JP2013037297A - Fixing member, fixing device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing member that suppresses deterioration of an elastic layer due to infrared heating.SOLUTION: A fixing member includes at least a substrate 200, an elastic layer 210, an infrared reflection layer 220, and a surface layer 230 in this order.

Description

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

In an image forming apparatus such as a copying machine or a printer using an electrophotographic system, a toner image formed on a recording sheet is fixed by a fixing device to form an image.
As a fixing member used in the fixing device, a structure in which an elastic layer and a surface layer are laminated in this order on a substrate is generally employed, and an adhesive layer is provided between the layers as necessary.

  For example, in order to provide a heat fixing device that is excellent in durability and thermal efficiency in a heating method in which a fixing member is heated by contact from the outside, an unfixed image carried on a recording material is formed by a fixing member and a pressure member. In the heat fixing apparatus for heat fixing by passing through the fixing nip, the heating means for heating the surface of the fixing member from the outside is a carbon heater, and the carbon heater is in contact with the fixing member. (For example, see Patent Document 1).

JP 2010-266702 A

  An object of the present invention is to provide a fixing member in which deterioration of an elastic layer due to infrared heating is suppressed.

That is, the invention according to claim 1
The fixing member includes at least a base, an elastic layer, an infrared reflecting layer, and a surface layer in this order.

The invention according to claim 2
2. The fixing member according to claim 1, further comprising a heat insulating layer between the infrared reflecting layer and the surface layer.

The invention according to claim 3
The fixing member according to claim 1, wherein the infrared reflecting layer is a heat-resistant elastomer containing at least an infrared reflecting agent.

The invention according to claim 4
The fixing member according to claim 3, wherein the infrared reflective agent is a plate-like particle.

The invention according to claim 5
The fixing member according to claim 2, wherein the heat insulating layer is a foamed fluororesin.

The invention according to claim 6
The fixing member according to any one of claims 1 to 5, wherein the surface layer is a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer containing an infrared absorption accelerator.

The invention according to claim 7 provides:
The fixing member according to claim 6, wherein the infrared absorption accelerator is polytetrafluoroethylene particles or carbon.

The invention according to claim 8 provides:
The fixing member according to any one of claims 1 to 7, which is supported so as to be capable of circulating movement,
Driving means for circulatingly driving the fixing member;
A pressure roll pressed against the fixing member and sandwiching a recording medium with the fixing member;
Fixing heating means for heating the fixing member;
Infrared heating means for heating the surface layer to be higher than the temperature heated by the fixing heating means by irradiating infrared rays from the surface layer side of the fixing member;
A fixing device.

The invention according to claim 9 is:
An image carrier,
Charging means for charging the surface of the image carrier;
Latent image forming means for forming a latent image on the surface of the charged image carrier;
Developing means for developing the latent image with toner to form a toner image;
Transfer means for transferring the toner image to a recording medium;
Fixing means for fixing the toner image to the recording medium, the fixing means being the fixing device according to claim 8;
An image forming apparatus.

  According to the first aspect of the present invention, as compared with the case where the base, the elastic layer, the infrared reflecting layer, and the surface layer are not provided in this order, by infrared heating when infrared rays are irradiated from the surface layer side. A fixing member in which deterioration of the elastic layer is suppressed is provided.

  According to the invention of claim 2, the elastic layer by infrared heating when the infrared ray is irradiated from the surface layer side, compared with the case where the heat insulating layer is not provided between the infrared reflective layer and the surface layer, and A fixing member in which deterioration of the infrared reflecting layer is suppressed is provided.

  According to the invention of claim 3, defects such as cracks are generated in the infrared reflective layer when a strain stress is generated, as compared with a case where the infrared reflective layer is not a heat-resistant elastomer containing at least an infrared reflective agent. There is provided a fixing member in which this is suppressed.

  According to the fourth aspect of the present invention, there is provided a fixing member in which an increase in the temperature of the infrared reflecting layer is suppressed when infrared rays are irradiated from the surface layer side as compared with the case where the infrared reflecting agent is not a plate-like particle. The

  According to the invention which concerns on Claim 5, compared with the case where a heat insulation layer is not a foaming fluororesin, when the infrared rays are irradiated from the surface layer side, reduction of the thermal deterioration of the layer which exists in the base | substrate side rather than the heat insulation layer is reduced. A possible fuser member is provided.

  According to the invention according to claim 6, the surface when the surface layer is irradiated with infrared rays from the surface layer side as compared with the case where the surface layer is not a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer containing an infrared absorption accelerator. There is provided a fixing member capable of reducing thermal deterioration of a layer existing on the base side of the layer.

  According to the seventh aspect of the invention, there is provided a fixing member capable of improving the infrared absorption rate of the surface layer as compared with the case where the infrared absorption accelerator is not polytetrafluoroethylene particles or carbon.

  According to the eighth aspect of the present invention, there is provided a fixing device capable of removing wrinkles generated on the surface of the fixing member as compared with the case where this configuration is not provided.

  According to the ninth aspect of the present invention, there is provided an image forming apparatus capable of removing wrinkles generated on the surface of the fixing member as compared with the case where the present configuration is not provided.

It is a sectional view showing an example of a fixing member of this embodiment. It is sectional drawing which shows another example of the fixing member of this 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 a configuration of an image forming apparatus according to an exemplary embodiment.

  Hereinafter, embodiments of a fixing member, a fixing device, and an image forming apparatus of the present invention will be described in detail.

<Fixing member>
The fixing member of the present embodiment includes at least a base, an elastic layer, an infrared reflecting layer, and a surface layer in this order.
The fixing member of this embodiment may be configured as an endless fixing belt.

  Strain stress is applied to the surface layer of the fixing member at the sheet peeling portion or pressure contact portion of the fixing device, or the contact portion between the small diameter roll, the surface layer refresh roll or the surface layer heating roll of the fixing device and the surface layer of the fixing member. Is done. As a result, there may be a problem that wrinkles are generated on the surface layer of the fixing member.

