JP6387843B2 - Fixing belt, fixing member, fixing device, and image forming apparatus - Google Patents

Description

  The present invention relates to a fixing belt, a fixing member, a fixing device, and an image forming apparatus.

In recent years, a fixing device for an image forming apparatus that performs fixing by heating a fixing belt by an electromagnetic induction heating method has been proposed.
For example, Patent Document 1 includes a metallic cylindrical body that is rotatably supported at both ends, and the cylindrical body is a thick part with a thicker end than an axially central part. A heating rotator is disclosed in which the cross-sectional shape is changed from the end to the center in the pressurizing region of the outer peripheral surface pressed by the pressure rotator, and the developer on the recording medium is heated. .

  Patent Document 2 includes a metal resin base material whose end is a thick part compared to the central part in the axial direction, and the axial sectional shape extends from the end part to the central part. A heating belt that changes and heats the developer on the recording medium, a support means that rotatably supports both ends of the heating belt, a heating means that heats the heating belt, and both ends can rotate. And a pressure rotator that pressurizes the outer peripheral surface of the heating belt and a receiving member that is provided inside the heating belt and receives the pressure of the pressure rotator. Yes.

  Patent Document 3 discloses an endless fixing belt provided with a metal layer having a surface treatment portion that generates a residual stress in the compression direction in the circumferential direction on the surface side.

JP 2010-224186 A JP 2010-224185 A JP 2012-2931 A

  The present invention includes a tubular resin substrate, a metal heating layer disposed on the resin substrate and generating electromagnetic induction heat, and disposed on the metal heating layer in contact with the metal heating layer. Compared to a fixing belt that satisfies one or both of the same thickness of the metal protective layer and the same crystallite size at both ends and the center, the occurrence of cracks in the metal layer at the one end An object of the present invention is to provide an electromagnetic induction heating type fixing belt that is suppressed.

  In order to achieve the above object, the following invention is provided.

The invention according to claim 1 is a tubular resin substrate;
A metal heating layer disposed on the resin substrate and generating electromagnetic induction heat; and
It is disposed on the metal heating layer in contact with the metal heating layer, and at least at one end in the belt width direction, the thickness is larger than the thickness in the central portion, and the crystallite size is larger than the crystallite size in the central portion. A metal protective layer having a small thick part;
A fixing belt having

The invention according to claim 2
The fixing belt according to claim 1, wherein the thick portion is provided at least in a terminal region of the one end portion of the metal protective layer.

The invention according to claim 3
The fixing belt according to claim 1, wherein the metal protective layer is a layer containing nickel.

The invention according to claim 4
The fixing belt according to any one of claims 1 to 3, wherein the resin base material has a tensile strength of 200 MPa or more.

The invention according to claim 5
The fixing belt according to any one of claims 1 to 4,
A rotation transmitting means fixed to one end portion of the metal protective layer of the fixing belt having the thick portion, and transmitting rotation to the fixing belt;
A fixing member having

The invention according to claim 6
A fixing member according to claim 5;
A pressure member that pressurizes an outer peripheral surface of the fixing belt of the fixing member and sandwiches a recording medium having an unfixed toner image formed on the surface together with the fixing member;
An electromagnetic induction heating device for generating heat by electromagnetic induction in the metal heating layer of the fixing belt;
A fixing device having

The invention according to claim 7 provides:
An image carrier,
A charging device for charging the surface of the image carrier;
A latent image forming apparatus for forming a latent image on the surface of the charged image carrier;
A developing device for developing a latent image formed on the surface of the image carrier with toner to form a toner image;
A transfer device for transferring a toner image formed on the surface of the image carrier to a recording medium;
The fixing device according to claim 6, wherein the toner image is fixed to the recording medium.
An image forming apparatus having

  According to the first aspect of the present invention, a tubular resin base material, a metal heat generation layer that is disposed on the resin base material and generates electromagnetic induction heat, and is disposed on the metal heat generation layer in contact with the metal heat generation layer. Compared with a fixing belt that satisfies one or both of the thickness of the metal protective layer and the same crystallite size at both ends and the center in the belt width direction, the metal at the one end An electromagnetic induction heating type fixing belt in which generation of cracks in a layer is suppressed is provided.

  According to the invention which concerns on Claim 2, generation | occurrence | production of the crack of the metal layer in the said one end part is suppressed compared with the case where it has the said thick part in area | regions other than a terminal area | region among the said one end parts of the said metal protective layer. An electromagnetic induction heating type fixing belt is provided.

  According to the invention of claim 3, electromagnetic induction heating having a metal protective layer that is superior in corrosion resistance and chemical resistance as compared with the case where the metal protective layer does not contain nickel and is made of iron. A fusing belt of the type is provided.

  According to the invention of claim 4, an electromagnetic induction heating type fixing belt in which the occurrence of cracks in the metal layer at the one end is suppressed as compared with the case where the tensile strength of the resin base material is less than 200 MPa. Is provided.

