JP2011017988A - Endless belt, method for manufacturing the same, fixing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endless belt that prevents a resin layer from being separated from a metal layer.SOLUTION: The endless belt 10 includes: the annular resin layer 10A having a plurality of protrusions 20 that are formed along the circumferential direction on the outer peripheral surface so that the tip 20A of each of the protrusions faces toward one side in the circumferential direction; and the metal layer 10B formed on the outer peripheral surface of the resin layer. In driving and rotating the endless belt as a fixing belt for a fixing device employing an electromagnetic induction heating system, the belt is rotated in the same circumferential direction faced by the tip of each of the protrusions formed on the resin layer.

Description

  The present invention relates to an endless belt, a manufacturing method thereof, a fixing device, and an image forming apparatus.

In recent years, methods for heating a fixing member by induction heating have been proposed (see Patent Documents 1 and 2).
The electromagnetic induction heating and fixing method requires a coil and a high-frequency power source in addition to a heating and fixing member having a heat generating layer and a pressure member. The coil is installed inside the heat fixing member or at a position close to the external heat fixing member, and is electrically connected to a high frequency power source. A high-frequency alternating current is passed through the coil by the high-frequency power source. A magnetic flux is generated in the coil in a direction orthogonal to the surface around which the coil is wound in accordance with the direction of current. The magnetic flux crosses the heat generating layer of the heat fixing member installed close to the coil, and an eddy current that generates a magnetic field is generated in the heat generating layer of the heat fixing member in the direction to cancel the magnetic flux. Since the heat generating layer has a resistance value determined by its material and thickness, the electric energy generated by the eddy current is converted into heat energy. The electromagnetic induction heating type fixing device (electromagnetic induction heating fixing device) fixes the image on the recording medium using the heat generated in this way.

In the electromagnetic induction heating fixing device, the surface of the member to be heated is heated effectively and with high thermal efficiency. Therefore, by using a fixing belt having a small heat capacity as a heating fixing member, the fixing start time is greatly increased. Shortened.
Among electromagnetic induction heating and fixing devices, in a fixing device composed of a fixing belt and a pressure roll, the fixing belt is configured to rotate (follow) in the reverse direction as the pressure roll rotates. It is common.

  On the other hand, gear members are attached to both ends of the fixing belt for the purpose of avoiding the effects of thermal expansion of the pressure roll and slippage between the fixing belt and the pressure roll. Techniques have been proposed in which the fixing belt is directly driven by coupling (see Patent Documents 3 to 5).

JP 11-352804 A JP 2000-188177 A JP 2005-249958 A JP 2006-47768 A JP 2006-227106 A

  An object of the present invention is to provide an endless belt in which a resin layer and a metal layer are less likely to be peeled than an endless belt in which the outer peripheral surface of a resin layer is simply roughened.

The invention according to claim 1 has a plurality of protrusions along at least the circumferential direction of the outer peripheral surface, and the plurality of protrusions are arranged such that respective tips of the plurality of protrusions face one side in the circumferential direction. An endless belt having an annular resin layer formed and a metal layer formed on the outer peripheral surface of the resin layer.
The invention according to claim 2 is the endless belt according to claim 1, wherein the fixing belt rotates in a circumferential direction on the side of each of the plurality of projecting portions of the resin layer, and the fixing belt. Heating means for heating the metal layer by electromagnetic induction, pressurizing a part of the outer peripheral surface of the fixing belt, and rotating the fixing belt in the circumferential direction on the side where the tips of the plurality of protrusions face. And a pressure member that rotates in a direction opposite to the circumferential direction.
According to a third aspect of the present invention, there is provided a fixing belt as the endless belt according to the first aspect, heating means for generating heat by electromagnetic induction of a metal layer of the fixing belt, and pressurizing a part of the outer peripheral surface of the fixing belt. And a pressure member that rotates the fixing belt in a direction opposite to a circumferential direction on a side to which tips of the plurality of protruding portions of the resin layer face.
According to a fourth aspect of the present invention, there is provided an image carrier, a charging unit for charging the surface of the image carrier, and electrostatic latent image formation for forming an electrostatic latent image on the surface of the image carrier charged by the charging unit. Developing means for developing the electrostatic latent image with toner to form a toner image; transfer means for transferring the toner image to a recording medium; and transferring the toner image transferred to the recording medium to the recording medium An image forming apparatus comprising: a fixing unit that fixes the toner image to the fixing device according to claim 2.
The invention of claim 5 provides an annular resin layer, rotates the resin layer in the circumferential direction, and the region where the abrasive grains are applied to the outer peripheral surface of the resin layer is viewed from the direction in which the abrasive grains are applied. By applying the abrasive grains to the outer peripheral surface of the resin layer so as not to overlap with the position of the central axis for rotating the resin layer, the resin is arranged such that a plurality of protrusions are directed to one side in the circumferential direction. It is a manufacturing method of an endless belt including a step of forming along at least the circumferential direction of the outer peripheral surface of the layer and a step of forming a metal layer on the outer peripheral surface of the resin layer.
In the invention of claim 6, the region where the abrasive grains are applied to the outer peripheral surface of the resin layer is upstream of the position of the central axis that rotates the resin layer when viewed from the direction of applying the abrasive grains. It is a manufacturing method of the endless belt of Claim 5 which hits the said abrasive grain to the outer peripheral surface of a resin layer.

