CN117930611A - Fixing rotating member, fixing device and electrophotographic image forming device - Google Patents

Abstract

The present invention relates to a fixing rotating member, a fixing device, and an electrophotographic image forming device. A fixing rotating member includes: a substrate containing a resin; a conductive layer on the substrate; and a resin layer on a surface of the conductive layer, the surface being opposite to a side of the conductive layer facing the substrate, the conductive layer extending in a circumferential direction of an outer peripheral surface of the substrate, the conductive layer containing silver, and having a through hole in a thickness direction thereof, wherein at least a portion of the through hole is penetrated by a resin constituting at least a portion of the resin layer.

Description

Fixing rotating member, fixing device and electrophotographic image forming device

Technical Field

The present disclosure relates to a fixing rotating member used in a fixing device of an electrophotographic image forming apparatus such as an electrophotographic copying machine or a printer, and to the fixing device and the electrophotographic image forming apparatus.

Background technique

In a fixing device installed in an electrophotographic image forming device such as an electrophotographic copier or printer, a recording material carrying an unfixed colorant image is usually heated while being conveyed at a roller gap formed between a heated fixing rotating member and a pressure roller in contact with the fixing rotating member, whereby the colorant image is fixed to the recording material.

A fixing device that relies on an electromagnetic induction heating scheme and has a conductive layer on a fixing rotating member so that the conductive layer can directly generate heat has been developed and put into practical use. The electromagnetic induction heating type fixing device has an advantage in that it provides a short warm-up time.

As a fixing component used in such a fixing device, Japanese Patent Application Publication No. 2021-051136 discloses a fixing component comprising: a base layer containing a resin; an electromagnetic induction metal layer containing copper and arranged on the outer peripheral surface of the base layer; a metal protective layer containing nickel and arranged in contact with the electromagnetic induction metal layer; and an elastic layer arranged on the outer peripheral surface of the metal protective layer.

Summary of the invention

At least one aspect of the present disclosure is to provide a fixing rotating member having excellent durability, and the fixing rotating member includes a conductive layer containing silver, and the conductive layer exhibits high adhesion to a substrate. In addition, at least one aspect of the present disclosure is to provide a fixing device that helps to provide a stable high-quality electrophotographic image. In addition, at least one aspect of the present disclosure is to provide an electrophotographic image forming device capable of forming a stable high-quality electrophotographic image.

According to at least one aspect of the present disclosure, there is provided a fixing rotating member, comprising:

a substrate comprising a resin;

A conductive layer on the substrate; and

a resin layer on a surface of the conductive layer, the surface being opposite to a side of the conductive layer facing the substrate,

The conductive layer extends along the circumferential direction of the outer peripheral surface of the substrate.

The conductive layer comprises silver,

The conductive layer has a through hole in the thickness direction thereof;

At least a portion of the through hole is infiltrated by a resin constituting at least a portion of the resin layer.

Furthermore, according to at least one aspect of the present disclosure, there is provided a fixing apparatus including the above-mentioned fixing rotating member and an induction heating device that generates heat in the fixing rotating member by induction heating.

In addition, according to at least one aspect of the present disclosure, there is provided an electrophotographic image forming apparatus, wherein

The electrophotographic image forming apparatus comprises:

an image bearing member bearing a toner image;

Transfer means for transferring the toner image to a recording material; and

a fixing device for fixing the transferred toner image to the recording material,

The fixing device is the above-mentioned fixing device.

Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram showing the form of a conductive layer;

2 is a schematic diagram of an electrophotographic image forming apparatus according to an embodiment;

3 is a schematic diagram showing a cross-sectional configuration of a fixing device according to the embodiment;

4 is a schematic diagram showing a cross-sectional configuration of a fixing device according to the embodiment;

5 is a schematic diagram of a magnetic core and an exciting coil of a fixing device according to the embodiment;

6 is a diagram showing a magnetic field formed when a current is passed through an exciting coil according to an embodiment;

7 is a cross-sectional structural diagram of a fixing rotating member according to the embodiment;

8A to 8C are a set of schematic diagrams of a formation mechanism of holes penetrating a conductive layer of a fixing rotating member in a thickness direction according to an embodiment; and

9 is a cross-sectional image of a substrate, a conductive layer, and a resin layer in Example 4 (a photograph in place of a figure).

Detailed ways

In the present disclosure, unless otherwise specified, the description "from XX to YY" and "XX to YY" indicating a numerical range means a numerical range including the lower limit and the upper limit of the range as endpoints. In the case of describing the numerical range in sections, the upper and lower limits of each numerical range can be arbitrarily combined. In the present disclosure, for example, words such as "at least one selected from the group consisting of XX, YY and ZZ" include XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, and a combination of XX, YY and ZZ.

In recent years, as the speed of printers has increased, the durability of the conductive layer has been required to be further improved. In the case where the electromagnetic induction layer contains copper, since copper is easily oxidized, the electromagnetic induction layer must be protected from oxidation of copper by covering the electromagnetic induction layer with a layer of metal such as nickel, as disclosed in Japanese Patent Application Publication No. 2021-051136.

Therefore, the inventors have studied the use of silver, which is relatively resistant to oxidation and exhibits high conductivity, as a constituent material of the electromagnetic induction layer. In this method, the inventors found that when an electromagnetic induction layer (heat-generating layer) composed of silver is formed on a substrate by silver plating, the adhesion of the silver plating to the substrate is not necessarily sufficient, and there is still room for improvement in further improving the durability of the fixing member.

The fixing rotating member is repeatedly strained in the roller nip portion under heating, so the fixing rotating member needs to show long-term durability. Here, interlayer peeling is a failure mode that affects durability. Specifically, peeling between a substrate made of resin and a conductive layer made of silver and between a conductive layer and a resin layer formed on the conductive layer occurs due to the difference in stress acting on the substrate, the conductive layer, and the resin layer. When such a defect occurs, cracks or the like are generated in the conductive layer starting from the defect, and conductivity is impaired.

The inventor's research has revealed that by providing holes that penetrate the conductive layer in the thickness direction so that the resin serving as a protective layer penetrates into the through holes, as shown in Figure 1, the substrate, the conductive layer and the resin layer become integrated with each other and are therefore firmly bonded to each other, thereby suppressing the occurrence of peeling and improving durability.

Next, a fixing rotating member having a conductive layer, and a fixing device and an electrophotographic image forming apparatus configured using the fixing rotating member are explained in detail based on the following specific configuration.

However, the size, material, shape, relative arrangement, etc. of the components described in this aspect will be appropriately modified according to the construction of the component to which the present disclosure is applied and depending on various conditions. That is, the scope of the present disclosure is not meant to be limited to the following aspects. In the following explanation, features that cause the same function are represented by the same figure mark in the drawings, and the explanation thereof may be omitted.

(Electronic Photographic Image Forming Apparatus)

An electrophotographic image forming apparatus (hereinafter also simply referred to as "image forming apparatus") includes an image bearing member that bears a toner image, a transfer device that transfers the toner image onto a recording material, and a fixing device that fixes the transferred toner image to the recording material.

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 in which a fixing device (image heating means) 15 is installed according to the embodiment. A box 2 is accommodated at the bottom of the printer 1 so that it can be pulled out. Sheets P as recording materials are stacked and accommodated in the box 2. The sheets P in the box 2 are fed to the registration roller 4 while being separated one by one by the separation roller 3.

