JP4807837B2 - Conductive endless belt - Google Patents

Description

  The present invention develops on 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 (LBP) 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 by supplying an agent to 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. Here, in any of the above-described apparatuses, the arrangement order of the toners used for development is not particularly limited, and can be arbitrarily selected.

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

Conventionally, as such an endless belt-shaped transfer member, a semiconductive resin film belt and a rubber belt having a fiber reinforcement are mainly used. Among these, as semiconductive resin film belts, for example, those in which carbon black is blended with polycarbonate, those based on polyalkylene terephthalate, and materials based on polyimide have been proposed. Further, for example, Patent Document 1 discloses thermoplastic polyamide (PA), acrylonitrile-butadiene-styrene (ABS) resin, thermoplastic polyacetal (POM), any two or more of these polymer alloys or polymer blends, and One type selected from the group consisting of a polymer alloy or a polymer blend of any one or more of these and a thermoplastic resin, and a fluororesin as a base material, and a polymer ion conductive agent is added. A conductive endless belt is disclosed.
JP 2004-272210 A (Claims etc.)

  Among the above, in the image forming apparatus using the intermediate transfer method, the toner is accumulated on the intermediate transfer member 20 to transfer the image as described above, so that the toner remains on the belt with repeated use. In some cases, such residual toner touches the surface of the belt when it is durable, causing image defects and the like. Also in the tandem transfer system, the toner adhering at the time of transfer abnormality such as position detection or paper jam may remain on the belt to cause the same problem.

  With respect to this problem, according to the technique described in Patent Document 1, it is possible to realize a conductive endless belt having excellent toner releasability in addition to various belt performances such as strength. However, the belt described in Patent Document 1 has not been studied for toner releasability in a high-temperature and high-humidity environment, and is insufficient in this respect.

  Accordingly, an object of the present invention is to provide a conductive endless belt capable of exhibiting excellent toner releasability even in a high-temperature and high-humidity environment while ensuring important characteristics of the belt such as mechanical strength, and an image using the same. It is to provide a forming apparatus.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have both the belt characteristics such as mechanical strength and the excellent toner releasability in a high-temperature and high-humidity environment by adopting the following configuration. The inventors have found that a belt can be realized and have completed the present invention.

That is, the 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 onto its surface. In the conductive endless belt for the intermediate transfer member that holds the transfer and transfers it to the recording medium,
A conductive agent is added to a base material containing a crystalline polyolefin and an amorphous copolymer composed of a cyclic olefin and a linear olefin at a weight ratio of 95 to 50/5 to 50. It is.

Further, another conductive endless belt of the present invention is configured such that a recording medium held by electrostatic attraction is circulated by a driving member and conveyed to four types of image forming bodies, and each toner image is sequentially transferred to the recording medium. In tandem transfer and transfer endless belts for transfer,
A conductive agent is added to a base material containing a crystalline polyolefin and an amorphous copolymer composed of a cyclic olefin and a linear olefin at a weight ratio of 95 to 50/5 to 50. It is.

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 conductive agent is added to a base material containing a crystalline polyolefin and an amorphous copolymer composed of a cyclic olefin and a linear olefin at a weight ratio of 95 to 50/5 to 50. It is.

  In the present invention, the weight ratio of the crystalline polyolefin to the amorphous copolymer is preferably in the range of 95 to 70/5 to 30. Further, as the conductive agent, either one or both of a polymer antistatic agent and carbon black can be preferably used. Furthermore, as the crystalline polyolefin, polyethylene (PE) or polypropylene (PP) resin can be suitably used.

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

  According to the present invention, it is possible to realize a conductive endless belt that can exhibit excellent toner releasability in a high-temperature and high-humidity environment and can also secure belt characteristics such as mechanical strength by the above configuration. Is possible. Therefore, according to the image forming apparatus using the belt of the present invention, it is possible to provide a good image without causing problems such as image defects due to residual toner or fusion.

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.

  The conductive endless belt of the present invention is characterized in that it comprises a crystalline polyolefin and an amorphous copolymer composed of a cyclic olefin and a linear olefin as a base material and contains a conductive agent. By using the crystalline polyolefin and the above-mentioned predetermined amorphous copolymer containing a cyclic olefin as a base material, it is possible to obtain an effect of improving toner releasability in a high-temperature and high-humidity environment by the former and the latter. As a result, the effect of improving the mechanical strength can be obtained without impairing the surface properties. As a result, a belt having both toner releasability and mechanical strength can be realized.

