JP2002116629A - Conductive endless belt and image forming device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive seamless belt which is the resin belt film used for image forming devices of a tandem system, intermediate transfer system and tandem intermediate transfer system and has good strength and more particularly good bending durability and an adequate modulus of elasticity in combination and an image forming device using the same. SOLUTION: The conductive seamless belt for transfer and transportation of the tandem system which is circulated and driven by driving members to transport the recording media held by electrostatic attraction to four kinds of image forming bodies and successively transfers respective toner images to the recording media is formed by using a thermosetting polyurethane resin prepared by compounding 1 to 30 pts.wt. isocyanate component with 100 pts.wt. polyester polyol as a base material.

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, conventionally, a mixture of polycarbonate and carbon black is known, but recently, a polyalkylene terephthalate based on an improvement in durability against bending has been used. Resin film belt as material (Japanese Patent Application Laid-Open No.
No. 4) or a resin film belt using a thermoplastic polyimide as a base material having improved elasticity (Japanese Patent Laid-Open No. 11-1).
No. 70389).

[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, especially bending durability, and appropriate elastic modulus.

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 and an appropriate elastic modulus, and an image forming apparatus using the same.

[0019]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on various synthetic resins to solve the above-mentioned problems, and have found that a specific thermosetting resin is used as a base material of a conductive endless belt. The inventors have found that the object can be achieved, and have completed the present invention. 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. In the conductive endless belt for conveyance, a conductive endless belt characterized in that a base material is a thermosetting polyurethane resin obtained by mixing 1 to 30 parts by weight of an isocyanate resin component with respect to 100 parts by weight of a polyester polyol resin component. is there.

(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. Is transferred to a recording medium, the isocyanate resin component is 1 to 100 parts by weight of the polyester polyol resin component in the conductive endless belt for the intermediate transfer member.
A conductive endless belt characterized by using a thermosetting polyurethane resin mixed with 30 parts by weight as a base material.

(3) The conductive endless belt according to (1) or (2), wherein a conductive material is added as a functional component.

(4) The conductive endless belt according to (3), 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.

(5) In the conductive endless belt according to any one of the above (1) to (4), the dynamic elastic modulus E 'is 10
It is a conductive endless belt larger than ⁸ Pa.

(6) In the conductive endless belt according to any one of the above (1) to (5), the volume resistance value is 10 ⁶ to
The conductive endless belt has a resistance of 10 ¹³ Ω · cm.

(7) In the conductive endless belt according to any one of (1) to (6), a conductive endless belt having a fitting portion for fitting with the driving member is provided on a surface in contact with the driving member. It is a belt.

(8) In the conductive endless belt according to (7), the fitting portion is a conductive endless belt that is a protruding ridge continuously protruded along a rotation direction.

(9) An image forming apparatus using the conductive endless belt according to any one of (1) to (8).

The above-mentioned conductive endless belt of the present invention has both good strength, particularly good bending durability, and an appropriate elastic modulus. 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.

[0030]

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.

When the conductive endless belt of the present invention is, for example, an intermediate transfer member indicated by reference numeral 20 in FIG. 3, it is circulated 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.

In the thermosetting polyurethane resin used as the base material in the conductive endless belt of the present invention, the isocyanate resin content is 1 to 100 parts by weight of the polyester polyol resin component as the polyol component.
30 parts by weight, preferably 2 to 20 parts by weight are blended. Thereby, it is possible to obtain a conductive endless belt having both strength, particularly good bending durability, and a suitable elastic modulus. Here, the “resin content” does not represent a ratio in the weight of the coating material but a weight ratio of only the polyol component and the isocyanate component excluding other components.

The polyester polyol as the polyol component in the present invention is not limited as long as it satisfies the strength of the coating film. Examples of commercially available products include Byron 1400 (a modified copolymerized polyester resin) manufactured by Toyobo Co., Ltd.

