JPH10123851A - Intermediate transfer drum covered with seamless tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent image irregularity from occurring by using a seamless tube molded by extruding a semi-conductive thermal plastic resin composition into a tube state by an extrusion machine, bringing it into contact with a tube inner diameter regulation member arranged inside the tube and withdrawing it while the tube state is kept. SOLUTION: An intermediate transfer device is constituted of a photoreceptive drum 1, an intermediate transfer drum 6 and the seamless tube 7 covering the drum 6. An electrophotographic process unit consisting of an electrostatic charger 2, an exposure optical system 3 and a cleaner 5 is arranged around the drum 1. As the tube 7, the tube formed on the drum 6 consisting of a conductive supporting body and the semi-conductive seamless tube covering the outer circumference of the supporting body by such a method that the semi-conductive thermal plastic resin composition is extruded into the tube state by the extrusion machine, brought into contact with the temp.-controlled tube inner diameter regulation member arranged inside the tube and withdrawn while the tube state is kept is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermediate transfer drum used in an electrophotographic or electrostatic recording process in a copying machine, a printer or the like.

[0002]

2. Description of the Related Art FIG. 1 is a side view of an electrophotographic apparatus using an intermediate transfer member. In the figure, 1 is a photosensitive drum, 6 is an intermediate transfer drum, and 7 is a seamless tube coated on the intermediate transfer drum. An electrophotographic process unit including a charger 2, an exposure optical system 3 using a semiconductor laser or the like as a light source, a developing device 4 containing toner, and a cleaner 5 for removing residual toner. Is arranged.

Next, the operation will be described. First, the surface of the photosensitive drum 1 rotating in the direction of the arrow is uniformly charged by the charger 2. Next, an electrostatic latent image corresponding to an image obtained by an image reading device or the like (not shown) is formed on the photosensitive drum 1 by the optical system 3. The electrostatic latent image is developed into a toner image by the developing device 4. The toner image is electrostatically transferred to the seamless tube 7 covered on the intermediate transfer body 6 by the electrostatic transfer device 9 and transferred to the recording paper 11 by the transfer roller 8.

[0004] As such an intermediate transfer member, a belt or a drum in which the resistance of the surface of the intermediate transfer member in the image area and the resistance in the thickness direction are set to the semiconductive area due to the necessity of charging and discharging are disclosed. ing. The following is disclosed as such a drum-shaped intermediate transfer member.

(JP-A-7-152304) An elastic material such as urethane, EPDM, chloroprene or the like, or conductive particles such as carbon, zinc oxide, tin oxide or the like dispersed in an elastic material on a cored metal, is used to form 10 ⁵ to 10 ⁵ . 10 ¹⁰ Ω, preferably 10
A medium resistance elastic layer having a medium resistance of ⁷ to 10 ⁹ Ω is formed, the hardness is 20 ° to 50 °, and the ten-point average roughness is 15 μm.
An example is shown in FIG. However, a method for manufacturing the intermediate transfer drum is not exemplified.

(JP-A-6-301263) A structure in which a resistor layer adjusted to a predetermined resistance value is formed as a dielectric layer on the outer peripheral surface of a conductive drum base made of aluminum, and the resistance layer is made of carbon black. Or, urethane or fluororesin whose resistance value is adjusted by dispersing a metal powder such as aluminum is exemplified. Further, it is described that the resistance value of the resistance layer is preferably 10 ⁶ to 10 ¹² Ω · cm. The method for manufacturing the intermediate transfer drum is not exemplified.

[0007] Japanese Patent Application Laid-Open No. 6-301297 discloses an example in which a conductive rubber substrate made of aluminum has a silicone rubber or urethane rubber layer on the outer peripheral surface and an outer layer of polyvinylidene fluoride is formed on the surface. . Resistance value is 1
It is exemplified that the capacitance is 0 ¹¹ Ω · cm or more and the capacitance is 0.4 μF / m ² or less. The method for manufacturing the intermediate transfer drum is not exemplified.

(1) Although a method for producing such a drum is not disclosed, urethane, EPDM, chloroprene, silicone rubber, ethylene propylene rubber,
Conductive particles such as carbon, zinc oxide and tin oxide are kneaded and dispersed in an elastic material such as synthetic rubber such as nitrile rubber or norbornene rubber, and wound around a drum. It is difficult to uniformly control the resistance value in the semiconductive region by changing the distance between the particles.

