JP2001350349A - Conductive endless belt and image forming device utilizing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive seamless belt provided with good strength, especially good durability against bending, good durability against creeping and furthermore, stability in size and an image forming device utilizing it in for the resin film belt utilized in the image forming device of a tandem method, an intermediate transfer method and a tandem intermediate transfer method. SOLUTION: In the conductive seamless belt for transfer and carrying of the tandem method where each toner image is sequentially transferred to a recording medium by circulating and driving the recording medium that is held by electrostatic attraction by a driving member, the substrate is made of thermoplastic polyarylate, polymer alloy of the thermoplastic polyarylate and thermoplastic resin or a polymer blend of the thermoplastic polyarylate and the thermoplastic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method such as a latent image holding member having an electrostatic latent image on the surface in an electrostatic recording process in an electrophotographic apparatus such as a copying machine or a printer or an electrostatic recording apparatus. Conductive endless belt (hereinafter simply referred to as "belt") used when transferring a toner image formed by supplying a developer to a body surface onto a recording medium such as paper, and image forming using the same Related to the device.

[0002]

2. Description of the Related Art Conventionally, in an electrostatic recording process in a copying machine, a printer, or the like, first, a photosensitive member (latent image holding member)
Surface is uniformly charged, an image is projected from the optical system onto the photoreceptor to eliminate the charging of the light-exposed portion, thereby forming an electrostatic latent image. Is supplied to form a toner image by electrostatic adhesion of toner, and the toner image is transferred to a recording medium such as paper, OHP, or photographic paper, thereby performing printing.

In this case, even in a color printer or a color copying machine, printing is basically performed according to the above-described process. In the case of color printing, magenta, yellow, cyan, and black toners are used. In order to reproduce the color tone, it is necessary to perform a process of superposing these toners at a predetermined ratio to obtain a necessary color tone, and several methods have been proposed for performing this process.

First, similarly to the case of performing monochrome printing, when a toner is supplied onto a photoreceptor to visualize an electrostatic latent image, the four colors of magenta, yellow, cyan, and black are used. There is a multiple development system in which development is performed by sequentially superimposing toner to form a color toner image on a photoconductor. According to this method, it is possible to configure the apparatus relatively compact, but in this method, there is a problem that it is very difficult to control the gradation and high image quality cannot be obtained.

Second, by providing four photosensitive drums and developing the latent images of the respective drums with magenta, yellow, cyan, and black toners, respectively, a magenta toner image, a yellow toner image, and a cyan toner image And four toner images of a black toner image, the photosensitive drums on which these toner images are formed are arranged in a line, and each toner image is sequentially transferred to a recording medium such as paper, and is superimposed on the recording medium. There is a tandem system for reproducing a color image. In this method, although a good image is obtained, four photosensitive drums, and a charging mechanism and a developing mechanism provided for each photosensitive drum are arranged in a line, so that the apparatus becomes large and expensive. Becomes

FIG. 2 shows an example of the configuration of a printing section of a tandem type image forming apparatus. A printing unit composed of the photosensitive drum 1, the charging roll 2, the developing roll 3, the developing blade 4, the toner supply roll 5, and the cleaning blade 6 corresponds to each of yellow Y, magenta M, cyan C, and black B toners. Drive rollers (drive members) 9
The toner is sequentially transferred onto the paper conveyed by the transfer conveyance belt 10 while being circulated by the printer to form a color image. Charging and charge elimination of the transfer conveyance belt are performed by a charge roll 7 and a charge elimination roll 8, respectively. An attraction roller (not shown) is used for charging the paper to attract the paper to the belt. By these measures, generation of ozone can be suppressed. The suction roller places the paper on the transfer conveyance belt from the conveyance path and performs electrostatic attraction to the transfer conveyance belt. Further, the sheet separation after the transfer can be performed only by the curvature separation by lowering the transfer voltage so as to weaken the attraction force between the sheet and the transfer conveyance belt.

The material of the transfer and transport belt 10 includes a resistor and a dielectric, each of which has advantages and disadvantages. Since the resistor belt retains electric charges for a short time, when used for tandem-type transfer, charge injection during transfer is small, and the voltage rise is relatively small even in continuous transfer of four colors. Electric charges are also discharged when repeatedly used for transferring the next sheet, so that an electrical reset is not required. However, since the resistance value changes due to environmental fluctuations, there are disadvantages in that the transfer efficiency is affected, and the sheet is easily affected by the thickness and width of the sheet.

