JP2014081399A - Slide sheet, fixing apparatus, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide sheet having improved wear resistance and service life.SOLUTION: A slide sheet 68 includes a woven fabric base material 66 having a yarn density distribution in a direction crossing a sliding direction (hollow arrow direction), and a coating layer 69 provided on a surface of the woven fabric base material 66. The woven fabric base material 66 in the slide sheet 68 has a central band area, which is formed along the sliding direction and has yarn density higher than that of end band areas formed on both sides of the central band area.

Description

  The present invention relates to a sliding sheet, a fixing device, and an image forming apparatus.

  Conventionally, in an image forming apparatus such as an electrophotographic copying machine or printer, a process for fixing an unfixed toner image held on a recording medium such as paper on the recording medium to form an image is called a fixing process. It is out. Conventionally, methods such as pressure fixing, oven fixing, and solvent fixing are used as the fixing step, but heat is effectively transmitted, the toner image is fixed more firmly, and is relatively safe. From the viewpoint, the thermal pressure fixing method is most commonly used. In this thermal pressure fixing method, a recording medium on which an unfixed toner image is held is passed through a nip constituted by two heated rolls or belts, and when the nip passes, the recording medium is heated by the rolls or belts to be in a molten state. This is a method in which a toner image is fixed on a recording medium by pressing the unfixed toner image that has been pressed against the recording medium with a nip pressure.

  2. Description of the Related Art In recent years, an electromagnetic induction heating and fixing method that has been introduced is provided with a coil and a high-frequency power source in addition to a conventional heating and fixing member and a pressure member corresponding to two heated rolls or belts. The coil is installed inside the heat fixing member or at a position close to the external heat fixing member, and is electrically connected to a high frequency power source. As a heat fixing member, induction heating can be performed in either a roll shape or a belt shape as long as a metal heating layer is provided. In any case, an induction electromotive force is generated in the metal heating layer of the heat-fixing member by flowing a high-frequency current through a coil arranged at a position close to the heat-fixing member, and an eddy current flows to heat the heat-fixing member. Has been.

  Further, in the belt-type induction heating fixing member, in order to form a nip region between a pressure member made of a rotatable rotating member and a resin film tubular body (for example, a belt), a pressing member is provided inside the resin film tubular body. Is arranged. In order to form a nip region between the pressure member and the resin film tubular body (for example, a belt) at a pressure equivalent to that of the pressure member, and to secure the width of the nip region, A pressing pad made of an elastic body is provided. Here, in order to improve the slidability between the pressing pad and the resin film tubular body, in recent years, proposals have been made to interpose a sliding sheet.

  For example, Patent Document 1 discloses that side protrusions arranged side by side in a sliding direction on one surface of a sliding sheet and side by side in an orthogonal direction orthogonal to the sliding direction (that is, the axial direction of the pressure member). Are formed in a lattice shape, and the length in the orthogonal direction between the adjacent vertical convex portions is longer than the length in the sliding direction between the adjacent horizontal convex portions. An improved sliding sheet is disclosed. Here, the vertical convex part and the horizontal convex part disclosed in Patent Document 1 are formed in a grid pattern in one form over the entire sliding sheet.

  Further, in Patent Document 2, the sliding sheet is made of a single resin, and at least the sliding amount of the endless belt is substantially different in the amount of resin per unit area depending on the position in the sliding sheet surface. A sliding sheet is disclosed in which a repetition of a thick portion and a thin portion is formed, and a concave portion and a convex portion are provided on the sliding surface.

JP 2008-164686A JP 2009-15227 A

  An object of the present invention is to provide a sliding sheet, a fixing device, and an image forming apparatus that have higher wear resistance than conventional ones.

  As a result of intensive studies to solve the above problems, the present invention has been reached as follows.

  (1) It has a woven fabric base material having a woven density distribution in a direction intersecting the sliding direction, and a coating layer provided on the surface of the woven fabric base material, In the sliding sheet, the weaving density of the central band region along the sliding direction is higher than the weaving density of both end band regions sandwiching the central band region.

  (2) The woven fabric base material is formed by plain weaving, and the weaving density of the central belt region along the sliding direction is 30/25 mm or more per unit dimension in the direction intersecting the sliding direction / 50 / The weave density distribution is 25 mm or less, and the weave density of both end band regions sandwiching the central band region is 10/25 mm or more and 30/25 mm or less per unit dimension in the direction intersecting the sliding direction. The sliding sheet according to (1) above.

  (3) The unfixed toner by sandwiching a recording medium carrying an unfixed toner image in a nip portion formed between the rotatable rotating member and the rotating member and being pressed against the rotating member. A fixing device comprising: a rotatable film tubular body for fixing an image on the recording medium; and the sliding sheet according to (1) or (2) interposed between the film tubular body and a pressing member. Device.

  (4) a latent image forming means for forming a latent image on the image holding member, a developing means for developing the latent image using a developer for developing an electrostatic image, and the developed toner image via an intermediate transfer member. The image forming apparatus includes: a transfer unit that transfers the toner image on the transfer body; and a fixing unit that fixes the toner image on the transfer body. The fixing unit is described in (3) above. The image forming apparatus includes a fixing device.