Various sheets of different sizes and materials, for example, paper such as plain paper and thick paper, surface-treated sheet materials such as plastic film, cloth, coated paper, etc., and sheet materials of special shapes such as envelopes and index paper, can be used as the sheet P as a recording material.

The printer 1 includes an image forming unit 5 as an image forming means, in which image forming stations 5Y, 5M, 5C, 5K corresponding to respective colors of yellow, magenta, cyan and black are arranged in horizontal rows. The image forming station 5Y is provided with a photosensitive drum 6Y which is an image bearing member (electrophotographic photosensitive member) for bearing a toner image, and a charging roller 7Y as a charging means for uniformly charging the surface of the photosensitive drum 6Y.

The scanner unit 8 is provided below the image forming unit 5. Each scanner unit 8 forms an electrostatic latent image on the photosensitive drum 6Y by projecting a laser beam modulated by switching according to a digital image signal generated by an image processing means and having been input from an external device (not shown) such as a computer based on image information, onto the photosensitive drum 6Y. The image forming station 5Y also has a developing roller 9Y as a developing means for development, which develops the toner of the electrostatic latent image adhered to the photosensitive drum 6Y in the form of a toner image (toner image), and a primary transfer unit 11Y that transfers the toner image on the photosensitive drum 6Y to the intermediate transfer belt 10.

The toner images similarly formed according to similar processes at the other image forming stations 5M, 5C, 5K are transferred superimposedly onto the toner image on the intermediate transfer belt 10, which already has the toner image transferred thereto at the primary transfer unit 11Y. As a result, a full-color toner image is formed on the intermediate transfer belt 10. The full-color toner image is transferred onto the sheet P at the secondary transfer unit 12 as a transfer means. The primary transfer unit 11Y and the secondary transfer unit 12 are examples of fixing devices that fix the transferred toner image onto the recording material.

Thereafter, the toner image transferred onto the sheet P (recording material) passes through the fixing device 15 and is fixed as a fixed image. The sheet P passes through the discharge conveying unit 13 and is discharged and stacked on the stacking unit 14.

The image forming unit 5 is an example of image forming means. Although the primary transfer unit 11Y and the secondary transfer unit 12 are shown here as examples of fixing devices, the fixing devices may be, for example, fixing devices of a direct transfer type in which a toner image is directly transferred from an image bearing member to a sheet P. In addition, the image forming device may have a monochrome configuration in which only one color of toner is used.

(Fixing equipment)

The fixing device 15 of the present embodiment is an induction heating type fixing device (image heating device), which generates heat for the fixing rotating member by electromagnetic induction. FIG. 3 shows a cross-sectional structure of the fixing device 15, and FIG. 4 is a stereoscopic view of the fixing device 15. The housing of the fixing device 15 and the like are omitted in FIG. 3 and FIG. 4. In the following description, the length direction X1 of the member constituting the fixing device 15 represents a direction perpendicular to the conveying direction of the recording material and the thickness direction of the recording material.

The fixing device 15 includes a fixing rotating member 20, a film guide 25, a pressure roller 21, a pressure stay 22, a magnetic core 26, an exciting coil 27 (Figure 5), a thermistor 40 and a current sensor 30. The fixing device 15 heats the recording material on which the image is formed to fix the image on the recording material. The fixing rotating member 20 is a rotating member of the present embodiment, and the pressure roller 21 is a counter member of the present embodiment. The exciting coil 27 is used as a magnetic field generating means of the present embodiment. The details of the fixing rotating member will be further described.

The fixing rotating member 20 includes a conductive layer 20b as a heat generating layer on a substrate. The conductive layer 20b can generate heat, for example, by induction current. The conductive layer (heat generating layer) 20b is formed into individual rings electrically connected in the circumferential direction, thereby forming a heat generating pattern in which heat generating rings 201 (FIG. 4) electrically separated from each other in the longitudinal direction X1 (the rotation axis direction of the fixing rotating member 20) are arranged side by side in the longitudinal direction.

That is, the conductive layer 20b is divided into a plurality of annular areas which are connected in the circumferential direction of the fixing rotating member 20 but are not electrically conductive to each other in the rotation axis direction of the fixing rotating member 20. Each heat generating ring 201 as a constituent element of the heat generating pattern is formed to be uniformly wide in the length direction X1.

The pressure roller 21 as a counter member (pressure member) facing the fixing rotating member 20 has a metal core 21a, an elastic layer 21b concentrically surrounding the metal core and integrally formed into a roller shape covering the metal core, and a release layer 21c provided on the surface layer. The elastic layer 21b is preferably made of a material having good heat resistance such as silicone rubber, fluororubber or fluorosilicone rubber, etc. Both ends of the metal core 21a in the length direction are rotatably held between metal plates (not shown) on the chassis side of the device via conductive bearings.

As shown in FIG. 4 , the pressurizing springs 24 a , 24 b are compressed between the respective ends of the pressure stay 22 in the longitudinal direction and the respective spring receiving members 23 a , 23 b on the device chassis side, with the result that a downward thrust is applied to the pressure stay 22 .

In the fixing device 15 of the present embodiment, a total pressure of about 100 N to 300 N (about 10 kgf to about 30 kgf) is applied. As a result, the lower surface of the film guide 25 made of heat-resistant resin PPS or the like and the upper surface of the pressure roller 21 are pressed against each other with the inserted fixing rotating member 20 as a cylindrical rotating member sandwiched therebetween, thereby forming a fixing nip portion N having a predetermined width.

The film guide 25 functions together with the pressure roller 21 as a nip portion forming member that forms a nip portion that pinches and conveys the recording material carrying the toner image via the fixing rotating member 20 therebetween.

Here, PPS is polyphenylene sulfide.

The pressure roller 21 is rotationally driven clockwise by an unillustrated driving means so that a counterclockwise rotational force acts on the fixing rotational member 20 due to friction with the outer surface of the fixing rotational member 20. The fixing rotational member 20 rotates while sliding on the film guide 25.

5 is a schematic diagram of the magnetic core 26 and the exciting coil 27 of FIG. 3 , wherein the fixing rotating member 20 is indicated by a dotted line, for illustrating the positional relationship relative to the fixing rotating member 20. The induction heating device for heating the fixing rotating member 20 by electromagnetic induction in the induction heating type fixing device may include the magnetic core 26 and the exciting coil 27.

The exciting coil 27 is disposed inside the fixing rotating member 20. The exciting coil 27 having a spiral shape, whose spiral axis is substantially parallel to the direction of the rotating axis of the fixing rotating member 20, forms an alternating magnetic field, which causes the conductive layer 20b to generate heat by electromagnetic induction. The language "substantially parallel" here not only means a state in which the two axes are completely parallel to each other, but also means that a slight deviation from this state is allowed as long as the conductive layer can generate heat by electromagnetic induction.

The magnetic core 26 is disposed in the spiral shape while extending in the rotation axis direction of the fixing rotation member 20 so as not to form a loop outside the fixing rotation member 20. The magnetic core 26 induces magnetic lines of force of the alternating magnetic field.