  According to the invention which concerns on Claim 5, it arrange | positions in contact with this metal heat generating layer on the said metal heat generating layer, the metal heat generating layer arrange | positioned on a tubular resin base material, the said resin base material, and electromagnetic induction heat_generation | fever And the metal protection of the fixing belt and the fixing belt satisfying one or both of the same thickness of the metal protective layer and the same crystallite size at both ends and the center in the belt width direction. The occurrence of cracks in the metal layer of the fixing belt at one end to which the rotation transmitting means is fixed is suppressed compared to a fixing member having a rotation transmitting means that is fixed to one end of the layer and transmits rotation to the fixing belt. An electromagnetic induction heating type fixing belt member is provided.

  According to the invention of claim 6 or 7, a tubular resin substrate, a metal heating layer disposed on the resin substrate and generating electromagnetic induction heat, and contacting the metal heating layer on the metal heating layer. Compared to the case where a fixing belt is applied that satisfies one or both of the same thickness of the metal protective layer and the same crystallite size at both ends and the center in the belt width direction. There is provided a fixing device or an image forming apparatus in which the occurrence of cracks in the metal layer at the one end of the fixing belt is suppressed.

FIG. 3 is a schematic cross-sectional view illustrating an example of a layer configuration of a fixing belt according to the present embodiment. FIG. 2 is a schematic perspective view illustrating an example of a fixing belt according to the present embodiment. FIG. 4 is a schematic diagram illustrating a relationship between a crystallite in a thick portion of a non-sheet-passing region (end portion) and a crystallite in a sheet-passing region (center portion) in the metal protective layer of the fixing belt according to the present embodiment. FIG. 6 is a schematic diagram illustrating an example of a method for forming a thick portion of a metal protective layer at one end portion of a fixing belt according to the present embodiment. It is a figure which shows an example of the fixing belt which concerns on this embodiment which has a drive gear in the one end part in which the thick part of the metal protective layer was formed. 1 is a schematic configuration diagram illustrating an example of a fixing device according to an exemplary embodiment. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. FIG. 3 is a schematic diagram illustrating an example of a fixing member in which a driving gear is bonded to one end portion of a fixing belt.

  Embodiments of the present invention will be described below with reference to the drawings.

<Fixing belt>
The fixing belt according to the present embodiment is arranged on a tubular resin base material, a metal heat generating layer that is disposed on the resin base material and generates electromagnetic induction heat, and is disposed on the metal heat generating layer in contact with the metal heat generating layer. , At least at one end in the belt width direction, a thick portion (hereinafter referred to as “thin crystallized thickness”) having a thickness larger than the thickness in the central portion and a crystallite size smaller than the crystallite size in the central portion. A metal protective layer having a “thick part” or simply “thick part”.

  In the fixing device using the electromagnetic induction heating method, for example, a fixing belt having a configuration in which a metal heating layer that generates heat by electromagnetic induction, a metal protective layer that protects the metal heating layer, and the like is laminated on the outer peripheral surface of a tubular base material layer is used. Then, the toner image is fixed on the surface of the recording medium by passing the recording medium on which the unfixed toner image is formed in the central portion excluding both ends.

  FIG. 8 is a schematic diagram illustrating an example of a fixing member in which a driving gear (an example of a rotation transmission unit) is fixed to one end portion of the fixing belt. As shown in FIG. 8, a driving gear 102 is bonded as a rotating mechanism to one end of the fixing belt 110 in the width direction (axial direction) to fix an unfixed toner image formed on the surface of the recording medium. At this time, the driving gear 102 is rotated by receiving a rotational force from a motor (not shown), and the rotational force is transmitted to the fixing belt 110 via the driving gear 102, whereby the fixing belt 110 rotates in the circumferential direction.

  When the fixing belt 110 is rotated through the driving gear 102 bonded to one end as described above, stress is concentrated around the portion of the fixing belt 110 where the driving gear 102 is bonded, and the usage time is increased. As a result, cracks 104 are likely to occur in the metal layer (metal protective layer and metal heating layer). In particular, if the crack 104 of the metal heat generating layer extends to the sheet passing area at the center of the belt, the amount of heat generated for fixing the toner image cannot be obtained, which may cause fixing failure.

  By using the fixing belt according to this embodiment, the occurrence of cracks in the metal layer is suppressed. The reason is considered as follows. In other words, the Young's modulus of the metal protective layer is improved by having a thick part where the metal protective layer is thickened at one end of the belt, and residual compressive stress is applied by refining the crystallites in the thick part. Further, durability against cracks in the metal protective layer is improved. It is considered that the occurrence of cracks in the metal heat generating layer protected by the metal protective layer is suppressed by making the metal protective layer difficult to crack.

