JPH1039647A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of problems caused by the structure such as the cracking, partial broken, separation or the like, of an intermediate transfer member, and to improve the transfer efficiency, by specifying the construction of a surface layer of the intermediate transfer member. SOLUTION: In an image forming device, an intermediate transfer member has a surface layer on an elastic layer, the surface layer includes 10-80weight%, to the total solid matter in the surface layer, of the lubricating particles, the distribution of the lubricating particles of the surface layer is within an extent represented by 3.0 >= amount of lubricating particles on surface of surface layer/amount of those inside of surface layer >=0.8, and the surface roughness of the intermediate transfer member is 0.1-3μm. The suffient amount of lubricating particles is exposed to the surface of the intermediate transfer member, and the distribution and the addition amount of the lubricating particles are adjusted to prevent the excess amount of the lubricating particles inside of the surface layer and on an interface kept into contact with the elastic layer, so that the high image quality, surface mold releasing characteristic, strength of the surface layer and adhesion can be obtained. The durability of the intermediate transfer member can be improved with the comparatively low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic method, and more particularly, to a method in which a toner image formed on a first image carrier is temporarily transferred onto an intermediate transfer member and then transferred to a second image carrier. The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile that obtains an image formed product by further transferring the image on an image carrier.

[0002]

2. Description of the Related Art An image forming apparatus using an intermediate transfer member includes:
A color image forming apparatus, a multi-color image forming apparatus, or a color image forming apparatus that sequentially transfers a plurality of component color images of color image information or multi-color image information and outputs an image formed product by combining and reproducing a color image or a multi-color image. It is effective as an image forming apparatus having a forming function and a multi-color image forming function, and can obtain an image without overlapping deviation (color deviation) of each component color image.

FIG. 1 is a schematic view showing an example of an image forming apparatus which is a transfer apparatus using an intermediate transfer member having a roller shape.

FIG. 1 shows a color image forming apparatus (copier or laser beam printer) using an electrophotographic process. Medium resistance elastic roller 20 as an intermediate transfer member
You are using

Reference numeral 1 denotes a rotating drum type electrophotographic photosensitive member (hereinafter, referred to as a photosensitive drum) which is repeatedly used as a first image carrier, and has a predetermined peripheral speed (process speed) in a clockwise direction indicated by an arrow. It is driven to rotate.

In the course of rotation, the photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by a primary charger (corona discharger) 2, and then image exposure means (not shown) for color separation and color separation of a color original image. An imaging exposure optical system, a scanning exposure system using a laser scanner that outputs a laser beam modulated according to a time-series electric digital pixel signal of image information, etc.)
, An electrostatic latent image corresponding to a first color component image (for example, a magenta component image) of a target color image is formed.

Next, the electrostatic latent image is transferred to the first developing device 41.
(Magenta developing device) is developed with magenta toner M as the first color. At this time, the second to fourth developing devices 42,
43,44 (cyan, yellow, black developing units)
Is turned off and does not act on the photosensitive drum 1,
The first color magenta toner image is not affected by the second to fourth developing units 42 to 44.

The intermediate transfer member 20 is rotated at the same peripheral speed as the photosensitive drum 1 in the counterclockwise direction indicated by the arrow.

The intermediate transfer member 20 of this embodiment comprises a pipe-shaped core 21 and an elastic layer 22 formed on the outer peripheral surface thereof.

[0010] The first type formed and supported on the photosensitive drum 1
In the process in which the magenta toner image of color passes through the nip portion between the photosensitive drum 1 and the intermediate transfer body 20, an electric field formed by a transfer bias applied to the intermediate transfer body 20 causes
The intermediate transfer is sequentially performed on the outer peripheral surface of the intermediate transfer body 20. This transfer process from the photosensitive drum to the intermediate transfer member is called primary transfer.

After the transfer of the first color magenta toner image corresponding to the intermediate transfer member 20, the surface of the photosensitive drum 1 is cleaned by the cleaning device 14.

Similarly, a second color cyan toner image, a third color yellow toner image, and a fourth color black toner image are sequentially superimposed and transferred onto the intermediate transfer body 20 to form a composite color image corresponding to the target color image. A toner image is formed.

Reference numeral 25 denotes a transfer roller, which is provided in parallel with the intermediate transfer member 20 and in contact with the lower surface thereof.

The first transfer from the photosensitive drum 1 to the intermediate transfer body 20
The primary transfer bias for the sequential superimposed transfer of the toner images of the fourth to fourth colors has a polarity (+) opposite to that of the toner and a bias power source 6
Applied from 1. The applied voltage is, for example, +2 kV to +
The range is 5 kV.

