JP2009093019A - Conductive endless belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive endless belt, which can be manufactured without using a solvent, obtained inexpensively and has transfer performance, gloss and durability equivalent to those of the conventional polyimide belt. <P>SOLUTION: The conductive endless belt used for an image forming apparatus has layered structure equipped with at least a base layer 101 and a surface layer 102 successively from an inner side, and a difference between a surface resistance value measured from the surface layer 102 side and a surface resistance value measured from the base layer 101 side is within four orders of magnitude. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

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

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

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

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

FIG. 2 shows a configuration example of the printing unit of the tandem image forming apparatus. A printing unit composed of the photosensitive drum 1, the charging roll 2, the developing roll 3, the developing blade 4, the toner supply roll 5, and the cleaning blade 6 corresponds to each toner of yellow Y, magenta M, cyan C, and black B 4 The toner images are sequentially transferred onto a sheet that is circulated by a driving roller (driving member) 9 and conveyed by a transfer conveying belt 10 to form a color image. Charging and discharging of the transfer / conveying belt are performed by the charging roll 7 and the discharging roll 8, respectively. Further, a suction roller (not shown) is used for charging the paper for sucking the paper onto the belt. Owing to these measures, generation of ozone can be suppressed. The suction roller places the paper on the transfer conveyance belt from the conveyance path and performs electrostatic adsorption on the transfer conveyance belt. Further, the sheet separation after the transfer can be performed only by the curvature separation by lowering the transfer voltage to weaken the adsorption force between the sheet and the transfer conveyance belt.

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

  On the other hand, in the case of a dielectric belt, there is no spontaneous release of injected charge, and both charge injection and discharge must be electrically controlled. However, since the charge is stably held, the sheet can be adsorbed reliably and can be conveyed with high accuracy. Since the dielectric constant is less dependent on temperature and humidity, the transfer process is relatively stable to the environment. The 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, the transfer from the photoconductor 11 to the intermediate transfer member 20 is performed by the photoconductor 11.
In the nip portion between the intermediate transfer member 20 and the intermediate transfer member 20, the primary transfer bias is applied to the intermediate transfer member 20 from the power source 61. 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 an intermediate transfer method that combines a tandem method and an intermediate transfer method. FIG. 4 illustrates an intermediate transfer type image forming apparatus that forms a color image using an endless belt-shaped intermediate transfer member.

  In the illustrated apparatus, a first developing unit 54 a to a fourth developing unit 54 d that develop the electrostatic latent images on the photosensitive drums 52 a to 52 d with yellow, magenta, cyan, and black, respectively, along the intermediate transfer member 50. The intermediate transfer members 50 are sequentially arranged, and the intermediate transfer members 50 are circulated and driven in the direction of the arrows in the drawing to sequentially transfer the four color toner images formed on the photosensitive drums 52a to 52d of the developing units 54a to 54d. As a result, a color toner image is formed on the 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 intermediate transfer member 50, reference numeral 56 denotes a recording medium feeding roller, reference numeral 57 denotes a recording medium feeding apparatus, and reference numeral 58 denotes a recording medium. 1 shows a fixing device for fixing an image by heating or the like. Reference numeral 59 denotes a power supply device (voltage applying means) for applying a voltage to the intermediate transfer member 50. The power supply device 59 transfers a toner image from the photosensitive drums 52a to 52d to the intermediate transfer member 50. The applied voltage can be reversed between the case where the image is transferred from the intermediate transfer member 50 onto the recording medium 53.

Conventionally, as a conductive endless belt used as the endless belt-like transfer / conveying belt 10 or the intermediate transfer members 20, 50, a semi-conductive resin film belt or a rubber belt having a fiber reinforcement is mainly used. Yes. Among these, as resin film belts, for example, polycarbonate (PC) mixed with carbon black, polyalkylene terephthalate as a main resin, thermoplastic polyimide as a main resin, and the like are known (for example, , See Patent Document 1).
JP-A-11-170389 (Claims)

  However, conventionally known polyimide belts have the disadvantage of being high performance but expensive. Moreover, since it is essential to use a solvent at the time of manufacture, there also existed a problem that environmental resistance had a problem and productivity was also low.

  Therefore, the object of the present invention is to solve the above problems, and can be produced without using a solvent, can be obtained at a low cost, and has transfer performance, gloss and durability comparable to conventional polyimide belts. It is an object to provide a conductive endless belt having the characteristics.

  As a result of intensive studies to solve the above problems, the present inventors set a difference in surface resistance value between the base layer side and the surface layer side within a predetermined range as a laminated structure in which the belt is divided into a plurality of layers. As a result, the secondary transfer efficiency of the belt can be improved, and the decrease in the belt gloss after printing can be suppressed. As a result, a belt having excellent durability can be obtained even if a general-purpose thermoplastic resin is used. As a result, the present invention has been completed.

That is, the conductive endless belt of the present invention is an endless belt-shaped conductive endless belt used in an image forming apparatus.
It has a laminated structure including at least a base layer and a surface layer sequentially from the inside, and the difference between the surface resistance value measured from the surface layer side and the surface resistance value measured from the base layer side is within 4 digits, To do.