  According to the first aspect of the present invention, the wear resistance is increased as compared with the case where the present configuration is not provided.

  According to the invention described in claim 2 of the present application, the wear resistance is higher than in the case where the present configuration is not provided.

  According to the third aspect of the present invention, it is possible to obtain a fixing device including a sliding sheet having high wear resistance as compared with the case where this configuration is not provided.

  According to the invention described in claim 4 of the present application, an image forming apparatus having a fixing device provided with a sliding sheet having high wear resistance as compared with the case without this configuration can be obtained.

FIG. 2 is a schematic configuration diagram illustrating an example of a configuration of a fixing device according to the present invention. It is a top view sectional view explaining an example of a sliding sheet. It is II sectional drawing of FIG. 2 explaining an example of a sliding sheet. It is drawing explaining an example of the manufacturing method of the sliding sheet in this invention. 1 is a schematic configuration diagram illustrating an example of a configuration of an image forming apparatus according to the present invention.

  A sliding sheet, a fixing device, and an image forming apparatus according to an embodiment of the present invention will be described below.

[Fixing device]
First, the fixing device in the present embodiment will be described below with reference to FIG. Note that a fixing device that employs an electromagnetic induction heating method will be described as an example of the fixing device in the present embodiment.

  As shown in FIG. 1, a fixing device 60 according to the present embodiment is disposed in pressure contact with a pressure roll 62 that is a rotatable rotating member and a pressure roll 62 that is a rotating member. The unfixed toner image is fixed on the recording medium P by sandwiching the recording medium P holding the unfixed toner image in a pressure part N (hereinafter also referred to as “nip part N”) formed on It has a fixing belt 61 that is a tubular body, and a sliding sheet 68 that is interposed between the fixing belt 61 that is a tubular body and a pressing pad 64 that is a pressing member.

  For example, the sliding sheet 68 may be formed of only a fluororesin, but it is preferable to use a sheet obtained by forming a fluororesin layer on both surfaces of a heat-resistant fiber base material and firing the layer. For example, a glass cloth having a thickness of 30 μm to 600 μm is preferably used as the heat resistant fiber base material. This fluororesin sliding sheet is prepared by applying a fluororesin aqueous dispersion on both sides of a heat-resistant fiber base material, or impregnating the base material into the dispersion by a dipping method and then firing the dispersion. The As the fluororesin, polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and the like are preferable. Polytetrafluoroethylene is particularly preferable in terms of heat resistance, mechanical properties, and the like. Ethylene is preferably used.

  Further, the configuration of the fixing device 60 will be described with reference to FIG. The fixing device 60 includes a fixing belt 61 that is a tubular body, a magnetic field generating unit 85 as an example of a heating member that generates heat by a magnetic field generated by an alternating current, and a pressure member that is disposed to face the fixing belt 61. As an example, a pressure pad 62 that is pressed from a pressure roll 62 that is a rotating member is provided via a pressure roll 62 and a fixing belt 61.

  The fixing belt 61, which is a tubular body, is rotatably supported by a pressure pad 64, a belt guide member 63, and edge guide members (not shown) disposed at both ends of the fixing belt 61. Then, it is brought into pressure contact with the pressure roll 62 at the pressure part (nip part) N and is rotated in the direction of arrow E following the pressure roll 62.

  Examples of the tubular body described above include a metal tubular body and a resin tubular body. As the metallic tubular body, stainless steel is preferable from the viewpoint of durability and thermal conductivity. As the stainless steel, for example, martensitic stainless steel is used. Examples include steel, ferritic stainless steel, austenitic stainless steel, austenitic / ferritic duplex stainless steel, and precipitation hardened stainless steel. Moreover, if it mentions as a stainless steel by the standard name prescribed | regulated by JIS standard, for example, SUS201, SUS202, SUS301 to SUS305, SUS316, SUS317, etc. austenitic stainless steel, SUS329J1 austenitic ferrite duplex stainless steel, SUS403 Martensitic stainless steel such as SUS420, ferritic stainless steel such as SUS405, SUS430 and SUS430LX, martensitic precipitation hardened stainless steel such as SUS630, and the like. However, the invention is not limited to this, and a metal or metal alloy that satisfies the conditions of durability and thermal conductivity or a metal plate composed of two or more layers may be used as the fixing belt. The resin tubular body is preferably a polyimide resin, a polyamide resin, or a polycarbonate resin. It is also preferable to use a composite material in which a metal material and a resin material are combined.

  The structure of the metal tubular body used for the fixing belt 61 will be described later.

  The belt guide member 63 is attached to a holder 65 disposed inside the fixing belt 61. The belt guide member 63 is formed by a plurality of ribs (not shown) directed in the rotation direction of the fixing belt 61 to reduce the contact area with the inner peripheral surface of the fixing belt 61. Further, the belt guide member 63 is formed of a heat resistant resin such as PFA (perfluoroalkyl vinyl ether copolymer) or PPS (polyphenylene sulfide) having a low friction coefficient and low thermal conductivity. Thus, the sliding resistance between the belt guide member 63 and the inner peripheral surface of the fixing belt 61 is reduced, and the heat divergence is reduced.