First transfer from the photosensitive drum 1 to the intermediate transfer member 20
The transfer roller 25 and the intermediate transfer member cleaner 35 can be separated from the intermediate transfer member 20 in the step of sequentially transferring the toner images of the fourth to fourth colors.

The transfer of the composite color toner image superimposed and transferred onto the intermediate transfer member 20 onto a transfer material 24 as a second image carrier is performed while the transfer roller 25 is brought into contact with the intermediate transfer member 20 and supplied. The transfer material 2 is transferred from the paper cassette 9 to the contact nip between the intermediate transfer body 20 and the transfer roller 25 at a predetermined timing.
4 is fed, and at the same time, a secondary transfer bias is applied to the transfer roller 25 from the bias power supply 29. This step in which the composite color toner image is transferred from the intermediate transfer body 20 to the transfer material 24 as the second image carrier by the secondary transfer bias is called secondary transfer. The transfer material 24 to which the toner image has been transferred is introduced into the fixing device 15 and is fixed by heating.

After the image transfer to the transfer material 24 is completed, the transfer residual toner on the intermediate transfer member 20 is cleaned by contacting the intermediate transfer member cleaner 35.

In a color electrophotographic apparatus having an image forming apparatus using the above-mentioned intermediate transfer member, a second image bearing member is attached or adsorbed on a transfer drum, which is a conventional technique, and the first image bearing member is attached thereto. A color electrophotographic apparatus having an image forming apparatus for transferring an image from the body is disclosed in
It is superior to the transfer method as described in JP-A-3-301960 in the following points. That is, there is little color misalignment at the time of superimposing the toner images of each color. Next, as shown in FIG. 1, transferring the image from the intermediate transfer body to the second image carrier without any processing and control (for example, gripping, adsorbing, giving a curvature, etc. to the gripper). Therefore, the second image carrier can be selected in various ways.

For example, selection from thin paper (40 g / m ² paper) to thick paper (200 g / m ² paper) is possible. Transfer is possible regardless of the width and width of the second image carrier. Further, it can handle even envelopes, postcards, label paper, and the like.

Further, since the rigidity of the intermediate transfer member is excellent, dimensional accuracy such as dents, distortions, deformations, and the like is less likely to occur due to repeated use, so that the frequency of replacement of the intermediate transfer member can be reduced.

[0021]

As described above, full-color printers and copiers using an intermediate transfer member have various advantages, but have the following problems.

In recent years, due to the widespread use of color personal computers, high-speed and high-quality color images have been required for printed materials. At the same time, the miniaturization and cost reduction of copiers and printers are progressing rapidly, and full-color copiers and printers using electrophotography, which used to be expensive and mainly used by some corporate users, are now in small and medium offices and general offices. A wider range of usage environments, including even homes, is being targeted. Full-color printers and copiers for such users require ever more compact and low-cost printers, and the need for maintenance work and the resulting reduction in running costs have become even more important. It can be said that there is. However, at present, it is difficult to obtain an intermediate transfer member having the same durability as the life of the main body, and replacement is indispensable. Frequent replacement of the intermediate transfer member is not preferable because it leads to an increase in maintenance work and running costs, and extension of the life of the intermediate transfer member and reduction of the cost are major improvements.

In particular, phenomena relating to the structure itself, such as cracking of the intermediate transfer member, chipping or peeling of a part of the intermediate transfer member, can be said to be the most serious problems that affect the service life. Furthermore,
Deterioration of transferability due to contamination or scraping of the surface of the intermediate transfer member is also an important factor that determines the life of the intermediate transfer member. In order to improve the strength of the intermediate transfer body, there is a method of using an elastic material such as rubber or elastomer for the intermediate transfer body. Can be higher. However, since the smoothness of the surface is lower than that of a hard resin material, problems arise in terms of transfer efficiency, dirt, and the like. Accordingly, a low-cost intermediate transfer member having sufficient durability relating to both the structural strength and the surface releasability of the intermediate transfer member has not yet been obtained. However, the present invention proposes an image forming apparatus using an intermediate transfer member that solves the above-mentioned problem.

An object of the present invention is to reduce the occurrence of problems due to structures such as cracks, partial chipping and peeling of an intermediate transfer member even when used for a long period of time. It is an object of the present invention to provide an image forming apparatus capable of suppressing a decrease in performance due to image formation, and suppressing an increase in maintenance labor and running costs due to replacement of an intermediate transfer member.