According to the invention which concerns on Claim 1, compared with the endless belt with which the outer peripheral surface of the resin layer is simply roughened, the endless belt with which peeling between a resin layer and a metal layer is suppressed is provided.
According to the second aspect of the present invention, as compared with the electromagnetic induction heating type fixing device provided with the fixing belt in which the outer peripheral surface of the resin layer is simply roughened, it is between the resin layer and the metal layer of the fixing belt. There is provided an electromagnetic induction heating type fixing device in which peeling of the toner is suppressed.
According to the third aspect of the present invention, compared to the electromagnetic induction heating type fixing device provided with the fixing belt in which the outer peripheral surface of the resin layer is simply roughened, it is between the resin layer and the metal layer of the fixing belt. There is provided an electromagnetic induction heating type fixing device in which peeling of the toner is suppressed.
According to the invention of claim 4, in the image forming apparatus provided with the electromagnetic induction heating type fixing device that drives and rotates the pressure member, the fixing belt in which the outer peripheral surface of the resin layer is simply roughened is provided. An image forming apparatus is provided in which peeling between the resin layer and the metal layer of the fixing belt is suppressed as compared with the case where the fixing belt is provided.
According to the invention which concerns on Claim 5, compared with the endless belt in which the outer peripheral surface of the resin layer is simply roughened, the endless belt from which the endless belt in which the separation between the resin layer and the metal layer is suppressed is obtained. A manufacturing method is provided.
According to the invention which concerns on Claim 6, the endless belt by which peeling between a resin layer and a metal layer is suppressed can be obtained more reliably compared with the endless belt whose outer peripheral surface of the resin layer is simply roughened. A method of manufacturing an endless belt is provided.

It is the schematic which shows the cross section of the circumferential direction of the endless belt which concerns on this embodiment. 1 is a schematic diagram illustrating a configuration of a fixing device according to an exemplary embodiment. It is the schematic which shows a part of circumferential cross section of the resin layer of the endless belt which concerns on this embodiment. It is the schematic which shows a part of outer peripheral surface of the resin layer of the endless belt which concerns on this embodiment. It is the schematic which shows an example of the method of roughening in the state where the outer peripheral surface of the resin layer which comprises the fixing belt which concerns on this embodiment was rolled up. It is the schematic which shows a part of resin layer roughened in the state where the outer peripheral surface rolled up. 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment. It is the schematic which shows the method of roughening the outer peripheral surface of a resin layer in the comparative example 1. It is the schematic which shows a part of resin layer of the endless belt concerning other embodiment.

Hereinafter, embodiments will be described with reference to the drawings.
Generally, the fixing belt has low rigidity, and a resin layer having low adhesion due to sliding resistance between the fixing belt and a supporting member (pressing member) that supports the fixing belt, repeated distortion in the contact region, or the like. There is a concern that peeling occurs between the metal layer and a crack occurs in the metal layer and the metal layer is not heated and buckling due to a decrease in rigidity.
The endless belt according to the present embodiment has a configuration in which such peeling between the resin layer and the metal layer is effectively suppressed.

<Endless belt>
FIG. 1 schematically shows a cross-sectional configuration in the circumferential direction of an endless belt according to the present embodiment, and FIG. 2 shows an electromagnetic induction heating type fixing device including the endless belt according to the present embodiment as a fixing belt. Electromagnetic induction heating fixing device "and" fixing device ") are schematically shown.
An endless belt 10 (referred to as “fixing belt” or “belt” as appropriate) according to the present embodiment includes a resin layer (resin substrate layer) 10A serving as a substrate from the inner peripheral surface side toward the outer peripheral surface side. A base metal layer (metal anchor layer) 10B, a metal heating layer 10C, a metal protective layer 10D, an elastic layer 10E, and a release layer 10F are laminated in this order. Hereinafter, each component will be described.

[Resin layer]
The resin layer 10 </ b> A serving as the base material of the fixing belt 10 generates heat from the adjacent metal heating layer 10 </ b> C, and is repeatedly conveyed (rotated) in the circumferential direction of the belt 10 at the fixing temperature in the electromagnetic induction heating fixing device 100. However, it is desirable that the resin layer is a resin layer that maintains high strength and that is mainly composed of a heat-resistant resin (in this specification, “mainly” and “main component” are expressed in terms of mass ratio). It means 50% or more.)