Further, the resistance value tends to change depending on the environment, which may cause image unevenness. Further, the rubber surface is rough, and a step for reducing the surface roughness by polishing is required, and it is difficult to perform polishing. As a result, the toner sinks into the fine irregularities on the rubber surface, and the toner adheres and deposits on the rubber surface in the form of a film, which lowers the transfer efficiency of the toner to paper and changes the resistance value, resulting in image unevenness. There is.

(2) In the method of coating a drum with a semiconductive resin by dipping, a coating material in which conductive particles are dissolved sinks in a solution, and the dispersion in the solution is uneven. It is difficult to control. Not good for working environment due to use of solvent. There is also a problem that the solvent volatilizes even after molding, and the resistance value changes due to environmental fluctuations.

(3) The present inventors also attach a seamless belt whose resistance has been adjusted in advance to the outer peripheral surface of the drum,
A configuration as a transfer drum has been proposed. (Japanese Patent Laid-Open No. 6-1
No. 14973)

[0012]

However, as a result of the study by the present inventors, it has been found that, when a certain condition is not satisfied, an image unevenness occurs in a seamless tube covering a drum. (1) When the seamless tube to be coated on the drum is a shrinkable tube, the drum shrinks excessively due to excessive shrinkage, and the shrinkable tube is stretched to form a tube with a controlled resistance value in order to form the tube. Not only is it very difficult, but also a chain of carbon is connected during shrinkage, and the resistance changes drastically, the electrical resistance cannot be controlled, and the image unevenness is affected.

[0013] Further, in the case of bonding to the drum by heat shrinkage when mounting on the drum, the resistance value fluctuates due to the partial shrinkage fluctuation, and the resistance distribution on the entire surface of the drum deteriorates. For this reason, there has been a problem that unevenness occurs in an image due to a transfer failure of toner. Furthermore, the resistance distribution deteriorates probably because the residual stress generated when the shrinkable tube is formed is not uniform over the entire circumference of the tube. for that reason,
There has been a problem that the toner is not transferred by uniform charging, and unevenness occurs in the image due to partial transfer failure of the toner.

Further, the shrinkable tube generally has a poor inner diameter dimensional accuracy, probably because it is manufactured by an outsizing method. For this reason, when covered with the drum, there is a problem in that air is entrapped and the portion does not adhere to the drum, and charges are accumulated in the gap to discharge an image.

(2) Even when the seamless tube coated on the drum is an unshrinkable tube, if the inner diameter accuracy is not uniform within a certain range, air may be entrained or the resistance value may change when the drum is mounted on the drum. There was a problem. Further, since the shrinking force is not as strong as that of the shrink tube, there is a problem that the belt is shifted from the drum due to friction with the blade, various rollers and paper when used for a long time. Therefore, the seamless tube for coating must be adhered to the drum with a conductive adhesive, and there is a problem that the resistance value changes with the curing of the adhesive.

[0016]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an intermediate transfer drum for use in an electrophotographic or electrostatic recording process in a copying machine, a printer, or the like. To provide. Therefore, the present inventors have found that the fluctuation of the resistance value of the drum occurs when the seamless tube is covered and mounted on the drum, and the fluctuation is caused by the non-uniform inner diameter accuracy of one seamless tube. It has unevenness in shrinkage when it is partially mounted on the drum, and as a result, the distance between carbons due to shrinkage does not become uniform uniformly throughout the tube, and the resistance value has a resistance distribution within a certain range in advance. If the roughness of the outer surface is not less than a certain value, the toner will sink into the unevenness and stick to the film, and the transfer efficiency of the toner to the paper will be deteriorated,
In order to create an intermediate transfer drum with a smooth surface and uniform electrical resistance, the outermost seamless tube should be a seamless tube with a low shrinkage rate within an internal diameter accuracy within a certain range, which is molded by an internal regulation method. I found it important. Also, since the outer surface of a seamless tube made by the internal regulation method does not become rough, coating the drum with the seamless tube made by this method provides an intermediate transfer drum with a smooth surface and uniform electric resistance. Can be