[0025]

That is, the present invention is directed to an image forming method in which an image formed on a first image carrier is transferred onto an intermediate transfer member and further transferred onto a second image carrier. In the apparatus, the intermediate transfer member has a surface layer on an elastic layer, and the surface layer is provided with lubricating particles at a ratio of 1 to the total solid content of the entire surface layer.
0 to 80% by weight, the distribution of the lubricating particles in the surface layer is in the range of the following formula, and the surface roughness of the intermediate transfer member is 0.1
An image forming apparatus having a range of about 3 μm.

3.0 ≧ the amount of lubricating particles on the surface layer surface / the amount of lubricating particles inside the surface layer ≧ 0.8

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to satisfy all the characteristics of the present invention, there is a method of providing a surface layer having a sufficient lubricity on the surface of an elastic base layer. Is effective. However, it has been found that even if such a surface layer is used, when a large amount of lubricating particles are added in order to obtain higher surface release properties, the strength and adhesion of the surface layer are reduced. The reason for this is that the amount of the added lubricating particles buried in the binder component and exposed on the surface is smaller than the added amount. In this state, increasing the amount of the lubricating particles until sufficient surface releasability is obtained results in adding an excessive amount of the lubricating particles, resulting in a decrease in strength and adhesion. Therefore, a sufficient amount of lubricating particles are exposed on the surface of the intermediate transfer member to obtain higher surface releasability and good adhesion to the elastic layer, and simultaneously contact the inside of the surface layer and the elastic layer. The problem can be solved by adjusting the distribution and addition amount of the lubricating particles so that the amount of the lubricating particles at the interface does not become excessive. Further, the surface of the intermediate transfer member needs to be smooth in order to reduce the adhesion of toner and to improve the primary transfer efficiency, the secondary transfer efficiency, the cleaning property and the image quality. Therefore, by adjusting the distribution state and surface roughness of the lubricating particles within the range of the present invention, good image quality and high surface releasability,
Surface layer strength and adhesion can be obtained, and the durability of the intermediate transfer member can be improved at relatively low cost.

In the present invention, the JIS average surface roughness is 3 μm.
If it exceeds m, roughness and transferability and cleaning property of the halftone image will be reduced, and if it is less than 0.1 μm, the toner will easily fuse due to contact with a photoconductor or a transfer roller. If the content of the powder particles in the entire surface layer is less than 10% by weight, the releasability is insufficient, and problems such as a decrease in transfer efficiency and an increase in surface fusion are caused. When the content of the lubricating particles in the entire surface layer exceeds 80% by weight, the film strength of the surface layer and the adhesion to the elastic layer are reduced, and the surface cracks or peels off during long-term use, resulting in image defects. . If the above expression is less than 0.8, the effect of the lubricating particles is reduced, and the surface releasability corresponding to the added amount cannot be obtained. If the above expression exceeds 3.0, the flexibility near the surface decreases, and peeling and cracking also occur.

Several methods can be used to adjust various physical properties within the scope of the present invention, but are not particularly limited.

For example, a coating material in which lubricating particles are dispersed is applied on the elastic layer by spraying or dip coating, dried and cured to form a surface layer. Thereafter, a method of polishing the surface to expose the lubricating particles embedded in the binder to the surface and adjusting the surface roughness and the distribution of the lubricant is preferably used.

Further, a method of distributing a large number of lubricating particles near the surface by spraying and repeating the coating by using a coating material in which the amount of lubricating particles is gradually increased during spray coating, and drying and curing the coating. Can also be used. In this case, unlike the case where a primer or the like is used, continuous coating is possible without taking a drying step or the like, and it is possible to form the surface layer of the present invention while minimizing the increase in the number of manufacturing steps.

In the case where the intermediate transfer member is manufactured by centrifugal molding, a surface layer in which a large amount of lubricating particles having a high specific gravity are distributed on the surface by centrifugal force is formed, and then an elastic layer is formed inside the surface layer by centrifugal molding. A method for producing an intermediate transfer member to be formed can be used.

The thickness of the surface layer is preferably about 2 to 100 μm in consideration of maintenance of surface smoothness, securing of strength, and abrasion. More preferably, it is in the range of 5 to 60 μm.