  The pressure pad 64 is pressed from the pressure roll 62 via the fixing belt 61 to form the pressure portion N. The pressing pad 64 supports the pressing roll 62 by a holder 65 so as to press the pressing roll 62 with a load of, for example, 35 kgf by a spring or an elastic body. The pressing pad 64 is made of an elastic body such as silicone rubber or fluorine rubber, for example. The pressing pad 64 has a concave portion and a convex portion on the pressure roll 62 side. As a result, when the fixing belt 61 moves away from the surface of the pressing pad 64 on the pressure roll 62 side, a sudden change in curvature occurs, and the recording medium P after fixing is easily peeled off from the fixing belt 61.

  The peeling assisting member 70 disposed in the vicinity of the downstream side of the pressure unit N is held by the baffle holder 72 in a direction (counter direction) in which the peeling baffle 71 faces the rotation direction of the fixing belt 61. Further, a sliding sheet 68 is disposed between the pressing pad 64 and the fixing belt 61 to reduce sliding resistance between the inner peripheral surface of the fixing belt 61 and the pressing pad 64. In the present embodiment, the sliding sheet 68 is configured separately from the pressing pad 64, and both ends are fixed to the holder 65.

  A lubricant application member 67 is disposed in the holder 65 over the longitudinal direction of the fixing device 60. The lubricant applying member 67 contacts the inner peripheral surface of the fixing belt 61 and supplies the lubricant to the sliding portion between the fixing belt 61 and the sliding sheet 68. Examples of the lubricant include liquid oils such as silicone oil and fluorine oil; grease in which a solid substance and a liquid are mixed, and a combination thereof.

  The pressure roll 62 includes, for example, a solid iron core (columnar core) 621 having a diameter of 16 mm, a rubber layer 622 such as a silicone sponge having a thickness of 12 mm, which covers the outer peripheral surface of the core 621, and the like, for example And a surface layer 623 with a heat-resistant resin coating such as PFA having a thickness of 30 μm or a heat-resistant rubber coating. In addition, as a manufacturing method of the pressure roll 62, for example, a fluororesin tube in which an adhesion primer is applied to the inner peripheral surface of a PFA tube (becomes the surface layer 623) and a solid shaft (becomes the core 621) are used. Set in a molding die, inject liquid foamed silicone rubber between the fluororesin tube and the solid shaft, and then vulcanize and foam the silicone rubber by heat treatment (for example, 150 ° C., 2 hours) to form a rubber layer The method of forming 622 is mentioned.

  The pressure roll 62 is disposed so as to face the fixing belt 61, rotates in the direction of arrow D at a process speed of, for example, 140 mm / sec, and drives the fixing belt 61. Further, the pressure belt 62 is held by the pressure roll 62 and the pressure pad 64 to form the pressure portion N, and the recording medium P holding the unfixed toner image is passed through the pressure portion N. Then, heat and pressure are applied to fix the unfixed toner image on the recording medium P.

  The magnetic field generation unit 85 has a cross-section with a curved shape that follows the shape of the fixing belt 61, and is installed with an outer peripheral surface of the fixing belt 61 with a gap of about 0.5 mm to 2 mm, for example. The magnetic field generation unit 85 includes an excitation coil 851 that generates a magnetic field, a coil support member 852 that holds the excitation coil 851, and an excitation circuit 853 that supplies current to the excitation coil 851.

The exciting coil 851 is formed, for example, by winding a litz wire, which is a bundle of about 16 to 20 copper wires having a diameter of 0.5 mm that are insulated from each other, in a closed ring shape such as an oval shape, an elliptical shape, or a rectangular shape. Use things. By applying an alternating current having a predetermined frequency to the exciting coil 851 by the exciting circuit 853, an alternating magnetic field H is generated around the exciting coil 851. When the alternating magnetic field H crosses the metal layer of the fixing belt 61, an eddy current I is generated so as to generate a magnetic field that hinders the change of the alternating magnetic field H by electromagnetic induction. The frequency of the alternating current applied to the exciting coil 851 is set, for example, from 10 kHz to 50 kHz. When the eddy current I flows through the metal layer of the fixing belt 61, Joule heat is generated by electric power W (W = I ² R) proportional to the resistance value R of the metal layer, and the fixing belt 61 is heated.

  The coil support member 852 is made of a nonmagnetic material having heat resistance. Examples of such a non-magnetic material include heat resistant resins such as heat resistant glass, polycarbonate, polyethersulfone, and PPS, or heat resistant resins obtained by mixing glass fibers with these.

  In the present embodiment, the electromagnetic induction heating type fixing device 60 including the magnetic field generation unit 85 has been described as an example of a heating member that heats the fixing belt 61. However, as the heating member, a radiation lamp heating element, a resistance heating element, and the like. The body can also be adopted.

