JPWO2005000964A1 - Conductive endless belt and image forming apparatus using the same - Google Patents

Abstract

Provided is a high-performance conductive endless belt having good strength, particularly good bending durability, and excellent in creep resistance, dimensional stability, heat resistance, and the like, and an image forming apparatus using the same. . The base material is a polyphenylene sulfide (PPS) resin, a polymer alloy of a PPS resin and another thermoplastic resin, or a polymer blend of a PPS resin and another thermoplastic resin. This is an image forming apparatus using this belt. As the thermoplastic resin, those selected from the group consisting of polyphenylene ether resin, polyalkylene naphthalate resin, polyamide resin, polyarylate resin, polyimide resin, and liquid crystal polymer are suitable. Those selected from the group consisting of elastomers, olefin elastomers, and styrene elastomers can also be suitably used.

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 drawback 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.

  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 endless belt-like conductive endless belt such as the intermediate transfer member 20, a semiconductive resin film belt and a rubber belt having a fiber reinforcement are mainly used. Among these, as semiconductive resin film belts, those obtained by blending carbon black with polycarbonate have been known, but recently, polyalkylene terephthalate has been improved based on the durability in terms of bending. A resin film belt used as a material, a resin film belt based on a thermoplastic polyimide whose elastic surface is improved, and the like have been proposed. The applicant has also proposed various conductive endless belts using a specific resin material for the base material in Patent Document 1, Patent Document 2, and the like.
JP 2002-132053 A JP 2003-91177 A

  In tandem, intermediate transfer, and tandem intermediate transfer image forming apparatuses that use conductive endless belts, it is required that the conductive endless belt has sufficient strength to withstand repeated use in terms of mechanism. . Specifically, it is necessary to improve the insufficient strength represented by the occurrence of cracks due to end faces, scratches, etc., particularly the insufficient bending durability. In addition to improving creep resistance and dimensional stability that affect image accuracy, it is also required to realize excellent heat resistance that can cope with the increase in the temperature environment in equipment accompanying the recent increase in speed and compactness. It is coming. In addition, stretchability, impact resistance, and the like are important characteristics of the belt.

  As described above, various types of conductive resin film belts have been proposed, and some have been put into practical use so far. However, as the performance of image forming apparatuses increases, there is a need today that satisfies the above required characteristics better.

  Accordingly, an object of the present invention is to provide a resin film belt used in an image forming apparatus of a tandem method, an intermediate transfer method, and a tandem intermediate transfer method, which has a good strength, particularly a good bending durability, and has a creep resistance and It is an object to provide a high-performance conductive endless belt excellent in dimensional stability and heat resistance, and an image forming apparatus using the same.

  As a result of intensive studies on various synthetic resins to solve the above problems, the present inventors have used the above object by using a polyphenylene sulfide (PPS) resin or a polymer alloy or a polymer blend thereof as a base material for a conductive endless belt. The present invention has been completed.

  That is, the conductive endless belt of the present invention is based on polyphenylene sulfide resin, polymer alloy of polyphenylene sulfide resin and other thermoplastic resin, or polymer blend of polyphenylene sulfide resin and other thermoplastic resin. It is characterized by.

  As the thermoplastic resin, a resin selected from the group consisting of a polyphenylene ether resin, a polyalkylene naphthalate resin, a polyamide resin, a polyarylate resin, a polyimide resin, and a liquid crystal polymer can be suitably used. Moreover, a thermoplastic elastomer can also be used suitably as said thermoplastic resin, As this thermoplastic elastomer, what is selected from the group which consists of a polyester-type elastomer, an olefin-type elastomer, and a styrene-type elastomer is suitable.

  Moreover, it is also preferable that the conductive material is added as a functional component to the belt of the present invention, and in particular, carbon black as the conductive material is added in an amount of 0.1 to 100 with respect to 100 parts by weight of the resin component. It is preferable to add parts by weight.

