JP2014182292A - Fixing belt, fixing device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing belt that has excellent heating efficiency of a fixing target material, and suppresses the occurrence of image defects due to uneven application of pressure to the fixing target material.SOLUTION: A fixing belt 10 is configured of, for example, a base material layer 11, a heating layer 12 arranged on an outer peripheral side of the base material layer 11, an elastic layer 13A arranged on an outer peripheral side of the heating layer 12, an elastic layer 13B arranged on an outer peripheral side of the elastic layer 13A, and a release layer 14 arranged on an outer peripheral side of the elastic layer 13B. The elastic layer 13A is made to have thermal conductivity higher than thermal conductivity of the elastic layer 13B, and the elastic layer 13B is made to have an elastic modulus lower than an elastic modulus of the elastic layer 13A.

Description

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

As a fixing roller provided in a fixing device for an image forming apparatus, for example, the following rotary heating member is disclosed.
Japanese Patent Laid-Open No. 2004-133867 discloses that “a heat resistance Rt (° C./W) per cm ^{2 in the} direction of heat transfer to a recording material has at least two layers composed of a base layer and a release layer. A rotary heating member is disclosed that has a relationship of Rt <100 NT / V with (° C.), fixing speed V (mm / s), and nip width N (mm).
Patent Document 2 discloses a rotary heating member that generates heat by electromagnetic induction, “the thermal resistance value per cm ^{2 in the} direction of heat transfer to the recording material is 0.025 (° C./W) or more and 5 (° C./W)”. Is disclosed.

Japanese Patent Laid-Open No. 2003-084600 JP 2002-214946 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a fixing belt that is excellent in heating efficiency of a material to be fixed and is less likely to cause image quality defects due to pressure unevenness of the material to be fixed.

The above problems are solved by the present invention described below. That is,
The invention according to claim 1
A base material layer, a heat generating layer that generates heat by electromagnetic induction, two or more elastic layers, and a release layer are provided in this order,
The elastic layer closest to the heat generating layer has higher thermal conductivity than the other elastic layers, and the elastic layer closest to the release layer has a lower elastic modulus than the other elastic layers. , Fixing belt.

The invention according to claim 2
A heat transfer layer that is disposed between any two layers of the two or more elastic layers in contact with the elastic layer and has a higher thermal conductivity than the two elastic layers in contact with each other;
The fixing belt according to claim 1, further comprising:

The invention according to claim 3
The fixing belt according to claim 1 or 2,
A pressure member disposed in contact with the outer peripheral surface of the fixing belt;
An electromagnetic induction device for generating heat by electromagnetic induction in the heat generating layer provided in the fixing belt;
A fixing device provided with

The invention according to claim 4
A latent image carrier,
A charging device for charging the surface of the latent image holding member;
A latent image forming apparatus for forming a latent image on the surface of the latent image holding body;
A developing device for developing the latent image with toner to form a toner image;
A transfer device for transferring the toner image to a recording medium;
The fixing device according to claim 3, wherein the toner image is fixed on a recording medium.
An image forming apparatus.

  According to the invention of claim 1, the heating efficiency of the fixing material is excellent as compared with the case where the elastic layer is a single layer or the case where the thermal conductivity and the elastic modulus of the elastic layer of two or more layers are not related to each other. In addition, there is provided a fixing belt in which image quality defects caused by pressure unevenness of a fixing material are less likely to occur.

  According to the second aspect of the present invention, there is provided a fixing belt that is superior in heating efficiency of the fixing material as compared with the case where the heat transfer layer is not provided.

  According to the third and fourth aspects of the present invention, there are provided a fixing device and an image forming apparatus that are excellent in heating efficiency of a fixing material and are less likely to cause image quality defects due to pressure unevenness of the fixing material.

FIG. 3 is a schematic cross-sectional view illustrating an example of a fixing belt of the present embodiment. FIG. 6 is a schematic cross-sectional view showing another example of the fixing belt of the present embodiment. 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.

  Hereinafter, an exemplary embodiment of the present invention will be described.

<Fixing belt>
The fixing belt of the present embodiment includes a base material layer, a heat generating layer that generates heat by electromagnetic induction, two or more elastic layers, and a release layer in this order. The elastic layer closest to the heat generating layer has a higher thermal conductivity (W / m · K) than the other elastic layers, and the elastic layer closest to the release layer is the other elastic layer. The elastic modulus (GPa) is lower than that of the elastic layer.