  Examples of the radiant lamp heating element include a halogen lamp. Examples of the resistance heating element include iron-chromium-aluminum, nickel-chromium, platinum, molybdenum, tantalum, tungsten, silicon carbide, molybdenum-silicide, and carbon.

  In the fixing device 60, the fixing belt 61 is driven and rotated by the rotation of the pressure roll 62 in the direction of arrow D, and is exposed to the magnetic field generated by the excitation coil 851. At this time, an eddy current is generated in the metal layer in the fixing belt 61, and the outer peripheral surface of the fixing belt 61 is heated to a temperature at which fixing can be performed. The fixing belt 61 heated in this way moves to the pressure part N with the pressure roll 62. The recording medium P having the unfixed toner image provided on the surface thereof is carried into the fixing device 60 via the fixing inlet guide 56 by the conveying means. When the recording medium P passes through the pressure part N of the fixing belt 61 and the pressure roll 62, the unfixed toner image is heated by the fixing belt 61 and fixed on the surface of the recording medium P. Thereafter, the recording medium P on which the image is formed is conveyed by the conveying unit and is discharged from the fixing device 60. Also, the fixing belt 61 whose surface temperature on the outer peripheral surface has been lowered after the fixing process in the pressurizing unit N rotates in the direction of the excitation coil 851 and is heated again in preparation for the next fixing process.

[Sliding sheet]
Below, the sliding sheet | seat in this Embodiment is demonstrated using FIGS. 2-4. As shown in FIG. 2, the sliding sheet 68 in the present embodiment includes a woven fabric substrate 66 having a woven density distribution in a direction intersecting the sliding direction (the white arrow direction shown in FIG. 2), And a lubricating coating layer 69 (as an example of a coating layer) provided on the surface of the woven fabric substrate 66.

  Further, as shown in FIGS. 2 and 3, the woven fabric base 66 in the sliding sheet 68 in the present embodiment is such that the weave density of the central belt region along the sliding direction is the both ends sandwiching the central belt region. It is formed higher than the weave density of the belt region. Here, the end band region may have a width of about 1/2 or more and 1/3 or less from the end with respect to the width in the direction intersecting the sliding direction of the sliding sheet 68. Further, in the sliding sheet 68 in the present embodiment, it is sufficient that the central belt region has a higher weaving density than the both end band regions. For example, the central belt region has a weaving density in the both end band regions. What is necessary is just about 1.5 times or more and 3.0 times or less of a density.

  Here, as shown in FIG. 1, when the nip region is formed by the fixing belt 61 and the pressure roll 62, for example, the load from the core composed of the pressing pad 64, the holder 65, and the lubricant application member 67 is It is considered that the pressure becomes higher at both end portions than at the central portion along the rotation direction of the pressure roll 62, and the pressure distribution is biased in the nip region. The pressure deviation is considered to be high at both ends of the fixing belt 61. On the other hand, in the sliding sheet 68 of the present embodiment, the weaving density of the central band region along the sliding direction is higher than the weaving density of both end band regions sandwiching the central band region, as shown in FIG. The unevenness of the both end band regions of the sliding sheet 68 is larger than the unevenness of the central band region of the sliding sheet 68, and as a result, the both end band regions having deeper recesses than the recesses of the central band region, Compared to the case where a sliding sheet supplied with more lubricant and having no woven density distribution is used, the friction between both ends of the fixing belt 61 and the sliding sheet 68, which are film tubular bodies, is reduced, and sliding It is considered that the service life of the sheet 68 is extended.

  Examples of the woven fabric base 66 in the sliding sheet 68 of the present embodiment include a glass cloth made of woven fabric made from glass fibers. The weaving method of the woven fabric may be any of a three-layer structure consisting of a plain weave, a twill weave, and a satin weave, but “plain weave” is more preferable in consideration of the uniformity of unevenness on the surface. Here, “plain weave” refers to a structure in which warps (hereinafter also referred to as “warp”) and wefts (hereinafter also referred to as “weft”) are alternately combined one by one. “Twill weave” refers to a structure in which weaves are slanted, and means that twills of various angles are expressed by changing the thickness and density of warps and wefts, or by skipping yarns. “Sakon weave”, also called satin, refers to a weaving method characterized by long warp or weft yarn on the surface and gloss and smoothness.

  In the woven fabric base 66 in the sliding sheet 68 of the present embodiment, for example, when the woven fabric base 66 is formed of a plain weave, the woven density of the central band region along the sliding direction is the sliding direction. 30/25 mm to 50/25 mm per unit dimension in the direction intersecting with respect to the unit, and the weave density of the both end band regions sandwiching the central band region is the unit dimension in the direction intersecting the sliding direction. It is preferable to have a woven density distribution of 10/25 mm or more and 30/25 mm or less. When the ratio of the woven density between the central belt region and the belt region of the sliding sheet 68 is outside the above range, the wear resistance with respect to a predetermined use frequency of the sliding sheet 68 may not be obtained. Here, the “weave density” refers to the number of yarns driven per unit length, and the “weave density” used in the weave density distribution in this specification is the sliding direction (the direction of the white arrow shown in FIG. 2). The number of yarns driven per unit length in the direction intersecting with.

