JP4473614B2 - Conductive endless belt and image forming apparatus using the same - Google Patents

Description

  The present invention relates to a conductive endless belt (hereinafter also simply referred to as a “belt”) and an image forming apparatus using the same, and more particularly, to electrostatic recording in an electrophotographic apparatus such as a copying machine or a printer, an electrostatic recording apparatus, or the like. In the process, a conductive material used for transferring a toner image formed by supplying 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 onto a recording medium such as paper. The present invention relates to a conductive endless belt 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 toner is supplied onto the photosensitive member to visualize the electrostatic latent image, 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 the toner images are formed in a row, 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 28 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 an endless belt-like conductive endless belt such as the intermediate transfer member, a semiconductive resin film belt and a rubber belt provided with a fiber reinforcement are mainly used. Among these, as resin film belts, those using various resin materials as base materials are known. For example, in the present inventors, thermoplastic polyamide (PA) or a polymer of this and a thermoplastic elastomer is used. A conductive endless belt (Patent Document 1) that is improved in bending durability by using a blend or a polymer alloy (Patent Document 1) as a base material, and a PA to improve charging characteristics when a high voltage is applied. , Acrylonitrile-butadiene-styrene (ABS) resin, thermoplastic polyacetal (POM), any two or more polymer alloys or polymer blends thereof, or any one or more of these and a thermoplastic resin A polymer alloy or polymer blend is used as a base material, and a polymer conductive agent is added. It proposes the like becomes conductive endless belt (Patent Document 2).
JP 2001-350347 A (Claims etc.) JP 2003-91177 A (Claims etc.)

  Incidentally, it is generally known that a belt made of PA is excellent in flexibility and tearability, and a belt made of ABS resin is excellent in rigidity. Therefore, in a belt using these, it is possible to obtain a desired high performance utilizing individual characteristics.

  However, in a belt using only PA, elongation due to creep may occur depending on conditions under high temperature and high humidity, and a belt using only ABS resin is high in rigidity but lacks flexibility. There was a case where cracking due to durability occurred. Therefore, it has been desired to realize a belt that can satisfy the required performance as a belt more satisfactorily without causing such problems.

  Accordingly, an object of the present invention is to generate cracks during durability by highly balancing rigidity and flexibility in resin film belts used in various image forming apparatuses of tandem, intermediate transfer, and tandem intermediate transfer systems. In particular, it is an object of the present invention to provide a conductive endless belt having improved characteristics at high temperature and high humidity and an image forming apparatus using the same.

  As a result of intensive studies, the present inventors have found that the above object can be achieved 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) Polymer alloy or polymer blend of thermoplastic polyamide and acrylonitrile-butadiene-styrene resin, (b) Polymer alloy or polymer blend of thermoplastic polyamide and acrylonitrile-butadiene-styrene resin, and polyamide-based thermoplastic elastomer It is characterized in that a polymer blend or (c) a polymer alloy of thermoplastic polyamide, acrylonitrile-butadiene-styrene resin and polyamide-based thermoplastic elastomer is used as a base material, and carbon black is added.

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) Polymer alloy or polymer blend of thermoplastic polyamide and acrylonitrile-butadiene-styrene resin, (b) Polymer alloy or polymer blend of thermoplastic polyamide and acrylonitrile-butadiene-styrene resin, and polyamide-based thermoplastic elastomer It is characterized in that a polymer blend or (c) a polymer alloy of thermoplastic polyamide, acrylonitrile-butadiene-styrene resin and polyamide-based thermoplastic elastomer is used as a base material, and carbon black is added.

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.
(A) Polymer alloy or polymer blend of thermoplastic polyamide and acrylonitrile-butadiene-styrene resin, (b) Polymer alloy or polymer blend of thermoplastic polyamide and acrylonitrile-butadiene-styrene resin, and polyamide-based thermoplastic elastomer It is characterized in that a polymer blend or (c) a polymer alloy of thermoplastic polyamide, acrylonitrile-butadiene-styrene resin and polyamide-based thermoplastic elastomer is used as a base material, and carbon black is added.

