Rotating body for fixing, fixing device, electrophotographic image forming apparatus, and method for manufacturing rotating body for fixing, and conductive member

Abstract

To provide a rotating body for fixing that is excellent in durability even in a printing environment where a high temperature state continues long.SOLUTION: A rotating body for fixing is provided. The rotating body for fixing comprises a substrate including resin, and a heating layer on the substrate. The heating layer extends in a circumferential direction of an outer peripheral surface of the substrate. The heating layer includes silver. At least one hole is present in a cross section of the heating layer in a direction along the circumferential direction. When the heating layer is analyzed in a depth direction from a surface on the opposite side of a side facing the substrate, at a pitch of 375 nm, by using an X-ray photoelectron spectroscopic device, peaks of tellurium oxide are observed over the entire thickness of the heating layer.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a rotator for fixing used in a fixing device of an electrophotographic image forming apparatus such as an electrophotographic copying machine or a printer, a fixing device, an electrophotographic image forming apparatus, a method for manufacturing the rotator for fixing, and a conductive member.

Background Art

[0002] A fixing device mounted on an electrophotographic image forming apparatus such as an electrophotographic copying machine or a printer generally heats a recording material carrying an unfixed toner image in a nip portion formed by a rotator for fixing to be heated and a pressure roller contacting therewith to fix the toner image on the recording material while transporting the recording material.

[0003] A fixing device using an electromagnetic induction heating method in which a heat generating layer is provided on a rotator for fixing and the heat generating layer can be directly heated has been developed and put into practical use. The fixing device using the electromagnetic induction heating method has an advantage of a short warm-up time. The conductive layer is required to have conductivity and durability against repeated strain under heating. For example, Patent Document 1 discloses a fixing member having a conductive layer formed by copper plating.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The inventors of the present invention attempted to apply a nano ink capable of controlling a fine line width and space in forming a heat generating layer, expecting an effect of reducing heat generation unevenness. Pores exist in the heat generating layer formed of the nano ink. The presence of pores can be expected to improve the adhesion due to the anchor effect when forming a resin layer such as a protective layer.

[0006] On the other hand, in the fixing member, when sheets of different sizes are inserted, there is a phenomenon that the member temperature rises at the end where the sheet does not pass, that is, the so-called non-paper-passing part. Since the fixing member surely fixes the toner in the paper-passing part where the paper passes, it is heated so as to maintain the fixing temperature at any time. In the paper-passing part, since the paper passes while taking heat away, continuous heating is required. On the other hand, in the non-paper-passing part, since there is no heat transfer due to the passage of the paper, the member temperature may become higher than the set temperature. This phenomenon is likely to occur especially in a special use environment such as continuous printing of small-sized paper.

[0007] The inventors of the present invention confirmed the problem that when a fixing member using nanoink for manufacturing the heat generating layer is used, when a high temperature state above the set temperature continues for a long time in the non-paper-passing part, the resistance of the heat generating layer increases. When such an increase in resistance occurs in the non-paper-passing part of small-sized paper, unevenness occurs in the amount of heat generation by electromagnetic induction, and when fixing to a larger-sized paper, the fixability at the end of the paper decreases. The present disclosure is directed to a rotating body for fixing that has excellent durability even in a printing environment where a high temperature state continues for a long time. Further, the present disclosure is directed to a fixing device and an electrophotographic image forming device including the rotating body for fixing. Further, the present disclosure is directed to a method for manufacturing the rotating body for fixing. Further, the present disclosure is directed to a conductive member capable of suppressing an increase in resistance at high temperature.

Means for Solving the Problems

[0008] The present disclosure is a rotating body for fixing, The rotating body for fixing, a base material containing a resin, a heat generating layer on the base material, and the heat generating layer extends in the circumferential direction of the outer peripheral surface of the base material, the heat generating layer contains silver, in a cross section of the heat generating layer in a direction along the circumferential direction, at least one hole exists, Regarding a rotator for fixing, when analyzed with an X-ray photoelectron spectrometer at a pitch of 375 nm in the depth direction from the surface on the side opposite to the side facing the base material, a peak of tellurium oxide is confirmed over the entire thickness of the heat-generating layer.

[0009] In addition, the present disclosure relates to a fixing device including the above-described rotator for fixing and an induction heating device that generates heat in the rotator for fixing by induction heating.

[0010] In addition, the present disclosure relates to an electrophotographic image forming apparatus, wherein the electrophotographic image forming apparatus includes an image carrier that supports a toner image, a transfer device that transfers the toner image to a recording material, and a fixing device that fixes the transferred toner image to the recording material, and relates to an electrophotographic image forming apparatus, wherein the fixing device is the above-described fixing device.

[0011] In addition, the present disclosure relates to a method for manufacturing the above-described rotator for fixing, wherein the manufacturing method includes a step of preparing a laminate in which the heat-generating layer is formed on the base material, a step of impregnating a tellurium solution containing tellurium from the surface on the side opposite to the side facing the base material of the heat-generating layer, and a step of heating to 200°C or higher after impregnating the tellurium solution. The present disclosure relates to a method for manufacturing a rotator for fixing, including the above steps.

[0012] In addition, the present disclosure relates to a conductive member including a base material and a heat-generating layer on the base material, wherein the heat-generating layer contains silver, at least one void exists in a cross-section in the thickness direction of the heat-generating layer, and when analyzed with an X-ray photoelectron spectrometer at a pitch of 375 nm in the depth direction from the surface on the side opposite to the side facing the base material of the heat-generating layer, a peak of tellurium oxide is confirmed over the entire thickness of the heat-generating layer.

Advantages of the Invention

[0013] According to the present disclosure, a rotator for fixing, which has excellent durability even in a printing environment where a high temperature state continues for a long time, is provided. Further, according to the present disclosure, a fixing device and an electrophotographic image forming device including the rotator for fixing are provided. Further, according to the present disclosure, a method for manufacturing the rotator for fixing is provided. Further, according to the present disclosure, a conductive member capable of suppressing an increase in resistance at high temperature is provided.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0015] In the present disclosure, the description of "XX or more and YY or less" or "XX to YY" representing a numerical range means a numerical range including the lower limit and the upper limit which are endpoints, unless otherwise specified. When numerical ranges are described stepwise, the upper limit and the lower limit of each numerical range can be arbitrarily combined. Further, in the present disclosure, a description such as "at least one selected from the group consisting of XX, YY and ZZ" means any one 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.

[0016] A fixing rotating body having a heating layer according to the present disclosure, a fixing device including the fixing rotating body, and an image forming apparatus will be described in detail below based on specific configurations.

[0017] The present disclosure relates to a fixing rotating body, the fixing rotating body includes a base material containing resin, a heating layer on the base material, and is provided with the heating layer extends in the circumferential direction of the outer peripheral surface of the base material, the heating layer contains silver, in a cross-section of the heating layer in a direction along the circumferential direction, at least one void exists, relates to a fixing rotating body in which when the heating layer is analyzed by an X-ray photoelectron spectrometer at a pitch of 375 nm in the depth direction from the surface on the side opposite to the side facing the base material, a peak of tellurium oxide is confirmed over the entire thickness of the heating layer.

[0018] As described above, when a fixing member using nanoink for manufacturing the heating layer is used, if a high-temperature state above the set temperature continues for a long time in a non-paper-passing portion, the resistance of the heating layer may increase. Since a part of the voids formed by using nanoink is connected, it is considered that when the high-temperature state continues, oxidation progresses over the entire heating layer and the resistance increases.

[0019] The inventors of the present invention have found that by including tellurium oxide in the heating layer, an increase in the resistance of the heating layer can be suppressed even when a high-temperature state continues for a long time. Specifically, when the heating layer is analyzed by an X-ray photoelectron spectrometer at a pitch of 375 nm in the depth direction from the surface on the side opposite to the side facing the base material, it is necessary to confirm a peak of tellurium oxide over the entire thickness of the heating layer. Regarding the reason why the increase in the resistance of the heating layer can be suppressed by tellurium oxide, the inventors of the present invention think that tellurium oxide covers the inner surface formed by the voids of the heating layer to form a barrier layer, reducing the amount of contact between the heating layer itself and oxygen, and suppressing the increase in resistance even in a high-temperature state.

[0020] A fixing rotating body having a heat generating layer, a fixing device and an electrophotographic image forming apparatus using the same will be described in detail below based on specific configurations. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment should be appropriately changed according to the configurations of the members to which the disclosure is applied and various conditions. That is, it is not intended to limit the scope of this disclosure to the following embodiments. In the following description, components having the same function are given the same numbers in the drawings, and the description thereof may be omitted. There is.

[0021] (Electrophotographic Image Forming Apparatus) An electrophotographic image forming apparatus (hereinafter, also simply referred to as an "image forming apparatus") includes an image carrier that carries a toner image, a transfer device that transfers the toner image to a recording material, and a fixing device that fixes the transferred toner image to the recording material. FIG. 2 is a cross-sectional view showing the overall configuration of a color laser beam printer (hereinafter, referred to as a "printer") 1 as an example of an image forming apparatus equipped with a fixing device (image heating device) 15 according to an embodiment. A cassette 2 is retractably housed in the lower part of the printer 1. The cassette 2 stacks and houses a sheet P as a recording material. The sheet P in the cassette 2 is fed to a registration roller 4 in a state of being separated one by one by a separation roller 3. Note that as the sheet P as a recording material, various sheets with different sizes and materials can be used, such as paper such as plain paper and thick paper, plastic film, cloth, sheet materials with surface treatment such as coated paper, and special-shaped sheet materials such as envelopes and index paper.

[0022] The printer 1 includes an image forming unit 5 as an image forming means in which image forming stations 5Y, 5M, 5C, and 5K corresponding to the colors yellow, magenta, cyan, and black are arranged side by side in a horizontal row. The image forming station 5Y is provided with a photosensitive drum 6Y which is an image carrier (electrophotographic photoreceptor) that carries a toner image, and a charging roller 7Y as a charging means for uniformly charging the surface of the photosensitive drum 6Y.

[0023] Further, a scanner unit 8 is disposed below the image forming unit 5. The scanner unit 8 irradiates a laser beam that is input from an external device such as a computer (not shown) based on image information and is on / off modulated corresponding to a digital image signal generated by image processing means, to form an electrostatic latent image on the photosensitive drum 6Y. Further, the image forming station 5Y includes a developing roller 9Y as developing means for attaching toner to the electrostatic latent image on the photosensitive drum 6Y to develop it as a toner image (toner picture), and a primary transfer unit 11Y for transferring the toner image on the photosensitive drum 6Y to the intermediate transfer belt 10.

[0024] To the toner image on the intermediate transfer belt 10 onto which the toner image is transferred by the primary transfer unit 11Y, toner images formed by the same process in the other image forming stations 5M, 5C, 5K are multi-transferred. Thereby, a full-color toner image is formed on the intermediate transfer belt 10. This full-color toner image is transferred to the sheet P by a secondary transfer unit 12 as transfer means. The primary transfer unit 11Y and the secondary transfer unit 12 are examples of transfer devices for fixing the transferred toner image to a recording material. Thereafter, the toner image transferred onto the sheet P (on the recording material) passes through the fixing device 15 and is fixed as a fixed image. Further, the sheet P passes through the discharge conveyance unit 13 and is discharged and stacked on the stacking unit 14.

[0025] Note that the above image forming unit 5 is an example of image forming means, and for example, a configuration of a direct transfer method in which a toner image is directly transferred from an image carrier to the sheet P, or a configuration of a monochrome method using only one color of toner may be used.

[0026] (Fixing Device) The fixing device 15 of the present embodiment is an induction heating type fixing device (image heating device) that generates heat for the fixing rotating body by electromagnetic induction. FIG. 3 shows a cross-sectional configuration of the fixing device 15, and FIG. 4 is a perspective view of the fixing device 15. Note that the housing and the like of the fixing device 15 are omitted in FIGS. 3 and 4. In the following description, regarding the members constituting the fixing device 15, the longitudinal direction X1 is a direction orthogonal to the conveyance direction of the recording material and the thickness direction of the recording material.

[0027] The fixing device 15 includes a fixing rotating body 20, a film guide 25, a pressure roller 21, a pressure stay 22, a magnetic core 26, an exciting coil 27 (Fig. 5), a thermistor 40, and a current sensor 30. The fixing device 15 heats the recording material on which an image is formed and fixes the image on the recording material. The fixing rotating body 20 is the rotating body of the present embodiment, and the pressure roller 21 is the opposing member of the present embodiment. Further, the exciting coil 27 functions as the magnetic field generating means of the present embodiment. Details of the fixing rotating body will be described later.

[0028] The fixing rotating body 20 has a heat generating layer 20b on a base material. The heat generating layer 20b can generate heat by, for example, induced current. The heat generating layer 20b is formed in a ring shape with each being electrically connected in the circumferential direction, and heat generating rings 201 (Fig. 4) that are electrically divided in the longitudinal direction X1 (the rotation axis direction of the fixing rotating body 20) are formed as heat generating patterns arranged in the longitudinal direction. That is, the heat generating layer 20b is a plurality of annular regions each connected in the circumferential direction of the fixing rotating body 20, and is divided into a plurality of annular regions that are not electrically conductive with respect to the rotation axis direction of the fixing rotating body 20. Each heat generating ring 201, which is a component of the heat generating pattern, is formed with a uniform width in the longitudinal direction X1.

[0029] The pressure roller 21 as an opposing body (pressure member) facing the fixing rotating body 20 includes a mandrel 21a and an elastic layer 21b formed in a roller shape by integrally molding and coating concentrically around the mandrel, and a release layer 21c is provided on the surface layer. The elastic layer 21b is preferably made of a material with good heat resistance such as silicone rubber, fluororubber, or fluorosilicone rubber. Both ends of the mandrel 21a in the longitudinal direction are rotatably held and disposed between side chassis sheet metals (not shown) of the device via conductive bearings.

[0030] Also, as shown in Fig. 4, pressure springs 24a and 24b are respectively provided between both ends in the longitudinal direction of the pressure stay 22 and spring receiving members 23a and 23b on the device chassis side, so that a pressing force is applied to the pressure stay 22. Note that in the fixing device 15 of this embodiment, a pressing force of approximately 100 N to 300 N (approximately 10 kgf to approximately 30 kgf) is applied. As a result, the lower surface of the film guide 25 made of a heat-resistant resin such as PPS and the upper surface of the pressure roller 21 are pressed against each other with the fixing rotator 20, which is a cylindrical rotating body, interposed therebetween, forming a fixing nip portion N with a predetermined width. The film guide 25 functions as a nip portion forming member that forms a nip portion for sandwiching and conveying a recording material carrying a toner image via the fixing rotator 20 together with the pressure roller 21. Here, PPS is polyphenylene sulfide.

[0031] The pressure roller 21 is rotationally driven in the clockwise direction by a driving means (not shown), and a counterclockwise rotational force acts on the fixing rotator 20 due to the frictional force with the outer surface of the fixing rotator 20. As a result, the fixing rotator 20 rotates while sliding on the film guide 25.

[0032] FIG. 5 is a schematic diagram of the magnetic core 26 and the exciting coil 27 in FIG. 3, and the fixing rotator 20 is shown by a dashed line to explain the positional relationship with the fixing rotator 20. The induction heating device in a fixing device that heats the fixing rotator 20 by electromagnetic induction may include a magnetic core 26 and an exciting coil 27. The exciting coil 27 is disposed inside the fixing rotator 20. The exciting coil 27 has a helical shape portion whose helical axis is substantially parallel to the direction along the rotation axis of the fixing rotator 20, and forms an alternating magnetic field that causes the heating layer 20b to generate heat by electromagnetic induction. Substantially parallel means not only a state where the two axes are completely parallel, but also allowing a slight deviation to such an extent that the heating layer can generate heat by electromagnetic induction. The magnetic core 26 is disposed inside the helical shape portion, extends in the rotation axis direction of the fixing rotator 20, and does not form a loop outside the fixing rotator 20. The magnetic core 26 induces the magnetic force lines of the alternating magnetic field.

[0033] In FIG. 5, the magnetic core 26 is inserted into the hollow portion of the fixing rotator 20 which is a cylindrical rotating body. Further, the exciting coil 27 is spirally wound around the outer periphery of the magnetic core 26 and extends in the longitudinal direction of the fixing rotator 20. The magnetic core 26 has a cylindrical shape and is fixed by fixing means (not shown) so as to be positioned substantially at the center of the fixing rotator 20 in a cross section viewed in the longitudinal direction (see FIG. 3).

[0034] The magnetic core 26 provided inside the exciting coil 27 serves to guide the magnetic force lines (magnetic flux) of the alternating magnetic field generated by the exciting coil 27 to the inside of the heating layer 20b of the fixing rotator 20 and to form a path (magnetic circuit) for the magnetic force lines. The material of the magnetic core 26 is preferably at least one high-permeability soft magnetic material selected from the group consisting of materials with low hysteresis loss and high relative permeability, such as fired ferrite, ferrite resin, etc.

