JP5137181B2 - Conductive endless belt - Google Patents

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, 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 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 the resin film belt, for example, Patent Document 1 discloses a conductive endless belt using a thermoplastic polyalkylene naphthalate resin, or a polymer alloy or a polymer blend of the thermoplastic polyalkylene naphthalate resin and another thermoplastic resin as a base material. It is disclosed. Patent Document 2 discloses a conductive seamless belt using a polyester elastomer having a melting point in a range of 160 ° C. to 210 ° C. as a conductive base layer.
JP 2002-132053 A (Claims etc.) Japanese Patent Laid-Open No. 2000-62993 (claims, etc.)

  However, in the belt disclosed in Patent Document 1, since the elastic modulus is high, elongation does not occur when the belt rotates, and thus image misalignment does not occur, but the bending resistance is not sufficient, and the belt durability is high. It was not enough. The belt disclosed in Patent Document 2 is excellent in durability because it uses an elastomer having a low melting point, but has a problem of image deterioration due to elongation and image deterioration due to deformation in a high temperature and high humidity environment. there were.

  Further, as a problem common to the belts according to these Patent Documents 1 and 2, in repeated use, the toner adheres when applied to an intermediate transfer type image forming apparatus, and the paper dust when applied to a tandem transfer type image forming apparatus. There is a problem that the glossiness of the belt surface is reduced due to the adhesion.

  Accordingly, an object of the present invention is to solve the above-mentioned problems and provide desired elastic modulus, bending resistance and durability, and there is no decrease in surface gloss due to adhesion of toner or paper powder, which is good even during long-term use. It is an object of the present invention to provide a conductive endless belt that can maintain high glossiness.

  As a result of intensive studies to solve the above problems, the inventor of the present invention uses a high-melting-point elastomer as a base material of the belt, and by adding a fluorine-based resin or a silicone-based compound thereto, the elastic modulus of the belt and The inventors have found that it is possible to improve creep properties and to impart toner releasability to the belt surface, thereby preventing a decrease in surface glossiness associated with use, and the present invention has been completed. It was.

In other words, 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,
Fluorine resin or silicone compound with respect to a substrate comprising a polyester elastomer having a crystal melting point of 210 ° C. or higher, or containing the polyester elastomer as a main component and containing a thermoplastic polyester resin at 49% by weight or less Is added.

Further, another conductive endless belt of the present invention is configured such that a recording medium held by electrostatic attraction is circulated and driven by a driving member and conveyed to a plurality of 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,
Fluorine resin or silicone compound with respect to a substrate comprising a polyester elastomer having a crystal melting point of 210 ° C. or higher, or containing the polyester elastomer as a main component and containing a thermoplastic polyester resin at 49% by weight or less Is added.

  In the belt of the present invention, the addition amount of the fluororesin or silicone compound is preferably in the range of 0.5 to 10 parts by weight with respect to 100 parts by weight of the base material.

  According to the present invention, the above-described configuration provides a desired elastic modulus, flex resistance and durability, and does not cause a decrease in surface gloss due to adhesion of toner or paper powder, and is good even during long-term use. It has become possible to realize a conductive endless belt capable of maintaining the glossiness.

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.

  The conductive endless belt of the present invention is made of a polyester elastomer having a crystal melting point of 210 ° C. or higher, preferably 210 to 250 ° C. or 49% by weight of a thermoplastic polyester resin containing the polyester elastomer as a main component. A fluororesin or a silicone compound is added to the base material contained below.

  In the present invention, by using such a high-melting polyester elastomer as a base material, it is possible to secure a high elastic modulus of the belt, to ensure excellent bending durability, and to improve creep resistance. In addition, by adding a fluororesin or a silicone compound as a surface property improver to this base material, it has become possible to improve the reduction in glossiness associated with use.

  In the present invention, the above-mentioned polyester elastomer can be used alone as a base material, but in addition to this, the thermoplastic polyester resin is preferably 49% by weight or less, particularly 20 to 40% by weight. Contain. By using a thermoplastic polyester resin together with the polyester elastomer, a belt with higher elasticity can be obtained. However, if the blending amount of the thermoplastic polyester resin exceeds 49% by weight, the bending resistance of the belt is lowered, and the desired effect of the present invention cannot be obtained.