  In the belt of the present invention, it is preferable that a compatibilizing agent is further added. As the compatibilizing agent, one containing glycidyl methacrylate or maleic anhydride can be suitably used. The amount of the compatibilizer is preferably 30 parts by weight or less with respect to 100 parts by weight of the base material.

Furthermore, the addition amount of the carbon black is preferably in the range of 0.01 to 40 parts by weight with respect to 100 parts by weight of the base material, whereby the volume resistance value is 10 ⁶ Ω · cm or more and 10 ^17. It can be in the range of Ω · cm or less. Furthermore, it is preferable that the belt of the present invention is provided with a fitting portion that is fitted to the driving member on the surface in contact with the driving member.

  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 can achieve a high degree of both rigidity and flexibility by using a combination of the specific polymer materials as described above for the base material, and when used alone. It has become possible to prevent the occurrence of cracks during durability, which has been a problem, and to improve the characteristics particularly at high temperatures and high humidity. Further, since carbon black is used as the conductive material, it has good performance in charging characteristics. 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 provided without causing a problem of defects caused by the belt even when used for a long period of time. it can. The combined use of PA and ABS resin as the base material of the belt is also described in Patent Document 2 described above, but this is the first time that the effect of preventing the occurrence of cracks during durability is obtained. This is a finding.

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. Are transferred to form a color image.

  In the conductive endless belt of the present invention, the base material is a polymer alloy or polymer blend of thermoplastic polyamide (PA) and acrylonitrile-butadiene-styrene (ABS) resin, or one of these and PA-based thermoplastic. It is important to use a polymer alloy or polymer blend with the elastomer. By using PA and ABS together as a base material, it is possible to obtain a belt that achieves both high rigidity and flexibility, improved characteristics at high temperatures and high humidity, and prevention of cracking during durability. It became.

  The thermoplastic polyamide according to the present invention is one of the resins that have been used for a long time as a material with good wear resistance, and is excellent in strength, impact resistance, etc., and can be easily obtained in the market. Can do. There are several types of PA, but in the present invention, nylon 12 (hereinafter referred to as “PA12”), for example, manufactured by Toray Industries, Inc., trade names: Rilsan AESN O TL and Daicel Huls Co., Ltd. Product name: DAIAMID L2101, DAIAMID L1940, Ube Industries, Ltd., trade name: UBESTAT 3024U, etc. can be suitably used. PA12 is superior to other PAs in dimensional stability with respect to environmental fluctuations. PA6 can also be used suitably. By using such various thermoplastic polyamides as the base material of the conductive endless belt, it is possible to obtain a conductive endless belt having no variation in resistance and excellent in strength, particularly bending durability. The PA12 used in the present invention preferably has a number average molecular weight of 7000 to 100,000, more preferably 13,000 to 40,000.

  The acrylonitrile-butadiene-styrene (ABS) resin according to the present invention is a thermoplastic resin excellent in impact resistance and dimensional stability, and can be easily obtained in the market. Specifically, for example, Daicel Polymer Co., Ltd. product names: Sebian V320, Sebian V680 and the like can be representatively used. By using such an ABS resin as a base material for a conductive endless belt, there can be obtained a conductive endless belt having no variation in resistance, excellent strength, in particular, bending resistance, and high dimensional accuracy.

  Furthermore, specific examples of polymer alloy of PA and ABS resin include, for example, Daicel Polymer Co., Ltd., trade name: Novalloy A1500 (PA6 / ABS resin), but is not limited thereto. Absent. Furthermore, examples of the PA-based thermoplastic elastomer include Ube Industries, Ltd., trade name: PAE1201U (polyamide elastomer), but are not limited thereto.

  In addition, as a suitable compounding ratio of PA and ABS resin in the polymer alloy or polymer blend of the base material, it is about in the range of 99: 1 to 55:45 by weight ratio. By making the blending ratio of PA and ABS resin within the above range, the combined effect of both resins according to the present invention can be obtained more favorably.

  In the present invention, carbon black as a conductive material is added to the substrate. Such carbon black is not particularly limited, and 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 General-purpose materials such as applied color ink carbon, pyrolytic carbon, natural graphite, and artificial graphite can be appropriately selected and used.

