JP3411091B2 - Polyimide composite tubing - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a copying machine, a facsimile,
Polyimide composite tubular material useful for electrophotographic device belts, etc., in which transfer of visible image (toner image) and fixing to copy paper, or formation of visible image to fixing in the same process in image forming apparatus such as word processor Regarding

[0002]

2. Description of the Related Art Generally, in an image forming process by an electrophotographic apparatus, an insulating photoconductor is used as a photoconductor, an electrostatic latent image corresponding to an original is formed on the surface by corona charging and light irradiation, and this is used as a toner. A visible image is formed with a developer such as. This toner image is transferred to the upper surface of a copy material such as copy paper or overhead project (OHP) film by an electric method such as corona discharge. After that, a series of processes are completed by heat-fixing on the copy material using a means such as heating.

As described above, the processes from image formation to fixing in the electrophotographic apparatus are performed in the order of the electrostatic latent image process on the surface of the photosensitive member, the image transfer process on the copying material, and finally the heat fixing process. It can be roughly divided into three processes, and each is functioning. Among these processes, the heat fixing process using the polyimide tubular article related to the present invention is as follows.

A seamless tubular material made of a polymer material, for example, a heat-resistant material such as polyimide resin or polyparabansan is used as a heat fixing belt for a copying machine, a laser beam printer, a facsimile, or a heat-resistant endless belt for a heat transfer printer. It is used. Here, a polyimide tubular material used as a heat fixing member of a copying machine or a laser beam printer will be described.

In a copying machine or a laser beam printer utilizing electrophotography, a heat roller device is generally used as a fixing device for fixing a toner image formed on a copying machine or transfer paper.

That is, the copy paper on which the toner image is formed is sequentially fed between the fixing roller having a heating mechanism and the pressure roller pressed against the fixing roller to heat and melt the toner, thereby thermally fixing the toner image. It is what makes me.

In recent years, the technical development of this fixing device has progressed, and a polyimide tubular material is used instead of the heat fixing roller. The feature of this fixing device is that the heat fixing is performed on the surface of the thin film polyimide tubular object through the heater,
Unlike the heat fixing roller, there is no need to preheat the fixing roller in advance, and the heat fixing can be started immediately when the power switch is turned on, and at the same time, the heater has a small capacity and consumes less power. Further, it is considered useful for increasing the speed of the laser beam printer.

Recently, there has been proposed an electrophotographic system in which a toner image transfer belt and a fixing belt of an image forming apparatus are also used (JP-A-4-335681). According to this method, the toner image on the photosensitive drum is
It is transferred onto a metal belt coated with a fluororesin, and then the transferred toner image is fixed on paper.

[0009]

However, in the transfer of a toner image by a metal belt coated with a fluororesin proposed in the above-mentioned Japanese Patent Laid-Open Publication No. 4-335681, the base material is a metal belt, so that charging is not performed. There is a problem in that it is difficult to control and a practical electronic photograph cannot be obtained.

In addition, at present, no method has been put into practical use in which the method of processing from the formation of a visible image to the heat fixing in the same process is integrated. Generally, a characteristic that is required for a belt that forms and transfers a visible image and fixing on a copy paper (transfer material) in the same process is that an electrostatic recording medium causes electrostatic charge such as corona discharge when a visible image is formed. It is necessary that the electrostatic charge applied to the surface of the recording material by the applying means is stably retained on the surface of the recording material until it is visualized by development.
Further, it is necessary to have sufficient surface potential and electric charge to obtain a clear visible image with high density.

