JP2010169834A - Conductive endless belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer conductive endless belt having high durability, wherein peeling between layers, and wrinkles and cracks on a surface of a surface layer are suppressed. <P>SOLUTION: Disclosed is the conductive endless belt 100 that is an endless belt used in an image forming apparatus and has layered structure including a base layer 101, and the surface layer 102 in order from the inside, wherein tension rupture elongation of the surface layer 102 is larger than that of the base layer 101, and peeling strength of an adhesive surface between the base layer 101 and the surface layer 102 is 40(N/25 mm) or more. <P>COPYRIGHT: (C)2010,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 toner is supplied onto the photosensitive member to visualize the electrostatic latent image, the four colors of magenta, yellow, cyan, and black are sequentially added. There is a multi-development system in which development is performed by superimposing and a color toner image is formed on the photoreceptor. According to this method, it is possible to configure the apparatus relatively compactly, but this method has a problem in that it is very difficult to control gradation and high image quality cannot be obtained.

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

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

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

  On the other hand, in the case of a dielectric belt, there is no spontaneous release of injected charge, and both charge injection and discharge must be electrically controlled. However, since the charge is stably held, the sheet can be adsorbed reliably and can be conveyed with high accuracy. Since the dielectric constant is less dependent on temperature and humidity, the transfer process is relatively stable to the environment. The drawback is that the transfer voltage increases because charges are accumulated on the belt each time the transfer is repeated.

  Thirdly, a recording medium such as paper is wound around a transfer drum, and this is rotated four times, and magenta, yellow, cyan, and black on the photosensitive member are sequentially transferred to the recording medium every rotation to reproduce a color image. There is also a method. According to this method, a relatively high image quality can be obtained. However, when the recording medium is a cardboard such as a postcard, it is difficult to wind the recording medium around the transfer drum, and the type of the recording medium is limited. There is.

  A system in which good image quality is obtained with respect to the multiple development system, tandem system, and transfer drum system, the apparatus is not particularly large, and the type of recording medium is not particularly limited. As an example, an intermediate transfer method has been proposed.

  That is, in this intermediate transfer system, an intermediate transfer member composed of a drum or a belt for temporarily transferring and holding the toner image on the photosensitive member is provided, and a magenta toner image, a yellow toner image, and a cyan toner are provided around the intermediate transfer member. An image and four photoconductors on which a black toner image is formed are arranged, and four color toner images are sequentially transferred onto the intermediate transfer member, thereby forming a color image on the intermediate transfer member. The image is transferred onto a recording medium such as paper. Therefore, since the gradation is adjusted by superimposing the four color toner images, it is possible to obtain high image quality, and it is not necessary to arrange the photoconductors in a row as in the tandem method, so that the apparatus can be used. There is no particular increase in size, and there is no need to wrap the recording medium around the drum, so the type of recording medium is not limited.

  As an apparatus for forming a color image by the intermediate transfer method, an image forming apparatus using an endless belt-shaped intermediate transfer member as an intermediate transfer member is illustrated in FIG.

  In FIG. 3, reference numeral 11 denotes a drum-shaped photoconductor, which rotates in the direction of the arrow in the figure. The photosensitive member 11 is charged by the primary charger 12, and then the charged portion of the exposed portion is erased by image exposure 13, and an electrostatic latent image corresponding to the first color component is formed on the photosensitive member 11. The electrostatic latent image is developed with the first color magenta toner M by the developing device 41, and a first color magenta toner image is formed on the photoreceptor 11. Next, the toner image is circulated and driven by a driving roller (driving member) 30 and transferred to the intermediate transfer member 20 that circulates and rotates while contacting the photoreceptor 11. In this case, transfer from the photoconductor 11 to the intermediate transfer member 20 is performed by a primary transfer bias applied from the power source 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, a single layer belt such as an expensive polyimide single layer belt added with a conductive agent with high performance or a thermoplastic resin belt added with a conductive agent is used.