  In the case of the resin layer 10 </ b> A mainly composed of a heat resistant resin, slidability with the pressing member 13 in contact with the inner peripheral surface of the fixing belt 10 is ensured, and the life of the pressing member 13 is extended. Furthermore, since the heat resistant resin has a heat insulating effect, the heat generated in the metal heat generating layer 10 </ b> C is efficiently used without letting it escape to the pressing member 13.

Examples of the heat-resistant resin constituting the resin layer 10A include high heat-resistant and high-strength resins, such as liquid crystal materials such as polyimide, aromatic polyamide, and thermotropic liquid crystal polymer. Examples include terephthalate, polyethersulfone, polyetherketone, polysulfone, and polyimideamide. Among these, polyimide is desirable.
Moreover, you may further improve a heat insulation effect by adding the filler with a heat insulation effect in a heat resistant resin, or making a heat resistant resin foam.

The thickness of the resin layer 10 </ b> A is preferably in the range of 10 μm or more and 200 μm or less from the viewpoint of achieving both rigidity and flexibility for realizing long-term repeated conveyance (rotation) of the fixing belt 10. If the thickness of the resin layer is 10 μm or more, the rigidity is relatively strong, and it is possible to effectively suppress wrinkles and cracks at the edges during rotation. On the other hand, if the thickness of the resin layer is 200 μm or less, flexibility is easily secured, an increase in heat capacity is suppressed, and a warm-up time is shortened.
The thickness of the resin layer 10A is a value measured by an eddy current film thickness meter (manufactured by Fisher Instruments Co., Ltd.).

  As shown in FIG. 3 and FIG. 4, a large number of minute protrusions 20 such as scissors are formed on the outer peripheral surface of the resin layer 10 </ b> A, and the tip 20 </ b> A of each protrusion 20 is one of the circumferential directions (arrow B). Direction). Thus, in the outer peripheral surface of the resin layer 10A, the metal layer formed on the resin layer 10A is formed by the numerous protrusions 20 formed over the entire outer peripheral surface so that the tip 20A faces the same circumferential side. 10B, 10C, and 10D, at least the base metal layer 10B, and in some cases, the heat generating layer 10C and further the protective layer 10D has a laminated structure in which the protruding portion 20 bites into the resin layer 10A and the metal layer 10B. High adhesion is ensured between the two.

  Each protrusion 20 formed on the outer peripheral surface of the resin layer 10A has a distal end (as shown in FIG. 3) of the protrusion 20 when viewed in a circumferential cross section passing through the distal end 20A of the protrusion 20. (Vertex) When the inclination angle of the line connecting 20A and the root 20B on the side where the tip of the protrusion 20 faces is θ1, and the inclination angle of the line connecting the tip 20A of the protrusion 20 and the root 20C on the other side is θ2. , Θ1> θ2. For example, θ1 is in the range of 70 ° or more and 150 ° or less, θ2 is in the range of 30 ° or more and 80 ° or less, and the relationship θ1> θ2 is satisfied, so that the relationship between the resin layer 10A and the metal layer 10B is satisfied. Higher adhesion is ensured.

As described above, the method of forming the protruding portion 20 on the outer peripheral surface of the resin layer 10A so that the tip 20A is directed to one side in the circumferential direction is not particularly limited. For example, an abrasive is applied to a specific region on the surface of the resin layer 10A. A method of roughening by applying grains can be mentioned. As a method for applying the abrasive grains, dry blasting and wet blasting are preferable. Wet blasting, also called liquid honing, is a method in which abrasive grains are blown together with water having a water pressure of about 0.2 MPa to 5.0 MPa to roughen the surface, and there is little influence on the working environment due to scattering of abrasive grains. There is an advantage that the discharge nozzle is not easily clogged.
As the abrasive grains, although depending on the material of the resin layer 10A, for example, abrasive grains such as alumina and silicon carbide having a particle diameter of about 10 μm to 100 μm are used.

  For example, a resin layer is formed around a cylindrical support by a known coating method, the resin layer is rotated in the circumferential direction, and the position of the central axis that rotates the resin layer 10A when viewed from the direction of applying the abrasive grains; Apply abrasive grains to areas that do not overlap. More specifically, as shown in FIG. 5, there is a region where the abrasive grains 32 are applied to the outer peripheral surface of the resin layer 10 </ b> A when viewed from the direction (arrow P direction) where the abrasive grains 32 are applied from the discharge nozzle 30 of the liquid honing device. The abrasive grains 32 are applied to the outer peripheral surface of the resin layer 10A so as to be upstream from the position of the central axis C where the resin layer 10A is rotated. As a result, as shown in FIG. 6, the outer peripheral surface of the resin layer 10 </ b> A is roughened in a state where the outer peripheral surface of the resin layer 10 </ b> A is laid in one direction (rotation direction F during processing). That is, a large number of protrusions 20 are formed on the outer peripheral surface of the resin layer 10A so that the tips of the protrusions 20 formed on the outer peripheral surface of the resin layer 10A face one side in the circumferential direction (rotation direction F during processing). Is done.

  From the viewpoint of reliably improving the adhesion between the resin layer 10A and the metal layer 10B, the surface roughness Ra of the resin layer 10A is preferably in the range of 0.2 μm to 1.5 μm, preferably 0.3 μm to 1.0 μm. A range is more preferred. Here, the surface roughness of the outer peripheral surface of the resin layer 10A is an arithmetic average roughness Ra value measured according to an analysis standard: JIS B0601 (1994) by a surface roughness measuring machine (Surfcom 1500DX manufactured by Tokyo Seimitsu). is there.

The abrasive grains may be applied to a region on the downstream side of the position of the central axis C where the resin layer 10A is rotated as viewed from the direction in which the abrasive particles 32 are applied. The projection 20 is easy to be formed, which is advantageous.
Further, as described above, the method of roughening the outer peripheral surface of the resin layer 10A so that the direction of the protruding portion 20 has directionality along the circumferential direction is not limited to blasting, for example, A method of roughening the surface by free fall of abrasive grains may be employed. Also in this case, if the region where the abrasive grains are applied to the outer peripheral surface of the resin layer 10A is shifted from the central axis C, the protruding portion 20 inclined to one side in the circumferential direction is formed.
Furthermore, it is not limited to the method of roughening using the abrasive grains as described above, for example, a mold having an uneven pattern opposite to the pattern of the protrusions 20 to be formed on the outer peripheral surface of the resin layer 10A. May be used, and the mold 20 may be pressed against the outer peripheral surface of the resin layer 10A to form the protrusion 20.

[Base metal layer]
The base metal layer 10B is a layer provided to form the metal heating layer 10C on the outer peripheral surface of the resin layer 10A made of, for example, a heat resistant resin, and is formed as necessary. As a method for forming the metal heating layer 10C, an electrolytic plating method can be cited from the viewpoint of cost and the like, but it is difficult to perform electrolytic plating directly on the resin layer 10A formed of a heat resistant resin. Therefore, in order to form the metal heating layer 10C, the base metal layer 10B is necessary. As a method of forming such a base metal layer 10B, a chemical plating method is desirable, and general chemical nickel plating is particularly desirable.
The thickness of the base metal layer 10B is a thickness that does not impair the flexibility of the belt 10, and is, for example, in the range of 0.1 μm or more and 10 μm or less.

[Metal heating layer]
The metal heat generating layer 10 </ b> C is a layer having a function of generating heat by generating an eddy current by a magnetic field generated from a coil in the electromagnetic induction heating and fixing apparatus 100, and is made of a metal that generates an electromagnetic induction effect.
The metal that generates electromagnetic induction is selected from, for example, a single metal such as nickel, iron, copper, gold, silver, aluminum, chromium, tin, zinc, or an alloy (steel, etc.) composed of two or more elements. The In consideration of cost, heat generation performance, and workability, copper, nickel, aluminum, iron, and chromium are suitable, and copper or an alloy mainly composed of copper is particularly desirable.

  The appropriate thickness of the metal heat generating layer 10C differs depending on the material, but for example, when copper is used for the metal heat generating layer 10C, the thickness may be in the range of 3 μm to 50 μm. When the thickness of the metal heat generating layer 10C is less than 3 μm, the resistance value of the metal heat generating layer 10C becomes high, so that it becomes difficult to generate sufficient eddy current, heat generation is insufficient, and the warm-up time becomes long or fixing. It may not be heated enough to the possible temperature. Further, if the thickness of the metal heating layer 10C exceeds 50 μm, sufficient heat generation can be obtained, but the heat capacity of the layer itself increases, so the warm-up time may become longer.

[Protective layer]
The protective layer 10D is a layer provided on the heat generating layer 10C in order to suppress cracking due to repeated deformation of the heat generating layer 10C, oxidation deterioration due to repeated heating for a long time, and the like, and maintain heat generation characteristics. In particular, when the metal heating layer 10C containing copper as a main component is used, the strength is small and the resistance to repeated deformation is low. May decrease. Therefore, by providing the protective layer 10D on the heat generating layer 10C, generation of cracks and oxidation are suppressed.

The protective layer 10D is a thin film and may be made of an oxidation-resistant metal having high durability and oxidation resistance. As a method for forming the metal protective layer 10D, an electroplating method can be cited in consideration of workability with a thin film, and among them, electrolytic nickel plating that provides a metal film with high strength is desirable.
The appropriate thickness of the protective layer 10D varies depending on the material, but when nickel is used as the protective layer 10D, for example, the thickness is in the range of 2 μm to 20 μm. If the thickness of the protective layer 10D is 2 μm or more, the fracture strength is insufficient and the occurrence of cracks is suppressed. On the other hand, if the thickness of the protective layer 10D is 20 μm or less, the flexibility of the fixing belt 10 is maintained, and the increase in the heat capacity of the protective layer itself is suppressed, so that the warm-up time can be shortened.
The thicknesses of the metal heating layer 10C and the metal protective layer 10D are values measured with a fluorescent X-ray film thickness meter (manufactured by Fisher Instruments Co., Ltd.).

  The fixing belt 10 of the present embodiment has three metal layers (a base metal layer 10B, a metal heating layer 10C, and a metal protective layer 10D) on the outer peripheral surface of the resin layer 10A. The layer may be a single layer, two layers, or four or more layers. For example, the base metal layer 10B may not be provided, and the metal heating layer 10C may be directly provided on the outer peripheral surface of the resin layer 10A by a sputtering method or the like.

[Elastic layer]
The elastic layer 10E is a layer that plays a role of closely contacting the surface of the fixing belt 10 with the toner image following the unevenness of the toner image on the recording medium.
In particular, when forming a color image, it is necessary to fix the toner image in a state in which toners of four colors of monochrome black, magenta, yellow, and cyan are laminated on the recording medium, but the elastic layer 10E is not provided. When a rotating body (fixing belt) is used, the stacked toner may be crushed. Since sufficient heat is not applied to the toner close to the recording medium (that is, in the laminated lower layer), the color developability may be deteriorated. On the other hand, if the elastic layer 10E is provided, by applying heat to these four color toners laminated, the four colors are melted to obtain a clear color image, and the recording medium and the toner image are colored due to uneven heating. It is easy to obtain an image in which deterioration in gloss and gloss unevenness are suppressed.
Even in the case of forming a black and white image, if the elastic layer 10E is provided, the elastic layer 10E is deformed in the contact area between the fixing belt 10 and the pressure member (pressure roll), and even at a low load. Since a sufficient contact width can be obtained, heat is transferred to the toner and fixing is performed even at a high speed.

  The elastic layer 10E is a layer made of a material that can be restored to its original shape even when deformed by applying an external force of 100 Pa. Examples of the material constituting the elastic layer 10E include known elastic materials. For example, it is desirable to use heat-resistant rubber such as silicone rubber or fluorine rubber. Specifically, liquid silicone rubber SE6744 manufactured by Toray Dow Corning Silicone, Viton B-202 manufactured by DuPont Dow elastmers, etc. may be mentioned.

[Release layer]
The release layer 10 </ b> F is formed for the purpose of preventing the toner in the molten state from adhering to the heat fixing belt 10 when fixing the unfixed toner image as the heat fixing belt to the recording medium in a molten state. The release layer 10F may be provided as necessary.
The release layer 10F is preferably formed mainly of a fluorine compound. Examples of fluorine compounds include fluorine resins such as fluorine rubber, polytetrafluoroethylene (PTFE), perfluoroalkyl vinyl ether copolymer (PFA), and tetrafluoroethylene hexafluoropropylene copolymer (FEP). Can be mentioned.

  The thickness of the release layer 10F is, for example, 10 μm or more and 100 μm or less. When the thickness of the release layer 10F is 10 μm or more, the release layer 10F is prevented from being worn by repeated rubbing with the edge of the paper used as the recording medium. On the other hand, if the thickness of the release layer 10F is 100 μm or less, the flexibility of the surface of the belt 10 is ensured. As a result, the crushing force of the toner is suppressed, the granularity of the fixed image is maintained, and the warm-up time is shortened.

<Fixing device>
Next, an electromagnetic induction type fixing device 100 provided with the endless belt 10 as a fixing belt will be described.
As shown in FIG. 2, a pressure roll (pressure member) 11 is disposed so as to press a part of the fixing belt 10, and a contact region is formed between the fixing belt 10 and the pressure roll 11. Yes. In this contact region, the fixing belt 10 is curved along the peripheral surface of the pressure roll 11.

  The pressure roll 11 is configured such that an elastic body layer 11B made of silicone rubber or the like is formed on a base material 11A, and a release layer 11C made of a fluorine compound is formed on the elastic body layer 11B.

  A pressing member 13 is disposed inside the fixing belt 10 at a position facing the pressure roll 11. The pressing member 13 is made of metal, heat-resistant resin, heat-resistant rubber, or the like, and has a pad 13B that is in contact with the inner peripheral surface of the fixing belt 10 and locally increases the pressure, and a support 13A that supports the pad 13B.

  An electromagnetic induction heating device 12 including an electromagnetic induction coil (excitation coil) 12a is provided at a position facing the pressure roll 11 with the fixing belt 10 as the center. The electromagnetic induction heating device 12 applies an alternating current to the electromagnetic induction coil to change the generated magnetic field by an excitation circuit, and generates an eddy current in the metal heating layer 10 </ b> C of the fixing belt 10. This eddy current is converted into heat (Joule heat) by the electric resistance of the metal heating layer 10C, and as a result, the surface of the fixing belt 10 generates heat. The position of the electromagnetic induction heating device 12 is not limited to the position shown in FIG. 2. For example, the electromagnetic induction heating device 12 may be installed on the upstream side in the rotation direction B with respect to the contact area of the fixing belt 10. It may be installed inside.