Further, in order to perform image formation efficiently, it is desirable that the rise of charging be fast. Next, at the time of fixing on copy paper, a highly releasable surface such as a fluororesin layer is necessary to prevent offset of a visible image. However,
When a polyimide resin film is used as a base layer and a fluororesin layer with high releasability is provided on the surface and used as an electrostatic recording layer, the dielectric constant of the fluororesin layer is low and the electrostatic capacity of the recording body is small However, there is a problem that the charge and the potential of the recording material are significantly attenuated even when the rise and the charging potential are good, and therefore when a visible image is formed, a high density is not obtained and a clear image cannot be obtained. Further, it is easily conceivable that the capacitance of the recording material can be increased by reducing the film thickness of the fluororesin layer in the above configuration, and the above-mentioned drawbacks can be improved. The insulation of the fluororesin layer is not secured, a high charging potential is not obtained, and therefore, a high-density visible image cannot be obtained, and the film thickness is thin, so that the strength of the recording material is weakened. was there.

Further, even if the metal layer and the fluororesin layer are simply provided on the conventionally used polyimide seamless film, there is a problem that the adhesion between the metal layer and the fluororesin layer is weak. In the case of the above, there is a problem that the strength of the film is weak and the film is easily scratched.

Generally, as a method for increasing the adhesion between the fluororesin layer and the substrate, various fillers such as glass fiber, glass beads, carbon fiber and molybdenum disulfide are mixed in the fluororesin, or the fluororesin and the binder resin (epoxy) are used. Enamel-based resins such as tough coat enamel, which is a mixed resin with a base resin or imide-based resin), are known, but these methods are possible when the film thickness is large, but in a thin film having a film thickness of 1 μm or less. When the filler is mixed, the film strength becomes weak and becomes brittle. Further, there is a problem that it is difficult to form a thin film with an enamel system.

In order to solve the above-mentioned conventional problems, the present invention uses a polyimide seamless film having excellent heat resistance and strength characteristics as a base material, provides a metal layer on the base material, and has high adhesion with the metal layer. By providing a highly insulating fluororesin layer on the surface, the surface has a large amount of charge, and in the formation and transfer of a visible image, a high density is formed to form a clear visible image.
An object of the present invention is to provide a polyimide composite tubular article which is useful for a belt which is satisfactorily fixed without being offset in fixing on copy paper.

[0015]

In order to achieve the above-mentioned object, the polyimide composite tubular article of the present invention has a conductive thin film layer of 10 ³ Ω / □ or less provided on the surface of a tubular polyimide seamless base film. In this structure, an inorganic coating layer and a fluororesin layer are provided in this order on the functional thin film layer.

In the above structure, the metal thin film layer is preferably at least one layer selected from a vapor deposition layer, a plating layer, a sputtering layer and a coating layer.
Further, in the above-mentioned constitution, it is preferable that the inorganic coating layer is a thin film obtained by gelling the sol of the inorganic oxide.

In the above structure, the inorganic oxide is S
It is preferably at least one layer selected from iO ₂ , TiO ₂ , ZrO ₂ , and Al ₂ O ₃ . Further, in the above structure, it is preferable that the fluororesin layer contains BaTiO ₃ which is a high dielectric constant material and carbon powder which is a conductive material.

In the above construction, the thickness of the polyimide seamless base film is preferably in the range of 10 to 500 μm. Further, in the above-mentioned constitution, it is preferable that the polyimide composite tubular article is a belt capable of performing formation and transfer of a visible image of the image forming apparatus and fixing to a copy paper in the same process.

[0019]

According to the above-mentioned structure of the present invention, the metal thin film layer is provided on the surface of the tubular polyimide seamless base film, and the inorganic coating layer and the fluororesin layer are provided in this order on the metal thin film layer. It is possible to realize a polyimide composite tubular article having high adhesion between the metal layer and the fluororesin layer, high insulation, a large amount of surface charge, good toner retention, and high image quality.

In the above structure, it is preferable that the metal thin film layer is at least one layer selected from a vapor deposition layer, a plating layer and a sputtering layer or a coating layer, because a uniform metal thin film layer can be obtained.

Further, in the above-mentioned constitution, when the inorganic coating layer is a thin film obtained by gelling the sol of the inorganic oxide, these fine particles have a high surface area of 10 to 1000 m ² / g, and the fine particles between the fine particles and the fluororesin are Anchoring effect (anchor effect) occurs, and the adhesion and strength of the fluororesin with the base material are improved, and the insulating property is secured, which is preferable.