  The polyester elastomer used in the present invention is not particularly limited as long as it satisfies a crystal melting point of 210 ° C. or higher. A polyester-polyester type using a polyester for the hard segment and the soft segment, and a polyester for the hard segment. Both polyester-polyether types using polyether as the soft segment can be preferably used. In addition, although the hard segment of the polyester-based elastomer is generally used mainly with polybutylene terephthalate (PBT) or polybutylene naphthalate (PBN), any one can be used in the present invention. .

  Specific examples of the thermoplastic polyester resin include thermoplastic polyalkylene naphthalate resins (for example, polyethylene naphthalate (PEN) resin, PBN resin, etc.), and thermoplastic polyalkylene terephthalate resins (for example, polyethylene). Terephthalate (PET) resin, glycol-modified PET (PETG) resin, PBT resin, etc.) can be mentioned, but is not particularly limited.

  In the present invention, the fluororesin added to the substrate is not particularly limited, but those having a low melting point of 250 ° C. or lower, particularly 240 ° C. or lower are preferable. For example, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), a copolymer of chlorotrifluoroethylene and ethylene (ECTFE), vinylidene fluoride (VDF) and tetra Examples thereof include a copolymer with fluoroethylene (TFE) and a terpolymer (THV) of tetrafluoroethylene, hexafluoropropylene (HFP) and vinylidene fluoride. The fluororesin is readily available on the market. For example, vinylidene fluoride-tetrafluoroethylene copolymer is manufactured by Daikin Industries, Ltd., trade name: NEOFLON VT100, etc., and THV is Sumitomo 3M Co., Ltd. ), Product names: Dionion THV220G, THV500G, and the like can be representatively mentioned. In addition, PTFE modified with a special acrylic resin can be suitably used in order to efficiently fibrillate PTFE and disperse it into the resin. For example, trade name: Metabrene A3000 manufactured by Mitsubishi Rayon Co., Ltd. And the like.

  The fluororesin may be used singly or in combination of two or more. Among them, PVdF and THV having a low melting point are particularly suitable and easily melt when kneaded simultaneously with other materials. The effect can be expressed. THV is a low-melting-point thermoplastic resin composed of three types of monomers: tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride. General-purpose fluorine such as heat resistance, chemical resistance, weather resistance, non-adhesiveness, and flame retardancy In addition to the features of the resin, it is a resin material that has excellent processability, solubility, crosslinkability, flexibility, adhesiveness, transparency and the like. In THV, the melting point can be changed by adjusting the monomer ratio.

  In the present invention, any silicone compound may be used as long as it is an organosilicon compound having a siloxane bond as a skeleton and an organic group or the like directly bonded to the silicon. Examples of the organic group include a methyl group, an ethyl group, a vinyl group, a phenyl group, and a trifluoropropyl group. In addition, a part of the organic group is substituted with a substituent having an amino group, an epoxy group, a carboxyl group, a mercapto group, a polyether group, an ester group, a chloroalkyl group, an alkyl group having 3 or more carbon atoms, a hydroxyl group, or the like. It may be.

  Silicone compounds are generally classified into silicone oils, silicone elastomers, and silicone resins based on the degree of crosslinking. These silicone compounds are described in, for example, “Silicone Material Handbook” (Toray Dow Corning Silicone Co., Ltd., issued in August 1993).

  In the present invention, any of the above-mentioned types of silicone compounds can be used, but silicone oils can be suitably used from the viewpoint of handleability and the like. Specific examples of the silicone oil include dimethyl silicone oil, phenylmethyl silicone oil, alkyl-modified silicone oil, fluorosilicone oil, polyether-modified silicone oil, aliphatic ester-modified silicone oil, amino-modified silicone oil, and carboxylic acid-modified silicone. Examples thereof include oil, carbinol-modified silicone oil, epoxy-modified silicone oil, and mercapto-modified silicone oil.

  The silicone oil used in the present invention preferably has a viscosity at 25 ° C. of 150,000 cSt or more, particularly 500,000 cSt or more.