On the other hand, in the case of a dielectric belt, there is no spontaneous emission of injected charges, and both injection and emission of charges must be controlled electrically. However, since the charges are stably held, the paper can be reliably absorbed and the paper can be transported with high accuracy. Since the dielectric constant has low dependence on temperature and humidity, the transfer process is relatively stable even in the environment. The disadvantage is that the charge is accumulated on the belt each time the transfer is repeated, which increases the transfer voltage.

Third, a recording medium such as paper is wound around a transfer drum and rotated four times, and magenta, yellow, cyan, and black on the photoreceptor are sequentially transferred to the recording medium for each revolution to reproduce a color image. There is also a transfer drum system that performs the transfer. According to this method, relatively high image quality can be obtained. However, when the recording medium is thick paper such as a postcard, it is difficult to wind it around the transfer drum, and the type of recording medium is limited. There is.

As compared with the above-mentioned multiple developing system, tandem system and transfer drum system, good image quality can be obtained, the apparatus is not particularly enlarged, and the type of recording medium is particularly limited. An intermediate transfer method has been proposed as a method without such a method.

That is, in this intermediate transfer system, an intermediate transfer member including a drum and a belt for temporarily transferring and holding a toner image on a photosensitive member is provided, and a magenta toner image, a yellow toner image, By arranging four photoconductors on which a cyan toner image and a black toner image are formed, and sequentially transferring the four color toner images onto the intermediate transfer member, a color image is formed on the intermediate transfer member. A color image is transferred onto a recording medium such as paper. Therefore, since the gradation is adjusted by superimposing the four color toner images, it is possible to obtain high image quality, and it is not necessary to arrange the photoconductors in a line as in the tandem method. In particular, there is no need to increase the size of the recording medium, and there is no need to wind the recording medium around the drum, so that the type of recording medium is not limited. There is also a tandem intermediate transfer system in which a tandem system and an intermediate transfer system are combined.

FIG. 3 illustrates an image forming apparatus using an endless belt-shaped intermediate transfer member as an intermediate transfer member as an apparatus for forming a color image by the intermediate transfer method.

In FIG. 3, reference numeral 11 denotes a drum-shaped photosensitive member.
It rotates in the direction of the arrow in the figure. The photoconductor 11 is charged by the primary charger 12, and then the exposed portion is erased by image exposure 13, and an electrostatic latent image corresponding to the first color component is formed on the photoconductor 11,
Further, the electrostatic latent image is developed by the developing device 41 with the first color magenta toner M, and the first color magenta toner image is formed on the photoconductor 11. Next, the toner image is circulated and driven by the driving roller (driving member) 30 so that the photosensitive member 1 is driven.
The toner image is transferred to the intermediate transfer member 20 that rotates while circulating in contact with the intermediate transfer member 20. In this case, the transfer from the photoconductor 11 to the intermediate transfer member 20 is performed by a primary transfer bias applied from the power supply 61 to the intermediate transfer member 20 at a nip portion between the photoconductor 11 and the intermediate transfer member 20. This intermediate transfer member 2
After the magenta toner image of the first color is transferred to 0, the surface of the photoconductor 11 is cleaned by the cleaning device 14, and the development transfer operation of the photoconductor 11 in the first rotation is completed. Thereafter, the photoconductor rotates three times, and the developing device 42
The cyan toner image of the second color, the yellow toner image of the third color, and the black toner image of the fourth color are sequentially formed on the photoreceptor 11 by sequentially using No. to No. 44, and are superimposedly transferred to the intermediate transfer member 20 every rotation. Then, a composite color toner image corresponding to the target color image is formed on the intermediate transfer member 20. In the apparatus shown in FIG. 3, the developing units 41 to 44 are sequentially switched for each rotation of the photoconductor 11, so that development with the magenta toner M, the cyan toner C, the yellow toner Y, and the black toner B is performed sequentially. Has become.

Next, a transfer roller 25 contacts the intermediate transfer member 20 on which the composite color toner image is formed, and a recording medium 26 such as paper is fed from a paper feed cassette 19 to a nip portion thereof. At the same time, the secondary transfer bias is
The composite color toner image is transferred from the intermediate transfer member 20 onto the recording medium 26, and is fixed by heating to form a final image. After transferring the composite color toner image onto the recording medium 26, the transfer residual toner on the surface of the intermediate transfer member 20 is removed by the cleaning device 35, and the intermediate transfer member 20 returns to the initial state and prepares for the next image formation.

