JP2007192996A - Conductive endless belt and image forming apparatus using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive endless belt superior in productivity by possessing a strength and various required performances of charge characteristics or the like and satisfying a required performance from a point of glossiness, and to provide an image forming apparatus using it. <P>SOLUTION: The conductive endless belt has a laminated structure successively having at least a base layer and the outermost layer from inside, and is formed by coextrusion. In the conductive endless belt, the base layer mainly comprises an acrylonitrile-butadiene-styrene resin, and the outermost layer mainly comprises a polystyrene resin or an acrylonitrile-styrene resin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention supplies a developer to the surface of an image forming body such as a latent image holding body holding 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. The present invention relates to a conductive endless belt (hereinafter also simply referred to as “belt”) used when transferring a toner image formed in this way onto a recording medium such as paper, and an image forming apparatus using the same.

  Conventionally, in an electrostatic recording process in a copying machine, a printer, etc., first, the surface of a photosensitive member (latent image holding member) is uniformly charged, and an image is projected onto the photosensitive member from an optical system and exposed to light. An electrostatic latent image is formed by erasing the charged portion, and then toner is supplied to the electrostatic latent image to form a toner image by electrostatic adhesion of the toner, which is formed on paper, OHP, photographic paper For example, a method of printing by transferring to a recording medium such as the above is employed.

  In this case, color printers and color copiers basically print according to the above process, but in the case of color printing, the color tone is reproduced using toners of four colors, magenta, yellow, cyan, and black. Therefore, a process for obtaining a necessary color tone by superimposing these toners at a predetermined ratio is required, and several methods have been proposed for performing this process.

  First, as in the case of monochrome printing, when the electrostatic latent image is visualized by supplying toner onto the photosensitive member, the four colors of magenta, yellow, cyan, and black are sequentially added. There is a multi-development system in which development is performed by superimposing and a color toner image is formed on the photoreceptor. According to this method, it is possible to configure the apparatus relatively compactly, but this method has a problem in that it is very difficult to control gradation and high image quality cannot be obtained.

  Second, four photosensitive drums are provided, and the latent images on each drum are developed with magenta, yellow, cyan, and black toners, respectively, so that a magenta toner image, a yellow toner image, a cyan toner image, and a black toner image are obtained. By forming four toner images of the toner image, arranging the photosensitive drums on which these toner images are formed in a line, sequentially transferring the toner images onto a recording medium such as paper, and superimposing them on the recording medium, a color image is formed. There is a tandem method to reproduce. Although this method can obtain a good image, the four photosensitive drums, the charging mechanism and the developing mechanism provided for each photosensitive drum are arranged in a line, and the apparatus becomes large and expensive. It becomes.

  FIG. 2 shows a configuration example of the printing unit of the tandem 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 toner of yellow Y, magenta M, cyan C, and black B 4 The toner images are sequentially transferred onto a sheet that is circulated by a driving roller (driving member) 9 and conveyed by a transfer conveying belt 10 to form a color image. Charging and discharging of the transfer / conveying belt are performed by the charging roll 7 and the discharging roll 8, respectively. Further, a suction roller (not shown) is used for charging the paper for sucking the paper onto the belt. Owing to 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 adsorption on the transfer conveyance belt. Further, the sheet separation after the transfer can be performed only by the curvature separation by lowering the transfer voltage to weaken the adsorption force between the sheet and the transfer conveyance belt.

  As materials for the transfer / conveyance belt 10, there are a resistor and a dielectric, each having advantages and disadvantages. Since the resistor belt can hold charges for a short time, when it is used for tandem transfer, there is little charge injection during transfer, and the voltage rise is relatively small even during continuous transfer of four colors. In addition, when it is repeatedly used for the transfer of the next sheet, the electric charge is released, and no electrical reset is required. However, since the resistance value changes due to environmental fluctuations, there are disadvantages such as affecting transfer efficiency and being easily influenced by the thickness and width of the paper.

