JP2007065587A - Conductive endless belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-performance conductive endless belt having excellent surface property and durability almost equal to a conventional thermosetting resin belt or a rubber layered belt while avoiding problems about the cost. <P>SOLUTION: The conductive endless belt is produced by extrusion molding a crosslinking resin composition prepared by compounding a conducting agent and a crosslinking agent into a polyester-based resin or a polymer blend essentially comprising a polyester-based resin, then by crosslinking by electron beam irradiation. A polyalkylene naphthalate resin or a polyalkylene terephthalate resin can be preferably used for the polyester-based 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 the toner image formed in this way onto a recording medium such as paper.

  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.

As the conductive endless belt used as the transfer conveyance belt 10, the intermediate transfer member 20, the tandem intermediate transfer member 50, etc. in the various image forming apparatuses described above, conventionally, a semiconductive resin film belt and a fiber reinforcement have been provided. Rubber belts are mainly used. Among these, as the resin film belt, for example, Patent Document 1 discloses a conductive endless belt using a thermoplastic polyalkylene naphthalate resin, or a polymer alloy or a polymer blend of the thermoplastic polyalkylene naphthalate resin and another thermoplastic resin as a base material. Are listed. In addition, as belts having excellent durability, laminated belts based on crosslinked rubber, belts obtained by rotational molding of thermosetting resins such as polyimide, and the like are known. A technique for producing a belt by extruding a thermoplastic resin is also known. Further, Patent Documents 2, 3 and the like describe techniques related to a belt using a crosslinkable resin.
JP 2002-132053 A (Claims etc.) JP-A-10-147720 (Claims etc.) JP 2000-264477 A (Claims etc.)

  The conductive endless belts used in the various image forming apparatuses are required to have various characteristics according to the use environment in a well-balanced manner, such as excellent surface properties and good durability. . However, although conventional thermosetting resin belts and rubber laminated belts are excellent in terms of performance, they have the disadvantage that they are very expensive, and thermoplastic resin extruded belts are low in cost but are thermosetting resin. Compared to belts and the like, there are problems in that they are inferior in characteristics such as folding resistance and set resistance, and none of them is sufficient.

  Therefore, an object of the present invention is to provide a high-performance conductive endless belt that is free from cost problems like conventional thermosetting resin belts and rubber laminated belts, and has excellent surface properties and durability equivalent to these. Is to provide.

  As a result of intensive studies, the present inventors have found that the above-described problems can be solved by adopting the following configuration, 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,
A crosslinkable resin composition in which a conductive agent and a crosslinking agent are blended with a polyester resin or a polymer blend containing a polyester resin as a main component is subjected to a crosslinking treatment by electron beam irradiation after extrusion molding. To do.

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,
A crosslinkable resin composition in which a conductive agent and a crosslinking agent are blended with a polyester resin or a polymer blend containing a polyester resin as a main component is subjected to a crosslinking treatment by electron beam irradiation after extrusion molding. To do.

Further, 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.
A crosslinkable resin composition in which a conductive agent and a crosslinking agent are blended with a polyester resin or a polymer blend containing a polyester resin as a main component is subjected to a crosslinking treatment by electron beam irradiation after extrusion molding. To do.

  In the present invention, a polyalkylene naphthalate resin or a polyalkylene terephthalate resin can be suitably used as the polyester resin. Moreover, as said crosslinking agent, an allylic polyfunctional monomer is suitable and it can mix | blend in 0.5-15 weight part with respect to 100 weight part of resin components. Examples of such allyl polyfunctional monomers include triallyl isocyanurate, triallyl cyanurate, trimethallyl isocyanurate, diallyl monoglycidyl isocyanurate, and the like.

  Further, carbon black is suitable as the conductive agent, and it can be blended at 5 to 30 parts by weight with respect to 100 parts by weight of the resin component. Furthermore, in the present invention, it is preferable that the crosslinkable resin composition contains a carbodiimide compound.

  According to the present invention, a crosslinkable resin composition obtained by blending a polyester resin or a polymer blend containing the same as a main component with a conductive agent and a crosslinking agent is extruded into a belt shape and then irradiated with an electron beam. By using a three-dimensionally cross-linked belt, there is no cost problem like conventional thermosetting resin belts and rubber laminated belts, and high performance with excellent surface properties and durability equivalent to these. It has become possible to realize a conductive endless belt.