  FIG. 1 is a schematic configuration diagram illustrating an example of a fixing belt according to the present embodiment, and FIG. 2 is a schematic perspective view of the fixing belt illustrated in FIG. 1. A fixing belt 10 shown in FIG. 1 includes a base metal layer 10B, a metal heat generation layer 10C that self-heats by electromagnetic induction, a metal protective layer 10D, and an elastic body layer 10E on the outer peripheral surface of a tubular resin base material 10A. And an endless belt having a layer structure in which a release layer 10F is sequentially laminated.

  When the fixing belt 10 according to the present embodiment is incorporated in a fixing device, as illustrated in FIG. 2, a sheet passing area 10 </ b> K through which a recording medium on which a toner image 14 is formed passes at the center in the belt width direction, And a non-sheet passing area 10J through which the recording medium does not pass at both ends in the belt width direction.

  FIG. 3 schematically shows the relationship between the crystallites in the thick part and the crystallites in the sheet passing area 10K in the metal protective layer of the fixing belt according to the present embodiment. In FIG. 3, the base metal layer 10B and the release layer 10F are omitted. As shown in FIG. 3, the metal protective layer 10D of the fixing belt 10 according to this embodiment has a thick portion 10DF having a thickness larger than the thickness of the sheet passing region 10K in the non-sheet passing region 10J at one end in the width direction. However, the crystallite size in the thick portion 10DF is smaller than the crystallite size in the paper passing region 10K.

  Hereinafter, each layer constituting the fixing belt 10 according to the present embodiment will be described in more detail. Note that reference numerals of the respective layers may be omitted in the description.

[Resin substrate 10A]
The resin base material 10A is preferably a layer that maintains high strength with little change in physical properties even when the adjacent metal heat generation layer 10C generates heat. For this reason, it is preferable that the resin base material 10A is mainly composed of a heat resistant resin (in the present specification, “mainly” and “main component” mean that the mass ratio is 50% or more, The following are also synonymous):

  In the case of the resin base material 10A mainly composed of a heat resistant resin, slidability with the pressing member in contact with the inner peripheral surface of the fixing belt is ensured, and the life of the pressing member is extended. Furthermore, since the heat resistant resin has a heat insulating effect, the heat generated in the metal heating layer 10C can be efficiently used without escaping to the pressing member.

Examples of the heat-resistant resin that can constitute the resin substrate 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 improve the heat insulation effect further 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 base material 10A is preferably in the range of 10 μm or more and 200 μm or less, and preferably in the range of 30 μm or more and 100 μm or less, from the viewpoint of achieving both rigidity and flexibility for realizing long-term repetitive circumferential conveyance of the fixing belt. More desirable.

  Further, from the viewpoint of suppressing the occurrence of cracks in the metal layer, the tensile strength of the resin base material 10A preferably satisfies a tensile strength measured as described later of 200 MPa or more (desirably 250 MPa or more). The tensile strength of the resin substrate can be adjusted by the type of resin, the type of filler, and the amount added.

[Base metal layer 10B]
The base metal layer 10B is a layer formed in advance for forming the metal heating layer 10C on the outer peripheral surface of the resin base material 10A made of a heat-resistant resin by an electrolytic plating method, for example, and is provided as necessary. .
As a method for forming the metal heating layer 10C, an electrolytic plating method is desirable from the viewpoint of cost and the like, but when the resin base material 10A mainly composed of a resin is used, it is difficult to perform the direct electrolytic plating. Therefore, the base metal layer 10B is necessary for forming the metal heating layer 10C.

  Examples of the method for forming the base metal layer 10B on the outer peripheral surface of the resin substrate 10A include an electroless plating method, a sputtering method, a vapor deposition method, and the like. From the viewpoint of film formation ease, a chemical plating method (electroless plating method). Of these, a general electroless nickel layer is desirable.

  In addition, before forming the base metal layer 10B on the outer peripheral surface of the resin base material 10A by the electroless plating method, the surface roughness of the outer peripheral surface of the resin base material 10A is roughened in advance so that the metal particles are easily attached. (Roughening treatment) may be applied. Examples of the roughening treatment include a method of roughening the surface of the resin base material 10A by sandblasting using alumina abrasive grains, cutting, sandpaper polishing, or the like.

  The thickness of the base metal layer 10B is desirably in the range of 0.1 μm to 5 μm, and more desirably in the range of 0.3 μm to 3 μm.

  The thickness of each layer constituting the fixing belt according to the present embodiment is determined by accelerating voltage of a scanning electron microscope (“JSM6700F” manufactured by JEOL Ltd.) by preparing a cross-section in the circumferential direction and axial direction of the fixing belt cylindrical body. It is the value which measured the film thickness from the observation image in 2.0 kV and 5000 times.