As a result of intensive studies in view of the above points, the present inventor has found that a specific intermediate transfer drum has excellent performance which does not cause image unevenness and the like, and has reached the present invention. That is, the gist of the present invention is to provide an intermediate transfer drum comprising a conductive support and a semiconductive seamless tube covering the outer periphery thereof, wherein the seamless tube extrudes the semiconductive thermoplastic resin composition into a tubular shape by an extruder. A seamless tube formed by a method of contacting a temperature-controlled tube inner diameter regulating member disposed inside the tube and taking it out while maintaining the tubular shape, wherein the seamless tube-coated intermediate transfer drum is provided. .

Hereinafter, the present invention will be described specifically. (1) Configuration of Intermediate Transfer Member The intermediate transfer member of the present invention has a configuration in which a non-heat-shrinkable seamless tube whose resistance is controlled and whose inner diameter is controlled is mounted on a conductive support, or a conductive elastic member is provided on the outer periphery of a conductive cylinder. Cover the body,
Further, a configuration in which a non-heat-shrinkable seamless tube with a controlled inner diameter is attached to the outer periphery may be used.

(2) Conductive Support As the conductive cylindrical body, a metal material such as aluminum or sus is generally used because rigidity is required, but is not limited thereto. (3) Conductive elastic body The conductive elastic body is formed of a composition in which conductive powder such as carbon black or metal powder is mixed in silicone rubber, ethylene propylene rubber, nitrile rubber, urethane rubber, or the like. It is not limited. However, since the resistance of these materials varies depending on the environment,
It is necessary to have a low resistance with little change in resistance value.
A preferred resistor has a volume resistance in the thickness direction of 10 ⁸ Ω · c.
m or less, and more preferably 10 ⁶ Ω · cm or less.

(4) Seamless Tube The seamless tube used in the present invention is preferably a seamless tube formed by regulating the inside of the tube. If the accuracy of the inner diameter is not within a certain range, the shrinkage over the entire circumference of the drum during mounting due to thermal shrinkage to the drum will be excessive, so the resistance value of the drum surface will partially differ, and the The electrical resistance of the roller is no longer contained.

As a method for producing a seamless tube having a regulated inside, for example, an internal cooling mandrel method of a downward extrusion method in which the inner diameter of an extruded tube can be controlled with high precision and which is not affected by gravity is used in a continuous melt extrusion molding method. can give. The extrusion device of the internal cooling mandrel type can have the following configuration, for example.

(See Japanese Patent Application Laid-Open No. 4-255332) The upper part of the support pipe is fixed coaxially to an annular die mounted on the extruder, and the mandrel for internal cooling is coaxially fixed to the lower part of this support pipe. I do. Below the mandrel, a plurality of nip rolls for pulling the tube are arranged outside the tube.

Preferably, the annular die is a spiral die. -In the spider die, thickness unevenness is likely to occur at the resin merging portion, and that portion is easily broken. -A spider die cannot be used especially when making a resistance control tube using a carbon dispersed material. This is because the turbulence of the shear rate distribution in the die affects the resistance value of the tube, so that the shear is extremely different at the resin converging portion of the spider mark.

The extrusion direction is desirably vertical. -In the horizontal direction, it sags due to its own weight and impairs roundness. In order to cool in a tube state and to cool to a predetermined diameter, it is desirable to use an internal cooling mandrel system with an accurate inner diameter.・ In the external sizing method, the accuracy of the inner diameter is not high.・ When covering the roller, the inner diameter accuracy of the tube is important. In order to take out the tube without creasing, it is taken out from the outside with a plurality of nip rolls while maintaining a circle. Therefore, it is desirable to adopt a system in which a core is inserted into the support tube rod in an annular die, and the seamless tube is pulled out by a nip roll while contacting the outside of the core. -If the tube diameter is small, the nip roll cannot be inserted inside.・ If the tube diameter is small, it is not possible to nip only the middle part.
Then it bends.・ A core is required to take a thin (thin) seamless tube without creases.