The fixing belt according to the present exemplary embodiment is used as a fixing belt provided in an electromagnetic induction heating type fixing device in an electrophotographic image forming apparatus, for example.
For example, when the fixing belt of the present embodiment is applied to the fixing device, the fixing belt is excellent in heating efficiency of the material to be fixed and has image quality defects due to pressure unevenness of the material to be fixed. Hateful. The reason is not clear, but is presumed as follows.

An electromagnetic induction heating type fixing belt in an electrophotographic image forming apparatus is in contact with a fixing material such as toner on a recording medium to heat and press the fixing material, and the fixing material is used as a recording medium. Let it settle. As this fixing belt, a tubular body including a base material layer, a heat generating layer that generates heat by electromagnetic induction, an elastic layer, and a release layer in order from the inner peripheral side to the outer peripheral side is known.
In the fixing belt, the elastic layer imparts, for example, a follow-up property that closely follows the unevenness on the recording medium and a cushioning property in which a fixing material on the recording medium is embedded on the outer peripheral surface of the fixing belt. Then, it is considered that the outer peripheral surface of the fixing belt can press and crush the fixing material uniformly on the recording medium due to the followability and cushioning properties derived from the elasticity of the elastic layer.

  Incidentally, in the fixing belt, the elastic layer is required to have thermal conductivity from the viewpoint of efficiently transferring heat generated in the heat generating layer to the outer peripheral surface of the fixing belt. Thus, conventionally, there is a technique for increasing the thermal conductivity of the elastic layer by incorporating a filler such as a metal oxide, graphite, or heat transfer ceramics into the elastic layer. Generally, as the filler content is increased, the thermal conductivity of the elastic layer is improved and the fixing material can be heated more efficiently. Therefore, for example, the conveyance speed of the recording medium in the fixing device can be increased, and the length of the contact area (nip) between the fixing belt and the pressure member can be shortened to increase the fixing speed.

However, as the filler content of the elastic layer increases, the elastic modulus of the elastic layer tends to increase. Therefore, if the thermal conductivity of the elastic layer is increased by the filler, the followability and cushioning properties of the outer surface of the fixing belt are increased. Is easily damaged. As a result, unevenness occurs in pressing of the fixing material by the outer peripheral surface of the fixing belt, and the fixing material is crushed, specifically unevenness occurs, and this is caused by image quality defects such as image gloss unevenness, character collapse, especially color. This is thought to lead to the occurrence of image quality defects.
As described above, it is not easy to achieve both thermal conductivity and elasticity of the elastic layer. Therefore, it is possible to efficiently heat the fixing material and to suppress the occurrence of image quality defects due to pressure unevenness of the fixing material. It was not easy to achieve both.

  On the other hand, in the fixing belt of this embodiment, the elastic layer is divided into a plurality of layers, the thermal conductivity of the elastic layer closest to the heat generating layer is set higher than the thermal conductivity of the other elastic layers, and the release layer is formed. By making the elastic modulus of the closest elastic layer lower than the elastic modulus of the other elastic layers, the entire elastic layer can achieve both thermal conductivity and elasticity, and as a result, the heating efficiency of the fixing material is excellent. In addition, it is considered that image quality defects caused by uneven pressurization of the fixing material hardly occur.

The fixing belt of the present embodiment has two or more elastic layers, and may have three or more elastic layers. The fixing belt of the present embodiment has an elastic layer closest to the release layer by making the thermal conductivity of the elastic layer closest to the heat generating layer higher than that of the other elastic layers, regardless of the number of elastic layers. The elastic modulus of the layer is made lower than the elastic modulus of the other elastic layers.
The relationship between the thermal conductivity and the elastic modulus between the elastic layers is not limited to the above conditions, but it is desirable that the thermal conductivity of the plurality of elastic layers is higher as it is closer to the heating layer, and the elastic layer is closer to the release layer. A low rate is desirable.
In the fixing belt of the present embodiment, the number of elastic layers is preferably two in terms of both performance and manufacturing efficiency.