Further, the belt of the present invention preferably has a volume resistance of 10 ⁰ to 10 ¹³ Ω · cm. Furthermore, it is preferable that a reinforcing material is added to the belt of the present invention. As the reinforcing material, an inorganic compound having an aspect ratio of 5 or more is suitable.

  Furthermore, it is preferable that the belt of the present invention has a fitting portion that fits with the driving member on a surface that comes into contact with the driving member, and the fitting portion is preferably along the rotation direction. It is a ridge that protrudes continuously.

  The belt of the present invention is a tandem type transfer in which a recording medium held by electrostatic attraction 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. The toner image formed on the surface of the image forming body can be suitably used as a conductive endless belt for conveyance, and is disposed between the image forming body and a recording medium and is circulated and driven by a driving member. For the intermediate transfer member that is once transferred and held on its surface and transferred to the recording medium, and disposed between the four types of image forming bodies and the recording medium, and is circulated and driven by a driving member. The toner images formed on the surfaces of the four types of image forming bodies can be suitably used also for a tandem intermediate transfer member that sequentially transfers and holds the toner images on the surface of the image once and transfers them to a recording medium.

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

  The conductive endless belt of the present invention described above has high strength, particularly excellent bending durability, and is excellent in creep resistance, dimensional stability, and heat resistance by using PPS resin as a base material. Also has good performance. In addition, when a fitting portion that fits the drive member and the conductive endless belt is provided, the phenomenon that the conductive endless belt stretched around two or more shafts is displaced in the width direction as it rotates is prevented. can do. Further, according to the image forming apparatus of the present invention, it is possible to provide a good image without causing a defect even when used for a long period of time.

  As described above, according to the present invention, a high-performance conductive endless belt having good strength, particularly good bending durability, and excellent in creep resistance, dimensional stability, and heat resistance. Can be provided. Further, by appropriately selecting the thermoplastic resin used as the base resin together with the PPS resin, it is possible to further improve the properties such as strength, elongation, elastic modulus, impact resistance, and durability. Therefore, according to the image forming apparatus of the present invention using the conductive endless belt of the present invention, a good image can be obtained without a defect even after long-term use.

Hereinafter, embodiments of the present invention will be described.
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. Are transferred to form a color image.

  The polyphenylene sulfide (PPS) resin used for the conductive endless belt of the present invention is a crystalline thermoplastic resin, and has extremely high heat resistance compared to general-purpose engineering plastics, and has chemical resistance, mechanical strength, and electrical characteristics. In addition, it has the feature of being excellent in cost. PPS resin is available on the market. For example, the product name DIC PPS manufactured by Dainippon Ink & Chemicals, Inc., the product name Asahi PPS manufactured by Asahi Glass Co., Ltd., the product name Sastil manufactured by Tosoh Corporation, and Mitsubishi. A typical example is Novaps, a product name manufactured by Engineering Plastics Co., Ltd. In the present invention, by using such a PPS resin as the base material of the conductive endless belt, there is obtained a belt that is free from variations in resistance, has excellent strength, particularly bending durability, and can prevent cracking well. be able to. In addition, since the creep resistance and heat resistance can be improved and high dimensional accuracy can be realized, it is possible to contribute to the improvement of image accuracy, and it is possible to cope with high speed and compactness.

  In the present invention, a polymer alloy or a polymer blend of a PPS resin and a thermoplastic resin, particularly a thermoplastic elastomer, may be used in accordance with desired belt characteristics. A belt having the required characteristics can be obtained. Examples of the thermoplastic resin include polyalkylene terephthalate resin, polyamide (PA) resin, polyacetal resin, polyalkylene naphthalate resin, liquid crystal polymer, acrylonitrile-butadiene-styrene (ABS) resin, fluorine resin, and polycarbonate (PC) resin. , Polyphenylene ether resin, polyarylate resin, and polyimide (PI) resin. Preferred are polyphenylene ether resin, polyalkylene naphthalate resin, PA resin, polyarylate resin, PI resin and liquid crystal polymer. Examples of thermoplastic elastomers include polyester elastomers, olefin elastomers, and styrene elastomers. As other thermoplastic resins, those having a melting point close to that of the PPS resin are practically preferable.

