JP2016057501A - Slide member for fixing device, fixing device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide member for a fixing device that can suppress the generation of wrinkles on a sheet that is a recording medium in fixing a toner image onto the sheet.SOLUTION: There is provided a slide member for a fixing device 101 that includes a fluorine resin and inorganic material particles 120, and has convex parts derived from the inorganic material particles on a slide surface 112A in contact with a slide target member.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sliding member for a fixing device, 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, an unfixed toner image formed on a recording medium such as recording paper is fixed by a fixing device.
The fixing device includes, for example, a configuration including a heating roll and a pressure belt arranged in contact with the heating roll, or a pressure roll arranged in contact with the heating belt and the heating belt. There is known a fixing device called a belt nip system having a configuration.

  Patent Document 1 includes a film having a conductive portion, a support member that supports the film, and magnetic flux generation means that generates magnetic flux, and eddy current is generated in the film by the magnetic flux generated by the magnetic flux generation means. An image heating apparatus for generating and heating an image on a recording material by the heat of the film generated by the eddy current, and having a sliding member provided between the film and the support member, the film being the sliding member And an image heating apparatus characterized by sliding.

  In Patent Document 2, in an image heating apparatus that heats an image on a recording material by passing the recording material between heating nips in which a heating member and a pressure member are pressed against each other, the heating member includes: A heating heater having an energization heating resistor, a film whose one surface slides on the heating heater and the other surface moves together in contact with the recording material, and a supporting member for supporting the film. An image heating apparatus is disclosed in which a groove for holding heat-resistant grease for ensuring film slidability is provided on the film sliding surface of the support member.

  In Patent Document 3, a rotatable rotating member, an endless belt that can move while contacting the rotating member, and an inner end of the endless belt, the endless belt is pressed against the rotating member. A pressure member that forms a nip portion through which the recording material passes between the rotating member and the endless belt, and is provided between the endless belt and the pressure member. There is disclosed a fixing device including a sliding member having irregularities formed thereon.

JP-A-9-319242 JP 2000-306655 A Japanese Patent Laying-Open No. 2005-77847

  An object of the present invention is to provide a sliding member for a fixing device in which generation of paper wrinkles is suppressed when a toner image is fixed on paper as a recording medium.

The above object is solved by the following means.
The invention according to claim 1 is a sliding member for a fixing device which includes a fluororesin and inorganic material particles, and has a convex portion derived from the inorganic material particles on a sliding surface in contact with the sliding member.
The invention according to claim 2 is the sliding member for a fixing device according to claim 1, wherein the inorganic material particles are hollow particles.
The invention according to claim 3 is the sliding member for a fixing device according to claim 1 or 2, wherein the inorganic material particles have an average particle diameter of 45 μm or less.
The invention according to claim 4 is the sliding member for a fixing device according to any one of claims 1 to 3, wherein an average particle diameter of the inorganic material particles is 20 μm or more.
The invention according to claim 5 is a sliding member for a fixing device according to any one of claims 1 to 4, which is in the form of a sheet.
The invention according to claim 6 is the sliding member for a fixing device according to claim 5, comprising: a base material layer; and a sliding layer disposed on the base material layer and having the sliding surface.
The invention according to claim 7 is the first rotating body, the second rotating body disposed in contact with the outer peripheral surface of the first rotating body, and the second rotating body disposed inside the second rotating body. A pressing member that presses the second rotating body against the first rotating body from an inner peripheral surface of the second rotating body, and an inner peripheral surface of the second rotating body and the pressing member. The sheet-like fixing device sliding member according to claim 5 or 6 in contact with the inner peripheral surface of the rotating body, a heating source for heating at least one of the first rotating body and the second rotating body, A fixing device.
According to an eighth aspect of the present invention, there is provided an image carrier, a charging device that charges the surface of the image carrier, a latent image forming device that forms a latent image on the surface of the charged image carrier, and the latent image. An image comprising: a developing device that develops toner with toner to form a toner image; a transfer device that transfers the toner image onto a recording medium; and a fixing device according to claim 7 that fixes the toner image onto the recording medium. Forming device.

According to the first aspect of the present invention, the toner image is printed on the paper that is the recording medium, as compared with the case where the sliding surface that includes the fluororesin and does not have the convex portion derived from the inorganic material particles on the sliding surface that contacts the sliding member. There is provided a sliding member for a fixing device in which the occurrence of paper wrinkles is suppressed when fixing to a paper.
According to the second aspect of the present invention, there is provided a sliding member for a fixing device that contributes to labor saving of energy required for fixing as compared with the case where the inorganic material particles are non-hollow particles.