  To solve this problem, development of a surface layer that suppresses generation of wrinkles as an approach from materials and design of a fixing device within a range that does not generate wrinkles as an approach from a system are performed. However, in order to meet the recent demand for higher image quality at higher speeds, a further increase in the load on the surface layer of the fixing member is inevitable, and it has become difficult to suppress the occurrence of wrinkles on the surface layer. .

  On the other hand, the present inventor has intensively studied a method for smoothly recovering the surface layer in which wrinkles are generated (takes the surface layer wrinkles), and heating the surface layer to a temperature higher than the fixing temperature results in the surface layer wrinkling. It was found that it is possible to take.

  In order to remove the wrinkles of the surface layer, it is preferable to heat the surface layer to a high temperature of 230 ° C. or higher. Although heat transfer heating by heat roll contact is generally used for heating the surface layer, in this case, even when heating is performed from the surface layer side (outside of the fixing member), heat transfer from the surface layer to the elastic layer is performed. Heating to about 230 ° C. may cause problems such as delamination and deterioration of the elastic layer.

Radiation heating by infrared irradiation from the surface layer side of the fixing member has also been attempted, but the elastic layer is also heated by the infrared light transmitted through the surface layer, which may cause problems such as delamination and thermal degradation of the elastic layer. there were. This was an inevitable problem for the following reasons.
That is, in order to obtain a good fixed image, the surface layer needs to be thinned to about 40 μm or less, but the thinned surface layer cannot completely absorb infrared rays. Furthermore, when the surface layer is made of fluororesin and the elastic layer is made of silicone rubber, the infrared absorption wavelength region of the surface layer fluororesin overlaps with the infrared absorption wavelength region of the elastic layer silicone rubber. If the layer fluororesin is heated by infrared rays, even the elastic layer silicone rubber is heated by infrared rays.

  In the present embodiment, an infrared reflection layer is provided between the surface layer and the elastic layer. The fixing member according to this embodiment has such a configuration, and when the surface layer is heated to irradiate infrared rays from the surface layer side of the fixing member to take a surface layer soot, the infrared rays transmitted through the surface layer are transmitted. Is reflected by the infrared reflecting layer and does not transfer heat to the elastic layer side, so that deterioration of the elastic layer due to infrared heating is suppressed.

Hereinafter, the fixing member of this embodiment will be described with reference to the drawings. In addition, in this embodiment, the same code | symbol is provided to the member which has the same function through all the drawings, and the description may be abbreviate | omitted.
FIG. 1 is a cross-sectional view showing an endless fixing belt 84 which is an example of a fixing member of the present embodiment. As shown in FIG. 1, the fixing belt 84 is provided with an elastic layer 210, an infrared reflecting layer 220, and a surface layer 230 in this order on a substrate 200.

  The substrate 200 is required to have heat resistance and mechanical strength, and a metal sheet such as nickel, aluminum or stainless steel, or a resin film such as polyimide, polyamideimide, polyphenylene sulfide, polyetheretherketone or polybenzimidazole may be used. it can. The resin may have a volume resistivity controlled by adding and dispersing conductive powder or the like. Specifically, for example, an endless belt-shaped polyimide belt in which volume resistivity is controlled by adding and dispersing carbon black can be used as the substrate 200. Furthermore, the base body 200 can be used by combining both end portions of a long polyimide sheet on a puzzle, thermocompression bonding using a thermocompression bonding member, and making an endless belt shape.

  The thickness of the substrate 200 is preferably in the range of 20 μm to 200 μm, more preferably in the range of 30 μm to 150 μm, and still more preferably in the range of 40 μm to 130 μm. When the thickness of the substrate 200 is 20 μm or more, the requirements for dimensional stability during heating and cooling and strength can be satisfied. On the other hand, if it is 200 μm or less, the specific heat of the fixing member is reduced and the amount of heat transfer is increased, leading to an improvement in transfer speed and cycle time.

  For the elastic layer 210, it is preferable to use silicone rubber, fluorine rubber or the like excellent in heat resistance, and it is particularly preferable to use silicone rubber. Examples of the silicone rubber include RTV silicone rubber, HTV silicone rubber, and liquid silicone rubber. Specifically, polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methyl phenyl silicone rubber (PMQ). ), Fluorosilicone rubber (FVMQ) and the like. Further, as the fluororubber, vinylidene fluoride rubber, tetrafluoroethylene / propylene rubber, tetrafluoroethylene / perfluoromethyl vinyl ether rubber, phosphazene rubber, fluoropolyether, and other fluororubbers can be used.

  Various additives may be blended in the elastic layer 210. Examples of additives include reinforcing agents (carbon black, etc.), fillers (calcium carbonate, etc.), softeners (paraffins, etc.), processing aids (stearic acid, etc.), anti-aging agents (amines, etc.), additives Examples include sulfurizing agents (sulfur, metal oxides, peroxides, etc.), functional fillers (alumina, etc.), and the like.

  The thickness of the elastic layer 210 is preferably in the range of 30 μm to 500 μm, and more preferably in the range of 100 μm to 300 μm.

The infrared reflecting layer 220 is required to have the ability to reflect infrared rays irradiated from the surface layer 230 side, and may be made of, for example, a metal or an organic material containing an infrared reflecting agent.
Examples of the metal constituting the infrared reflective layer 220 include nickel, aluminum, stainless steel, gold, silver, copper, platinum, rhodium, and titanium.
When the infrared reflective layer 220 is made of metal, the thickness of the infrared reflective layer 220 is preferably in the range of 1 μm to 100 μm, and more preferably in the range of 3 μm to 30 μm.

