosensitive member cleaning means 15 Fixing means 30 (Primary transfer) Bias power supply 31 (Secondary transfer) Bias power supply 32 Primary charging means power supply 33 Bias Power source P Transfer material 45 Intermediate transfer belt frame 50 Electrophotographic photoreceptor unit 51 Intermediate transfer belt Unit 52 Waste toner container 53 Cleaning blade 54 Screw 55 Drum shutter 58 Primary transfer roller 59 Electrophotographic photosensitive member frame 60 Electrophotographic apparatus body upper lid 71 Protrusion 72 Positioning hole 72a Tapered portion 73 Hook claw 74 Lock hole 100 Extruder 101 Extruder 102 Hopper 103 Annular Die 104 Gas Inlet 105 External Cooling Ring 106 Stabilizer 107 Pinch Roller 108 Cutting Device 110 Cylindrical Film

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // B29L 29:00 G03G 21/00 312 (72) Inventor Tsunenori Ashina 3 chome Shimomaruko, Ota-ku, Tokyo No. 30-2 Canon Inc. (72) Inventor Atsushi Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Hidekazu Matsuda 3-30-2 Shimomaruko, Ota-ku, Tokyo In Canon Inc. (72) Inventor Hiroyuki Kobayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H134 GA01 GA06 GB02 HA01 HA12 HA16 HD01 KB02 KG03 KG04 KG07 KG08 KH01 KH03 KH10 KH16 2H171 FA02 FA03 FA07 FA09 FA10 FA11 FA13 FA15 FA17 FA24 FA25 FA26 GA01 GA03 GA04 GA11 GA12 JA02 JA03 JA04 JA05 JA06 JA08 JA10 JA23 JA26 JA28 JA29 JA30 JA31 JA48 KA06 KA27 P A04 PA08 PA14 PA19 QA02 QA05 QA08 QA24 QA29 QB03 QB10 QB15 QB34 QC03 QC22 QC24 TA04 TA07 TA17 TB04 TB13 UA03 UA12 UA14 UA28 2H200 FA12 GA23 GA31 GA44 GA47 GA01 GA12 GA03 J01 JC17 J01 JC17 J12C01 JB17 HB12 HB12 JB03 H01 MA02 MB04 MC01 MC03 MC06 NA02 NA06 4F210 AA16 AA32 AB13 AG16 AR12 QA01 QK01 QK05

Claims (25)

[Claims] 1. A process cartridge detachably mountable to an electrophotographic apparatus main body, comprising: an electrophotographic photosensitive member for carrying a toner image; and an intermediate transfer belt having a contact portion with the electrophotographic photosensitive member. A primary transfer means for primarily transferring an image of the toner from the electrophotographic photosensitive member to the intermediate transfer belt at the contact portion; and toner on the intermediate transfer belt at the corresponding contact portion of the electrophotographic photosensitive member. In order to clean the intermediate transfer belt by returning to the above, integrally supporting a charge giving means for giving the toner on the intermediate transfer belt a charge having a polarity opposite to the polarity of the toner at the time of primary transfer, The intermediate transfer belt has an elastic modulus of 500 MPa to 4000 MPa when stretched from 0.5% to 0.6% in the circumferential direction, a breaking elongation of 5% to 850% in the circumferential direction, and a surface roughness. Ra is 1 A process cartridge, wherein m or less. 2. The process cartridge according to claim 1, further comprising an electrophotographic photosensitive member cleaning means for cleaning the electrophotographic photosensitive member. 3. An electrophotographic photosensitive member unit having the electrophotographic photosensitive member and an intermediate transfer belt unit having the intermediate transfer belt are separable, and the electrophotographic photosensitive member unit and the intermediate transfer belt unit are connected to each other. The process cartridge according to claim 1 or 2, further comprising a connecting means for connecting. 4. The volume resistivity of the intermediate transfer belt is 1 ×
The process cartridge according to any one of claims 1 to 3, wherein the process cartridge has a thickness of 10 ⁶ Ω · cm to 8 × 10 ¹³ Ω · cm and a thickness of the intermediate transfer belt of 40 μm to 300 μm. 5. An intermediate transfer belt is melt-extruded from an annular die to obtain a tubular film, and a melt-extruding step is performed. Gas is injected into the tubular film melt-extruded by the melt-extruding step to reduce the internal volume. A diameter control step of adjusting and controlling the diameter of the tubular film, and a film extruded by the melt extrusion step until the tubular film whose diameter is controlled by the diameter control step is cooled and solidified. Intermediate having a tubular film forming step of forming a tubular film having a diameter larger than that of the annular die without using a supporting member, and a cutting step of cutting the tubular film formed by the tubular film forming step. The process cartridge according to claim 1, wherein the process cartridge is an intermediate transfer belt manufactured by a transfer belt manufacturing method. 6. The intermediate transfer belt is stretched by rollers, and at least one of the rollers is 1 mm.