  The crystalline polyolefin used in the present invention is not particularly limited, but PE or PP resin can be suitably used. Among these, as the PP resin, a propylene homopolymer and a random copolymer of propylene and an α-olefin other than propylene are preferable. Although a block copolymer can be used, it is inferior in terms of glossiness and whitening resistance. Other α-olefins other than propylene include ethylene or α-olefins having 4 to 12 carbon atoms, such as 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 4 -Methyl-1-pentene or the like can be used. Among them, a homopolymer of propylene and a random copolymer in which 70% by weight or more of all constituent monomer components are propylene are preferable. From the viewpoint of moldability and the like, 230 ° C. and 2.16 kg in accordance with JIS K7210. More preferably, the melt flow rate is from 0.1 to 50 g / 10 min.

（式中、Ｒは水素原子またはアルキル基を示し、非結晶性コポリマーの全量（Ｘ＋Ｙ）に対する環状オレフィンの含有量（Ｙ）は６０〜８０重量％である）で示されるものを用いることができる。具体的には例えば、市販品として、ポリプラスチックス（株）製のＴＯＰＡＳ（登録商標）シリーズを好適に用いることができる。 Moreover, as an amorphous copolymer consisting of a cyclic olefin and a linear olefin, the following general formula,

(Wherein R represents a hydrogen atom or an alkyl group, and the content (Y) of the cyclic olefin with respect to the total amount (X + Y) of the amorphous copolymer is 60 to 80% by weight) can be used. . Specifically, for example, a TOPAS (registered trademark) series manufactured by Polyplastics Co., Ltd. can be suitably used as a commercial product.

  The weight ratio of the crystalline polyolefin and the amorphous copolymer in the belt of the present invention can be in the range of 95 to 50/5 to 50, and the compounding amount of the crystalline polyolefin is larger than this range. If the amount of the amorphous copolymer is small, the mechanical strength is weak. On the other hand, the amount of the crystalline polyolefin is less than this range, and if the amount of the amorphous copolymer is large, the flex resistance deteriorates. Is also not preferred.

  In addition, as the conductive agent used in the belt of the present invention, a polymeric antistatic agent (polymeric ionic conductive agent) and carbon black can be used, and these may be used alone or in combination. When a polymer type antistatic agent is used, resistance variation is reduced and an effect of increasing uniformity can be obtained. When carbon black is used, the electrical resistance is less dependent on the environment, There is an advantage that the mechanical strength can be improved. In addition, the combined use of these materials is preferable in that the addition of the antistatic agent can be made small, and the cost can be reduced and the elastic modulus can be prevented from lowering.

  Specific examples of carbon black include ketjen black, acetylene black, carbon black for rubber such as SAF, ISAF, HAF, FEF, GPF, SRF, FT, and MT, carbon black for ink such as oxidized carbon black, Examples thereof include pyrolytic carbon black. Moreover, as a compounding quantity of carbon black, it can be set as about in the range of 5-30 weight part with respect to 100 weight part of resin components of a base material.

  Examples of the polymer antistatic agent are described in JP-A-9-227717, JP-A-10-120924, JP-A-2000-327922, JP-A-2005-60658, and the like. 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 acid ester, polymethacrylic acid ester, polyacrylonitrile, polyvinyl alcohol, polyvinyl acetate, polyamide 6, polyamide 12, etc., polyurethane or polyester, and component (B) is an oligoethoxylated acrylate or methacrylate, Styrene, polyether urethane, polyether urea, polyether amide, polyether ester amide or polyester-ether block copolymer oligoethoxylated for the aromatic ring, and component (C) is inorganic or low An alkali metal, alkaline earth metal, zinc or ammonium salt in an amount organic protonic acids, _{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 .

Among these, as the component (B), a polymer ionic conductive agent containing a polyether amide component, a polyether ester amide component or a polyester-ether block copolymer component is suitable, and in addition to this, the component (C) It is preferable to contain a low molecular ion conductive agent component. 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 polyamide 12 or polyamide 6 are particularly preferable. As the low molecular ion conductive agent component of component (C), a polymer ion conductive agent containing NaClO ₄ is particularly suitable. Such a polymeric ionic conductive agent is readily available on the market as, for example, Irgastat (registered trademark) P18 and Irgastat (registered trademark) P22 (both manufactured by Ciba Specialty Chemicals, Inc.).

  A block copolymer in which a polyolefin block and a hydrophilic polymer block are repeatedly and alternately bonded through an ester bond, an amide bond, an ether bond, a urethane bond, an imide bond, etc. It can be suitably used as a molecular ion conductive agent. Examples of such polyolefins include polyolefins having functional groups such as a carboxyl group, a hydroxyl group, and an amino group at both ends of the polymer, and polypropylene and polyethylene are particularly preferable.