In Fig. 5, a magnetic core 26 is inserted through a hollow portion of a fixing rotating member 20 which is a tubular rotating member. An exciting coil 27 is spirally wound on the outer periphery of the magnetic core 26 while extending in the length direction of the fixing rotating member 20. The magnetic core 26 has a cylindrical shape and is fixed by fixing means not shown so as to be located substantially at the center of the fixing rotating member 20 in a cross section viewed in the length direction (see Fig. 3).

The magnetic core 26 disposed inside the exciting coil 27 has the function of guiding the magnetic lines of force (magnetic flux) of the alternating magnetic field generated by the exciting coil 27 to the inner side of the conductive layer 20b of the fixing rotating member 20, thereby forming a path (magnetic path) for the magnetic lines of force. The material of the magnetic core 26, which is a ferromagnetic body, is preferably a material having a small hysteresis loss and a high relative magnetic permeability, such as at least one soft magnetic body having a high magnetic permeability selected from the group consisting of, for example, fired ferrite and ferrite resin.

Preferably, the core 26 is shaped so that more than 70% of the magnetic flux emitted from one longitudinal end of the core 26 in the rotation axis direction passes through the outside of the conductive layer 20 b and returns to the other longitudinal end of the core 26 .

The cross-sectional shape of the magnetic core 26 may be any shape as long as the magnetic core 26 can be accommodated in the hollow portion of the fixing rotating member 20; the cross-sectional shape of the magnetic core 26 is not necessarily circular, but is preferably converted into a shape with the largest possible cross-sectional area. The magnetic core 26 in this embodiment has a diameter of 10 mm and a length in the longitudinal direction of 280 mm.

The exciting coil 27 is formed by spirally winding 20 turns of a copper wire (single conductor) having a diameter of 1 to 2 mm and coated with heat-resistant polyamide-imide around the magnetic core 26. The exciting coil 27 is wound around the magnetic core 26 in a direction intersecting with the rotation axis direction of the fixing rotating member 20. Therefore, when a high-frequency alternating current passes through the exciting coil 27, an alternating magnetic field is generated in a direction parallel to the rotation axis direction, so that an induced current (circulating current) flows in the heat generating ring 201 of the conductive layer 20b of the fixing rotating member 20 according to the following principle, resulting in heat generation.

As shown in Fig. 3 and Fig. 4, the thermistor 40 as a temperature detection means for detecting the temperature of the fixing rotating member 20 is composed of a spring plate 40a and a thermistor element 40b. The spring plate 40a is a supporting member having spring elasticity and extending toward the inner surface of the fixing rotating member 20. The thermistor element 40b as a temperature detection element is mounted on the front end 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.

The thermistor 40 is mounted by being fixed to the film guide 25 at a substantially central position in the length direction of the fixing rotating member 20. The thermistor element 40b is pressed against the inner surface of the fixing rotating member 20 and is held in contact with the fixing rotating member 20 by the spring elasticity of the spring plate 40a. The thermistor 40 may be provided on the outer peripheral side of the fixing rotating member 20.

The current sensor 30 constituting the conduction monitoring means for monitoring the conduction in the circumferential direction of the conductive layer 20b is disposed at the same position as the position of the thermistor 40 in the length direction of the fixing device 15. That is, from among the plurality of heat generating rings 201 constituting the heat generating pattern of the fixing rotating member 20, the current sensor 30 monitors the conduction state of the heat generating ring 201 at the position where the thermistor element 40b contacts with it.

(Heating principle)

Next, the heating principle of the fixing rotating member 20 in the induction heating type fixing device 15 is explained. FIG6 is a conceptual diagram showing the moment when the current in the exciting coil 27 increases in the direction of the arrow I0. The exciting coil 27 inserted in the fixing rotating member 20 generates an alternating magnetic field in the rotation axis direction of the fixing rotating member 20 due to the AC current flowing through the exciting coil 27, so the exciting coil 27 is used as a magnetic field generating means for generating an induced current I in the circumferential direction of the fixing rotating member 20.

The magnetic core 26 is used as a member for forming a magnetic circuit by guiding the magnetic force lines B (dashed lines in the figure) generated by the exciting coil 27. In a general induction heating method, the magnetic force lines pass through the conductive layer to generate eddy currents; in contrast, in the present embodiment, the magnetic force lines B form a loop outward from the fixing rotating member. That is, the conductive layer 20b generates heat mainly due to the induced current induced by the magnetic force lines that are emitted from one longitudinal end of the magnetic core 26, pass through the outside of the conductive layer 20b, and return to the other longitudinal end of the magnetic core 26. As a result, even when the thickness of the conductive layer is small, for example, 4 μm or less, heat can be effectively generated.

When an alternating magnetic field is formed by the exciting coil 27, an induced current I according to Faraday's law flows through the heat ring 201 of the conductive layer 20b of the fixing rotating member 20. Faraday's law states that "when the magnetic field in a circuit changes, an induced electromotive force is generated thereon, causing a current to flow in the circuit, and the induced electromotive force is proportional to the change in the magnetic flux perpendicular to the circuit over time."

Regarding the heating ring 201c located in the center portion in the longitudinal direction of the magnetic core 26 shown in Fig. 6, it is considered that when a high-frequency alternating current is caused to flow through the exciting coil 27, an induced current I flows in the heating ring 201c. When this high-frequency alternating current is caused to flow, an alternating magnetic field is formed inside the magnetic core 26. According to the following expression, the induced electromotive force acting on the heating ring 201c is proportional to the change in the magnetic flux perpendicularly passing through the inner side of the heating ring 201c with time.

V: Induced electromotive force

N: Number of coil turns

The change of magnetic flux passing vertically through the circuit (heat generating ring 201c) in a small time increment ΔT

The induced electromotive force V causes the flow of an induced current I, which is a circulating current around the heat generating ring 201c; the heat generating ring 201c generates heat thereon by Joule heat generated by the induced current I.

However, when the heating ring 201c is disconnected, the induced current I no longer flows and the heating ring 201c does not generate heat.

(1) Simplified structure of the fixing rotating member

Next, details about the fixing rotating member of the present embodiment will be explained with reference to the drawings.

The fixing rotating member according to one aspect of the present disclosure may be, for example, a rotatable member such as an endless belt.

Fig. 7 is a circumferential cross-sectional view of a fixing rotating member. As shown in Fig. 7, the fixing rotating member includes a substrate 20a, a conductive layer 20b on the outer surface of the substrate 20a, and a resin layer 20e on the outer surface of the conductive layer. As required, an elastic layer 20c and a surface layer (release layer) 20d may be provided on the resin layer 20e, and an adhesive layer 20f may be provided between the elastic layer 20c and the surface layer 20d.

(2) Base material

The material of the substrate 20a is not particularly limited as long as it is a layer containing at least a resin. That is, the substrate 20a contains a resin. When the belt is used in an electromagnetic induction type fixing device, the substrate 20a is preferably a layer that maintains high strength and has little change in physical properties in a state where the conductive layer is heated. Therefore, the substrate 20a preferably contains a heat-resistant resin as a main component, and it is preferred that the substrate 20a is composed of a heat-resistant resin.

The resin contained in the substrate 20a (preferably a resin constituting at least a part of the substrate) preferably includes at least one selected from the group consisting of polyimide (PI), polyamide-imide (PAI), modified polyimide and modified polyamide-imide. More preferably, the resin contained in the substrate 20a is at least one selected from the group consisting of polyimide and polyamide-imide. Among the foregoing, polyimide is particularly preferred. In the present disclosure, the term main component means the component with the highest content among the components constituting the object (here, the substrate).