Further, in the above structure, at least one sol selected from SiO ₂ , TiO ₂ , ZrO ₂ , and Al ₂ O ₃ can be gelled and used as the inorganic oxide.

Further, in the above structure, it is preferable that the fluororesin layer contains BaTiO ₃ which is a high dielectric constant material and carbon powder which is a conductive material because the transfer of the toner image becomes good.

In the above structure, it is preferable in terms of strength that the thickness of the polyimide seamless base film is in the range of 10 to 500 μm. Further, in the above configuration, it is preferable to use the polyimide composite tubular material for the transfer belt and / or the fixing belt of the toner image of the image forming apparatus because the apparatus can be downsized and the power consumption can be reduced.

[0025]

EXAMPLES The present invention will be described in more detail with reference to the following examples. The endless belt of the present invention is shown in FIG.
As shown in the cross-sectional views of (a) and (b), a metal layer 2 such as aluminum which is a conductive layer is provided on the outer side of a polyimide base film layer 1 which is a heat resistant layer, and an inorganic coating layer 3 is further provided thereon. A fluororesin layer 4 as a release layer / insulating layer is provided thereon. 1 (a) is a sectional view in the length direction of the present tube, and FIG. 1 (b) is a sectional view in the circumferential direction. The diameter, thickness (thickness of the base material or thickness of the heat conductive layer), length, etc. of the tubular article of this embodiment can be arbitrarily set according to the application, but a heat fixing belt for a copying machine or the like. In the use of, for example, the diameter 20-100m
m, the thickness is 20 to 100 μm, and the length is preferably about 200 to 400 mm.

The seamless tubular product made of a polyimide resin can be obtained by various methods such as extrusion and casting. In the composite tubular article of this example, a tubular article made of a polyimide resin as a base can be obtained by the following method. That is, as shown in FIG. 2, a precursor solution 14 of polyimide resin and the like are prepared in a container 15. Next, a cylindrical inner mold 10 having substantially the same inner diameter as the required tubular material is prepared in advance, the polyimide precursor solution 14 is applied to the outer surface of the inner mold 10, and then the coating solution is applied. A ring-shaped die (outer mold) 16 having a constant gap (the clearance determines the thickness of the tubular product) with respect to the outer diameter of the mold in order to uniformly mold the surface of the mold 16 Is dropped by itself only by the weight of the die, and the polyimide precursor solution is applied to the outer surface of the inner die with a uniform thickness. Reference numeral 13 is a polyimide precursor solution thin film applied to a uniform thickness.

Next, the polyimide precursor solution thin film cast on the surface of the inner mold 10 is placed in a heating constant temperature bath, and the imidization reaction is allowed to proceed at a predetermined temperature to form a film-like seamless tubular product. At that stage, the mold is released from the mold to obtain a seamless tubular product of polyimide resin. Figure 3
[Fig. 3] is a cross-sectional view (a) in the length direction of the obtained polyimide tubular article 17 and a cross-sectional view (b) in the direction perpendicular to the length direction. As the inner mold 10, for example, it is preferable to coat the surface of a stainless steel metal pipe with a glass coating liquid and bake it to form a glass coating layer in order to improve the releasability of the polyimide tubular product.

The polyimide precursor is obtained, for example, by reacting an aromatic tetracarboxylic dianhydride with an aromatic diamine component in an organic polar solvent.
The tetracarboxylic acid component is not particularly limited and includes, for example, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, and 3 , 4 ', 3,4'-benzophenone tetracarboxylic dianhydride, pyromellitic dianhydride, etc., and salts or ester derivatives of these tetracarboxylic acids, or a mixture of two or more thereof. The diamine component is not particularly limited, and includes, for example, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether and 3,3'-dimethoxy-
Diphenyl ether-based diamines such as 4,4'-diaminodiphenyl ether and 3,3'-dimethyl-4,4'-diaminodiphenyl ether, diphenithioethers such as 3,3'-diphenylthioether and 4,4'-diaminodiphenylthioether Diamine, 4,4 '
-Benzophenone-based diamines such as diaminobenzophenone, other 3,3'-diaminodiphenylmethane,
Examples thereof include diphenylmethane-based diamines such as 4,4′-diaminodiphenylmethane, paraphenylenediamine, and metaphenylenediamine.