Conventionally, as such an endless belt-shaped intermediate transfer member 20, a semiconductive resin film belt and a rubber belt having a fiber reinforcement have been mainly used. Among these, as a semiconductive resin film belt, a blend of carbon black and polycarbonate is conventionally known, but recently, a polyalkylene terephthalate based on improved durability against bending has been used. Resin film belt as material (Japanese Patent Laid-Open No. 8-99374)
Japanese Patent Application Laid-Open No. 11-17 / 1999 and a resin film belt using a thermoplastic polyimide as a base material with improved elasticity.
No. 0389) has been proposed.

[0016]

In an image forming apparatus of a tandem system, an intermediate transfer system and a tandem intermediate transfer system using a conductive endless belt, the conductive endless belt is repeatedly used continuously in terms of mechanism. It is required to have endurable strength, particularly bending durability and creep resistance.

Although some semiconductive resin film belts have been put to practical use so far, as the performance of the image forming apparatus has been improved, it is required that the belt satisfy the above-mentioned required characteristics better. Have been.

Accordingly, an object of the present invention is to provide a resin film belt used in an image forming apparatus of a tandem system, an intermediate transfer system, and a tandem intermediate transfer system, which has good strength,
In particular, it is an object of the present invention to provide a conductive endless belt having good bending durability, creep resistance, and dimensional stability, and an image forming apparatus using the same.

[0019]

The present inventors have conducted intensive studies on various synthetic resins to solve the above-mentioned problems, and as a result, have found that a thermoplastic polyarylate resin or a polymer alloy or polymer thereof as a base material of a conductive endless belt. It has been found that the above object can be achieved by using a blend, and the present invention has been completed. That is,
The present invention is as described below.

(1) A recording medium held by electrostatic attraction is circulated by a driving member and conveyed to four types of image forming bodies, and a tandem type transfer in which respective toner images are sequentially transferred to the recording medium. The conductive endless belt for conveyance, characterized in that the base material is a thermoplastic polyarylate, a polymer alloy of a thermoplastic polyarylate and a thermoplastic resin, or a polymer blend of a thermoplastic polyarylate and a thermoplastic resin. It is a conductive endless belt.

(2) The toner image formed on the surface of the image forming member is temporarily transferred to its own surface by being circulated and driven by a driving member, disposed between the image forming member and the recording medium. In a conductive endless belt for an intermediate transfer member for transferring an ink to a recording medium, a thermoplastic polyarylate, a polymer alloy of a thermoplastic polyarylate and a thermoplastic resin, or a polymer blend of a thermoplastic polyarylate and a thermoplastic resin Is a conductive endless belt characterized in that it is used as a base material.

(3) In the conductive endless belt according to (1) or (2), the polymer alloy of the thermoplastic polyarylate and the thermoplastic resin is a polymer alloy of the thermoplastic polyarylate and the thermoplastic polycarbonate. It is a conductive endless belt.

(4) In the conductive endless belt of (1) or (2), the polymer alloy of the thermoplastic polyarylate and the thermoplastic resin is a polymer alloy of the thermoplastic polyarylate and the thermoplastic polyethylene terephthalate. There is a conductive endless belt.

(5) The conductive endless belt according to any one of the above (1) to (4), wherein a conductive material is added as a functional component.

(6) The conductive endless belt according to (5), wherein the conductive material is carbon black and 0.1 to 100 parts by weight is added to 100 parts by weight of the resin component. is there.

(7) In the conductive endless belt according to any one of the above (1) to (6), the volume resistance value is 10 ⁶ to 10 ⁶ .
The conductive endless belt has a resistance of 10 ¹³ Ω · cm.

(8) In the conductive endless belt according to any one of (1) to (7), a conductive endless belt having a fitting portion for fitting with the driving member is provided on a surface on a side in contact with the driving member. It is a belt.

(9) In the conductive endless belt according to the above (8), the fitting portion is a conductive endless belt that is a ridge continuously protruded along a rotation direction.

(10) An image forming apparatus using the conductive endless belt according to any one of (1) to (9).

The above-described conductive endless belt of the present invention has good strength, particularly good bending durability and creep resistance, and has high dimensional accuracy. Further, in the case where a fitting portion is provided for fitting the drive member and the conductive endless belt with each other, a phenomenon that the conductive endless belt stretched on two or more shafts is shifted in the width direction with rotation is prevented. can do. Further, according to the image forming apparatus of the present invention, a good image can be provided without causing a defect even when used for a long time.