  On the other hand, in the case of a dielectric belt, there is no spontaneous release of injected charge, and both charge injection and discharge must be electrically controlled. However, since the charge is stably held, the sheet can be adsorbed reliably and can be conveyed with high accuracy. Since the dielectric constant is less dependent on temperature and humidity, the transfer process is relatively stable to the environment. The disadvantage is that the transfer voltage increases because charges are accumulated on the belt each time the transfer is repeated.

  Thirdly, a recording medium such as paper is wound around a transfer drum, and this is rotated four times, and magenta, yellow, cyan, and black on the photosensitive member are sequentially transferred to the recording medium every rotation to reproduce a color image. There is also a method. According to this method, a relatively high image quality can be obtained. However, when the recording medium is a cardboard such as a postcard, it is difficult to wind the recording medium around the transfer drum, and the type of the recording medium is limited. There is.

  A system in which good image quality is obtained with respect to the multiple development system, tandem system and transfer drum system, the apparatus is not particularly large, and the type of recording medium is not particularly limited. As an example, an intermediate transfer method has been proposed.

  That is, in this intermediate transfer system, an intermediate transfer member composed of a drum or a belt for temporarily transferring and holding the toner image on the photosensitive member is provided, and a magenta toner image, a yellow toner image, and a cyan toner are provided around the intermediate transfer member. An image and four photoconductors on which a black toner image is formed are arranged, and four color toner images are sequentially transferred onto the intermediate transfer member, thereby forming a color image on the intermediate transfer member. The 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 row as in the tandem method, so that the apparatus can be used. There is no particular increase in size, and there is no need to wrap the recording medium around the drum, so the type of recording medium is not limited.

  As an apparatus for forming a color image by the intermediate transfer method, an image forming apparatus using an endless belt-shaped intermediate transfer member as an intermediate transfer member is illustrated in FIG.

  In FIG. 3, reference numeral 11 denotes a drum-shaped photoconductor, which rotates in the direction of the arrow in the figure. The photosensitive member 11 is charged by the primary charger 12, and then the charged portion of the exposed portion is erased by image exposure 13, and an electrostatic latent image corresponding to the first color component is formed on the photosensitive member 11. The electrostatic latent image is developed with the first color magenta toner M by the developing device 41, and a first color magenta toner image is formed on the photoreceptor 11. Next, the toner image is circulated and driven by a driving roller (driving member) 30 and transferred to the intermediate transfer member 20 that circulates and rotates while contacting the photoreceptor 11. In this case, transfer from the photoconductor 11 to the intermediate transfer member 20 is performed by a primary transfer bias applied from the power source 61 to the intermediate transfer member 20 at the nip portion between the photoconductor 11 and the intermediate transfer member 20. After the first color magenta toner image is transferred to the intermediate transfer member 20, the surface of the photoconductor 11 is cleaned by the cleaning device 14, and the development transfer operation for the first rotation of the photoconductor 11 is completed. Thereafter, the photoconductor rotates three times, and the second color cyan toner image, the third color yellow toner image, and the fourth color black toner image are sequentially used by the developing units 42 to 44 for each turn. The toner image is formed on the intermediate transfer member 20 and is superimposed and transferred to the intermediate transfer member 20 every round, so that a composite color toner image corresponding to the target color image is formed on the intermediate transfer member 20. In the apparatus of FIG. 3, the developing devices 41 to 44 are sequentially replaced with each rotation of the photoreceptor 11 so that development with magenta toner M, cyan toner C, yellow toner Y, and black toner B is sequentially performed. It has become.

  Next, the 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 the paper feed cassette 19 to the nip portion. At the same time, a secondary transfer bias is applied from the power source 29 to the transfer roller 25, and the composite color toner image is transferred from the intermediate transfer member 20 onto the recording medium 26 and heated and fixed to form a final image. After the composite color toner image is transferred to the recording medium 26, the transfer residual toner on the surface is removed by the cleaning device 35, and the intermediate transfer member 20 returns to the initial state to prepare for the next image formation.