[0035] The cross-sectional shape of the magnetic core 26 only needs to be a shape that can be accommodated in the hollow portion of the fixing rotator 20, and although it does not need to be circular, a shape with a cross-sectional area that can be as large as possible is preferred. In this embodiment, the diameter of the magnetic core 26 is 10 mm and the length in the longitudinal direction is 280 mm.

[0036] The exciting coil 27 is formed by spirally winding a copper wire (single conductor) with a diameter of 1 to 2 mm coated with heat-resistant polyamide-imide around the magnetic core 26 for 20 turns. The exciting coil 27 is wound around the magnetic core 26 in a direction intersecting the rotation axis direction of the fixing rotator 20. Therefore, when a high-frequency alternating current is passed through this exciting coil 27, an alternating magnetic field is generated in a direction parallel to the rotation axis direction, and an induced current (circulating current) flows through each heating ring 201 of the heating layer 20b of the fixing rotator 20 to generate heat by the principle described later.

[0037] As shown in FIGS. 3 and 4, the thermistor 40 as the temperature detection means for detecting the temperature of the fixing rotator 20 is composed of a spring plate 40a and a thermistor element 40b. The spring plate 40a is a support member having spring elasticity that extends toward the inner surface of the fixing rotator 20. The thermistor element 40b as the temperature detection element is installed at the tip of the spring plate 40a. The surface of the thermistor element 40b is covered with a 50-μm-thick polyimide tape to ensure electrical insulation.

[0038] The thermistor 40 is fixedly installed at a position substantially at the center of the fixing rotator 20 in the longitudinal direction on the film guide 25. Then, the thermistor element 40b is pressed against the inner surface of the fixing rotator 20 by the spring elasticity of the spring plate 40a and held in a contact state. Note that the thermistor 40 may be arranged on the outer peripheral side of the fixing rotator 20.

[0039] The current sensor 30 that constitutes the conduction monitoring device for monitoring the circumferential conduction of the heating layer 20b is arranged at the same position as the thermistor 40 with respect to the longitudinal direction of the fixing device 15. That is, what the current sensor 30 monitors is the conduction state of the heating ring 201 at the position where the thermistor element 40b is in contact among the plurality of heating rings 201 that constitute the heat generation pattern of the fixing rotator 20.

[0040] (Heating principle) The heating principle of the fixing rotator 20 in the induction heating type fixing device 15 will be described. FIG. 6 is a conceptual diagram showing the moment when the current is increasing in the exciting coil 27 in the direction of arrow I0. The exciting coil 27 is inserted into the fixing rotator 20 and functions as a magnetic field generating means that forms an alternating magnetic field in the rotational axis direction of the fixing rotator 20 by flowing an alternating current, thereby generating an induced current I in the circumferential direction of the fixing rotator 20.

[0041] Also, the magnetic core 26 guides the magnetic force lines B (dotted lines in the figure) generated by the exciting coil 27 functions as a member that forms a magnetic circuit. In a general induction heating method, magnetic field lines penetrate through a heating layer to generate eddy currents, whereas in this embodiment, the magnetic field lines B form a loop outside the fixing rotating body. That is, the heating layer 20b mainly generates heat due to the induced current induced by the magnetic field lines that emerge from one longitudinal end of the magnetic core 26, pass outside the heating layer 20b, and return to the other longitudinal end of the magnetic core 26. By doing so, even if the thickness of the heating layer is as thin as 5 μm or less, heat can be efficiently generated.

[0042] When an alternating magnetic field is formed by the exciting coil 27, an induced current I that follows Faraday's law flows through each heating ring 201 of the heating layer 20b of the fixing rotating body 20. Faraday's law states that "when the magnetic field in a circuit is changed, an induced electromotive force that attempts to flow a current is generated in the circuit, and the induced electromotive force is proportional to the time change of the magnetic flux that perpendicularly penetrates the circuit."

[0043] Regarding the heating ring 201c located at the central part in the longitudinal direction of the magnetic core 26 shown in FIG. 6, consider the induced current I flowing through the heating ring 201c when a high-frequency alternating current is passed through the exciting coil 27. When a high-frequency alternating current is passed, an alternating magnetic field is formed inside the magnetic core 26. The induced electromotive force acting on the heating ring 201c at that time is proportional to the time change of the magnetic flux that perpendicularly penetrates the inside of the heating ring 201c according to the following mathematical formula 1.

[0044]

Equation

[0045] Due to this induced electromotive force V, an induced current I, which is a circulating current that circulates through the heating ring 201c, flows, and the heating ring 201c generates heat due to the Joule heat generated along with the induced current I. However, when the heating ring 201c is disconnected, the induced current I does not flow, and the heating ring 201c does not generate heat.

[0046] (1) Schematic Configuration of the Rotating Member for Fixing The details of the rotating member for fixing according to the present embodiment will be described with reference to the drawings. The rotating member for fixing according to one aspect of the present disclosure can be a rotatable member such as an endless belt shape, for example. The rotating member for fixing includes a base material containing a resin and a heating layer on the base material. The rotating member for fixing may include a protective layer on the surface opposite to the side of the heating layer facing the base material, if necessary.

[0047] FIG. 7 is a cross-sectional view in the circumferential direction of the rotating member for fixing. As shown in FIG. 7, the rotating member for fixing has a base material 20a, a heating layer 20b on the outer surface of the base material 20a, and a protective layer 20e on the outer surface of the heating layer, if necessary. It is also possible to have an elastic layer 20c and a surface layer (release layer) 20d on the protective layer 20e, if necessary, and it is also possible to have an adhesive layer 20f between the elastic layer 20c and the surface layer 20d.

[0048] (2) Base Material The material of the base material 20a is not particularly limited. The base material 20a contains a resin (preferably a heat-resistant resin). When using the belt in a fixing device of the electromagnetic induction method, the base material 20a is a layer that has little change in physical properties in a state where the heating layer generates heat and maintains high strength. For this reason, the base material 20a preferably contains a heat-resistant resin as a main component, and more preferably is composed of a heat-resistant resin.

[0049] The resin contained in the base material 20a (preferably the resin constituting the base material) preferably contains at least one selected from the group consisting of polyimide (PI), polyamideimide (PAI), modified polyimide, and modified polyamideimide. More preferably, it is at least one selected from the group consisting of polyimide and polyamideimide. Among these, polyimide is particularly preferable. In the present disclosure, the main component means the component that is contained the most among the components constituting the object (here, the base material). Note that the modification in modified polyimide and modified polyamideimide includes siloxane modification, carbonate modification, fluorine modification, urethane modification, triazine modification, phenol modification, and the like.

[0050] A filler may be blended in the base material 20a to improve heat insulation and strength. The shape of the base can be appropriately selected according to the shape of the fixing rotating body, and can be various shapes such as an endless belt shape, a hollow cylindrical shape, a film shape, etc.

[0051] In the case of a fixing belt, the thickness of the base material 20a is preferably, for example, 10 to 100 μm, and more preferably 20 to 60 μm. By setting the thickness of the base material 20a within the above range, high levels of both strength and flexibility can be achieved simultaneously. Also, on the surface of the base material 20a on the side opposite to the side facing the heat generating layer 20b, for example, a layer for preventing wear of the inner peripheral surface of the fixing belt when the inner peripheral surface of the fixing belt contacts other members, or a layer for improving slidability with other members can be provided.

[0052] Other members such as sliding members are arranged on the inner surface of the base material 20a, and the sliding load is large. Therefore, in order to ensure the durability as a base material, the base material is preferably a solid layer. Note that the outer peripheral surface of the base material 20a may be subjected to roughening treatment such as blasting or modification treatment such as ultraviolet rays, plasma, or chemical etching to improve adhesion and wettability with the heat generating layer 20b.

[0053] (3) Heating layer The heating layer 20b is a layer that generates heat when energized. In the principle of heat generation by induction heating using an exciting coil, when an alternating current is supplied to the exciting coil disposed near the fixing rotating body, a magnetic field is induced, and a current is generated in the heating layer 20b of the fixing rotating body by this magnetic field, and heat is generated due to Joule heat. The heating layer extends in the circumferential direction on the outer peripheral surface of the base material.

[0054] The heating layer contains silver. Silver has a low volume resistivity and is difficult to oxidize. As the content of silver in the entire heating layer 20b, 90.0% by mass or more is preferable, 99.0% by mass or more is more preferable, and 99.9% by mass or more is particularly preferable. The upper limit is, for example, 99.999% by mass or less, 99.99% by mass or less.

[0055] The volume resistivity of the heating layer 20b is preferably 1.0×10 -8 ~8.0×10 -8 Ω·m, 2.0×10 -8 ~7.0×10 -8 Ω·m, 2.0×10 -8 ~6.0×10 -8 Ω·m.

[0056] The thickness of the heating layer 20b is preferably 5 μm or less. This is because it is desired to give the fixing rotating body appropriate flexibility and reduce the heat capacity. Another merit is the improvement of the bending resistance performance. As shown in FIG. 3, the fixing rotating body 20 is rotationally driven while being pressed by the film guide 25 and the pressure roller 21. Each time it makes one rotation, the fixing rotating body 20 is pressurized and deformed in the nip portion N and receives stress. It will be pressurized and deformed in the nip portion N and receive stress.

[0057] Even if this repeated bending is continuously applied until the durability life of the fixing device, it is preferable to design the heating layer 20b of the fixing rotating body 20 so as not to cause fatigue failure. When the thickness of the heating layer 20b is reduced, the resistance of the heating layer 20b to fatigue failure is significantly improved. This is because when the heating layer 20b is pressed and deformed along the curved surface shape of the film guide 25, the internal stress acting on the heating layer 20b becomes smaller as the heating layer 20b is thinner. For the above reasons, from the viewpoint of further improving the reduction of heat capacity and the resistance to fatigue failure, the thickness of the heating layer 20b is preferably 5 μm or less. Examples of the thickness of the heating layer 20b include 1 to 5 μm, 2 to 5 μm, and 2 to 4 μm.

[0058] The heating layer 20b extends in the circumferential direction on the outer peripheral surface of the base material 20a. The heating layer 20b only needs to be capable of generating heat when energized and may be configured in a predetermined pattern. In particular, as shown in FIG. 4, a configuration in which a plurality of heating layers 20b formed in a ring shape in the circumferential direction of the fixing rotating body are electrically divided in the rotation axis direction is preferable from the viewpoint of safety. By adopting such a configuration, a local temperature rise when a crack occurs in the heating layer 20b can be suppressed. The ring shape preferably has a substantially constant width in the rotation axis direction. However, when such a pattern configuration is adopted, the surface area of the heating layer 20b increases and the risk of deterioration due to oxidation increases, so silver is used.

[0059] From the viewpoints of manufacturability and heat generation performance, the width of the ring of the heating layer 20b is preferably 100 μm or more, more preferably 200 μm or more, and even more preferably 300 μm or more. From the viewpoints of heat generation unevenness and safety, it is preferably 1000 μm or less, more preferably 900 μm or less, and even more preferably 700 μm or less. Examples of the ring width include 100 to 1000 μm, 200 to 900 μm, and 300 to 700 μm.

[0060] The interval between the rings in the heating layer 20b is preferably 50 μm or more, more preferably 100 μm or more, from the viewpoints of manufacturability and heat generation performance. From the viewpoint of heat generation unevenness, it is preferably 400 μm or less, more preferably 300 μm or less. Examples of the interval between the rings include 50 to 400 μm and 100 to 300 μm.

[0061] The heating layer has pores. Specifically, at least one pore exists in the cross-section along the circumferential direction of the heating layer. The presence of pores in the heating layer has the effect of improving durability due to the anchor effect when forming the protective layer. From the viewpoints of conductivity and durability of conductivity, it is preferable to adjust the amount and size of the pores.

[0062] Examples of the method for forming pores in the heating layer 20b include forming a pattern by a photolithography process on the heating layer 20b and then making holes by chemical solution etching, or making holes using a laser or a focused ion beam. In the present disclosure, in particular, the formation of pores using a silver nanoparticle material will be described.

[0063] The heating layer is preferably a fired body of a coating film of silver nanoink. When a coating material containing silver nanoparticles having a particle size of about 10 to 50 nm is formed into a film, the particles are stacked as shown in FIG. 8A. Due to the instability of the surface energy of the nanoparticles, the particles can fuse with each other even at a low firing temperature of about 100 ° C. and form a film with nano-sized pores as shown in FIG. 8B. The size and number of the pores can be expressed as a porosity.

[0064] Specifically, the ratio (porosity) of the pores in the cross-section of the heating layer, which is measured by observing the cross-section obtained by cutting the heating layer sampled from the fixing rotator in the thickness direction, is preferably 15 to 50 area%, more preferably 15 to 45 area%, and even more preferably 17 to 40 area%. is even more preferable. The porosity can be increased by increasing the temperature during firing of the heating layer. Also, the porosity can be decreased by decreasing the temperature during firing of the heating layer.

[0065] Here, the porosity in the heat generating layer is determined as follows. First, a sample for evaluation is prepared. From the fixing rotating body, a sample with a length of 5 mm, a width of 5 mm, and a thickness equal to the total thickness of the fixing rotating body is collected at an arbitrary location on the fixing rotating body. For the obtained sample, the circumferential cross-section of the fixing rotating body is polished using an ion beam. At this time, the processing position is adjusted so that the circumferential cross-section of the heat generating layer is exposed by the polishing process of the ion beam.

[0066] For the polishing process of the cross-section by the ion beam, an ion milling device (product name: IM4000, manufactured by Hitachi High-Technologies Corporation) can be used. In the polishing process of the cross-section by the ion beam, it is possible to prevent the filler from falling off the sample and the abrasive from being mixed in, and it is also possible to form a cross-section with few polishing marks. Subsequently, the cross-section of the heat generating layer is observed with a scanning electron microscope (SEM) (product name: JSM-F100, manufactured by JEOL Ltd.), and a cross-sectional image is obtained. The observation conditions are in the reflected electron image mode at 20,000 times magnification, and the conditions for obtaining the reflected electron image are an acceleration voltage of 3.0 kV and a working distance of 3 mm.

[0067] Next, the obtained image is cut out in a range of 0.5 μm × 0.5 μm in size at an arbitrary location using commercially available image software. Then, a binarization process is performed so that the crystal particle portion of the metal containing silver in the cut-out image is white and the portion other than the crystal particles is black. As a binarization method, for example, the Otsu method can be used.

[0068] Specifically, first, the reflected electron image is read using the image analysis software ImageProPlus manufactured by MediaCybernetics, the image is cut out in an arbitrary range of 0.5 μm × 0.5 μm, and the luminance distribution of this image is obtained. Next, by setting the luminance range of the obtained luminance distribution, binarization can be performed to distinguish the crystal particle portion of the metal containing silver and the portion other than the crystal particles.

[0069] A method for calculating the porosity from the binary image of the cross-section of the heat-generating layer obtained in this way will be described. Since digital image processing technology is applied to these images, it is assumed that all the images are in a general digital image format with pixels arranged in a grid pattern. Also, the binary image is a grayscale image with only luminance information, and all the images obtained by performing image processing on these images later are grayscale images in the same format unless otherwise specified.

[0070] In the binary image obtained in the above procedure, each particle of the metal crystal containing silver is represented as a white region, and the area occupied by each crystal particle in the image is calculated. Specifically, the number of pixels constituting each crystal particle is calculated, and the sum of the number of pixels is calculated. By multiplying the sum of the number of pixels by the area of one pixel, 0.15 × 0.15 μm 2 the area occupied by the crystal particles can be calculated.

[0071] Since the porosity indicates the ratio of the space not occupied by the crystal particles, using the area occupied by the crystal particles obtained above, Porosity = (0.5 × 0.5 (μm 2 ) - Area occupied by crystal particles (μm 2 )) ÷ 0.5 × 0.5 (μm 2 ) × 100 can be expressed as. The above calculation of the porosity is performed for 20 arbitrary ranges of 0.5 μm × 0.5 μm in the size of the cross-sectional image of the heat-generating layer, and the average porosity obtained by arithmetic averaging is taken as the porosity of the heat-generating layer.

[0072] As described above, when analyzed by an X-ray photoelectron spectrometer, a tellurium oxide peak is confirmed over the entire thickness of the heat-generating layer. In each analysis every 375 nm by the X-ray photoelectron spectrometer, the ratio (atomic %) of the elemental intensity of Te to the elemental intensities of C, N, O, Si, Cl, Ag, Te is preferably 0.1 to 20.00 atomic %, more preferably 0.10 to 10.00 atomic %.

[0073] In this way, the heating layer containing tellurium oxide can be formed, for example, by impregnating a solution containing tellurium into the heating layer. As the coating method, it is possible to use dip coating, spray coating, flow coating, contact coating with a sponge, etc. In the present disclosure, the coating method using a sponge will be described.

[0074] Prepare a hydrochloric acid solution in which tellurium is dissolved as a tellurium solution, and impregnate the tellurium solution into the heating layer. For example, impregnate the tellurium solution into a urethane sponge and trace the surface of the heating layer. The concentration of tellurium in the tellurium solution is, for example, 0.01 to 0.30% by mass. Also, the concentration of hydrochloric acid is, for example, 0.1 to 3.0% by mass. After tracing evenly, it is preferably washed away with purified water and the remaining moisture is removed by N2 blowing. Then, it is dried by placing it on a preheated hot plate and holding it at, for example, 120 to 180°C for 5 to 60 minutes. Since there are pores, the moisture that cannot be completely removed by N2 blowing can be removed by drying.

[0075] After that, heat the heating layer. The heating temperature is 200°C or higher, preferably 200 to 300°C, more preferably 220 to 260°C. The heating time is preferably 1 to 100 hours, and examples include 10 to 60 hours. For example, the laminate including the heating layer is put into an oven in an air atmosphere and maintained in a state of being heat-treated at 240°C for 48 hours. By passing through these steps, a part of tellurium sublimes and redeposits as tellurium oxide, so that tellurium oxide can be formed throughout the heating layer. Since the porosity of the heating layer is within the above-described range, it is easy to form tellurium oxide throughout the heating layer.

[0076] That is, the manufacturing method of the fixing rotating body preferably includes a step of preparing a laminate in which a heating layer is formed on a substrate, a step of impregnating a tellurium solution containing tellurium from the surface on the side opposite to the side facing the substrate of the heating layer, and a step of heating to 200°C or higher after impregnating the tellurium solution.

[0077] ​Note that the step of preparing the laminate is, for example, a step of obtaining a base material, a step of obtaining a heat-generating layer by applying silver nanoparticle ink to the outer peripheral surface of the obtained base material and firing it and has. The step of obtaining the base material is not particularly limited. For example, it can be a base material having an endless belt shape or a roller shape. For example, a base material can be obtained by applying a resin material of the base material to the surface of a mold such as a cylindrical shape and heating it as necessary. Next, silver nanoparticle ink is applied to the outer peripheral surface of the obtained base material and fired (sintered) to form a heat-generating layer. The temperature during firing is not particularly limited, but is preferably 150 to 450 ° C, more preferably 250 to 350 ° C. That is, the heat-generating layer is preferably a fired body (sintered body) of silver nanoparticles. The firing time is also not particularly limited, and examples thereof include 10 to 120 minutes.

[0078] (4) Resin layer In the present disclosure, the portion including the protective layer 20e, the elastic layer 20c, the adhesive layer 20f, and the surface layer 20d may be expressed as a resin layer. The resin layer may be only one protective layer or only one surface layer.

[0079] (5) Protective layer The fixing rotator may include a protective layer on the surface opposite to the side facing the base material of the heat-generating layer. The protective layer 20e protects the heat-generating layer 20b and has functions of preventing oxidation of the heat-generating layer 20b, ensuring insulation, and improving strength.

[0080] The material constituting the protective layer 20e is not particularly limited. The material of the protective layer 20e is preferably a layer containing at least resin. When the belt is used in an electromagnetic induction type fixing device, similar to the base material 20a, the protective layer 20e is preferably a layer having little change in physical properties and maintaining high strength in a state where the heat-generating layer 20b generates heat. Therefore, the protective layer 20e preferably contains a heat-resistant resin, more preferably contains a heat-resistant resin as a main component, and preferably consists of a heat-resistant resin. The heat-resistant resin is, for example, a resin that does not melt or decompose at a temperature of less than 200 °C (preferably less than 250 °C).

[0081] The resin constituting the protective layer 20e preferably contains at least one selected from the group consisting of polyimide (PI), polyamideimide (PAI), modified polyimide, and modified polyamideimide. More preferably, it is at least one selected from the group consisting of polyimide and polyamideimide. The modification is the same as that described for the base material 20a. Among these, polyimide is particularly preferred. The main component means the component that is contained the most among the components constituting the object (here, the protective layer). The formation method of the base material 20a and the protective layer 20e is not particularly limited. For example, an imide-based material can be formed into a film by coating and baking it in a liquid state called a varnish using a known method.

[0082] The protective layer 20e may contain a heat-conductive filler from the viewpoint of heat conductivity. By improving the heat conductivity, the heat generated in the heat-generating layer 20b can be efficiently transmitted to the outer surface of the fixing rotator.

[0083] The thickness of the protective layer 20e is preferably 10 to 100 μm, more preferably 20 to 60 μm. From the viewpoint of the bending resistance of the heat-generating layer 20b, the thickness of the protective layer 20e is preferably the same as the thickness of the base material 20a. For example, the ratio of the difference in thickness between the base material and the protective layer to the thickness of the base material is preferably 20% or less, 10% or less, 5% or less. This is because by reducing the difference in thickness, when the heat-generating layer 20b is repeatedly bent at the nip portion, the stress applied to the heat-generating layer 20b is in a state without bias, and the generation of cracks in the heat-generating layer 20b can be suppressed.

[0084] (6) Elastic layer The fixing rotating body may have an elastic layer 20c on the outer surface of the protective layer 20e. The elastic layer 20c is a layer for imparting flexibility to the fixing rotating body in order to secure a fixing nip in the fixing device. When the fixing rotating body is used as a heating member that contacts the toner on the paper, the elastic layer 20c also functions as a layer for imparting flexibility such that the surface of the heating member can follow the unevenness of the paper. The elastic layer 20c includes, for example, rubber as a matrix and particles dispersed in the rubber. More specifically, the elastic layer 20c preferably includes rubber and a heat conductive filler, and is preferably composed of a cured product obtained by curing a composition containing at least a raw material of rubber (base polymer, crosslinking agent, etc.) and a heat conductive filler.

[0085] From the viewpoint of expressing the functions of the elastic layer 20c described above, the elastic layer 20c is preferably composed of a cured product of a silicone rubber containing heat conductive particles, and more preferably composed of a cured product of an addition-curing type silicone rubber composition. The silicone rubber composition can include, for example, heat conductive particles, a base polymer, a crosslinking agent, a catalyst, and, if necessary, additives. Since the silicone rubber composition is often in a liquid state, the heat conductive filler is easily dispersed, and it is easy to adjust the elasticity of the elastic layer 20c to be produced by adjusting the degree of crosslinking according to the type and addition amount of the heat conductive filler.

[0086] The matrix undertakes the function of expressing elasticity in the elastic layer 20c. From the viewpoint of expressing the functions of the elastic layer 20c described above, the matrix preferably includes silicone rubber. Silicone rubber has high heat resistance that can maintain flexibility even in an environment where the temperature reaches about 240°C in the non-paper-passing area, which is preferable. As the silicone rubber, for example, a cured product of an addition-curing type liquid silicone rubber composition described later can be used. The elastic layer 20c can be formed by applying and heating a liquid silicone rubber composition by a known method.

[0087] The liquid silicone rubber composition usually includes the following components (a) to (d): Component (a): an organopolysiloxane having an unsaturated aliphatic group; Component (b): an organopolysiloxane having active hydrogen bonded to silicon; Component (c): a catalyst; Component (d): a thermal conductivity filler The following is an explanation of each component.

[0088] Component (a) The organopolysiloxane having an unsaturated aliphatic group is an organopolysiloxane having an unsaturated aliphatic group such as a vinyl group, and examples thereof include those represented by the following formulas (1) and (2).

Chemical formula

[0089] In formula (1), m 1 represents an integer of 0 or more, and n 1 represents an integer of 3 or more. Further, in structural formula (1), R 1 each independently represents a monovalent unsubstituted or substituted hydrocarbon group not containing an unsaturated aliphatic group, provided that at least one of R 1 represents a methyl group, and R 2 each independently represents an unsaturated aliphatic group.

Chemical formula

[0090] In formula (2), n 2 represents a positive integer, and R 3 each independently represents a monovalent unsubstituted or substituted hydrocarbon group not containing an unsaturated aliphatic group, provided that at least one of R 3 represents a methyl group, and R 4 each independently represents an unsaturated aliphatic group.

[0091] In formulas (1) and (2), R 1 and R 3Examples of the monovalent unsubstituted or substituted hydrocarbon group containing no unsaturated aliphatic group that can be represented include the following groups. are as follows. · Unsubstituted hydrocarbon group Alkyl group (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group). Aryl group (e.g., phenyl group). · Substituted hydrocarbon group Substituted alkyl group (e.g., chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group, 3-cyanopropyl group, 3-methoxypropyl group).

[0092] The organopolysiloxanes represented by formulas (1) and (2) have at least one methyl group directly bonded to the silicon atom forming the chain structure. However, since they are easy to synthesize and handle, it is preferable that more than 50% of each of R 1 and R 3 is a methyl group, and it is more preferable that all of R 1 and R 3 are methyl groups.

[0093] In addition, examples of the unsaturated aliphatic group that R 2 and R 4 in formulas (1) and (2) can represent include the following groups. That is, examples of the unsaturated aliphatic group include vinyl group, allyl group, 3-butenyl group, 4-pentenyl group, 5-hexenyl group, etc. Among these groups, since they are easy to synthesize and handle, inexpensive, and the crosslinking reaction can be easily carried out, it is preferable that both R 2 and R 4 are vinyl groups.

[0094] From the viewpoint of moldability, the viscosity of component (a) is preferably 1000 mm 2 / s or more and 50000 mm 2 / s or less. If it is lower than 1000 mm 2 / s, it becomes difficult to adjust to the hardness required for the elastic layer 20c, and if it is higher than 50000 mm 2If it is higher than / s, the viscosity of the composition becomes too high, making it difficult to apply. The viscosity (kinematic viscosity) can be measured using a capillary viscometer, a rotational viscometer, etc. based on JIS Z 8803:2011.

[0095] The blending amount of component (a) is preferably 55% by volume or more from the viewpoint of durability and 65% by volume or less from the viewpoint of heat conductivity, based on the liquid silicone rubber composition used for forming the elastic layer 20c.

[0096] Component (b) The organopolysiloxane having active hydrogen bonded to silicon reacts with the unsaturated aliphatic group of component (a) by the action of a catalyst and functions as a crosslinking agent for forming a cured silicone rubber.

[0097] As component (b), any organopolysiloxane having an Si-H bond can be used. In particular, from the viewpoint of reactivity with the unsaturated aliphatic group of component (a), those having an average of 3 or more hydrogen atoms bonded to silicon atoms in one molecule are preferably used.

[0098] Specific examples of component (b) include, for example, the linear organopolysiloxane represented by the following formula (3) and the cyclic organopolysiloxane represented by the following formula (4).

Chemical formula

[0099] In formula (3), m 2 represents an integer of 0 or more, n 3 represents an integer of 3 or more, and R 5 each independently represents a monovalent unsubstituted or substituted hydrocarbon group not containing an unsaturated aliphatic group.

Chemical formula

[0100] In formula (4), m 3 represents an integer of 0 or more, n 4represents an integer of 3 or more, and R 6 each independently represents a monovalent unsubstituted or substituted hydrocarbon group that does not contain an unsaturated aliphatic group.

[0101] R in formulas (3) and (4) 5 and R 6 Examples of the monovalent unsubstituted or substituted hydrocarbon group that does not contain an unsaturated aliphatic group that can be represented include groups similar to R in structural formula (1) described above. 1 Among these, since they are easy to synthesize and handle, and excellent heat resistance can be easily obtained, it is preferable that 50% or more of each of R 5 and R 6 is a methyl group, and it is more preferable that all of R 5 and R 6 are methyl groups.

[0102] Component (c) Examples of the catalyst used for forming the silicone rubber include, for example, a hydrosilylation catalyst for promoting the curing reaction. As the hydrosilylation catalyst, for example, known substances such as platinum compounds and rhodium compounds can be used. The blending amount of the catalyst can be set appropriately and is not particularly limited.

[0103] Component (d) Examples of the heat conductive filler include metals, metal compounds, and carbon fibers. A high heat conductive filler is more preferable, and specific examples thereof include the following materials. Metal silicon (Si), silicon carbide (SiC), silicon nitride (Si3N4), boron nitride (BN), aluminum nitride (AlN), alumina (Al2O3), zinc oxide (ZnO), magnesium oxide (MgO), silica (SiO2), copper (Cu), aluminum (Al), silver (Ag), iron (Fe), nickel (Ni), vapor grown carbon fiber, PAN-based (polyacrylonitrile) carbon fiber, pitch-based carbon fiber.

[0104] These fillers can be used alone or in combination of two or more. The average particle size of the filler is preferably 1 μm or more and 50 μm or less from the viewpoints of handling and dispersibility. Further, as the shape of the filler, spherical, pulverized, needle-like, plate-like, whisker-like shapes are used. In particular, from the viewpoint of dispersibility, the filler is preferably spherical. Furthermore, at least one of a reinforcing filler, a heat-resistant filler, and a coloring filler may be added.

[0105] (7) Adhesive layer The fixing rotator may have an adhesive layer 20f for adhering a surface layer 20d described later to the outer surface of the elastic layer 20c. The adhesive layer 20f is a layer for adhering the elastic layer 20c and the surface layer 20d. The adhesive used for the adhesive layer 20f can be appropriately selected from known ones and is not particularly limited. However, from the viewpoint of ease of handling, it is preferable to use an addition-curing type silicone rubber containing a self-adhesive component. This adhesive can contain, for example, a self-adhesive component, an organopolysiloxane having a plurality of unsaturated aliphatic groups represented by a vinyl group in the molecular chain, a hydrogen organopolysiloxane, and a platinum compound as a crosslinking catalyst. Applied to the surface of the elastic layer 20c By curing the adhesive by an addition reaction, an adhesive layer 20f for adhering the surface layer 20d to the elastic layer 20c can be formed.

[0106] Note that examples of the above self-adhesive component can include the following. · A silane having at least one, preferably two or more functional groups selected from the group consisting of an alkenyl group such as a vinyl group, a (meth)acryloxy group, a hydrosilyl group (SiH group), an epoxy group, an alkoxysilyl group, a carbonyl group, and a phenyl group. · An organosilicon compound such as a cyclic or linear siloxane having 2 to 30, preferably 4 to 20 silicon atoms. · A non-silicon-based (i.e., not containing a silicon atom in the molecule) organic compound that may contain an oxygen atom in the molecule. However, it contains 1 to 4, preferably 1 to 2, aromatic rings such as a phenylene structure having a valence of 1 or more and 4 or less, preferably 2 or more and 4 or less, in one molecule. And it contains at least 1, preferably 2 to 4, functional groups (e.g., alkenyl group, (meth)acryloxy group) that can contribute to the hydrosilylation addition reaction in one molecule.

[0107] The above self-adhesive component may be used alone or in combination of two or more. Further, in the adhesive, from the viewpoints of viscosity adjustment and heat resistance ensuring, a filler component can be added within the range in line with the gist of the present invention. Examples of the filler component include the following. · Silica, alumina, iron oxide, cerium oxide, cerium hydroxide, carbon black, etc.

[0108] The blending amount of each component contained in the adhesive is not particularly limited and can be set as appropriate. Such an addition-curing type silicone rubber adhesive is also commercially available and can be easily obtained. The thickness of the adhesive layer 20f is preferably 20 μm or less. By setting the thickness of the adhesive layer 20f to 20 μm or less, when the fixing belt according to this aspect is used as a heating belt in a heat fixing device, the thermal resistance can be easily set small, and the heat from the inner surface side can be efficiently transmitted to the recording medium.

[0109] (8) Surface layer The fixing rotator may have a surface layer 20d. The surface layer 20d preferably contains a fluororesin in order to exhibit the function as a release layer for preventing the adhesion of toner to the outer surface of the fixing rotator. For the formation of the surface layer 20d, for example, a resin formed into a tubular shape as exemplified below may be used, or a resin dispersion may be coated to form the surface layer 20d. · Tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), etc. Among the resin materials exemplified above, PFA is particularly preferably used from the viewpoints of moldability and toner releasability.

[0110] The thickness of the surface layer 20d is preferably 10 μm or more and 50 μm or less. By setting the thickness of the surface layer 20d within this range, it is easy to maintain an appropriate surface hardness of the fixing rotator.

[0111] As described above, according to one aspect of the present disclosure, a fixing device in which a fixing rotator is arranged is provided. Therefore, it is possible to provide a fixing device in which a fixing rotator having high conductivity and excellent durability is arranged. Further, the present disclosure provides a conductive member having a base material and a heat generating layer on the base material. The base material and the heat generating layer are as described above. Such a conductive member can suppress an increase in resistance at high temperatures.

Example

[0112] Hereinafter, the present disclosure will be described in more detail using examples, but the present invention is not limited to these examples.

[0113] [Example 1] A release treatment was performed on the surface of a cylindrical stainless steel mold having an outer diameter of 30 mm, and a coating film was formed by applying a commercially available polyimide precursor solution (U varnish S, manufactured by Ube Industries, Ltd.) by an immersion method. Next, this coating film was dried at 140° C. for 30 minutes to volatilize the solvent in the coating film, and then fired at 200° C. for 30 minutes and 400° C. for 30 minutes for imidization to form a polyimide film base material having a film thickness of 40 μm and a length of 300 mm. Next, a ring pattern was formed on this polyimide film by an inkjet method using silver nanoparticle-containing ink (DNS169I, manufactured by Daicel Corporation) so as to have a width of 300 μm and an interval of 200 μm. Then, firing was performed at 300° C. for 30 minutes to form a heat generating layer 20b having a film thickness of 3 μm.

[0114] Next, tellurium oxide was formed over the entire heat generating layer by the following method. A hydrochloric acid solution in which tellurium was dissolved (tellurium concentration: 0.20% by mass, hydrochloric acid concentration: 2.0% by mass) was prepared, impregnated into a urethane sponge, and used to trace the surface of the heat-generating layer. After tracing evenly, it was rinsed with purified water, and the remaining moisture was removed by N2 blowing. Then, it was placed on a pre-heated hot plate and maintained at 150 °C for 10 minutes. Further, it was put into an oven in an air atmosphere and heat-treated at 240 °C for 48 h. By passing through these steps, tellurium oxide was formed throughout the heat-generating layer.

[0115] Next, a PAI solution (BylomaX HR-16NN, manufactured by Toyobo Co., Ltd.) was applied to the entire surface of the heat-generating layer 20b by ring coating. It was fired at 230 °C for 30 minutes to form a protective layer 20e with a central thickness of 40 μm and an end thickness of 40 μm.

[0116] Next, a primer (product name: DY39-051A / B, manufactured by Dow Corning Toray Co., Ltd.) was applied to the outer peripheral surface of the protective layer 20e so as to be approximately uniform with a dry weight of 20 mg. After drying the solvent, baking treatment was performed in an electric furnace set at 160 °C for 30 minutes. On this primer, a silicone rubber composition layer with a thickness of 250 μm was formed by the ring coating method. After primary cross-linking at 160 °C for 1 minute, secondary cross-linking was performed at 200 °C for 30 minutes to form an elastic layer 20c.

[0117] The following silicone rubber composition was used. As the organopolysiloxane having an alkenyl group as component (a), vinylated polydimethylsiloxane (product name: DMS-V41, manufactured by Gelest Inc., number average molecular weight 68000 (polystyrene conversion), molar equivalent of vinyl group 0.04 mmol / g) having at least 2 or more vinyl groups in one molecule was prepared. Further, as the organopolysiloxane having an Si-H group as component (b), methylhydrogenpolysiloxane (trade name: HMS-301, manufactured by Gelest, number average molecular weight 1300 (polystyrene conversion), molar equivalent of Si-H group 3.60 mmol / g) having at least 2 or more Si-H groups in one molecule was prepared. With respect to 100 parts by mass of component (a), 0.5 part by mass of component (b) was added and thoroughly mixed to obtain an addition-curable silicone rubber stock solution. Furthermore, a catalytic amount of a trace amount of a catalyst for addition-curing reaction (platinum catalyst: platinum carbonylcyclovinylmethylsiloxane complex) and an inhibitor as component (c) were added and thoroughly mixed. To this addition-curable silicone rubber stock solution, high-purity spherical alumina (trade name: Alnavis CB-A10S; manufactured by Showa Titanium Co., Ltd.) as a thermally conductive filler was blended and kneaded so that the volume ratio was 45% based on the elastic layer. And an addition-curable silicone rubber composition having a JIS K 6253A-compliant durometer hardness of 10° after curing was obtained.

[0118] Next, an addition-curable silicone rubber adhesive (trade name: SE1819CV A / B, manufactured by Dow Corning Toray Co., Ltd.) for forming the adhesive layer 20f was applied substantially uniformly on the obtained elastic layer 20c so that the thickness was approximately 20 μm. A fluororesin tube (trade name: NSE, manufactured by Gunze Co., Ltd.) having an inner diameter of 29 mm and a thickness of 50 μm for forming the surface layer 20d was laminated while expanding the diameter. Thereafter, by uniformly handling the belt surface from above the fluororesin tube, the excess adhesive was extruded from between the elastic layer 20c and the fluororesin tube so as to be thinned to about 5 μm. Next, it was heated at 200 °C for 30 minutes to cure the adhesive, the fluororesin tube was fixed on the elastic layer 20c, and finally both ends were cut so that the length became 240 mm to obtain a fixing rotating body.

[0119] [Example 2] A fixing rotating body was produced in the same manner as in Example 1 except that the firing temperature of the heat generating layer 20b was 250 °C.

[0120] [Example 3] A fixing rotator was produced in the same manner as in Example 1, except that the firing temperature of the heating layer 20b was set to 200°C.

[0121] [Example 4] A fixing rotator was produced in the same manner as in Example 1, except that no protective layer was formed.

[0122] [Comparative Example 1] It was produced in the same manner as in Example 1, except that tellurium oxide was not formed in the treatment of the heating layer.

[0123] [Comparative Example 2] It was produced in the same manner as in Example 2, except that tellurium oxide was not formed in the treatment of the heating layer.

[0124] [Comparative Example 3] It was produced in the same manner as in Example 3, except that tellurium oxide was not formed in the treatment of the heating layer.

[0125] (Evaluation: Porosity Evaluation) For Examples 1 to 4 and Comparative Examples 1 to 3, cross-sectional observation of the heating layer 20b was performed by the above-described method, and the porosity was calculated. The results are shown in Table 1.

[0126] (Evaluation: Content Evaluation of Tellurium Oxide) Confirmation of whether tellurium oxide was contained in the heating layer was performed by the following method. In Examples 1 to 4, a peak of tellurium oxide was confirmed over the entire thickness of the heating layer, but it was not observed in Comparative Examples 1 to 3.

[0127] First, a sample for evaluation was prepared. The resin layer such as the protective layer formed on the surface of the heating layer was removed with a cutter to obtain a sample in which the heating layer 20b was formed on the base layer. The sample was cut out to a size of 10 mm in length and 10 mm in width. The cut-out sample was placed on a sample stage called a platen for X-ray Photoelectron Spectroscopy and introduced into an X-ray photoelectron spectrometer under ultra-high vacuum. The X-ray photoelectron spectrometer was measured in an environment at 23°C.

[0128] The X-ray photoelectron spectrometer used was the PHI Qunatera I manufactured by ULVAC-PHI I. An AlKα ray was used as the X-ray source, and depth-direction analysis using Ar sputtering was performed. The X-ray irradiation conditions were 200 μm, 50 W, and 15 kV, and the pass energy of the detector was set to 112 eV, and the Time per Step was set to 10 ms. The Ar sputtering was set to process a range of 2 mm × 2 mm at an acceleration voltage of 4 kV. The processing rate was 37.5 nm / min. The above-mentioned heating layer with a known film thickness was dug under the same conditions, and when the ratio of silver in the measured elements reached 50%, it was judged that the film had disappeared, and the processing rate was calculated from the time taken.

[0129] The measured elements were C, N, O, Si, Cl, Ag, and Te. The orbits and measurement energy ranges of the measured elements are as follows. For C, C1s was measured in the range of 278 - 298 eV, for N, N1s was measured in the range of 391 - 411 eV, for O, O1s was measured in the range of 523 - 543 eV, for Si, Si2p was measured in the range of 94 - 114 eV, for Cl, Cl2p was measured in the range of 193 - 213 eV, for Ag, Ag3d was measured in the range of 362 - 382 eV, and for Te, Te3d was measured in the range of 567 - 589 eV. The number of measurement repetitions was 10 times for C1s, 10 times for N1s, 10 times for O1s, 10 times for Si2p, 20 times for Cl2p, 10 times for Ag3d, and 15 times for Te3d, respectively.

[0130] For the depth-direction measurement, under the above processing conditions, after measuring the surface of the heating layer, Ar sputtering was performed for 10 minutes and the measurement was repeated 10 times. Since the processing rate was 37.5 nm / min, it means that the analysis was performed at a pitch of 375 nm in the depth direction. The obtained depth-direction spectra were analyzed using MultiPak, the analysis software manufactured by UlVAC-PHI. First, peak shift correction was performed on all the obtained spectra. The method is as follows. The top of the highest-intensity peak that could be confirmed around 368 eV in the 3d spectrum of Ag was set as Ag3d5 / 2 so that it became 368.3 eV. This value was referred to the X-ray Photoelectron Spectroscopy (6th Edition) published by Maruzen Co., Ltd.

[0131] Next, for each measurement spectrum, a background range was determined, the integrated intensity was calculated, and the result of dividing it by the device-specific sensitivity coefficient (Corrected RSF) was taken as the intensity for each. The Shirley method was used for background setting. The background setting range and the elements and orbits using the device-specific sensitivity coefficient are as follows. For C, it is C1s at 280.0 - 292.0 eV, for N it is N1s at 396.5 - 404.0 eV, for O it is O1s at 526.0 - 538.0 eV, for Si it is Si2p at 99.7 - 108.0 eV, for Cl it is Cl2p at 194.0 eV - 204.0 eV, for Ag it is Ag3d at 364.0 - 380.0 eV, and for Te it is Te3d3 / 2 at 580.0 - 588.5 eV. For the convenience of analysis, a deviation of ±0.1 eV was allowed when the exact ranges did not match. Regarding Te, since the 3d 5 / 2 of Te overlaps with Ag3p3 / 2, only the Te3d3 / 2 orbit was used.