The extruded seamless tube must have necessary conductivity, uniform thickness, inner diameter accuracy and mechanical strength in an unstretched state. This is because, although the mechanical strength can be expected to be improved by the stretching operation, the uniformity of the conductivity is impaired, the durability is impaired because the film is easily torn in the stretching direction, and heating when mounting on the drum is performed. This is because a problem such as a change in the resistance value during contraction occurs.

(5) The resin composition applied in the present invention is a thermoplastic resin, and includes a resin composition containing a conductive filler. As the thermoplastic resin, ethylene (high density, medium density, low density, linear low density), propylene ethylene block or random copolymer, rubber or latex component such as ethylene / propylene copolymer rubber, styrene / butadiene rubber , Styrene-butadiene-styrene block copolymer or hydrogenated derivative thereof, polybutadiene, polyisobutylene, polyamide,
Polyamide imide, polyacetal, polyarylate,
Polycarbonate, polyphenylene ether, modified polyphenylene ether, polyimide, liquid crystalline polyester, polyethylene terephthalate, polysulfone, polyethersulfone, polyphenylene sulfide,
Polybisamide triazole, polybutylene terephthalate, polyetherimide, polyetheretherketone, acryl, polyvinylidene fluoride, polyvinyl fluoride, ethylene tetrafluoroethylene copolymer, polychlorotrifluoroethylene, tetrafluoroethylene hexafluoropropylene copolymer , Tetrafluoroethylene perfluoroalkyl vinyl ether copolymer, polytetrafluoroethylene, fluororubber, alkyl acrylate copolymer, polyester ester copolymer, polyether ester copolymer, polyether amide copolymer, olefin copolymer Polymers, polyurethane copolymers, or a mixture thereof are used.

Preferred resins for coating the intermediate transfer drum are polyvinylidene fluoride, polyvinyl fluoride, ethylene tetrafluoroethylene copolymer, polychlorotrifluoroethylene, tetrafluoroethylene hexafluoropropylene copolymer, and tetrafluoroethylene perfluoro. Alkyl vinyl ether copolymers, fluororesins such as polytetrafluoroethylene and fluororubbers are also preferred to prevent contamination from toner and the like, and polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyester ester copolymers, polyethers An ester-based thermoplastic resin such as an ester copolymer is preferable because the electric resistance value of the electric resistance is small and stable.

As the conductive filler, at least one selected from carbon black, graphite, carbon fiber, metal powder, conductive metal oxide, organic metal oxide, organic metal compound, organic metal salt, conductive polymer and the like is used. Alternatively, a mixture of several kinds of these is preferable. Among them, carbon black is particularly preferred. As carbon black, acetylene black, furnace black,
There is carbon black such as channel black. Acetylene black excellent in dispersibility is preferable so as not to impair the appearance of the film.

The amount of carbon black varies depending on the type of carbon black. In the case of acetylene black, it is preferably 3 to 25 parts by weight based on 100 parts by weight of the thermoplastic resin, and in the case of Ketjen black, it is 1 to 10 parts by weight. Parts by weight are preferred. If it is less than the above range, the conductivity is poor, and if it is more than the above range, the appearance of the product is deteriorated and the material strength is unfavorably reduced. The resin composition may contain various additional components to be added to a usual resin composition as long as the object of the present invention is not impaired. Such components include antioxidants, lubricants, release agents, and the like.

As long as the effects of the invention are not significantly impaired,
The following additional components other than the above may be further added.
As thermoplastic resin, thermosetting resin, various fillers,
For example, calcium carbonate, talc, mica, silica, alumina, aluminum hydroxide, magnesium hydroxide, barium sulfate, zinc oxide, zeolite, wollastonite, diatomaceous earth, glass beads, bentonite, montmorillonite, asbestos, hollow glass spheres, Fillers such as graphite, molybdenum disulfide, titanium oxide, aluminum fiber, stainless steel fiber, brass fiber, aluminum powder, wood powder, rice hull, graphite, metal powder, conductive metal oxides, organometallic compounds, and organic metal salts I can give it. Examples of the additives include antioxidants (phenol-based, sulfur-based, and the like), lubricants, various organic and inorganic pigments, ultraviolet absorbers, antistatic agents, dispersants, neutralizing agents, foaming agents, and plasticizers. , A copper damage inhibitor, a crosslinking agent, and a flowability improver.