As the organic material constituting the infrared reflective layer 220, for example, the above-described silicone rubber, fluorine rubber, ethylene propylene rubber, acrylic rubber, butyl rubber, or the like may be used, but an organic material having excellent heat resistance is preferable. More preferably, a heat resistant elastomer is used. Specific examples of the heat resistant elastomer include, for example, silicone rubber, fluororubber and the like.
If the infrared reflective layer 220 is made of a heat-resistant elastomer containing an infrared reflective agent, the infrared reflective layer 220 can be given more flexibility than the case where the infrared reflective layer 220 is made of metal. It is possible to suppress the occurrence of defects such as cracks in the infrared reflective layer 220 when a strain stress load occurs.

Examples of the infrared reflecting agent constituting the infrared reflecting layer 220 include plate-like particles, spherical particles, amorphous particles, columnar particles, acicular particles, dendritic particles, and the like. Among these, since the infrared reflecting agent is plate-shaped, the infrared reflection in the infrared reflecting layer 220 is inhibited from being reflected a plurality of times, the infrared absorption rate can be kept low, and the temperature rise of the infrared reflecting layer 220 can be suppressed. Therefore, it is preferable to use plate-like particles.
In the present embodiment, the plate-like particles refer to particles having a flat plate shape, a hexagon plate shape, a scale plate shape, or the like.
The volume average particle diameter of the plate-like particles is preferably in the range of 0.5 μm to 30 μm, and more preferably in the range of 2 μm to 20 μm. The aspect ratio of the plate-like particles is preferably in the range of 2 to 25, more preferably in the range of 3 to 20.
In the present embodiment, the plate surface diameter / thickness of the particles measured by observation with an electron microscope is referred to as an aspect ratio.
Examples of components constituting the plate-like particles include silica, calcium carbonate, various metals, metal oxides, and the like.
2 mass% or more and 50 mass% or less are preferable, and, as for content of the infrared reflective agent in the infrared reflective layer 220, 5 mass% or more and 30 mass% or less are more preferable.

  The thickness of the infrared reflective layer 220 when the infrared reflective layer 220 is composed of an organic material containing an infrared reflective agent is preferably in the range of 3 μm to 300 μm, and more preferably in the range of 10 μm to 150 μm.

  Since the surface layer 230 is required to have toner releasability and heat resistance, for example, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexa Use fluororesin such as fluoropropylene copolymer (FEP), polyethylene / tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychloroethylene trifluoride (PCTFE), vinyl fluoride (PVF), etc. Can do.

The surface layer 230 may contain an infrared absorption accelerator for improving the infrared absorption rate. Specific examples of the infrared absorption accelerator include polytetrafluoroethylene particles, carbon, silica, various metal particles, metal oxide particles, and the like. Among these, polytetrafluoroethylene particles or carbon are used. Can be mentioned.
2 mass% or more and 60 mass% or less are preferable, and, as for content of the infrared absorption promoter in the surface layer 230, 5 mass% or more and 40 mass% or less are more preferable.

In the present embodiment, the surface layer 230 is more preferably a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer containing an infrared absorption accelerator, and polytetrafluoroethylene particles or carbon is used as the infrared absorption accelerator. The tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer is particularly preferable.
Use of a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer improves heat resistance and toner releasability. Moreover, since the infrared absorption rate of the surface layer 230 is increased by using the infrared absorption accelerator, the infrared absorption rate to the layer existing on the substrate 200 side than the surface layer 230 can be reduced. It becomes possible to prevent thermal degradation of the layer existing on the substrate 200 side.
Furthermore, by using polytetrafluoroethylene particles or carbon as an infrared absorption accelerator, it is possible to improve the infrared transmittance while minimizing the decrease in toner releasability and mechanical properties of the surface layer 230. Become.

  The thickness of the surface layer 230 is preferably 10 μm or more and 50 μm or less, and more preferably 20 μm or more and 45 μm or less in terms of workability and fixability.

  Further, in the fixing belt 84, other layers such as an adhesive layer may be formed between the base body 200 and the elastic layer 210, the elastic layer 210 and the infrared reflective layer 220, and the infrared reflective layer 220 and the surface layer 230.

  FIG. 2 is a cross-sectional view showing an endless fixing belt 84 ′ which is another example of the fixing member of the present embodiment. As shown in FIG. 2, the fixing belt 84 ′ is provided with an elastic layer 210, an infrared reflective layer 220, a heat insulating layer 240, and a surface layer 230 in this order on a base 200.

  Constituent materials, layer thicknesses, preferred modes, and the like of the base body 200, the elastic layer 210, the infrared reflective layer 220, and the surface layer 230 in the fixing belt 84 'are the same as those of the fixing belt 84.

  The heat insulation layer 240 is required to have an ability to suppress heat conduction to the base 200 side. By providing the heat insulating layer 240 between the surface layer 230 and the infrared reflective layer 220, the infrared reflective layer 220 is prevented from being heated to a high temperature when irradiated with infrared rays from the surface layer 230 side. Deterioration of the elastic layer 210 and the infrared reflective layer 220 is suppressed.

  The thermal conductivity of the heat insulating layer 240 is, for example, preferably 0.3 W / (m · K) or less, and more preferably 0.1 W / (m · K) or less.

  Examples of the material constituting the heat insulating layer 240 include foamed fluororesin, fluororesin, foamed silicone rubber, silicone rubber, and fluororubber. Among these, it is preferable to use a foamed fluororesin. Since the foamable fluororesin has excellent heat resistance and contains a large number of bubbles in the fluororesin, it scatters and absorbs infrared rays. Therefore, when the infrared rays are irradiated from the surface layer 230 side, the substrate 200 is more than the heat insulating layer 240. The infrared transmittance to the side can be reduced, and as a result, it is possible to prevent thermal degradation of the layer existing on the base 200 side with respect to the heat insulating layer 240.