  The preferred addition amount in the case of using other thermoplastic resins added to the PPS resin depends on the type of the resin to be added, but for example, other thermoplastic resins 1 to 50 with respect to 100 parts by weight of the PPS resin. The amount can be about 5 to 40 parts by weight, particularly about 5 to 40 parts by weight. If the amount of other thermoplastic resin added is too large, there is a risk that adverse effects such as deterioration of workability, deterioration of surface properties, embrittlement, and high cost may occur. On the other hand, if the amount is too small, the performance equivalent to that of the PPS resin alone can be obtained, but the effect of improving the properties by the addition of other thermoplastic resins is insufficient. The amount of the thermoplastic elastomer added is preferably about 1 to 10 parts by weight, particularly about 1 to 5 parts by weight with respect to 100 parts by weight of the PPS resin.

In addition, a conductive material can be added or adjusted as a functional component to a PPS resin or a polymer alloy or polymer blend of a PPS resin, which is a base material of a conductive endless belt, and a thermoplastic resin. . In this case, the conductive material is not particularly limited. Lauryltrimethylammonium, stearyltrimethylammonium, octadecyltrimethylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, modified fatty acid / dimethylethylammonium perchlorate, chlorate , Cationic surfactants such as quaternary ammonium such as borofluoride, sulfate, ethosulphate salt, benzyl halide salt (benzyl bromide salt, benzyl chloride salt, etc.); aliphatic sulfonic acid, higher alcohol Anionic surfactants such as sulfate ester salts, higher alcohol ethylene oxide addition sulfate salts, higher alcohol phosphate ester salts; amphoteric surfactants such as various betaines; higher alcohol ethylene oxides, polyethylene glycols Fatty acid esters, polyhydric alcohol fatty acid ester antistatic agent such as a nonionic antistatic agents such _{as, LiCF 2 SO 2, NaClO 4} , LiBF 4, periodic table Group 1 metal salts such as NaCl; Ca (ClO ₄ ) Metal salts belonging to Group 2 of the periodic table such as ₂ : and these antistatic agents have one or more groups (hydrogen groups, carboxyl groups, primary to secondary amine groups, etc.) having active hydrogen that reacts with isocyanate. Things. Furthermore, ions of these and complexes 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; carbon for rubber such as SAF, ISAF, HAF, FEF, GPF, SRF, FT, MT; carbon for oxidized color ink, pyrolytic carbon, Examples thereof include natural graphite, artificial graphite and the like; metals and metal oxides such as tin oxide, titanium oxide, zinc oxide, nickel and copper; and conductive polymers such as polyaniline, polypyrrole and polyacetylene.

When the conductive material is carbon black, the amount of these conductive materials added to the base is 0.1 to 100 parts by weight, preferably 1 to 50 parts by weight, based on 100 parts by weight of the resin component. it can. As a result, the volume resistance of the conductive endless belt can be adjusted to 10 ⁰ to 10 ¹³ Ω · cm, preferably 10 ⁵ to 10 ¹² Ω · cm.

  Further, in the present invention, other functional components can be added in addition to the above-mentioned components within the range not impairing the effects of the present invention. For example, various fillers, molding modifiers, coupling agents, oxidation agents An inhibitor, 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, a compatibilizing material, a colorant, and the like can be appropriately blended. In particular, it is preferable to add a reinforcing material to improve mechanical properties such as strength, elastic modulus and impact strength. As such a reinforcing material, an inorganic compound having an aspect ratio of 5 or more, for example, calcium silicate, potassium titanate, magnesium sulfate, or the like can be suitably used.

  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.

  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.

  The conductive endless belt of the present invention is not particularly limited, but 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.

  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 applied from an appropriate power source 61 to the driving roller or driving 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.