The amount of carbon black added is preferably 0.01 to 40 parts by weight, more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the base material. Can be adjusted to 10 ⁶ Ω · cm or more and 10 ¹⁷ Ω · cm or less, more preferably 10 ⁸ Ω · cm or more and 10 ¹⁵ Ω · cm or less. If the amount of carbon black added is less than 0.01 parts by weight, such a resistance level cannot be achieved. On the other hand, if it exceeds 40 parts by weight, physical properties such as bending durability may be affected. It is not preferable.

  Further, in the belt of the present invention, it is preferable that a compatibilizing agent is further added, whereby the alloy / blend property of PA and ABS resin can be improved, and the folding resistance can be improved. Such a compatibilizing agent is not particularly limited, but for example, those containing glycidyl methacrylate (GMA) or maleic anhydride (MAH) have a large effect and are suitable. Specifically, the product name: Modiper A4200, A4400, A8400 etc. can be mentioned by Nippon Oil & Fat Co., Ltd. The compatibilizing agent can be added within a range not impairing other properties, and is preferably 30 parts by weight or less, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the base material.

Moreover, in this invention, another electroconductive material can be added to a base material as a functional component, and electroconductivity provision and adjustment can be performed auxiliary. The conductive material is not particularly limited, and lauryltrimethylammonium, stearyltrimethylammonium, octadecyltrimethylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, modified fatty acid / dimethylethylammonium perchlorate, chlorate, borofluoride Cationic surfactants such as quaternary ammoniums such as hydrohalides, sulfates, etosulphate salts, benzyl halides (such as verzyl bromide and benzyl chloride); aliphatic sulfonic acids, higher alcohol sulfates Anionic surfactants such as salts, higher alcohol ethylene oxide addition sulfates and higher alcohol phosphates; amphoteric surfactants such as various betaines; higher alcohol ethylene oxides, polyethylene glycol fats 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 or 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. Examples thereof include conductive agents; metals and metal oxides such as tin oxide, titanium oxide, zinc oxide, nickel, and copper; conductive polymers such as polyaniline, polypyrrole, and polyacetylene.

  In addition, a polymer ion conductive agent can be used as the conductive material. Examples of the polymeric ion conductive agent that can be used in the present invention include those described in JP-A-9-227717, JP-A-10-120924, and JP-A-2000-327922. However, it is not particularly 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 oligoethoxylated acrylate or methacrylate, oligoethoxylated for aromatic ring 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 a suitable polymer ion conductive agent is commercially available as Irgastat (registered trademark) P18 and Irgastat (registered trademark) P22 (both manufactured by Ciba Specialty Chemicals Inc.) and Perestat NC6321 (manufactured by Sanyo Chemical Co., Ltd.). It can be obtained.

  The addition amount of these other conductive materials is preferably 0.01 to 30 parts by weight, more preferably about 0.1 to 20 parts by weight with respect to 100 parts by weight of the base material.

  In the present invention, other functional components can be appropriately added in addition to the above-described components within a range not impairing the effects of the present invention. 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, a coloring agent may be added to color the belt.

  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.

  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. 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 driving roller or driving gear for rotating the intermediate transfer member 20 of the present invention. The application conditions such as application of weighting alternating current can be selected as appropriate.

  Further, the method for producing the conductive endless belt of the present invention is not particularly limited, and can be obtained, for example, by kneading a resin material as a main component and a functional component such as a conductive material by a biaxial kneader. The kneaded product can be produced by extrusion molding using an annular die. Alternatively, a powder coating method such as electrostatic coating, a dip method, or a centrifugal casting method can also be suitably employed.

Hereinafter, the present invention will be specifically described by way of examples.
Examples 1-20 and Comparative Examples 1-3
Mixtures blended in the proportions shown in Tables 1 and 2 below were melt-kneaded by a biaxial kneader at a predetermined molding temperature (see Table 2 below). Thereafter, the obtained kneaded product was extruded by an annular die attached to the top of a single screw extruder to obtain a conductive endless belt having an inner diameter of 140 mm, a thickness of 100 μm, and a width of 247 mm. The physical properties of the obtained belts of the examples and comparative examples were measured according to the following procedures.