[0132] The intensity calculated for each was divided by the intensity of the measured element and expressed as a percentage, which was taken as the element ratio. Note that the ratio is at%, that is, atomic%. As an example, the Te ratio is shown. Te ratio (at%) = (Te intensity) / (C intensity + N intensity + O intensity + Si intensity + Cl intensity + Ag intensity + Te intensity) × 100 That is.

[0133] Since the detection limit of X-ray photoelectron spectroscopy is 0.1 at% as described in the above X-ray photoelectron spectroscopy (6th edition), it was determined that the Te element was present when Te was 0.1 at% or more by the above calculation method.

[0134] The determination of whether TeO2 was present further referred to the literature (Analysis of Te and TeO2 on CdZnTe Nuclear Detectors Treated with Hydrogen Bromide and Ammonium-Based Solutions). In this literature, the 3d3 / 2 derived from Te is 583.5 eV, and the 3 It is described that the peak top of d3 / 2 is formed at 586.5 eV. Therefore, after forming the background using the Shirley method in the range of 580.0 - 588.5 eV, peaks were placed at 583.5 eV and 586.5 eV, and automatic fitting was performed. The intensity ratio of Te and TeO2 is calculated by automatic fitting. The product of the intensity ratio of TeO2 and the intensity of the Te element is regarded as the proportion of TeO2 in Te. If this value is 0.1 or more, it is determined that TeO2 exists inside the heating layer. And in each analysis every 375 nm, if the proportion of the Ag element exceeds 50.0 at% among all elements and the proportion of TeO2 in Te is 0.1 or more, it is determined that peaks of tellurium oxide are confirmed across the entire thickness of the heating layer.

[0135] (Evaluation: High-temperature storage) The fixing rotators obtained in Examples 1 - 4 and Comparative Examples 1 - 3 were stored at 240 °C for 200 hours under atmospheric pressure. This storage temperature was set from the assumed over-temperature when the fixing rotator was actually incorporated into the fixing device and used in a special usage environment (when continuously printing small sizes). When a fixing rotator under the same conditions as Comparative Example 1 was heated at 200 °C for 200 hours, the resistance increase was within 5% in the following resistance value measurement.

[0136] (Evaluation: Resistance value measurement) The resistance value evaluation was performed using contact resistance measurement. The fabricated fixing rotator was cut in half, with one half used for initial resistance evaluation and the other half for evaluation after heating. During resistance measurement, the resin layer part was peeled off with a cutter, and measurement was performed by the four-terminal resistance measurement method. The details of the resistance measurement are described below. In the resistance measurement, two instruments were used: a resistance meter 3541 manufactured by HIOKI and an FPC-GS-500 probe manufactured by Form Factor. The mode was set to the low-power mode, and the probe was pressed against the heating layer so that the distance between the respective sense probes was 20 mm to measure the resistance value. The conversion to volume resistivity was performed from the width and film thickness of the heating layer. The same measurements were taken before and after heating. Using the pre-heating values as the initial values, the increase in volume resistivity from the initial values was evaluated, with an increase of less than 5% marked as ○ and an increase of 5% or more marked as ×.

[0137]

Table 1

[0138] From the results in Table 1, the presence of tellurium oxide throughout the total thickness of the heating layer suppresses the increase in resistance due to heating at 240°C and can suppress the occurrence of image defects. The present disclosure relates to the following configurations and methods.

[0139] The present disclosure relates to the following configurations and methods. (Configuration 1) A rotator for fixing, The rotator for fixing, comprises a base material containing resin, a heating layer on the base material, and is provided with the heating layer extends in the circumferential direction of the outer peripheral surface of the base material, the heating layer contains silver, in the cross-section of the heating layer along the circumferential direction, at least one pore exists, when the heating layer is analyzed by an X-ray photoelectron spectrometer at a pitch of 375 nm in the depth direction from the surface on the side opposite to the side facing the base material, a peak of tellurium oxide is confirmed throughout the total thickness of the heating layer. The rotator for fixing is characterized by this. (Configuration 2) The rotator for fixing according to Configuration 1, wherein the heating layer is a fired body of silver nanoparticles. (Configuration 3) The rotator for fixing according to Configuration 1 or 2, wherein the ratio of the pores in the cross-section of the heating layer, which is measured by observing the cross-section obtained by cutting the heating layer sampled from the rotator for fixing in the thickness direction, is 15 - 50 area%. (Configuration 4) A fixing device comprising the rotator for fixing according to any one of Configurations 1 to 3, and an induction heating device for generating heat by induction heating the rotator for fixing. (Configuration 5) An electrophotographic image forming apparatus, wherein the electrophotographic image forming apparatus, has an image carrier for carrying a toner image, a transfer device for transferring the toner image to a recording material, a fixing device for fixing the transferred toner image to the recording material, and is provided with, wherein the fixing device is the fixing device described in Configuration 4. An electrophotographic image forming apparatus characterized by this. (Method 6) A method for manufacturing a rotating body for fixing according to any one of Configurations 1 to 3, wherein the manufacturing method, includes a step of preparing a laminate in which the heat generating layer is formed on the base material, a step of impregnating a tellurium solution containing tellurium from a surface on the side opposite to the side of the heat generating layer facing the base material, and a step of heating to 200 °C or higher after impregnating the tellurium solution. A method for manufacturing a rotating body for fixing, characterized by including this. (Configuration 7) A conductive member having a base material and a heat generating layer on the base material, wherein the heat generating layer contains silver, at least one pore exists in a cross section in the thickness direction of the heat generating layer, when the heat generating layer is analyzed by an X-ray photoelectron spectrometer at a pitch of 375 nm in the depth direction from a surface on the side opposite to the side of the heat generating layer facing the base material, a peak of tellurium oxide is confirmed over the entire thickness of the heat generating layer. A conductive member characterized by this.

Industrial Applicability

[0140] As described above, the present disclosure can obtain a rotating body for fixing having excellent durability even in a special environment such as continuously printing on small-sized paper.

Explanation of Signs

[0141] 1 Image forming apparatus, 15 Fixing device, 20 Rotating member for fixing, 20a Base material, 20b Heat generating layer, 20c Elastic layer, 20d Surface layer, 20e Protective layer, 20f Adhesive layer, 21 Pressing roller

Claims

1. A rotator for fixing, comprising: The rotator for fixing: A base material containing resin; and A heating layer on the base material; The heating layer extends in the circumferential direction of the outer peripheral surface of the base material, The heating layer contains silver, In the cross section of the heating layer along the circumferential direction, at least one pore exists, When the heating layer is analyzed by an X-ray photoelectron spectrometer at a pitch of 375 nm in the depth direction from the surface on the side opposite to the side facing the base material, a peak of tellurium oxide is confirmed over the entire thickness of the heating layer. A rotator for fixing, characterized by this.

2. The rotator for fixing according to claim 1, wherein the heating layer is a fired body of silver nanoparticles.

3. The rotator for fixing according to claim 1, wherein the ratio of the pores in the cross section of the heating layer, which is measured by observing the cross section obtained by cutting the heating layer sampled from the rotator for fixing in the thickness direction, is 15 to 50 area%.

4. A fixing device, comprising: The rotator for fixing according to any one of claims 1 to 3; and An induction heating device that generates heat by induction heating the rotator for fixing.

5. An electrophotographic image forming apparatus, comprising: An image carrier that supports a toner image; A transfer device that transfers the toner image to a recording material; and A fixing device that fixes the transferred toner image to the recording material, The fixing device is the fixing device according to claim 4. An electrophotographic image forming apparatus, characterized by this.

6. A method for manufacturing a rotator for fixing according to any one of claims 1 to 3, comprising: A step of preparing a laminate in which the heating layer is formed on the base material; A step of impregnating a tellurium solution containing tellurium from the surface on the side opposite to the side facing the base material of the heating layer; and A step of heating to 200 °C or higher after impregnating the tellurium solution. A method for manufacturing a rotator for fixing, characterized by including these steps.

7. A conductive member having a base material and a heating layer on the base material, The heating layer contains silver, In the cross section in the thickness direction of the heating layer, at least one pore exists, When the heating layer is analyzed by an X-ray photoelectron spectrometer at a pitch of 375 nm in the depth direction from the surface on the side opposite to the side facing the base material, a peak of tellurium oxide is confirmed over the entire thickness of the heating layer. A conductive member, characterized by this. ​ ​ ​ ​

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