When a liquid lubricant such as silicone oil is added to impart surface lubricity to the intermediate transfer member, a so-called bleeding of the lubricant on the surface of the intermediate transfer member occurs with the lapse of time, and the photosensitive material is exposed to light. It may adhere to the body and cause serious defects such as cracks on the surface of the photoreceptor. In particular, this tendency becomes remarkable when an organic photoreceptor is used. Therefore,
In the present invention, by adding a specific amount of highly lubricating particles, high lubricity is imparted to the surface of the intermediate transfer member, and at the same time, occurrence of lubricant bleed can be prevented, and various characteristics can be satisfied without causing any problem.

As the lubricating particles, fine particles of a resin or the like having a high content of fluorine or silicon are used, and examples thereof include the following.

Various fluorine rubbers, fluorine elastomers,
Fluorocarbon with graphite and graphite bonded to fluorine, ethylene tetrafluoride resin (PTFE), vinylidene fluoride resin (PVDF), ethylene tetrafluoride-ethylene copolymer (ETFE), and ethylene tetrafluoride-perfluoroalkyl Particles of a fluorine compound such as vinyl ether copolymer (PFA), silicone resin particles, silicone powders such as silicone rubber and silicone elastomer, and particles of various resins modified with fluorine or silicone, etc., may be used alone or A plurality of them can be used in combination. In addition, the shape and particle size of the lubricant particles are not particularly limited, but can be used in any shape as long as lubricating properties such as spherical, fibrous and plate-like, and irregular shapes can be obtained, and the particle size is not limited. 0.02 to 50 in consideration of dispersibility and surface properties
The range of μm is desirable. If necessary, these powders may be subjected to a surface treatment within a range that does not impair lubricity. Also, a dispersant can be used within a range that does not cause a problem in various properties.

These high lubricating powders need to be added to the composition constituting at least the surface of the intermediate transfer member. Therefore, when the intermediate transfer member is composed of a plurality of layers, it must be added at least in the surface layer (outermost layer).

Known methods can be used as appropriate for mixing and dispersing such a lubricating powder in at least a binder component such as a resin or an elastomer rubber constituting the surface of the intermediate transfer member. When the binder component is a rubber or an elastomer, a device such as a roll mill, a kneader, and a Banbury mixer is used. When the binder component is a liquid, the material can be dispersed using a ball mill, a bead mill, a homogenizer, a paint shaker, a nanomizer, and the like.

In the present invention, as a method for judging the distribution of the lubricating particles on the surface and inside, the surface layer and the cross section of the surface layer of the intermediate transfer member are measured using an X-ray probe microanalyzer (EPMA), A method for measuring the characteristic X-ray intensity peculiar to the element contained in the element is used. First,
A portion including the surface layer of the intermediate transfer member is cut out with a sharp blade as a measurement sample, and a cross-sectional portion of the surface layer cut by a scanning electron microscope (SEM) equipped with EPMA is enlarged.
Scanning at a width of 2 μm in the thickness direction and 30 μm in the direction parallel to the surface, centering around 5 μm from the elastic layer side in the thickness direction of the surface layer cross section, fluorine (in the case of fluorine atom-containing lubricating particles)
Alternatively, the characteristic X-ray intensity of silicon (in the case of silicon atom-containing lubricating particles) is measured. When the thickness of the surface layer is 10 μm or less, the measurement is performed around 3 μm from the elastic layer side, and when the thickness is smaller, the portion as close to the elastic layer as possible is measured. This is performed at 10 places, and the average of the X-ray intensity per unit area is obtained.
Similarly, the surface layer of the sample cut out is measured at 10 points in the same area from the surface direction and an average is taken. The quantitative ratio is calculated by comparing the characteristic X-ray intensities of fluorine or silicon measured in each part.

In the present invention, the surface roughness is a center line average surface roughness _Ra, which is obtained by using a surf coder SE3400 manufactured by Kosaka Laboratory Co., Ltd. based on JIS B0601.
The average was obtained by measuring three arbitrary points at a cutoff of 0.8 mm, a measurement length of 2.5 mm, and a measurement speed of 0.5 mm / sec.

The intermediate transfer member of the present invention is also suitable when an organic photoreceptor having a protective layer is used. The protective layer is PT
A layer in which FE particles and the like are dispersed is provided outside the charge transport layer (CT layer). The primary transfer characteristic from the photoreceptor to the intermediate transfer member is improved, and good image quality without image defects such as omission during transfer is high. Primary transfer efficiency is obtained. However, if the secondary transfer characteristics of the intermediate transfer body are not sufficient, the transfer residual toner on the intermediate transfer body increases, and the transfer efficiency cannot be substantially improved, and at the same time, image defects such as omission of the secondary transfer occur. . According to the intermediate transfer member of the present invention, such a problem does not occur, and substantial improvement in transfer efficiency and image quality can be achieved by combination with a photoconductor using a protective layer.