The process cartridge according to any one of claims 1 to 5, which has a function of sliding as described above and applying a force of 5 N or more to the intermediate transfer belt. 7. The process cartridge according to claim 1, wherein the intermediate transfer belt is stretched by two rollers. 8. The process cartridge according to claim 1, wherein the electrophotographic photosensitive member has a drum shape. 9. An electrophotographic photosensitive member for carrying a toner image, a charging unit for charging the electrophotographic photosensitive member, and an electrostatic latent image on the electrophotographic photosensitive member charged by the charging unit. An exposure unit for forming the image, a developing unit for developing the electrostatic latent image of the electrophotographic photosensitive member formed by the exposure unit with toner, and forming an image of the toner on the electrophotographic photosensitive member; An intermediate transfer belt having a contact portion with the electrophotographic photoreceptor for secondary transfer of the toner image transferred after the toner image is primarily transferred from the photoreceptor to the transfer material, and the contact portion At the primary transfer means for primarily transferring the image of the toner from the electrophotographic photosensitive member to the intermediate transfer belt, and returning the toner on the intermediate transfer belt to the electrophotographic photosensitive member at the contact portion. Clean the intermediate transfer belt Charging means for applying a charge having a polarity opposite to that of the toner at the time of the primary transfer to the toner on the intermediate transfer belt, and an electrophotographic photosensitive member for cleaning the electrophotographic photosensitive member. A body cleaning means, at least the electrophotographic photosensitive member, the intermediate transfer belt,
Integrally supporting the primary transfer means and the charge applying means,
The electrophotographic apparatus has a detachable process cartridge, and the intermediate transfer belt has an elastic modulus of 500 MPa to 4000 MPa when stretched from 0.5% to 0.6% in the circumferential direction. Has an elongation at break of 5% to 850% and a surface roughness Ra of 1 μm or less. 10. The electrophotographic apparatus according to claim 9, wherein the process cartridge further supports electrophotographic photosensitive member cleaning means for cleaning the electrophotographic photosensitive member. 11. The process cartridge is separable into an electrophotographic photosensitive member unit having the electrophotographic photosensitive member and an intermediate transfer belt unit having the intermediate transfer belt, and the electrophotographic photosensitive member unit and the intermediate transfer belt. The electrophotographic apparatus according to claim 9, further comprising a connecting unit that connects the belt unit. 12. The volume resistivity of the intermediate transfer belt is 1
The electrophotographic apparatus according to claim 9, wherein the electrophotographic apparatus has a thickness of × 10 ⁶ Ω · cm to 8 × 10 ¹³ Ω · cm and a thickness of the intermediate transfer belt of 40 μm to 300 μm. 13. An intermediate transfer belt is melt-extruded from an annular die to obtain a tubular film, and a gas is injected into the tubular film melt-extruded by the melt-extruding step to reduce the internal volume. A diameter control step of adjusting and controlling the diameter of the tubular film, and a film extruded by the melt extrusion step until the tubular film whose diameter is controlled by the diameter control step is cooled and solidified. Intermediate having a tubular film forming step of forming a tubular film having a diameter larger than that of the annular die without using a supporting member, and a cutting step of cutting the tubular film formed by the tubular film forming step. An intermediate transfer belt manufactured by a transfer belt manufacturing method.