Modifications of the modified polyimide and the modified polyamide-imide include, for example, siloxane modification, carbonate modification, fluorine modification, urethane modification, triazine modification, and phenol modification.

In order to improve thermal insulation and strength, a filler may be added to the base material 20a.

The shape of the substrate can be appropriately selected, for example, according to the shape of the fixing rotating member, and various shapes such as an endless belt shape, a hollow cylindrical shape, or a film shape can be adopted.

In the case of a fixing belt, the thickness of the base material 20a is preferably, for example, 10 to 100 μm, more preferably 20 to 60 μm. Setting the thickness of the base material 20a within the above range allows the strength and flexibility to be produced at a high level.

In the case where the inner circumference of the fixing belt contacts another member, for example, a layer for preventing wear of the inner circumference of the fixing belt and/or a layer for enhancing sliding properties with another member may be provided on the surface of the substrate 20a on the opposite side to the side facing the conductive layer 20b.

In order to improve adhesion and wettability with the conductive layer 20b, the outer peripheral surface of the substrate 20a is subjected to surface roughening treatment such as sandblasting, and/or modification treatment such as treatment with ultraviolet rays or plasma, or chemical etching.

(3) Conductive layer

The conductive layer 20b is a layer that generates heat when electricity is supplied. According to the principle of generating heat by induction heating using an excitation coil, when an alternating current is supplied to an excitation coil provided near a fixing rotating member, a magnetic field is induced, and due to the induced magnetic field, a current is generated in the conductive layer 20b of the fixing rotating member, so that heat is generated due to Joule heat.

Silver, which has a low volume resistivity and is not easily oxidized, is preferably used as a material for the conductive layer 20b. The conductive layer 20b contains silver. The conductive layer 20b may contain a metal other than silver as long as the effect of the present disclosure is not impaired thereby. However, the purity of the silver constituting at least a portion of the conductive layer 20b is preferably 90% by mass or more, more preferably 99% by mass or more, and particularly preferably 99.9% by mass or more. The upper limit of the silver content is not particularly limited, but, for example, the upper limit is 100% by mass or less.

In the fixing member, analysis of the conductive material (eg, purity of silver) can be performed according to the following procedure.

Six samples each having a length of 5 mm, a width of 5 mm and a thickness as the total thickness of the fixing rotating member were collected at an arbitrary position of the fixing rotating member. For each of the six samples obtained, a circumferential cross section of the fixing rotating member was exposed using a cross-section grinder (product name: SM09010, manufactured by JEOL Ltd.).

Subsequently, a cross section of each exposed conductive layer was observed using a scanning electron microscope (SEM) (product name: JSM-F100, manufactured by JEOL Ltd.), and the silver crystal particles in the observed image were analyzed by energy dispersive X-ray spectroscopy (EDS). The observation conditions included a 20,000-fold magnification and a secondary electron image acquisition mode, and EDS analysis conditions including an acceleration voltage of 5.0 kV and a working distance of 10 mm. The spatial range of the EDS analysis was region-specified and adjusted so that only the silver crystal particles in the observed image were selected.

Here, one image is acquired for one sample, and EDS analysis is performed at three locations in one image. By analyzing the purity of silver at a total of 18 locations in six samples and calculating the arithmetic mean of the results, the purity of silver constituting at least a portion of the conductive layer can be determined.

The maximum thickness of the conductive layer 20b is preferably 4 μm or less. By setting the maximum thickness of the conductive layer to 4 μm or less, the heat capacity of the conductive layer can be sufficiently reduced, and the time required to reach a temperature at which the conductive layer can be fixed by electromagnetic induction can be shortened. By setting the maximum thickness of the conductive layer to 4 μm or less, the bending resistance of the fixing rotating member can be further improved. As shown in FIG. 3 , the fixing rotating member 20 is driven to rotate while being pressed by the film guide 25 and the pressure roller 21. At each rotation, the fixing rotating member 20 is pressurized and deformed at the roller gap portion N, and is subjected to stress.

Due to the fact that the maximum thickness of the conductive layer is set to 4 μm or less, the conductive layer 20 b is less likely to suffer fatigue damage even when such repeated bending is applied to the fixing rotating member for a long period of time. This is because the thinner the conductive layer 20 b is, the smaller the internal stress acting on the conductive layer 20 b is when it is pressed and deformed to conform to the curved shape of the film guide 25.

The lower limit of the maximum thickness of the conductive layer 20b is not particularly limited, but is preferably 1 μm or more. Therefore, the maximum thickness of the conductive layer 20b is preferably 1 to 4 μm. In particular, the maximum thickness is 1 to 3 μm.

For example, the maximum thickness of the conductive layer in the fixing rotating member can be measured according to the following method.

Six samples each having a length of 5 mm, a width of 5 mm and a thickness as the total thickness of the fixing rotating member were collected at an arbitrary position of the fixing rotating member. For each of the six samples obtained, a circumferential cross section of the fixing rotating member was exposed using a cross-section grinder (product name: SM09010, manufactured by JEOL Ltd.).

Subsequently, a scanning electron microscope (SEM) (product name: JSM-F100, manufactured by JEOL Ltd.) was used to observe the cross section of the exposed conductive layer at an acceleration voltage of 3 kV, a working distance of 2.9 mm, and a magnification of 10,000 times to produce an image of 13 μm wide and 10 μm high. For the conductive layer in the obtained image, parallel lines were drawn at the portion closest to the substrate and at the portion closest to the resin layer on the opposite side; the distance between the drawn lines was regarded as the thickness in the image, and the maximum thickness was defined as the arithmetic mean of six samples. In the observation area, parallel lines were drawn with the surface on the opposite side of the conductive layer of the substrate as the reference.

The conductive layer 20b extends in the circumferential direction of the outer peripheral surface of the substrate 20a. As long as the conductive layer 20b can generate heat when energized, the conductive layer 20b can be configured according to a preferred pattern. In particular, a preferred configuration here is to form a plurality of conductive layers 20b each having an annular shape in the circumferential direction of the fixing rotating member, as shown in FIG. 4, while being electrically separated from each other in the direction of the rotation axis. By adopting such a configuration, a local increase in temperature when cracks occur in the conductive layer 20b can be reduced. The annular shape preferably has a substantially constant width in the axial direction of the rotating member.

In the case where the conductive layer is configured according to the pattern as described above, the surface area of the conductive layer 20b increases. When formed of copper, the conductive layer is more easily oxidized. In contrast, in the case where silver is used as the conductive layer material, the conductive layer can be prevented from being oxidized due to the increase in surface area caused by the patterning of the conductive layer as described above.

From the viewpoint of manufacturability and heat generation, the width of the loop of the conductive layer 20b is preferably 100 μm or more, more preferably 200 μm or more. In terms of heat generation non-uniformity and safety, the width of the loop of the conductive layer 20b is preferably 500 μm or less, more preferably 400 μm or less. The width of the loop is, for example, 100 to 500 μm, or 200 to 400 μm.

From the viewpoint of manufacturability and heat generation, the ring-to-ring spacing of the conductive layer 20b is preferably 50 μm or more, and more preferably 100 μm or more. In terms of heat generation non-uniformity, the ring-to-ring spacing in the conductive layer 20b is preferably 400 μm or less, and more preferably 300 μm or less. The ring-to-ring spacing is, for example, 50 to 300 μm, or 100 to 300 μm.