The isocyanate component is not particularly limited, and is generally used for TDI, MDI, crude MDI.
(Polymeric-MDI), MDI modified, and TD
A special isocyanate other than the I-modified isocyanate may be used. As a special isocyanate,
For example, 1,5-naphthalene diisocyanate, tolidine diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, p-phenylene diisocyanate, transcyclohexane 1,4 diisocyanate, xylylene diisocyanate (XDI), hydrogenated-XDI, hydrogenated-MDI, lysine diisocyanate ,
Triphenylmethane triisocyanate, tris (isocyanate phenyl) thiophosphate, tetramethyl xylene diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanatomethyloctane, 1,3 6,6-hexamethylene triisocyanate, bicycloheptane triisocyanate,
Trimethylhexamethylene diisocyanate and the like can be mentioned, and these are also preferably used.

In the present invention, the conductivity can be imparted or adjusted by adding a conductive material as a functional component to the thermosetting polyurethane resin as the base material. In this case, the conductive material is not particularly limited. Cationic surfactants such as quaternary ammonium, such as borofluoride, sulfate, ethosulfate, and benzyl halide (eg, benzyl chloride and benzyl chloride); aliphatic sulfonic acids, higher alcohols Anionic surfactants such as sulfates, higher alcohol ethylene oxide addition sulfates and higher alcohol phosphates; amphoteric surfactants such as various betaines; higher alcohols ethylene oxide and polyethylene glycol Fatty acid esters, polyhydric antistatic agent such as a nonionic antistatic agents such as alcohol fatty acid _{ester, LiCF 2 SO 2, NaClO 4} , LiB
Metal salts of the first group of the periodic table such as F ₄ and NaCl; Ca (C
a metal salt of Group 2 of the periodic table such as 10 ₄ ) _2; and one group in which these antistatic agents have an active hydrogen (such as a hydrogen group, a carboxyl group, or a primary to secondary amine group) that reacts with isocyanate. And the like. 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, HAF, FEF, GPF,
Rubber carbon such as SRF, FT, MT; carbon for oxidized color ink, pyrolytic carbon, natural graphite, artificial graphite, etc .; metals and metal oxides such as tin oxide, titanium oxide, zinc oxide, nickel and copper Products; conductive polymers such as polyaniline, polypyrrole, and polyacetylene can be exemplified. Preferably, carbon black is used.

The amount of the conductive material to be added to the substrate can be 0.1 to 100 parts by weight, preferably 1 to 50 parts by weight, based on 100 parts by weight of the resin component. Can be adjusted to 10 ⁶ to 10 ¹³ Ω · cm, preferably 10 ⁷ to 10 ¹² Ω · cm.

Further, in the present invention, other functional components can be added in addition to the above components, as long as the effects of the present invention are not impaired. For example, various fillers, coupling agents, antioxidants, etc. Agents, lubricants, surface treatment agents, pigments, ultraviolet absorbers, antistatic agents, dispersants, neutralizers, foam stabilizers, foaming agents, crosslinking agents, compatibilizers, chain extenders, flame retardants, stabilizers, etc. Can be appropriately blended.

The conductive endless belt of the present invention preferably has a dynamic elastic modulus E 'of greater than 10 ⁸ Pa, and more preferably has a dynamic elastic modulus in the range of 10 ^8.8 to 10 ¹⁰ Pa. And This prevents the belt from being stretched when tension is applied, prevents image defects such as color misregistration during repeated use, and realizes a belt having good image quality.

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)
In the above, an example in which one continuous ridge is provided as a fitting portion is shown, but this fitting portion is formed by arranging a large number of protrusions in a line along the circumferential direction (rotation direction) of the belt. Alternatively, two or more fitting portions may be provided (FIG. 1B), or 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.

The conductive endless belt of the present invention
Although not particularly limited, the surface roughness is set to JIS10
The point average roughness Rz is preferably 10 μm or less, particularly preferably 6 μm or less, and more preferably 3 μm or less. The thickness of the 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 in the range of 50 to 200 μm.

The conductive endless belt of the present invention is manufactured by forming a coating liquid using the above-described base material and additives using a solvent and forming a coating film by a dip (DIP) method. The layer configuration can be a single layer or a multilayer configuration as appropriate, and is not particularly limited. As the solvent that can be used for forming such a coating liquid, a conventional solvent can be used, and examples thereof include lower alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone; and toluene and xylene. And a mixed solvent thereof.

As an 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. Can be illustrated,
It 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.