  Further, the woven density distribution of the woven fabric base material 66 in the sliding sheet 68 of the present embodiment may be formed, for example, by joining two or more kinds of woven fabrics having different woven densities, and the sliding direction. When weaving a plain weave fabric with warp (warp) as the warp yarn, the thickness of the weft (weft) and the weft (weft) is not changed, and the warp (warp) thickness is changed. You may form with the opposite woven fabric woven so that the woven density might be formed.

  In addition, the lubricating coating layer 69 in the sliding sheet 68 of the present embodiment is made of, for example, a fluororesin that has been treated with a lipophilic agent within a thickness range of 10 μm to 50 μm. Here, there is no restriction | limiting in particular as a fluororesin, For example, polytetrafluoroethylene (PTFE); tetrafluoroethylene perfluoromethyl vinyl ether copolymer (MFA), tetrafluoroethylene perfluoroethyl vinyl ether copolymer (EFA) And tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA) such as tetrafluoroethylene perfluoropropyl vinyl ether copolymer. Further, tetrafluoroethylene hexafluoropropylene copolymer (FEP), ethylene tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychloroethylene trifluoride (PCTFE), polyvinyl fluoride (PVF), etc. Can be mentioned. Among these, polytetrafluoroethylene (PTFE), tetrafluoroethylene perfluoromethyl vinyl ether copolymer (MFA), tetrafluoroethylene perfluoroethyl vinyl ether copolymer (particularly in terms of heat resistance, mechanical properties, etc. A tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA) such as EFA) is preferably used. The oleophilic agent is not particularly limited, and examples thereof include reactive organopolysiloxane, alkylsilane, and organic titanate.

Furthermore, the sliding sheet 68 in the present embodiment does not have a hole on the concave and convex surface to be impregnated with a lubricant, which will be described later, and 0.01 mg / mm as an index of oil impregnation. Those of ³ to 0.2 mg / mm ³ (preferably 0.01 mg / mm ³ to 0.15 mg / mm ³ ) are shown. The amount of oil impregnation is the weight after rotating oil for 1 minute while applying oil on the uneven surface of the sliding sheet 68 and pressing a roll around which paper is wound with a force of 5 kg / cm ^2. It is a value calculated by the difference between the dry weight.

  Specific examples of the lubricants that can be applied include the above-described grease, dimethyl silicone oil, dimethyl silicone oil with an organic metal salt added, dimethyl silicone oil with a hindered amine added, dimethyl silicone oil with an organic metal salt and a hindered amine added, and methylphenyl silicone. Examples thereof include oils, amino-modified silicone oils added with organic metal salts, and hindered amine-added amino-modified silicone oils.

  Next, an example of the manufacturing method of the sliding sheet 68 in this Embodiment is demonstrated using FIG. In FIG. 4, the method of manufacturing the sliding sheet 68 by joining two or more kinds of woven fabrics having different weave densities is described as an example, but the present invention is not limited to this.

  First, two types of glass cloths 300 and 302 having different weave densities are prepared. Here, as the glass cloth 302, a cloth having a high warp woven density, for example, a cloth having a warp of 30/25 mm or more and 50/25 mm or less per unit dimension, is prepared, while a woven density of the warp is used as the glass cloth 300. A low cross, for example, a cross having a warp of 10/25 mm to 30/25 mm per unit dimension is prepared. Next, the glass cloth 300 and 302 are impregnated in the fluororesin dispersion by an impregnation method, respectively, and the glass cloth 300, the glass cloth 302, and the glass cloth 300 are arranged in parallel in the order of the wefts of the three glass cloths. S200). Next, three glass cloths arranged in accordance with the weft weave texture were sandwiched between two oleophilic fluororesin sheets, and these were pressure baked to form a lubricating coating layer 69 on the surface. The joined body 400 having an uneven surface is produced (S202). Next, the joined body 400 is first cut into a predetermined short side width along the weft (corresponding to “Cut (1)” in FIG. 4), and then the predetermined long side along the warp It was cut into a width (corresponding to “Cut (2)” in FIG. 4) (S204). This cutting sequence is performed by cutting along the weft direction woven at equal intervals as much as possible, so that the measurement of the short side width is performed relatively accurately, and then, according to the width of the central band region and the both end band regions. By cutting along the warp direction, a sliding sheet 68 having a lubricating coating layer 69 formed on the surface of the woven fabric substrate 66 having a predetermined woven density distribution is obtained. In FIG. 4, two types of glass cloths having different weaving densities are used in contact with each other. However, the present invention is not limited to this, and two or more kinds of glass cloths may be appropriately connected together. You may use the opposite glass cloth woven so that it may differ in a center part area | region and a both-ends area | region. Furthermore, the lubricating coating layer 69 is formed by pressurizing and firing two oleophilic fluororesin sheets sandwiching a glass cloth, but is not limited thereto, and includes a oleophilic fluororesin. The solution may be applied to a glass cloth and baked under pressure.