Examples of the fluororesin constituting the foamed fluororesin include the fluororesins exemplified in the surface layer 230.
The method of foaming the fluororesin is not particularly limited, but a method of extruding a fluororesin copolymer pellet mixed with a foam nucleating agent or a fluororesin coating solution containing a foaming agent is applied. And a foaming method.

  The thickness of the heat insulation layer 240 is preferably 10 μm or more and 500 μm or less, and more preferably 20 μm or more and 300 μm or less in terms of heat insulation and hardness.

<Fixing device>
The fixing device of the present embodiment includes a fixing member of the present embodiment that is supported so as to be circulated, a driving unit that circulates and drives the fixing member, and a recording medium that is pressed against the fixing member and between the fixing member. A pressure roll that sandwiches the fixing member, a heating means for fixing that heats the fixing member, and a temperature higher than the temperature at which the surface layer is heated by the heating means for fixing by irradiating infrared rays from the surface layer side of the fixing member. Infrared heating means for heating to a high temperature. The fixing member is disposed such that the surface layer thereof is in contact with the pressure roll.

FIG. 3 is a schematic configuration diagram showing a fixing unit which is an example of the fixing device of the present embodiment.
As shown in FIG. 3, the fixing unit 82 includes a fixing belt module 86 including a fixing belt 84 that is a fixing member of the present embodiment, and a pressure roll 88 disposed in pressure contact with the fixing belt module 86. ing. A nip portion N where the fixing belt 84 (fixing belt module 86) and the pressure roll 88 come into contact is formed. In the nip portion N, the recording medium P is pressurized and heated to fix the toner image.

  The fixing belt module 86 includes an endless fixing belt 84, a heating roll 89 around which the fixing belt 84 is wound so as to be circulated on the pressure roll 88 side, and is rotationally driven by the rotational force of a motor (not shown). A support roll 90 is provided that stretches the fixing belt 84 from the inside at a position different from the heating roll 89. Further, a support roll 92 that is disposed outside the fixing belt 84 and defines a circulation path thereof, and a posture correction roll 94 that corrects the posture of the fixing belt 84 from the heating roll 89 to the support roll 90 are provided.

  Further, in the downstream area in the nip portion N where the fixing belt module 86 and the pressure roll 88 are in pressure contact with each other and on the inner side of the fixing belt 84, the outer circumference of the heating roll 89 is arranged. A peeling pad 96 for peeling the fixing belt 84 from the surface and a support roll 98 on which the fixing belt 84 is stretched on the downstream side of the nip portion N are provided.

  The heating roll 89 as an example of the driving means in the present invention is a hard roll having a 200 μm-thick fluororesin film formed on the core metal surface as a protective layer for preventing metal abrasion on the surface of the cylindrical metal core made of aluminum. It is a roll. Further, a halogen heater 102 is provided inside the heating roll 89. Further, the support roll 90 is a cylindrical roll formed of aluminum, and a halogen heater 104 is disposed inside as a heating source so as to heat the fixing belt 84 from the inner surface side. Further, spring members (not shown) that press the fixing belt 84 outward are disposed at both ends of the support roll 90.

  The support roll 92 is a cylindrical roll formed of aluminum, and a release layer made of a fluororesin having a thickness of 20 μm is formed on the surface of the support roll 92. This release layer is formed to prevent the offset toner and paper powder from the outer peripheral surface of the fixing belt 84 from accumulating on the support roll 92. A halogen heater 106 is disposed inside the support roll 92 to heat the fixing belt 84 from the outer peripheral surface side. That is, in this embodiment, the fixing belt 84 is heated by the heating roll 89, the support roll 90, and the support roll 92. The halogen heaters 102, 104, and 106 are examples of fixing heating means in the present invention.

  The posture correction roll 94 is a cylindrical roll formed of aluminum, and an end position measuring mechanism (not shown) for measuring the end position of the fixing belt 84 is disposed in the vicinity of the posture correction roll 94. . The posture correcting roll 94 is provided with an axial displacement mechanism (not shown) that displaces the contact position in the axial direction of the fixing belt 84 according to the measurement result of the end position measuring mechanism. Configured to control.

  Moreover, the peeling pad 96 is a block-shaped member having a length corresponding to the heating roll 89 formed of a rigid body such as an iron-based metal or resin, for example. The cross-sectional shape of the peeling pad 96 has a curved inner surface 96A facing the heating roll 89, a pressing surface 96B that presses the fixing belt 84 toward the pressing roll 88, and an angle determined with respect to the pressing surface 96B. And has an outer surface 96 </ b> C that bends the fixing belt 84 and has a substantially arc shape. Specifically, the corner portion G composed of the pressing surface 96B and the outer surface 96C bends the fixing belt 84 pressed against the corner portion G by the pressure roll 88, and the leading end of the recording medium P passes through the corner portion G. In doing so, the leading edge of the recording medium P and the fixing belt 84 are peeled off.

  On the other hand, the pressure roll 88 has a structure in which a cylindrical roll 88A made of aluminum is used as a base, and an elastic layer 88B made of silicone rubber and a release layer made of a fluororesin having a thickness of 100 μm are laminated in this order from the base. It has become. The pressure roll 88 is rotatably supported and is provided in pressure contact with a portion where the fixing belt 84 is wound around the heating roll 89 by a biasing means such as a spring (not shown). As a result, as the heating roll 89 of the fixing belt module 86 rotates in the direction of arrow C, the heating roll 89 rotates in the direction of arrow E following the heating roll 89.

  The surface of the fixing belt 84 is downstream of the heating roll 89 in the rotation direction (arrow C direction) of the fixing belt 84 and upstream of the posture correction roll 94 in the rotation direction (arrow C direction) of the fixing belt 84. An infrared lamp 85, which is an example of an infrared heating means for irradiating the layer side with infrared rays, is provided. On the opposite side of the infrared lamp 85 with respect to the fixing belt 84, a reflecting mirror 87, which is an example of an infrared reflecting member, is provided so that the infrared rays irradiated from the infrared lamp 85 are transmitted to the fixing belt 84 with high efficiency. . The heating temperature of the surface layer of the fixing belt 84 by the infrared lamp 85 is set higher than the heating temperature by any of the halogen heaters 102, 104, and 106. The difference between the highest heating temperature among the halogen heaters 102, 104, and 106 (fixing heating means) and the heating temperature by the infrared lamp 85 (infrared heating means) is preferably 10 ° C. or higher and 100 ° C. or lower, and 30 ° C. or higher and 60 ° C. or lower. More preferred are: Since the fixing belt 84 is flat between the heating roll 89 and the posture correction roll 94, wrinkles generated on the surface of the fixing belt 84 are effectively obtained by heating the surface of the flat fixing belt 84 with the infrared lamp 85. Can take.

<Image forming apparatus>
The image forming apparatus according to the present embodiment includes an image holding member, a charging unit that charges the surface of the image holding member, a latent image forming unit that forms a latent image on the charged surface of the image holding member, and the latent image forming unit. A developing unit that develops an image with toner to form a toner image, a transfer unit that transfers the toner image to a recording medium, and a fixing unit that is a fixing device of the present embodiment that fixes the toner image on the recording medium; .

FIG. 4 is a schematic configuration diagram illustrating a configuration of the image forming apparatus according to the present exemplary embodiment.
As shown in FIG. 4, the image forming apparatus 100 according to the present embodiment is an intermediate transfer type image forming apparatus generally called a tandem type, for example, and includes a plurality of toner images of each color component formed by electrophotography. An image forming unit 1Y, 1M, 1C, and 1K; and a primary transfer unit 10 that sequentially transfers (primary transfer) each color component toner image formed by each image forming unit 1Y, 1M, 1C, and 1K to the intermediate transfer belt 15. A secondary transfer unit 20 that collectively transfers (secondary transfer) the superimposed toner image transferred onto the intermediate transfer belt 15 onto a sheet P as a recording medium, and a fixing device that fixes the secondary transferred image onto the sheet P. 82. Further, the image forming apparatus 100 includes a control unit 40 that controls the operation of each device (each unit).

  The fixing device 82 as an example of the fixing unit is the fixing device of the present embodiment described above, and the fixing device includes the fixing belt which is the fixing member of the present embodiment described above.

  Each of the image forming units 1Y, 1M, 1C, and 1K of the image forming apparatus 100 includes a photoconductor 11 that rotates in the arrow A direction as an example of an image holding body that holds a toner image formed on the surface.

  A charging device 12 for charging the photosensitive member 11 is provided around the photosensitive member 11 as an example of a charging unit for charging the surface of the image holding member. A latent image is formed on the surface of the image holding member charged by the charging unit. As an example of a latent image forming means for forming a laser beam, a laser exposure device 13 for writing an electrostatic latent image on the photosensitive member 11 (the exposure beam is indicated by Bm in the figure) is provided.

  Further, around the photosensitive member 11, each color component toner is accommodated as an example of a developing unit that forms a toner image by developing the latent image formed on the surface of the image holding member with the toner by the latent image forming unit. Then, a developing device 14 for visualizing the electrostatic latent image on the photoconductor 11 with toner is provided, and each color component toner image formed on the photoconductor 11 is transferred to the intermediate transfer belt 15 by the primary transfer unit 10. A primary transfer roll 16 for transferring is provided.

  Further, around the photoconductor 11, a photoconductor cleaner 17 for removing residual toner on the photoconductor 11 is provided, and a charger 12, a laser exposure device 13, a developing device 14, a primary transfer roll 16, and a photoconductor cleaner. Seventeen electrophotographic devices are sequentially arranged along the rotation direction of the photoconductor 11. These image forming units 1Y, 1M, 1C, and 1K are arranged substantially linearly in the order of yellow (Y), magenta (M), cyan (C), and black (K) from the upstream side of the intermediate transfer belt 15. Has been.

The intermediate transfer belt 15 as an intermediate transfer member is formed of a film-like endless belt containing a resin such as polyimide or polyamide as a base layer and containing an appropriate amount of an antistatic agent such as carbon black. The volume resistivity is 10 ⁶ Ωcm or more and 10 ¹⁴ Ωcm or less, and the thickness is, for example, about 0.1 mm.

  The intermediate transfer belt 15 is circulated and driven (rotated) at a predetermined speed in the direction B shown in FIG. 4 by various rolls. As these various rolls, a drive roll 31 that is driven by a motor (not shown) having excellent constant speed to rotate the intermediate transfer belt 15, and an intermediate transfer belt that extends substantially linearly along the arrangement direction of the respective photoreceptors 11. 15, a support roll 32 that supports the intermediate transfer belt 15, a tension applying roll 33 that functions as a correction roll that applies a constant tension to the intermediate transfer belt 15 and prevents the intermediate transfer belt 15 from meandering, and a back roll provided in the secondary transfer unit 20. 25. A cleaning back roll 34 is provided in a cleaning unit that scrapes off residual toner on the intermediate transfer belt 15.

The primary transfer unit 10 includes a primary transfer roll 16 that is disposed to face the photoconductor 11 with the intermediate transfer belt 15 interposed therebetween. The primary transfer roll 16 includes a shaft and a sponge layer as an elastic layer fixed around the shaft. The shaft is a cylindrical bar made of metal such as iron or SUS. The sponge layer is a sponge-like cylindrical roll formed of a blend rubber of NBR, SBR, and EPDM containing a conductive agent such as carbon black and having a volume resistivity of 10 ^7.5 Ωcm or more and 10 ^8.5 Ωcm or less.

  The primary transfer roll 16 is placed in pressure contact with the photoconductor 11 with the intermediate transfer belt 15 in between. Further, the primary transfer roll 16 has a voltage (primary polarity) opposite to the toner charging polarity (negative polarity; the same applies hereinafter). Transfer bias) is applied. As a result, the toner images on the respective photoconductors 11 are sequentially electrostatically attracted to the intermediate transfer belt 15 so that the superimposed toner images are formed on the intermediate transfer belt 15.

  The secondary transfer unit 20 is a secondary roller disposed on the toner image holding surface side of the intermediate transfer belt 15 as an example of a transfer unit that transfers the toner image formed by the back roll 25 and the developing unit to a recording medium. And a transfer roll 22.

The back roll 25 is made of a tube of EPDM and NBR blend rubber with carbon dispersed on the surface, and the inside is made of EPDM rubber. And it is formed so that the surface resistivity may be 10 ⁷ Ω / □ or more and 10 ¹⁰ Ω / □ or less, and the hardness is set to, for example, 70 ° (Asker C: manufactured by Kobunshi Keiki Co., Ltd., the same shall apply hereinafter). The The back roll 25 is disposed on the back side of the intermediate transfer belt 15 to constitute a counter electrode of the secondary transfer roll 22, and a metal power supply roll 26 to which a secondary transfer bias is stably applied is disposed in contact. ing.

On the other hand, the secondary transfer roll 22 includes a shaft and a sponge layer as an elastic layer fixed around the shaft. The shaft is a cylindrical bar made of metal such as iron or SUS. The sponge layer is a sponge-like cylindrical roll formed of a blend rubber of NBR, SBR, and EPDM containing a conductive agent such as carbon black and having a volume resistivity of 10 ^7.5 Ωcm or more and 10 ^8.5 Ωcm or less.

  The secondary transfer roll 22 is placed in pressure contact with the back roll 25 with the intermediate transfer belt 15 in between. Further, the secondary transfer roll 22 is grounded and a secondary transfer bias is formed between the secondary transfer roll 22 and the back roll 25. The toner image is secondarily transferred onto the paper P conveyed to the transfer unit 20.

  Further, on the downstream side of the secondary transfer portion 20 of the intermediate transfer belt 15, an intermediate transfer belt that removes residual toner and paper dust on the intermediate transfer belt 15 after the secondary transfer and cleans the surface of the intermediate transfer belt 15. A cleaner 35 is provided so as to be able to contact and separate.

  On the other hand, on the upstream side of the yellow image forming unit 1Y, a reference sensor (home position sensor) 42 that generates a reference signal serving as a reference for taking image forming timings in the image forming units 1Y, 1M, 1C, and 1K. It is arranged. Further, an image density sensor 43 for adjusting image quality is disposed on the downstream side of the black image forming unit 1K. The reference sensor 42 recognizes a mark provided on the back side of the intermediate transfer belt 15 and generates a reference signal. In response to an instruction from the control unit 40 based on the recognition of the reference signal, each image forming unit 1Y, 1M, 1C, and 1K are configured to start image formation.

  Furthermore, in the image forming apparatus according to the present embodiment, as a transport unit that transports the paper P, the paper storage unit 50 that stores the paper P, and the paper P accumulated in the paper storage unit 50 are taken out at a predetermined timing. A paper feed roll 51 for transport, a transport roll 52 for transporting the paper P fed by the paper feed roll 51, a transport guide 53 for feeding the paper P transported by the transport roll 52 to the secondary transfer unit 20, and a secondary transfer roll 22 is provided with a conveyance belt 55 for conveying the paper P conveyed after the secondary transfer to the fixing device 82 and a fixing entrance guide 56 for guiding the paper P to the fixing device 82.

Next, a basic image forming process of the image forming apparatus of this embodiment will be described.
In the image forming apparatus of the present embodiment, image data output from an image reading device (not shown) or a personal computer (PC) (not shown) is subjected to predetermined image processing by an image processing device (not shown), and then the image data The image forming operation is executed by the forming units 1Y, 1M, 1C, and 1K.

  In the image processing apparatus, predetermined reflectance editing, such as shading correction, positional deviation correction, brightness / color space conversion, gamma correction, frame deletion, color editing, moving editing, and other image editing is performed in advance. Image processing is performed. The image data that has been subjected to image processing is converted into color material gradation data of four colors Y, M, C, and K, and is output to the laser exposure unit 13.

  The laser exposure unit 13 irradiates each of the photoconductors 11 of the image forming units 1Y, 1M, 1C, and 1K with, for example, an exposure beam Bm emitted from a semiconductor laser in accordance with the input color material gradation data. . In each of the photoreceptors 11 of the image forming units 1Y, 1M, 1C, and 1K, the surface is charged by the charger 12, and then the surface is scanned and exposed by the laser exposure unit 13 to form an electrostatic latent image. The formed electrostatic latent images are developed as toner images of respective colors Y, M, C, and K by the respective image forming units 1Y, 1M, 1C, and 1K.

  The toner images formed on the photoconductors 11 of the image forming units 1Y, 1M, 1C, and 1K are transferred onto the intermediate transfer belt 15 in the primary transfer unit 10 where the photoconductors 11 and the intermediate transfer belt 15 are in contact with each other. The More specifically, in the primary transfer portion 10, a voltage (primary transfer bias) having a polarity opposite to the toner charging polarity (minus polarity) is applied to the base material of the intermediate transfer belt 15 by the primary transfer roll 16, and the toner image. Are sequentially superimposed on the surface of the intermediate transfer belt 15 to perform primary transfer.

  After the toner images are sequentially primary transferred onto the surface of the intermediate transfer belt 15, the intermediate transfer belt 15 moves and the toner image is conveyed to the secondary transfer unit 20. When the toner image is transported to the secondary transfer unit 20, the transport unit rotates the paper feed roll 51 in accordance with the timing at which the toner image is transported to the secondary transfer unit 20, and is predetermined from the paper storage unit 50. A sheet P of a different size is supplied. The paper P supplied by the paper feed roll 51 is transported by the transport roll 52, and reaches the secondary transfer unit 20 through the transport guide 53. Before reaching the secondary transfer unit 20, the paper P is temporarily stopped, and the registration roller (not shown) rotates in accordance with the movement timing of the intermediate transfer belt 15 on which the toner image is held. And the position of the toner image are aligned.

  In the secondary transfer unit 20, the secondary transfer roll 22 is pressed against the back roll 25 via the intermediate transfer belt 15. At this time, the sheet P conveyed at the same timing is sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. At this time, when a voltage (secondary transfer bias) having the same polarity as the toner charging polarity (negative polarity) is applied from the power supply roll 26, a transfer electric field is formed between the secondary transfer roll 22 and the back roll 25. Is done. The unfixed toner image held on the intermediate transfer belt 15 is collectively electrostatically transferred onto the paper P in the secondary transfer unit 20 pressed by the secondary transfer roll 22 and the back roll 25. The

  Thereafter, the sheet P on which the toner image has been electrostatically transferred is transported as it is while being peeled off from the intermediate transfer belt 15 by the secondary transfer roll 22, and transported downstream of the secondary transfer roll 22 in the sheet transport direction. It is conveyed to the belt 55. The transport belt 55 transports the paper P to the fixing device 82 in accordance with the optimal transport speed in the fixing device 82. The unfixed toner image on the paper P conveyed to the fixing device 82 is fixed on the paper P by being subjected to a fixing process by heat and pressure by the fixing device 82. Then, the paper P on which the fixed image is formed is conveyed to a paper discharge accommodating portion (not shown) provided in the discharge portion of the image forming apparatus.

  On the other hand, after the transfer onto the paper P is completed, the residual toner remaining on the intermediate transfer belt 15 is conveyed to the cleaning unit as the intermediate transfer belt 15 rotates, and is cleaned by the cleaning back roll 34 and the intermediate transfer belt cleaner 35. It is removed from the intermediate transfer belt 15.

  Although the embodiments of the present invention have been described above, the present invention is not construed as being limited to the above-described embodiments, and various modifications, changes, and improvements can be made, and a range that satisfies the requirements of the present invention. Needless to say, this is feasible.

  Hereinafter, although an Example and a comparative example are given and this embodiment is described in detail in detail, this embodiment is not limited to the following examples. Unless otherwise specified, “part” and “%” are based on mass.

[Example 1]
-Production of substrate-
Prepare a polyamic acid solution with a solid content concentration of 18% using NMP (N-methylpyrrolidone) as a solvent, inject the polyamic acid solution into a centrifugal mold that is an aluminum cylinder, and rotate the centrifugal mold around the axis. A coating film was formed and dried by heating at 145 ° C. for 30 minutes to obtain a dried film. The dried film was removed from the centrifugal mold and set in an imidized mold, and heated at 200 ° C. for 20 minutes and at 380 ° C. for 20 minutes to obtain a polyimide (PI) substrate having a film thickness of 80 μm.

-Formation of elastic layer-
A liquid silicone rubber SE6744 (manufactured by Toray Dow Corning Co., Ltd.) was blade-coated on the prepared PI substrate. After heating at 110 ° C. for 20 minutes, it was heated at 200 ° C. for 4 hours to form an elastic layer.

-Formation of infrared reflective layer-
Nickel electroless plating was performed to form a nickel layer of 0.5 μm on the elastic layer. Using this nickel electroless plating film as an electrode, a 10 μm-thick copper layer (infrared reflective layer) was formed thereon by electrolytic plating (bright copper sulfate bath).

-Formation of surface layer-
A 30 μm thick PFA tube having a diameter 2% smaller than the outer diameter of the elastic layer was prepared, and the PFA tube was set on the inner periphery of the outer mold having an inner diameter 1% larger than the outer diameter of the elastic layer. With the fixing belt formed up to the infrared reflecting layer inside the PFA tube inserted, the PFA tube was removed from the outer mold, covered with the outer periphery of the fixing belt, and heated at 200 ° C. for 30 minutes to form a surface layer.

-Evaluation-
The fixing belt 1 as a fixing member obtained as described above is set in the fixing device shown in FIG. 3, and this fixing device is further mounted on a high-speed copying machine (Fuji Xerox Co., Ltd .: Color 1000 Press) for evaluation. An image forming apparatus was obtained. Using this apparatus, surface layer wrinkle recovery, elastic layer durability, and infrared reflective layer durability were evaluated based on the following criteria. The obtained results are shown in Table 1.

(Surface layer wrinkle recovery)
After passing 100,000 sheets of J paper (Fuji Xerox Co., Ltd.), the cross-sectional curve of the fixing belt surface was measured using Surfcom 1400D (manufactured by Tokyo Seimitsu Co., Ltd.), and the belt surface length was calculated from the cross-sectional curve. The belt surface length in the initial state was L0, and the belt surface length after passing paper was L1, and the surface layer wrinkle recoverability was determined as follows.
○: (L1-L0) / L0 * 100 ≦ 0.05
×: (L1-L0) / L0 * 100> 0.05

(Elastic layer durability)
An elastic layer was collected from the fixing belt after passing through the paper, and a dynamic viscoelasticity test was performed with RHEOVIBRON (manufactured by Orientec). The measurement was performed at 180 ° C., and the elastic layer durability was determined as follows, assuming that the elastic modulus of the elastic layer in the initial state was E′0 and the elastic modulus after storage was E′1.
: (E'1-E'0) / E'0 * 100 ≤2.5
○: 2.5 <(E'1-E'0) / E'0 * 100 ≤5
×: (E'1-E'0) / E'0 * 100> 5