The intermediate transfer member used in the present invention has, for example, a roller shape having at least one coating layer on an elastic layer made of rubber, elastomer or resin on a cylindrical conductive support, or FIG. The shape of the belt having the elastic layer as shown in (1) and various aspects can be selected as required for various purposes. 2 to 5 show examples of the configuration.

In each of the figures, reference numeral 100 denotes a rigid cylindrical conductive support, 101 denotes an elastic layer, 102 and 103 denote coating layers, and 104 denotes an intermediate transfer belt.

As the cylindrical conductive support, a metal or alloy such as aluminum, iron, copper and stainless steel, a conductive resin in which carbon and metal particles are dispersed, and the like can be used. Such a cylinder, a cylinder having a shaft penetrating the center of the cylinder, a cylinder having a reinforced interior, and the like can be given.

The rubber, elastomer, and resin used for the elastic layer and the coating layer of the intermediate transfer member used in the present invention include:
For example, elastomers and rubbers include styrene-butadiene rubber, high styrene rubber, butadiene rubber, isoprene rubber, ethylene-propylene copolymer, nitrile butadiene rubber, chloroprene rubber, butyl rubber, silicon rubber, fluorine rubber, nitrile rubber, urethane rubber ,
Acrylic rubber, epichlorohydrin rubber, norbornene rubber and the like can be mentioned. Further, as resins, polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene -Acrylate copolymers (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer and styrene-phenyl acrylate copolymer) Styrene-methacrylic acid ester copolymers (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-phenyl methacrylate copolymer), styrene-α-chloroacrylic acid Methyl copolymer and styrene-acrylonitrile-a Styrene-based resins such as acrylate copolymers (homopolymers or copolymers containing styrene or styrene substituents),
Vinyl chloride resin, styrene-vinyl acetate copolymer, rosin-modified maleic resin, phenol resin, epoxy resin, polyester resin, low molecular weight polyethylene, low molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl Examples include acrylate copolymers, xylene resins, fluororesins, polycarbonates, polyamide resins, polyvinyl butyral resins, and copolymers and mixtures thereof.

The thickness of the elastic layer is 0.5 mm or more,
mm or more, particularly preferably 1 to 10 mm.
Further, the film thickness of the coating layer is preferably a thin layer for further transmitting the flexibility of the lower elastic layer to the upper layer or the surface of the photoreceptor, specifically 3 mm or less, more preferably 2 mm or less, particularly It is preferably from 20 μm to 1 mm.

The volume resistivity of the intermediate transfer member used in the present invention is preferably from 10 ¹ to 10 ¹³ Ω · cm, particularly preferably from 10 ² to 10 ¹⁰ Ω · cm. Further, at least the volume resistivity of the surface layer is preferably within these ranges.

In order to control the resistance as described above, a conductive agent can be added as appropriate within a range not to impair the object of the present invention. For example, various conductive inorganic particles, carbon black, an ionic conductive agent, a conductive resin, a conductive particle-dispersed resin and the like can be mentioned. Specifically, as conductive inorganic particles, particles of titanium oxide, tin oxide, barium sulfate, aluminum oxide, strontium titanate, magnesium oxide, silicon oxide, silicon carbide, silicon nitride, etc. And surface-treated with carbon or the like, and these shapes may be spherical, fibrous, plate-like, irregular, or the like. The ionic conductive agent is an ammonium salt, an alkyl sulfonate, a phosphate ester salt, a perchlorate, or the like. As the conductive resin, a quaternary ammonium salt-containing polymethyl methacrylate,
Polyvinylaniline, polyvinylpyrrole, polydiacetylene, polyethyleneimine and the like can be mentioned. Also,
Conductive particles such as carbon, aluminum and nickel as urethane, polyester,
Examples thereof include those dispersed in a resin such as vinyl acetate-vinyl chloride copolymer and polymethyl methacrylate, but are not necessarily limited thereto, but from the viewpoint of controlling conductivity among these, As the conductive agent of the coating layer, conductive inorganic particles are preferable.

The intermediate transfer member of the present invention is manufactured, for example, as follows.

First, a metal roll as a cylindrical conductive support is prepared. An elastic layer is provided by molding rubber, elastomer, resin, or the like on a metal roll by melt molding, injection molding, dip coating, spray coating, or the like. The means for forming the surface layer is as described above.