The fixing belt of the present embodiment is a heat transfer layer having a higher thermal conductivity than any of the two elastic layers in contact between the two elastic layers, in which both surfaces are in contact with the elastic layer. May be provided.
The fixing belt of the present embodiment includes the heat transfer layer, thereby improving the heat conduction efficiency to the surface of the release layer and improving the heating efficiency of the fixing material. As a result, the fixing speed of the fixing device is increased. It can be faster.
Further, since the fixing belt generally has a lower frequency of contact with the recording medium at the end in the width direction than at the center in the width direction, the surface temperature of the end becomes higher than the surface temperature of the center. A phenomenon (a phenomenon called “temperature rise at the edge”) may occur. On the other hand, when the fixing belt of the present embodiment includes the heat transfer layer, the temperature rise at the end portion hardly occurs. This is considered to be because the heat conduction efficiency in the surface direction from the end portion to the central portion is improved by the presence of the heat transfer layer.

  The fixing belt of the present embodiment may have a configuration in which another intermediate layer (for example, a protective layer) is provided between the base material layer and the heat generating layer or between the heat generating layer and the elastic layer closest to the heat generating layer. .

  The fixing belt of the present embodiment is configured in, for example, an endless tubular shape or a cylindrical shape also referred to as a “fixing roll”.

Hereinafter, the configuration of the fixing belt of this embodiment will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of the fixing belt of the present embodiment.
A fixing belt 10 shown in FIG. 1 includes a base material layer 11, a heat generating layer 12 disposed on the outer peripheral surface of the base material layer 11, an elastic layer 13A disposed on the outer peripheral surface of the heat generating layer 12, and an elastic layer. It has the elastic layer 13B arrange | positioned on the outer peripheral surface of 13A, and the mold release layer 14 arrange | positioned on the outer peripheral surface of the elastic layer 13B.
The elastic layer 13A has a higher thermal conductivity than the elastic layer 13B, and the elastic layer 13B has a lower elastic modulus than the elastic layer 13A.
The fixing belt 10 may further include one or more elastic layers between the elastic layer 13A and the elastic layer 13B. However, in this case, the thermal conductivity of the elastic layer 13A is higher than the thermal conductivity of the other elastic layers, and the elastic modulus of the elastic layer 13B is lower than the elastic modulus of the other elastic layers.

FIG. 2 is a schematic cross-sectional view showing another example of the fixing belt of the present embodiment.
The fixing belt 10 shown in FIG. 2 includes a base material layer 11, a heat generating layer 12 disposed on the outer peripheral surface of the base material layer 11, an elastic layer 13A disposed on the outer peripheral surface of the heat generating layer 12, and an elastic layer. The heat transfer layer 15 disposed on the outer peripheral surface of 13A, the elastic layer 13B disposed on the outer peripheral surface of the heat transfer layer 15, and the release layer 14 disposed on the outer peripheral surface of the elastic layer 13B. Have.
The elastic layer 13A has a higher thermal conductivity than the elastic layer 13B, the elastic layer 13B has a lower elastic modulus than the elastic layer 13A, and the heat transfer layer 15 has a higher thermal conductivity than the elastic layer 13A and the elastic layer 13B. The rate is high.
The fixing belt 10 may further include one or more elastic layers between the elastic layer 13A and the elastic layer 13B. However, in this case, the thermal conductivity of the elastic layer 13A is higher than the thermal conductivity of the other elastic layers, and the elastic modulus of the elastic layer 13B is lower than the elastic modulus of the other elastic layers. In this case, the heat transfer layer 15 is disposed between any two elastic layers so as to be in contact with both elastic layers, and has a higher thermal conductivity than both elastic layers in contact therewith.

Hereinafter, the raw materials and physical properties of each layer will be described.
In the following, “main component” means 50% or more by mass ratio.
The physical properties of each layer are measured by the following method.
The film thicknesses of the base material layer, the elastic layer, and the release layer are measured by an eddy current film thickness meter.
The film thickness of the heat generating layer is measured with a fluorescent X-ray film thickness meter.
The film thickness of the heat transfer layer is measured by either an eddy current film thickness meter or a fluorescent X-ray film thickness meter depending on the material of the layer.
The thermal conductivity (W / m · K) of the elastic layer and the heat transfer layer is measured by a temperature wave analysis method. Specifically, the layer is cut into 30 mm squares and measured using a thermal conductivity measuring machine (for example, ai-Phase Mobile manufactured by SII Nano Technology Co., Ltd.).
The elastic modulus (GPa) of the elastic layer is measured by a non-resonant forced vibration method. Specifically, the layer is cut into 4 mm × 20 mm and measured using a dynamic viscoelasticity measuring device (for example, Leo Vibron manufactured by A & D).

(Base material layer)
The base material layer 11 is composed of, for example, a resin as a main component. The resin preferably has heat resistance, such as polyimide, polyamide, polyamideimide, aromatic polyamide, fluororesin, thermotropic liquid crystal polymer, polyester, polyethylene terephthalate, polyethersulfone, polyetherketone, polysulfone, etc. Can be mentioned. Among these, polyimide is preferable.
The base material layer 11 may be a resin foam.
The base material layer 11 may contain a filler such as a metal oxide, graphite, or heat conductive ceramics.

  The thickness of the base material layer 11 is desirably 20 μm or more and 180 μm or less, and more desirably 20 μm or more and 80 μm or less.

  The base material layer 11 (for example, a polyimide layer) is formed, for example, by dip-coating a base material layer forming material on the outer peripheral surface of a core for manufacturing a fixing belt and baking it.

(Heat generation layer)
The heat generating layer 12 is a layer that generates heat due to, for example, an eddy current generated by a magnetic field, and is made of a metal that generates an electromagnetic induction effect.
Examples of the metal that generates electromagnetic induction include single metals (nickel, iron, copper, gold, silver, aluminum, chromium, tin, zinc, etc.) and alloys (steel, etc.). Among these, copper, nickel, aluminum, iron, and chromium are suitable, and copper or an alloy containing copper as a main component is particularly desirable.

  The appropriate thickness of the heat generating layer 12 varies depending on the material, but when it is made of copper, for example, it is preferably 3 μm to 50 μm, and more preferably 5 μm to 20 μm.

  The heat generating layer 12 is formed by a known method, for example, electroless plating, electrolytic plating, or electroforming on the outer peripheral surface of the base material layer 11.

(Protective layer)
The fixing belt 10 may include a protective layer (not shown) as necessary. The protective layer is a layer provided on the outer peripheral surface of the heat generating layer in order to suppress cracking or oxidation deterioration of the heat generating layer and maintain heat generation characteristics.

  The protective layer is composed of an oxidation resistant metal layer having high durability and oxidation resistance, for example. Specifically, for example, in consideration of workability with a thin film, an electrolytic plating layer is good, and among them, an electrolytic nickel plating layer which is a metal layer having high strength is good.

  The appropriate thickness of the protective layer varies depending on the material, but when it is made of, for example, nickel, it is preferably 2 μm or more and 20 μm or less.

(Elastic layer)
The fixing belt 10 includes an elastic layer 13A and an elastic layer 13B, and may further include one or more elastic layers between the elastic layer 13A and the elastic layer 13B. Hereinafter, each elastic layer is collectively referred to as an “elastic layer”.
In the present embodiment, the elastic layer is a layer made of an elastic material and having an elastic modulus of 5 × 10 ⁻³ GPa or less.

  The elastic material constituting the elastic layer is preferably a material that is excellent in heat resistance and can be restored to its original shape even when deformed by applying an external force of 100 Pa, for example. Examples of the elastic material include heat-resistant rubber such as silicone rubber and fluorine rubber. Specifically, liquid silicone rubber SE6744 (manufactured by Dow Corning Toray), Viton B-202 (DuPont Dow Elastmers) Manufactured) and the like.

  The elastic layer may contain fillers such as metal oxide, graphite, and heat transfer ceramics. In particular, the elastic layer 13A desirably contains a filler from the viewpoint of improving the thermal conductivity.

The thermal conductivity of the elastic layer 13A is preferably from 0.38 W / m · K to 0.84 W / m · K, more preferably from 0.38 W / m · K to 0.70 W / m · K.
When the thermal conductivity of the elastic layer 13A is 0.38 W / m · K or more, the heat generated in the heat generating layer 12 is efficiently conducted from the heat generating layer 12 to the elastic layer 13A. Then, heat is efficiently conducted to the outer peripheral surface of the fixing belt 10 and the heating efficiency of the fixing material is improved. As a result, the fixing speed of the fixing device including the fixing belt 10 can be increased.
From the viewpoint of ensuring the elasticity of the elastic layer 13A, it is desirable that the filler content is not too large. Therefore, the thermal conductivity is 0.84 W / m · K or less (more preferably 0.70 W / m · K or less). ) Is appropriate.

  The thermal conductivity of the elastic layer other than the elastic layer 13A is preferably 0.38 W / m · K or more and 0.70 W / m · K or less from the viewpoint of ensuring the thermal conductivity and elasticity of the entire elastic layer.

The elastic modulus of the elastic layer 13 </ b> B is desirably 0.5 × 10 ⁻³ GPa or more and 5 × 10 ⁻³ GPa or less from the viewpoint of imparting appropriate followability and cushioning properties to the outer peripheral surface of the fixing belt 10. More preferably, it is not less than × 10 ⁻³ GPa and not more than 1.5 × 10 ⁻³ GPa.

The elastic modulus of the elastic layer other than the elastic layer 13B is preferably 0.5 × 10 ⁻³ GPa or more and 5 × 10 ⁻³ GPa or less from the viewpoint of ensuring the flexibility of the entire elastic layer, and 0.7 × 10 ^−3. More preferably, the pressure is from 5 Pa to 5 × 10 ⁻³ GPa.

  The thickness of the elastic layer 13B is desirably 50 μm or more and 300 μm or less, and more desirably 50 μm or more and 150 μm or less, from the viewpoint of imparting appropriate followability and cushioning properties to the outer peripheral surface of the fixing belt 10.

The thickness of the elastic layer 13A is preferably 50 μm or more and 300 μm or less, and more preferably 50 μm or more and 200 μm or less, from the viewpoint of ensuring the flexibility of the entire elastic layer and the heat capacity of the fixing belt.
When there is one or more elastic layers between the elastic layer 13A and the elastic layer 13B, the thickness of each layer is desirably 20 μm or more and 150 μm or less, and more desirably 50 μm or more and 100 μm or less.
The thickness of the entire elastic layer is preferably 0.1 mm or more and 3 mm or less, and more preferably 0.15 mm or more and 0.5 mm or less from the viewpoint of ensuring the flexibility of the entire elastic layer and the heat capacity of the fixing belt. .

  The elastic layer is formed, for example, by immersing and baking an elastic material such as liquid silicone rubber (which may contain a filler as necessary) for each elastic layer and baking.

(Heat transfer layer)
The fixing belt 10 may include a heat transfer layer 15 as necessary. The heat transfer layer 15 is disposed between the elastic layer and the elastic layer. The heat transfer layer 15 is a layer having higher thermal conductivity than both elastic layers in contact with each other, from the viewpoint of providing the layer and improving the efficiency of heat conduction.

  Specifically, the thermal conductivity of the heat transfer layer 15 is desirably 0.84 W / m · K or more. When the thermal conductivity of the heat transfer layer 15 is 0.84 W / m · K or more, the heat conduction efficiency to the outer peripheral surface side of the fixing belt 10 is improved, and the heating efficiency of the fixing material is improved. The fixing speed of the fixing device can be further increased. Further, it is possible to suppress the occurrence of the temperature rise at the end of the fixing belt 10.

  The heat transfer layer 15 includes, for example, a metal sheet or film; a material in which an elastic material such as silicone rubber is mixed with a filler such as metal oxide, graphite, or heat transfer ceramics.

  The thickness of the heat transfer layer 15 is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 20 μm or less.

  The heat transfer layer 15 (for example, a metal film) is provided on the elastic layer on the inner peripheral side by using a heat transfer layer film and using, for example, an adhesive.

(Release layer)
The release layer 14 prevents the fixing material such as toner from being fixed to the fixing belt 10.
The release layer 14 is composed of, for example, a fluorine compound as a main component. Examples of the fluorine compound include fluorine resins such as fluorine rubber, polytetrafluoroethylene (PTFE), perfluoroalkyl vinyl ether copolymer (PFA), and tetrafluoroethylene hexafluoropropylene copolymer (FEP). It is done.

  The thickness of the release layer 14 is preferably 1 μm to 100 μm, and more preferably 10 μm to 50 μm.

  The release layer 14 is formed, for example, by preparing a release layer tube (PFA tube or the like), inserting a government body provided with an elastic layer 13B into the tube, and performing firing as necessary. The You may apply | coat an adhesive agent to the surface of the elastic layer 13B as needed.

<Fixing device>
FIG. 3 is a schematic configuration diagram illustrating an example of the fixing device of the present embodiment.
A fixing device 100 shown in FIG. 3 is an electromagnetic induction heating type fixing device including the fixing belt 10 of the present embodiment, a pressure roll 20 (an example of a pressure member), and an electromagnetic induction device 40.

The pressure roll 20 is disposed in contact with the outer peripheral surface of the fixing belt 10, and a contact region (nip) is formed between the fixing belt 10 and the pressure roll 20.
The pressure roll 20 includes a base material layer 21, an elastic layer 22, and a release layer 23. The base material layer 21 is a layer containing, for example, a resin as a main component. The elastic layer 22 is a layer of an elastic body such as silicone rubber. The release layer 23 is a layer containing, for example, a fluororesin as a main component.