  Further, a multilayer belt is used as a transfer belt or the like as a resin film belt. In such a multilayer belt, the belt is wound around a tension roller such as a drive roller and curved, so that a surface layer in a curved portion of the belt is obtained. The outer side of the substrate is stretched so as to have a larger radius of curvature than the base layer side. Further, when the image is formed, such expansion and contraction of the surface layer is repeated, and wrinkles and cracks are generated on the surface of the surface layer with deterioration over time, which may adversely affect image characteristics.

  Therefore, in order to solve the above problems, Patent Document 1 discloses a technique for making the tensile breaking elongation on the surface layer side larger than the tensile breaking elongation on the base layer side.

JP 2001-166608 A (Claims etc.)

  Conventionally, a cartridge built-in transfer belt has been replaced with a new one when it reaches a certain number of copies, so durability is not necessary.However, in recent years, it is often attached to a printer body from the viewpoint of resource saving. Durability and environmental resistance higher than the printer body are required. Therefore, although the polyimide single-layer belt has high elasticity and high durability, the cost is high, and since a solvent is used during production, there is a problem in environmental resistance, and productivity is low. It is desired. Further, although the thermoplastic resin belt is excellent in mass productivity and cost, physical properties such as elastic modulus and durability are lower than those of the polyimide single-layer belt, and improvement thereof is desired.

  Further, the method described in Patent Document 1 has a problem that shearing force acts on the interface between the base layer and the surface layer when the belt is bent, and interface peeling occurs, and an improvement thereof is desired.

  Accordingly, an object of the present invention is to provide a multi-layered conductive endless belt having high durability that eliminates the above-described problems in the prior art and suppresses delamination between layers and wrinkles and cracks on the surface of the surface layer.

  As a result of intensive studies to solve the above problems, the present inventors have assigned functions to each layer of the multilayer belt, that is, the surface layer has functions such as surface property and toner releasability, and has elasticity, strength, durability. The inventors have found that the above problems can be solved by imparting mechanical properties such as property to the base layer, and have completed the present invention.

That is, the conductive endless belt of the present invention is an endless belt used in an image forming apparatus, and has a laminated structure including a base layer and a surface layer sequentially from the inside.
The tensile breaking elongation of the surface layer is larger than the tensile breaking elongation of the base layer,
The peel strength of the adhesive surface between the base layer and the surface layer is 40 (N / 25 mm) or more.

Further, in the conductive endless belt of the present invention, the base layer and the surface layer each contain a resin as a main material,
The difference in the compatibility parameter between the base layer resin and the surface layer resin is preferably 4.0 or less.

  Furthermore, in the conductive endless belt of the present invention, it is preferable that the base layer and the surface layer each have a tensile elastic modulus of 1500 MPa or more.

  According to the present invention, the above configuration makes it possible to realize a highly durable multi-layered conductive endless belt that suppresses delamination between layers and wrinkles and cracks on the surface of the surface layer.

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 image forming apparatus using a transfer conveyance belt as an example of an image forming apparatus. FIG. 6 is a schematic diagram illustrating an intermediate transfer device using an intermediate transfer member as another example of an image forming apparatus. FIG. 10 is a schematic diagram illustrating another intermediate transfer apparatus using an intermediate transfer member as still another example of the image forming apparatus. It is a graph which shows the relationship between the lifetime at the time of fatigue stress 20MPa, and peeling force. It is sectional drawing which shows a rotation durability tester.

Hereinafter, preferred embodiments of the present invention will be described in detail.
Generally, there are conductive endless belts with joints and belts without joints (so-called seamless belts), but any of them may be used in the present invention, and 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 is an endless belt used in an image forming apparatus, and has a laminated structure including a base layer 101 and a surface layer 102 sequentially from the inside.

  In the conductive endless belt 100 of the present invention, the tensile breaking elongation of the surface layer 102 is larger than the tensile breaking elongation of the base layer 101, and the value is not particularly limited as long as such a condition is satisfied. When bending is applied to the belt 100 at the roller portion, the surface layer 102 is likely to be cracked more easily than the base layer 101, and cracks are likely to occur. When cracks occur, image deterioration and noise increase occur. Life is shortened. Therefore, as in the present invention, by making the tensile break elongation of the surface layer 102 larger than the tensile break elongation of the base layer 101, the occurrence of cracks can be prevented and the life of the belt 100 can be extended. Here, the tensile breaking elongation of the surface layer 102 and the base layer 101 can be measured according to JIS K7161.

  Furthermore, in the conductive endless belt 100 of the present invention, the peel strength of the adhesive surface between the base layer 101 and the surface layer 102 is 40 (N / 25 mm) or more. FIG. 5 is a graph showing the relationship between the life and the peeling force when the fatigue stress is 20 MPa, and the horizontal axis shows the number of times N of life in logarithmic display (log N). As shown in FIG. 5, the lifetime can be 10,000 times or more by setting the peeling force to 40 (N / 25 mm) or more. Conventionally, a shearing force always acts on the interface between the base layer 101 and the surface layer 102 due to stretching force or bending at the roller portion, and the surface layer 102 is swollen or wrinkled when interface peeling occurs in an extremely severe environment. Furthermore, not only does the resistance value fluctuate and the image deteriorates, but it also becomes a stress concentration source and reduces the life of the belt 100. Thus, as in the present invention, by setting the peel strength in the T-type peel test to 40 (N / 25 mm) or more, the rotational life at a fatigue stress of 20 MPa required for the belt 100 is 10,000 times or more. be able to. In addition, the peeling strength of the adhesive surface of the base layer 101 and the surface layer 102 can be measured based on JIS K6854 (T-type peeling test).

  In the present invention, with the above structure, the surface layer 102 can have functions such as surface properties and toner releasability, and the base layer 101 can have mechanical properties such as elastic modulus, strength, and durability. A good adhesive force can be obtained between the layers 101, and peeling can be prevented even during repeated expansion and contraction at the curved portion of the belt 100. Further, when the belt 100 rotates, tensile strain repeatedly acts on the surface layer 102 side. However, by adopting the above configuration, the strain is absorbed by the surface layer 102 to suppress the occurrence of cracks, and the durability of the belt 100 as a whole. Can be increased.

  In the conductive endless belt of the present invention, the base layer 101 and the surface layer 102 each contain a resin as a main material, and the difference in the compatibility parameter between the resin of the base layer 101 and the resin of the surface layer 102 is 4.0 or less. It is preferable. By using the same material or the same type of material for the base layer 101 and the surface layer 102, the compatibility parameters are the same or close to each other. Therefore, the compatibility at the interface between the base layer 101 and the surface layer 102 is extremely high, and the melting points are almost the same. Therefore, the molecules are easily entangled with each other at the interface, and the adhesive force becomes very large. For example, the base layer 101 is a polyester alloy of PBT (polybutylene terephthalate) / TPEE (polyester elastomer), and the surface layer 102 is a combination of polyester resins such as PBT and PBN (polybutylene naphthalate). The case where it uses is mentioned.

Here, the compatibility parameter (SP) is the following equation:
It is calculated by SP = Σ (G) / molecular weight, G represents a molar pulling constant, and a value described in JP 2000-327813 A can be used.

  In the conductive endless belt of the present invention, the base layer 101 and the surface layer 102 preferably each have a tensile elastic modulus of 1500 MPa or more. Furthermore, it is preferable that the tensile strength of the base layer 101 and the surface layer 102 is 20 MPa or more, respectively. If the tensile modulus of elasticity of the base layer 101 and the surface layer 102 is 1500 MPa or less, there is a possibility that wavy wrinkles will be formed in the rotational direction of the belt due to the tension force, and the image may deteriorate, and the tensile strength of the base layer 101 and the surface layer 102 is If the pressure is 20 MPa or less, permanent deformation may occur due to the tension force and durability may be deteriorated. Furthermore, if the tensile elastic modulus of the surface layer 102 is 1500 MPa or less, the toner tends to sink into the belt surface layer 102 during the primary transfer, and the contact area may increase and the toner releasability in the secondary transfer may deteriorate. .

  As the resin of the surface layer 102 in the belt of the present invention, as a main component of the resin, a known thermoplastic resin or thermoplastic elastomer as a belt material is appropriately used alone or in combination of two or more kinds such as blends and alloys. It can be used and is not particularly limited.

  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 polyethylene terephthalate (PETG) resin, polybutylene terephthalate (PBT) resin), 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 polyaryle Preparative (PAR), thermoplastic polycarbonate (PC), polyethylene (PE), polypropylene (PP), polyphenylene sulfide (PPS), and polyolefin resins polyphenylene ether (PPE) or the like.

  Examples of the thermoplastic elastomer include various types such as polyester, polyamide, polyether, polyolefin, polyurethane, styrene, acrylic, and polydiene. Among them, thermoplastic polyester Elastomers are 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 addition, the base layer 101 in the belt of the present invention can be composed mainly of a thermoplastic resin and / or a thermoplastic elastomer. As such a thermoplastic resin, general-purpose resins can be used. For example, PBT, PBN, PEN, PET, PC, PA, POM, PAR, ABS, polyphenylene sulfide (PPS), polyphenylene ether (PPE), and the surface layer. Various thermoplastic elastomers as described above with respect to 102, blends and alloys thereof, and the like can be mentioned, but are not particularly limited.

  Further, in consideration of physical properties, moldability, cost, etc., PBT, PBN, PET, PEN, PC, PAR, etc. are suitable as the resin for the surface layer 102 and the base layer 101 in the belt of the present invention. Polyester elastomer and the like are preferable.

  In addition, since these polyester resins and polyester elastomers have a drawback of causing a decrease in molecular weight due to hydrolysis during molding and heating, in particular, by adding a compound having a carbodiimide group, a carbodiimide group and a carboxylic acid It is preferable to re-crosslink the polyester resin or the polyester-based elastomer by this reaction to prevent the molecular weight from being lowered. 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.

  Moreover, in order to adjust electroconductivity, each layer which comprises the belt of this invention can mix | blend a electrically conductive agent. 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.

Specific examples include a mixture of (A) an organic polymer material, (B) an ionically conductive polymer or copolymer, and (C) an inorganic or low molecular weight organic salt, wherein the 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 aromatic rings, and component (C) is inorganic or Alkali metal lower molecular weight organic protonic acid, an alkaline earth metal, zinc or ammonium salt, _{preferably, LiClO 4, LiCF 3 SO 3} , NaClO 4, LiBF 4, NaBF 4, KBF 4, NaCF 3 SO 3, KClO ₄ , KPF ₆ , KCF ₃ SO ₃ , KC ₄ F ₉ SO ₃ , Ca (ClO ₄ ) ₂ , Ca (PF ₆ ) ₂ , Mg (ClO ₄ ) ₂ , Mg (CF ₃ SO ₃ ) ₂ , Zn (ClO ₄ ) ₂ , Zn (PF ₆ ) _2, Ca (CF ₃ SO ₃ ) ₂ or the like.

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.

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

  These conductive agents 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. Conductivity can be expressed stably even with respect to voltage fluctuations and environmental changes.

  The blending amount of the conductive agent is usually 100 parts by mass or less, for example 1 to 100 parts by mass, particularly 1 to 80 parts by mass, especially 5 to 50 parts by mass with respect to 100 parts by mass of the resin component. . Moreover, about an ion conductive agent, it is 0.01-10 mass parts normally with respect to 100 mass parts of resin components, Especially it is the range of 0.05-5 mass parts. Furthermore, about a polymeric ion electrically conductive agent, it is about 1-500 mass parts normally with respect to 100 mass parts of resin components, Preferably it is about 10-400 mass parts. In the present invention, it is particularly preferable to add 5 to 30 parts by mass of carbon black as a conductive agent with respect to 100 parts by mass of the resin component.

  In addition to the above-described components, other functional components can be appropriately added to the belt of the present invention as long as the effects of the present invention are not impaired. For example, various kinds of fillers, reinforcing materials, A flame retardant, a coupling agent, an antioxidant, a lubricant, a surface treatment agent, a pigment, an ultraviolet absorber, an antistatic agent, a dispersant, a neutralizing agent, a foaming agent, a crosslinking agent, and the like can be appropriately blended. Furthermore, 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 inner layer side of the base layer. As such other layers, for example, a layer having the same configuration as the surface layer can be used by being laminated on the inner layer side of the base layer.

  The thickness of the surface layer 102 in the belt of the present invention is appropriately selected according to the material, but is preferably 2 to 50%, more preferably 2 to 20%, and even more preferably the total thickness of the belt. Preferably it occupies 5 to 15%.

  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, more preferably 80. Within the range of ~ 100 μm. The surface roughness is preferably 10 μm or less, particularly 6 μm or less, more preferably 3 μm or less in terms of JIS 10-point average roughness Rz.

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

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

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

  The conductive endless belt of the present invention can be preferably produced by coextrusion of each layer constituting the laminated structure, and in this case, the adhesiveness at the interface of each layer can be ensured well. Here, the co-extrusion is, for example, in the case of two layers, using two extruders for extruding the material for the base layer and the material for the surface layer, respectively, and one annular die for two layers. This is a method in which materials are simultaneously fed into an annular die, laminated in a die and extruded, and a laminated belt can be obtained in one step and in a short time. In the case of three or more layers, an extruder and a die corresponding to the number of layers may be used. In addition, by devising the flow path in the die, it is possible to stack more layers than the material type. By producing by coextrusion, no solvent is used during production, so the environmental resistance is good and the productivity is further increased. Furthermore, the belt of the present invention can be manufactured by a powder coating method such as electrostatic coating, a dip method, or a centrifugal molding method.

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 4 below. The compounding amounts in the following table all indicate parts by mass. Specifically, the blended components of each layer are melt-kneaded with a biaxial kneader, and the obtained kneaded product is extruded using a two-type two-layer cylindrical die, and has an inner diameter of 155 mm and a total thickness (Table 1 to Table 2). 4), and after cutting into a width of 250 mm, a meandering stop rib was attached to obtain a conductive endless belt.

  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 4 below.

<Measurement of tensile modulus>
The tensile modulus was measured under the following conditions.
Apparatus: A & D Corporation, Desktop Tensile Tester STA-1150
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)

<Tensile strength>
The maximum stress was measured under the same conditions as the tensile modulus measurement, and the tensile strength (MPa) was obtained.

<Tensile breaking elongation>
The elongation to break was measured under the same conditions as the tensile modulus measurement, and the elongation at break was determined.

<Peel strength>
Based on JIS K6854, the T-type peel strength (N / 25 mm) of the adhesion surface between the base layer and the surface layer was measured.

<Durability>
FIG. 6 is a cross-sectional view showing a rotational durability tester. A rotation endurance tester 60 capable of freely controlling the tension force 65 and the bending load force 64 with respect to the belt 63 between the two rollers 61 and 62 simulating an actual machine is manufactured, and the occurrence of cracks in the belt 63 is cracked. Detection was performed by the generation detector 66. Using such a rotation durability tester 60, the number of rotations (times) at which the belt 63 cracks was measured and determined as durability (times). Moreover, the number of rotations (times) was evaluated as good (◯) when the rotation was 10,000 times or more, and defective (×) when it was less than 10,000.

＊１）ＰＡ１２：３０２４Ｕ（宇部興産株式会社）
＊２）ＡＢＳ：テクノＡＢＳ２５（テクノポリマー株式会社）
＊３）ＰＶＤＦ（フッ化ビニリデン樹脂）：カイナーＡＤＸ（アルケマ株式会社）
＊４）ＰＢＴ１：６００ＦＰ（ポリプラスチックス株式会社）
＊５）ＴＰＥＥ：ＥＮ−５０００（東洋紡績株式会社）
＊６）ＰＢＮ：ＴＱＢ−ＯＴ（帝人化成株式会社）
＊７）ＰＥＴ：ＫＣ２５１（三菱レイヨン株式会社）
＊８）イオン導電剤Ａ：イルガスタットＰ１８（チバスペシャルティケミカルズ）
＊９）カーボンブラック：アセチレンブラック（電気化学工業株式会社）
＊１０）劣化防止剤：芳香族カルボジイミド（ラインケミー）
＊１１）難燃剤：ＴＢＢＡエポキシＳＲ−Ｔ３０４０（阪本薬品工業株式会社）＋四酸化アンチモン（山中産業株式会社）

* 1) PA12: 3024U (Ube Industries, Ltd.)
* 2) ABS: Techno ABS25 (Technopolymer Co., Ltd.)
* 3) PVDF (vinylidene fluoride resin): Kyner ADX (Arkema Corporation)
* 4) PBT1: 600FP (Polyplastics Corporation)
* 5) TPEE: EN-5000 (Toyobo Co., Ltd.)
* 6) PBN: TQB-OT (Teijin Chemicals Limited)
* 7) PET: KC251 (Mitsubishi Rayon Co., Ltd.)
* 8) Ionic conductive agent A: Irgastat P18 (Ciba Specialty Chemicals)
* 9) Carbon black: Acetylene black (Electrochemical Industry Co., Ltd.)
* 10) Deterioration inhibitor: Aromatic carbodiimide (Rhein Chemie)
* 11) Flame retardant: TBBA Epoxy SR-T3040 (Sakamoto Pharmaceutical Co., Ltd.) + Antimony Tetraoxide (Yamanaka Sangyo Co., Ltd.)

＊１２）ＰＭＭＡ（ポリメタクリル酸メチル）：アクリペット（三菱レイヨン株式会社）
＊１３）ＥＴＦＥ（熱可塑性フッ素樹脂）：ＡＨ−２０００（旭硝子株式会社）

* 12) PMMA (polymethyl methacrylate): Acrypet (Mitsubishi Rayon Co., Ltd.)
* 13) ETFE (thermoplastic fluororesin): AH-2000 (Asahi Glass Co., Ltd.)

＊１４）ＰＢＴ２：８００ＦＰ（ポリプラスチックス株式会社）

* 14) PBT2: 800FP (Polyplastics Corporation)

  As shown in Tables 1 to 4, in the belts of the examples, the tensile breaking elongation of the surface layer 102 is larger than the tensile breaking elongation of the base layer 101, and the peeling of the adhesive surface between the base layer 101 and the surface layer 102 is based on JIS K6854. Since the strength was 40 (N / 25 mm) or more, a highly durable multi-layered conductive endless belt that suppressed delamination between layers and wrinkles and cracks on the surface of the surface layer could be obtained. On the other hand, since the belts of Comparative Examples 1 to 5 are single layers, they do not satisfy the constituent requirements of the present invention. In particular, the belts of Comparative Examples 1 and 2 did not have sufficient durability. Moreover, since the peeling strength of the adhesive surface of the base layer 101 and the surface layer 102 was less than 40 (N / 25mm), the belts of Comparative Examples 6 to 9 could not obtain sufficient durability. Further, since the belts of Comparative Examples 6 to 8 use materials (ETFE, PVDF) and dissimilar materials (PMMA) having surface releasability as the surface layer, the properties of compatibility, viscosity, melting point, etc. are the base layer resins. Therefore, the adhesion tends to deteriorate. Therefore, reducing the addition of a material with poor adhesion improves the adhesion between the adhesion surfaces of the base layer 101 and the surface layer 102. For example, in Comparative Example 9, the peel strength is 35 (N / 25 mm) because PVDF is 30 parts by mass. On the other hand, in Example 1, since it was 10 parts by mass of PVDF, a favorable result of 50 (N / 25 mm) was obtained. Furthermore, since the tensile break elongation of the surface layer 102 was smaller than the tensile break elongation of the base layer 101, the belts of Comparative Examples 10 to 12 could not obtain sufficient durability.

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)
60 Rotational endurance tester 61, 62 Roller 63 Belt 64 Bending load force 65 Tension force 66 Crack occurrence detector 100 Conductive endless belt 101 Base layer 102 Surface layer

Claims (3)

In a conductive endless belt having an endless belt shape used for an image forming apparatus and having a laminated structure including a base layer and a surface layer sequentially from the inside,
The tensile breaking elongation of the surface layer is larger than the tensile breaking elongation of the base layer,
A conductive endless belt, wherein a peel strength of an adhesive surface between the base layer and the surface layer is 40 (N / 25 mm) or more. The base layer and the surface layer each contain a resin as a main material,
The conductive endless belt according to claim 1, wherein a difference in compatibility parameter between the resin of the base layer and the resin of the surface layer is 4.0 or less.   The conductive endless belt according to claim 1 or 2, wherein the base layer and the surface layer each have a tensile elastic modulus of 1500 MPa or more.

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