  Further, the method for producing the conductive endless belt of the present invention is not particularly limited. For example, the resin component (PPS resin or a polymer alloy or polymer blend of this and a thermoplastic resin) and the conductive property are processed by a biaxial kneader. It can be manufactured by kneading functional components such as materials and extruding the obtained kneaded product using an annular die. Alternatively, a powder coating method such as electrostatic coating, a dip method, or a centrifugal casting method can be suitably employed.

The present invention will be described below based on examples.
Example 1
100 parts by weight of PPS resin (Dainippon Ink Chemical Co., Ltd., trade name: LD-10) and 20 parts by weight of electrified black (manufactured by Denki Kagaku Kogyo Co., Ltd.) are melt-kneaded with a twin-screw kneader The obtained kneaded product was extruded to obtain a conductive endless belt having an inner diameter of 245 mm, a thickness of 0.1 mm, and a width of 250 mm. The number of bending resistances of the conductive endless belt was measured using a toughness fatigue tester manufactured by Toyo Seiki Co., Ltd. Further, the tensile creep amount was measured at a temperature of 25 ° C. for 1200 hours in accordance with the JIS K7115 test method. Further, the volume resistance is measured at a temperature of 20 ° C. and a relative humidity of 50% using a measuring voltage of 100 V and a measuring device manufactured by ADVANTEST as a resistance meter R8340A connected to a sample chamber R12704A. It was.

Comparative Example 1
30 parts by weight of FEF carbon (Asahi Carbon Co., Ltd.) is blended with 100 parts by weight of thermoplastic polycarbonate resin (Teijin Kasei Co., Ltd., trade name: Panlite K1300Y) and melt-kneaded with a biaxial kneader. Except for the above, a conductive endless belt was produced in the same manner as in Example 1 and measured in the same manner as in Example 1.

Further, each belt of the above examples and comparative examples was mounted on a tandem type image forming apparatus using the transfer conveyance belt shown in FIG. 2, and the transfer operation was repeated to test the durability of 100,000 A4 sheets. The results of this test were evaluated for image quality.
The results of the above bending resistance test, tensile creep amount measurement and volume resistance measurement, and the results of the durability test are shown together in Table 1 below. In addition, about the result of the bending-proof test in the table | surface, Example 1 was set to 100 or more, and it represented by the index | exponent as the frequency | count of folding-proof. The higher the number, the better the result.

  From the results of the above measurements and tests, it was confirmed that the conductive endless belts of the examples had significant advantages in terms of bending durability and creep resistance. Also, good results were obtained for image quality. That is, it has been confirmed that when PPS resin is used alone as a base material for a belt, extremely good belt characteristics can be obtained as compared with the prior art.

Examples 2-8
Using 100 parts by weight of PPS resin (manufactured by Dainippon Ink and Chemicals, Inc., trade name: LD-10) and the additive resin in the number of parts shown in Table 2 below, 100 parts by weight of these resin components are electrified. A conductive endless belt was produced in the same manner as in Example 1 except that 15 parts by weight of black (manufactured by Denki Kagaku Kogyo Co., Ltd.) was added and melt-kneaded by a biaxial kneader.

The strength, elongation and Izod impact strength of the conductive endless belts obtained in the above examples were measured. The strength and elongation were measured under the following conditions.
Apparatus: manufactured by Shimadzu Corporation, tensile tester EZ test (analysis software: Trappezium)
Sample: Dumbbell shape (length 100 mm x width 10 mm x standard thickness 100 μm)
Tensile speed: 5mm / sec
Data sampling interval: 100 msec
Measuring method: slope at 0.5 to 0.6% elongation (tangent method described in JIS K7113 if any)
Measurement environment: Room temperature (23 ± 3 ° C, 55 ± 10% RH)
The Izod impact strength was measured at 23 ° C. according to ASTM D-256. These results are also shown in Table 2 below.