The electrophotographic apparatus according to any one of 1. 14. The intermediate transfer belt is stretched by rollers, and at least one of the rollers is 1 m.
14. The electrophotographic apparatus according to claim 9, which has a function of sliding by m or more and applying a force of 5 N or more to the intermediate transfer belt. 15. The electrophotographic apparatus according to claim 9, wherein the intermediate transfer belt is stretched around two rollers. 16. The electrophotographic apparatus according to claim 9, wherein the electrophotographic photosensitive member has a drum shape. 17. A charging step of charging an electrophotographic photosensitive member, an exposure step of forming an electrostatic latent image on the electrophotographic photosensitive member charged in the charging step, and an electrophotographic photosensitive member formed in the exposure step. Developing the electrostatic latent image of with a toner to form an image of the toner on the electrophotographic photoreceptor, and the image of the toner formed by the developing step by the primary transfer means from the electrophotographic photoreceptor. A primary transfer step of primary transfer to an intermediate transfer belt having a contact portion with the electrophotographic photoreceptor, and a secondary transfer step of secondary transfer of the toner image primarily transferred in the primary transfer step to a transfer material. A charge applying step of applying a charge having a polarity opposite to the polarity of the toner at the primary transfer step to the toner on the intermediate transfer belt by the charge applying means, and the toner on the intermediate transfer belt at the contact portion. Return to the electrophotographic photoreceptor An image forming method comprising: an intermediate transfer belt cleaning step of cleaning the intermediate transfer belt with an electrophotographic photosensitive member; and an electrophotographic photosensitive member cleaning step of cleaning the electrophotographic photosensitive member, comprising at least the electrophotographic photosensitive member and the intermediate transfer member. A belt,
Integrally supporting the primary transfer means and the charge applying means,
An image forming method using an electrophotographic apparatus having a detachable process cartridge in an electrophotographic apparatus main body, wherein the intermediate transfer belt is stretched from 0.5% to 0.6% in a circumferential direction. An image forming method characterized in that the elastic modulus is 500 MPa to 4000 MPa, the breaking elongation in the circumferential direction is 5% to 850%, and the surface roughness Ra is 1 μm or less. 18. The image forming method according to claim 17, wherein the process cartridge further supports an electrophotographic photosensitive member cleaning unit for cleaning the electrophotographic photosensitive member. 19. The process cartridge is separable into an electrophotographic photosensitive member unit having the electrophotographic photosensitive member and an intermediate transfer belt unit having the intermediate transfer belt, and the electrophotographic photosensitive member unit and the intermediate transfer belt. 18. A connecting means for connecting with a belt unit.
Or the image forming method according to item 18. 20. The volume resistivity of the intermediate transfer belt is 1
The image forming method according to any one of claims 17 to 19, wherein the thickness is from 10 ⁶ Ω · cm to 8 × 10 ¹³ Ω · cm, and the thickness of the intermediate transfer belt is from 40 μm to 300 μm. 21. An intermediate transfer belt is melt-extruded from an annular die to obtain a tubular film, and a gas is injected into the tubular film melt-extruded by the melt-extruding step to increase the internal volume. A diameter control step of adjusting and controlling the diameter of the tubular film, and a film extruded by the melt extrusion step until the tubular film whose diameter is controlled by the diameter control step is cooled and solidified. Intermediate having a tubular film forming step of forming a tubular film having a diameter larger than that of the annular die without using a supporting member, and a cutting step of cutting the tubular film formed by the tubular film forming step. An intermediate transfer belt manufactured by a transfer belt manufacturing method.
The image forming method according to any one of 0. 22. The intermediate transfer belt is stretched by rollers, and at least one of the rollers is 1 m.
22. The image forming method according to claim 17, wherein an electrophotographic apparatus having a function of sliding by m or more and applying a force of 5 N or more to the intermediate transfer belt is used. 23. An electrophotographic apparatus in which the intermediate transfer belt is stretched by two rollers is used.
23. The image forming method according to any one of 22. 24. The image forming method according to claim 17, wherein the electrophotographic photosensitive member has a drum shape. 25. An intermediate transfer belt for use in the process cartridge according to claim 1.