[0051]

The present invention will be described in detail below with reference to examples. (Example 1) A roller having an elastic layer with a thickness of 5 mm was prepared by transfer molding a rubber compound having the following composition onto the surface of an aluminum cylindrical cylinder having a diameter of 182 mm, a length of 320 mm and a thickness of 5 mm using a mold. ) Got. All figures are parts by weight

Rubber compounding NBR 100 parts Zinc oxide 2 parts Conductive carbon black 8 parts Paraffin oil 5 parts Vulcanizing agent (sulfur) 2 parts Vulcanization accelerator 3 parts

Next, a paint having the following formulation was prepared.

Paint formulation Polyurethane prepolymer (including solvent) 100 parts Curing agent (including solvent) 50 parts High lubricating powder PTFE particles (particle diameter 0.3 μm) 150 parts Dispersing aid 5 parts Conductive titanium oxide particles (particles) Diameter 0.5μm) 10 parts Toluene 80 parts

A coating layer was formed on the surface of the roller by spraying this coating material, and then the coating was heated at 120 ° C. for 1 hour to remove the residual solvent, and the coating was crosslinked to form a surface layer. A half-circle of a belt-shaped abrasive paper having a width of 50 mm and corresponding to # 800 is wound around this intermediate transfer member for 10
After applying a tension of Kg, the intermediate transfer member is rotated at a speed of 500 rpm, and the belt is moved 5 to 5 times from end to end of the intermediate transfer member.
It moved at a speed of 0 mm / min. At this time, the polishing belt was also fed at a speed of 50 mm / sec by a feeder to remove polishing debris. After this, # 1000
The same surface polishing was performed using an abrasive paper equivalent to No. 1 to obtain an intermediate transfer member exposing the lubricating particles. The proportion of PTFE particles in all the components of the surface layer of the intermediate transfer member is 57%.
%, The thickness of the surface layer is 30 μm, the characteristic X-ray intensity ratio of fluorine by EPMA is 0.98, and the surface roughness (R
_a ) was 0.3.

In order to confirm the durability of the intermediate transfer member, an aluminum cylinder having a diameter of 80 mm and a length of 330 mm is pressed against the intermediate transfer member, and the intermediate transfer member is driven by driving the aluminum cylinder. ,
A load rotation test of 100,000 continuous rotations at a peripheral speed of 120 mm / sec was performed while pressing with a load of 5 kg.

After the load rotation test, the intermediate transfer member was mounted on the full-color electrophotographic apparatus shown in FIG. 1, and the transfer efficiency was changed to monochromatic cyan using an organic photosensitive drum having a protective layer as a photosensitive member. As a result of measurement, the primary transfer efficiency was 96% and the secondary transfer efficiency was 94%, which was sufficiently high, and the image was free of characters, thin lines, and a uniform halftone. After that, 10,000 continuous full-color prints were made, and then the surface of the intermediate transfer member was observed and the image quality of cyan monochromatic was checked. As a result, no particularly problematic defect was observed on the surface of the intermediate transfer member, and the image showed good results as in the initial stage.

Photoreceptor: Organic photosensitive drum having a protective layer in which PTFE particles are dispersed Surface potential: -750 V Color developer (for all four colors): non-magnetic one-component toner Primary transfer voltage: +1.0 KV Secondary transfer voltage: +3 0.0KV Process speed: 120mm / sec Development bias: -550V

The transfer efficiency of the present invention was determined from the following equation.

[0060]

Example 2 An intermediate transfer member was produced in the same manner as in Example 1 except that the ratio of PTFE particles in the surface layer after drying and solidification was changed to 67% by weight.
Using this intermediate transfer member, a load rotation test and a durability test using an actual machine were performed. The image quality and transfer efficiency were as good as in Example 1, and no problematic defects were found on the intermediate transfer member. Table 1 shows the results.

Example 3 An intermediate transfer member was produced in the same manner as in Example 1 except that the ratio of PTFE particles in the surface layer after drying and solidification was changed to 30% by weight.
Using this intermediate transfer member, a load rotation test and a durability test using an actual machine were performed. The image quality and transfer efficiency were as good as in Example 1, and no problematic defects were found on the intermediate transfer member. Table 1 shows the results.

Example 4 In the method for manufacturing an intermediate transfer member of Example 1, the belt-like abrasive paper was changed to a slightly coarse # 500 equivalent, and the second polishing was not performed. R _a of the intermediate transfer body was 2.5 [mu] m. Using this intermediate transfer member, a similar load rotation test and a durability test using an actual machine were performed.
Table 1 shows the results. Although slight unevenness was observed in the halftone image after 10,000 sheets of durability, it was judged that there was no practical problem. Table 1 shows the results.