[0044]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. Example A coating material was prepared with the following composition, and a sample was prepared by a solvent immersion method (dipping method). Curing condition is 120 ° C
For 1 hour, remove the cured molded product,
A conductive endless belt having a thickness of 5 mm, a width of 250 mm, and a thickness of 100 μm was obtained. When this conductive endless belt was mounted on an actual machine and an image drawing test was performed, good performance was obtained without any problem. 100 parts by weight of polyester polyol (OH value: about 4, Byron UR1400 manufactured by Toyobo) 0.8 part by weight of isocyanate (NCO% 13.2, Coronate L manufactured by Nippon Polyurethane Co.) 100 parts by weight of methyl ethyl ketone (MEK) 100 parts by weight of carbon black (Asahi Carbon Manufactured by FEF) 4.5 parts by weight

Comparative Example As a comparative example, an acrylic resin was used as a base resin,
A paint was prepared with the following composition, and a conductive endless belt having the same dimensions as the example was manufactured in the same procedure as in the example. Acrylic polyol (OH value about 134, manufactured by Mitsubishi Rayon Co., Ltd., Dianal LR200) 100 parts by weight Isocyanate (NCO% 21, Nippon Polyurethane Co., Coronate HX) 57.3 parts by weight Methyl ethyl ketone (MEK) 460.0 parts by weight Part Carbon black (made by Asahi Carbon, FEF) 5.0 parts by weight

With respect to the belts of the samples obtained in the above Examples and Comparative Examples, the specific volume resistivity was measured under the following conditions. Measurement environment: temperature 20 ° C., relative humidity 50% Measurement voltage: 100 V Measurement device: Advantest's resistance meter R8340A connected to sample chamber R12704A

The dynamic elastic modulus E ′ was measured by Rheolegraph soli manufactured by Toyo Seiki Co., Ltd.
d Sample shape, width 5 using rheology meter
mm, thickness 0.2mm, length 30mm (distance between chucks), initial stretching 5%, amplitude ± 1%, frequency 1Hz,
The measurement was performed under measurement conditions at room temperature of 23 ° C.

Further, the number of times of bending until the belt was broken was measured using an MIT kneading fatigue tester manufactured by Toyo Seiki Co., Ltd. This result, together with the above measurement results, is
The results are shown in Table 1 below in comparison with a C (polycarbonate) belt.

[0049]

[Table 1]

[0050]

As described above, according to the present invention, it is possible to obtain a conductive endless belt having both good strength, especially bending durability, and excellent elastic modulus. According to the image forming apparatus of the present invention using the conductive endless belt, it is possible to provide a good image which does not cause a defect even when used for a long time.

[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 showing an intermediate transfer device 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 (drive 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

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H030 AB02 BB23 BB42 BB44 2H032 BA09 BA18 BA23 4J002 BM00X CE00X CK03W CM05X DA036 DA076 DA086 DD006 DD046 DD056 DE046 DE096 DE106 DE136 DG046 DK006 EB126 EB136 EB136 E030E04E03 DB03 DQ04 HA01 HA07 HB03 HB15 HC03 HC12 HC13 HC15 HC17 RA11 RA14

Claims (9)

[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 as a base material, comprising a thermosetting polyurethane resin obtained by mixing 1 to 30 parts by weight of an isocyanate resin component with respect to 100 parts by weight of a polyester polyol resin. 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. A conductive endless belt for an intermediate transfer member for transferring to a recording medium, wherein a base material is a thermosetting polyurethane resin obtained by mixing 1 to 30 parts by weight of an isocyanate resin component with respect to 100 parts by weight of a polyester polyol resin component. A conductive endless belt. 3. The conductive endless belt according to claim 1, wherein a conductive material is added as a functional component. 4. The conductive endless belt according to claim 3, 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. 5. The conductive endless belt according to claim 1, wherein the dynamic elastic modulus E ′ is larger than 10 ⁸ Pa. 6. The conductive endless belt according to claim 1, which has a volume resistance value of 10 ⁶ to 10 ¹³ Ω · cm. 7. 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. 8. The conductive endless belt according to claim 7, wherein the fitting portion is a ridge continuously projecting along the rotation direction. 9. An image forming apparatus using the conductive endless belt according to claim 1. Description: