Fixing device

Abstract

The present invention provides a fixing device that provides a small initial drive torque when starting the drive of a stationary fixing rotating body. [Solution] A fixing device comprising a belt-shaped fixing rotating body and a friction-receiving member disposed inside the fixing rotating body and having a friction-receiving surface that is rubbed against the inner circumferential surface of the fixing rotating body via a lubricant, wherein the lubricant is silicone oil, the friction-receiving member has a friction-receiving layer having the friction-receiving surface, the friction-receiving surface has surface protrusions, the friction-receiving layer contains a thermoplastic resin and a resin having a polysiloxane structure, and in each of the observation area X of 25 μm × 25 μm on the surface of the surface protrusions and the observation area Y of the friction-receiving layer in the thickness direction of the friction-receiving layer, with a width of 5 μm from the surface of the friction-receiving layer in contact with the substrate protrusions, the area ratio occupied by the resin having a polysiloxane structure is within a specific range.

Description

Technical Field

[0001] The present disclosure relates to a fixing device that fixes a toner image carried on a recording material to the recording material.

Background Art

[0002] In recent years, the on-demand printing market has been expanding, where commercial printed materials such as catalogs, posters, and pamphlets are printed according to the required number of copies, and various invoices and direct mails are continuously printed while partially changing the printed content for each customer. In recent years, electrophotographic image forming apparatuses responsible for on-demand printing have been required to further increase the printing speed.

[0003] In order to achieve a further increase in the printing speed, it is necessary to apply sufficient energy to an unfixed toner image on a recording material such as paper in a short time. As one method for this, the use of a fixing device with a wide fixing nip that can apply energy to the unfixed toner image for a relatively longer time can be cited. Here, the width of the fixing nip refers to the length of the contact portion between the fixing rotating body for heating the unfixed toner image and the pressing rotating body disposed opposite to the fixing rotating body in the direction along the conveyance direction of the recording material. Hereinafter, a fixing device with a wide fixing nip may also be referred to as a fixing device with a wide nip.

[0004] In such a fixing device with a wide nip, in order to ensure excellent image quality, it is important to more reliably prevent slip between the fixing rotating body and the recording material, and slip between the pressing rotating body and the recording material.

[0005] Further, as the fixing device, (i) An endless rotatable belt (fixing rotating body), (ii) A pressing member that forms a nip portion for sandwiching and conveying the recording material between the belt, (iii) In the nip portion, a rubbed member that slides against the inner peripheral surface of the belt via a lubricant, Devices equipped with this are known. The lubricant is used to stabilize the sliding between the inner surface of the belt and the friction-ridden member. If the lubricant is no longer present in the nip portion, the rotation of the belt becomes unstable, wear occurs on the inner surface of the belt and the friction-ridden member, and the lifespan of the device is shortened.

[0006] In such a fixing device, in order to suppress the aforementioned slippage, it is necessary to sufficiently reduce the sliding resistance between the friction-bearing member and the inner surface of the belt member with respect to the friction force between the recording material and the belt member and the friction force between the recording material and the pressurizing member.

[0007] Patent Document 1 discloses the use of a friction-bearing member in the fixing device configuration described above, which has a base layer and a friction-bearing layer provided to cover the surface of the base layer that rubs against the belt. It is described that the base layer has a plurality of protrusions formed on the side that rubs against the belt, projecting toward the inner circumferential surface of the belt. It is also described that the surface shape of the friction-bearing layer formed at the tips of the plurality of protrusions is a curved surface with a radius of curvature R of 300 to 850 μm. Furthermore, Patent Document 1 states that by using the friction-bearing member described above, the sliding resistance between the friction-bearing member and the inner circumferential surface of the belt can be reduced. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2023-125025 [Overview of the project] [Problems that the invention aims to solve]

[0009] According to the inventors' studies, the fixing device described in Patent Document 1 was effective in reducing the sliding resistance between the abraded member and the inner surface of the belt member to a certain extent. However, it was found that when starting the drive (rotation) of the fixing rotating body from a stationary state, the sliding resistance between the abraded member and the inner surface of the belt member increased, and slippage between the fixing rotating body and the recording material, as well as slippage between the pressing rotating body and the recording material, may occur. Furthermore, due to the increase in the above-mentioned sliding resistance, there was a tendency for the initial drive torque of the fixing device to increase in order to start the rotation of the fixing rotating body from a stationary state.

[0010] Therefore, at least one aspect of this disclosure is aimed at providing a fixing device that has a small initial drive torque when starting to drive a stationary fixing rotating body. [Means for solving the problem]

[0011] A fixing device relating to one aspect of this disclosure is: A fixing device for fixing an unfixed toner image supported on a recording material to the recording material, the fixing device comprising: a belt-shaped fixing rotating body; a pressing rotating body positioned opposite the fixing rotating body and forming a nip portion together with the fixing rotating body; a friction-bearing member positioned inside the fixing rotating body and having a friction-bearing surface that is rubbed against the inner circumferential surface of the fixing rotating body via a lubricant; a pressing member positioned inside the fixing rotating body and pressing the fixing rotating body against the pressing rotating body via the friction-bearing member; and a heater for heating the fixing rotating body, wherein the lubricant is silicone oil, and the friction-bearing member comprises a metal substrate and a friction-bearing layer covering the surface of the metal substrate and having the friction-bearing surface. The surface of the metal substrate on the side where the abraded layer is present has a plurality of substrate protrusions, and the abraded surface has surface protrusions formed by the substrate protrusions and the abraded layer covering the substrate protrusions, and the abraded layer contains a thermoplastic resin and a resin having a polysiloxane structure, and in a 25 μm × 25 μm observation area X on the surface of the surface protrusions, the area ratio A occupied by the resin having a polysiloxane structure is 5% or more and 50% or less, and in a cross-section in the thickness direction of the abraded layer, in an observation area Y of the abraded layer with a width of 5 μm from the surface of the abraded layer in contact with the substrate protrusions, the area ratio B occupied by the resin having a polysiloxane structure is 3% or less. [Effects of the Invention]

[0012] According to at least one aspect of this disclosure, a fixing device can be obtained that has a small initial drive torque when starting to drive a stationary fixing rotating body. [Brief explanation of the drawing]

[0013] [Figure 1] This is a cross-sectional view showing the schematic configuration of an electrophotographic image forming apparatus according to one aspect of the present disclosure. [Figure 2] This is a cross-sectional view showing the schematic configuration of a fixing device according to one aspect of this disclosure. [Figure 3] (a) is an enlarged cross-sectional view of the vicinity of the nip portion of the fixing device shown in Figure 2, and (b) is a top view of the abrasion member as seen from the side where the fixing rotating body is positioned. [Figure 4] This is an enlarged cross-sectional view of a part of a member to be rubbed according to one aspect of the present disclosure. [Figure 5] This is a schematic diagram showing a cross-section in the thickness direction of a friction-resistant member according to one aspect of the present disclosure. [Figure 6] This is a schematic diagram illustrating the structure of a friction-resistant member manufactured by a method for manufacturing a friction-resistant member according to one aspect of the present disclosure. [Modes for carrying out the invention]

[0014] In this specification, descriptions of numerical ranges such as "XX or greater and YY or less" or "XX to YY" mean a numerical range that includes its endpoints, the lower and upper limits. Furthermore, when numerical ranges are described in steps, the upper and lower limits of each numerical range can be any combination. In this disclosure, for example, a description such as "at least one selected from the group consisting of XX, YY, and ZZ" means any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ.

[0015] Normally, a lubricant such as silicone oil is interposed between the inner surface of the fixing rotating body and the friction surface of the friction-worked member to provide good sliding properties. However, when starting the movement of a stationary fixing rotating body, the lubricant may be pushed out from the contact area between the inner surface of the fixing rotating body and the friction surface of the friction-worked member due to physical shocks during movement. This is thought to result in a very large sliding resistance between the friction surface of the friction-worked member and the inner surface of the fixing rotating body.

[0016] Therefore, as a result of further studies by the present inventors, it has been found that according to a rubbing member having the following configuration, a lubricant can be present at the contact portion between the rubbing member and the inner peripheral surface of the fixing belt even at the start of driving of the fixing rotating body. As a result, it has been found that an increase in the sliding resistance between the rubbed surface of the rubbing member and the inner peripheral surface of the fixing rotating body can be prevented, and slippage between the fixing rotating body and the recording material, as well as slippage between the pressing rotating body and the recording material, can be suppressed from the initial stage of image formation. In addition, it has been found that an increase in the initial driving torque can be suppressed.

[0017] <Configuration> The rubbing member according to the present disclosure includes a metal base material and a rubbed layer that is a resin layer covering the surface of the metal base material. A plurality of base material convex portions are present on the surface of the metal base material on the side where the rubbed layer is present, and surface convex portions formed by the base material convex portions and the rubbed layer covering the base material convex portions are present on the surface of the rubbing member on the side having the base material convex portions. Further, the rubbed layer on the surface of the surface convex portion contains a resin having a thermoplastic resin and a polysiloxane structure. In an observation region X of 25 μm × 25 μm on the surface of the surface convex portion, the area ratio A of the resin having a polysiloxane structure observed within the observation region X is 5% or more and 50% or less. Also, in an observation region Y of the rubbed layer having a width of 5 μm from the surface of the rubbed layer in contact with the base material convex portion in the cross section in the thickness direction of the rubbed layer, the area ratio B of the resin having a polysiloxane structure observed within the observation region Y is 3% or less.

[0018] Hereinafter, an aspect of the fixing device according to the present disclosure will be described with reference to the drawings. FIGS. 2 and 3 are schematic cross-sectional views for explaining a fixing device 8 according to an aspect of the present disclosure. In FIG. 2, the X direction indicates the conveyance direction of the recording material P, the Y direction indicates the direction intersecting the conveyance direction of the recording material P (the depth direction of the paper surface), and the Z direction indicates the pressing direction in which the recording material P is pressed at the nip portion N. In the present embodiment, the X direction, the Y direction, and the Z direction are directions orthogonal to each other. FIG. 3 is an enlarged cross-sectional view of a region NA including the nip portion N surrounded by a dotted line in FIG. 2.

[0019] The fixing device 8 includes at least a fixing rotating body 301, a stay 302, a pressure pad (hereinafter also simply referred to as "pad") 303, a friction member 304, a pressure rotating body 305, a heater 306, a heating roller 307, and a thermistor 308. The fixing rotating body 301 can be, for example, a belt-shaped endless structure. The pressurizing rotating body 305 is positioned opposite the fixing rotating body 301 and together with the fixing rotating body 301 forms a nip section N that grips and conveys the recording material P.

[0020] The friction-bearing member 304 is positioned inside the fixing rotating body and is rubbed against the inner circumferential surface of the fixing rotating body 301 at the nip portion N via the lubricant 309. The pad 303, acting as a backup member, is positioned inside the fixing rotating body 301 so as to sandwich the abraded member 304 and the fixing rotating body 301 between the pressing rotating body 305, thereby backing up the abraded member 304. The friction-bearing member 304 is positioned to cover the side of the pad 303 facing the fixing rotating body 301. The friction-bearing member 304 is attached to cover at least the position corresponding to the nip portion N of the pad 303. The friction-bearing member 304 may be provided on the entire surface of the side of the pad 303 facing the fixing rotating body 301, or it may be attached only to the position corresponding to the nip portion N.

[0021] The stay 302 is positioned inside the fixing rotating body 301, on the opposite side of the nip portion N, with the pad 303 in between, and supports the pad 303. The heating roller 307 is positioned inside the fixing rotating body 301 so as to support the fixing rotating body 301 and heats the fixing rotating body 301. The thermistor 308, acting as a temperature sensing element, detects the temperature of the fixing rotating body 301.

[0022] The fixing rotating body 301 has thermal conductivity and heat resistance, and is a thin-walled cylindrical shape. In this embodiment, as shown in Figure 3, the fixing rotating body 301 has a base layer 301a, an elastic layer 301b covering the outer surface of the base layer 301a, and a release layer 301c covering the outer surface of the elastic layer 301b. The base layer 301a can be, for example, a polyimide resin (PI) layer with a thickness of 80 μm. The elastic layer 301b can be, for example, a layer containing silicone rubber with a thickness of 300 μm. The release layer 301c can be, for example, a fluororesin layer with a thickness of 30 μm. Examples of fluororesins constituting the fluororesin layer include, for example, tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin (PFA) and FEP.

[0023] The fixing rotating body 301 is tensioned by the pad 303 and the heating roller 307. The outer diameter of the fixing rotating body 301 can be, for example, 150 mm. The pad 303 is positioned inside the fixing rotating body 301, facing the pressing rotating body 305 with the fixing rotating body 301 in between, and forms a nip portion N that grips and conveys the recording material P between the fixing rotating body 301 and the pressing rotating body 305. In this embodiment, the pad 303 is a substantially plate-shaped member that is long along the width direction of the fixing rotating body 301 (the longitudinal direction intersecting the rotation direction of the fixing rotating body 301, and the rotation axis direction of the heating roller 307). The nip portion N is formed when the pad 303 is pressed by the pressing rotating body 305 with the fixing rotating body 301 in between. The material of the pad 303 can be, for example, LCP (liquid crystal polymer) resin. A friction-bearing member 304 and a lubricant 309 are interposed between the pad 303 and the fixing rotating body 301. Details of the friction-bearing member 304 will be described later.

[0024] The pad 303 is supported by a stay 302, which acts as a support member positioned inside the fixing rotating body 301. The stay 302 is positioned on the opposite side of the pad 303 from the pressurizing rotating body 305 and supports the pad 303. The stay 302 is a rigid reinforcing member that is long along the longitudinal direction of the fixing rotating body 301 and contacts the pad 303 to back it up. In other words, when the pad 303 is pressed by the pressurizing rotating body 305, the stay 302 provides strength to the pad 303 and ensures the applied pressure at the nip portion N. That is, the stay 302 and the pad 303 are each positioned inside the fixing rotating body 301 and function as pressing members that press the fixing rotating body 301 against the pressurizing rotating body 305 via the friction-bearing member 304.

[0025] The stay 302 is made of a metal such as stainless steel, and its cross-section (transverse plane) perpendicular to the longitudinal direction of the stay 302, which intersects with the rotational direction of the anchoring rotating body 301, is substantially rectangular. For example, it is preferable to ensure strength by using a 3mm thick drawn stainless steel (e.g., SUS304) for the stay 302 and forming its cross-section into a substantially rectangular hollow shape. Alternatively, the stay 302 may be formed by combining multiple sheet metal pieces and fixing them to each other by welding or other means so that the cross-section is substantially rectangular. Furthermore, the material of the stay 302 is not limited to stainless steel as long as strength can be ensured.

[0026] The lubricant 309 only needs to be interposed between the fixing rotating body 301 and the friction-ridden member 304, and is preferably a silicone oil with a siloxane group as its main chain. Silicone oil has a high affinity for the inner circumferential surface of the fixing rotating body 301, and the fact that the lubricant 309 is a silicone oil makes it easier to suppress the increase in driving torque. The viscosity of the lubricant 309 is preferably 300 cSt or more and 15,000 cSt or less at room temperature. If the viscosity of the lubricant 309 is 300 cSt or more at room temperature, leakage from the ends can be suppressed during the process of circulating on the inner surface of the fixing rotating body 301, and it can function stably. If the viscosity of the lubricant 309 is 15,000 cSt or less at room temperature, it can be stably interposed between the friction surface of the friction layer 304c and the fixing rotating body 301. In addition, by not having too high a viscosity, fluidity can be maintained, and unevenness in the amount of lubricant 309 from region to region of the friction surface can be suppressed, and it can perform its function stably.

[0027] Lubricant 309 may contain other components besides oil. Other components include thermal conductive agents, antioxidants, and surfactants.

[0028] The heating roller 307 is positioned inside the fixing rotating body 301 and, together with the pad 303, tensions the fixing rotating body 301. The heating roller 307 is a cylindrical member made of a metal such as aluminum or stainless steel, and a heater 306 for heating the fixing rotating body 301 is disposed inside it. The heater 306 can be any heater capable of heating the fixing rotating body 301, such as a halogen heater or a carbon heater. The heating roller 307 is heated to a predetermined temperature by the heater 306, and the fixing rotating body 301 is heated by the heated heating roller 307.

[0029] The heating roller 307 has a pivot point at one end or near the center in the longitudinal direction, and rotates in contact with the fixing rotating body 301, thereby generating a tension difference before and after the contact point between the fixing rotating body 301 and the heating roller 307. In other words, the heating roller 307 also acts as a steering roller that controls the position of the fixing rotating body 301 in the main scanning direction. Furthermore, the heating roller 307 is biased by a spring supported by a frame (not shown), and also acts as a tension roller that applies a predetermined tension to the fixing rotating body 301.

[0030] In this embodiment, the heating roller 307 is formed, for example, from a stainless steel pipe with a thickness of 1 mm. When a halogen heater is used as the heater 306, there may be only one halogen heater, but it is preferable to use multiple heaters in consideration of controlling the temperature distribution in the longitudinal direction (rotation axis direction) of the heating roller 307. Multiple halogen heaters have different light distributions in the longitudinal direction, and the lighting ratio is controlled according to the size of the recording material P. In this embodiment, three halogen heaters are arranged as the heater 306.

[0031] The fixing rotating body 301 is heated by a heating roller 307 heated by a heater 306, and controlled to a predetermined target temperature according to the type of recording material P based on the temperature detected by a thermistor 308. The thermistor 308 is positioned opposite the outer circumferential surface of the fixing rotating body 301 near the center, through which recording materials P of all sizes that can be fixed by the fixing device 8 pass, in the width direction of the fixing rotating body 301. The thermistor 308 detects the temperature of the fixing rotating body 301, and the control unit 30 (see Figure 1) controls the power supplied to the heater 306 so that the temperature detected by the thermistor 308 becomes the target temperature. The thermistor 308 may be a non-contact type sensor positioned close to the outer circumferential surface of the fixing rotating body 301, or it may be a contact type sensor positioned in contact with the outer circumferential surface of the fixing rotating body 301.

[0032] The pressurizing rotating body 305 rotates in contact with the outer circumferential surface of the fixing rotating body 301, and also serves as a drive roller that imparts driving force to the fixing rotating body 301. Alternatively, the heating roller 307 can be driven by a motor or other drive source (not shown) to serve as the drive roller for the fixing rotating body 301. In other words, the drive roller for the fixing rotating body 301 can be at least one selected from the group consisting of the pressurizing rotating body 305 and the heating roller 307.

[0033] The pressing rotating body 305 includes, for example, a core metal (shaft) 305c, an elastic layer 305b provided on the outer circumference of the core metal 305c, and a release layer 305a covering its outer circumference.

[0034] The core metal 305c can be, for example, a stainless steel roller with a diameter of 72 mm. The elastic layer 305b can be, for example, a conductive elastic layer containing silicone rubber with a thickness of 8 mm. Furthermore, the release layer 305a can be, for example, a fluororesin layer with a thickness of 100 μm. An example of the fluororesin constituting the fluororesin layer is, for example, tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin (PFA).

[0035] The pressurizing rotating body 305 is rotatably supported by the frame (not shown) of the fixing device 8, and a gear (not shown) is fixed to one end of it. The pressurizing rotating body is connected to a drive source (not shown), such as a motor, via this gear and driven by it.

[0036] The fixing device 8 grips the recording material P, which carries the unfixed toner image, in a nip section N formed between the fixing rotating body 301 and the pressurizing rotating body 305, and heats the unfixed toner image while transporting it. In this way, the fixing device 8 fixes the toner to the recording material P while gripping and transporting it. Therefore, it is necessary to have both the function of applying heat and pressure and the function of transporting the recording material P. The pressurizing rotating body 305 is pressurized against the abrasion member 304 via the fixing rotating body 301 by a drive source (not shown).

[0037] The pressure (F1) applied to the nip portion N during image formation, that is, the load applied to the pad 303 and the pressurizing rotating body 305, may specifically be, for example, 1600 N. Furthermore, the width of the nip portion N in the X direction (the direction in which the recording material P is transported) may specifically be, for example, 24.5 mm, and the width in the Y direction (the width direction of the recording material P) may specifically be, for example, 326 mm.

[0038] The length (nip width) of the nip section N in the transport direction (X direction) is determined by the pressure (F1) applied when the abrasion member 304 is pressed against the pressurizing rotating body 305 via the fixing rotating body 301. The pressure (F1) in the nip section N is not particularly limited, but it is preferable to apply enough force to the fixing rotating body 301 to sufficiently press against the pressurizing rotating body so that slippage does not occur between the recording material P passing through the nip section N and the fixing rotating body and the pressurizing rotating body. For example, it is preferable to set the load value applied to the pad 303 and the pressurizing rotating body 305 to 900N or more, and more particularly to 1600N or more.

[0039] [Abrasion-resistant component] The friction-bearing member 304 will be explained using Figures 3 and 4. Figure 3(a) is an enlarged cross-sectional view of the region NA including the nip portion N, enclosed by a dotted line in Figure 2, and (b) is a top view of the surface on which the abraded member 304 contacts the fixing rotating body 301, as seen from the side on which the fixing rotating body 301 is positioned. Figure 4 is a partially enlarged cross-sectional view of the abraded member 304. Here, the abraded member 304 is fixed to the stay 302 with screws (not shown) via the pad 303. In this embodiment, the abraded member 304 and the pad 303 are separate components, but they may be integrated.

[0040] The abraded member 304 comprises a base material 304a having a plurality of base material protrusions 405, and an abraded layer 304b covering the base material 304a. The abraded layer 304b has surface protrusions 407 corresponding to the base material protrusions 405. The abraded layer 304b may be bonded to the surface of the base material 304a with an adhesive layer (not shown).

[0041] <Base material> The base material 304a preferably has sufficient strength and heat resistance to prevent deformation when a pressing force is applied to the fixing rotating body 301 from the pressing rotating body 305. For this reason, the material of the base material 304a is preferably metal, specifically stainless steel, aluminum, aluminum alloy, nickel, nickel alloy, etc. Specifically, for example, stainless steel with a thickness of 1.3 mm (e.g., SUS304, etc.) can be used. Here, the thickness of the base layer refers to the thickness of the portion of the base material without the protrusions 405.

[0042] Multiple base material protrusions 405 constitute a part of the base material 304a. From the viewpoint of equalizing the pressure in the nip section N, it is preferable that multiple base material protrusions 405 are arranged in a direction along the transport direction (X direction) of the recording material P in the nip section N, and in a direction intersecting the transport direction (Y direction). The base material protrusions 405 are formed with a certain inter-shape distance (d), reducing sliding resistance by reducing the contact area with the fixing rotating body 301. Here, the inter-shape distance (d) is the distance in the X and Y directions between the centers (geometric centers) of the upper surfaces (the surfaces closest to the fixing rotating body 301 via the lubricant) of two adjacent base material protrusions 405. The inter-shape distance (d) is preferably 0.5 mm or more and 2.5 mm or less.

[0043] The shape of each of the multiple base material protrusions 405 is preferably a frustoconical shape. The frustoconical shape is not particularly limited as long as it can hold a sufficient amount of lubricant 309 to contribute to reducing the starting torque of the fixing device, but it is preferable that the diameter of the base is larger than the diameter of the top surface. The height is also not particularly specified, but it is preferably 100 μm or more in order to hold a sufficient amount of lubricant 309, and the angle of the hypotenuse is also not particularly specified, but it is preferably 30° or more.

[0044] The method for manufacturing the substrate 304a having multiple substrate protrusions 405 is not particularly limited, but examples include chemical etching and press working.

[0045] <Rubbing layer> The abrasion-resistant layer 304b covers the surface of the base material 304a on the side where the base material protrusions 405 are located. The abrasion-resistant layer 304b has a surface protrusion 407 on the surface opposite to the side facing the base material 304a (the abrasion-resistant surface), corresponding to the base material protrusions 405. Here, the surface protrusion 407 corresponding to the base material protrusions 405 refers to the protrusions formed on the abrasion-resistant surface of the abrasion-resistant layer 304b by covering the surface of the base material protrusions 405.

[0046] The upper surface of the surface protrusion 407 (the surface closest to the fixing rotating body 301 via the lubricant) has a size of at least 25 μm × 25 μm. The shape of each surface protrusion 407 is preferably a frustoconical shape, and the upper surface of the frustoconical surface protrusion 407 is preferably 200 μm or more and 600 μm or less in diameter.

[0047] The surface protrusions 407 are located on the surface (abrasion surface) of the abrasion layer 304b of the abrasion member 304 that faces the inner circumferential surface of the fixing rotating body 301. Therefore, the presence of lubricant 309 on the surface protrusions 407 reduces the contact area between the abrasion member 304 and the inner circumferential surface of the fixing rotating body 301, thereby reducing the sliding resistance between the abrasion member 304 and the inner circumferential surface of the fixing rotating body 301.

[0048] The abrasion-resistant layer 304b is composed of a thermoplastic resin and a resin having a polysiloxane structure. As the thermoplastic resin, a resin that has excellent wear resistance and also excellent sliding properties with respect to the inner circumferential surface of the fixing rotating body 301 is preferred. Specifically, for example, the thermoplastic resin may be polyetheretherketone (PEEK). The content of the thermoplastic resin in the friction layer 304b is preferably 70% by mass or more in order to ensure wear resistance.

[0049] Resins having a polysiloxane structure have a high affinity for silicone oil as a lubricant 309, and contribute to the stable presence of the lubricant 309 on the abraded surface of the abraded layer 304b. Preferably, the resin having a polysiloxane structure is a silicone resin that has a particularly high affinity for silicone oil. When starting the operation of the fixing device from a stationary state, the abraded member 304 is pressed against the inner circumferential surface of the fixing rotating body 301. Even in such cases, the presence of the resin having a polysiloxane structure on the surface protrusions 407 of the abraded layer 304b allows the lubricant 309 to stably exist between the surface protrusions 407 and the inner circumferential surface of the fixing rotating body 301. As a result, an increase in the starting torque of the fixing device can be prevented.

[0050] Figure 5 is a schematic diagram showing a cross-section in the thickness direction of the abraded member 304. As shown in Figure 5, in the abrasion-resistant layer 304b covering the surface of the substrate protrusion 405, the proportion of resin 501 having a polysiloxane structure differs depending on its position in the thickness direction. With respect to this proportion of resin 501 having a polysiloxane structure, the abrasion-resistant member 304 satisfies the following requirement 1.

[0051] <Requirement 1> In an observation area X of 25 μm × 25 μm on the surface of the surface protrusion 407, the area ratio A occupied by the resin 501 having the polysiloxane structure is 5% or more and 50% or less. In an observation area Y of the abraded layer 304b with a width of 5 μm from the surface of the abraded layer 304b that is in contact with the substrate protrusion 405, the area ratio B occupied by the resin 501 having the polysiloxane structure is 3% or less.

[0052] The area ratio A is calculated by the following method. The surface of the abraded layer 304b of the abraded member 304 is observed with a scanning electron microscope, and an SEM image (magnification 5000x) of the observation area X of 25 μm × 25 μm is obtained. The resolution is set to 717 pixels vertically and 986 pixels horizontally so that the resin having a polysiloxane structure can be recognized. The obtained SEM image is converted into an 8-bit grayscale image using image processing software (product name: Image-J, manufactured by the National Institutes of Health (NIH)). After applying a median filter to the obtained grayscale image, binarization is performed using the above image processing software to obtain a binarized image. The binarization process uses Otsu's method (see IEEE TRANSACTIONS ON SYSTEMS, MAN, AND CYBERNETICS, VOL.SMC-9, NO.1, JANUARY 1979, PP.62-66) to distinguish between portions of the SEM image corresponding to polysiloxane resin and portions corresponding to thermoplastic resin. Then, the ratio of the number of pixels in the portion corresponding to polysiloxane resin to the total number of pixels in the image is calculated.

[0053] In this disclosure, observation areas are set at any 10 locations on the surface protrusions of the sliding layer, and the arithmetic mean of the ratios calculated from each observation area is defined as the area ratio A. Note that each observation area is positioned so as not to overlap with others. The specific method will be explained in the embodiments described later.

[0054] Area ratio B is calculated as follows: A cross-sectional sample showing the thickness direction of the abraded member 304 is cut out from the abraded member 304 using a cryo-ultramicrotome (manufactured by Leica Microsystems).

[0055] Next, an arbitrary cross-section of the abrasion layer 304b with a width of 5 μm from the surface of the abrasion layer 304b in contact with the substrate protrusion 405 is observed using a scanning electron microscope, and an SEM image of an observation area of ​​5 μm vertically × 11 μm horizontally is obtained. The resolution is set to 717 pixels vertically and 986 pixels vertically so that resins having a polysiloxane structure can be recognized. The obtained SEM image is binarized using numerical calculation software (product name: MATLAB®, manufactured by MathWorks Inc.) to obtain a binarized image. For the binarization process, Otsu's method is used to distinguish between the portion corresponding to the resin having a polysiloxane structure and the portion corresponding to the thermoplastic resin in the SEM image.

[0056] Then, the ratio of the number of pixels in the obtained binarized image that correspond to the resin having a polysiloxane structure to the total number of pixels in the image is calculated.

[0057] Perform the above operation at any three locations, and the arithmetic mean of these three ratios will be defined as area ratio B. The specific method will be explained in the example described later.

[0058] As shown in Figure 5, the formation of an abrasion-resistant layer 304b in which the resin 501 having a polysiloxane structure is abundant on the surface of the abrasion-resistant layer 304b and less abundant near the surface of the substrate protrusions 405 can be achieved by forming a coating film by spraying. Specifically, a resin solution in which the resin 501 having a polysiloxane structure is blended into a dispersion of thermoplastic resin is applied to the substrate protrusions 405 with a spray gun to form a coating film. After drying the coating film, the abrasion-resistant layer 304b is formed by firing at a temperature above the melting point of the thermoplastic resin, thereby creating a layer with different proportions of the resin 501 having a polysiloxane structure.

[0059] The mechanism by which the proportion of the polysiloxane-structured resin 501 in the thickness direction differs depending on the location is hypothesized as follows: During firing, the polysiloxane-structured resin 501 has a lower surface energy than the molten thermoplastic resin, and is therefore thought to rise to the surface of the abrasion-resistant layer 304b. Furthermore, studies have shown that more rise occurs with higher firing temperatures. With the above formation method, the abrasion-resistant layer 304b has a large amount of polysiloxane-structured resin 501 on its surface, and almost none near the surface of the substrate protrusion 405, thus achieving requirement 1.

[0060] The area ratio A calculated by the above method is 5% or more, preferably 10% or more. If the area ratio A is 5% or more, the resin 501 having a polysiloxane structure present on the surface protrusions 407 of the abrasion layer 304b can be secured, and sufficient lubricant 309 can be present to reduce the starting torque. Alternatively, the area ratio A may be 50% or less. If the area ratio A is 50% or less, the proportion of thermoplastic resin with excellent wear resistance will not become too small, and wear resistance can be ensured.

[0061] Furthermore, the area ratio B calculated by the above method is 3% or less, preferably 1% or less. If the area ratio B is 3% or less, it is possible to suppress the decrease in adhesion during long-term repeated use, starting from the resin 501 having a polysiloxane structure present near the surface of the substrate protrusion 405.

[0062] <Method for manufacturing a friction-applied component> Examples of methods for manufacturing a friction-scratched member according to this disclosure include a method having the following steps A to B.

[0063] Step A: A substrate 304a having a substrate protrusion 405 on one side of its surface is prepared. As described above, such a substrate can be manufactured, for example, by chemical etching or press working.

[0064] Step B: The abrasion-resistant layer 304b is formed on the surface of the substrate 304a prepared in Step A, on the side where the substrate protrusion 405 is formed. The abrasion-resistant layer 304b is formed by the method described above. A dispersion of the resin constituting the abrasion-resistant layer 304b is applied to the surface to form a coating film of the dispersion, and subsequently the abrasion-resistant layer 304b is formed by drying and firing the coating film.

[0065] Figure 6 is a schematic diagram illustrating the configuration of the abrasion-resistant member 304 manufactured by the method described above. In step B, the thickness L-601 of the abrasion layer 304b other than the base material protrusions 405 of the base material 304a is not particularly limited. Preferably, the thickness L-601 is such that surface protrusions 407 corresponding to the base material protrusions 405 on the base material 304a are formed on the abrasion surface of the abrasion layer 304b. Specifically, for example, it is preferable that the thickness L-601 of the abrasion layer 304b is smaller than the height H-405 of the base material protrusions 405, i.e., height H-405 > thickness L-601. Furthermore, it is preferable that the abrasion layer 304b completely covers the base material protrusions 405 of the base material 304a. In addition, it is preferable that the average thickness L-602 of the abrasion layer 304b covering the base material protrusions 405 is, for example, 10 μm or more and 100 μm or less. Note that the thickness L-601 and the average thickness L-602 may be the same or different.

[0066] <Image forming apparatus> Hereinafter, an electrophotographic image forming apparatus (hereinafter also referred to as "image forming apparatus") according to one aspect of this disclosure will be described with reference to Figure 1. In the following description, an image forming apparatus capable of forming full-color images using an electrophotographic method having multiple electrophotographic photosensitive drums will be used as an example, but this disclosure is not limited to this and can be applied to various types of image forming apparatuses, monochrome image forming apparatuses, etc.

[0067] The full-color image forming apparatus 1 comprises an image reading unit 2 and the main body 3 of the image forming apparatus. The image reading unit 2 reads a document placed on the document glass 21. Light emitted from the light source 22 is reflected by the document and formed as an image on the CCD sensor 24 via optical system components 23 such as lenses. By scanning in the direction of the arrow, this optical system unit converts the document into a series of electrical signal data for each line. The image signal obtained by the CCD sensor 24 is sent to the main body 3 of the image forming apparatus, where the control unit 30 performs image processing according to each image forming unit, which will be described later. The control unit 30 also receives external input as an image signal from an external host device such as a print server.

[0068] The main body 3 of the image forming apparatus 1 is equipped with multiple image forming units Pa, Pb, Pc, and Pd, and each image forming unit performs image formation based on the image signal described above. That is, the image signal is converted into a laser beam controlled by PWM (pulse width modulation) by the control unit 30. The polygon scanner 31, which acts as an exposure device, scans the laser beam according to the image signal. The laser beam is then irradiated onto the photosensitive drums 200a to 200d, which serve as image carriers for each image forming unit Pa to Pd. The yellow (Y) image forming unit Pa, the magenta (M) image forming unit Pb, the cyan (C) image forming unit Pc, and the black (Bk) image forming unit Pd each form an image of the corresponding color. Since the image forming units Pa to Pd are substantially the same, the details of the yellow (Y) image forming unit Pa will be explained below, and the explanations of the other image forming units will be omitted. In the yellow (Y) image forming unit Pa, a toner image is formed on the surface of the photosensitive drum 200a based on the image signal, as described below.

[0069] The primary charger 201a charges the surface of the photosensitive drum 200a to a predetermined potential, preparing it for electrostatic latent image formation. An electrostatic latent image is formed on the surface of the photosensitive drum 200a, which has been charged to the predetermined potential, by a laser beam from the polygon scanner 31. The developer 202a develops the electrostatic latent image on the photosensitive drum 200a to form a toner image. The transfer roller 203a discharges from the back of the intermediate transfer belt 204, applying a primary transfer bias with the opposite polarity to the toner, and transfers the toner image on the photosensitive drum 200a onto the intermediate transfer belt 204. After the transfer, the surface of the photosensitive drum 200a is cleaned by the cleaner 207a.

[0070] Furthermore, the toner image on the intermediate transfer belt 204 is transported to the next image forming section, and the toner images of each color formed in the respective image forming sections are transferred sequentially in the order of Y, M, C, and Bk, forming a four-color image on its surface. The toner image that has passed through the black (Bk) image forming section Pd is secondary transferred to the recording material in the secondary transfer section, which consists of secondary transfer roller pairs 205 and 206, by applying a secondary transfer electric field with the opposite polarity to the toner image on the intermediate transfer belt 204. The recording material fed from the paper feed cassette 9 waits in the registration section 208, and then the timing is controlled to align the position of the recording material with the toner image on the intermediate transfer belt, and the recording material is transported from the registration section. After that, the toner image on the recording material is fixed to the recording material by the fixing device 8, which acts as an image heating device. After passing through the fixing device, the recording material is discharged from the machine. In the case of a double-sided job, once the transfer and fixing of the toner on the first image-forming surface (1st surface) is complete, the recording material is reversed by passing through a reversal section located inside the image-forming apparatus after fixing. Subsequently, the transfer and fixing of the toner on the second image-forming surface (2nd surface) is performed, and the recording material is discharged from the machine and stacked on the output tray 7. [Examples]

[0071] The present disclosure will be specifically described below using examples. However, the friction-scratched member and fixing device relating to the present disclosure are not limited to the configurations embodied in the following examples.

[0072] <Example A-1> (Preparation of the base material) A plate-shaped base material made of stainless steel (SUS304) was prepared, with a thickness of 1.3 mm, a width of 27.5 mm, and a length of 390 mm perpendicular to the width direction. Next, substrate protrusions were formed on one surface of the substrate by chemical etching. Each substrate protrusion was a frustoconical shape with a top diameter of 420 μm, a height of 250 μm, a hypotenuse angle of 65°, and a base diameter of 654 μm. Multiple substrate protrusions were formed such that the distance between the centers of the top surfaces in the X and Y directions of the substrate was 1.4 mm, resulting in 8750 substrate protrusions.

[0073] (Formation of the abrasion layer) A dispersion of polyether ether ketone (PEEK) (product name: VICOTE F817, manufactured by Victrex) was prepared. Next, the substrate prepared above was fitted into a core, and while rotating at 200 rpm, the dispersion was applied using a spray gun (product name: W-101, manufactured by Anest Iwata Corporation) to form a coating film of the dispersion. Next, the substrate with the coating film was placed in a heating furnace and heated at 120°C for 5 minutes to dry the coating film, and then heated at 400°C for 15 minutes to bake the coating film, forming an adhesive layer, which is the first PEEK resin layer, with a thickness of 2 μm.

[0074] Next, a dispersion of polyether ether ketone (PEEK) (product name: VICOTE F804, manufactured by Victrex) and silicone resin particles with an average particle size of 2.0 μm (product name: Tospar 120, manufactured by Momentive) were prepared. The PEEK and silicone resin were mixed in a mass ratio of 90:10, and the mixture was applied to the first PEEK resin layer formed above using a spray gun (product name: W-101, manufactured by Anest Iwata Corporation) to form a coating film. Then, the substrate with the coating film was placed in a heating furnace and heated at 120°C for 5 minutes to dry the coating film, and then heated at 400°C for 15 minutes to bake the coating film, forming a second PEEK resin layer with a thickness of 40 μm. In this way, a friction-resistant layer containing PEEK and silicone resin was formed on the surface of the substrate on the side where the protrusions were formed. Furthermore, the thickness of the abrasion-resistant layer covering the upper surface of the base material's protrusions was the same as the thickness of the abrasion-resistant layer covering the portion of the base material without protrusions. In this way, the abrasion-resistant member according to Example 1 was obtained. The obtained friction-resistant members were subjected to the following evaluations.

[0075] <Evaluation 1> Calculation of Area Ratios A and B (Measurement of area ratio A) A was calculated as follows:

[0076] The surface of the friction layer of the friction-resistant member was observed using a scanning electron microscope, and an SEM image (magnification 5000x) of an observation area X of 25 μm × 25 μm was acquired. The resolution was set to 717 pixels vertically and 986 pixels horizontally so that the silicone resin could be recognized. The acquired SEM image was converted to an 8-bit grayscale image using image processing software (product name: Image-J, manufactured by the National Institutes of Health (NIH)). After applying a median filter to the obtained grayscale image, binarization was performed using the same image processing software to obtain a binarized image. For the binarization process, the Otsu method (see IEEE TRANSACTIONS ON SYSTEMS, MAN, AND CYBERNETICS, VOL.SMC-9, NO.1, JANUARY 1979, PP.62-66) was used to distinguish between the portion corresponding to the silicone resin and the portion corresponding to PEEK in the SEM image. Next, the ratio of the number of pixels corresponding to the silicone particles in the obtained binarized image to the total number of pixels in the image was calculated. Here, observation areas were placed at 10 arbitrary locations on the surface protrusions of the sliding layer, and the arithmetic mean of the ratios calculated from each observation area was defined as area ratio A. Note that each observation area was placed in a position where they did not overlap with each other.

[0077] (Measurement of area ratio B) Furthermore, area ratio B was calculated as follows. A cross-sectional sample showing the thickness of the abraded material was cut from the abraded material using a cryo-ultramicrotome (manufactured by Leica Microsystems).

[0078] Next, an arbitrary cross-section of the abrasion layer with a width of 5 μm from the surface of the substrate protrusion was observed using a scanning electron microscope, and an SEM image of an observation area of ​​5 μm vertically × 11 μm horizontally was obtained. The resolution was set to 717 pixels vertically and 986 pixels vertically so that the silicone resin could be recognized. The obtained SEM image was binarized using numerical calculation software (product name: MATLAB®, manufactured by MathWorks Inc.) to obtain a binarized image. For the binarization process, Otsu's method was used to distinguish between the portion corresponding to the silicone resin and the portion corresponding to PEEK in the SEM image.

[0079] Then, the ratio of the number of pixels corresponding to the silicone particles in the obtained binarized image to the total number of pixels in the image was calculated. The above operation was performed at any three locations, and the arithmetic mean of these three ratios was taken as the area ratio B.

[0080] <Rating 2> <Torque Measurement> For this evaluation, a full-color electrophotographic image forming system (product name: imagePRESS V1000; manufactured by Canon Corporation) was used.

[0081] First, 50 ml of lubricant was applied to the surface of the friction-resistant member to be evaluated, specifically the side where the surface protrusions were formed. The lubricant used was silicone oil (product name: KF-96-3000CS, manufactured by Shin-Etsu Chemical Co., Ltd.). The kinematic viscosity of this lubricant at a temperature of 25°C was 3000 mm². 2 It is / s.

[0082] Next, the friction-bearing member fixed to the outer surface of the pad of the fixing device of the full-color electrophotographic image forming apparatus was removed, and the friction-bearing member to be evaluated, which had been prepared above and had lubricant applied to its surface, was attached. Then, the full-color electrophotographic image forming apparatus was turned on with the heater temperature set to 200°C, and the fixing rotor was driven to rotate by rotating the pressurizing rotor for 1 minute. After that, the power to the full-color electrophotographic image forming apparatus was turned off, and it was left in an environment with a temperature of 25°C for 24 hours. Subsequently, the power to the full-color electrophotographic image forming apparatus was turned on, and the maximum value of the on-axial torque of the pressurizing rotor (starting torque) when the pressurizing rotor started to rotate was measured.

[0083] <Example A-2> (Preparation of the base material) A plate-shaped base material made of stainless steel (SUS304) was prepared, with a thickness of 1.3 mm, a width of 27.5 mm, and a length of 390 mm perpendicular to the width direction.

[0084] Next, substrate protrusions were formed on one surface of the substrate by chemical etching. Each substrate protrusion was a frustoconical shape with a top diameter of 350 μm, a height of 250 μm, a hypotenuse angle of 65°, and a base diameter of 584 μm. Multiple substrate protrusions were formed such that the distance between the centers of the top surfaces in the X and Y directions of the substrate was 1.4 mm, resulting in 8750 substrate protrusions.

[0085] A dispersion of polyether ether ketone (PEEK) (product name: VICOTE F817, manufactured by Victrex) was prepared. Next, the substrate prepared above was fitted into a core, and while rotating at 200 rpm, the dispersion was applied using a spray gun (product name: W-101, manufactured by Anest Iwata Corporation) to form a coating film of the dispersion. Next, the substrate with the coating film was placed in a heating furnace and heated at 120°C for 5 minutes to dry the coating film, and then heated at 400°C for 15 minutes to bake the coating film, forming an adhesive layer, which is the first PEEK resin layer, with a thickness of 2 μm.

[0086] Next, a dispersion of polyether ether ketone (PEEK) (product name: VICOTE F804, manufactured by Victrex) and silicone resin particles with an average particle size of 2.0 μm (product name: Tospearl 120, manufactured by Momentive) were prepared. The PEEK and silicone resin were mixed in a ratio (mass ratio) of 97:3, and the mixture was applied to the first PEEK resin layer formed above using a spray gun (product name: W-101, manufactured by Anest Iwata Corporation) to form a coating film. Then, the substrate with the coating film was placed in a heating furnace and heated at 120°C for 5 minutes to dry the coating film, and then heated at 400°C for 15 minutes to bake the coating film, forming a second PEEK resin layer with a thickness of 10 μm. In this way, a friction-resistant layer containing PEEK and silicone resin was formed on the surface of the substrate on the side where the protrusions were formed. Furthermore, the thickness of the abrasion-resistant layer covering the upper surface of the protrusions on the base material was the same as the thickness of the abrasion-resistant layer covering the portion of the base material that does not have protrusions. In this way, the abrasion-resistant member according to Example A-2 was obtained. The obtained friction-resistant member was subjected to evaluations 1 and 2 described in Example A-1.

[0087] <Example A-3> Except for changing the mixing ratio (mass ratio) of PEEK and silicone resin in the abrasion layer of Example A-2 to 95:5 and forming the abrasion layer to a thickness of 30 μm, an abrasion member was prepared in the same manner as in Example A-2. The obtained abrasion member was subjected to evaluations 1 and 2 described in Example A-1.

[0088] <Example A-4> In Example A-2, the silicone resin in the abrasion layer was changed to silicone resin particles with an average particle size of 4.5 μm (product name: Tospar 145, manufactured by Momentive). The mixing ratio (mass ratio) of PEEK to silicone resin was set to 80:20, and the abrasion layer was formed to a thickness of 100 μm. The abrasion member was manufactured in the same manner as in Example A-2. The obtained abrasion member was subjected to evaluations 1 and 2 described in Example A-1.

[0089] <Example A-5> In Example A-2, the silicone resin in the abrasion layer was changed to silicone resin particles with an average particle size of 3.0 μm (product name: Tospar 130, manufactured by Momentive). The mixing ratio (mass ratio) of PEEK to silicone resin was set to 70:30, and the abrasion layer was formed to a thickness of 80 μm. The abrasion member was manufactured in the same manner as in Example A-2. The obtained abrasion member was subjected to evaluations 1 and 2 described in Example A-1.

[0090] <Comparative example A-1> In Example A-1, the abraded member was prepared in the same manner as in Example 1, except that the constituent material of the abraded layer was solely a dispersion of polyether ether ketone (PEEK) (product name: VICOTE F804, manufactured by Victrex). The obtained abraded member was subjected to evaluations 1 and 2 described in Example A-1.

[0091] <Comparative example A-2> In Example A-3, the abrasion-resistant layer was formed by extrusion molding. Specifically, molten polyether ether ketone (PEEK) resin (product name: 450G, manufactured by Victrex) was mixed with silicone resin particles (product name: Tospar 120, manufactured by Momentive) having an average particle size of 2.0 μm. This resulted in resin pellets mixed so that the PEEK to silicone resin ratio (mass ratio) was 90:10. The obtained resin pellets were then extruded to produce a sheet-like abrasion-resistant film with a thickness of 30 μm.

[0092] Next, an addition-curing silicone rubber adhesive (product name: SE1819CV, an equal mixture of "liquid A" and "liquid B" manufactured by Toray Dow Corning) was applied to the substrate formed in the same manner as in Example A-3 to a thickness of 2 μm. The sheet-like abrasion film prepared above was placed over the applied adhesive, and the adhesive was cured by heating in an electric furnace set to 200°C in a vacuum environment for 30 minutes to produce an abrasion member. The obtained abrasion member was subjected to evaluations 1 and 2 described in Example A-1.

[0093] Table 1 shows the configuration of the friction-bearing members for Examples A-1 to A-5 and Comparative Examples A-1 to A-2, and Table 2 shows the evaluation results.

[0094] [Table 1]

[0095] [Table 2]

[0096] As is clear from the results in Table 2, the presence of a resin with a polysiloxane structure on the surface protrusions significantly reduced the starting torque of the fixing device.

[0097] <Example B-1> An adhesive durability test was conducted using the abrasion-resistant member according to Example A-1. A full-color electrophotographic image forming apparatus was prepared with the abrasion-resistant member according to Example A-1 mounted on a pad, in the same manner as in Evaluation 2 of Example A-1. The adhesive durability test was performed in a mode in which the pressing rotating body 305 alternately contacts and does not contact the fixing rotating body 301, and the design target time for this mode in this evaluation was 240 hours.

[0098] First, 50 ml of lubricant was applied to the surface of the friction-resistant member to be evaluated, specifically the side where the surface protrusions were formed. The lubricant used was silicone oil (product name: KF-96-3000CS, manufactured by Shin-Etsu Chemical Co., Ltd.). The kinematic viscosity of this lubricant at a temperature of 25°C was 3000 mm². 2 It is / s.

[0099] Next, the abrasion member fixed to the outer surface of the pad of the fixing device of the full-color electrophotographic image forming apparatus was removed, and the abrasion member to be evaluated, which had been prepared above with a lubricant applied to its surface, was attached. The adhesive durability test described above was performed using this full-color electrophotographic image forming apparatus. The adhesive durability test was carried out for up to 720 hours, and the adhesion state between the substrate and the abrasion layer of the abrasion member was observed at 240 hours and 720 hours.

[0100] The adhesion state of the friction-affected components was evaluated according to the following criteria. (Evaluation criteria for the condition of friction-affected components) Rank A: No adhesive peeling after 720 hours of durability testing. Rank B: No adhesive peeling after 240 hours. Some adhesive peeling was observed after 720 hours of use (but does not affect functionality). Rank C: Adhesive delamination occurred after 240 hours.

[0101] <Examples B-2 to B-5 and Comparative Examples B-1 to B-2> Each of the friction-bearing members in Examples A-2 to A-5 and Comparative Examples A-1 to A-2 was subjected to the evaluation described in Example B-1, and was designated as Examples B-2 to B-5 and Comparative Examples B-1 to B-2, respectively. The results for Examples B-1 to B-5 and Comparative Examples B-1 to B-2 are shown in Table 3.

[0102] [Table 3]

[0103] As shown in Table 3, the evaluation of Examples B-1 and B-5, which used the abraded members from Examples A-1 and A-5, was rank B. The reason for this is that the area ratio B value in the observation area Y of the abraded members from Examples A-1 and A-5 was 3%, which is larger than the area ratio B value of the abraded members from Examples A-2 to A-4. Therefore, it is thought that there was a slightly larger amount of resin with a polysiloxane structure near the surface of the protrusions on the substrate, resulting in a slight deterioration in adhesion.

[0104] In comparative example B-2, adhesive delamination occurred after 240 hours. This is thought to be because the area ratio B in the observation area Y of the abraded member was large at 10%, and a large amount of resin with a polysiloxane structure was present near the surface of the protruding part of the substrate.

[0105] The embodiments relating to this disclosure include the following configurations. (Composition 1) A fixing device for fixing an unfixed toner image supported on a recording material to the recording material, The fixing device is Belt-shaped fixing rotating body, A pressing rotating body is positioned opposite the fixing rotating body and, together with the fixing rotating body, forms a nip portion. A friction member having a friction surface that is positioned inside the fixing rotating body and rubbed against the inner circumferential surface of the fixing rotating body via a lubricant, A pressing member is positioned inside the fixing rotating body and presses the fixing rotating body against the pressurizing rotating body via the friction-bearing member, and A heater for heating the fixing rotating body, It is equipped with, The lubricant is silicone oil, The abraded member is, Metal substrate and A layer that covers the surface of the metal substrate and has the surface to be scraped, It has, On the surface of the metal substrate on the side where the abrasion layer is present, there are multiple substrate protrusions. The surface to be rubbed has surface protrusions formed by the base material protrusions and the rubbed layer covering the base material protrusions. The abrasion layer comprises a thermoplastic resin and a resin having a polysiloxane structure. In a 25 μm × 25 μm observation area X on the surface of the surface protrusion, the area ratio A occupied by the resin having the polysiloxane structure is 5% or more and 50% or less. A fixing device characterized in that, in the cross-section in the thickness direction of the abraded layer, in the observation area Y of the abraded layer with a width of 5 μm from the surface of the abraded layer in contact with the protrusion of the substrate, the area ratio B occupied by the resin having a polysiloxane structure is 3% or less. (Configuration 2) The fixing device according to configuration 1, wherein the area ratio A is 10% or more and 50% or less. (Composition 3) The fixing device according to configuration 1 or 2, wherein the area ratio B is 1% or less. (Composition 4) A fixing device according to any one of configurations 1 to 3, wherein the average thickness of the abraded layer is 10 μm or more and 100 μm or less. (Composition 5) The fixing device according to any one of configurations 1 to 4, wherein the thermoplastic resin is polyether ether ketone. (Composition 6) The fixing device according to configuration 5, wherein the content of the polyetheretherketone in the abrasion layer is 70% by mass or more. (Composition 7) The fixing device according to any one of configurations 1 to 6, wherein the resin having the polysiloxane structure is a silicone resin. [Explanation of symbols]

[0106] 8. Fixing device 301 Rotating body for fixing 303 Pad (Backup component) 304 Abrasion-resistant member 304a base material 304b Rubbing layer 309 Lubricant 405 Substrate protrusion 407 Surface protrusions 501 Resins having a polysiloxane structure

Claims

1. A fixing device for fixing an unfixed toner image supported on a recording material to the recording material, The fixing device is Belt-shaped fixing rotating body, A pressing rotating body is positioned opposite the fixing rotating body and, together with the fixing rotating body, forms a nip portion. A friction member having a friction surface that is positioned inside the fixing rotating body and rubbed against the inner circumferential surface of the fixing rotating body via a lubricant, A pressing member is positioned inside the fixing rotating body and presses the fixing rotating body against the pressurizing rotating body via the friction-bearing member, and A heater for heating the fixing rotating body, It is equipped with, The lubricant is silicone oil, The abraded member is, Metal substrate and A layer that covers the surface of the metal substrate and has the surface to be scraped, It has, On the surface of the metal substrate on the side where the abrasion layer is present, there are multiple substrate protrusions. The surface to be rubbed has surface protrusions formed by the base material protrusions and the rubbed layer covering the base material protrusions. The abrasion layer comprises a thermoplastic resin and a resin having a polysiloxane structure. In an observation area X of 25 μm × 25 μm on the surface of the surface protrusion, the area ratio A occupied by the resin having the polysiloxane structure is 5% or more and 50% or less. A fixing device characterized in that, in a cross-section of the abraded layer in the thickness direction, in an observation area Y of the abraded layer with a width of 5 μm from the surface of the abraded layer in contact with the protrusions of the substrate, the area ratio B occupied by the resin having a polysiloxane structure is 3% or less.

2. The fixing device according to claim 1, wherein the area ratio A is 10% or more and 50% or less.

3. The fixing device according to claim 1 or 2, wherein the area ratio B is 1% or less.

4. The fixing device according to claim 1 or 2, wherein the average thickness of the abraded layer is 10 μm or more and 100 μm or less.

5. The fixing device according to claim 1 or 2, wherein the thermoplastic resin is polyetheretherketone.

6. The fixing device according to claim 5, wherein the content of the polyetheretherketone in the abrasion layer is 70% by mass or more.

7. The fixing device according to claim 1 or 2, wherein the resin having the polysiloxane structure is a silicone resin.

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