  Further, as the hydrophilic polymer, a polyether diol such as polyoxyalkylene having a hydroxyl group as a functional group, a polyether ester amide composed of a polyamide having both terminal carboxyl groups and a polyether diol, a polyamide imide and a polyether diol Polyetheramide imide composed of polyester, polyether ester composed of polyester and polyether diol, polyether amide composed of polyamide and polyether diamine, etc. can be used. preferable. For example, polyoxyethylene (polyethylene glycol) and polyoxypropylene (polypropylene glycol) having hydroxyl groups at both terminals are used.

Such a block copolymer that can be used as a polymer type antistatic agent in the present invention is readily available on the market as Pelestat 300, 303 (manufactured by Sanyo Chemical Co., Ltd.). In addition, by incorporating the lithium compound LiCF ₃ SO ₃ into the block copolymer, the effect of maintaining the antistatic effect can be obtained even if the addition amount is reduced, and the mixture of the block copolymer and the lithium compound Sanconol TBX-310 (manufactured by Sanko Chemical Co., Ltd.) is commercially available.

The compounding amount of the polymer type antistatic agent in the present invention can be in the range of 1 to 40 parts by weight, preferably in the range of 5 to 30 parts by weight with respect to 100 parts by weight of the resin component of the base material. To do. Thereby, the volume resistance value of the belt can be adjusted to, for example, about 10 ⁷ to 10 ¹⁴ Ω · cm, preferably about 10 ⁸ to 10 ^12.5 Ω · cm.

  When a polymer antistatic agent is used as the conductive material, a compatibilizing agent may be added in order to increase the compatibility between the resin component of the base material and the polymer antistatic agent. Examples of compatibilizers that can be suitably used in the present invention include EVA / EPDM / polyolefin graft copolymers, polyolefin graft copolymers, and reactive (GMA and MAH-containing) polyolefin graft copolymers, P (St-co- GMA), EGMA, P (Et-co-EA-co-MAH), SEBS and its maleic anhydride modified product, oxazoline group-containing styrene-based or acrylonitrile-styrene-based polymer, maleic anhydride-modified EPDM, maleic anhydride-modified PE , Maleic anhydride modified PP, maleic anhydride modified EVA, styrene / maleic anhydride copolymer, SAN graft EPDM, reactive polystyrene, polycaprolactone-b-polystyrene, reactive styrene / acrylonitrile copolymer -, Imidized polyacrylate, ethylene-glycidyl methacrylate acrylic acid copolymer, chlorinated polyethylene, reactive phenoxy, silane compound, peroxide polymer, polycaprolactone, etc. (abbreviations in the above list are EVA: ethylene vinyl acetate, respectively) Copolymer, EPDM: ethylene-propylene-diene copolymer, EGMA: ethylene-glycidyl methacrylate copolymer, SEBS: styrene-ethylene-butadiene-styrene copolymer, GMA: glycidyl methacrylate, MAH: maleic anhydride EA: ethyl acrylate) and the like, and the compatibilizer is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the total amount of the base material and the polymer antistatic agent. By adding it, the compatibility of both is improved. Enables homogeneous and good dispersion of the base material of the polymer type antistatic agent, it is possible to obtain a high-performance conductive endless belt.

In the present invention, in addition to carbon black and / or polymer type antistatic agent, other conductive materials can be added to impart and adjust conductivity supplementarily. For example, lauryltrimethylammonium , Stearyltrimethylammonium, octadecyltrimethylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, dechlorinated fatty acid / dimethylethylammonium perchlorate, chlorate, borofluoride, sulfate, ethosulphate salt, benzyl halide Cationic surfactants such as quaternary ammonium such as salts (Vergil bromide, benzyl chloride, etc.); aliphatic sulfonic acid, higher alcohol sulfate, higher alcohol ethylene oxide addition sulfate, higher alcohol phosphate Shade Emissions surfactant; nonionic surfactants such as various betaine; higher alcohol ethylene oxide, polyethylene glycol fatty acid esters, polyhydric alcohol fatty acid antistatic agent such as a nonionic antistatic agents such as esters, LiCF ₂ SO _2, NaClO ₄ , LiBF ₄ , NaCl, etc. Group 1 metal salts; Ca (ClO ₄ ) _2, etc. Group 2 metal salts; natural graphite, artificial graphite, etc .; tin oxide, titanium oxide, oxidation Examples thereof include metals and metal oxides such as zinc, nickel and copper; and conductive polymers such as polyaniline, polypyrrole and polyacetylene.

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

  The 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.

  In addition, 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 in FIG. 2 or the driving roller 30 in FIG. A fitting portion that fits with a fitting portion (not shown) formed on the drive member may be formed, and the conductive endless belt of the present invention is provided with such a fitting portion and drives this. Shifting in the width direction of the conductive endless belt can be prevented by running with a fitting portion (not shown) provided on the member.