  A facing member 30 is disposed inside the fixing belt 10 at a position facing the pressure roll 20. The facing member 30 includes a pad 32 that is in contact with the inner peripheral surface of the fixing belt 10 and locally increases the pressure, and a support body 31 that supports the pad 32. The pad 32 is a member made of, for example, metal, heat resistant resin, heat resistant rubber or the like.

The electromagnetic induction device 40 is disposed at a position facing the pressure roll 20 with the fixing belt 10 interposed therebetween, and causes the heat generation layer 12 of the fixing belt 10 to generate heat by electromagnetic induction.
The electromagnetic induction device 40 incorporates an electromagnetic induction coil (excitation coil) 41. The electromagnetic induction device 40 applies an alternating current to the electromagnetic induction coil 41 to generate a magnetic field, changes this magnetic field with an excitation circuit, and generates an eddy current in the heat generating layer 12 of the fixing belt 10. This eddy current is converted into heat (Joule heat) by the electric resistance of the heat generating layer 12, and the surface of the fixing belt 10 generates heat.

  The arrangement position of the electromagnetic induction device 40 is not limited to the position shown in FIG. 3. For example, the electromagnetic induction device 40 is arranged on the upstream side in the rotation direction (the direction of arrow B) with respect to the contact area between the fixing belt 10 and the pressure roll 20. It may be arranged inside the fixing belt 10.

In the fixing device 100, a driving force is transmitted to gears (not shown) arranged at both ends of the fixing belt 10 by a driving device (not shown), the fixing belt 10 rotates in the direction of arrow B, and the fixing belt 10 rotates. Accordingly, the pressure roll 20 rotates in the direction of arrow C.
The recording medium P on which the unfixed toner image T is formed is conveyed in the direction of the arrow A and passes through the contact area between the fixing belt 10 and the pressure roll 20. At this time, the unfixed toner image T is fixed to the recording medium P by being heated and pressurized.

<Image forming apparatus>
FIG. 4 is a schematic configuration diagram illustrating an example of the image forming apparatus according to the present exemplary embodiment.
4 includes a photosensitive member 202 (an example of a latent image holding member), a charging device 204, a laser exposure device 206 (an example of a latent image forming device), a mirror 208, a developing device 210, and an intermediate transfer member 212. , A transfer roll 214 (an example of a transfer device), a cleaning device 216, a static eliminator 218, the fixing device 100 of this embodiment, and a paper feed device (paper feed unit 220, paper feed roller 222, registration roller 224, and recording medium guide) 226).

  The charging device 204 is a non-contact type charging device provided in the vicinity of the photoconductor 202 and charges the surface of the photoconductor 202.

  The laser exposure device 206 irradiates the surface of the charged photoconductor 202 with a laser beam corresponding to the image information (signal) via the mirror 208 to form a latent image on the surface of the photoconductor 202.

The developing device 210 includes a developing device (not shown) that stores toner of each color (for example, cyan, magenta, yellow, and black).
The developing device 210 applies toner to the latent image on the surface of the photoconductor 202 while rotating in the direction of the arrow, and forms a toner image on the surface of the photoconductor 202.

The intermediate transfer member 212 is disposed in contact with the surface of the photosensitive member 202. For example, a toner image is transferred from the photosensitive member 202 by a bias voltage applied between the photosensitive member 202 and the intermediate transfer member 212. The
The transfer roll 214 is disposed in contact with the outer peripheral surface of the intermediate transfer body 212, and the toner image is transferred to the conveyed recording medium P at this contact portion.

  The fixing device 100 fixes the toner image T to the recording medium P as described above.

The cleaning device 216 removes the toner remaining on the surface of the photoconductor 202 after the toner image is transferred to the intermediate transfer body 212.
The neutralization device 218 neutralizes the surface of the photoconductor 202 after the residual toner is removed by the cleaning device 216.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.
Unless otherwise specified, “part” means “part by mass”.

<Example 1>
(Formation of base material layer)
A coating solution obtained by diluting polyamic acid with an N-methylpyrrolidone solution (Unitika, Uimide, concentration 20% by mass) is dip-coated on the outer peripheral surface of the core for manufacturing a fixing belt, and baked at 360 ° C. for 1 hour. A base material layer (polyimide layer) having a thickness of 30 μm was formed.

(Formation of heat generation layer)
An electroless plating process is performed on the surface of the base material layer to form a conductive layer (Ni layer) having a thickness of 0.5 μm, and then an electroplating process is performed to form a heat generating layer (Cu layer) having a thickness of 15 μm. Formed.

(Formation of elastic layer A)
On the surface of the heat generating layer, a filler-containing rubber material in which 100 parts of alumina is mixed with 100 parts of liquid silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., LIM material) is dip coated, and baked and cured at 120 ° C. for 10 minutes to obtain a thickness. An elastic layer A having a thickness of 150 μm was formed.

(Formation of elastic layer B)
Liquid silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., LIM material) was dip-coated on the surface of the elastic layer A, and baked and cured at 120 ° C. for 10 minutes to form an elastic layer B having a thickness of 50 μm.

(Formation of release layer)
On the surface of the elastic layer B, a silane coupling agent adhesive (manufactured by Toray Dow Corning Silicone) was applied and dried by heating at 150 ° C. for 10 minutes. The laminate with the adhesive on the outermost surface is inserted into the expanded PFA tube (30 μm, Kurashiki Boseki Co., Ltd.) together with the production core, covered with the PFA tube, and baked at 200 ° C. for 4 hours. A release layer was formed.
And the laminated body was removed from the core for manufacture, the unnecessary part of both ends was cut, and the fixing belt (1) was obtained. Table 1 shows the thermal conductivity and elastic modulus of the elastic layer A and elastic layer B.

<Example 2>
In the same manner as in Example 1, a base material layer, a conductive layer, and a heat generating layer were formed.

(Formation of elastic layer A)
On the surface of the heat generating layer, a filler-containing rubber material in which 150 parts of alumina is mixed with 100 parts of liquid silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., LIM material) is dip coated, and baked and cured at 120 ° C. for 10 minutes to obtain a thickness. An elastic layer A having a thickness of 150 μm was formed.

  Thereafter, an elastic layer B and a release layer were formed in the same manner as in Example 1 to obtain a fixing belt (2). Table 1 shows the thermal conductivity and elastic modulus of the elastic layer A and elastic layer B.

<Example 3>
In the same manner as in Example 1, a base material layer, a conductive layer, and a heat generating layer were formed.

(Formation of elastic layer A)
On the surface of the heat generating layer, a filler-containing rubber material in which 50 parts of alumina is mixed with 100 parts of liquid silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., LIM material) is dip-coated, fired and cured at 120 ° C. for 10 minutes, thickness An elastic layer A having a thickness of 150 μm was formed.

  Thereafter, an elastic layer B and a release layer were formed in the same manner as in Example 1 to obtain a fixing belt (3). Table 1 shows the thermal conductivity and elastic modulus of the elastic layer A and elastic layer B.

<Example 4>
In the same manner as in Example 1, a base material layer, a conductive layer, a heat generating layer, and an elastic layer A were formed.

(Formation of elastic layer B)
The elastic layer B was formed in the same manner as in Example 1, except that the thickness was changed to 10 μm.

  Thereafter, a release layer was formed in the same manner as in Example 1 to obtain a fixing belt (4). Table 1 shows the thermal conductivity and elastic modulus of the elastic layer A and elastic layer B.

<Example 5>
In the same manner as in Example 1, a base material layer, a conductive layer, a heat generating layer, and an elastic layer A were formed.

(Formation of heat transfer layer)
A silane coupling agent adhesive (made by Toray Dow Corning Silicone) is applied to the surface of the elastic layer A, and a metal film for heat transfer layer (thickness 10 μm) is placed and pressed to form a heat transfer layer. did.

  Thereafter, an elastic layer B and a release layer were formed in the same manner as in Example 1 to obtain a fixing belt (5). Table 1 shows the thermal conductivity and elastic modulus of the elastic layer A and elastic layer B, and the thermal conductivity of the heat transfer layer.

<Comparative Example 1>
In the same manner as in Example 1, a base material layer, a conductive layer, and a heat generating layer were formed.

(Formation of elastic layer D)
A filler-containing rubber material in which 100 parts of boron nitride is blended in 100 parts of liquid silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., LIM material) is dip-coated on the surface of the heat generating layer, cured by baking at 120 ° C. for 10 minutes, An elastic layer D having a thickness of 200 μm was formed.

  Thereafter, a release layer was formed in the same manner as in Example 1 to obtain a fixing belt (C1). Table 1 shows the thermal conductivity and elastic modulus of the elastic layer C.

<Comparative example 2>
In the same manner as in Example 1, a base material layer, a conductive layer, and a heat generating layer were formed.

(Formation of elastic layer A)
Liquid silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., LIM material) was dip-coated on the surface of the heat generating layer and baked and cured at 120 ° C. for 10 minutes to form an elastic layer A having a thickness of 150 μm.

(Formation of elastic layer B)
On the surface of the elastic layer A, a material in which 30 parts of alumina is mixed with 100 parts of liquid silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., LIM material) is dip-coated, baked and cured at 120 ° C. for 10 minutes, and a thickness of 50 μm Elastic layer B was formed.

  Thereafter, a release layer was formed in the same manner as in Example 1 to obtain a fixing belt (C2). Table 1 shows the thermal conductivity and elastic modulus of the elastic layer A and elastic layer B.

<Evaluation>
Each of the fixing belts of Examples and Comparative Examples was mounted as a fixing belt in an electromagnetic induction heating type fixing device provided in an electrophotographic image forming apparatus (manufactured by Fuji Xerox Co., Ltd., DocuCenter IV5575).
Using this image forming apparatus, C2 paper (A4 size) manufactured by Fuji Xerox Co., Ltd. is used, under a temperature of 22 ° C./humidity of 55% RH, four colors (cyan, magenta, yellow, black) and a density of 100% black solid. Formed. The fixing speed was 50 sheets / minute.

(image quality)
The gloss unevenness of the 100th image was evaluated according to the following criteria. The results are shown in Table 1.
A: Uneven gloss was not observed.
B +: A slight unevenness in gloss was observed, but it was not a problem for practical use.
B: Although uneven gloss was observed, it was within a practically acceptable range.
B-: Uneven gloss was observed, which was a practically acceptable limit.
C: Uneven gloss was clearly observed, and the practically acceptable limit was not reached.

(End temperature rise)
Immediately after 100 images were formed, the temperature of the outer peripheral surface of the fixing belt was measured using a non-contact thermometer (manufactured by Keyence Corporation, infrared radiation thermometer).
-End of fixing belt: Measurement was performed by rotating a member at a position 20 mm from both ends of the fixing belt.
-Center portion of fixing belt: Measurement was performed by rotating the member at the center position from both ends of the fixing belt.
Then, the difference between the average temperature at the end and the average temperature at the center (average temperature at the end-average temperature at the center) was determined. The results are shown in Table 1.

  As can be seen from Table 1, in the example, the occurrence of image quality defects was suppressed as compared with the comparative example.

DESCRIPTION OF SYMBOLS 10 Fixing belt 11 Base material layer 12 Heat generation layer 13A Elastic layer 13B Elastic layer 14 Release layer 15 Heat transfer layer

T toner image P recording medium 20 pressure roll 21 base layer 22 elastic layer 23 release layer 30 opposing member 31 support 32 pad 40 electromagnetic induction device 41 electromagnetic induction coil

DESCRIPTION OF SYMBOLS 100 Fixing apparatus 200 Image forming apparatus 202 Photoconductor 204 Charging apparatus 206 Laser exposure apparatus 208 Mirror 210 Development apparatus 212 Intermediate transfer body 214 Transfer roll 216 Cleaning apparatus 218 Static elimination apparatus

Claims (4)

A base material layer, a heat generating layer that generates heat by electromagnetic induction, two or more elastic layers, and a release layer are provided in this order,
The elastic layer closest to the heat generating layer has higher thermal conductivity than the other elastic layers, and the elastic layer closest to the release layer has a lower elastic modulus than the other elastic layers. , Fixing belt. A heat transfer layer that is disposed between any two layers of the two or more elastic layers in contact with the elastic layer and has a higher thermal conductivity than the two elastic layers in contact with each other;
The fixing belt according to claim 1, further comprising: The fixing belt according to claim 1 or 2,
A pressure member disposed in contact with the outer peripheral surface of the fixing belt;
An electromagnetic induction device for generating heat by electromagnetic induction in the heat generating layer provided in the fixing belt;
A fixing device provided with A latent image carrier,
A charging device for charging the surface of the latent image holding member;
A latent image forming apparatus for forming a latent image on the surface of the latent image holding body;
A developing device for developing the latent image with toner to form a toner image;
A transfer device for transferring the toner image to a recording medium;
The fixing device according to claim 3, wherein the toner image is fixed on a recording medium.
An image forming apparatus.