  There is also a tandem intermediate transfer method that combines a tandem method and an intermediate transfer method. FIG. 4 illustrates an image forming apparatus of a tandem intermediate transfer system that forms a color image using an endless belt-like tandem intermediate transfer member.

  In the illustrated apparatus, the first developing unit 54 a to the fourth developing unit 54 d that develop the electrostatic latent images on the photoconductive drums 52 a to 52 d with yellow, magenta, cyan, and black, respectively, along the tandem intermediate transfer member 50. The four-color toner images formed on the photosensitive drums 52a to 52d of the developing units 54a to 54d are sequentially driven by circulating the tandem intermediate transfer member 50 in the direction of the arrow in the drawing. By transferring, a color toner image is formed on the tandem intermediate transfer member 50, and the toner image is transferred onto a recording medium 53 such as paper to perform printout. Here, in any of the above-described apparatuses, the arrangement order of the toners used for development is not particularly limited, and can be arbitrarily selected.

  In the figure, reference numeral 55 denotes a driving roller or tension roller for circulatingly driving the tandem intermediate transfer member 50, reference numeral 56 denotes a recording medium feeding roller, reference numeral 57 denotes a recording medium feeding device, and reference numeral 58 denotes a recording medium. 3 shows a fixing device for fixing the image by heating or the like. Reference numeral 59 denotes a power supply device (voltage applying means) for applying a voltage to the tandem intermediate transfer member 50. The power supply device 59 transfers the toner image from the photosensitive drums 52a to 52d to the tandem intermediate transfer member 50. In this case, the polarity of the applied voltage can be reversed between the case where the image is transferred from the tandem intermediate transfer member 50 onto the recording medium 53.

Conventionally, as the conductive endless belt used as the endless belt-like transfer conveyance belt 10, the intermediate transfer member 20, the tandem intermediate transfer member 50, etc., a semiconductive resin film belt, a rubber belt having a fiber reinforcement, Is mainly used. Among these, as a resin film belt, for example, in Patent Document 1, an acrylonitrile-styrene (AS) resin containing a predetermined amount of a flexible component having a glass transition temperature Tg of less than 25 ° C., a polymer alloy of the AS resin and a thermoplastic resin, Alternatively, a conductive endless belt based on a polymer blend of the AS resin and a thermoplastic resin is disclosed. Patent Document 2 discloses thermoplastic polyamide (PA), acrylonitrile-butadiene-styrene (ABS) resin, thermoplastic polyacetal (POM), polymer alloy or polymer blend of any two or more of these, and these Disclosed is a conductive endless belt in which a polymer ion conductive agent is added to a substrate selected from the group consisting of a polymer alloy or a polymer blend of any one or more of these and a thermoplastic resin. Has been.
JP 2002-328541 A (Claims etc.) JP 2003-91177 A (Claims etc.)

  The required characteristics for the conductive endless belt applied to the image forming apparatus of the tandem method, intermediate transfer method, tandem intermediate transfer method, etc. are (1) high strength, (2) bending durability (bending resistance), (3 ) Good charging characteristics, (4) Glossiness, etc. Among these, the characteristics (1) to (3) can be achieved by the belt based on the ABS resin disclosed in Patent Document 1, but this ABS resin-based belt has (4) point of glossiness. And had a problem. The glossiness of the belt surface is important when the optical sensor controls the rotational position of the belt during driving.

  In order to increase the glossiness of the belt surface, it is effective to control the surface properties by transferring the mold surface when manufacturing the belt by a molding method using a mold. There is a problem of being extremely bad. Therefore, there has been a demand for a technique that can achieve both high glossiness and high productivity on the belt surface.

  Accordingly, an object of the present invention is to provide various required performances of the belt such as strength and charging characteristics, satisfy the required performance in terms of gloss, and have excellent productivity, and a conductive endless belt, and An object of the present invention is to provide an image forming apparatus using the same.

  As a result of intensive studies to solve the above-mentioned problems, the inventors have made the belt a laminated structure composed of a plurality of layers, ensuring each layer has different required performance, and forming the belt by coextrusion of these layers. Thus, the inventors have found that a belt having both high glossiness and high productivity can be realized without impairing other belt performance, and have completed the present invention.