(Infrared reflective layer durability)
Visual observation and digital microscope VHX900 (manufactured by Keyence Corporation) were used to confirm the presence or absence of cracks in the infrared reflective layer. In addition, an infrared reflective layer was collected from the fixing belt after passing the paper, and a dynamic viscoelasticity test similar to the elastic layer durability evaluation was performed. The storage elastic modulus of the infrared reflecting layer in the initial state was E′2, and the storage elastic modulus of the infrared reflection after passing paper was E′3.
◎: No cracking and (| E'3-E'2 |) / E'2 * 100 ≤5
○: No crack occurred and 5 <(| E'3-E'2 |) / E'2 * 100 ≤10
○-: No cracking and 10 <(| E'3-E'2 |) / E'2 * 100
Δ: Crack occurred

[Example 2]
Mixing 100 parts of tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (hereinafter referred to as PFA) with 5 parts of aluminum borate serving as a nucleating agent for foaming, extruding with a twin-screw extruder to produce pellets, Set the pellet, extrude the pellet from the cylinder while adding nitrogen gas at a constant pressure, cool it while winding it with a hot roll at a temperature lower than the die temperature, foaming rate 45%, cell (bubble) diameter 5μm, A foamed fluororesin tube having a thickness of 30 μm was produced. After forming up to the infrared reflective layer in the same manner as in Example 1, a heat insulating layer made of foamed fluororesin and a surface layer on the heat insulating layer are formed on the infrared reflective layer by the same process as the surface layer forming process in Example 1. The fixing belt 2 was formed.
Evaluation was performed in the same manner as in Example 1 using the fixing belt 2. The obtained evaluation results are shown in Table 1.

[Example 3]
After forming the elastic layer in the same manner as in Example 1, 100 parts of addition-curable dimethylsilicone rubber and 10 parts of amorphous alumina particles having an average particle size of 5 μm were added and mixed to form a coating solution. An infrared reflective layer was formed by coating. A surface layer was formed on the infrared reflective layer in the same manner as in Example 1 to prepare the fixing belt 3.
Evaluation was performed in the same manner as in Example 1 using the fixing belt 3. The obtained evaluation results are shown in Table 1.

[Example 4]
After forming the elastic layer in the same manner as in Example 1, 10 parts of plate-like alumina particles having an average particle size of 5 μm and an average thickness of 0.2 μm were added to 100 parts of addition-curable dimethyl silicone rubber and mixed, An infrared reflective layer was formed on the elastic layer by blade coating. A surface layer was formed on the infrared reflecting layer in the same manner as in Example 1 to prepare the fixing belt 4.
Evaluation was performed in the same manner as in Example 1 using the fixing belt 4. The obtained evaluation results are shown in Table 1.

[Example 5]
After forming the infrared reflective layer in the same manner as in Example 4, the heat insulating layer and the surface layer described in Example 2 were formed on the infrared reflective layer, and the fixing belt 5 was produced.
Evaluation was performed in the same manner as in Example 1 using the fixing belt 5. The obtained evaluation results are shown in Table 1.

[Example 6]
After forming the heat insulating layer in the same manner as in Example 5, a PFA tube containing 10% PTFE particles having an average particle diameter of 3 μm was formed on the heat insulating layer in the same process as in Example 1 to produce a fixing belt 6. .
Evaluation was performed in the same manner as in Example 1 using the fixing belt 6. The obtained evaluation results are shown in Table 1.

[Comparative Example 1]
A fixing belt 7 was obtained in the same manner as in Example 1 except that the infrared reflecting layer was not provided. Evaluation was performed in the same manner as in Example 1 using the fixing belt 7. The obtained evaluation results are shown in Table 1.

  As can be seen from Table 1, it is possible to remove wrinkles generated on the surface layer by using the fixing belt of the embodiment. Moreover, it becomes possible to prevent deterioration of the elastic layer and the infrared reflection layer due to infrared heating.

82 Fixing unit 84 Fixing belt 85 Infrared lamp 86 Fixing belt module 87 Reflecting mirror 88 Pressure roll 89 Fixing belt driving roll 90, 92 Tension roll 94 Posture correction roll 96 Peeling pads 102, 104, 106 Halogen heater 200 Base 210 Elastic layer 220 Infrared reflective layer 230 Surface layer 240 Heat insulation layer

Claims (9)

  A fixing member comprising at least a base, an elastic layer, an infrared reflecting layer, and a surface layer in this order.   The fixing member according to claim 1, further comprising a heat insulating layer between the infrared reflective layer and the surface layer.   The fixing member according to claim 1, wherein the infrared reflecting layer is a heat-resistant elastomer containing at least an infrared reflecting agent.   The fixing member according to claim 3, wherein the infrared reflecting agent is a plate-like particle.   The fixing member according to claim 2, wherein the heat insulating layer is a foamed fluororesin.   The fixing member according to claim 1, wherein the surface layer is a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer containing an infrared absorption accelerator.   The fixing member according to claim 6, wherein the infrared absorption accelerator is polytetrafluoroethylene particles or carbon. The fixing member according to any one of claims 1 to 7, which is supported so as to be capable of circulating movement,
Driving means for circulatingly driving the fixing member;
A pressure roll pressed against the fixing member and sandwiching a recording medium with the fixing member;
Fixing heating means for heating the fixing member;
Infrared heating means for heating the surface layer to be higher than the temperature heated by the fixing heating means by irradiating infrared rays from the surface layer side of the fixing member;
A fixing device. An image carrier,
Charging means for charging the surface of the image carrier;
Latent image forming means for forming a latent image on the surface of the charged image carrier;
Developing means for developing the latent image with toner to form a toner image;
Transfer means for transferring the toner image to a recording medium;
Fixing means for fixing the toner image to the recording medium, the fixing means being the fixing device according to claim 8;
An image forming apparatus comprising: