JP4845994B2 - Belt and image forming apparatus having the same - Google Patents

Description

  The present invention relates to a belt and an image forming apparatus including the belt, and more particularly to a meandering prevention member provided on an inner peripheral surface of an endless belt.

  In an image forming apparatus such as a conventional electrophotographic apparatus, an endless belt is used as a belt-like photoreceptor, an intermediate transfer belt, a transfer belt, a paper conveyance belt, a fixing belt, or the like.

  Here, such an endless belt is generally supported by two or more rollers and is driven to rotate while being given an arbitrary tension. The straightness or roundness of the supporting rollers depends on the axis of each roller. The parallelism of the belt and the roundness of the endless belt itself have slight errors and variations, and therefore may meander to the left and right during rotational driving. When such an endless belt is used as a transfer belt for a full-color electrophotographic apparatus or the like where accuracy is required, the image forming position of each color shifts when the color is superimposed on the transfer belt due to the meandering of the transfer belt. Deviation occurs.

  Therefore, in order to prevent such meandering, a meandering prevention member is provided on the entire inner circumference of the transfer belt, and a groove is provided on a roller on which the transfer belt is stretched, and the meandering prevention member is locked in this groove. By rotating the roller while rotating, the transfer belt can be smoothly run without meandering, whereby a good image without color misregistration can be formed.

  However, in the transfer belt having this configuration, the meandering prevention member may be peeled off from the transfer belt due to the stress caused by the deformation of the meandering prevention member by a roller or the like, or the transfer belt may be cracked in some cases. For this reason, for example, an acrylic foam is used as a belt reinforcing base material, and a polyurethane sheet having a prescribed hardness is adhered thereon, thereby providing a meandering prevention effect and a stress relaxation effect on the belt (Patent Literature). 1).

Japanese Patent Laid-Open No. 08-099706

  However, in such a configuration, since the non-foam occupies most of the thickness of the meandering prevention member, the meandering prevention member is greatly deformed at the belt bending portion and receives a great deal of stress. The meandering-preventing member may peel off.

  This phenomenon is particularly remarkable when the diameter of the roller that stretches the transfer belt is small and the winding angle of the transfer belt with respect to the roller is large. In other words, in order to meet the life of the transfer belt, it is necessary to increase the diameter of the roller that stretches the transfer belt and reduce the winding angle of the transfer belt around the roller, that is, to make the roller multi-axial. This is a great barrier to downsizing the image forming apparatus.

  Therefore, the present invention has been made in view of such a situation, and an object thereof is to provide a belt having a long durability life and an image forming apparatus including the belt.

The present invention has an endless belt body and a meandering prevention member provided on an inner peripheral surface of the belt body, the belt body is stretched by a tension member, and the belt body and the meandering prevention member Is movable, and the meander-preventing member is a belt that restricts movement in a direction perpendicular to the moving direction of the belt main body and the meander-preventing member when the meander-preventing member contacts the tension member, is formed of foam, wherein the foam has a second bubble-generating region having voids at a rate porosity is lower than the first foam area with the first foam area, before Symbol foam the The region bonded to the inner peripheral surface of the belt main body is the second foaming region.

  As in the present invention, by forming the entire meandering prevention member provided on the inner peripheral surface of the endless belt body with a foam, it is possible to prevent peeling of the meandering prevention member and damage to the belt. A belt having a long durability life can be obtained. Further, by forming the whole meandering prevention member from foam, it is possible to prevent peeling of the meandering prevention member and damage to the belt even when the diameter of the roller for stretching the belt is small and the winding angle is large. Thus, the image forming apparatus can be reduced in size.

1 is a diagram illustrating a schematic configuration of an image forming apparatus using an intermediate transfer belt which is an example of a belt according to an embodiment of the present invention. 1 is a diagram illustrating a schematic configuration of an image forming apparatus using a transfer conveyance belt which is an example of a belt according to an embodiment of the present invention. The figure which shows the structure of the said belt (intermediate transfer belt and transfer conveyance belt). FIG. 4 is a diagram illustrating a method for obtaining a color shift in the belt (intermediate transfer belt and transfer conveyance belt). The figure which shows the winding angle to the roller of the said belt (intermediate transfer belt and transfer conveyance belt).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a laser color printer (image forming apparatus) using an intermediate transfer belt which is an example of a belt according to an embodiment of the present invention.

  In the figure, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) as a first image bearing member, which is driven to rotate at a predetermined peripheral speed (process speed) in the direction of an arrow. It has become.

  Reference numeral 2 denotes a corona charger that uniformly charges the surface of the photosensitive drum 1 to a predetermined polarity and potential, and reference numerals 41 to 44 denote static images formed on the photosensitive drum by receiving exposure 3 by an image exposure unit (not shown). The developing unit develops the electrostatic latent image with toners of M (magenta), C (cyan), Y (yellow), and B (black). The image exposure means includes a color separation / imaging exposure optical system for a color document, a scanning exposure optical system using a laser scanner that outputs a laser beam modulated in accordance with a time-series electric digital pixel signal of image information, and the like. use.

  Reference numeral 6 denotes an intermediate transfer belt, and reference numeral 8 denotes a primary transfer roller that rotates while pressing the intermediate transfer belt 6 against the photosensitive drum 1. The toner image formed and supported on the photosensitive drum 1 is transferred to the intermediate transfer belt 6 by the photosensitive drum 1. Is transferred onto the outer peripheral surface of the intermediate transfer belt 6 by an electric field and pressure formed by a primary transfer bias having a polarity opposite to that of the toner applied from the power supply 15 to the primary transfer roller 8 in the process of passing while pressing against the intermediate transfer belt 6. It has come to be.

  The intermediate transfer belt 6 is stretched around a drive roller 9, a tension roller 10, a secondary transfer counter roller 11, and a primary transfer roller 8, and is driven to rotate at a predetermined peripheral speed in the direction of an arrow by the drive roller 9. It has come to be.

  Reference numeral 12 denotes a secondary transfer roller that contacts the intermediate transfer belt 6. A full-color image transferred onto the intermediate transfer belt 6 is fed by a pickup roller 13a or the like from the paper feed cassette 14 at a predetermined timing. When the transfer material 13, which is the carrier of No. 2, passes through the contact nip between the intermediate transfer belt 6 and the secondary transfer roller 12, the transfer material 13 is transferred by the secondary transfer bias applied to the secondary transfer roller 12 from the bias power supply 16. The material 13 is transferred.

  Reference numeral 17 denotes a fixing device that heats and fixes the transferred toner image on the transfer material 13, and reference numeral 7 denotes an intermediate transfer belt cleaning member that cleans transfer residual toner on the intermediate transfer belt 6 after image transfer to the transfer material 13. Reference numeral 5 denotes a cleaning member for the photosensitive drum 1.

  Next, an image forming operation of the image forming apparatus having such a configuration will be described.

  When forming an image, first, the surface of the photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by the corona charger 2 during the rotation of the photosensitive drum 1. Next, an electrostatic latent image corresponding to a first color component (for example, a magenta component image) of a target color image is formed on the surface of the photosensitive drum 1 by exposure 3 from an image exposure unit (not shown).

  Next, the electrostatic latent image is developed by a first developing device 41 (magenta developing device), and then the first color magenta toner image formed and supported on the photosensitive drum 1 is moved in the direction of the arrow. A primary transfer is applied to the primary transfer roller 8 from the power supply 15 on the outer peripheral surface of the intermediate transfer belt 6 which is rotationally driven while being pressed against the photosensitive drum 1 at a predetermined peripheral speed.

  Similarly, the second color cyan toner image, the third color yellow toner image, and the fourth color black toner image are successively superimposed and transferred onto the intermediate transfer belt 6 to form a target full color image. In this primary transfer process, the secondary transfer roller 12 and the intermediate transfer belt cleaning member 7 are separated from the intermediate transfer belt 6.

  Next, the full color image superimposed and transferred on the intermediate transfer belt 6 is fed from the paper feed cassette 14 at a predetermined timing, and passes through a contact nip between the intermediate transfer belt 6 and the secondary transfer roller 12. At this time, the image is transferred to the secondary transfer roller 12 already in contact with the intermediate transfer belt 6 by the secondary transfer bias applied from the bias power supply 16.

  Then, the transfer material 13 on which the toner image is secondarily transferred in this way is introduced into the fixing device 17, and the toner image is heated and fixed on the transfer material 13 in the fixing device 17. After the image transfer to the transfer material 13, the transfer residual toner on the intermediate transfer belt 6 is removed by the intermediate transfer belt cleaning member 7 already in contact with the intermediate transfer belt 6 at this time.

  On the other hand, FIG. 2 is a diagram showing a schematic configuration of an image forming apparatus using a transfer conveyance belt which is an example of a belt according to an embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts. The image forming apparatus is a tandem laser color printer in which image forming stations of a plurality of colors (for example, yellow, magenta, cyan, and black) are arranged.

  In the figure, 20Y, 20M, 20C, and 20K are first to fourth image forming stations, and these image forming stations 20Y, 20M, 20C, and 20K each have a predetermined peripheral speed (process speed) in the direction of an arrow. Photosensitive drums 1Y, 1M, 1C, and 1K, and primary charging rollers 2Y, 2M, 2C, and 2K that uniformly charge the surfaces of the photosensitive drums 1Y, 1M, 1C, and 1K to a predetermined polarity and potential. And developing units 4Y, 4Y for developing electrostatic latent images formed on the photosensitive drum by receiving exposures 3Y, 3M, 3C, 3K by image exposure means (not shown) with M, C, Y, B toners, respectively. 4M, 4C, 4K.

  Reference numeral 61 denotes a transfer conveyance belt that is stretched around the drive roller 9 and the driven roller 91, and is rotationally driven by the drive roller 9 in the direction of the arrow at a predetermined peripheral speed, and 8Y, 8M, 8C, and 8K are transfer sheets. The toner image formed and supported on the photosensitive drums 1Y, 1M, 1C, and 1K is supplied to the bias power source 15Y in the process in which the transfer material 13 passes through the nip portion between the photosensitive drums 1Y, 1M, 1C, and 1K and the transfer conveyance belt 61. , 15M, 15C and 15K are transferred onto the transfer material 13 by a transfer bias applied to the transfer sheets 8Y, 8M, 8C and 8K.

  Reference numeral 18 denotes an attracting roller for applying a predetermined attracting bias to the attracting roller 18 for attracting the transfer material 13 to the transfer / conveying belt 61, and 19 is a separation for separating the transfer material 13 from the transfer / conveying belt 61. A separation charger that applies a bias.

  Next, an image forming operation of the image forming apparatus having such a configuration will be described.

  When forming an image, first, as a charging process, the surface of the photosensitive drum 1Y of the first image forming station 20Y is uniformly charged to a predetermined polarity and potential by the primary charging roller 2Y during the rotation of the photosensitive drum 1Y. Next, an electrostatic latent image corresponding to the first color component (yellow) of the target color image is formed on the surface of the photosensitive drum 1Y by exposure 3Y from an image exposure means (not shown) as an exposure process.

  Next, the electrostatic latent image is developed by the first developing device 4Y (yellow developing device) as a developing process. Thereafter, as a transfer process, the yellow toner image of the first color formed and supported on the photosensitive drum 1Y is fed from the paper feed cassette 14 at a predetermined timing, and then is predetermined by the drive roller 9 in the direction of the arrow. When the transfer material 13 that is carried and moved by the transfer conveyance belt 61 rotated at a peripheral speed passes through the contact nip between the transfer conveyance belt 61 and the photosensitive drum 1Y, the transfer material 13 is supplied with a bias power source. The image is electrostatically transferred by a transfer bias applied from 15Y to the transfer sheet 8Y. If necessary, a predetermined suction bias is applied to the suction roller 18 in order to suck the transfer material 13 to the transfer conveyance belt 61.

  Next, the residual toner that has not been transferred from the photosensitive drum 1Y onto the transfer material 13 as a cleaning process is removed by the photosensitive drum cleaner 5Y. Thereafter, the image forming steps of charging, exposure, development, transfer and cleaning are repeated.

  Further, in the second to fourth image forming stations 20M, 20C, and 20K, yellow, magenta, cyan, and black are formed on the transfer material 13 by performing the same image forming process as the first image forming station 20Y at a predetermined timing. The toner is superimposed and transferred to form a desired full-color image.

  Thereafter, the transfer material 13 onto which the toner image has been transferred is separated from the transfer conveyance belt 61 and then introduced into the fixing device 17, where the toner image is heated and fixed to the transfer material 13. Further, after the image transfer to the transfer material 13 is completed, the paper dust, toner and the like on the transfer conveyance belt 61 are removed by the belt cleaning member 71. Note that the separation charger 19 may be used when the transfer material 13 is separated from the transfer conveyance belt 61.

  By the way, the intermediate transfer belt 6 and the transfer / conveying belt 61 (hereinafter referred to as the intermediate transfer belt 6 and the like), which are belts that require accuracy with respect to meandering, are arranged on the outer peripheral surface as shown in FIGS. It has endless belt bodies 6a and 61a to which toner images are transferred, and meandering prevention members 6b and 61b provided at one or both ends of the inner peripheral surfaces of the belt bodies 6a and 61a.

  However, since the intermediate transfer belt 6 and the like are driven to rotate by being stretched around two or more rollers (see FIGS. 1 and 2), the above-described meandering prevention members 6b and 61b are simply disposed. As described above, the meandering prevention members 6b and 61b are peeled off from the belt main bodies 6a and 61a due to the stress caused by the deformation of the meandering prevention members 6b and 61b at the roller portion, and in some cases, the belt main bodies 6a and 61a are cracked.

  Therefore, in the present embodiment, a foam is used as the meandering preventing members 6b and 61b. And by using a foam in this way, the meandering prevention members 6b and 61b can follow the deformation | transformation in a roller part etc. now. Thereby, the stress applied to the meandering prevention members 6b and 61b can be reduced, and the meandering prevention members 6b and 61b can be prevented from being peeled off from the belt main bodies 6a and 61a and the belt main bodies 6a and 61a can be damaged. .

  Here, the average foam diameter of the foam is preferably 10 μm or more and 300 μm or less. When the average foam diameter is less than 10 μm, the meandering prevention members 6b and 61b are less likely to follow the deformation, so that peeling from the belt bodies 6a and 61a is likely to occur, and the average foam diameter exceeds 300 μm. In such a case, since the straightness of the meandering prevention members 6b and 61b is lowered, the meandering prevention effect may be reduced.

  The porosity of the foam is preferably 20% or more and 80% or less. When the porosity is less than 20%, the meander prevention members 6b and 61b are less likely to follow the deformation, and therefore the peeling from the belt bodies 6a and 61a is likely to occur, and exceeds 80%. In some cases, the rigidity of the meandering prevention members 6b and 61b is lowered, and the meandering prevention effect may be lowered.

  Further, at least one of the surface where the meandering prevention members 6b and 61b and the belt main bodies 6a and 61a are joined and the surface where the meandering prevention members 6b and 61b and the roller member are in contact, that is, the foam belt main bodies 6a and 61a are joined. At least one of the surface to be touched and the surface in contact with the roller preferably has skin layers 6c and 61c which are surface layers whose porosity is clearly lower than other portions as shown in FIG. 3B. .

  And by having such skin layers 6c and 61c, it becomes possible to increase the joining strength when joining the meandering preventing members 6b and 61b and the belt bodies 6a and 61a (adhesion, adhesion, etc.). Further, the slidability between the meandering preventing members 6b and 61b and the roller is improved, and the meandering preventing effect is enhanced.

  Here, such an effect is remarkably exhibited when the porosity of the skin layers 6c and 61c is less than 20%. Moreover, it is preferable that the thickness of the skin layers 6c and 61c is 100 micrometers or less. If the skin layer exceeds 100 μm, the flexibility of the meandering preventing members 6b and 61b is reduced and it becomes difficult to follow the deformation, so that peeling from the belt main bodies 6a and 61a is likely to occur.

  Moreover, it is preferable that the belt main bodies 6a and 61a having the meandering preventing members 6b and 61b are seamless belts having no joints. And since it becomes possible to reduce film thickness non-uniformity by having no joints in this way, and the concentration of stress on the belt main bodies 6a and 61a due to bending at the roller portion can be suppressed, the belt main bodies 6a, The lifetime of 61a can be further increased.

  By the way, the material of the foam constituting the meandering preventing members 6b and 61b is not particularly limited, and a known foam can be used. However, the belt main body 6a with various adhesives and adhesives has a small compression set. , 61a, urethane foam and acrylic foam are preferable.

  Further, the cross-sectional shape of the meandering preventing members 6b and 61b is such that the meandering preventing groove R1 formed on the outer peripheral surface of the roller R on which the intermediate transfer belt 6 is stretched as shown in FIG. In general, the cross-sectional shape is square or rectangular for reasons such as ease of processing. Specifically, a square or rectangular cross-sectional shape having a width of 1 to 5 mm and a thickness of 0.3 to 0.5 mm is preferable, but is not limited to this range.

  In the present embodiment, the case where the meandering prevention members 6b and 61b are locked in the meandering prevention groove R1 formed on the outer peripheral surface of the roller R is described. However, the meandering prevention members 6b and 61b are illustrated in FIG. As shown in FIG. 3 (d), the roller R may be engaged with the side end. Even in such a case, it is preferable that the cross-sectional shape of the meandering preventing members 6b and 61b is as described above.

  On the other hand, the flexible belt main bodies 6a and 61a are not particularly limited as long as they have a belt shape, such as a film shape or a mesh shape. Examples of the material include those made of various materials such as a thermosetting resin, a thermoplastic resin, a metal and a rubber, and the thermoplastic resin is particularly preferable from the viewpoint of ease of molding and cost. Those consisting of are preferred.

  Specifically, polyethylene (high density, medium density, low density, linear low density, etc.), polypropylene, polystyrene, ethylene-vinyl alcohol copolymer (EVOH), polycarbonate, polyamide, polyacetal, polyarylate, polyphenylene ether , Modified polyphenylene ether, polyimide, liquid crystalline polymer, polysulfone, polyether sulfone, polyphenylene sulfite, polybisamide triazole, polyether imide, polyamide imide, polyether ether ketone, aliphatic polyketone, polymethylpentene, polybutylene terephthalate, Polyethylene terephthalate, polyethylene naphthalate, polyvinyl fluoride, polyvinylidene fluoride (PVdF), chlorotrifluoroethylene, ethylene tetrafluoride Emissions copolymer (ETFE), hexafluoropropylene, perfluoroalkyl vinyl ether copolymer, it is possible to use a methacrylic resin, one kind or two kinds or more selected from such various other copolymers.

  In particular, but not limited to these, polycarbonate, polyvinylidene fluoride (PVdF), polysulfone, polyimide, polyphenylene sulfide, polyarylate, ethylene tetrafluoride ethylene copolymer in consideration of the mechanical properties and moldability of the belt Combined (ETFE) is preferred.

  For the purpose of imparting conductivity to these resins, various conductive agents such as carbon black such as acetylene black, furnace black and channel black, titanium oxide, potassium titanate, tin oxide, lithium salt, quaternary ammonium salt and the like. May be added.

  Furthermore, fillers such as talc, mica and calcium carbonate, flame retardants such as magnesium hydroxide and antimony trioxide, and additives such as antioxidants (phenolic and sulfur based) may be added. Of course, the additive is not limited to the above-mentioned substances, and any other additive can be used.

  Here, as a method of adding an additive to the resin, after premixing, a method of kneading and dispersing using a known kneader such as a single screw extruder, a twin screw extruder, a Banbury mixer, a roller, or a kneader Is mentioned. Normally, each component is kneaded in an extruder or the like to form a beret-like compound and then molded, but in special cases, each component is directly supplied to the molding machine and the composition is kneaded with the molding machine. It can also be molded.

  On the other hand, as a manufacturing method of the belt main bodies 6a and 61a, known methods such as a centrifugal molding method, a continuous melt extrusion method, an injection molding method or a blow molding method, and an inflation film molding method can be adopted. The molding method or the inflation molding method is preferable because it can be manufactured at low cost. The endless belt molded in this manner may be subjected to operations such as stretching.

  Here, the thickness of the belt bodies 6a and 61a is preferably 50 μm or more and 1000 μm or less, and more preferably 100 μm or more and 700 μm or less. If the thickness is less than 50 μm, the belt bodies 6a and 61a tend to be stretched. If the thickness exceeds 1000 μm, flexible deformation becomes difficult, and a uniform speed cannot be driven by the small-diameter roller. Arise.

  Furthermore, the belt bodies 6a and 61a may be composed of a single layer or may be composed of a plurality of layers. Moreover, when obtaining the belt main bodies 6a and 61a consisting of a plurality of layers, a thermoplastic resin member formed in advance with a plurality of layers may be obtained by extrusion from a multilayer die, or a single layer from a single layer thermoplastic resin member. To obtain a belt body 6a, 61a composed of a plurality of layers by providing a new layer on the front or back surface of the single-layer endless belt by spraying, for example, paint or the like, and dipping. It may be.

  On the other hand, the joining method of the meandering preventing members 6b and 61b and the belt main bodies 6a and 61a is not particularly limited and can be joined by a known joining (adhesion or adhesion) method. It is preferable to use a double-sided tape having an acrylic adhesive.

  Further, for the purpose of reinforcing or improving the joining strength between the belt main bodies 6a and 61a and the meandering preventing members 6b and 61b, a belt-like member (not shown) may be provided at the end of the belt main bodies 6a and 61a. Various materials can be used as the material of the belt-like member, and PET (polyethylene terephthalate) tape is preferable from the viewpoint of the effect of reinforcing the belt and ease of handling.

  Furthermore, various surface treatments such as corona treatment can be applied to the joint surfaces of the meandering prevention members 6b and 61b and the belt bodies 6a and 61a for the purpose of improving the joining strength between the belt bodies 6a and 61a and the meandering prevention members 6b and 61b. It is.

  Next, a method for measuring the average foam diameter and porosity of the foam will be described.

  When performing the measurement, first, the meandering prevention members 6b and 61b are cut at an arbitrary position using a sharp blade (such as a razor) so as not to crush the foam (cell).

Next, it is enlarged using a microscope (optical microscope, scanning electron condyle microscope, etc.), the number of cells N per arbitrary measurement range S (μm ² ) is counted, and the diameter R (μm) of each cell is counted. taking measurement. Here, when the shape of the cell is indefinite, the outer periphery of the cell is measured, and a circle and a cell having the same outer periphery as the actually measured external station are assumed to be the cell diameter. Conditions for easy measurement can be selected for the enlargement magnification and the measurement range in consideration of the cell size and the like, but the measurement range is set so that the number of cells to be counted is 50 or more.

なお、Ｒ_１〜Ｒ_Ｎ：カウントしたセルのそれぞれの直径（μｍ）

R _{1 to} R _N : Diameter of each counted cell (μm)

また、スキン層の空隙率の測定は、スキン層表面の任意の１ｍｍ四方中に存在するセル数とその平均発泡径から上記の式より求める。なお、その厚みは上記のようにして切断した発泡体断面を顕微鏡（光学顕微鏡、走査電子顕微鏡等）を使用し、拡大して計測する。

Moreover, the measurement of the porosity of a skin layer is calculated | required from said formula from the number of cells which exist in the arbitrary 1 mm squares of the skin layer surface, and its average foam diameter. The thickness is measured by enlarging the foam cross section cut as described above using a microscope (such as an optical microscope or a scanning electron microscope).

  Next, examples of the present embodiment will be described.

Example 1
<Production of endless belt>
Three kinds of materials are blended as follows.

Polycarbonate resin 100 parts by weight Carbon black 15 parts by weight Antioxidant 0.5 part by weight Three types of materials blended as described above are kneaded in a biaxial extrusion kneader, and additives such as carbon black are sufficiently contained in the binder. Were uniformly dispersed to obtain a raw material for molding. Further, this was made into a kneaded product having a particle diameter of 1 to 2 mm, and then charged into a hopper of a single screw extruder, and adjusted to a temperature of 270 to 290 ° C. and extruded to obtain a melt.

  Next, this melt was introduced into a cylindrical single-layer extrusion die having a diameter of 100 mm and a die gap of 900 μm, and then expanded by blowing air from an air introduction path, resulting in a final shape of 140 mm in diameter and 150 μm in thickness. did. Further, the belt was cut at a width of 250 mm to obtain a seamless belt.

  On the other hand, a reinforcing tape made of polyethylene terephthalate resin was used as the reinforcing member and adhered to both end portions of the inner peripheral surface of the seamless belt to obtain a seamless belt having the reinforcing member on the inner peripheral surface.

<Join the meandering prevention member to the endless belt>
Next, a polyurethane foam having a rectangular cross-section of 2 mm in thickness and 3 mm in width on the inner peripheral surface of the reinforcing member of the seamless belt thus obtained and having a skin layer on four sides of the cross-section is an acrylic pressure-sensitive adhesive. An endless belt having a meandering-preventing member was obtained by sticking with a double-sided tape having Here, the thickness of the skin layer was about 3 μm, and the porosity of the skin layer was 10%. The average foam diameter of the foam was 50 μm, and the porosity of the foam was 50%.

  The endless belt having the meander-preventing member thus obtained is incorporated as an intermediate transfer belt 6 of the color laser printer having the configuration shown in FIG. 1, and the endurance of 10,000 full-color sheets corresponding to 40,000 revolutions of the intermediate transfer belt 6 is achieved. A test was conducted. As a result, problems such as peeling of the meandering preventing member and cracks and chippings at the belt end did not occur, and the durability was sufficient. Also, the amount of color misregistration was as good as about 50 μm on average.

  Note that the average value of the color misregistration amount is obtained by outputting a line image (image having a line width of 200 μm or less) as shown in FIG. Was determined by

  Furthermore, when the joining strength of the meandering prevention member to the endless belt in the non-durable endless belt having the meandering prevention member produced in the same manner was compared with the joining strength of the meandering prevention member to the endless belt after the durability test, The joint strength of about 90% of the belt was maintained. Here, the bonding strength of the belt was measured by measuring the 90 ° peel strength as the bonding strength.

  Further, in FIG. 1, the diameters of the rollers 8, 9, 10, 11 that stretch the intermediate transfer belt 6 and the winding angles of the intermediate transfer belt 6 around the rollers 8, 9, 10, 11 are shown below. It was street. The winding angle is a portion shown in FIG. Further, the intermediate transfer belt 6 was stretched by a tension roller 10 with a total pressure of 49N.

Diameter Wrapping angle Primary transfer roller 8 25mm 50 °
Secondary transfer counter roller 11 25mm 110 °
Tension roller 10 30mm 100 °
Drive roller 9 30mm 100 °
As described above, even when the diameter of each of the rollers 8, 9, 10, and 11 is small and the winding angle is large, the meandering prevention member is formed of a foam to prevent peeling of the meandering prevention member and damage to the belt. can do.

(Example 2)
<Production of endless belt>
Three kinds of materials are blended as follows.

Polycarbonate resin 100 parts by weight Carbon black 12 parts by weight Antioxidant 0.5 part by weight Three types of materials blended as described above were kneaded in a biaxial extrusion kneader, and additives such as carbon black were sufficiently contained in the binder. Were uniformly dispersed to obtain a raw material for molding. Further, this was made into a kneaded product having a particle diameter of 1 to 2 mm, and then charged into a hopper of a single screw extruder, and adjusted to a temperature of 270 to 290 ° C. and extruded to obtain a melt.

  Next, this melt was introduced into an extrusion die for a cylindrical single layer having a diameter of 200 mm and a die gap of 900 μm, and then expanded and expanded by blowing air from an air introduction path, with a final shape dimension of 250 mm in diameter and 150 μm in thickness. It was. Furthermore, it cut | disconnected with the belt width 350mm, and obtained the seamless belt.

  On the other hand, a reinforcing tape made of polyethylene terephthalate resin was used as the reinforcing member, and was stuck to both ends of the outer surface of the seamless belt to obtain a seamless belt having a reinforcing member on the outer peripheral surface.

<Join the meandering prevention member to the endless belt>
An endless belt having a meandering prevention member obtained by sticking the same meandering prevention member as in Example 1 to the inner peripheral surface of an endless belt having a reinforcing member obtained as described above with a double-sided tape having an acrylic adhesive. Got.

  The obtained endless belt having the meandering preventing member was incorporated as a transfer conveyance belt 61 of the color laser printer having the configuration shown in FIG. 2, and a durability test of 100,000 full colors corresponding to 40,000 rotations of the transfer conveyance belt 61 was performed. As a result, problems such as peeling of the meandering preventing member and cracks and chippings at the belt end did not occur, and the durability was sufficient. Also, the amount of color misregistration was as good as about 50 μm on average.

  Furthermore, when the joining strength of the meandering prevention member to the endless belt in the non-durable endless belt having the meandering prevention member produced in the same manner was compared with the joining strength of the meandering prevention member to the endless belt after the durability test, The joint strength of about 80% of the belt was maintained. Here, the bonding strength of the belt was measured by measuring the 90 ° peel strength as the bonding strength.

  In FIG. 2, the diameters of the rollers 9, 91, 10 that stretch the transfer / conveyance belt 61 and the winding angle of the transfer / conveyance belt 61 around the rollers are as shown below. Further, the transfer / conveying belt 61 was stretched by the tension roller 10 with a total pressure of 68.6N.

Diameter Wrapping angle Drive roller 9 35mm 150 °
Followed roller 91 30mm 165 °
Tension roller 10 20mm 45 °
Thus, even when the diameter of each of the rollers 9, 10, 91 is small and the winding angle is large, the meandering prevention member is formed of foam to prevent the meandering prevention member from peeling and the belt from being damaged. Can do.

(Example 3)
<Production of endless belt>
A seamless belt having a reinforcing member on the inner peripheral surface was obtained in the same manner as in Example 1.

<Join the meandering prevention member to the endless belt>
A polyurethane foam having a rectangular cross section with a thickness of 2 mm and a width of 3 mm on the inner peripheral surface of the reinforcing member of the seamless belt obtained as described above, and having a skin layer on the four sides of the cross section, an acrylic adhesive The endless belt which has a meandering prevention member was obtained by sticking with a double-sided adhesive tape. Here, the thickness of the skin layer was 2 μm, and the porosity of the skin layer was 8%. The average foam diameter of the foam was 12 μm, and the porosity of the foam was 25%.

  The obtained endless belt having the meandering preventing member was incorporated as an intermediate transfer belt 6 of the color laser printer having the configuration shown in FIG. 1, and a durability test was conducted on 10,000 full-color sheets corresponding to 40,000 rotations of the intermediate transfer belt 6. As a result, problems such as peeling of the meandering preventing member and cracks and chippings at the belt end did not occur, and the durability was sufficient. Also, the amount of color misregistration was as good as about 40 μm on average.

  Furthermore, when the joining strength of the meandering prevention member to the endless belt in the non-durable endless belt having the meandering prevention member produced in the same manner was compared with the joining strength of the meandering prevention member to the endless belt after the durability test, The joint strength of about 50% of the belt was maintained. Here, the bonding strength of the belt was measured by measuring the 90 ° peel strength as the bonding strength.

Example 4
<Production of endless belt>
A seamless belt having a reinforcing member on the inner peripheral surface was obtained in the same manner as in Example 1.

<Join the meandering prevention member to the endless belt>
A polyurethane foam having a rectangular cross section with a thickness of 2 mm and a width of 3 mm on the inner peripheral surface of the reinforcing member of the seamless belt obtained as described above, and having a skin layer on the four sides of the cross section, an acrylic adhesive The endless belt which has a meandering prevention member was obtained by sticking with a double-sided adhesive tape. Here, the thickness of the skin layer was 8 μm, and the porosity of the skin layer was 25%. The average foam diameter of the foam was 270 μm, and the porosity of the foam was 70%.

  The obtained endless belt having the meandering preventing member was incorporated as an intermediate transfer belt 6 of the color laser printer having the configuration shown in FIG. 1, and a durability test was conducted on 10,000 full-color sheets corresponding to 40,000 rotations of the intermediate transfer belt 6. As a result, problems such as peeling of the meandering preventing member and cracks and chippings at the belt end did not occur, and the durability was sufficient. The average color misregistration amount was about 90 μm.

  Furthermore, when the joining strength of the meandering prevention member to the endless belt in the non-durable endless belt having the meandering prevention member produced in the same manner was compared with the joining strength of the meandering prevention member to the endless belt after the durability test, The joint strength of about 90% of the belt was maintained. Here, the bonding strength of the belt was measured by measuring the 90 ° peel strength as the bonding strength.

(Example 5)
<Production of endless belt>
A seamless belt having a reinforcing member on the inner peripheral surface was obtained in the same manner as in Example 1.

<Join the meandering prevention member to the endless belt>
A double-sided tape having a polyurethane foam having an acrylic adhesive and a polyurethane foam having a rectangular cross section of 2 mm in thickness and 3 mm in width on the inner peripheral surface of the reinforcing member of the seamless belt obtained as described above. The endless belt having a meandering prevention member was obtained. Here, the average foam diameter of the foam was 50 μm, and the porosity of the foam was 50%.

  The obtained endless belt having the meandering preventing member was incorporated as an intermediate transfer belt 6 of the color laser printer having the configuration shown in FIG. 1, and a durability test was conducted on 10,000 full-color sheets corresponding to 40,000 rotations of the intermediate transfer belt 6. As a result, problems such as peeling of the meandering preventing member and cracks and chippings at the belt end did not occur, and the durability was sufficient. The average color misregistration amount was about 80 μm on average.

  Furthermore, when the joining strength of the meandering prevention member to the endless belt in the non-durable endless belt having the meandering prevention member produced in the same manner was compared with the joining strength of the meandering prevention member to the endless belt after the durability test, The joint strength of about 75% of the belt was maintained. Here, the bonding strength of the belt was measured by measuring the 90 ° peel strength as the bonding strength.

(Example 6)
<Production of endless belt>
A seamless belt having a reinforcing member on the inner peripheral surface was obtained in the same manner as in Example 1.

<Join the meandering prevention member to the endless belt>
A polyurethane foam having a rectangular cross section with a thickness of 2 mm and a width of 3 mm on the inner peripheral surface of the reinforcing member of the seamless belt obtained as described above, and having a skin layer on the four sides of the cross section, an acrylic adhesive The endless belt which has a meandering prevention member was obtained by sticking with a double-sided adhesive tape. Here, the thickness of the skin layer was 1 μm, and the porosity of the skin layer was 5%. The average foam diameter of the foam was 10 μm, and the porosity of the foam was 15%.

  The obtained endless belt having the meandering preventing member was incorporated as an intermediate transfer belt 6 of the color laser printer having the configuration shown in FIG. 1, and a durability test was conducted on 10,000 full-color sheets corresponding to 40,000 rotations of the intermediate transfer belt 6. As a result, problems such as peeling of the meandering preventing member and cracks and chippings at the belt end did not occur, and the durability was sufficient. The amount of color misregistration was as good as about 40 μm on average.

  Furthermore, when the joining strength of the meandering prevention member to the endless belt in the non-durable endless belt having the meandering prevention member produced in the same manner was compared with the joining strength of the meandering prevention member to the endless belt after the durability test, The joint strength of about 30% of the belt was maintained. Here, the bonding strength of the belt was measured by measuring the 90 ° peel strength as the bonding strength.

(Example 7)
<Production of endless belt>
A seamless belt having a reinforcing member on the inner peripheral surface was obtained in the same manner as in Example 1.

<Join the meandering prevention member to the endless belt>
A double-sided tape having a polyurethane foam having an acrylic adhesive and a polyurethane foam having a rectangular cross section of 2 mm in thickness and 3 mm in width on the inner peripheral surface of the reinforcing member of the seamless belt obtained as described above. The endless belt having a meandering prevention member was obtained. Here, the average foam diameter of the foam was 330 μm, and the porosity of the foam was 82%.