In other words, the conductive endless belt of the present invention is configured to circulate and drive a recording medium held by electrostatic adsorption to four types of image forming bodies by a driving member, and sequentially transfer each toner image to the recording medium. For conductive endless belts for tandem transfer and transport,
It has a laminated structure including at least a base layer and an outermost layer sequentially from the inside, is formed by coextrusion, the base layer is mainly composed of acrylonitrile-butadiene-styrene (ABS) resin, and the outermost layer is polystyrene (PS) The main component is a resin or acrylonitrile-styrene (AS) resin.

Further, another conductive endless belt of the present invention is disposed between the image forming body and the recording medium, and is circulated and driven by a driving member to temporarily transfer the toner image formed on the surface of the image forming body. In the conductive endless belt for the intermediate transfer member that is transferred and held on the surface and transferred to the recording medium,
It has a laminated structure including at least a base layer and an outermost layer sequentially from the inside, is formed by coextrusion, the base layer has ABS resin as a main component, and the outermost layer has PS resin or AS resin as a main component. It is characterized by.

Furthermore, another conductive endless belt according to the present invention is disposed between the four types of image forming bodies and the recording medium, and is circulated by a driving member to be formed on the surface of the four types of image forming bodies. In the conductive endless belt for a tandem intermediate transfer member that sequentially transfers and holds the toner images to the surface of the toner, and transfers the toner images to a recording medium.
It has a laminated structure including at least a base layer and an outermost layer sequentially from the inside, is formed by coextrusion, the base layer has ABS resin as a main component, and the outermost layer has PS resin or AS resin as a main component. It is characterized by.

  The belt of the present invention preferably has a two-layer structure of the base layer and the outermost layer.

  The image forming apparatus of the present invention is characterized by using the conductive endless belt of the present invention.

  According to the present invention, the above configuration provides various required performances of the belt such as strength and charging characteristics, can satisfy the required performance in terms of gloss, and is excellent in productivity. It is possible to realize a conductive endless belt and an image forming apparatus using the same.

Hereinafter, preferred embodiments of the present invention will be described in detail.
In general, the conductive endless belt includes a jointed belt and a jointless belt (so-called seamless belt), but any one may be used in the present invention. A seamless belt is preferable. As described above, the conductive endless belt of the present invention can be used as a transfer member for 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 conveyance belt indicated by reference numeral 10 in FIG. 2, the toner is sequentially transferred onto a recording medium that is driven by a driving member such as a driving roller 9 and the like. As a result, a color image is formed.

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

  Furthermore, when the conductive endless belt of the present invention is, for example, a tandem intermediate transfer member denoted by reference numeral 50 in FIG. 4, the developing units 54a to 54d including the photosensitive drums 52a to 52d and the recording medium 53 such as paper are provided. The four-color toner images formed on the surfaces of the photosensitive drums 52 a to 52 d are temporarily transferred and held, and then transferred to the recording medium 53. To form a color image.

  FIG. 1 is a cross-sectional view in the width direction of a conductive endless belt according to a preferred embodiment of the present invention. As shown in the figure, the conductive endless belt 100 of the present invention has a laminated structure including at least a base layer 101 and an outermost layer 102 sequentially from the inside, the base layer 101 is mainly composed of ABS resin, and the outermost layer 102 is Mainly PS resin or AS resin. That is, the belt is multilayered and the base layer is made of ABS resin, and the outermost layer forming the belt surface is made of PS resin or AS resin having high gloss and good adhesion to the base layer ABS resin. By being used, desired belt characteristics are realized, and further, by being formed by coextrusion of these layers, the productivity is also excellent.

  As described above, the base layer 101 in the belt of the present invention forms the thickest layer of the laminated structure, and thus occupies at least 50%, preferably 60 to 99% of the total belt thickness. In the present invention, since the base layer is formed of ABS resin as a main component, a high-strength belt can be realized and excellent bending durability can be ensured.