  The silicone compound used in the present invention can be easily obtained in the form of a high-concentration masterbatch with various resins or a graft copolymer with various resins. Specific examples include silicone concentrate series manufactured by Toray Dow Corning Silicone Co., Ltd., sill graft series manufactured by Nihon Unicar Co., Ltd., and SP series manufactured by Dow Corning Asia Co., Ltd. Among these, from the viewpoint of compatibility with the base material, among silicone concentrates manufactured by Toray Dow Corning Silicone Co., Ltd., BY27-009 (PBT was used as a base resin to contain 50% by weight of silicone oil). Pellets), BY27-112 (a pellet containing 50% by weight of silicone oil using PET as a base resin), and the like can be suitably used.

  In the present invention, the addition amount of the fluorine-based resin or silicone-based compound is preferably in the range of 0.5 to 10 parts by weight with respect to 100 parts by weight of the base material. If the amount added is less than this range, the effect of preventing the decrease in surface glossiness may not be sufficient. On the other hand, if the amount exceeds this range, the belt surface appearance will be deteriorated.

  In addition, since the polyester-based elastomer and thermoplastic polyester resin used as the base material in the present invention have a drawback that they tend to cause a decrease in molecular weight due to hydrolysis during molding and heating, in particular, a compound having a carbodiimide group with respect to the base material. By adding, it is preferable to re-crosslink the thermoplastic polyester elastomer by the reaction between the carbodiimide group and the carboxylic acid to prevent a decrease in molecular weight. Thereby, embrittlement of the belt can be prevented, and the crack resistance of the belt at the time of durability can be improved. Such carbodiimide compounds are easily available on the market, and examples thereof include trade name: Carbodilite manufactured by Nisshinbo Industries, Inc. The carbodiimide compound can also be used in the form of a masterbatch pellet or the like, for example, Nisshinbo Co., Ltd. trade name: Carbodilite E pellet, B pellet or the like can be suitably used.

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

  Furthermore, a conductive agent is blended in the belt of the present invention in order to adjust conductivity. Such a conductive agent is not particularly limited, and a known electronic conductive agent, ionic conductive agent, or the like can be appropriately used.

  Of these, specific examples of the electronic conductive agent include conductive carbon such as ketjen black and acetylene black, carbon for rubber such as SAF, ISAF, HAF, FEF, GPF, SRF, FT, and MT, oxidation treatment, and the like. Colored (ink) carbon, natural graphite, artificial graphite, antimony-doped tin oxide, titanium oxide, zinc oxide, nickel, copper, silver, germanium and other metal and metal oxides, polyaniline, Conductive polymers such as polypyrrole and polyacetylene, carbon whisker, graphite whisker, titanium carbide whisker, conductive potassium titanate whisker, conductive barium titanate whisker, conductive titanium oxide whisker, conductive zinc oxide whisker, etc. Is mentioned. Specific examples of the ion conductive agent include perchlorates such as tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, benzyltrimethylammonium, modified fatty acid dimethylethylammonium, chlorate, Ammonium salts such as hydrochloride, bromate, iodate, borofluoride, sulfate, ethyl sulfate, carboxylate, sulfonate, alkali metals such as lithium, sodium, potassium, calcium, magnesium And alkaline earth metal perchlorates, chlorates, hydrochlorides, bromates, iodates, borofluorides, sulfates, trifluoromethyl sulfates, sulfonates, and the like.

  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 acid ester, polymethacrylic acid ester, polyacrylonitrile, polyvinyl alcohol, polyvinyl acetate, polyamide 6, polyamide 12, such as polyamide 12, 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 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 present invention, the conductive agent may be used alone or in combination of two or more, for example, an electronic conductive agent and an ionic conductive agent may be used in combination. In addition, it is possible to stably exhibit conductivity even when the applied voltage varies or the environment changes.

  In particular, among the above conductive agents, it is preferable to use carbon black, or it is preferable to use a polyether ester amide as a polymer ion conductive agent in combination with carbon black. In the latter case, by using two kinds of conductive agents in combination, it is possible to obtain a predetermined resistance with a small amount of addition, prevent a decrease in elastic modulus, and reduce resistance variation and environmental dependence. It can be a belt. Further, the polyether ester amide has a good compatibility with the polyester elastomer used as the base material in the belt of the present invention, and does not have a great adverse effect on the surface gloss and the bending resistance. The polyether ester amide is easily available on the market as, for example, Perestat NC6321 (manufactured by Sanyo Chemical Co., Ltd.).