１）商品名 ＢＸ５０５、三菱エンジニアリングプラスチックス（株）製
２）商品名 ＴＱＢ−ＯＴ、帝人化成（株）製
３）商品名 ２０２６Ｂ、宇部興産（株）製
４）商品名 Ｕ−８０００、帝人化成（株）製
５）商品名 オーラム４５０、三井化学（株）製
６）商品名 ベクトラＡ９５０、ポリプラスチックス（株）製

1) Product name BX505, manufactured by Mitsubishi Engineering Plastics Co., Ltd. 2) Product name TQB-OT, Teijin Chemicals Co., Ltd. 3) Product name 2026B, Ube Industries, Ltd. 4) Product name U-8000, Teijin Chemicals 5) Product name Aurum 450, Mitsui Chemicals Co., Ltd. 6) Product name Vectra A950, Polyplastics Co., Ltd.

  From the results of Table 2 above, the properties of strength, elongation, and Izod impact strength can be obtained in a well-balanced manner even when each resin is added to the case where the PPS resin is used alone. It turns out that it is obtained.

Examples 9-12
100 parts by weight of PPS resin (Dainippon Ink Chemical Co., Ltd., trade name: LD-10) and the number of parts of thermoplastic elastomer shown in Table 2 below (Dainippon Ink Chemical Co., Ltd., trade name) Example 1 except that 15 parts by weight of electrified black (manufactured by Denki Kagaku Kogyo Co., Ltd.) was added to 100 parts by weight of these resin components and melt-kneaded by a twin-screw kneader. In the same manner, a conductive endless belt was produced.

  The strength, elastic modulus, elongation rate, and durability of the conductive endless belt obtained in each of the above Examples were measured under the same conditions as in Examples 2-8. The results are shown as an index with Example 9 with no thermoplastic elastomer added as 100. In either case, the larger the value, the better the performance. These results are also shown in Table 3 below.

  From the results of Table 3 above, it can be seen that the addition amount of the thermoplastic elastomer is preferably about 1 to 5 parts by weight with the best balance of the properties.

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. 5 is a schematic diagram illustrating an intermediate transfer type image forming apparatus 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)

Claims (15)

A conductive endless belt characterized by comprising a polyphenylene sulfide resin, a polymer alloy of a polyphenylene sulfide resin and another thermoplastic resin, or a polymer blend of a polyphenylene sulfide resin and another thermoplastic resin as a base material. The conductive endless belt according to claim 1, wherein the thermoplastic resin is selected from the group consisting of a polyphenylene ether resin, a polyalkylene naphthalate resin, a polyamide resin, a polyarylate resin, a polyimide resin, and a liquid crystal polymer. The conductive endless belt according to claim 1, wherein the thermoplastic resin is a thermoplastic elastomer. The conductive endless belt according to claim 3, wherein the thermoplastic elastomer is selected from the group consisting of a polyester elastomer, an olefin elastomer, and a styrene elastomer. The conductive endless belt according to claim 1, wherein a conductive material is added as a functional component. The conductive endless belt according to claim 5, wherein the conductive material is carbon black and is added in an amount of 0.1 to 100 parts by weight with respect to 100 parts by weight of the resin component. The conductive endless belt according to claim 1, which has a volume resistance of 10 ⁰ to 10 ¹³ Ω · cm. The conductive endless belt according to claim 1, wherein a reinforcing material is added. The conductive endless belt according to claim 8, wherein the reinforcing material is an inorganic compound having an aspect ratio of 5 or more. The conductive endless belt according to claim 1, further comprising: a fitting portion that fits with the driving member on a surface that contacts the driving member. The conductive endless belt according to claim 10, wherein the fitting portion is a protruding ridge continuously protruding along the rotation direction. 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. The conductive endless belt according to claim 1, wherein the conductive endless belt is used as a 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. The conductive endless belt according to claim 1, which is used for an intermediate transfer member. 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. 2. The conductive endless belt according to claim 1, wherein the conductive endless belt is used for a tandem intermediate transfer member for transferring the image to a recording medium. An image forming apparatus using the conductive endless belt according to claim 1.

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