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

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

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

  The conductive endless belt of the present invention can be suitably produced by extrusion molding of a resin composition containing the above base resin and a conductive agent. Specifically, for example, the conductive endless belt can be electrically conductive with a base material by a biaxial kneader. It can be produced by kneading a resin composition comprising a functional component such as an agent and extruding the obtained kneaded product using an annular die.

Hereinafter, the present invention will be described in more detail with reference to examples.
Examples 1-4 and Comparative Examples 1-3
Conductive endless belts of the examples and comparative examples were prepared with the formulations shown in Table 1 below. Specifically, each compounding component is melt-kneaded with a twin-screw kneader, and the obtained kneaded product is extruded using an annular die, whereby a conductive material having dimensions of an inner diameter of 220 mm, a thickness of 100 μm, and a width of 250 mm. A sex endless belt was obtained. The belts of the obtained examples and comparative examples were evaluated according to the following procedures.
These results are also shown in Table 1 below.

<Toner releasability>
Each belt is mounted on the image forming apparatus using the intermediate transfer belt shown in FIG. 3, and the transfer operation is repeated. Under a condition of 30 ° C. and 85% RH (high temperature and high humidity), a durability test of 100,000 A4 sheets, respectively. Went. The results were evaluated by the presence or absence of toner accumulation on the belt surface after endurance. “◯” indicates a case where there is no toner accumulation or a small amount so as not to cause a problem in image quality, and “X” indicates a case where there is a toner accumulation which causes a problem in image quality.

<Tensile breaking strength E '>
In accordance with JIS K7161, measurement was performed on a sample piece (length 150 mm, width 10 mm, thickness 100 μm, distance between marked lines 50 mm, initial distance between chucks 100 mm) prepared according to JIS K7127. It is good if it is 700 MPa or more.

<Flexibility>
In accordance with JIS P8115, measurement was performed using a sample piece having a length of 150 mm, a width of 15 mm, a thickness of 100 μm, and an initial distance of 100 mm between chucks. The case where the bending resistance was 1000 times or more was “◯”, and the case where the bending resistance was less than 1000 was “x”.

＊１）日本ポリプロ（株）製，ＥＡ−９
＊２）三井化学（株）製，ハイゼックス３３００Ｆ
＊３）ポリプラスチックス社製，ＴＯＰＡＳ ８００７（非結晶性コポリマー全量に対する環状オレフィン含有率＝６３重量％）
＊４）ダイセル化学工業（株）製，ダイアミドＬ１９４０
＊５）三洋化成工業（株）製，ペレスタット３００
＊６）電気化学工業（株）製，電化ブラック粒状

* 1) EA-9, manufactured by Nippon Polypro Co., Ltd.
* 2) Made by Mitsui Chemicals, Hi-Zex 3300F
* 3) manufactured by Polyplastics Co., Ltd., TOPAS 8007 (cyclic olefin content based on the total amount of the amorphous copolymer = 63% by weight)
* 4) Daiamide L1940, manufactured by Daicel Chemical Industries, Ltd.
* 5) Sanyo Chemical Industries, Perestat 300
* 6) Electrochemical Industry Co., Ltd., electrified black granular

  As shown in Table 1 above, the belts of the examples in which a crystalline polyolefin and an amorphous copolymer composed of a cyclic olefin and a linear olefin are used as a base material have a desired mechanical strength, high temperature and high humidity. It was confirmed that the toner has excellent toner releasability under the environment.

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 (7)

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
Conductive agent characterized in that a conductive agent is added to a substrate containing crystalline polyolefin and an amorphous copolymer composed of cyclic olefin and linear olefin at a weight ratio of 95-50 / 5-50. Sex endless belt. 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
Conductive agent characterized in that a conductive agent is added to a substrate containing crystalline polyolefin and an amorphous copolymer composed of cyclic olefin and linear olefin at a weight ratio of 95-50 / 5-50. Sex 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,
Conductive agent characterized in that a conductive agent is added to a substrate containing crystalline polyolefin and an amorphous copolymer composed of cyclic olefin and linear olefin at a weight ratio of 95-50 / 5-50. Sex endless belt.   The conductive endless belt according to any one of claims 1 to 3, wherein a weight ratio of the crystalline polyolefin and the amorphous copolymer is in a range of 95 to 70/5 to 30.   The conductive endless belt according to any one of claims 1 to 4, wherein the conductive agent is one or both of a polymer-type antistatic agent and carbon black.   The conductive endless belt according to any one of claims 1 to 5, wherein the crystalline polyolefin is polyethylene or polypropylene resin.   An image forming apparatus using the conductive endless belt according to claim 1.

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