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.

  In the conductive endless belt of the present invention, a crosslinkable resin composition comprising a polyester resin or a polymer blend containing a polyester resin as a main component and a conductive agent and a crosslinker are blended by electron beam irradiation after extrusion molding. It is characterized in that it is crosslinked.

  Specific examples of the polyester-based resin used in the present invention include polyalkylene naphthalate resin and polyalkylene terephthalate resin. Among these, polyalkylene naphthalate resin is preferably polyethylene naphthalate (PEN). Resin, polybutylene naphthalate (PBN) resin, or the like can be preferably used. These resins are commercially available. For example, TN8065S manufactured by Teijin Chemicals Ltd. can be used as the PEN resin, and TQB-OT manufactured by Teijin Chemicals Co., Ltd. can be used as the PBN resin.

  As the polyalkylene terephthalate resin, polyethylene terephthalate (PET) resin, glycol-modified PET (PETG) resin or polybutylene terephthalate (PBT) resin can be suitably used. These resins are also readily available in the market. For example, KC-251 manufactured by Mitsubishi Rayon Co., Ltd. can be used as the PET resin, and 800FP manufactured by Polyplastics Co., Ltd. can be used as the PBT resin. it can.

  Moreover, as a polymer blend which has a polyester-type resin as a main component, any 2 or more types of polymer blend among the said polyalkylene naphthalate resin and a polyalkylene terephthalate resin, and any one or more of these and a polyester type An elastomer, a polycarbonate resin (PC), a polycyclohexylene / dimethylene / terephthalate (PCT) resin, a polymer blend with a glycol-modified PCT (PCTG) resin, or the like can be preferably used. As such a polyester-based elastomer, both a polyester-polyester type using a polyester for the hard segment and the soft segment and a polyester-polyether type using a polyether for the hard segment and the soft segment are preferably used. There is no particular limitation. In the present invention, “mainly comprising” means containing 50% by weight or more of a polyester resin as a resin component.

  The cross-linking agent is not particularly limited as long as it can cause a cross-linking reaction by irradiation with an electron beam, but an allylic polyfunctional monomer is preferably used. Specific examples of such allylic polyfunctional monomers include triallyl isocyanurate, triallyl cyanurate, trimethallyl isocyanurate, diallyl monoglycidyl isocyanurate (DA-MGIC), and DA-MGIC among others. Is suitable because a crosslinking effect is manifested in a small amount. Other cross-linking agents include polyfunctional (meth) acrylic monomers such as diethylene glycol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, pentaerythritol tri ( (Meth) acrylate, pentaerythritol tetra (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, tris (methacryloxyethyl) isocyanurate and mixtures thereof Can also be used. These may be used singly or as a mixture of any two or more thereof as desired. The preferred blending amount is 0.5 to 15 weights with respect to 100 parts by weight of the resin component. Part, in particular, about 2 to 10 parts by weight. If the amount is too large, it is not preferable because it leads to poor appearance and reduced strength.

  The conductive agent 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.

  These conductive agents 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. Conductivity can be expressed stably even with respect to voltage fluctuations and environmental changes.

  The compounding amount of the electronic conductive agent is usually 100 parts by weight or less, for example, 1 to 100 parts by weight, particularly 1 to 80 parts by weight, especially 10 to 50 parts by weight with respect to 100 parts by weight of the resin component. Moreover, the compounding quantity of an ionic conductive agent is 0.01-10 weight part normally with respect to 100 weight part of resin components, Especially the range of 0.05-5 weight part. In the present invention, it is particularly preferable to use carbon black as a conductive agent and mix it with 5 to 30 parts by weight with respect to 100 parts by weight of the resin component.

  In addition, since the polyester-based resin used in the present invention is likely to cause a decrease in molecular weight due to hydrolysis during molding and heating, the crosslinkable resin composition according to the present invention may contain a carbodiimide compound in addition to the above components. preferable. By compounding a carbodiimide compound, the polyester resin can be re-crosslinked by the reaction between the carbodiimide group and the carboxylic acid to prevent a decrease in molecular weight and to prevent the belt from becoming brittle. It becomes possible to improve the property. Such carbodiimide compounds are easily available on the market, and examples thereof include trade name: Carbodilite manufactured by Nisshinbo Industries, Inc. The carbodiimide compound can also be used in the form of a masterbatch pellet or the like, for example, Nisshinbo Co., Ltd. trade name: Carbodilite E pellet can be suitably used.