[0031]

Embodiments of the present invention will be described below. The conductive endless belt is generally classified into a belt having a joint and a belt having no joint (a so-called seamless belt). In the present invention, any belt may be used. As described above, the conductive endless belt of the present invention can be used as a transfer member of a tandem system, an intermediate transfer system, and a tandem intermediate transfer system. When the conductive endless belt of the present invention is, for example, a transfer / conveying belt indicated by reference numeral 10 in FIG. 2, it is driven by a driving member such as a driving roller 9;
Along with this, the toner is sequentially transferred onto the recording medium conveyed, and a color image is formed.

In the case where the conductive endless belt of the present invention is, for example, an intermediate transfer member indicated by reference numeral 20 in FIG. 3, the belt is circulated and driven by a driving member such as a driving roller 30 to form a photosensitive drum (latent image). The photosensitive drum 11 is disposed between the holding member 11 and a recording medium 26 such as paper.
The toner image formed on the surface is temporarily transferred and held, and then transferred to the recording medium 26. The apparatus shown in FIG. 3 performs color printing by the intermediate transfer method as described above.

The thermoplastic polyarylate which can be used for the conductive endless belt of the present invention is an engineering plastic having excellent impact resistance and dimensional stability and excellent elastic recovery properties, and is easily available on the market. For example, U-100 manufactured by Unitika Ltd. can be typically mentioned. By using such a thermoplastic polyarylate as a base material of a conductive endless belt, there is no variation in resistance, strength, particularly excellent bending durability and creep resistance, and a conductive endless belt having high dimensional accuracy. can get.

In the present invention, a polymer alloy or a polymer blend of a thermoplastic polyarylate and a thermoplastic resin may be used. Particularly, a polymer of a thermoplastic polyarylate and a thermoplastic polycarbonate or a thermoplastic polyethylene terephthalate may be used. Alloys are preferred. Such a polymer alloy and a polymer blend of a thermoplastic polyarylate and a thermoplastic resin can also be obtained on the market. For example, P-3001 manufactured by Unitika Ltd. as an alloy with polycarbonate, and an alloy with polyethylene terephthalate are available. U-8000 manufactured by Unitika Ltd. as a typical example.

The thermoplastic polyarylate, which is the base material of the conductive endless belt, or the polymer alloy or the polymer blend of the thermoplastic endless belt and the thermoplastic resin is added with a conductive material as a functional component to impart conductivity. Can be adjusted. In this case, the conductive material is not particularly limited. Cation surfactants such as quaternary ammonium, such as borofluoride, sulfate, ethosulfate, benzyl halide (benzyl bromide, benzyl chloride, etc.); aliphatic sulfonic acids, higher alcohols Sulfate ester, higher alcohol ethylene oxide addition sulfate,
Anionic surfactants such as higher alcohol phosphate esters; amphoteric surfactants such as various betaines; antistatic agents such as nonionic antistatic agents such as higher alcohol ethylene oxide, polyethylene glycol fatty acid esters, and polyhydric alcohol fatty acid esters Agent, LiCF ₂ SO ₂ ,
Metal salts of the first group of the periodic table, such as NaClO ₄ , LiBF ₄ , and NaCl; metal salts of the second group of the periodic table, such as Ca (ClO ₄ ) ₂ ; and active hydrogen in which these antistatic agents react with isocyanates And a group having at least one group (e.g., a hydrogen group, a carboxyl group, or a primary or secondary amine group). Further, ions such as complexes of these with polyhydric alcohols (1,4-butanediol, ethylene glycol, polyethylene glycol, propylene glycol, etc.) or derivatives thereof, or complexes with ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc. Conductive agent; conductive carbon such as ketjen black, acetylene black; SAF, ISAF, HA
Carbon for rubber such as F, FEF, GPF, SRF, FT, MT; carbon for oxidized color ink, pyrolytic carbon, natural graphite, artificial graphite, etc .; tin oxide, titanium oxide, zinc oxide, nickel, copper And metal oxides; conductive polymers such as polyaniline, polypyrrole, and polyacetylene.

When the conductive material is carbon black, the amount of these conductive materials added to the base material is 100
0.1 to 100 parts by weight, preferably 1 to 100 parts by weight
It can be 50 parts by weight, whereby the volume resistance value of the elastic material layer is 10 ⁶ to 10 ¹³ Ω · cm, preferably 10 ⁷ to
It can be adjusted to 10 ¹² Ω · cm.