[Image forming apparatus]
FIG. 5 shows a schematic configuration of an image forming apparatus to which the sliding sheet and the fixing device of the present embodiment are applied. Here, an intermediate transfer type image forming apparatus generally called a tandem type will be described as an example.

  An image forming apparatus 100 shown in FIG. 5 includes a plurality of image forming units 1Y, 1M, 1C, and 1K that form toner images of respective color components by an electrophotographic method as an example of an image forming unit including a latent image forming unit and a developing unit. Is provided. Next, the image forming apparatus 100 sequentially transfers (primary transfer) each color component toner image formed by each of the image forming units 1Y, 1M, 1C, and 1K to the intermediate transfer belt (image holding member) 15 as an example of a transfer unit. A primary transfer unit 10 that transfers the superimposed toner image transferred onto the intermediate transfer belt 15 to a sheet that is a recording medium P (recording material (transfer object)). Prepare. Furthermore, the image forming apparatus 100 includes the above-described fixing device 60 that fixes the secondary transferred image on the recording medium P as an example of a fixing unit. Further, the image forming apparatus 100 includes a control unit 40 that controls the operation of each device (each unit).

  As shown in FIG. 5, each of the image forming units 1Y, 1M, 1C, and 1K includes a photosensitive drum 11 that rotates in the direction of arrow A, a charger 12 that charges the photosensitive drum 11, and a photosensitive drum 11. It has a laser exposure device 13 for writing an electrostatic latent image, and a developing device 14 that accommodates each color component toner and visualizes the electrostatic latent image on the photosensitive drum 11 with the toner. Further, a primary transfer roll 16 that transfers each color component toner image formed on the photosensitive drum 11 to the intermediate transfer belt 15 in the primary transfer unit 10, a drum cleaner 17 that removes residual toner on the photosensitive drum 11, and Have These image forming units 1Y, 1M, 1C, and 1K are arranged substantially linearly in the order of yellow (Y), magenta (M), cyan (C), and black (K) from the upstream side of the intermediate transfer belt 15. ing.

  The intermediate transfer belt 15 is circulated and driven in the direction of arrow B shown in FIG. As various rolls, a drive roll 31 that drives the intermediate transfer belt 15, a support roll 32 that supports the intermediate transfer belt 15, a tension roll 33 that applies a constant tension to the intermediate transfer belt 15 to prevent meandering, and a secondary transfer. A backup roll 25 provided in the section 20 and a cleaning backup roll 34 provided in a cleaning section for scraping the residual toner on the intermediate transfer belt 15 are provided.

  The primary transfer unit 10 includes a primary transfer roll 16 that faces the photosensitive drum 11 with the intermediate transfer belt 15 interposed therebetween. The secondary transfer unit 20 is disposed on the back side of the intermediate transfer belt 15 as a secondary transfer roll (transfer member) 22 disposed on the toner image holding surface side of the intermediate transfer belt 15 and a counter electrode of the secondary transfer roll 22. And a power supply roll 26 that applies a secondary transfer bias to the backup roll 25.

  An intermediate transfer belt cleaner 35 for removing residual toner and paper dust on the intermediate transfer belt 15 is provided on the downstream side of the secondary transfer unit 20. A reference sensor (home position sensor) 42 that generates a reference signal for taking an image forming timing in each of the image forming units 1Y, 1M, 1C, and 1K is disposed upstream of the yellow image forming unit 1Y. Further, an image density sensor 43 for adjusting image quality is disposed on the downstream side of the black image forming unit 1K.

  The recording medium transport system includes a recording medium container 50, a pickup roll 51 that takes out and transports the recording medium P in the recording medium container 50, a transport roll 52 that transports the recording medium P, and a recording medium P. A conveyance chute 53 to be sent to the next transfer unit 20, a conveyance belt 55 for conveying the recording medium P secondarily transferred by the secondary transfer roll 22 to the fixing device 60, and a fixing inlet for guiding the recording medium P to the fixing device 60. And a guide 56.

  A basic image forming process of the image forming apparatus 100 will be described. In the image forming apparatus 100 as shown in FIG. 5, after image processing is performed on image data output from an image reading apparatus (not shown) or the like, the image data is converted into four colors Y, M, C, and K. It is converted into material gradation data and output to the laser exposure unit 13. For example, each of the photosensitive drums that rotates the exposure beam Bm emitted from the semiconductor laser in the direction of arrow A of the image forming units 1Y, 1M, 1C, and 1K according to the input color material gradation data. 11 is irradiated. After the surface of each photoconductive drum 11 is charged by the charger 12, the surface is scanned and exposed by the laser exposure device 13 to form an electrostatic latent image. The formed electrostatic latent image is developed as a toner image of each color of Y, M, C, and K by each of the image forming units 1Y, 1M, 1C, and 1K.