Measurement of dynamic tensile modulus (E ′) The dynamic tensile modulus was 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 mmsec
Measuring method: inclination at 0.5 to 0.6% elongation (when described, tangent method described in JIS)
Measurement environment: Room temperature (23 ± 3 ° C, 55 ± 10% RH)

At a measurement temperature of volume resistivity of 23 ° C. and a relative humidity of 50%, a measuring device having a measurement voltage of 100 V and 500 V is used as a measuring device by connecting a sample chamber R12704A to an resistance meter R8340A manufactured by ADVANTEST. Under the two conditions, the volume resistivity was measured.

Measurement of the number of breaks The number of breaks was measured using an MIT fatigue resistance tester manufactured by Toyo Seiki Co., Ltd., and the result was shown as an index with Comparative Example 8 as 20. The higher the number, the better the result.

Actual Machine Test The belts of each Example and Comparative Example were mounted on a tandem type image forming apparatus using the transfer conveyance belt shown in FIG. 2, and the transfer operation was repeated to conduct a durability test on 100,000 sheets of A4 paper. The results were evaluated for image quality, rotational durability, durability at 10 times the required number of rotational durability, and contamination. Moreover, the presence or absence of the elongation defect when the durability test was similarly performed under a high temperature and high humidity environment (35 ° C. × 85% RH) was also evaluated. The rotation durability is an evaluation as to whether or not the belt is torn due to a crack generated on the surface or end due to the rotation, resulting in breakage or no adverse effect on image characteristics, and 10 times the required number of rotation durability. The durability at is an evaluation of rotational durability at 10 times the required number of the durability test, that is, 1 million sheets.
The blending contents of each example and comparative example are shown in Tables 1 and 2 below, and the molding temperatures and the results of the above measurements are shown in Tables 3 and 4, respectively. In addition, all the compounding quantities in following Table 1 and Table 2 are a weight part.

＊１）ＰＡ１２：熱可塑性ポリアミド、宇部興産（株）製、商品名 ＵＢＥＳＴＡＴ ３０２４Ｕ
＊２）ＡＢＳ：アクリロニトリル−ブタジエン−スチレン樹脂、ダイセルポリマー（株）製、商品名 セビアンＶ６８０
＊３）ＰＣ：ポリカーボネート樹脂、帝人化成（株）製、商品名 パンライトＫ１３００Ｙ
＊４）高分子イオン導電剤：チバ・スペシャルティ・ケミカルズ・インコーポレーテッド製、商品名 Ｉｒｇａｓｔａｔ Ｐ１８
＊５）電化ブラック：商品名、電気化学工業（株）製、カーボンブラック（粒状）
＊６）ＦＥＦカーボン：商品名、旭カーボン（株）製、カーボンブラック
＊７）モディパーＡ４２００：商品名、日本油脂（株）製、エチレン・グリシジルメタクリレート共重合体（ＥＧＭＡ）−ｇ−ポリメチルメタクリレート（ＰＭＭＡ）、組成比７０／３０（重量％）
＊８）モディパーＡ４４００：商品名、日本油脂（株）製、ＥＧＭＡ−ｇ−アクリロニトリル・スチレン共重合体（ＡＳ）、組成比７０／３０（重量％）
＊９）モディパーＡ８４００：商品名、日本油脂（株）製、エチレン・エチルアクリレート・無水マレイン酸共重合体（Ｅ／ＥＡ／ＭＡＨ）−ｇ−ＡＳ、組成比７０／３０（重量％）
＊１０）モディパーＡ１１００：商品名、日本油脂（株）製、低密度ポリエチレン（ＬＤＰＥ）−ｇ−ポリスチレン（ＰＳ）、組成比７０／３０（重量％）