  The obtained endless belt having the meandering preventing member was incorporated as an intermediate transfer belt 6 of the color laser printer having the configuration shown in FIG. 1, and a durability test was conducted on 10,000 full-color sheets corresponding to 40,000 rotations of the intermediate transfer belt 6. As a result, problems such as peeling of the meandering preventing member and cracks and chippings at the belt end did not occur, and the durability was sufficient. The color misregistration amount was as large as about 120 μm on average, but it was a level that could sufficiently withstand practical use.

  Furthermore, when the joining strength of the meandering prevention member to the endless belt in the non-durable endless belt having the meandering prevention member produced in the same manner was compared with the joining strength of the meandering prevention member to the endless belt after the durability test, The joint strength of about 90% of the belt was maintained. Here, the bonding strength of the belt was measured by measuring the 90 ° peel strength as the bonding strength.

  Next, a comparative example will be described.

(Comparative Example 1)
<Production of endless belt>
A seamless belt having a reinforcing member on the inner peripheral surface was obtained in the same manner as in Example 1 described above.

  Then, a seamless belt having this reinforcing member was incorporated as an intermediate transfer belt 6 of the color laser printer having the configuration shown in FIG. 1 without providing a meandering preventing member, and a full color durability test was conducted. As a result, the endurance test was stopped because cracks occurred at the end of the belt when about 50 sheets of images were output due to stress due to the belt moving in one direction of the roller due to meandering.

(Comparative Example 2)
<Production of endless belt>
A seamless belt having a reinforcing member on the outer peripheral surface was obtained in the same manner as in Example 2 described above.

<Join the meandering prevention member to the endless belt>
A meandering-preventing member made of polyurethane elastomer having a thickness of 2 mm and a width of 3 mm and having a rectangular cross section on the inner peripheral surface of the seamless belt having the reinforcing member obtained as described above is a double-sided tape having an acrylic adhesive. By sticking, an endless belt having a meandering prevention member was obtained.

  The obtained endless belt having the meandering prevention member was incorporated as a transfer conveyance belt 61 of the color laser printer having the configuration shown in FIG. 2, and a full color durability test was conducted. As a result, the endurance test was stopped because the image forming apparatus stepped out and the image could not be output because the meandering prevention member peeled off when the endured about 50,000 sheets (transfer conveyor belt about 20,000 revolutions). . Moreover, when the durable belt was confirmed visually at that time, many minute cracks were seen in the belt edge part.

1, 1Y, 1M, 1C, 1K Photosensitive drum 2 Corona chargers 2Y, 2M, 2C, 2K Primary charging rollers 41-44, 4Y, 4M, 4C, 4K Developer 6 Intermediate transfer belt 6a Belt body 6b Meandering prevention member 6c Skin Layer 8 Primary transfer roller 8Y, 8M, 8C, 8K Transfer sheet 9, 91 Drive roller 10 Tension roller 11 Secondary transfer counter roller 12 Secondary transfer roller 13 Transfer material 61 Transfer conveyance belt 61a Belt body 61b Meander prevention portion 61c Skin layer R Roller R1 groove

Claims (7)

An endless belt body and a meandering prevention member provided on an inner peripheral surface of the belt body, the belt body is stretched by a tension member, and the belt body and the meandering prevention member are movable. Yes, in the belt where the meandering prevention member is in contact with the tension member and restricts the movement of the belt body and the meandering prevention member in the direction perpendicular to the movement direction,
The meander-preventing member is entirely formed of a foam, and the foam has a first foamed region and a second foamed region having voids at a ratio lower than that of the first foamed region. belt and, prior Symbol foam region to be bonded to the inner circumferential surface of the belt body, characterized in that a second bubble-generating region. The foam has a square or rectangular cross-sectional shape in a direction perpendicular to the moving direction of the belt, and the second foamed region includes at least an inner surface and an inner surface bonded to an inner peripheral surface of the belt body. 2. The belt according to claim 1, wherein the belt is formed on opposing outer surfaces, and the first foaming region is between the inner surface and the second foaming region of the outer surface.   The foam has a square or rectangular cross-sectional shape in a direction perpendicular to the moving direction of the belt, and the second foamed region is formed on all four sides of the square or the rectangular shape, The belt according to claim 1, wherein a region between the second foaming regions formed on four sides is the first foaming region.   The belt according to any one of claims 1 to 3, wherein the first foamed region has a porosity of 20% or more and 80% or less.   The belt according to any one of claims 1 to 4, wherein the second foam region has a porosity of less than 20%.   6. The movement of the meandering prevention member in a direction perpendicular to the movement direction of the belt main body and the meandering prevention member is restricted by a side end of the stretching member. The belt described in. An image carrier that carries a toner image, and an intermediate transfer belt to which a toner image formed on the image carrier is transferred or a transfer conveyance belt that carries a transfer material, the intermediate transfer belt from the image carrier to the intermediate transfer belt In an image forming apparatus for transferring a toner image onto a transfer material transferred from the image carrier to the transfer material conveyed by the transfer conveyance belt
The image forming apparatus according to claim 1, wherein the intermediate transfer belt or the transfer conveyance belt is the belt according to claim 1.

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