Examples of the organic polar solvent include N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, phenol, o-cresol, m-cresol, p-cresol, dimethyl oxide and the like. It is not limited.

The viscosity of solutions of these coating materials is usually 50.
It is preferably about 10,000 to 10,000 poises, particularly about 500 to 5,000 poises. Next, various methods such as a coating method, a plating method, a vapor deposition method, a sputtering method, an ionized molecule deposition method, and a lamination method can be used as a method for depositing and laminating the outer surface metal layer of the polyimide tubular material.

Next, the inorganic coating layer 3 is formed of a sol of inorganic oxides such as SiO ₂ , TiO ₂ , ZrO ₂ , and A.
A thin film obtained by gelling at least one sol selected from l ₂ O ₃ is used. In the inorganic sol solution, submicron-sized ultrafine particles are uniformly dispersed in the liquid,
It can be applied like a paint to a fixed surface to give a gelled gelled film of sol to the surface. Also, these fine particles have a high specific surface area of 10 to 1000 m ² / g, and the anchor effect with the fluororesin (anchor effect).
Occurs, the adhesion and strength of the fluororesin to the base material are improved, and the insulation is secured. Further, from this, it is possible to form the fluororesin layer in a thin film, so that the amount of charges charged on the surface is large, and the toner holding property and the image can be improved.

Next, the fluororesin layer 4 is formed of, for example, polytetrafluoroethylene resin (PTFE), tetrafluoroethylene-perfluorovinyl ether copolymer (PT).
Fluorine resins such as A) and tetrafluoroethylene-hexafluoropropylene copolymer (FEP) can be used. These fluororesins can be formed, for example, by applying an aqueous solution dispersion by dipping, drying and baking.

Furthermore, the dielectric constant can be improved by mixing and preparing the fluororesin layer with BaTiO ₃ which is a high dielectric constant material and carbon powder such as carbon black which is a conductive material.

Next, FIGS. 4 and 5 are cross-sectional views of an electrophotographic apparatus which is an example of the application of the composite tubular article of the present invention. FIG. 4 shows an electrophotographic apparatus in which formation of a visible image and fixing on a copy paper are performed in the same process. In FIG. 4, 51 is a copy paper, 50 is a paper feed roller for feeding the paper, and 4 is a paper feed roller.
Reference numeral 9 is a pressure roller, 46 is a heater, 41 is a composite tubular material of the present invention, 42 is a recording head, 43 is a developing device, 44 is a cleaning device, 45 is a static eliminator, and 47 is a composite tubular material. Is a driving roller, 48 is a tension roller, 52 is a visualized toner image, and 53 is a heat-fixed image after heat-fixing.

In the above, the electrostatic latent image formed by the recording head 42 becomes the toner image 52 visualized by the developing device 43. On the other hand, the copy paper 51 sent out from the paper supply roller 50 is narrowed in pressure between the pressure roller 49 and the heater 46 in the fixing section, and the toner image 52 on the composite tubular material 41 is heated and pressed and fixed. It On the other hand, the toner image remaining on the composite tubular material 41 is neutralized by the static eliminator 45 and then cleaned by the cleaning device 44. The composite tubular article 41 is set so that the polyimide base film is on the inside and the fluororesin layer is on the outside. The electrophotographic apparatus of the above method can reduce the transport distance as compared with the conventional method, the number of required parts is small, a clear image can be obtained, and the apparatus cost is low.