In the present invention, other functional components can be added in addition to the above components within a range not to impair the effects of the present invention. For example, various fillers, coupling agents, antioxidants , Lubricants, surface treatment agents, pigments, UV absorbers, antistatic agents, dispersants, neutralizers, foaming agents, crosslinkers,
A compatibilizer or the like can be appropriately blended.

The thickness of the conductive endless belt of the present invention is appropriately selected according to the form of the transfer / transport belt or the intermediate transfer member, but is preferably 50 to 20.
It is within the range of 0 μm.

The conductive endless belt of the present invention has, as shown by a dashed line in FIG. 1, a side in contact with a driving member such as the driving roller 9 or the driving roller 30 in FIG. May be formed with a fitting part (not shown) formed on the driving member, and the conductive endless belt of the present invention is provided with such a fitting part. By running this by fitting it with a fitting portion (not shown) provided on the drive member, it is possible to prevent the conductive endless belt from shifting in the width direction.

In this case, the fitting portion is not particularly limited, but as shown in FIG. 1, is formed as a continuous ridge along the circumferential direction (rotation direction) of the belt, which is formed by a driving roller or the like. It is preferable to fit into a groove formed along the circumferential direction on the peripheral surface of the driving member.

FIG. 1 (a) shows an example in which one continuous ridge is provided as a fitting portion. However, this fitting portion has a large number of protrusions formed in the circumferential direction (rotation direction) of the belt. May be provided in a line along the line, and two or more fitting portions may be provided (FIG. 1B), or may be provided at the center in the width direction of the belt. Further, a groove is formed along the circumferential direction (rotational direction) of the belt as the fitting portion instead of the ridge shown in FIG. 1 and is formed along the circumferential direction on the circumferential surface of the driving member such as the driving roller. You may make it fit with the convex part which did.

Although the conductive endless belt of the present invention is not particularly limited, it has a surface roughness of 10 μm or less, particularly 6 μm or less, and more preferably 3 μm or less in terms of JIS 10-point average roughness Rz.
It is preferable that the thickness be not more than μm.

As the image forming apparatus of the present invention using the conductive endless belt of the present invention, a tandem type shown in FIG. 2, an intermediate transfer type shown in FIG. 3, or a tandem intermediate transfer type is used. However, the present invention is not limited to these. In the case of the apparatus shown in FIG. 3, a voltage can be applied from a suitable power supply 61 to the drive roller or drive gear for rotating the intermediate transfer member 20 of the present invention. Application conditions, such as application of alternating current, can be selected as appropriate.

Furthermore, the method for producing the conductive endless belt of the present invention is not particularly limited. For example, a resin component (thermoplastic polyarylate or a polymer alloy or a polymer of the thermoplastic resin and a thermoplastic resin) is mixed by a twin-screw kneader. Blend) and a functional component such as a conductive material can be kneaded, and the resulting kneaded product can be extruded using a ring die to produce the mixture. Alternatively, a powder coating method such as electrostatic coating, a dipping method or a centrifugal casting method can be suitably adopted.

[0045]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. Example 1 Thermoplastic polyarylate (U-10, manufactured by Unitika Ltd.)
0) 100 parts by weight and 30 parts by weight of Electrified Black (manufactured by Denki Kagaku Kogyo Co., Ltd.) were kneaded with a biaxial kneader,
By extruding the obtained kneaded material, an inner diameter of 245
Thus, a conductive endless belt having dimensions of mm, thickness 100 μm, and width 250 mm was obtained. The number of times the conductive endless belt was bent was measured using a kneading fatigue tester manufactured by Toyo Seiki Co., Ltd. Further, the amount of tensile creep was measured at a temperature of 25 ° C. for 1200 hours in accordance with JIS K7115 test method. Further, the measurement of the volume resistivity was carried out at a temperature of 20 ° C. and a relative humidity of 50% at a measurement voltage of 100%.
V, ADVANTETE (ADVANTE)
ST) manufactured by connecting a sample chamber R12704A to a resistance meter R8340A.

Example 2 The measurement was performed in the same manner as in Example 1 except that a thermoplastic polyarylate alloy (U-8000, manufactured by Unitika Ltd.) was used instead of the thermoplastic polyarylate.