(6) Conductivity of Seamless Tube As a seamless tube for coating the transfer drum, the surface resistivity is 1 × 10 ³ to 10 ¹⁵ Ω / □, and the volume resistivity is 1 × 10 ³ to 10 ¹⁵ Ω ·. cm. Desirable surface resistance and volume resistance are 10 ⁶ to 10 ¹³ Ω / □, Ω ·
cm. If the conductivity is too high (the resistance is too low), conduction from the belt material to the conductive support may occur due to the application of voltage, and the chargeability of the belt coated on the conductive support may decrease, resulting in a seamless toner. The transfer efficiency from the tube to the paper decreases. If the conductivity is too low (the resistance is too high), it is difficult to remove the charge when transferring the toner from the intermediate transfer drum to the recording paper, and the transfer efficiency of the toner to the paper deteriorates.

(7) Variation in the conductivity of the seamless tube The range of variation in the conductivity of the seamless tube must be such that the maximum value is within 100 times the minimum value. When the seamless tube is heated and shrunk to the drum and attached, the resistance value slightly fluctuates. Therefore, it is preferably within 10 times, and more preferably within 5 times. If it exceeds 100 times, the image becomes uneven and cannot be used.

(8) Accuracy of Inner Diameter of Seamless Tube The variation in the inner diameter of the seamless tube is preferably within ± 0.5% of the average inner diameter of the tube. 0.
When it exceeds 5%, when the seamless tube is mounted on the drum by heat shrinkage, air is entrained or wrinkles are generated at a large inner diameter, and uniform charging is not performed. In addition, the fluctuation of the resistance value when contracted becomes large, and the ratio between the maximum value and the minimum value of the electric resistance value becomes 100%.
In some cases, the value exceeds twice. A more preferable inner diameter accuracy is within ± 0.3%. More preferable inner diameter accuracy is ±
It is within 0.1%.

(9) Outer Surface Roughness of the Seamless Tube The roughness of the seamless tube is preferably within 3 μm as a ten-point average roughness. The average particle size of the toner is generally 5μ.
When the particle size exceeds 3 μm, the toner having a small particle size sinks into minute irregularities and the toner adheres and deposits on the surface in the form of a film, thereby deteriorating the transfer efficiency to paper. The resistance value may change, resulting in image unevenness. More preferably, the roughness of the seamless tube is 1 μm or less as a ten-point average roughness.

(10) Heat Shrinkage of Seamless Tube The heat shrinkage of the seamless tube is preferably 10% or less. If it exceeds 10%, the electric resistance tends to fluctuate.
It should be noted that as long as the heat shrinkage is 10% or less, it does not matter whether the seamless tube is stretched. Preferred thermal shrinkage is 5%
It is as follows.

(11) Thickness of the seamless tube The thickness of the seamless tube is from 25 μm to 1000 μm.
m or less, more preferably 50 μm or more and 200 μm or less. When the thickness is less than 25 μm, the seamless tube is undesirably wrinkled when attached to the conductive support. On the other hand, if the thickness exceeds 1000 μm, the seamless tube becomes hard, does not deform elastically, becomes less flexible, and damages the photosensitive member, which is not preferable.

(12) Method for Attaching Seamless Tube to Drum As a method for attaching the seamless tube of the present invention to the drum, a known method such as bonding by heat shrinking or bonding via an adhesive may be used. Can be. Since the seamless tube of the present invention has an inner diameter accuracy of ± 0.5% and is not stretched basically, it contracts and adheres uniformly to the drum due to heat shrinkage, and there is almost no air entrainment or fluctuation in resistance value.

(13) Reinforcement tape Further, since the blade, paper, and photoreceptor come into contact with the shoe side of the drum coated with the seamless tube, the seamless tube is coated for the purpose of preventing the tube from being displaced from the drum due to the friction. It is preferable that the tube and the drum be bonded to the image-receiving area of the transfer drum with a reinforcing tape, and the tube and the drum have a structure in which the bonding is strengthened. A preferred reinforcing tape is a tape obtained by applying a single-sided adhesive to a biaxially stretched polyester tape, but is not limited thereto.