According to the third aspect of the invention, the fixing device can suppress the occurrence of paper wrinkles when fixing the toner image on the paper as the recording medium, as compared with the case where the average particle diameter of the inorganic material particles exceeds 45 μm. A sliding member is provided.
According to the fourth aspect of the invention, there is provided a sliding member for a fixing device that contributes to labor saving of energy required for fixing as compared with the case where the average particle diameter of the inorganic material particles is less than 20 μm.

  According to the fifth and sixth aspects of the invention, the sheet-like sliding member for a fixing device includes a fluororesin and does not have a convex portion derived from inorganic material particles on a sliding surface in contact with the sliding member. In comparison, there is provided a sheet-like sliding member for a fixing device in which generation of paper wrinkles is suppressed when a toner image is fixed on paper as a recording medium.

  According to the seventh and eighth aspects of the invention, there is provided a sheet-like fixing device sliding member that includes a fluororesin and does not have a convex portion derived from inorganic material particles on a sliding surface that comes into contact with the sliding member. A fixing device and an image forming apparatus are provided in which generation of paper wrinkles is suppressed when a toner image is fixed on paper as a recording medium as compared with the case where the toner image is applied.

FIG. 4 is a schematic diagram illustrating an example of a configuration of a sliding member for a fixing device according to the present exemplary embodiment. FIG. 2 is a schematic diagram illustrating an enlarged cross-section in the thickness direction of the fixing device sliding member illustrated in FIG. 1. 1 is a schematic diagram illustrating an example of a configuration of a fixing device according to an exemplary embodiment. FIG. 10 is a schematic diagram illustrating another example of the configuration of the fixing device according to the exemplary embodiment. 1 is a schematic diagram illustrating a configuration example of an image forming apparatus according to an exemplary embodiment.

  Hereinafter, a sliding member for a fixing device, a fixing device, and an image forming apparatus according to the present embodiment will be described in detail.

<Sliding member for fixing device>
The fixing device sliding member according to the present embodiment includes a fluororesin and inorganic material particles, and has a convex portion derived from the inorganic material particles on a sliding surface in contact with the sliding member. .
The shape of the fixing device sliding member according to the present embodiment is not particularly limited. However, as a typical example, a sheet-like fixing device sliding member (hereinafter referred to as “sliding”) composed of a base material layer and a sliding layer will be described below. The “member” or “sliding sheet” may be mainly described.

FIG. 1 schematically shows an example of the configuration of the sliding member according to the present embodiment. FIG. 2 schematically shows an enlarged cross-section in the thickness direction of a part of the sliding member according to the present embodiment. A sliding member 101 shown in FIG. 1 is a sheet-like sliding member (sliding sheet) formed by laminating a base material layer 110 and a sliding layer 112 having a sliding surface 112A that contacts the sliding member. ).
The sliding layer 112 includes a fluororesin and inorganic material particles 120, and a sliding surface in which convex portions derived from the inorganic material particles are formed on the surface (sliding surface) opposite to the surface in contact with the base material layer 110. It is a surface. The “convex portion derived from the inorganic material particles” means that a part of the inorganic material particles embedded in the sliding layer 112 is raised from the sliding surface 112A or covered with a fluororesin. Means that a convex portion is formed.
In addition, from the viewpoint of ensuring slidability, it is preferable that the convex portion is formed in a state where the inorganic material particles 120 are covered with the fluororesin on the sliding surface 112A.

The reason why generation of paper wrinkles is suppressed by using the sliding member according to the present embodiment is considered as follows.
Along with the increase in the speed of electrophotographic apparatuses, the adoption of belt fixing devices that can obtain a wide contact width even with a small-diameter roll by bringing the belt into contact with the roll is progressing. In such a belt fixing device, the belt is driven by the opposite drive roll to convey the paper. At this time, in order to obtain a pressing force against the roll, the sliding property between the support member supporting the belt inner surface and the belt inner surface is sufficient. Otherwise, paper wrinkles are likely to occur when the paper is conveyed at the contact portion. For this reason, the sliding member (sliding sheet) for ensuring the slidability between the support member and the belt inner surface is provided. Since the sliding member has a low coefficient of friction as a material, the sliding member is often mainly composed of a fluorine-based material. However, even if a fluorine-based material is used, sufficient sliding performance is achieved with solid lubrication with the belt inner surface. It is difficult to obtain. Therefore, sliding oil or grease for assisting slidability is interposed between the sliding member and the inner surface of the belt to reduce sliding resistance. However, if sufficient sliding oil or grease cannot be interposed between the sliding member and the belt inner surface, sufficient slidability cannot be ensured, and paper wrinkles are likely to occur.

On the other hand, in the sliding member according to this embodiment, the sliding layer 112 constituting the sliding surface 112A includes a fluororesin, and the sliding surface 112A has a convex portion due to the inorganic material particles 120. To do. For this reason, the sliding surface 112A is brought into point contact with the inner surface of the belt, which is a member to be slid, at the convex portion, so that sliding resistance is suppressed, and a gap is secured between the sliding surface 112A and the inner surface of the belt. Sliding oil and grease are likely to intervene. Therefore, it is considered that the sliding member according to the present embodiment is sufficiently slidable between the inner surface of the belt and the generation of paper wrinkles is suppressed.
Hereinafter, the configuration of the sliding member according to the present embodiment will be specifically described.

(Sliding layer)
The sliding layer 112 includes a fluororesin and inorganic material particles, and has a convex portion derived from the inorganic material particles on a sliding surface in contact with the sliding member. Having a convex portion derived from inorganic material particles on the sliding surface 112A, the lubricant (oil) is held, and the lubricant (oil) can be easily supplied to the contact area with the sliding member. The friction coefficient can be kept low.

(Fluorine resin)
Examples of the fluororesin contained in the sliding layer 112 include polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and ethylene-tetrafluoroethylene copolymer. (ETFE), or modified products thereof, and the like. From the viewpoint of keeping the friction coefficient on the sliding surface low, it is preferable to use fully fluorinated PFA, PTFE, or FEP.

(Inorganic material particles)
Examples of the inorganic material particles 120 included in the sliding layer 112 include hollow particles or non-hollow particles made of an inorganic material, and hollow particles made of an inorganic material (hereinafter referred to as “inorganic hollow particles”). Is preferred). Since the inorganic material particles have a hollow structure, the heat insulation is improved by adding to the fluororesin, the inflow of heat from the opposing fixing roll to the support member inside the belt is reduced, and the warm-up time of the fixing device is reduced. Energy savings such as shortening can be improved.

The inorganic hollow particles contained in the sliding layer 112 are generally known by the name “glass balloon” from the viewpoint of strength and availability, and the outer shell is formed to contain silica (silicon dioxide). Hollow silica is preferred.
In addition, hollow particles and non-hollow particles made of alumina, zirconia, or the like are also included.

The average particle size of the inorganic material particles 120 included in the sliding layer 112 is not particularly limited, but is, for example, 15 μm to 60 μm, and more preferably 20 μm to 45 μm.
When the average particle diameter of inorganic hollow particles such as glass balloons is 20 μm or more, an increase in true density is suppressed, and the thermal conductivity of the particles themselves is suppressed low. Therefore, a sliding sheet having high heat insulating properties can be obtained, which can contribute to energy saving of fixing.
On the other hand, when the average particle diameter of the glass balloon is 45 μm or less, the inorganic hollow particles are prevented from being destroyed by the pressure applied to the contact portion when used as a sliding member. Therefore, it is possible to suppress the convex portion of the sliding surface from decreasing with time, to ensure slidability over a long period of time, and to suppress the occurrence of paper wrinkles.
In addition, the average particle diameter of the inorganic material particles 120 in the present embodiment is obtained by dissolving the sliding layer 112 with a solvent to extract the inorganic material particles, and expanding the particles with an optical microscope (the maximum particle diameter) of 50 particles. Is obtained by arithmetic average.

  From the viewpoint of forming convex portions derived from the inorganic material particles 120 on the sliding surface 112A of the sliding sheet 101 and suppressing the falling off from the sliding layer 112, the particle size of the inorganic material particles 120 is the sliding size. The thickness of the moving layer 112 is preferably 0.4 times or more and 3.3 times or less, more preferably 0.5 times or more and 2 times or less, and further preferably 0.7 times or more and 1.5 times or less. .

  The content of the inorganic material particles in the sliding layer 112 is an amount by which the convex portion due to the inorganic material particles is formed on the sliding surface 112A. Although depending on the particle diameter of the inorganic airborne particles and the thickness of the sliding layer, from the viewpoint of ensuring the slidability by the convex portion on the sliding surface and suppressing the occurrence of cracks and breakage of the sliding layer 112. For example, it is preferably 6 parts by mass or more and 170 parts by mass or less, and more preferably 10 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the fluororesin.

(Other additives)
In addition to the fluororesin and inorganic material particles, the sliding layer 112 may contain conductive carbon or the like as other additives as necessary.
The content of other additives is desirably 5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the fluororesin.