[Metal heating layer 10C]
The metal heat generating layer 10C is a heat generating layer having a function of generating heat by an eddy current generated in this layer when a magnetic field is applied, and is made of a metal that generates an electromagnetic induction effect.
As a metal that generates electromagnetic induction, for example, a single metal such as nickel, iron, copper, gold, silver, aluminum, chromium, tin, zinc, or an alloy containing two or more kinds of metals may be selected. . In consideration of cost, heat generation performance, and workability, copper, nickel, aluminum, iron, and chromium are suitable, and among these, copper or an alloy containing copper as a main component is particularly desirable.

  The metal heating layer 10C is formed by performing a well-known method, for example, electrolytic plating.

  The optimum thickness of the metal heating layer 10C differs depending on the metal material. For example, when copper is used for the metal heating layer 10C, the thickness of the metal heating layer 10C is 3 μm or more from the viewpoint of efficiently generating heat. The range is preferably 50 μm, more preferably 3 μm or more and 30 μm, and still more preferably 5 μm or more and 20 μm.

[Metal protective layer 10D]
The metal protective layer 10D improves the film strength of the metal heating layer 10C, suppresses cracking due to repeated deformation, oxidation deterioration due to repeated heating for a long time, and the like, and maintains the heat generation characteristics. This is a layer provided in contact with the metal heating layer 10C.

  The metal protective layer 10D is preferably a thin film that has breaking strength, high durability and high oxidation resistance, and is preferably an oxidation resistant metal. Specifically, for example, it may be configured to contain copper or nickel, and is particularly an oxidation-resistant metal from the viewpoint of suppressing the occurrence of cracks due to repeated deformation and oxidative deterioration due to repeated heating. Nickel (or nickel alloy) is desirable.

  The metal protective layer 10D of the fixing belt 10 according to the present embodiment has a thick portion 10DF having a thickness larger than the thickness of the paper passing region 10K in the non-sheet passing region 10J at one end in the width direction. The crystallite size is smaller than the crystallite size of the paper passing region 10K.

  The thickness of the metal protective layer 10D differs depending on the material, but for example, when the metal protective layer 10D is formed of nickel, flexibility is obtained while suppressing the occurrence of cracks due to insufficient fracture strength, The thickness of the metal protective layer 10D in the paper passing region 10K is preferably in the range of 2 μm or more and 20 μm or less, preferably in the range of 2 μm or more and 15 μm or less, from the viewpoint of keeping the heat capacity of the film itself too large and keeping the warm-up time short. It is more preferable that it is in the range of 5 μm or more and 10 μm or less.

  On the other hand, the thickness of the thick portion 10DF of the metal protective layer 10D in the paper passing region 10K is preferably in the range of 9 μm to 20 μm, more preferably in the range of 9 μm to 15 μm, and more preferably in the range of 10 μm to 15 μm. More preferably, it is in the range.

  Further, the difference between the thickness of the thick portion 10DF of the metal protective layer 10D in the paper passing area 10K and the thickness of the metal protective layer 10D in the paper passing area 10K is preferably in the range of 100 nm or more and 3 μm or less, and 500 nm or more and 2 More preferably, it is in the range of 0.5 μm or less, and more preferably in the range of 1 μm or more and 2.0 μm or less.

Further, in the fixing belt 10 according to the present embodiment, the crystallite size in the thick portion 10DF of the metal protective layer 10D is smaller than the crystallite size in the paper passing area 10K.
The crystallite size of the metal protective layer 10D in the paper passing region 10K is preferably in the range of 140 nm to 200 nm, more preferably in the range of 150 nm to 190 nm, and further in the range of 160 nm to 180 nm. preferable.
On the other hand, the crystallite size in the thick portion 10DF of the metal protective layer 10D is preferably in the range of 40 nm to 100 nm, more preferably in the range of 50 nm to 90 nm, and in the range of 60 nm to 80 nm. More preferably.

  In the present embodiment, the crystallite size in the metal protective layer 10D is obtained by measuring the particle size of the metal crystallite by X-ray diffraction (XRD). Specifically, as an X-ray diffractometer, measurement is performed using a fully automatic horizontal multipurpose X-ray diffractometer SmartLab manufactured by Rigaku Corporation.

-Method of forming metal protective layer 10D-
As a method for forming the metal protective layer 10D, in consideration of workability in a thin film, an electrolytic plating method is preferable, and an electrolytic nickel plating having a high strength is more preferable.

  When the metal protective layer 10D according to the present embodiment is formed by an electrolytic plating method, the electrolytic plating method is performed so that the thickness is greater than the thickness at the central portion at least at one end in the belt width direction. For example, the metal protective layer 10D corresponding to the thickness of the paper passing region is formed on the metal heating layer 10C by the electrolytic plating method including the one end (non-paper passing region). Next, electrolytic plating is performed again in a state where the paper passing area is masked, so that the thickness of the metal protective layer at one end is made thicker than the thickness of the metal protective layer in the paper passing area. At this time, in order to suppress a step at the boundary between the central portion serving as the paper passing region and the end serving as the non-paper passing region of the metal protective layer, the position from the boundary between the non-paper passing region and the paper passing region is changed to the end. It is preferable to give the thickness an inclination so that the thickness becomes larger.

  FIG. 4 shows an example of a method of increasing the thickness of the metal protective layer 10D at one end with an inclination. First, the metal protective layer 10D corresponding to the thickness of the paper passing region is formed on the metal heating layer 10C by electrolytic plating. Next, as shown in FIG. 4, masking 32 is applied to the end portion of the metal protective layer 10 </ b> D other than the region where the thick portion 10 </ b> DF is formed, and the end of the tubular body (to-be-plated object) 30 where the metal heating layer 10 </ b> D is exposed. Electrolytic plating is performed while rotating the tubular body 30 in the circumferential direction in a state where the tubular body 30 is inclined so as to be close to the planar electrode 34 in the plating solution 36. According to such a method, the thickness of the metal protective layer 10D increases as the position is closer to the flat electrode 34, that is, closer to the end, and the metal protective layer 10D having the thick portion 10DF with the inclined thickness can be formed. .

In order to suppress the occurrence of cracks in the metal layer, it is preferable that the thick-walled portion 10DF with fine crystallites is formed in the widest possible region of the one end that becomes the non-sheet passing region. The entire region need not be the thick portion 10DF, and the thick portion 10DF may be formed in at least a part of the non-sheet passing region. From the viewpoint of suppressing the occurrence of cracks in the metal layer, at least one end portion is thick at the end region (the region including the belt end of the non-paper passing region at one end portion in the belt width direction) to which the drive gear is bonded. 10DF is preferably formed.
Further, when the thick portion 10DF of the metal protective layer 10D is formed in the non-sheet passing regions at both ends, the thick portion 10DF may be formed in the same manner for the other end portion.

  After the thick portion 10DF is formed on the metal protective layer 10D in the non-sheet-passing region, the fine processing is performed so that the crystallite size of the thick portion 10DF is smaller than the crystallite size of the metal protective layer 10D in the paper-passing region. Apply. A method for refining the crystallites of the thick portion 10DF of the metal protective layer 10D is not particularly limited, but a method of performing shot peening on the thick portion 10DF can be mentioned.

  Specifically, after forming the metal protective layer 10D having the thick portion 10DF in the non-sheet-passing region, particles such as glass beads having a particle diameter of 10 μm or more and 200 μm or less are predetermined with respect to the thick portion 10DF. For example, particles are ejected at an ejection speed of 100 m / sec or more by the discharge pressure.

  By injecting particles onto the thick part 10DF of the metal protective layer 10D, the crystallites are refined, and a dense, high hardness and tough structure is obtained. And the internal residual compressive stress of a surface is raised.

[Elastic layer 10E]
The elastic body layer 10E is a layer that plays the role of closely contacting the surface of the fixing belt with the toner image following the unevenness of the toner image on the recording medium. In particular, when forming a color image, the elastic layer 10E provides an image in which the color development deterioration and gloss unevenness due to heating unevenness of the recording medium and the toner image are suppressed. Further, since the elastic layer 10E is deformed in the contact region with the pressure member and a contact width is obtained even at a low load, the heat to the toner image is increased even if the process speed (recording medium conveyance speed) is increased. Even when the image is transferred and fixed, and a black and white image is formed, the speed can be increased.

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

  The thickness of the elastic body layer 10E is, for example, in the range of 0.1 mm to 3 mm, and preferably 0.15 mm to 1 mm.

[Release layer 10F]
The release layer 10 </ b> F is a layer that plays a role of preventing the toner image in a molten state from adhering to the surface (outer peripheral surface) on the side in contact with the recording medium. The release layer 10F is provided as necessary.

  The release layer 10F is preferably configured to include a low surface energy material such as a fluorine-based compound as a main component. Examples of the fluorine compound include fluororubber, polytetrafluoroethylene (hereinafter referred to as “PTFE”), perfluoroalkyl vinyl ether copolymer (hereinafter referred to as “PFA”), ethylene tetrafluoride ethylene hexafluoride propylene copolymer. A fluororesin such as a polymer (hereinafter referred to as “FEP”) is exemplified, but it is not particularly limited.

  The thickness of the release layer 10F is preferably in the range of 10 μm to 100 μm, and more preferably in the range of 20 μm to 50 μm. When the thickness of the release layer 10F is 10 μm or more, wear of the release layer 10F due to repeated friction at the edge of the paper is suppressed. Further, when the thickness of the release layer 10F is 100 μm or less, the surface flexibility is maintained, the granularity of the fixed image is maintained, and the warm-up time is shortened.

The elastic layer 10E and the release layer 10F may be formed by a known method, for example, sequentially formed on the metal protective layer 10D by a coating method.
When the elastic body layer 10E and the release layer 10F are formed on the metal protective layer 10D by a coating method, the surface of the metal protective layer 10D or the elastic body layer 10E is necessary before the formation of these layers. Accordingly, it is desirable to perform pretreatment with an appropriate primer material. By performing this pretreatment, the adhesion between the layers is further improved.