The conductive layer 20b has through holes in the thickness direction. Due to the presence of the through holes, the resin layer described below reaches the base material 20a by penetrating into the through holes. The base material 20a, the conductive layer 20b and the resin layer 20e are thus integrated and firmly bonded to each other, thereby improving durability while suppressing peeling.

The method of providing a hole that penetrates the conductive layer 20b in the thickness direction is not particularly limited. For example, the method may involve forming a pattern on the conductive layer 20b by photolithography, followed by forming holes by chemical etching, or forming holes by using a laser or a focused ion beam. In the present disclosure, hole formation by using a silver nanoparticle material will be particularly explained.

First, a film of a coating material containing silver nanoparticles having a particle size of 10 to 50 nm is formed. As a result, as shown in FIG8A , a state of particle stacking is produced. Even when fired at a low temperature of about 100° C., the instability of the surface energy of the nanoparticles causes the particles to fuse together, and as a result, a film having nano-sized pores is formed, as shown in FIG8B . The conductive layer 20 b is preferably a sintered body of silver nanoparticles.

The layered body of silver nanoparticles is formed by firing (sintering) at a high temperature of about 300° C. The firing temperature is preferably 280 to 450° C., or 300 to 400° C. During sintering, the nanoparticles further coalesce with each other, and the pores also coalesce with each other to minimize the surface energy, growing until the pores penetrate in the thickness direction, as shown in FIG8C .

The holes thus formed are believed to be connected not only in the thickness direction but also in the circumferential and axial directions and have a three-dimensional network structure. It is believed that the penetration of the resin layer 20e described below into the holes causes the contact area between the conductive layer 20b and the resin layer 20e to increase sharply and produce a more significant anchoring effect, which in turn translates into significantly improved adhesion.

(4) Resin layer

The fixing rotating member includes a resin layer 20e on the surface of the conductive layer 20b, which is opposite to the side of the conductive layer facing the substrate 20a. The resin layer 20e protects the conductive layer 20b and has the functions of preventing oxidation of the conductive layer 20b, ensuring insulation and improving strength.

The resin constituting at least a part of the resin layer 20e is not particularly limited. Similar to the resin used for the base material 20a, the resin in the resin layer 20e is preferably a resin whose physical properties change little when the conductive layer 20b is heated, and the resin can maintain high strength. Therefore, the resin layer 20e preferably includes a heat-resistant resin as a main component, and is preferably composed of a heat-resistant resin. The heat-resistant resin is, for example, a resin that does not melt or decompose at a temperature below 200°C (preferably below 250°C).

The resin constituting at least a portion of the resin layer 20e preferably includes at least one selected from the group consisting of polyimide (PI), polyamide-imide (PAI), modified polyimide and modified polyamide-imide. More preferably, the resin constituting at least a portion of the resin layer 20e is at least one selected from the group consisting of polyimide and polyamide-imide. The modification is the same as explained with respect to the substrate 20a.

These imide-based materials can be applied in the form of a liquid called a varnish; when applied to the conductive layer 20b, the material accordingly penetrates into the pores formed in the conductive layer 20b, so that the material can be subsequently made into a film by firing in this state. By using an imide-based material similar to the substrate 20a, the imide-based material penetrates into the pores of the conductive layer 20b, and once the material reaches the substrate 20a, adhesion can be further ensured, and the occurrence of peeling can be further suppressed.

Here, it is sufficient that the resin constituting at least a part of the resin layer 20e should penetrate into at least a part of the through hole. Preferably, the resin constituting at least a part of the resin layer 20e that has penetrated into the through hole is in contact with the substrate 20a. The degree of penetration is not particularly limited, and it is sufficient that the resin penetrates deeply enough so that peeling can be suppressed.

For example, in observation under a scanning electron microscope, the resin preferably penetrates into 50 to 100%, or 80 to 100%, or 90 to 100% of the through-holes (more preferably, the resin is in contact with the substrate 20a).

From the viewpoint of heat transfer, the resin layer 20e may contain a thermally conductive filler. Therefore, by improving heat transfer, the heat generated in the conductive layer 20b can be effectively transferred to the outer surface of the fixing rotating member.

The thickness of the resin layer 20e is preferably 10 to 100 μm, more preferably 20 to 60 μm. From the viewpoint of alleviating the stress acting on the conductive layer 20b when the fixing rotating member is bent, the thickness of the resin layer 20e and the thickness of the substrate 20a are appropriately adjusted according to the aforementioned materials. For example, specifically in the case where the substrate and the resin layer are made of the same material such as polyimide, it is preferred that the substrate and the resin layer have substantially the same thickness. That is, the ratio of the absolute value of the thickness difference between the substrate and the resin layer relative to the thickness of the substrate is preferably 10% or less, and particularly 5% or less. In the case where the substrate is composed of polyimide and the resin layer is composed of polyamide-imide, the thickness of the resin layer is preferably in the range of, for example, 15% to 25%. By setting the thickness relationship between the substrate and the resin layer as described above, it is easier to prevent cracks from occurring in the conductive layer 20b when the fixing rotating member is bent.

The materials of the base material 20 a and the resin layer 20 e of the fixing rotating member can be analyzed according to the following procedure.

A 10 mm square sample is cut out from the fixing rotating member, and any elastic layer or surface layer of the sample is removed using a razor or a solvent. The material can be checked by performing total reflection (ATR) measurement on the obtained sample using an infrared spectrometer (FT-IR) (e.g., product name: Frontier FT-IR, manufactured by PerkinElmer Inc.).

(5) Elastic layer

The fixing rotating member may have an elastic layer 20c on the outer surface of the resin layer 20e. The elastic layer 20c is a layer for imparting flexibility to the fixing rotating member in order to ensure a fixing nip in the fixing device. In the case where the fixing rotating member is used as a heating member that contacts the toner on the paper, the elastic layer 20c also functions as a layer imparting flexibility so that the surface of the heating member can follow the unevenness of the paper.

The elastic layer 20c has, for example, rubber as a matrix and particles dispersed in the rubber. More specifically, the elastic layer 20c preferably contains rubber and a thermally conductive filler, and is preferably composed of a cured product obtained by curing a composition containing at least a rubber starting material (base polymer, crosslinking agent, etc.) and a thermally conductive filler.

From the viewpoint of exerting the function of the elastic layer 20 c described above, the elastic layer 20 c is preferably made of a cured silicone rubber containing thermally conductive particles, and more preferably made of a cured product of an addition-curable silicone rubber composition.

The silicone rubber composition may include, for example, thermally conductive particles, a base polymer, a crosslinking agent, and a catalyst, and may further include additives as required. Most silicone rubber compositions are liquid, so thermally conductive fillers are easily dispersed; depending on the type and amount of thermally conductive fillers added, the elasticity of the elastic layer 20c to be produced can be easily adjusted by adjusting the degree of crosslinking.

The matrix has a function of exerting elasticity in the elastic layer 20c. From the viewpoint of exerting the above-mentioned function of the elastic layer 20c, the matrix preferably contains silicone rubber. Silicone rubber is preferred here because it exhibits high heat resistance, so that flexibility can be maintained even in an environment where a high temperature of about 240°C is reached in the non-paper feeding portion. For example, a cured product of the following addition-curable liquid silicone rubber composition can be used as the silicone rubber. The elastic layer 20c can be formed by applying and heating the liquid silicone rubber composition according to a known method.

The liquid silicone rubber composition generally comprises 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; and

Component (d): Thermally conductive filler

The various components will be explained below.

Component (a)

The organopolysiloxane having an unsaturated aliphatic group is an organopolysiloxane having an unsaturated aliphatic group such as a vinyl group; examples thereof include those represented by the following formula (1) and formula (2).

In formula (1), ^m1 represents an integer equal to or greater than 0, and ⁿ¹ represents an integer equal to or greater than 3. In formula (1), ^R1 each independently represents a monovalent unsubstituted or substituted hydrocarbon group containing no unsaturated aliphatic group, wherein at least one of ^R1 represents a methyl group; and ^R2 each independently represents an unsaturated aliphatic group.

In formula (2), ⁿ² represents a positive integer, ^R3 each independently represents a monovalent unsubstituted or substituted hydrocarbon group containing no unsaturated aliphatic group, wherein at least one ^R3 represents a methyl group, and ^R4 each independently represents an unsaturated aliphatic group.

In formulae (1) and (2), examples of the monovalent unsubstituted or substituted hydrocarbon group containing no unsaturated aliphatic group which can be represented by ^R1 and ^R3 include the following groups.

-Unsubstituted hydrocarbon

Alkyl (eg, methyl, ethyl, propyl, butyl, pentyl, and hexyl).

Aryl (eg, phenyl).

-Substituted hydrocarbon

Substituted alkyl (eg, chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, 3-cyanopropyl, and 3-methoxypropyl).

The organopolysiloxane represented by formulae (1) and (2) has at least one methyl group directly bonded to a silicon atom forming a chain structure. However, for reasons of ease of synthesis and handling, preferably more than 50% of each of ^R1 and ^R3 are methyl groups, and more preferably all of ^R1 and ^R3 are methyl groups.

Examples of unsaturated aliphatic groups that can be represented by R and R in formulas (1) and (2) include the following groups. Examples of unsaturated aliphatic groups include vinyl groups, ^allyl groups, 3-butenyl groups, ⁴ -pentenyl groups, and 5-hexenyl groups. In the foregoing, all of ^R and R are ^preferably vinyl groups because they are easy to synthesize and handle, are inexpensive, and are easy to undergo crosslinking reactions.

From the viewpoint of formability, the viscosity of component (a) is preferably 1000 mm ² /s to 50000 mm ² /s. When the viscosity is lower than 1000 mm ² /s, it is difficult to adjust the hardness to the hardness required for the elastic layer 20c, and when the viscosity is higher than 50000 mm ² /s, the viscosity of the composition becomes too high, which makes coating difficult. Based on JIS Z 8803:2011, the viscosity (dynamic viscosity) can be measured herein using, for example, a capillary viscometer or a rotational viscometer.

The compounding amount of the component (a) is preferably 55 vol% or more from the viewpoint of durability and is preferably 65 vol% or less from the viewpoint of heat transfer, based on the liquid silicone rubber composition for forming the elastic layer 20 c .

Component (b)

The organopolysiloxane having active hydrogen bonded to silicon is used herein as a crosslinking agent which reacts with the unsaturated aliphatic groups of component (a) under catalysis to form a cured silicone rubber.

Any organopolysiloxane having Si-H bonds can be used as component (b). In particular, from the viewpoint of reactivity with the unsaturated aliphatic group of component (a), an organopolysiloxane having 3 or more as the average number of hydrogen atoms bonded to silicon in one molecule is preferably used.

Specific examples of component (b) include linear organopolysiloxanes represented by the following formula (3) and cyclic organopolysiloxanes represented by the following formula (4).

In formula (3), ^m2 represents an integer equal to or greater than 0, ⁿ³ represents an integer equal to or greater than 3, and ^R5 each independently represents a monovalent unsubstituted or substituted hydrocarbon group containing no unsaturated aliphatic group.

In formula (4), ^m3 represents an integer equal to or greater than 0, ⁿ⁴ represents an integer equal to or greater than 3, and ^R6 each independently represents a monovalent unsubstituted or substituted hydrocarbon group containing no unsaturated aliphatic group.

Examples of the monovalent unsubstituted or substituted hydrocarbon group containing no unsaturated aliphatic group which may be represented by R ⁵ and R ⁶ in formulae (3) and (4) include, for example, groups similar to R ¹ in the above structural formula (1). However, for reasons of ease of synthesis and handling, in the above, it is preferred that 50% or more of each of R ⁵ and R ⁶ is methyl, and it is more preferred that all of R ⁵ and R ⁶ are methyl, because in this case excellent heat resistance can be easily obtained.

Component (c)

The catalyst used to form the silicone rubber includes, for example, a hydrosilylation catalyst for accelerating the curing reaction. Known substances such as platinum compounds and rhodium compounds can be used as hydrosilylation catalysts. The compounding amount of the catalyst can be appropriately set and is not particularly limited.

Component (d)

Examples of thermally conductive fillers include metals, metal compounds, and carbon fibers. Highly thermally conductive fillers are more preferred; specific examples thereof include the following materials.

Metal silicon (Si), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), boron nitride (BN), aluminum nitride (AlN), aluminum oxide (Al ₂ O ₃ ), zinc oxide (ZnO), magnesium oxide (MgO), silicon dioxide (SiO ₂ ), copper (Cu), aluminum (Al), silver (Ag), iron (Fe), nickel (Ni), vapor grown carbon fiber, PAN-based (polyacrylonitrile) carbon fiber and pitch-based carbon fiber.

These fillers may be used alone or in combination of two or more.

From the viewpoint of handling and dispersibility, the average particle size of the filler is preferably 1 μm to 50 μm. The shape of the filler may be spherical, powdery, needle-like, flake-like or whisker-like. In particular, from the viewpoint of dispersibility, the filler is preferably spherical. At least one of a reinforcing filler, a heat-resistant filler and a coloring filler may be further added.

(6) Adhesive layer

The fixing rotating member may have an adhesive layer 20f for bonding the surface layer 20d described below on the outer surface of the elastic layer 20c. The adhesive layer 20f is a layer for bonding the elastic layer 20c and the surface layer 20d. The adhesive used in the adhesive layer 20f can be appropriately selected and used from known adhesives, and is not particularly limited. However, from the viewpoint of easy handling, it is preferable to use an addition-curable silicone rubber in which a self-adhesive component is formulated.

The adhesive may contain, for example, a self-adhesive component, an organopolysiloxane having a plurality of unsaturated aliphatic groups represented by a vinyl group in a molecular chain, a hydrogen organopolysiloxane, and a platinum compound as a crosslinking catalyst. As a result of the addition reaction, an adhesive layer 20f that bonds the surface layer 20d to the elastic layer 20c may be formed by curing the adhesive applied to the surface of the elastic layer 20c.

Examples of the above-mentioned self-adhesive components include the following.

- Silane having at least one type, and preferably two or more types, selected from alkenyl groups such as vinyl groups, (meth)acryloyloxy groups, hydrosilyl groups (SiH groups), epoxy groups, alkoxysilyl groups, carbonyl groups and phenyl groups.

- Organosilicon compounds, for example cyclic or linear siloxanes having 2 to 30 silicon atoms and preferably 4 to 20 silicon atoms.

- Non-silicon organic compounds (i.e., no silicon atom in the molecule), optionally containing oxygen atoms in the molecule. The organic compound contains 1 to 4, preferably 1 or 2 aromatic rings in one molecule, such as a phenylene structure, with 1 to 4 valences, preferably 2 to 4 valences.

The organic compound also contains at least one functional group (eg, an alkenyl group or a (meth)acryloyloxy group) in one molecule, preferably 2 to 4 such functional groups, which are capable of facilitating a hydrosilylation addition reaction.

The above self-adhesive components may be used alone or in combination of two or more types. From the viewpoint of adjusting viscosity and ensuring heat resistance, a filler component may be added to the adhesive within the scope consistent with the gist of the present disclosure. Examples of the filler component include the following.

-Silicon dioxide, aluminum oxide, iron oxide, cerium oxide, cerium hydroxide, and carbon black, etc.

The compounding amount of various components contained in the adhesive is not particularly limited and can be appropriately set. Such addition-curable silicone rubber adhesive is commercially available and can be easily obtained. The thickness of the adhesive layer 20f is preferably 20 μm or less. By stipulating that the thickness of the adhesive layer 20f is 20 μm or less, when the fixing belt according to the present embodiment is used as a heating belt in a heat fixing device, the thermal resistance can be easily set to be small, and the heat from the inner surface side can be easily transferred to the recording medium with good efficiency.

(7) Surface layer

The fixing rotating member may have a surface layer 20d. The surface layer 20d preferably contains a fluorine resin, and its purpose is to function as a release layer that prevents toner from adhering to the outer surface of the fixing rotating member. The surface layer 20d can be formed, for example, by tubular molding of a resin exemplified below, or by molding the surface layer 20d by applying a resin dispersion.

- tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (PFA), polytetrafluoroethylene (PTFE), and tetrafluoroethylene-hexafluoropropylene copolymer (FEP), etc.

Among these exemplary resin materials, PFA is particularly preferably used from the viewpoints of moldability and toner releasability.

The thickness of the surface layer 20d is preferably 10 μm to 50 μm. By stipulating the thickness of the surface layer 20d to be within this range, appropriate surface hardness of the fixing rotating member is easily maintained.

As described above, one aspect of the present disclosure provides a fixing device in which a fixing rotating member is provided. Therefore, a fixing device in which a fixing rotating member having high conductivity and excellent durability is provided can be provided.

At least one aspect of the present disclosure allows for a fixing rotating member having excellent durability, and the fixing rotating member includes a conductive layer containing silver so that the conductive layer exhibits high adhesion to a substrate. At least one aspect of the present disclosure also allows for a fixing device that helps to stably provide high-quality electrophotographic images. At least one aspect of the present disclosure also allows for an electrophotographic image forming device that can form stable high-quality electrophotographic images.

Example

The present disclosure will be explained in more detail below based on Examples, but the present disclosure is not intended to be limited to these Examples.

[Example 1]

The surface of a cylindrical stainless steel mold having an outer diameter of 30 mm was subjected to demolding treatment, and a commercially available polyimide precursor solution (Uvarnish S of Ube Co.) was applied to the surface according to a dipping method to form a coating film. The coating film was then 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 at 400°C for 30 minutes to initiate imidization, and a polyimide coating film having a thickness of 40 μm and a length of 300 mm was formed.

Then, a ring pattern with a width of 300 μm and a pitch of 200 μm was formed on the polyimide film by inkjetting using an ink containing silver nanoparticles (DNS163, manufactured by Daicel Corporation) Thereafter, firing was performed at 300° C. for 30 minutes to form a conductive layer 20 b with a maximum thickness of 2 μm.

Next, a PAI solution (Vylomax HR-16NN, manufactured by Toyobo Co., Ltd.) was applied to the entire surface of the conductive layer 20b by ring coating and then fired at 200°C for 30 minutes to form a resin layer 20e having a thickness of 40 μm.

Then, a primer (product name: DY39-051A/B, manufactured by Dow Toray Industries, Inc.) was substantially uniformly applied to the outer peripheral surface of the resin layer 20e in an amount of 20 mg by dry weight, and after the solvent dried, a baking treatment was performed in an electric furnace set at 160°C for 30 minutes.

A silicone rubber composition layer having a thickness of 250 μm was then formed on the primer by ring coating; the layer was primary crosslinked at 160° C. for 1 minute and then secondary crosslinked at 200° C. for 30 minutes to form an elastic layer 20 c .

The following silicone rubber compositions were used.

As component (a), i.e., an organopolysiloxane having an alkenyl group, a vinylated polydimethylsiloxane having at least two vinyl groups in one molecule (product name: DMS-V41, manufactured by Gelest Inc., number average molecular weight 68,000 (polystyrene basis); molar equivalent of vinyl group: 0.04 mmol/g) was prepared.

As component (b), i.e., an organopolysiloxane having Si-H groups, polymethylhydrogensiloxane (product name: HMS-301, manufactured by Gelest Inc., number average molecular weight 1300 (polystyrene basis), molar equivalent of Si-H groups: 3.60 mmol/g) having at least two Si-H groups in one molecule was prepared. Then, 0.5 parts by mass of component (b) was added to 100 parts by mass of component (a), and the mixture was mixed thoroughly to obtain an addition-curable silicone rubber stock solution.

As the catalyst component (c), a very small amount of a catalyst for addition curing reaction (platinum catalyst: platinum carbonylcyclovinylmethylsiloxane complex) and an inhibitor are added and mixed thoroughly.

To this addition-curable silicone rubber stock solution, component (d), a thermally conductive filler in the form of high-purity true spherical alumina (product name: Alunabeads CB-A10S; manufactured by Showa Titanium Co.), was added, blended and kneaded at a volume ratio of 45% based on the elastic layer, thereby obtaining an addition-curable silicone rubber composition having a durometer hardness of 10° in accordance with JIS K 6253A after curing.

Subsequently, an addition curable silicone rubber adhesive (product name: SE1819CV A/B, manufactured by Dow Toray Co., Ltd.) for forming an adhesive layer 20f was substantially uniformly applied to the obtained elastic layer 20c to a thickness of about 20 μm. A fluororesin tube (product name: NSE, manufactured by Gunze Ltd.) having an inner diameter of 29 mm and a thickness of 50 μm for forming a surface layer 20d was further placed on the elastic layer 20c while the diameter of the tube was expanded.

Thereafter, the excess adhesive was removed from between the elastic layer 20c and the fluororesin tube by evenly wiping the belt surface from above the fluororesin tube so as to leave a small span of about 5 μm. The adhesive was then cured by heating at 200°C for 30 minutes to fix the fluororesin tube to the elastic layer 20c; finally, both ends were cut off so as to have a length of 240 mm, and a fixing rotary member was produced.

[Example 2]

A fixing rotating member was produced in the same manner as in Example 1 except that the firing temperature of the conductive layer 20b was set to 350°C.

[Example 3]

A fixing rotating member was produced in the same manner as in Example 1 except that the firing temperature of the conductive layer 20b was set to 400°C.