Further, FIG. 5 shows an electrophotographic apparatus in which a visible image is transferred and fixed on a copy paper in the same process. In FIG. 5, 21 is a copy paper, 22 is a paper feed roller for sending out the copy paper, 23 is a backup roller, 24 is a heating element holder, 24 'is a heating element, 25 is a composite tubular article of the present invention, and 26 is a discharge roller. , 27 and 34 are static eliminators, 2
8, 32 is a cleaning device, 29 is a photosensitive drum, 30
Is a developing device, 31 is a driving roller for driving the composite tubular material, and 33 is a transfer roll. In the above, the electrostatic latent image on the photosensitive drum 29 is visualized by the developing device 30 and becomes a toner image. Then, it is transferred to the composite tubular material 25 at the position of the transfer roll 33. On the other hand, the copy paper 21 sent out from the paper supply roller 22 is narrowed in pressure between the backup roller 23 and the heating element holder 24 in the fixing section, and the toner image transferred to the composite tubular material 25 is heated and fixed. . After that, the copy paper 21 is discharged from the discharge roller. On the other hand, the toner image remaining on the photosensitive drum 29 is neutralized by the static eliminator 27 and then cleaned by the cleaning device 28. The toner image remaining on the composite tubular material 25 is neutralized by the static eliminator 34 and then cleaned by the cleaning device 32. The composite tubular article 25 is set so that the polyimide base film is on the inside and the fluororesin layer is on the outside. The electrophotographic apparatus of the above method requires a small number of parts, can obtain a clear image, and has a low apparatus cost.

(Example 1) (1) Preparation of polyimide base film layer Stainless steel metal pipe with outer diameter of 45 mm and length of 30 mm
The surface of the glass is coated with glass coating liquid and baked
And an inner mold was prepared. Then as a polyimide precursor
The viscosity of 1000 poise is 3,3 ', 4,4'-bife.
Nyltetracarboxylic dianhydride and paraphenylenediami
The polyimide precursor obtained by reacting
-2 Polyimide precursor obtained by dissolving in pyrrolidone
A solution was prepared. Contains this polyimide precursor solution
As shown in Fig. 2, immerse the inner mold in the container
Pull up, and then remove the polyimide precursor solution on top of the mold.
A ring-shaped die with an inner diameter of 45.4 mm is mounted on the upper part.
Place it on the inner surface of the inner mold and let it travel by dropping only by its own weight.
Liquid-form a 0.1 mm thick polyimide precursor solution with uniform thickness
Typed Then coated with this polyimide precursor solution
Move the mold to a temperature of 120 ° C for 40 minutes and a temperature of 200 ° C for 2 minutes.
Heat for 0 minutes, then at a temperature of 250 ° C. for 60 minutes, and 3
Heat at 80 ℃ for 40 minutes to imidize and
A seamless tubular product made of resin was obtained. This poly im
The film thickness of the tube was 20 μm. (2) Formation of metal layer Aluminum is vapor-deposited on the outer layer of the polyimide tube.
Method (ion beam sputtering (IBS), conditions:
Fast voltage 1500V, deceleration voltage -1500V, arc voltage
70V, target current 50mA, film forming temperature, room temperature
The film was formed to a film thickness of 0.05 μm by the film formation time of 5 min.
In addition to the vapor deposition method, this method includes electroless plating and vacuum evaporation.
A method such as dressing may be used, and 10³With a conductive layer of Ω / □ or less
I wish I had it. Conductivity of the conductive layer is aluminum, copper, etc.
As described above, a highly conductive one is preferable. (3) Formation of inorganic coating layer Next, silica sol (Si
O₂) (Solid content 30-31 wt%, dispersion medium isopropyl
Alcohol (IPA), particle size 10-20 nm, viscosity 3
(~ 10CP) and apply by dip coating
Cloth, dry at 100 ℃ for 10 minutes, and 150 ℃ for 30 minutes
It was At this time, adjust the thickness of the gel film to 0.1-0.2 μm.
Arranged SiO as the inorganic sol₂Ti other than sol
O₂, ZrO ₂, Al₂O₃Other sols such as (4) Formation of fluororesin layer Fluorine resin on the surface of the inorganic coating layer
An oil layer was formed.   As a fluororesin layer, PTFE "Teflon" 855
Using J-21033 [Dupont Japan] aqueous dispersion,
In addition to this, high volume dielectric material barium titanate 34% by volume
And Ketchun Black (made by Lion), which is a conductive material
% By weight. After adjusting the viscosity, dip
Coating, drying and baking at 380 ° C x 30 min
To obtain a PTFE layer with a thickness of 2 μm and improved dielectric constant.
It was   An aqueous dispersion of PFA was used as the fluororesin layer, and the
After coating and drying by ip coating, 330 ℃ × 3
It was baked for 0 min to obtain a PFA layer having a film thickness of 0.5 μm.   As a fluororesin layer, FEP (ND-1, Daikin
(Manufactured by Kogyo Co., Ltd.)
Coating, drying, and baking at 330 ° C for 30min
Then, an FEP layer having a film thickness of 0.7 μm was obtained.   As a comparative example, the fluororesin layer is described in Example 1).
BaTiOs listed₃Content 65 volume% Ketchun Black 0
Dielectric constant improvement PT made by the same method with weight%
The FE layer was obtained.   As a comparative example, the experimental example and the fluororesin layer
And the film thickness of 5 μm described in 1) and
The formed PFA layer and FEP layer were obtained.

When the polyimide composite tubular article obtained as described above was incorporated into the electrophotographic apparatus shown in FIGS. 4 and 5 and operated, a clear image was obtained for each of the polyimide composite tubular article obtained as above. Also, there was no offset. However, each of the polyimide composite tubular products of and had poor image forming properties, and a problem that a clear image could not be obtained appeared.

(Example 2) The following table (Table 1) shows changes in the dielectric constant depending on the barium titanate concentration and carbon concentration for increasing the dielectric constant of the fluororesin which is the release / insulating layer.
The changes in the dielectric constant due to only the barium titanate concentration are shown below (Table 2).

[0040]

[Table 1]

[0041]

[Table 2]

As is clear from these results, the dielectric constant is improved as the barium titanate concentration is increased, but the original releasability of the fluororesin is lost as the barium titanate concentration is increased. However, the addition of a small amount of carbon was found to improve the dielectric constant even when the barium titanate concentration was low. From this fact, it is possible to control the charge amount on the surface of the fluororesin by controlling barium titanate, which is a high-dielectric constant material, and carbon, which is a conductive material, to an arbitrary concentration, and the releasability which is a characteristic of the fluororesin. A material having various properties such as water repellency, heat resistance, and insulation is possible.

The thus-obtained dielectric constant-enhancing fluororesin was good in forming and transferring a visible image, and it was possible to improve the image. Example 3 As a measurement of electrostatic characteristics, Table 2 shows the measurement results of the charging potential of the fluororesin layer of the tube. In addition, the charging potential is measured by the charger STATOR-20-0 (SH
ISHIDO ELECTROSTATIC LTD)
By applying 10 kV, the charging bar is reciprocated 30 times to charge the surface of the fluororesin, and a charging potential measuring device STATILON-M
(SHISHIDO ELECTROSTATIC L
The charge potential of the fluororesin surface was measured by TD).

The charging potential at this time is 0.5 μm with respect to −2 to −3 kV when the film thickness of the fluororesin layer is 5 μm.
Was -10 to -15 kV, and the thinner the film thickness, the higher the charging potential for charging. Further, since the charging potential and the amount of charged electric charge are in a proportional relationship of Q = CV, the amount of electric charges charged on the surface of the fluororesin is increased because the charging potential is increased, and the formation and transfer of a visible image are not good. Yes, it is possible to improve the image. The results are shown below (Table 3).

[0045]

[Table 3]

As described above, according to this embodiment, in the belt in which the formation and transfer of the visible image and the fixing onto the copy paper are performed in the same process, the adhesion between the conductive thin film layer and the fluororesin layer is high. In addition, by using a resin with a high dielectric constant and a thin film made of fluororesin, the amount of electrification on the fluororesin surface is remarkably increased, and visible image formation and transfer are good, and high density and clear images are obtained. Is obtained, and good fixing without offset can be performed.

[0047]

As described above, according to the present invention, a conductive thin film layer is provided on the surface of a tubular polyimide seamless base film, and an inorganic coating layer and a fluororesin layer are provided in this order on the conductive thin film layer. By installing in
Adhesion between the conductive layer and the fluororesin layer is high, and the dielectric constant of the fluororesin can be improved. Also, by using a thin film resin, the amount of surface charge is increased, a high density is formed in the formation and transfer of a visible image to form a clear visible image, and an offset is applied in fixing to copy paper. It is possible to realize a polyimide composite tubular article that is useful for a belt that performs good fixing without any damage.

[Brief description of drawings]

FIG. 1A is a cross-sectional view in the length direction of a polyimide composite tubular article according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view in the same circumferential direction.

FIG. 2 is a cross-sectional view showing cast molding of a polyimide seamless base film of one example of the present invention.

FIG. 3 (a) is a cross-sectional view of a polyimide seamless base film of one embodiment of the present invention in the length direction, and FIG. 3 (b) is a cross-sectional view of the polyimide seamless base film in the length direction and the vertical direction.

FIG. 4 is a cross-sectional view of a visible image forming / fixing device of an electrophotographic apparatus according to an exemplary embodiment of the present invention.

FIG. 5 is a cross-sectional view of a visible image transfer / fixing device of an electrophotographic apparatus according to an exemplary embodiment of the present invention.

[Explanation of symbols]

1 Polyimide base film 2 Conductive thin film layer 3 Inorganic coating layer 4 Fluororesin layer 5 Polyimide composite tubular products 10 Cylindrical inner mold 13 Polyimide precursor solution thin film 14 precursor solution 15 containers 16 Ring die (outer mold) 17 Polyimide tubular products 21 Copy paper 22 Paper supply roller 23 Backup roller 24 heating element holder 24 'heating element 25 Polyimide composite tubular product 26 Ejection roller 27,34 Static eliminator 28, 32 Cleaning device 29 Photosensitive drum 30 developer 31 drive roller 33 Transfer roller 41 Polyimide composite tubular product 42 recording head 43 Developer 44 Cleaning device 45 Static eliminator 46 heater 47 drive roller 48 tension roller 49 Pressure roller 50 Paper supply roller 51 copy paper 52 visible image (toner image) 53 Heat-fixed image (image)

Continuation of the front page (56) Reference JP-A-61-203460 (JP, A) JP-A-1-271759 (JP, A) JP-A-3-65958 (JP, A) JP-A-3-25471 (JP , A) JP-A-6-222695 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/05 G03G 5/02 101 G03G 15/16 101 G03G 15/20 101

Claims (7)

(57) [Claims] 1. A conductive thin film layer of 10 ³ Ω / □ or less is provided on the surface of a tubular seamless polyimide base film,
A polyimide composite tubular article having an inorganic coating layer and a fluororesin layer provided in this order on the conductive thin film layer. 2. The polyimide composite tubular article according to claim 1, wherein the conductive thin film layer is at least one layer selected from a metal vapor deposition layer, a plating layer, a sputtering layer and a coating layer. 3. The polyimide composite tubular article according to claim 1, wherein the inorganic coating layer is a thin film obtained by gelling a sol of an inorganic oxide. 4. The inorganic oxide is SiO ₂ , TiO ₂ , Z
The polyimide composite tubular article according to claim 3, which is at least one layer selected from rO ₂ and Al ₂ O ₃ . 5. The polyimide composite tubular article according to claim 1, wherein the fluororesin layer is a fluororesin layer containing a high dielectric constant material and a conductive material. 6. The polyimide composite tubular article according to claim 1, wherein the thickness of the polyimide seamless base film is in the range of 10 to 500 μm. 7. The polyimide composite tubular article according to claim 1, wherein the polyimide composite tubular article is used as a belt for forming and transferring a visible image of an image forming apparatus and fixing it to a copy paper in the same process.