(14) Width of Seamless Tube The width of the seamless tube is larger than the width of the support, and it is preferable to arrange the tube so that the end surface of the drum is covered with the tube for the purpose of preventing the tube from shifting from the drum due to friction. The preferred tube width is 1 mm from the drum width
The length is more preferably 5 mm or more. Further, a length of 30 mm or more is not preferable because the space becomes too large in the design of the machine, but the performance is not impaired in preventing the tube from being displaced.

(15) Adhesive Further, the tube and the drum may be adhered to the image-receiving regions at both ends of the transfer drum covered with the seamless tube with an adhesive. In the image area, the conductivity of the adhesive changes depending on the environment, and the electric resistance of the drum changes depending on the environment. A preferable adhesive is an acrylic or silicone rubber based conductive adhesive such as carbon or metal powder.

(16) Drum Further, since a blade, paper, or a photosensitive member comes into contact with the shoe side of the drum coated with the seamless tube, the drum coated with the seamless tube for the purpose of preventing the tube from being displaced from the drum due to the friction. A transfer drum formed by roughening the surface to 10 μm or less, covering with a tube, and shrinking the tube is preferable in terms of cost. 1 drum surface
If it exceeds 0 μm, the surface roughness of the drum after installing the seamless tube exceeds 3 μm, which is not preferable.

[0042]

EXAMPLE As shown in Table 1, each component was supplied to an extruder at a predetermined ratio, kneaded, and a pellet was formed into a molded product by the following method, and evaluated by the following method. Table 1 shows the results. Materials used in Examples and Comparative Examples are as follows. 1. Ethylene tetrafluoroethylene copolymer (trade name “AFLON COP C55AP 2. Polybutylene terephthalate (trade name“ Novadol 502 ”manufactured by Mitsubishi Engineering-Plastics Corporation) manufactured by Asahi Glass Co., Ltd.)
0 "3. Polycarbonate (Mitsubishi Engineering Plastics Co., Ltd., trade name "Iupilon E2000") 4. Polyetherester copolymer (Toyobo Co., Ltd. trade name "Perprene P150B" 5. Acetylene black (Denka Black, trade name "DENKA BLACK"")

Experiments and evaluation methods in Examples and Comparative Examples are as follows. 1. Surface specific resistance (Ω / □) Using a surface resistance meter Hiresta HA probe (manufactured by Yuka Denshi Co., Ltd.), measurement was performed at a measuring voltage of 500 V and a measuring time of 10 seconds at a pitch of 20 mm in the circumferential direction of the tube. 2. Inner diameter accuracy Cut a seamless tube with a three-dimensional dimension measuring instrument, measure the circumferential dimensions of both ends and the center of the tube, and if it is within ± 0.5% of the average inner diameter, ○, exceed 0.5% The case was evaluated as x. 3. Outer surface roughness Surface roughness profile measuring machine “Surfcom 5” manufactured by Tokyo Seimitsu Co., Ltd.
70A ", the ten-point average roughness of the outer surface of the tube was measured. 4. Heat shrinkage After heating at 100 ° C. for 1 hour, the shrinkage when left at room temperature was determined. Hereinafter, the present invention will be further described with reference to specific examples.

Examples 1 to 6 Materials having the composition shown in Table 1 are kneaded with an extruder of 30φ. The kneaded pellets are extruded below the annular die in the form of a molten tube using an extruder with a circular die of 40φ. The extruded molten tube was mounted via a support rod on the same axis as the annular die,
It was brought into contact with the outer surface of a cooling mandrel of φ180 to be cooled and solidified to obtain a seamless tube. Next, the seamless tube was taken out while maintaining the cylindrical shape by the core installed in the seamless tube and the roll installed outside. The obtained tube was heated and shrunk to an aluminum drum having a diameter of 180 mm and bonded to form an intermediate transfer drum. When the obtained intermediate transfer drum was set in the apparatus shown in FIG. 1 and the image was evaluated, no image unevenness occurred.

Comparative Example 1 An intermediate transfer drum was obtained in the same manner as in Examples 1 to 5, except that the extruded molten tube was cooled and solidified by an outsizing device to obtain a seamless tube. The obtained intermediate transfer drum was set in the apparatus shown in FIG. 1 and the image was evaluated. As a result, image unevenness occurred.

Comparative Example 2 An intermediate transfer drum was obtained in the same manner as in Examples 1 to 5, except that the molten parison was pressed against a mold disposed outside using a blow molding apparatus to obtain a cooled seamless tube. . FIG. 1 shows the obtained intermediate transfer drum.
When the image was evaluated by installing it in the above-mentioned apparatus, image unevenness occurred.

Comparative Example 3 An intermediate transfer drum was obtained in the same manner as in Examples 1 to 5, except that the extruded molten tube was obtained by a shrink tube forming method using an outsizing apparatus and a stretching apparatus in a seamless shrink tube forming method. . The obtained intermediate transfer drum was set in the apparatus shown in FIG. 1 and the image was evaluated. As a result, image unevenness occurred.

[0048]

[Table 1]

[0049]

When the intermediate transfer drum according to the present invention is used in an intermediate transfer device of an electrophotographic or electrostatic recording process in a copying machine, a printer or the like, no image unevenness or the like occurs.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of an electrophotographic copying machine incorporating an intermediate transfer drum of the present invention.

FIG. 2 is a diagram of an intermediate transfer drum in which a conductive support is covered with a seamless tube.

FIG. 3 is a diagram of a seamless tube-coated intermediate transfer drum in which a seamless tube is reinforced by an end face reinforcing tape.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photosensitive drum 2 charging device 3 exposure optical system 4 developing device 5 cleaner 6 intermediate transfer drum 7 seamless tube 8 transfer roller 9 electrostatic transfer device 10 reinforcing tape 11 recording paper

Claims (12)

[Claims] 1. An intermediate transfer drum comprising a conductive support and a semiconductive seamless tube covering the outer periphery thereof, wherein the seamless tube extrudes a semiconductive thermoplastic resin composition into a tube shape by an extruder, and the inside of the tube is extruded. A seamless tube formed by a method in which the tube is brought into contact with a temperature-regulated tube inner diameter regulating member disposed in the above and further withdrawn while maintaining the tubular shape. 2. An intermediate transfer drum comprising a conductive support and a semiconductive seamless tube covering the outer periphery thereof, wherein the seamless tube has a surface electric resistance of 10 ³ or more.
An intermediate transfer drum coated with a seamless tube, wherein the maximum value and the minimum value are within 10 times at 10 ¹⁵ Ω / □. 3. An intermediate transfer drum comprising a conductive support, a conductive elastic body covering the outer periphery thereof, and a semiconductive seamless tube further covering the outer periphery thereof, wherein the seamless tube has a surface electric resistance of 10 ³ to 10 ³ . 10 ¹⁵ Ω /
The seamless tube-coated intermediate transfer drum characterized in that the maximum value and the minimum value are within 100 times. 4. The seamless tube-coated intermediate transfer drum according to claim 1, wherein the inner diameter of the seamless tube is within ± 0.5% of the average inner diameter over the entire width of the tube. 5. The seamless tube-coated intermediate transfer drum according to claim 1, wherein the outer surface of the seamless tube has a ten-point average roughness of 3 μm or less. 6. The heat shrinkage of the seamless tube is 10%.
4. The seamless tube-coated intermediate transfer drum according to claim 1, wherein: 7. The seamless tube-coated intermediate transfer drum according to claim 1, wherein the thickness of the seamless tube is 25 μm or more and 1000 μm or less. 8. The seamless tube-coated intermediate transfer drum according to claim 1, wherein the seamless tube is attached by heat shrinkage or bonded via an adhesive. 9. The seamless tube-coated intermediate transfer member according to claim 1, wherein the seamless tube and the conductive support are adhered to the image receiving area of the intermediate transfer drum coated with the seamless tube with a reinforcing tape. drum. 10. The seamless tube-coated intermediate transfer member according to claim 1, wherein the seamless tube and the conductive support are adhered to the image-receiving region of the intermediate transfer drum coated with the seamless tube with an adhesive. drum. 11. The seamless tube-coated intermediate transfer drum according to claim 1, wherein the width of the seamless tube is larger than the width of the support, and the both ends of the conductive support are covered with the tube. 12. The seamless tube-coated intermediate transfer drum according to claim 1, wherein the outer surface of the conductive support covering the seamless tube is roughened to 10 μm or less, and then the seamless tube is covered.