(Example 5) The coating formulation of Example 1 was spray-coated by adjusting the amount of PTFE particles in the surface layer after drying and solidifying so that the ratio of the PTFE particles in the surface layer became 30% by weight, followed by continuous coating. The coating was adjusted so that the proportion of the PTFE particles was 72% by weight, and the thickness of each coating was adjusted so that the proportion of the PTFE particles in the entire dried and solidified surface layer was 60% by weight. Thereafter, an intermediate transfer member was obtained in the same manner as in Example 1. Using this intermediate transfer member, a similar load rotation test and a durability test using an actual machine were performed. The image quality and transfer efficiency were as good as in Example 1, and no problematic defects were found on the intermediate transfer member. Table 1 shows the results.

(Example 6) The ratio of the lubricating powder in the surface layer after drying and solidification using silicone resin particles having a particle size of 0.5 μm as the lubricating powder of the coating material of Example 1 was 67% by weight. Changed to This paint was applied by spraying, and thereafter an intermediate transfer member was obtained in the same manner as in Example 1. Using this intermediate transfer member, a load rotation test and a durability test using an actual machine were performed.
The image quality and transfer efficiency were as good as in Example 1, and no problematic defects were found on the intermediate transfer member. Table 1 shows the results.

(Example 7) The following compound was formed into a tube by extrusion, vulcanized, polished, and polished to obtain an outer circumference of 400 mm, a width of 240 mm and a thickness of 1 m.
m of a conductive seamless belt was molded.

Rubber compounding NBR 100 parts Zinc oxide 2 parts Conductive carbon black 4 parts Paraffin oil 5 parts Vulcanizing agent (sulfur) 2 parts Vulcanization accelerator 3 parts

The rubber belt was passed through a cylindrical aluminum core, spray-coated while rotating to form the same surface layer as in Example 1, and the surface was polished in the same manner as in Example 1 to form a belt-shaped intermediate layer. A transcript was obtained. This intermediate transfer member is placed on two aluminum cylinders having a diameter of 60 mm and 2 kg
A continuous rotation endurance test of 100,000 rotations at a peripheral speed of 120 mm / sec was performed while applying tension. Thereafter, a print test similar to that of Example 1 was performed using the electrophotographic apparatus of FIG. 4, and good results were obtained as in Example 1. Table 1 shows the results.

(Example 8) Using a centrifugal molding apparatus in which an aluminum cylinder serving as the core of the intermediate transfer member used in Example 1 was set in advance, the surface layer paint of Example 1 was used, and the thickness was 30 μm by centrifugal molding. After curing and forming the surface layer, a 5 mm thick elastic layer of conductive urethane elastomer is formed between the inside of the surface layer and the aluminum cylinder using a two-component curable urethane resin of the following formulation, and the intermediate transfer is performed. The body was made.

Elastic layer composition Two-part liquid urethane A liquid 60 parts Two-part liquid urethane B liquid 40 parts Conductive carbon black 2 parts

Using this intermediate transfer member, a load rotation test and a durability test using an actual machine were performed in the same manner as in Example 1. The image quality and transfer efficiency were as good as in Example 1, and no problematic defects were found on the intermediate transfer member. Table 1 shows the results.

Comparative Example 1 In the intermediate transfer member of Example 1, the proportion of the PTFE resin particles in the surface layer after drying and solidification was changed to 8% by weight. Using this intermediate transfer member, a load rotation test and a durability test using an actual machine were performed in the same manner as in Example 1. Although there was no problem in the load rotation test, the image quality of the actual machine was slightly inferior in halftone uniformity, and the secondary transfer efficiency was 80%, which was considerably lower than that of Example 1. Furthermore,
After 10,000 prints, toner adhesion to the surface of the intermediate transfer member was remarkable, and it was confirmed that there was a problem in both image quality and durability.
Table 1 shows the results.

Comparative Example 2 The ratio of the PTFE resin particles in the surface layer after drying and solidification in the intermediate transfer member of Example 1 was changed to 82% by weight. A load rotation test was performed using this intermediate transfer member in the same manner as in Example 1.
Cracking of the surface layer occurred around 10,000 rotations. Since the effect of the cracks was also observed in the image by the actual machine, it was judged that there was a problem in the durability, and the durability test of 10,000 sheets by the actual machine was not performed.