  In addition, when the elastic body layer 10E and the release layer 10F are laminated and formed on the metal protective layer 10D by a coating method, the elastic body layer 10E and the release layer are subjected to a process of heat-treating the coated film. 10F is formed. The heat treatment of the coating film may be performed in an inert gas (nitrogen gas, argon gas, etc.) atmosphere.

<Fixing member>
The fixing member according to the present embodiment is fixed to one end of the fixing belt according to the present embodiment and the thick protective portion of the metal protective layer of the fixing belt, and transmits rotation to the fixing belt. Means.

FIG. 5 schematically shows an example in which a drive gear is provided as a rotation transmitting means for transmitting rotation to the fixing belt at one end of the fixing belt according to the present embodiment. The fixing belt 10 according to the present embodiment is incorporated in a fixing device in a state in which a driving gear 42 is fixed to one end in order to rotate the fixing belt 10 in the circumferential direction.
In the fixing belt member shown in FIG. 5, the drive gear 42 is bonded to one end portion having a thick portion where the crystallites of the metal protective layer of the fixing belt 10 are miniaturized. Specifically, a driving gear 42 as a driving member for rotating the fixing belt 10 in the circumferential direction is provided at one end portion having a thick portion where the crystallites of the metal protective layer of the tubular fixing belt 10 are miniaturized. ing. A convex flange member 44 is integrally formed on the side of the fixing belt 10 of the drive gear 42 so as to be in surface contact with the inner peripheral surface of the fixing belt 10. The outer peripheral surface of the flange member 44 and the inner peripheral surface (resin base material 10A) of the fixing belt 10 are bonded with an adhesive, and the drive gear 42 that rotates by receiving a rotational force from a motor (not shown) is the flange. A rotational force is transmitted to the fixing belt 10 via the member 44.

  In the fixing member according to the present embodiment, from the viewpoint of suppressing cracks in the metal layer, at least one end region of the metal protective layer bonded to the flange member 44 of the drive gear 42 is formed on the thick portion 10DF. It is preferable that

<Fixing device>
The fixing belt according to the present embodiment presses the fixing member according to the present embodiment and the outer peripheral surface of the fixing belt of the fixing member, and the recording medium on which the unfixed toner image is formed is used as the fixing member. And a pressure member sandwiched together, and an electromagnetic induction heating device for generating heat by electromagnetic induction in the metal heating layer of the fixing belt.

FIG. 6 is a schematic configuration diagram illustrating an example of a fixing device according to the present embodiment.
The fixing device 100 according to the present embodiment is an electromagnetic induction type fixing device including the fixing belt 10 according to the present embodiment. As shown in FIG. 6, a pressure roll (pressure member) 11 is disposed so as to press a part of the fixing belt 10, and contact is made between the fixing belt 10 and the pressure roll 11 from the viewpoint of efficient fixing. A region (nip) is formed, and the fixing belt 10 is curved along the circumferential surface of the pressure roll 11. Further, from the viewpoint of ensuring the releasability of the recording medium, a bent portion where the fixing belt is bent is formed at the end of the contact area (nip).

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

  A facing member 13 is disposed inside the fixing belt 10 at a position facing the pressure roll 11. The facing 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 (an example of a pressure member) with the fixing belt 10 as a center. The electromagnetic induction heating device 12 applies an alternating current to the electromagnetic induction coil, thereby changing the generated magnetic field by an excitation circuit and generating 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. 6. 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 fixing device 100 according to the present embodiment, a driving force is transmitted by a driving device (not shown) to a gear (not shown in FIG. 6) fixed to the end of the fixing belt 10 where the thick metal protective layer is formed. As a result, the fixing belt 10 self-rotates in the direction of arrow B, and 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 medium 15 on which the unfixed toner image 14 is formed is passed through a contact area (nip) between the fixing belt 10 and the pressure roll 11 in the fixing device 100 in the direction of arrow A, and the unfixed toner image 14 is in a molten state. Is applied to the recording medium 15 by applying pressure.

<Image forming apparatus>
The image forming apparatus according to the present embodiment includes an image carrier, a charging device that charges the surface of the image carrier, a latent image forming device that forms a latent image on the charged surface of the image carrier, and the image. A developing device for developing a latent image formed on the surface of the holding body with toner to form a toner image, a transfer device for transferring the toner image formed on the surface of the image holding body to a recording medium, and the toner image And a fixing device according to this embodiment for fixing the image to the recording medium.

FIG. 7 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present embodiment.
As shown in FIG. 7, the image forming apparatus 200 according to the present embodiment includes a photosensitive member (an example of an image holding member) 202, a charging device 204, a laser exposure device (an example of a latent image forming device) 206, a mirror 208, and development. Device 210, intermediate transfer body 212, transfer roll (an example of a transfer device) 214, cleaning device 216, static eliminator 218, fixing device 100, and 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 with the image forming apparatus 200, first, a non-contact type charging device 204 provided in the vicinity of the photoconductor 202 charges the surface of the photoconductor 202.

  Laser light corresponding to the image information (signal) of each color is irradiated from the laser exposure device 206 through the mirror 208 on the surface of the photosensitive member 202 charged by the charging device 204, thereby forming 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 photoreceptor 202. The developing device 210 includes developing devices (not shown) for the respective colors, each containing toners of four colors, cyan, magenta, yellow, and black. Each color toner is applied to the latent image formed on the surface to form a toner image.

  The toner images of the respective colors formed on the surface of the photoconductor 202 are changed in color at the contact portion between the photoconductor 202 and the intermediate transfer body 212 by a bias voltage applied between the photoconductor 202 and the intermediate transfer body 212. Each toner image is 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 member 202 and rotates in the direction of arrow E.
In addition to the photoconductor 202, a transfer roll 214 is provided around the intermediate transfer body 212.

  The intermediate transfer member 212 onto which the color toner image has been 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 the toner image 14 is melted on the surface of the recording medium 15 in the contact area (nip) between the fixing belt 10 and the pressure roll 11. It is pressed and 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 photoconductor 202 after the toner image is transferred to the surface of the intermediate transfer body 212 is cleaned by the cleaning device 216.
The surface of the photoconductor 202 is cleaned by the cleaning device 216 and then discharged by the charge removing device 218.

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

[Example 1]
-Preparation of Resin Substrate X An NMP solution of a polyimide precursor (polyimide varnish “U-imide AH” (manufactured by Unitika Ltd.)) was applied on a φ30 mm mold by flow coating and stepped up to 380 ° C. ( 25 ° C. → 120 ° C. 1 hr → 250 ° C. 1 hr → 380 ° C. 1 hr → 25 ° C.).
As a result, a seamless resin tubular body made only of polyimide (resin single layer) having an inner diameter of 30 mm and a film thickness of 60 μm was obtained.

  The tubular resin substrate X thus obtained had an inner diameter of 30 mm, a thickness of 60 μm, and a width of 400 mm.

The surface of a tubular polyimide substrate (hereinafter abbreviated as “PI substrate”) having an inner diameter of 30 mm, a thickness of 60 μm, and a width of 400 mm obtained as described above was applied to a liquid honing apparatus (LH-8TTHiS manufactured by Fuji Seiki). And roughening treatment (surface roughness Ra = 0.5 μm or more and 1.0 μm or less).
Honing conditions were as follows: abrasive grain # 320, injection pressure 0.3 MPa, injection distance 100 mm, and processing time 1.5 minutes.
Then, the abrasive grains on the surface of the roughened PI base material were washed away with ion-exchanged water, and then moisture on the PI base material surface was removed with compressed air.

-Formation of metal underlayer Next, the PI base material was incorporated in a plating jig, and an electroless copper plating layer (metal underlayer) having a thickness of 0.5 µm was formed by electroless plating.

-Formation of a metal heating layer After forming an electroless copper plating layer (metal underlayer), electrodes are set on both ends of the plating jig, and subjected to electrolytic plating treatment with a copper sulfate plating solution. A metal exothermic layer) was formed.

-Formation of a metal protective layer Next, it was immersed in a plating solution containing nickel ions to perform electrolytic plating of nickel, thereby forming an electrolytic nickel layer having a thickness of about 9 µm.
Further, nickel electroplating was performed while the tubular body masked in a region other than 40 mm at one end was tilted so that one end where the nickel layer was exposed approached the planar electrode and rotated in the circumferential direction. Thereby, the nickel layer was further thickened between 40 mm from the end, and a nickel layer having a gradient in thickness was formed in a range where the difference from the thickness of the nickel layer in the paper passing region was 0.5 μm or more and 3 μm or less.
Similarly, in the 40 mm region at the opposite end, a nickel layer having an inclined thickness was formed in the range where the difference from the thickness of the nickel layer in the paper passing region was 0.5 μm or more and 3 μm or less.
Subsequently, areas other than 40 mm at both ends were masked, and shot peening was performed on both ends (thick portions) using glass beads.

-Formation of elastic body layer and release layer Next, silicone rubber was applied to the surface (outer peripheral surface) of the tubular body using a spiral coat apparatus (thickness 200 µm), and after primary vulcanization (120 ° C x 20 min), A PFA tube (thickness 30 μm, with an inner surface adhesive layer) was covered, and adhesion firing (200 ° C. × 4 h) was performed. Thus, after sequentially forming the elastic layer and the release layer on the surface (outer peripheral surface) of the endless belt, both end portions 15 mm were cut off, and a gear was adhered to the inner peripheral surface of one end of the PI base material to form a fixing belt. .