  The amount of the carbodiimide compound added is not particularly limited, but is preferably 0.05 to 30 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the resin component. Is within.

  In addition, other functional components can be appropriately added to the conductive endless belt of the present invention as long as the effects of the present invention are not impaired. For example, various fillers, coupling agents, antioxidants, A lubricant, a surface treatment agent, a pigment, an ultraviolet absorber, an antistatic agent, a dispersant, a neutralizing agent, a foaming agent, a crosslinking agent, and the like can be appropriately blended. Furthermore, you may color by adding a coloring agent.

  The belt of the present invention is formed by three-dimensionally crosslinking by irradiating an electron beam after kneading the crosslinkable resin composition containing the above various components and extruding it into a cylindrical shape. The Extrusion molding may be performed according to a conventional method, and is not particularly limited. In addition, when irradiating an electron beam, for example, a method of inserting a metal cylinder into an extruded belt and irradiating while rotating the cylinder can be used. It is possible to uniformly irradiate the entire belt with an electron beam while preventing distortion and bending of the belt. There is no particular limitation on the electron beam irradiation apparatus to be used, and a commercially available apparatus can be used as appropriate, and the irradiation amount may be appropriately determined depending on the thickness of the belt or the composition of the crosslinkable resin composition, There is no particular limitation. In addition, the electron beam may be irradiated all at once, but when the belt is deformed due to the heat generated during irradiation, it is desirable to irradiate it in a plurality of times.

  The belt of the present invention is not particularly limited as long as it is subjected to crosslinking treatment by electron beam irradiation after extrusion molding using the crosslinkable resin composition. The layer structure may be either a single layer or multiple layers, and in the case of multiple layers, electron beam irradiation may be appropriately performed after molding using a multilayer extrusion technique.

The 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. The belt can be prevented from shifting in the width direction by being fitted with a fitting portion (not shown) provided on the member and running.

  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.

Hereinafter, the present invention will be described in more detail with reference to examples.
Examples 1-9 and Comparative Examples 1-8
Each compounding component shown in each of the following Tables 1 to 4 (all the compounding amounts in the table indicate “parts by weight”) is melt-kneaded with a biaxial kneader, and the resulting kneaded product is used using an annular die. By extrusion molding, a cylindrical belt having an inner diameter of 220 mm, a thickness of 100 μm, and a width of 250 mm was obtained. Thereafter, a metal cylindrical body was inserted into the belt, and the surface of the belt was irradiated with an electron beam while rotating the cylindrical body to obtain conductive endless belts of the examples and comparative examples (Comparative Examples 1 and 2). No electron beam irradiation was conducted for 3, 5-7). The electron beam was irradiated with 5 Mrad six times using an electron beam irradiation apparatus manufactured by NHV Corporation, and the total amount was constant at 30 Mrad.
Each belt obtained was evaluated according to the following procedure.

<Folding resistance>
The number of bending resistances was measured using an MIT fatigue resistance tester manufactured by Toyo Seiki Co., Ltd., and the results were shown as an index, with Comparative Example 1 taken as 100. The higher the number, the better the result.

<Set resistance>
In an environment with a temperature of 30 ° C and a relative humidity of 85%, the belt is left for 24 hours with 2 kg stretched on each belt, and then evaluated based on the running performance when it is mounted on an actual machine and run. It was. When the running property did not change, “◯” was indicated, when the severe meandering or idling occurred, “×”, and when there was a slight change in running property, “△” was indicated.

<Glossiness>
Measurement was performed using a handy gloss meter IG-320 manufactured by Horiba.
Each above evaluation result is shown in the following Tables 1-4.