  According to the present invention, it is possible to manufacture without using a solvent by using the above configuration, and it can be obtained at a low cost, and transfer performance, gloss and durability comparable to those of a conventional polyimide belt. It has become possible to realize a conductive endless belt comprising

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 or an 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, an intermediate transfer member denoted by reference numeral 50 in FIG. 4, the space between the developing units 54a to 54d including the photoconductive drums 52a to 52d and the recording medium 53 such as paper. 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. By transferring, a color image is formed. In the above description, the case of four colors of toner has been described. Needless to say, in any apparatus, the number of colors of toner is not limited to four.

  FIG. 1 is a cross-sectional view in the width direction of a conductive endless belt according to a preferred embodiment of the present invention. As shown in the figure, the conductive endless belt 100 of the present invention has a laminated structure including at least a base layer 101 and a surface layer 102 sequentially from the inside.

In the belt of the present invention, it is important that the difference between the surface resistance value measured from the surface layer 102 side and the surface resistance value measured from the base layer 101 side is within 4 digits. As a result, the secondary transfer efficiency of the belt can be improved, and a reduction in belt gloss after printing can be suppressed to obtain a high-definition image. In addition, waste toner can be reduced, which can contribute to resource saving. Specifically, for example, the surface resistance value measured from the surface layer 102 side is 1 × 10 ⁵ Ω / □ to 1 × 10 ¹⁶ Ω / □, and the surface resistance value measured from the base layer 101 side is 1 × 10 ⁵ Ω / □ to It can be set to 1 × 10 ¹⁶ Ω / □.

  In the belt of the present invention, any belt may be used as long as it satisfies the condition relating to the surface resistance value, whereby the desired effect of the present invention can be obtained, and the specific configuration of the belt is particularly limited. It is not a thing. For example, the configuration is as follows.

  As a resin material which becomes a base material of each layer including the base layer 101 and the surface layer 102, a belt material which is conventionally selected from general-purpose general-purpose thermoplastic resins, thermoplastic elastomers, blends and alloys thereof, and the like can be used. it can. In the present invention, an inexpensive belt can be obtained by using a low-cost general-purpose thermoplastic resin or thermoplastic elastomer as the base material of the belt.

  Specific examples of the thermoplastic resin include thermoplastic polyalkylene naphthalate resins (for example, polyethylene naphthalate (PEN) resin, polybutylene naphthalate (PBN) resin, etc.) and thermoplastic polyalkylene terephthalate resins (for example, Polyester resins such as polyethylene terephthalate (PET) resin, glycol modified PET (PETG) resin, polybutylene terephthalate (PBT) resin, etc.), thermoplastic polyamide (PA) (for example, PA11, PA12, PA6, PA66, PA610, PA612) , PA46, aromatic nylon (nylon 6T, 9T, MXD6, etc.), acrylonitrile-butadiene-styrene (ABS) resin, thermoplastic polyacetal (POM), thermoplastic polyarylate (PAR), thermoplastic polyester Carbonate (PC), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE resin) and the like.

  Examples of thermoplastic elastomers include polyester, polyamide, polyether, polyolefin, polyurethane, styrene, acrylic, polydiene, and the like. Among them, thermoplastic polyester elastomer Is preferred. Such thermoplastic polyester elastomers include both polyester-polyester type using polyester for hard segment and soft segment, and polyester-polyether type using polyester for hard segment and polyether for soft segment. It can be used suitably. In addition, although the hard segment of the polyester-type elastomer is generally used mainly with PBT or PBN, any thing can be used in this invention.

  In particular, among the above, PBT, PBN, PEN, PET, PC, PAR, and polyester resins such as polyester elastomer are preferable.

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

  Examples of the polymeric ion conductive agent are described in JP-A-9-227717, JP-A-10-120924, JP-A-2000-327922, JP-A-2005-60658, and the like. Although what can be used can be used, it is not specifically 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 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 polymeric ion conductive agents are 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 ion conductive agent in the present invention is readily available on the market as Pelestat 230, 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 is obtained. Sanconol TBX-310 (manufactured by Sanko Chemical Co., Ltd.) is commercially available.

  In the case where a polymer ion conductive agent is used as the conductive material, a compatibilizing agent may be added in order to enhance the compatibility between the base resin and the polymer ion conductive agent.

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

  The blending amount of the conductive material in each layer of the belt is usually 100 parts by weight or less, for example 1 to 100 parts by weight, particularly 1 to 80 parts by weight, especially 5 to 5 parts with respect to 100 parts by weight of the resin component. 50 parts by weight. Moreover, about an ion conductive agent, it is 0.01-10 weight part normally with respect to 100 weight part of resin components, Especially it is the range of 0.05-5 weight part. Furthermore, about a polymeric ion electrically conductive agent, it is 1-500 weight part normally with respect to 100 weight part of resin components, Preferably it is 10-400 weight part. In the present invention, it is particularly preferable to use carbon black as the conductive material and add it at 5 to 30 parts by weight with respect to 100 parts by weight of the resin component. In the present invention, the condition relating to the surface resistance value according to the present invention is satisfied by appropriately adjusting the blending amount of the conductive material in each layer within the above range. In particular, by imparting conductivity to the belt surface side layer to lower the surface resistance value, the difference from the surface resistance value on the base layer side can be made within a desired range.

  In addition to the above-mentioned components, other functional components can be appropriately added to each layer of the belt of the present invention as long as the effects of the present invention are not impaired. For example, various fillers and reinforcing materials Flame retardants, antioxidants, compatibilizers, coupling agents, antioxidants, lubricants, surface treatment agents, pigments, UV absorbers, antistatic agents, dispersants, neutralizing agents, foaming agents, crosslinking agents, etc. It can mix | blend suitably. Furthermore, you may color by adding a coloring agent.

  The belt of the present invention has a laminated structure including at least the base layer 101 and the surface layer 102, but may include other layers on the base layer-surface layer or the inner layer side of the base layer. As such another layer, for example, a layer having the same configuration as that of the outermost layer can be laminated on the inner layer side of the base layer. An adhesive layer may be provided between the base layer and the outermost layer. Note that the thickness of each layer can be appropriately determined depending on the function to be secured to each layer, the material to be used, and the like, and is not particularly limited. However, the base layer 101 is usually the thickest layer in the laminated structure.

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

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

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

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

  The conductive endless belt of the present invention can be preferably produced by coextrusion of each layer constituting the laminated structure. Specifically, for example, a biaxial kneader and a functional component such as a base material and a conductive material are used. It can manufacture by kneading the resin composition which consists of this, and extruding the obtained kneaded material using a cyclic die using a melt extruder. Alternatively, a powder coating method such as electrostatic coating, a dip method in which a surface layer material is dissolved in a solvent and applied to the base layer, or a centrifugal casting method in which each layer is multilayered by centrifugal molding can be suitably employed. Among them, the method by coextrusion without using a solvent is most preferable.

Hereinafter, the present invention will be described more specifically with reference to examples.
Conductive endless belts of Examples and Comparative Examples were prepared with the formulations shown in Tables 1 to 3 below. The compounding amounts in the following table all indicate parts by weight. Specifically, the blended components of each layer are melt-kneaded with a twin-screw kneader to be pelletized, and the pellets are melt-extruded with an extruder and then cut to obtain an inner diameter of 155 mm and a total thickness of 100 μm (base layer 85 μm). , Surface layer 15 μm), and a conductive endless belt having a width of 250 mm was obtained. As the die, a two-type two-layer annular die was used. The belts of the obtained examples and comparative examples were evaluated according to the following procedures. These results are also shown in Tables 1 to 3 below.

<Surface resistance value>
The surface resistance at 250 V of the obtained belt was measured using Hiresta (manufactured by Mitsubishi Chemical Corporation). The average value of the two measurement results was determined and used as the surface resistance value.

<Printing test>
The obtained belts were incorporated into a commercially available intermediate transfer printer, and the glossiness and ghost strength after printing 3000 sheets were evaluated. The glossiness was measured using a gloss meter (Horiba Seisakusho). A glossiness of 50 or higher is satisfactory without any problem. In addition, the evaluation of the ghost was performed by 10-step evaluation by visual observation. The case where no ghost was generated was 1 and the case where there were many ghosts was 10. The evaluation of the ghost is good with no problem if it is 3 or less.

＊１）ＰＢＴ：８００ＦＰ（ポリプラスチックス社製）
＊２）ＰＢＮ：ＴＱＢ−ＯＴ（帝人化成（株）製）
＊３）カーボンブラック：アセチレンブラック（電気化学工業（株）製）
＊４）ＴＰＥＥ：Ｅ−４５０Ｂ（東洋紡（株）製）

* 1) PBT: 800FP (manufactured by Polyplastics)
* 2) PBN: TQB-OT (manufactured by Teijin Chemicals Ltd.)
* 3) Carbon black: Acetylene black (manufactured by Denki Kagaku Kogyo Co., Ltd.)
* 4) TPEE: E-450B (manufactured by Toyobo Co., Ltd.)

＊５）難燃剤：ヒロマスターＦ１０１（鈴裕化学（株）製）

* 5) Flame retardant: Hiromaster F101 (manufactured by Suzuhiro Chemical Co., Ltd.)

  As shown in the above table, in the laminated belt, in the example in which the difference in surface resistance between the surface layer side and the base layer side was within 4 digits, the resistance was more resistant than the comparative example in which this difference was 5 digits or more. It was confirmed that good results were obtained for both glossiness and ghost strength after printing.

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 another intermediate transfer apparatus using an intermediate transfer member as another example of the image forming apparatus of the present invention.

Explanation of symbols

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

Claims (1)

In an endless belt-like conductive endless belt used in an image forming apparatus,
It has a laminated structure including at least a base layer and a surface layer sequentially from the inside, and the difference between the surface resistance value measured from the surface layer side and the surface resistance value measured from the base layer side is within 4 digits, Conductive endless belt.

Images