* 1) PA12: Thermoplastic polyamide, manufactured by Ube Industries, Ltd., trade name UBESTAT 3024U
* 2) ABS: Acrylonitrile-butadiene-styrene resin, manufactured by Daicel Polymer Co., Ltd., trade name Ceviane V680
* 3) PC: Polycarbonate resin, manufactured by Teijin Chemicals Ltd., trade name: Panlite K1300Y
* 4) Polymeric ion conducting agent: Ciba Specialty Chemicals, Inc., trade name: Irgastat P18
* 5) Electric black: Trade name, manufactured by Denki Kagaku Kogyo Co., Ltd., carbon black (granular)
* 6) FEF carbon: trade name, manufactured by Asahi Carbon Co., Ltd., carbon black * 7) Modiper A4200: trade name, manufactured by NOF Corporation, ethylene glycidyl methacrylate copolymer (EGMA) -g-polymethyl methacrylate (PMMA), composition ratio 70/30 (% by weight)
* 8) Modiper A4400: trade name, manufactured by NOF Corporation, EGMA-g-acrylonitrile / styrene copolymer (AS), composition ratio 70/30 (% by weight)
* 9) Modiper A8400: trade name, manufactured by NOF Corporation, ethylene / ethyl acrylate / maleic anhydride copolymer (E / EA / MAH) -g-AS, composition ratio 70/30 (wt%)
* 10) Modiper A1100: trade name, manufactured by NOF Corporation, low density polyethylene (LDPE) -g-polystyrene (PS), composition ratio 70/30 (% by weight)

＊１１）ＰＡ１２エラストマー：ポリアミドエラストマー、宇部興産（株）製、商品名 ＰＡＥ１２０１Ｕ

* 11) PA12 elastomer: polyamide elastomer, manufactured by Ube Industries, Ltd., trade name PAE1201U

  As can be seen from the results of Tables 3 and 4 above, according to the present invention, high strength, in particular, good bending durability, as well as generation of cracks during durability and poor elongation under high temperature and high humidity. It is possible to realize a conductive endless belt that does not generate and has good charging performance. Further, in the belts of Examples 7 to 16, 19 and 20 in which a compatibilizing agent was blended, durability could be further improved. Therefore, according to the image forming apparatus of the present invention using the conductive endless belt of the present invention, it is possible to provide a good image that does not cause a defect even after long-term use.

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)

Claims (10)

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) Polymer alloy or polymer blend of thermoplastic polyamide and acrylonitrile-butadiene-styrene resin, (b) Polymer alloy or polymer blend of thermoplastic polyamide and acrylonitrile-butadiene-styrene resin, and polyamide-based thermoplastic elastomer (C) A conductive endless belt comprising a polymer alloy of thermoplastic polyamide, acrylonitrile-butadiene-styrene resin and polyamide-based thermoplastic elastomer as a base material, and carbon black added thereto. 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) Polymer alloy or polymer blend of thermoplastic polyamide and acrylonitrile-butadiene-styrene resin, (b) Polymer alloy or polymer blend of thermoplastic polyamide and acrylonitrile-butadiene-styrene resin, and polyamide-based thermoplastic elastomer (C) A conductive endless belt comprising a polymer alloy of thermoplastic polyamide, acrylonitrile-butadiene-styrene resin and polyamide-based thermoplastic elastomer as a base material, and carbon black added thereto. 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) Polymer alloy or polymer blend of thermoplastic polyamide and acrylonitrile-butadiene-styrene resin, (b) Polymer alloy or polymer blend of thermoplastic polyamide and acrylonitrile-butadiene-styrene resin, and polyamide-based thermoplastic elastomer (C) A conductive endless belt comprising a polymer alloy of thermoplastic polyamide, acrylonitrile-butadiene-styrene resin and polyamide-based thermoplastic elastomer as a base material, and carbon black added thereto.   The conductive endless belt according to any one of claims 1 to 3, further comprising a compatibilizer.   The conductive endless belt according to claim 4, wherein the compatibilizer contains glycidyl methacrylate or maleic anhydride.   The conductive endless belt according to claim 4 or 5, wherein the compatibilizing agent is added at 30 parts by weight or less with respect to 100 parts by weight of the base material.   The conductive endless belt according to any one of claims 1 to 6, wherein an amount of the carbon black added is in a range of 0.01 to 40 parts by weight with respect to 100 parts by weight of the base material. The conductive endless belt according to any one of claims 1 to 7, wherein the volume resistance value is in a range of 10 ⁶ Ω · cm to 10 ¹⁷ Ω · cm.   The conductive endless belt according to any one of claims 1 to 8, wherein a fitting portion that is fitted to the driving member is provided on a surface that contacts the driving member.   An image forming apparatus using the conductive endless belt according to claim 1.

Images