  Next, the toner image formed on the photosensitive drum 11 is sequentially superimposed on the surface of the intermediate transfer belt 15 in the primary transfer unit 10 to perform primary transfer. The intermediate transfer belt 15 moves in the direction of arrow B and conveys the toner image to the secondary transfer unit 20. The recording medium conveyance system supplies the recording medium P from the recording medium container 50 in accordance with the timing at which the toner image is conveyed to the secondary transfer unit 20. In the secondary transfer unit 20, the unfixed toner image held on the intermediate transfer belt 15 is electrostatically transferred onto the recording medium P sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. Thereafter, the recording medium P on which the toner image has been electrostatically transferred is conveyed to the fixing device 60 by the conveying belt 55, and the fixing device 60 processes the unfixed toner image on the recording medium P with heat and pressure so To settle. The recording medium P on which the fixed image has been formed is conveyed to a paper discharge placement unit provided in the discharge unit of the image forming apparatus.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not restrict | limited to a following example. The evaluations described in the following production examples, examples and comparative examples were carried out by the following methods.

[Example 1]
One glass cloth (Arisawa Seisakusho) (94 mm × 100 mm) having a weaving density of 42 warps per unit dimension and a glass cloth having a weaving density of 16 warps per unit dimension (25 mm) Two sheets of Arisawa Seisakusho (94 mm × 100 mm) were each impregnated in a fluororesin dispersion (fluororesin: “Polyflon PTFE” manufactured by Daikin, solvent: water) by an immersion method. Next, a weft of three cloths in the order of a glass cloth having a weaving density of 16/25 mm, a glass cloth having a weaving density of 42/25 mm, and a glass cloth having a weaving density of 16/25 mm. Are arranged in parallel. Next, three glass cloths arranged in accordance with the weft weave are sandwiched between two polytetrafluoroethylene (PTFE) sheets ("Neofluon (registered trademark) ETFE" manufactured by Daikin), which have been subjected to lipophilic treatment, These are pressed and fired to produce a joined body having an uneven surface on which a lubricating coating layer 69 is formed. At the time of pressure firing, a fluoroelastomer sheet was appropriately disposed thereon, whereby a joined body was produced by aligning the PTFE sheet with the uneven shape of the glass cloth. Next, the joined body is cut to a predetermined short side width along the weft, and then cut to a predetermined long side width along the warp so as to have a predetermined woven density distribution, A sliding sheet A having a lubricating coating layer 69 formed on the surface of a woven fabric substrate 66 having a predetermined woven density distribution was produced. Here, the central band region of the sliding sheet A refers to an area of 78 mm to the left and right from the center of the long side width of the sliding sheet (that is, the width in the direction orthogonal to the sliding direction). The both end region of each means a region from 78 mm to the end on the left and right from the center of the long side width of the sliding sheet (that is, the width in the direction orthogonal to the sliding direction).

[Example 2]
Three glass cloths each have a warp density of 30 pieces / 25 mm per unit dimension / glass cloth (Arisawa Seisakusho) (94 mm × 100 mm) and 10 warps per unit dimension / A sliding sheet B was produced in the same manner as in Example 1 except that the glass cloth having a woven density of 25 mm (Arisawa Seisakusho) (94 mm × 100 mm) was replaced with two.

[Example 3]
Three glass cloths, one glass cloth (Arisawa Seisakusho) (94 mm × 100 mm) having a weaving density of 50 warps / 25 mm per unit dimension, and 30 warps per unit dimension / A sliding sheet C was produced in the same manner as in Example 1 except that the glass cloth having a woven density of 25 mm (Arisawa Seisakusho) (94 mm × 100 mm) was replaced with two.

[Example 4]
Instead of splicing three glass cloths, the weft density is 16/25 mm per unit dimension in the central end region and both end band regions described above while keeping the weft spacing equal. A sliding sheet D according to Example 1 except that a glass cloth woven in the order of 42 woven yarns per dimension / 25 mm woven density and 16 woven yarns per unit dimension / 25 mm woven density was used. Was made.

[Example 5]
Three glass cloths, one glass cloth (Arisawa Seisakusho) (94 mm × 100 mm) having a weaving density of 25 warp / 25 mm per unit dimension and 16 warps per unit dimension / A sliding sheet E was produced in the same manner as in Example 1 except that the glass cloth having a woven density of 25 mm (Arisawa Seisakusho) (94 mm × 100 mm) was replaced with two.

[Example 6]
Three glass cloths each have one glass cloth (Arisawa Seisakusho) (94 mm × 100 mm) having a weaving density of 55 warps per unit dimension / 16 mm, and 16 warps per unit dimension / A sliding sheet F was produced in the same manner as in Example 1 except that the glass cloth having a woven density of 25 mm (manufactured by Arisawa Seisakusho) (94 mm × 100 mm) was replaced with two.

[Example 7]
Three glass cloths each have a warp density of 42 pieces / 25 mm per unit dimension and one glass cloth (Arisawa Seisakusho) (94 mm × 100 mm), and 5 warps per unit dimension / A sliding sheet G was produced in the same manner as in Example 1 except that the glass cloth having a woven density of 25 mm (Arisawa Seisakusho) (94 mm × 100 mm) was replaced with two.

[Example 8]
Three glass cloths each have a warp density of 42/25 mm per unit dimension and one glass cloth (Arisawa Seisakusho) (94 mm × 100 mm), and 35 warps per unit dimension / A sliding sheet H was produced in the same manner as in Example 1 except that the glass cloth having a woven density of 25 mm (Arisawa Seisakusho) (94 mm × 100 mm) was replaced with two.