[Example 4]

A fixing rotating member was produced in the same manner as in Example 1, except that the material of the resin layer 20e here was a polyimide precursor solution (Uvarnish S, produced by UBE), dried at 140°C for 30 minutes, and fired at 200°C for 30 minutes and at 400°C for 30 minutes to induce imidization and layer formation.

[Example 5]

A fixing rotating member was produced in the same manner as in Example 4 except that the firing temperature of the conductive layer 20b was set to 350°C.

[Example 6]

A fixing rotating member was produced in the same manner as in Example 4 except that the firing temperature of the conductive layer 20b was set to 400°C.

[Comparative Example 1]

A fixing rotating member was produced in the same manner as in Example 1 except that the firing temperature of the conductive layer 20b was set to 150°C.

[Comparative Example 2]

A fixing rotating member was produced in the same manner as in Example 4 except that the firing temperature of the conductive layer 20b was set to 150°C.

Evaluation: Cross-section observation

The cross section of the conductive layer 20 b of each of Examples 1 to 6 and Comparative Examples 1 and 2 was observed to confirm the presence or absence of a hole penetrating in the thickness direction.

Samples having a length of 5 mm, a width of 5 mm, and a thickness equal to the total thickness of the fixing rotating member were taken from any six positions of the fixing rotating member. Each of the six samples obtained was ground using an ion milling device (product name: IM4000, manufactured by Hitachi High-Technologies Corporation) to expose a cross section in the total thickness direction of the conductive layer. Here, the cross section was ground by ion milling so that particles were prevented from falling off the sample and contamination by abrasives was prevented, and a cross section showing very few grinding marks could be formed.

Then, for each sample, a Schottky field emission scanning electron microscope (SEM) (product name: FE-SEM JSM-F100, produced by JEOL Ltd.) equipped with an energy dispersive X-ray spectrometer (EDS) was used to observe the exposed cross section in the ground cross section of each sample to obtain a cross-sectional image. As an observation condition, a backscattered electron image mode with a magnification of 20,000 times was used, and as a backscattered electron image acquisition condition, the acceleration voltage was set to 3.0 kV and the working distance was set to 3 mm. From the cross-sectional image thus obtained, it was determined whether the conductive layer 20b had a hole that penetrated in the thickness direction, that is, a through hole. When at least one through hole was confirmed in any cross-sectional image of the conductive layer, it was determined that the observed fixing rotating member was a fixing rotating member according to the present disclosure.

In addition, based on the cross-sectional image, it is checked whether the resin constituting at least a part of the resin layer 20e has penetrated into at least a part of the through hole. Here, one of the cross-sectional images of the fixing rotating member according to Embodiment 4 is shown in FIG9. From FIG9, it is determined that the conductive layer of the fixing rotating member of Embodiment 4 has the through hole, and it is determined that the resin constituting at least a part of the resin layer 20e has penetrated into the through hole.

In addition, elemental analysis was performed on the cross section of the conductive layer in the thickness direction of the conductive layer, which was exposed on the ground surface of the sample. Elemental analysis was performed using EDS installed on JSM-F100 under the conditions of an accelerating voltage of 5 to 15 kV and a magnification of 4000 times. In addition, elemental analysis was performed on any three positions of the cross section of the conductive layer. Therefore, elemental analysis was performed at a total of 18 positions, i.e., 3 positions × 6 samples. Then, the arithmetic mean of the purity of silver obtained at 18 positions (i.e., 3 positions × 6 samples) was taken as the purity of silver in the conductive layer of the observed fixing rotating member.

(Evaluation: Durability test)

For Examples 1 to 6 and Comparative Examples 1 and 2, a repeated bending durability test (MIT folding durability tester, produced by Toyo Seiki Seisaku-sho, Ltd.) was performed, and peeling after the durability test was observed. The test temperature was 200°C, the bending angle was 135°, and the bending curvature was 6 mm, and the number of bendings was 2,000,000 times. The test results were evaluated according to the following criteria.

Grade A: No peeling of the resin layer and the conductive layer occurs;

Rank B: Peeling of the resin layer and the conductive layer occurred before the number of bending reached 2,000,000 times.

The results are shown in Table 1. Here, in Table 1, for Comparative Examples 1 and 2, the number of bending times when the resin layer and the conductive layer were peeled off was observed for the first time.

[Table 1]

When the conductive layer has a through hole in the thickness direction, the item “through hole” is marked as “yes”. When the resin constituting at least a part of the resin layer penetrates into at least a part of the through hole, the item “resin penetrates into the hole” is marked as “yes”.

FIG9 reveals that, in Example 4, there are through holes in the thickness direction of the conductive layer 20b, and the resin layer 20e penetrates into the holes, reaches the substrate 20a and contacts the substrate. No interface or the like is seen between the substrate 20a and the resin layer 20e, so it is found that they are combined with each other and become one. In other embodiments, the resin layer is also in contact with the substrate similarly.

In comparison between Examples and Comparative Examples, the results in Table 1 show that in those cases where conductive layer 20b had holes penetrating in the thickness direction and the resin of the resin layer penetrated into the holes, no peeling was observed and good durability was demonstrated.

Although the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the present disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims (9)

1. A fixing rotating member, characterized in that it comprises: a substrate comprising a resin; A conductive layer on the substrate; and a resin layer on a surface of the conductive layer, the surface being opposite to a side of the conductive layer facing the substrate, The conductive layer extends along the circumferential direction of the outer peripheral surface of the substrate. The conductive layer comprises silver, The conductive layer has through holes in the thickness direction thereof; Here, at least a portion of the through hole is infiltrated by the resin constituting at least a portion of the resin layer. 2 . The fixing rotating member according to claim 1 , wherein the resin constituting at least a part of the resin layer includes at least one selected from the group consisting of polyimide and polyamide-imide. 3 . The fixing rotating member according to claim 2 , wherein the resin contained in the base material contains at least one selected from the group consisting of polyimide and polyamide-imide. 4 . The fixing rotating member according to claim 1 , wherein a maximum thickness of the conductive layer is 4 μm or less. 5 . The fixing rotating member according to claim 1 , wherein the resin constituting the resin layer and penetrating the through-holes is in contact with the base material. 6 . The fixing rotating member according to claim 1 , wherein the conductive layer is a sintered body of silver nanoparticles. 7. A fixing device, comprising the fixing rotating member according to any one of claims 1 to 6, and an induction heating device for heating the fixing rotating member by induction heating. 8. The fixing device according to claim 7, wherein the induction heating device has an exciting coil for forming an alternating magnetic field for causing the conductive layer to generate heat by electromagnetic induction, the exciting coil being disposed inside the fixing rotating member and having a spiral shape with a spiral axis substantially parallel to the direction of the rotation axis of the fixing rotating member; and a magnetic core which is provided in the spiral-shaped portion and does not form a loop outside the fixing rotating member, extends in the rotation axis direction, and is used to guide magnetic lines of force of the alternating magnetic field; and The material of the magnetic core is ferromagnetic, and The conductive layer generates heat mainly through the induced current induced by the magnetic lines of force. The magnetic lines of force are emitted from one lengthwise end of the magnetic core, pass through the outside of the conductive layer, and return to the other lengthwise end of the magnetic core. 9. An electrophotographic image forming device, characterized in that it comprises: an image bearing member that bears 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, wherein the fixing device is the fixing device according to claim 7.