In the electromagnetic induction heating type fixing device 100 according to the present embodiment, a driving force is transmitted to gears arranged at both ends of the fixing belt 10 by a driving device (not shown), so that the fixing belt 10 is self-aligned in the arrow B direction. The pressure roll 11 rotates in the reverse direction, that is, in the direction of arrow C as the fixing belt 10 rotates.
The recording material 15 on which the unfixed toner image 14 is formed is passed through the contact area between the fixing belt 10 and the pressure roll 11 in the fixing device 100 in the direction of arrow A to bring the unfixed toner image 14 into a molten state with pressure. Fixing is performed on the recording material 15.

  In the belt-driven fixing device 100 having such a configuration, the fixing belt 10 is formed in a circumferential direction on the side to which the tip 20A of the ridge-like protrusion 20 formed on the surface of the resin layer 10A faces (see FIGS. 3 (in the direction of arrow B in FIG. 3). By aligning the direction of the protrusions 20 formed on the outer peripheral surface of the resin layer 10A and the rotation direction of the fixing belt 10 in this way, the protrusions 20 of the resin layer 10A are wedged on the base metal layer 10B. Therefore, peeling between the resin layer 10A and the metal layer 10B is effectively suppressed.

  On the other hand, the pressure roller 11 may be a pressure roller driving type fixing device that self-rotates and rotates the fixing belt 10 as the pressure roller 11 rotates. In this case, the pressure roll 11 is rotated so that the fixing belt 10 rotates in the direction opposite to the circumferential direction on the side where the tip 20A of the protrusion 20 on the outer peripheral surface of the resin layer 10A faces. If the pressure roll 11 is rotated in this way, the fixing belt 10 rotates in a direction in which the base metal layer 10B is caught by the ridged protrusions 20 of the resin layer 10A, so that the resin layer 10A and the metal layer 10B Peeling is effectively suppressed.

<Image forming apparatus>
FIG. 7 schematically shows the image forming apparatus according to the present embodiment.
An image forming apparatus 200 according to this embodiment includes a photosensitive drum (image holding member) 202, a charging device (charging unit) 204, a laser scanner (electrostatic latent image forming unit) 206, a mirror 208, and a developing device (developing unit). 210, an intermediate transfer body 212, a transfer roll (transfer means) 214, a cleaning device 216, a static elimination device 218, a fixing device (fixing means) 100, and a paper feed device (paper feed unit 220, paper feed roller 222, registration roller 224, And a recording medium guide 226).

  When image formation is performed by the image forming apparatus 200, first, a non-contact type charging device 204 provided in the vicinity of the photosensitive drum 202 charges the surface of the photosensitive drum 202.

  Laser light corresponding to the image information (signal) of each color is irradiated from the laser scanner 206 through the mirror 208 to the surface of the photosensitive drum 202 charged by the charging device 204 to form an electrostatic latent image.

  The developing device 210 forms a toner image by applying toner to the latent image formed on the surface of the photosensitive drum 202. The developing device 210 is provided with developing devices (not shown) for the respective colors respectively containing toners of four colors, cyan, magenta, yellow, and black. The developing device 210 rotates in the direction of the arrow, thereby causing the photosensitive drum 202 to rotate. Each color toner is applied to the latent image formed on the surface of the toner to form a toner image.

  The toner images of the respective colors formed on the surface of the photoconductive drum 202 are brought into contact with the photoconductive drum 202 and the intermediate transfer body 212 by a bias voltage applied between the photoconductive drum 202 and the intermediate transfer body 212. The toner images of the respective colors are transferred onto the outer peripheral surface of the intermediate transfer body 212 so as to coincide with the image information.

The intermediate transfer member 212 has an outer peripheral surface that contacts the surface of the photosensitive drum 202 and rotates in the direction of arrow E.
In addition to the photosensitive drum 202, a transfer roll 214 is provided around the intermediate transfer body 212.

  The intermediate transfer member 212 to which the color toner image is transferred rotates in the direction of arrow E. The toner image on the intermediate transfer body 212 is transferred to the surface of the recording medium 15 conveyed to the contact portion in the direction of arrow A by the paper feeding device at the contact portion between the transfer roll 214 and the intermediate transfer body 212.

  The recording medium housed in the paper feeding unit 220 is fed by a recording medium push-up unit (not shown) built in the paper feeding unit 220 to feed the contact portion between the intermediate transfer body 212 and the transfer roll 214. When the recording medium 15 is pushed up to a position where it contacts the roller 222 and contacts the paper feed roller 222, the paper feed roller 222 and the registration roller 224 rotate to convey along the recording medium guide 226 in the direction of arrow A. Is done.

  The toner image transferred to the surface of the recording medium 15 moves in the direction of arrow A, and in the contact area between the fixing belt 10 and the pressure roll 11, the toner image 14 is pressed against the surface of the recording medium 15 in a molten state. It is fixed on the surface of the recording medium 15. Thereby, an image fixed on the surface of the recording medium is formed.

The surface of the photosensitive drum 202 after the toner image is transferred to the surface of the intermediate transfer member 212 is cleaned by the cleaning device 216.
The surface of the photosensitive drum 202 is cleaned by the cleaning device 216 and then discharged by the charge removing device 218.

  When the image forming apparatus 200 repeatedly forms an image, the fixing belt 10 is repeatedly curved in different directions in the contact area with the pressure roll 11, but by including the fixing apparatus 100 according to the present embodiment, Since the peeling between the resin layer 10A and the metal layer 10B of the fixing belt 10 is suppressed, the life of the fixing belt 10 can be extended.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

-Production of electromagnetic induction heating type fixing belt-
In Examples and Comparative Examples, fixing belts were basically produced according to the following steps.
First, a polyimide precursor solution (U-varnish S: manufactured by Ube Industries Co., Ltd.) is flow-coated onto a cylindrical mold (outer diameter: 5 cm) whose surface has been treated with a release agent (KS700: manufactured by Toray Industries, Inc.). Apply using. After drying at 100 ° C. for 30 minutes, it is placed in a furnace at 380 ° C. and baked for 60 minutes to form a resin layer (thickness 70 μm).

Next, as a base treatment of the base metal layer, a liquid honing device (LH-5: manufactured by Fuji Seiki Seisakusho Co., Ltd.) was used, and while rotating the mold, WA400: Showa Denko was sprayed on the surface of the resin layer to form a resin. Roughening is performed so that the surface roughness of the layer is Ra 0.5 μm.
On the surface of the roughened resin layer, an electroless nickel film having a thickness of 0.5 μm is formed as a base metal layer. In order to perform electroplating using this base metal layer as a cathode, power feeding portions are arranged outside the both ends of the sheet passing width in the belt axial direction.

  Next, an electrolytic copper plating film (thickness 15 μm) is sequentially formed as a heat generating layer, and an electrolytic nickel plating film (thickness 15 μm) is sequentially formed as a protective layer.

  Then, using a flow coat apparatus, the primer for the elastic layer (DY39-067: manufactured by Toray Dow Corning Silicone Co., Ltd.) and liquid silicone rubber (X34-1053A / B: manufactured by Shin-Etsu Chemical Co., Ltd.) were applied. dry. Next, an elastic layer (thickness: 250 μm) is formed by placing in a furnace at 200 ° C. and vulcanizing and firing.

Further, a primer for the release layer (No. 101A / B: manufactured by Shin-Etsu Chemical Co., Ltd.) is applied and dried at 100 ° C. for 30 minutes.
Thereafter, a PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) tube (thickness 30 μm), which becomes a release layer, is tube-coated using a tube coating machine, and is placed in a 200 ° C. oven and vulcanized and fired. To form a release layer.
The electromagnetic induction heating type fixing belt is completed through the above steps.

Example 1
In the surface roughening process of the resin layer using the liquid honing device, which is the base pretreatment of the base metal layer, as shown in FIG. 5, the region where the resin layer is roughened by the discharge nozzle is sprayed with abrasive grains. As seen from the direction to do, it was set to be upstream from the position of the rotation center axis of the mold. As a result, the surface of the resin layer was rolled up, and a large number of protruding portions (projections) were formed so that the tips of the protruding protrusions faced the rotation direction side of the resin layer.

  When this fixing belt is completed, the fixing belt rotates in the direction in which the ridged protrusions on the surface of the roughened resin layer pierce the underlying metal layer as a wedge (the circumferential direction on the side where the tip of the protrusion faces) A belt driving type electromagnetic induction heating type fixing belt is used.

(Example 2)
An electromagnetic induction heating type fixing belt was produced in the same procedure as in Example 1. This fixing belt is a belt driven type. When the fixing belt is pressed by the fixing roller and the fixing roller rotates, the base metal layer of the fixing belt protrudes from the outer peripheral surface of the resin layer. An electromagnetic induction heating type fixing belt in which the fixing belt rotates in the direction of being caught by the portion (the direction opposite to the circumferential direction on the side where the tip of the protruding portion faces) was used.

(Comparative Example 1)
In the surface roughening process using the liquid honing apparatus, which is a base pretreatment of the base metal layer, as shown in FIG. 8, the resin layer is roughened as seen from the direction in which the abrasive grains are ejected from the discharge nozzle. The center of the region was adjusted to the position of the rotation center axis of the mold. As a result, the surface of the resin layer subjected to the roughening process was formed with a sloped protrusion having a random and non-directional inclination.
This fixing belt was completed to obtain an electromagnetic induction heating type fixing belt for driving the belt.

(Evaluation)
The obtained fixing belt is mounted on an electromagnetic induction heating type fixing device (see FIG. 2) in the image forming apparatus having the configuration shown in FIG. 7, and 800,000,000 at a speed of 30 sheets / minute in a state of electromagnetic induction heating. A sheet passing test was conducted.
In the metal heating layer, when delamination between the resin layer and the base metal layer occurs, the stress balance of the belt layer configuration is lost, and the metal heating layer is cracked. The presence or absence of this crack can be determined by the change in the power factor, which is the electrical characteristic of the fixing belt. Therefore, every time 100,000 sheets are fixed, the power factor of the metal heating layer of the fixing belt is measured. The presence or absence of cracks was determined. The power factor is a value of cos θ based on the phase difference θ between the current and voltage flowing in the exciting coil as a result of the eddy current generated in the metal heating layer provided in the fixing belt by passing a high-frequency current through the exciting coil. The closer the phase difference θ is to 0, the higher the power factor, and the more easily the heat is generated.
In this embodiment, in the fixing device shown in FIG. 2, the magnetic field generation unit 12 is changed to an impedance meter (WT1600FC manufactured by Yokogawa Electric Corporation), and a phase difference between current and voltage when a high frequency current of 20 KHz is passed through the exciting coil. θ is measured, and the power factor (cos θ) is calculated. Here, the presence / absence of a crack was determined by confirming a rapid decrease on the basis of the power factor before the paper passing test.
The results are shown in Table 1.

As mentioned above, although embodiment and the Example were described, this invention is not limited to these.
For example, the protrusions on the outer peripheral surface of the resin layer 10A are not limited to the saddle-like protrusions as shown in FIGS. 3 and 4, but as shown in FIG. 9, a wavy or sawtooth shape extending in the width direction of the belt. The protruding portion 22 may be formed along the circumferential direction of the outer peripheral surface such that the tip 22A faces one side in the circumferential direction (arrow B direction).
Further, the configurations of the fixing device and the image forming apparatus are not limited to the configurations shown in FIGS. 2 and 7, respectively, and may be appropriately changed.

10 Fixing belt (endless belt)
10A Resin layer 10B Underlying metal layer 10C Metal heating layer 10D Metal protective layer 10E Elastic layer 10F Release layer 11 Pressure roll (pressure member)
11A Substrate 11B Elastic layer 11C Release layer 12 Electromagnetic induction heating device 13 Press member 13A Support body 13B Pad 14 Toner image 15 Recording medium 20 Protruding portion 20A Tip 22 Protruding portion 30 Discharge nozzle 32 Abrasive grain 100 Electromagnetic induction heating and fixing device 200 Image forming apparatus 202 Photosensitive drum 204 Charging apparatus 210 Developing apparatus 212 Intermediate transfer body 214 Transfer roll

Claims (6)

An annular resin having a plurality of protrusions along at least the circumferential direction of the outer peripheral surface, and wherein the plurality of protrusions are formed such that the tips of the plurality of protrusions face one side in the circumferential direction. Layers,
A metal layer formed on the outer peripheral surface of the resin layer;
With endless belt. The fixing belt according to claim 1, wherein the fixing belt rotates in a circumferential direction on a side to which each tip of the plurality of projecting portions of the resin layer faces.
Heating means for heating the metal layer of the fixing belt by electromagnetic induction;
A part of the outer peripheral surface of the fixing belt is pressurized, and the fixing belt rotates in a direction opposite to the circumferential direction when the fixing belt rotates in the circumferential direction on the side where the tips of the plurality of protrusions face. A pressure member;
A fixing device. A fixing belt which is an endless belt according to claim 1;
Heating means for heating the metal layer of the fixing belt by electromagnetic induction;
As the part of the outer peripheral surface of the fixing belt is rotated while being pressed, the fixing belt is rotated in the direction opposite to the circumferential direction on the side where the tips of the plurality of protrusions of the resin layer face. A pressure member;
A fixing device. An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic latent image forming unit that forms an electrostatic latent image on the surface of the image carrier charged by the charging unit;
Developing means for developing the electrostatic latent image with toner to form a toner image;
Transfer means for transferring the toner image to a recording medium;
A fixing device for fixing the toner image transferred to the recording medium to the recording medium, wherein the fixing device according to claim 2 or 3,
An image forming apparatus. An annular resin layer is prepared, the resin layer is rotated in the circumferential direction, and the region where the abrasive grains are applied to the outer peripheral surface of the resin layer is a central axis for rotating the resin layer as viewed from the direction of applying the abrasive grains By applying the abrasive grains to the outer peripheral surface of the resin layer so as not to overlap with the position of the plurality of protrusions, at least the periphery of the outer peripheral surface of the resin layer is arranged such that each of the protrusions faces the one side in the circumferential direction. Forming along the direction;
Forming a metal layer on the outer peripheral surface of the resin layer;
A process for producing an endless belt comprising:   The region where the abrasive grains are applied to the outer peripheral surface of the resin layer is located on the outer peripheral surface of the resin layer so that the region on the outer side of the resin layer is upstream of the position of the central axis that rotates the resin layer when viewed from the direction of applying the abrasive particles. The manufacturing method of the endless belt of Claim 5 which applies an abrasive grain.

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