[Comparative Example 1]
Except that all three glass cloths were replaced with glass cloth having a weaving density of 42 warps per unit size / 25 mm (Arisawa Seisakusho) (94 mm × 100 mm), sliding was performed according to Example 1. A moving sheet I was prepared.

[Comparative Example 2]
Three glass cloths each have two glass cloths (94 mm × 100 mm) having a weaving density of 46 warps / 25 mm per unit dimension and 16 warps per unit dimension / 94 mm × 100 mm. Glass cloth having a woven density of 25 mm (Arisawa Seisakusho) (94 mm x 100 mm) is replaced with one piece, warp density per unit dimension is 42/25 mm, woven density is 16/25 mm, per unit dimension A sliding sheet J was produced in the same manner as in Example 1 except that the warp yarns were joined in the order of 42/25 mm woven density.

[Evaluation method]
The following measurements were performed on the sliding sheets of Examples and Comparative Examples. The evaluation results are shown in Table 1.

In the fixing device shown in FIG. 1, the obtained sliding sheet is installed, the pressure of the pressing pad is set to 2.5 kg / cm ² , the fixing speed of the fixing belt is set to 255 mm / s, and lubricating oil (KF-968, (Shin-Etsu Silicone Co., Ltd.) 0.5ml is applied to the inner surface of the belt, and the pressure belt is driven to rotate the fixing belt made of a non-tensioned polyimide (inner diameter Φ30mm, length 400mm). The temperature of the nip region constituted by the pressure roll and the pressure roll is set to 200 ° C., the pressure roll is rotated for 200 hours, and the convex height of the end band region of the sliding sheet after 200 hours is digitally Measurement was performed using a microscope “VHX-1000” (manufactured by Keyence Corporation) and Surfcom (manufactured by Tokyo Seimitsu Corporation). The convex height of the end band region of the sliding sheet before installation on the fixing device was measured in the same manner. Moreover, the convex height after 200 hours was set to 7 μm or more.

  As an application example of the present invention, there is application to an image forming apparatus such as a copying machine or a printer using an electrophotographic system.

  1Y, 1M, 1C, 1K Image forming unit, 10 Primary transfer unit, 11 Photosensitive drum, 12 Charger, 13 Laser exposure unit, 14 Developer, 15 Intermediate transfer belt, 16 Primary transfer roll, 17 Drum cleaner, 20 2 Next transfer section, 22 Secondary transfer roll, 25 Backup roll, 26 Feed roll, 31 Drive roll, 32 Support roll, 33 Tension roll, 34 Cleaning backup roll, 35 Intermediate transfer belt cleaner, 40 Control section, 43 Image density sensor, DESCRIPTION OF SYMBOLS 50 Recording medium accommodating part, 51 Pickup roll, 52 Conveyance roll, 53 Conveyance chute, 55 Conveyance belt, 56 Fixing inlet guide, 60 Fixing device, 61 Fixing belt, 62 Pressure roll, 63 Belt guide member, 64 Press pad, 65 Holder, 66 Woven cloth base , 67 Lubricant application member, 68 Sliding sheet, 69 Lubricating coating layer, 70 Peeling auxiliary member, 71 Peeling baffle, 72 Baffle holder, 85 Magnetic field generation unit, 100 Image forming apparatus, 300, 302 Glass cloth, 400 Assembly 621 Core, 622 Rubber layer, 623 Surface layer, 851 Excitation coil, 852 Coil support member, 853 Excitation circuit.

Claims (4)

A woven fabric substrate having a woven density distribution in a direction intersecting the sliding direction;
A coating layer provided on the surface of the woven fabric substrate,
The sliding sheet characterized in that the woven fabric base material has a woven density in a central band region along a sliding direction higher than a woven density in both end band regions sandwiching the central band region. The woven fabric base is formed of a plain weave,
Both end band regions sandwiching the central band region, wherein the weave density of the central band region along the sliding direction is 30/25 mm or more and 50/25 mm or less per unit dimension in the direction intersecting the sliding direction The sliding according to claim 1, wherein the weaving density has a weaving density distribution of 10/25 mm or more and 30/25 mm or less per unit dimension in a direction intersecting the sliding direction. Sheet. A rotatable rotating member;
A rotation that is arranged in pressure contact with the rotating member and fixes the unfixed toner image on the recording medium by sandwiching a recording medium carrying an unfixed toner image in a nip formed between the rotating member and the rotating member. A possible film tubular body,
The sliding sheet according to claim 1 or 2, interposed between the film tubular body and the pressing member,
A fixing device. A latent image forming unit for forming a latent image on the image holding member; a developing unit for developing the latent image using a developer for developing an electrostatic image; and a developed toner image via or via an intermediate transfer member. An image forming apparatus including a transfer unit that transfers the toner image on the transfer body, and a fixing unit that fixes the toner image on the transfer body,
An image forming apparatus, wherein the fixing unit includes the fixing device according to claim 3.