(Comparative Example 3) In the intermediate transfer member of Example 1, the belt-like abrasive paper was changed to a coarse paper equivalent to # 200 and polished, and the second polishing was not performed. The surface roughness (R _a ) Was 3.3 μm. Using this intermediate transfer member, a load rotation test and a durability test using an actual machine were performed in the same manner as in Example 1. There was no problem in the load rotation test,
The transfer efficiency of the actual machine was slightly inferior, and a problem was observed in the uniformity of the halftone of the image. The uniformity of the image quality after the 10,000-sheet durability test was further deteriorated, and it was judged that there was a problem on the image.

Comparative Example 4 When the surface layer was not polished in the intermediate transfer member of Example 3, the particle distribution ratio was 0.75. Example 1 using this intermediate transfer member
A load rotation test and a durability test using an actual machine were performed in the same manner as described above. Although there was no problem in the load rotation test, the image quality of the actual machine was slightly inferior in halftone uniformity, and the secondary transfer efficiency was slightly lower. Further, although the image quality was not affected after the endurance of 10,000 sheets, adhesion of toner to the surface of the intermediate transfer member was observed. Table 1 shows the results.

[0076]

[Table 1]

[0077]

As described above, in the image forming apparatus, the image formed on the first image carrier is transferred to an intermediate transfer member and further transferred onto a second image carrier. Is composed of at least two layers of an elastic layer and a surface layer, and the JIS average surface roughness of the surface of the intermediate transfer member is 0.1 to
3 μm, the surface layer contains lubricating powder particles, and the content in the entire surface layer is 10 to 80% by weight.
The use of an intermediate transfer body in which the distribution of the lubricating powder particles in the surface layer is within a certain range causes problems related to the structure of the intermediate transfer body, such as cracks and chips, even after long-term durability. Thus, an image forming apparatus having excellent transfer efficiency and image quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a color image output apparatus using a roller-shaped intermediate transfer member.

FIG. 2 is a cross-sectional view of a roller-shaped intermediate transfer having a coating layer on an elastic layer.

FIG. 3 is a cross-sectional view of a roller-shaped intermediate transfer member having a plurality of coating layers on an elastic layer.

FIG. 4 is a schematic diagram of a color image output apparatus using an intermediate transfer belt.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photosensitive drum 2 primary charging device 3 image exposure means 9 paper feed cassette 14 photosensitive drum cleaning device 15 fixing device 20 intermediate transfer member 21 core metal 22 elastic layer 24 transfer material 25 transfer roller 29 bias power supply 35 intermediate transfer member cleaner 41 magenta Color developing device 42 Cyan developing device 43 Yellow developing device 44 Black developing device 61 Bias power supply 100 Core metal 101 Elastic layer 102 Coating layer 103 Coating layer 104 Belt-shaped intermediate transfer body

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Atsushi Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Takashi Kusaba 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor: Akira Shimada, 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor: Hiroyuki Kobayashi, 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (8)

[Claims] 1. An image forming apparatus for transferring an image formed on a first image carrier onto an intermediate transfer member and further transferring the image onto a second image carrier, wherein the intermediate transfer member is formed of an elastic layer. A surface layer containing lubricating particles in an amount of 10 to 80% by weight based on the total solid content of the entire surface layer, and the distribution of the lubricating particles in the surface layer is in the range of the following formula. An image forming apparatus, wherein the surface roughness of the intermediate transfer member is in the range of 0.1 to 3 μm. 3.0 ≧ lubricating particle amount on surface layer surface / lubricating particle amount inside surface layer ≧ 0.8 2. The image forming apparatus according to claim 1, wherein the lubricating particles contain a fluorine atom or a silicon atom. 3. The image forming apparatus according to claim 1, wherein the intermediate transfer member is a roller. 4. The image forming apparatus according to claim 1, wherein the intermediate transfer member is a belt. 5. The image forming apparatus according to claim 1, wherein the first image carrier is a photosensitive drum having a photosensitive layer on a conductive rigid roller, and the intermediate transfer body is a rigid roller having an elastic layer. 6. The image forming apparatus according to claim 1, wherein the first image carrier is a photosensitive drum having a photosensitive layer on a conductive rigid roller, and the intermediate transfer body is a belt. 7. The image forming apparatus according to claim 1, wherein the first image carrier is an organic photoreceptor. 8. The image forming apparatus according to claim 1, wherein the photoconductor is an organic photoconductor having a protective layer on the surface.