＊１）ＰＢＮ：帝人化成（株）製、商品名 ＴＱＢ−ＯＴ
＊２）ＰＥＮ：帝人化成（株）製、商品名 ＴＮ８０６５Ｓ
＊３）ＰＥＴ：三菱レイヨン（株）製、商品名 ＫＣ−２５１
＊４）ＰＢＴ：ポリプラスチックス（株）製、商品名 ８００ＦＰ
＊５）エラストマー：帝人化成（株）製、商品名 ヌーベラン Ｐ４１１０ＡＮ
＊６）カーボンブラック：電気化学工業（株）製、商品名 デンカブラック
＊７）架橋剤（タイク）：日本化成（株）製、トリアリルイソシアヌレート
＊８）架橋剤（ＤＡ−ＭＧＩＣ）：四国化成工業（株）製 ジアリルモノグリシジルイソシアヌレート
＊９）カルボジイミド化合物：日清紡績（株）製、商品名「カルボジライトＥペレット」

* 1) PBN: manufactured by Teijin Chemicals Ltd., trade name: TQB-OT
* 2) PEN: manufactured by Teijin Chemicals Ltd., trade name: TN8065S
* 3) PET: Mitsubishi Rayon Co., Ltd., trade name KC-251
* 4) PBT: Polyplastics Co., Ltd., trade name: 800FP
* 5) Elastomer: Teijin Kasei Co., Ltd., trade name: Nouvelan P4110AN
* 6) Carbon black: manufactured by Denki Kagaku Kogyo Co., Ltd., trade name DENKA BLACK * 7) Crosslinker (Tyke): Nippon Kasei Co., Ltd., triallyl isocyanurate * 8) Crosslinker (DA-MGIC): Shikoku Diallyl monoglycidyl isocyanurate * 9) Carbodiimide compound: Nisshinbo Co., Ltd., trade name "Carbodilite E pellet"

  As is clear from the results of Tables 1 to 4 above, in the belts of the examples using the crosslinkable resin composition containing an allyl polyfunctional monomer as a crosslinker, the fold resistance was maintained without impairing the appearance. Good results have been obtained for the number of times and set resistance. In particular, it was confirmed that the PBN-based belts of Examples 1 to 6 have good glossiness and can be suitably used for transfer belts for electrophotography. Moreover, as a crosslinking agent, it turned out that an allyl type polyfunctional monomer, especially DA-MGIC especially is suitable because a crosslinking effect expresses in a small amount.

It is width direction sectional drawing of the electroconductive endless belt which concerns on one embodiment of this invention. FIG. 2 is a schematic diagram illustrating a tandem image forming apparatus using a transfer conveyance belt as an example of an image forming apparatus. FIG. 6 is a schematic diagram illustrating an intermediate transfer device using an intermediate transfer member as another example of an image forming apparatus. FIG. 5 is a schematic diagram illustrating a tandem intermediate transfer device using a tandem intermediate transfer member as another example of an image forming apparatus.

Explanation of symbols

1, 11, 52a to 52d Photosensitive drums 2, 7 Charging roll 3, Developing roll 4, Developing blade 5, Toner supply roll 6, Cleaning blade 8, Static eliminating 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)

Claims (9)

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
A crosslinkable resin composition in which a conductive agent and a crosslinking agent are blended with a polyester resin or a polymer blend containing a polyester resin as a main component is subjected to a crosslinking treatment by electron beam irradiation after extrusion molding. Conductive endless belt. 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
A crosslinkable resin composition in which a conductive agent and a crosslinking agent are blended with a polyester resin or a polymer blend containing a polyester resin as a main component is subjected to a crosslinking treatment by electron beam irradiation after extrusion molding. Conductive endless belt. 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,
A crosslinkable resin composition in which a conductive agent and a crosslinking agent are blended with a polyester resin or a polymer blend containing a polyester resin as a main component is subjected to a crosslinking treatment by electron beam irradiation after extrusion molding. Conductive endless belt.   The conductive endless belt according to any one of claims 1 to 3, wherein the polyester resin is a polyalkylene naphthalate resin.   The conductive endless belt according to any one of claims 1 to 3, wherein the polyester resin is a polyalkylene terephthalate resin.   The conductive endless belt according to any one of claims 1 to 5, wherein the crosslinking agent is an allylic polyfunctional monomer and is blended in an amount of 0.5 to 15 parts by weight with respect to 100 parts by weight of the resin component.   The allyl polyfunctional monomer is selected from the group consisting of triallyl isocyanurate, triallyl cyanurate, trimethallyl isocyanurate, diallyl monoglycidyl isocyanurate and a mixture of any two or more thereof. The conductive endless belt described.   The conductive endless belt according to any one of claims 1 to 7, wherein the conductive agent is carbon black and is blended at 5 to 30 parts by weight with respect to 100 parts by weight of the resin component.   The conductive endless belt according to claim 1, wherein the crosslinkable resin composition contains a carbodiimide compound.

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