  ABS resin is a thermoplastic resin excellent in impact resistance and dimensional stability, and can be easily obtained in the market. Specifically, for example, Techno ABS 430 manufactured by Techno Polymer Co., Ltd., Sebian V320 manufactured by Daicel Polymer Co., Ltd., and Sebian V680 can be used as representatives.

  On the other hand, the PS resin used for the outermost layer 102 of the belt of the present invention is a general-purpose thermoplastic resin and can be easily obtained on the market. For example, G320C manufactured by Toyo Styrene Co., Ltd. can be used. Moreover, AS resin is a thermoplastic resin excellent in impact resistance and dimensional stability, and can be easily obtained in the market. For example, Sanex SAN-C manufactured by Technopolymer Co., Ltd. can be used. Each of these resins has a characteristic that it is highly glossy and has excellent adhesion to the ABS resin.

  The belt of the present invention has a laminated structure including at least a base layer and an outermost layer, and preferably has a two-layer structure of a base layer and an outermost layer, but other base layer-outermost layer or another layer on the inner layer side of the base layer. Layers may be included. However, also in this case, it is necessary that the base layer forms the thickest layer in the laminated structure. As such another layer, for example, a layer having the same configuration as that of the outermost layer may be stacked.

  Moreover, in each layer which comprises the belt of this invention, in order to adjust electroconductivity, a conductive material is mix | blended. Such a conductive material is not particularly limited, and a known electronic conductive agent, ionic conductive agent, or the like can be appropriately used. Of these, specific examples of the electronic conductive agent include conductive carbon such as ketjen black and acetylene black, carbon for rubber such as SAF, ISAF, HAF, FEF, GPF, SRF, FT, and MT, oxidation treatment, and the like. Colored (ink) carbon, natural graphite, artificial graphite, antimony-doped tin oxide, titanium oxide, zinc oxide, nickel, copper, silver, germanium and other metal and metal oxides, polyaniline, Conductive polymers such as polypyrrole and polyacetylene, carbon whisker, graphite whisker, titanium carbide whisker, conductive potassium titanate whisker, conductive barium titanate whisker, conductive titanium oxide whisker, conductive zinc oxide whisker, etc. Is mentioned. Specific examples of the ion conductive agent include perchlorates such as tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, benzyltrimethylammonium, modified fatty acid dimethylethylammonium, chlorate, Ammonium salts such as hydrochloride, bromate, iodate, borofluoride, sulfate, ethyl sulfate, carboxylate, sulfonate, alkali metals such as lithium, sodium, potassium, calcium, magnesium And alkaline earth metal perchlorates, chlorates, hydrochlorides, bromates, iodates, borofluorides, sulfates, trifluoromethyl sulfates, sulfonates, and the like.

  As the conductive material, a polymer ion conductive agent can also be used. As such a polymeric ion conductive agent, for example, those described in JP-A-9-227717, JP-A-10-120924, and JP-A-2000-327922 can be used. It is not limited.

Specifically, mention may be made of a mixture comprising (A) an organic polymer material, (B) an ionically conductive polymer or copolymer, and (C) an inorganic or low molecular weight organic salt, wherein component (A) ) Is a polyacrylic ester, polymethacrylic ester, polyacrylonitrile, polyvinyl alcohol, polyvinyl acetate, polyamide, polyurethane or polyester, component (B) is an oligoethoxylated acrylate or methacrylate, oligoethoxylated for aromatic rings Styrene, polyether urethane, polyether urea, polyether amide, polyether ester amide or polyether ester, and component (C) is an alkali metal or alkaline earth metal of an inorganic or low molecular weight organic protonic acid , A lead or ammonium salt, _{preferably, LiClO 4, LiCF 3 SO 3} , NaClO 4, LiBF 4, NaBF 4, KBF 4, NaCF 3 SO 3, KClO 4, KPF 6, KCF 3 SO 3, KC 4 F 9 SO ₃ , Ca (ClO ₄ ) ₂ , Ca (PF ₆ ) ₂ , Mg (ClO ₄ ) ₂ , Mg (CF ₃ SO ₃ ) ₂ , Zn (ClO ₄ ) ₂ , Zn (PF ₆ ) ₂ or Ca (CF ₃ SO ₃ ) ₂ etc.

Among these, as the component (B), a polymer ionic conductive agent containing a polyether amide component or a polyether ester amide component is suitable, and in addition to this, a low molecular ionic conductive agent component as the component (C). It is preferable to contain. Further, as the polyether amide component and the polyether ester amide component, those in which the polyether component contains (CH ₂ —CH ₂ —O) and the polyamide component contains nylon 12 or nylon 6 are particularly preferable. As a component (B), a polymer ion conductive agent containing NaClO ₄ as a low molecular ion conductive agent component of component (C) is particularly suitable.

  Such polymer ion conductive agents include, for example, Irgastat (registered trademark) P18 and Irgastat (registered trademark) P22 (both manufactured by Ciba Specialty Chemicals, Inc.), Pelestat 230, 300 (manufactured by Sanyo Chemical Co., Ltd.), etc. As readily available in the market. When a polymer ion conductive agent is used as the conductive material, a compatibilizing agent may be added in order to increase the compatibility between the base resin and the polymer ion conductive agent.

  These conductive materials may be used singly or in appropriate combination of two or more. For example, an electronic conductive agent and an ionic conductive agent may be used in combination. Therefore, the conductivity can be stably expressed even with respect to fluctuations in voltage and environmental changes.

  The blending amount of the conductive material is usually 100 parts by weight or less, for example, 1 to 100 parts by weight, particularly 1 to 80 parts by weight, especially 5 to 50 parts per 100 parts by weight of the resin component for each layer and for the electronic conductor. Parts by weight. Moreover, about an ion conductive agent, it is 0.01-10 weight part normally with respect to 100 weight part of resin components, Especially 0.05-5 weight part is the range. Furthermore, about a polymeric ion electrically conductive agent, it is 1-500 weight part normally with respect to 100 weight part of resin components, Preferably it is about 10-400 weight part. In the present invention, it is particularly preferable to add 20 to 40 parts by weight of carbon black or a polymer ionic conductive agent as the conductive material with respect to 100 parts by weight of the resin component.

  Further, in the belt of the present invention, other functional components can be appropriately added in addition to the above-mentioned components within a range not impairing the effects of the present invention. For example, various fillers, coupling agents, Antioxidants, lubricants, surface treatment agents, pigments, ultraviolet absorbers, antistatic agents, dispersants, neutralizing agents, foaming agents, crosslinking agents, and the like can be appropriately blended. Furthermore, you may color by adding a coloring agent.

The total thickness of the conductive endless belt of the present invention is appropriately selected according to the form of the transfer / conveying belt or the intermediate transfer member, but is preferably in the range of 50 to 200 μm. The surface roughness is preferably 10 μm or less, particularly 6 μm or less, more preferably 3 μm or less in terms of JIS 10-point average roughness Rz. Furthermore, it is preferable to adjust the volume resistivity within a range of 10 ² Ω · cm to 10 ¹³ Ω · cm.

  Further, the conductive endless belt of the present invention has a surface on the side in contact with a driving member such as the driving roller 9 or the driving roller 30 of FIG. 3 in the image forming apparatus of FIG. 2, as shown by a one-dot chain line in FIG. A fitting portion that fits with a fitting portion (not shown) formed on the drive member may be formed, and the conductive endless belt of the present invention is provided with such a fitting portion and drives this. Shifting in the width direction of the conductive endless belt can be prevented by running with a fitting portion (not shown) provided on the member.

  In this case, the fitting portion is not particularly limited, but, as shown in FIG. 1, it is formed as a ridge continuous along the circumferential direction (rotation direction) of the belt, and this is a driving member such as a driving roller. It is preferable to be fitted in a groove formed in the circumferential surface along the circumferential direction.

  In addition, although the example which provided one continuous protruding item | line as a fitting part was shown in Fig.1 (a), this fitting part has many convex parts along the circumferential direction (rotation direction) of a belt. They may be arranged in a row, or two or more fitting portions may be provided (FIG. 1 (b)), or may be provided at the center in the width direction of the belt. Further, a groove along the circumferential direction (rotating direction) of the belt is provided as a fitting portion instead of the convex strip shown in FIG. 1, and this is formed along the circumferential direction on the circumferential surface of the driving member such as the driving roller. You may make it make it fit with the protruding item | line which carried out.

  Further, as the image forming apparatus of the present invention using the conductive endless belt of the present invention, the tandem system shown in FIG. 2, the intermediate transfer system shown in FIG. 3, or the tandem intermediate transfer system shown in FIG. Although the thing can be illustrated, it is not limited to these. In the case of the apparatus shown in FIG. 3, a voltage can be appropriately applied from the power source 61 to the drive roller 23 or the drive gear for rotating the intermediate transfer member 20 of the present invention. The application conditions, such as the application of weighting the alternating current, can be selected as appropriate.

  As described above, the conductive endless belt of the present invention is manufactured by co-extrusion of each layer constituting the laminated structure, and this makes it possible to achieve both desired high surface gloss and high productivity. It has become.

Hereinafter, the present invention will be described in more detail with reference to examples.
Examples 1-8 and Comparative Examples 1-6
Conductive endless belts of Examples and Comparative Examples were prepared with the formulations shown in Tables 1 and 2 below. Specifically, the blended components of each layer are melt-kneaded with a biaxial kneader, and the resulting kneaded product is co-extruded using a predetermined annular die to obtain an inner diameter of 220 mm and a total thickness of 100 μm (the thickness of each layer is A conductive endless belt having a width of 250 mm was obtained. The belts of the obtained examples and comparative examples were evaluated according to the following procedures. These results are also shown in Tables 1 and 2 below.

<Measurement of tensile modulus>
The tensile modulus was measured under the following conditions.
Apparatus: Manufactured by Shimadzu Corporation, tensile tester EZ test (analysis software: Trappezium)
Sample: strip shape (length 100 mm x width 10 mm x standard thickness 100 μm)
Tensile speed: 5mm / sec
Data sampling interval: 100 mmsec
Measurement method: Inclination measurement environment at 0.5-0.6% elongation: 23 ± 3 ° C., 50 ± 10% RH

<Measurement of volume resistance Rv>
At a temperature of 23 ° C. and a relative humidity of 50%, a sample chamber R12704A was connected to an ohmmeter R8340A manufactured by ADVANTEST, and the volume resistance Rv at a voltage of 500V was measured. The value of the volume resistance Rv is preferably about 1 × 10E6 to 1 × 10E13 [Ω · cm].

<Measurement of glossiness>
It measured using Gross Checker IG-320 by Horiba, Ltd. A gloss value of 45 or more is satisfactory without problems in use.

<Evaluation of image characteristics (image quality and contamination)>
Each belt was attached to a tandem type image forming apparatus using a transfer conveyance belt shown in FIG. 2, and a durability test was conducted on 100,000 sheets of A4 paper by repeating the transfer operation. The results of this test were evaluated for image quality and contamination. Regarding image quality, “◯” indicates that there is no color unevenness and no color loss due to foreign matter, and “x” indicates that there is color unevenness and color loss due to foreign matter. Contamination properties were evaluated as “◯” when the photoconductor was not contaminated or adhered, and “X” when the photoconductor was contaminated or adhered.

＊１：東洋スチレン（株）製、Ｇ３２０Ｃ
＊２：テクノポリマー（株）製、サンレックスＳＡＮ−Ｃ
＊３：電気化学工業（株）製、デンカブラック粒状
＊４：チバ・スペシャルティ・ケミカルズ・インコーポレイテッド（株）製、Ｉｒｇａｓｔａｔ Ｐ１８
＊５：テクノポリマー（株）製、テクノＡＢＳ４３０

* 1: Toyo Styrene Co., Ltd., G320C
* 2: Sanrex SAN-C manufactured by Techno Polymer Co., Ltd.
* 3: Denka Black granular, manufactured by Denki Kagaku Kogyo Co., Ltd. * 4: Irgastat P18, manufactured by Ciba Specialty Chemicals, Inc.
* 5: Techno ABS Co., Ltd., Techno ABS430

  As shown in Tables 1 and 2 above, the belt of each example using ABS resin for the base layer of the laminated structure and PS resin or AS resin for the outermost layer, while ensuring the tensile elastic modulus, charging characteristics, etc. It was confirmed that the required performance can be satisfied in terms of glossiness. On the other hand, the belts of the comparative examples having a single-layer structure with only the base layer using ABS resin satisfy belt characteristics such as tensile elastic modulus, but have insufficient glossiness and are problematic in terms of practicality. It was what had.

It is width direction sectional drawing of the electroconductive endless belt which concerns on one embodiment of this invention. 1 is a schematic diagram illustrating a tandem type image forming apparatus using a transfer conveyance belt as an example of an image forming apparatus of the present invention. FIG. 6 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. FIG. 6 is a schematic view showing a tandem intermediate transfer device using a tandem intermediate transfer member as another example of the image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 11, 52a-52d Photosensitive drum 2, 7 Charging roll 3 Developing roll 4 Developing blade 5 Toner supply roll 6 Cleaning blade 8 Static elimination roll 9, 30, 55 Driving roller (driving member)
DESCRIPTION OF SYMBOLS 10 Transfer conveyance belt 12 Primary charger 13 Image exposure 14, 35 Cleaning device 19 Paper feed cassette 20 Intermediate transfer member 25 Transfer roller 26, 53 Recording medium 29, 61 Power supply 41, 42, 43, 44 Developer 50 Tandem intermediate transfer member 54a to 54d First developing portion to fourth developing portion 56 Recording medium feeding roller 57 Recording medium feeding device 58 Fixing device 59 Power supply device (voltage applying means)
100 conductive endless belt 101 base layer 102 outermost layer

Claims (5)

Conductive endless belt for tandem transfer and conveyance, in which a recording medium held by electrostatic adsorption is circulated and driven by a driving member, conveyed to four types of image forming bodies, and each toner image is sequentially transferred to the recording medium. In
It has a laminated structure including at least a base layer and an outermost layer sequentially from the inside, is formed by coextrusion, the base layer is mainly composed of acrylonitrile-butadiene-styrene resin, and the outermost layer is polystyrene resin or acrylonitrile-styrene resin. Conductive endless belt characterized by comprising a main component. The toner image formed between the image forming body and the recording medium is circulated and driven by a driving member, and the toner image formed on the surface of the image forming body is once transferred and held on the surface of the image forming body and transferred to the recording medium. In the conductive endless belt for the intermediate transfer member
It has a laminated structure including at least a base layer and an outermost layer sequentially from the inside, is formed by coextrusion, the base layer is mainly composed of acrylonitrile-butadiene-styrene resin, and the outermost layer is polystyrene resin or acrylonitrile-styrene resin. Conductive endless belt characterized by comprising a main component. Arranged between the four types of image forming bodies and the recording medium, and circulated and driven by a driving member, and sequentially transferring and holding the toner images formed on the surfaces of the four types of image forming bodies on the surface of the recording medium. In a conductive endless belt for a tandem intermediate transfer member that transfers this to a recording medium,
It has a laminated structure including at least a base layer and an outermost layer sequentially from the inside, is formed by coextrusion, the base layer is mainly composed of acrylonitrile-butadiene-styrene resin, and the outermost layer is polystyrene resin or acrylonitrile-styrene resin. Conductive endless belt characterized by comprising a main component.   The conductive endless belt according to any one of claims 1 to 3, which has a two-layer structure of the base layer and the outermost layer.   An image forming apparatus using the conductive endless belt according to claim 1.

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