Comparative Example 1 The procedure of Example 1 was repeated except that a polycarbonate resin (manufactured by Teijin Chemicals Ltd., Panlite K1300Y) was used in place of the thermoplastic polyarylate and 30 parts by weight of FEF carbon (manufactured by Asahi Carbon Co., Ltd.). It measured similarly to 1.

The conductive endless belts of the above embodiment and the comparative example were mounted on a tandem type image forming apparatus using the transfer / conveying belt shown in FIG. 2, and the transfer operation was repeated to endure 100,000 sheets of A4 paper. The test was performed. At this time, the surface of the conductive endless belt was observed as needed to confirm the presence or absence of cracks. The results of this test were evaluated for image properties and surface properties. Table 1 below shows the above volume resistance values, the measured values of the number of times of bending, and the results of the durability test. In the table, the number of times of bending was set to 100 or more in Examples, and the number of times of bending was indicated by an index as the number of times of bending.

[0049]

[Table 1]

From the results of the above measurements and tests, it was confirmed that the conductive endless belts of the examples had remarkable advantages in bending durability and creep resistance.

[0051]

As described above, according to the present invention, it is possible to provide a conductive endless belt having excellent strength, particularly excellent bending durability and creep resistance, and having high dimensional accuracy. Further, according to the image forming apparatus of the present invention using the conductive endless belt of the present invention, it is possible to obtain a good image without any defect even in long-term use.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view in the width direction of a conductive endless belt according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a tandem type image forming apparatus using a transfer conveyance belt as an example of the image forming apparatus of the present invention.

FIG. 3 is a schematic view illustrating an image forming apparatus of an intermediate transfer type using an intermediate transfer member as another example of the image forming apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor drum 2 Charging roll 3 Developing roll 4 Developing blade 5 Toner supply roll 6 Cleaning blade 7 Charging roll 8 Static elimination roll 9 Driving roller (driving member) 10 Transfer conveyor belt 11 Photoconductor 12 Primary charger 13 Image exposure 14, 35 Cleaning device 19 Paper feed cassette 20 Intermediate transfer member 25 Transfer roller 26 Recording medium 29, 61 Power supply 30 Drive roller 41, 42, 43, 44 Developing device

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08L 101/00 C08L 101/00 G03G 15/01 114 G03G 15/01 114A 114B

Claims (10)

[Claims] 1. A tandem transfer and conveyance method in which a recording medium held by electrostatic attraction is circulated by a driving member and conveyed to four types of image forming bodies, and each toner image is sequentially transferred to the recording medium. A conductive endless belt for use, wherein the base material is a thermoplastic polyarylate, a polymer alloy of a thermoplastic polyarylate and a thermoplastic resin, or a polymer blend of a thermoplastic polyarylate and a thermoplastic resin. Sex endless belt. 2. A toner image formed on a surface of the image forming member, which is disposed between the image forming member and a recording medium and is circulated by a driving member to temporarily transfer and hold the toner image formed on the surface of the image forming member. In a conductive endless belt for an intermediate transfer member for transferring to a recording medium, a thermoplastic polyarylate, a polymer alloy of a thermoplastic polyarylate and a thermoplastic resin, or a polymer blend of a thermoplastic polyarylate and a thermoplastic resin is used. A conductive endless belt, which is used as a base material. 3. The conductive endless belt according to claim 1, wherein the polymer alloy of the thermoplastic polyarylate and the thermoplastic resin is a polymer alloy of a thermoplastic polyarylate and a thermoplastic polycarbonate. 4. The conductive endless belt according to claim 1, wherein the polymer alloy of the thermoplastic polyarylate and the thermoplastic resin is a polymer alloy of a thermoplastic polyarylate and a thermoplastic polyethylene terephthalate. 5. The conductive endless belt according to claim 1, wherein a conductive material is added as a functional component. 6. The conductive endless belt according to claim 5, wherein the conductive material is carbon black, and 0.1 to 100 parts by weight is added to 100 parts by weight of the resin component. 7. The conductive endless belt according to claim 1, which has a volume resistance value of 10 ⁶ to 10 ¹³ Ω · cm. 8. The conductive endless belt according to claim 1, further comprising a fitting portion fitted on the driving member on a surface in contact with the driving member. 9. The conductive endless belt according to claim 8, wherein the fitting portion is a ridge continuously projecting in a rotation direction. 10. An image forming apparatus using the conductive endless belt according to any one of claims 1 to 9.