[Comparative Example 1]
In the production of the fixing belt of Example 1, a fixing belt was produced in the same manner as in Example 1 except that the metal protective layers (nickel layers) at both ends were not thickened and shot peening was not carried out. .

[Comparative Example 2]
In the production of the fixing belt of Example 1, a fixing belt was produced in the same manner as in Example 1 except that shot peening was not performed.

[Comparative Example 3]
In the production of the fixing belt of Example 1, a fixing belt was produced in the same manner as in Example 1 except that the metal protective layer (nickel layer) at both ends was not thickened.

[Example 2]
A fixing belt was produced in the same manner as in Example 1 except that the resin substrate Y produced as described below was used in the production of the fixing belt of Example 1.

-Preparation of resin substrate Y Resin substrate Y was prepared in the same manner as in Example 1 except that "U-imide CH" (manufactured by Unitika Ltd.) was used as the polyimide varnish in the preparation of resin substrate X of Example 1. Produced.

[Evaluation method]
-Measurement of nickel layer thickness-
The thickness of the metal protective layer (nickel layer) was measured for the cross section of the fixing belt produced in each example from the observation image at an acceleration voltage of 2.0 kV and 5000 times of a scanning electron microscope (“JSM6700F” manufactured by JEOL Ltd.).

-Crystallite size measurement-
With respect to the metal protective layer (nickel layer), the particle size of the metal crystallites was measured by X-ray diffraction (XRD) from the belt end toward the center to a position of 50 mm. As an X-ray diffractometer, a fully automatic horizontal multipurpose X-ray diffractometer SmartLab manufactured by Rigaku Corporation was used.

-Measurement of tensile strength of resin substrate-
The tensile strength (MPa) of the resin base material was measured as follows.
The resin base material was cut into a strip shape having a width of 5 mm, and this was installed in a tensile tester Model 1605N (manufactured by Aiko Engineering Co., Ltd.), and the tensile breaking strength (MPa) when pulled at a constant speed of 10 mm / sec was measured.

-Actual machine test-
After fixing and fixing a gear to one end of the fixing belt obtained in each example, it is mounted on a fixing device of an image forming apparatus (trade name: DocuCentre-IV C5570, manufactured by Fuji Xerox Co., Ltd.), and A4 paper is continuously used. Output was performed, and the number of outputs until a crack occurred in the belt portion at the gear side end of the fixing belt was investigated.

DESCRIPTION OF SYMBOLS 10 Fixing belt 10A Resin base material 10B Metal base layer 10C Metal heating layer 10D Metal protective layer 10DF Thick part 10E Elastic body layer 10F Release layer 10K Paper passing area (belt edge part)
10J Non-paper passing area (belt center)
DESCRIPTION OF SYMBOLS 11 Pressure roll 11A Base material 11B Elastic body layer 11C Release layer 12 Electromagnetic induction heat generating apparatus 13 Opposing member 13A Support body 13B Pad 14 Toner image 15 Recording medium 42 Drive gear (an example of rotation transmission means)
DESCRIPTION OF SYMBOLS 100 Fixing apparatus 200 Image forming apparatus 202 Photoconductor 204 Charging apparatus 206 Exposure apparatus 210 Development apparatus 212 Intermediate transfer body 214 Transfer roll

Claims (7)

A tubular resin substrate;
A metal heating layer disposed on the resin substrate and generating electromagnetic induction heat; and
It is disposed on the metal heating layer in contact with the metal heating layer, and at least at one end in the belt width direction, the thickness is larger than the thickness in the central portion, and the crystallite size is larger than the crystallite size in the central portion. A metal protective layer having a small thick part;
Having a fixing belt.   The fixing belt according to claim 1, wherein the thick portion is provided at least in a terminal region of the one end portion of the metal protective layer.   The fixing belt according to claim 1, wherein the metal protective layer is a layer containing nickel.   The fixing belt according to any one of claims 1 to 3, wherein the resin base material has a tensile strength of 200 MPa or more. The fixing belt according to any one of claims 1 to 4,
A rotation transmitting means fixed to one end portion of the metal protective layer of the fixing belt having the thick portion, and transmitting rotation to the fixing belt;
A fixing member. A fixing member according to claim 5;
A pressure member that pressurizes an outer peripheral surface of the fixing belt of the fixing member and sandwiches a recording medium having an unfixed toner image formed on the surface together with the fixing member;
An electromagnetic induction heating device for generating heat by electromagnetic induction in the metal heating layer of the fixing belt;
A fixing device. An image carrier,
A charging device for charging the surface of the image carrier;
A latent image forming apparatus for forming a latent image on the surface of the charged image carrier;
A developing device for developing a latent image formed on the surface of the image carrier with toner to form a toner image;
A transfer device for transferring a toner image formed on the surface of the image carrier to a recording medium;
The fixing device according to claim 6, wherein the toner image is fixed to the recording medium.
An image forming apparatus.