  As the blending amount of the conductive agent, the electronic conductive agent is usually 100 parts by weight or less, for example 1 to 100 parts by weight, particularly 1 to 80 parts by weight, especially 5 to 50 parts by weight with respect to 100 parts by weight of the base material. It is. Moreover, about an ionic conductive agent, it is 0.01-10 weight part normally with respect to 100 weight part of base materials, Especially 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 base materials, Preferably it is 10-400 weight part. In particular, when carbon black is used alone as the conductive agent, the addition amount is preferably 5 to 30 parts by weight with respect to 100 parts by weight of the base material. Moreover, when using together polyetheresteramide and carbon black, the addition amount of polyetheresteramide is 5-25 weight part with respect to 100 weight part of base materials, and the addition amount of carbon black is 5-15 weight part. It can be.

  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.

  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 total thickness of the conductive endless belt of the present invention is appropriately selected according to the form of the transfer / conveying belt or the intermediate transfer member, but is preferably in the range of 50 to 200 μm. The surface roughness is preferably 10 μm or less, particularly 6 μm or less, more preferably 3 μm or less in terms of JIS 10-point average roughness Rz. Furthermore, 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 carried out.

  The conductive endless belt of the present invention can be suitably produced by extrusion molding of a resin composition containing the above-mentioned base material, fluororesin or silicone compound and a conductive agent. Specifically, for example, biaxial kneading It can be manufactured by kneading the resin composition containing the above-mentioned various blending components by a machine and extruding the obtained kneaded product using an annular die. Alternatively, a powder coating method such as electrostatic coating, a dip method, or a centrifugal casting method can also be suitably employed.

Hereinafter, the present invention will be described in more detail with reference to examples.
Conductive endless belts of Examples and Comparative Examples were prepared with the formulations shown in Tables 1 to 7 below. The compounding amounts in the following table all indicate parts by weight. Specifically, each compounding component is melt-kneaded with a twin-screw kneader, and the obtained kneaded product is extruded with an extruder using a predetermined annular die, thereby having dimensions of an inner diameter of 220 mm, a thickness of 100 μm, and a width of 250 mm. A conductive endless belt having The kneading / extrusion molding temperature was 250 ° C. in Examples 13 to 20 and Comparative Examples 6 and 7, and 240 ° C. in the other cases. 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 7 below.

<Measurement of tensile modulus>
The tensile modulus was measured under the following conditions.
Apparatus: Manufactured by Shimadzu Corporation, tensile tester EZ test (analysis software: Trappezium)
Sample: strip shape (length 100 mm x width 10 mm x standard thickness 100 μm)
Tensile speed: 5mm / sec
Data sampling interval: 100 msec
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)

<Folding resistance>
A test piece having a length of 100 mm and a width of 15 mm was cut out from each belt, and the bending speed was 175 times / min, the rotation angle was 135 degrees, and the tensile load was 14.7 N (using Toyo Seiki Co., Ltd.). The number of bending resistances was measured under the condition of 1.5 kgf). The results are shown as an index with Comparative Example 5 set to 4000. The higher the number, the better the result.

<Creep resistance>
A test piece having a length of 150 mm and a width of 10 mm was cut out from each belt, marked lines at intervals of 100 mm were written in the length direction, and a load of 200 g was applied in the length direction, at a temperature of 60 ° C. and a relative humidity of 85%. Left in the environment for 4 hours. The creep strain when the distance between marked lines before being left as L ₀ and the distance between marked lines after being left as L ₁ was determined according to the following formula. The evaluation results were ○ when the creep strain was 0.5% or less and × when the creep strain exceeded 0.5%. The distance between the marked lines was measured by leaving the test piece in an environment of a temperature of 23 ° C. and a relative humidity of 50% for one hour or more and then applying a load of 200 g in the length direction.
Creep strain (%) = {(L ₁ −L ₀ ) / L ₀ } × 100

<Measurement of volume resistance>
Measurement is performed at a voltage of 500 V using a resistance chamber R8340A connected to a sample chamber R12704A manufactured by ADVANTEST as a measuring device at a temperature of 23 ° C. and a relative humidity of 50%, and 20 mm in the circumferential direction. The average value of the values measured at 20 points on the pitch was determined.

<Glossiness>
After using the handy gloss meter IG-320 manufactured by Co., Ltd., each test belt as an intermediate transfer belt to an intermediate transfer type image forming apparatus and outputting 10,000 sheets of images The surface glossiness on the belt surface and the initial belt surface was measured.

＊１）ポリエステル系エラストマー：（１）ペルプレンＥ−４５０Ｂ，（２）ペルプレンＥＮ−１６０００，（３）ペルプレンＰ−９０Ｂ（いずれも東洋紡（株）製）
＊２）ＰＢＴ：（株）東レ製，トレコン１４０１ＣＨ２
＊３）ＰＢＮ：帝人化成（株）製，ＴＱＢ−ＯＴ
＊４）ＰＶｄＦ：ダイキン工業（株）製，ネオフロンＶＷ４１０
＊５）アクリル変性ＰＴＦＥ：三菱レイヨン（株），メタブレンＡ３０００
＊６）シリコーンマスターバッチ：東レ・ダウコーニング・シリコーン（株）製 シリコーンコンセントレートＢＹ２７−００９（ＰＢＴベース、シリコーンポリマー含有量５０重量％）
＊７）カルボジイミド化合物：日清紡績（株）製，カルボジライト
＊８）カーボンブラック：電気化学工業（株）製，デンカブラック粒状
＊９）ポリエーテルエステルアミド：三洋化成（株）製，ペレスタットＮＣ６３２１

* 1) Polyester elastomer: (1) Perprene E-450B, (2) Perprene EN-16000, (3) Perprene P-90B (both manufactured by Toyobo Co., Ltd.)
* 2) PBT: Toraycon 1401CH2 manufactured by Toray Industries, Inc.
* 3) PBN: Teijin Chemicals, TQB-OT
* 4) PVdF: Daikin Industries, Ltd., NEOFLON VW410
* 5) Acrylic modified PTFE: Mitsubishi Rayon Co., Ltd., Metabrene A3000
* 6) Silicone masterbatch: Silicone concentrate BY27-009 manufactured by Toray Dow Corning Silicone Co., Ltd. (PBT base, silicone polymer content 50% by weight)
* 7) Carbodiimide compound: Nisshinbo Co., Ltd., Carbodilite * 8) Carbon black: Denki Black granule, manufactured by Denki Kagaku Kogyo Co., Ltd. * 9) Polyetheresteramide: Sanyo Chemical Co., Ltd., Pelestat NC6321

  As shown in the above Tables 1 to 7, in the belts of the respective examples, the tensile elastic modulus, the number of bending resistances, the creep resistance, the volume resistance, and the initial and post-durability glossiness are all good. It turns out that the result is obtained. On the other hand, the belts of Comparative Examples 1 to 10 all have poor gloss after durability, and the belt of Comparative Example 3 cannot obtain a predetermined resistance value and cannot perform an image test. Comparative Examples 4 and 9 , 10 has insufficient creep resistance, Comparative Examples 5 and 8 have insufficient folding resistance, and Comparative Example 11 has a low glossiness after durability due to a small amount of fluororesin added. On the other hand, since Comparative Example 12 had a large amount of addition, the surface properties deteriorated and the glossiness deteriorated. As a result, none of the belt performances sufficiently satisfied the desired belt performance.

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. 10 is a schematic view showing an intermediate transfer device using another intermediate transfer member as still 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, 50 Intermediate transfer member 25 Transfer roller 26, 53 Recording medium 29, 61 Power supply 41, 42, 43, 44 Developer 54a-54d First developing section to fourth developing section 56 Recording medium feeding roller 57 Recording medium feeding apparatus 58 Fixing apparatus 59 Power supply apparatus (voltage applying means)

Claims (3)

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
Fluorine resin or silicone compound with respect to a substrate comprising a polyester elastomer having a crystal melting point of 210 ° C. or higher, or containing the polyester elastomer as a main component and containing a thermoplastic polyester resin at 49% by weight or less A conductive endless belt characterized by comprising: 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 a plurality of types of image forming bodies, and each toner image is sequentially transferred to the recording medium. In
Fluorine resin or silicone compound with respect to a substrate comprising a polyester elastomer having a crystal melting point of 210 ° C. or higher, or containing the polyester elastomer as a main component and containing a thermoplastic polyester resin at 49% by weight or less A conductive endless belt characterized by comprising:   The conductive endless belt according to claim 1 or 2, wherein the addition amount of the fluororesin or silicone compound is in the range of 0.5 to 10 parts by weight with respect to 100 parts by weight of the base material.

Images