  The thickness of the sliding layer 112 is set according to the content of inorganic material particles in the sliding layer, the type of the fluororesin, the presence or absence of the base material layer 110, and the like. From the viewpoint of suppressing cracks and breakage of the sliding layer and reducing the manufacturing cost, the thickness of the sliding layer 112 is preferably 10 μm or more and 50 μm or less, and more preferably 20 μm or more and 40 μm or less.

[Base material layer]
The base material layer 110 is a layer provided as necessary mainly for the purpose of suppressing the elongation of the sliding layer 112.

  The base material layer 110 is preferably configured to include at least a resin. As resin which can comprise the base material layer 110, a polyimide resin, a polyamide resin, a polyamide-imide resin, a polyetherester resin, a polyarylate resin, a polyester resin etc. are mentioned, for example. Among these, a polyimide resin is desirable from the viewpoint of excellent heat resistance and mechanical strength.

  The thickness of the base material layer 110 is desirably 50 μm or more and 100 μm or less, and more desirably 60 μm or more and 80 μm or less from the viewpoint of suppressing elongation of the sliding layer 112 and suppressing manufacturing cost.

In addition, the sliding member which concerns on this embodiment is not limited to the said layer structure, For example, the single layer structure containing a fluororesin and an inorganic material particle may be sufficient.
Moreover, the structure where the base material layer and the sliding layer were laminated | stacked through the contact bonding layer may be sufficient.

[Manufacturing method of sliding member]
A method for manufacturing the sliding sheet 101 according to the present embodiment is not particularly limited, and for example, it can be manufactured by the following method.
First, a polyimide precursor solution is prepared as a coating solution for forming the base material layer 110, and the polyimide precursor solution is coated on a supporting substrate by a known coating method such as a bar coater, and then dried by heating. A dry coating film of the precursor is formed.
Next, a dispersion liquid containing a fluororesin and inorganic material particles is spray-coated on the dried coating film of the polyimide precursor, and baked by a hot air oven or the like. Thereby, the sliding sheet 101 by which the sliding layer containing a fluororesin and an inorganic material particle was laminated | stacked on the base material layer made from a polyimide is obtained.

  The sliding member 101 according to the present embodiment prepares, for example, a base material layer sheet serving as a base material layer and a sliding layer sheet containing a fluororesin and inorganic material particles, and these sheets are bonded to the adhesive layer. It is also possible to produce by sticking together.

<Fixing device>
The fixing device according to the present embodiment includes a first rotator, a second rotator disposed in contact with an outer peripheral surface of the first rotator, the second rotator, and the second rotator. A pressing member that presses the second rotating body against the first rotating body from an inner peripheral surface of the body, and an inner peripheral surface of the second rotating body and the pressing member. The sheet-like fixing device sliding member according to the present embodiment, which is in contact with the inner peripheral surface of the two-rotor, and a heating source that heats at least one of the first and second rotors. Since the fixing device according to the present embodiment includes the sliding member according to the present embodiment, generation of paper wrinkles during fixing is suppressed.

The fixing device according to this embodiment has various configurations, and the following two embodiments will be specifically described.
As a first embodiment, a fixing device including a heating roll having a heating source and a pressure belt on which a pressing pad is pressed will be described.
As a second embodiment, a fixing device including a heating belt having a heating source and a pressing pad pressed, and a pressure roll will be described.
As the sheet-like sliding member in these fixing devices, the sliding member according to the present embodiment is applied.

[Fixing Device According to First Embodiment]
FIG. 3 is a schematic diagram illustrating the configuration of the fixing device 60 according to the first embodiment.

  The fixing device 60 includes a heating roll 61 (an example of a first rotating body), a pressure belt 62 (an example of a second rotating body), a pressing pad 64 (an example of a pressing member), and a sliding member 101 (this embodiment). An example of a sliding member according to the embodiment) and a halogen lamp 66 (an example of a heating source).

  The heating roll 61 and the pressure belt 62 are applied in contact with each other on the outer peripheral surface. The pressure belt 62 may be pressed against the heating roll 61, and the heating roll 61 may be pressed against the pressure belt 62. In a region where the heating roll 61 and the pressure belt 62 are in contact with each other, a sandwiching region N (nip portion) is formed.

The heating roll 61 includes a halogen lamp 66 (an example of a heating source) therein. The heat source is not limited to the halogen lamp, and may be another heat generating member that generates heat.
A temperature sensitive element 69 is arranged in contact with the outer peripheral surface of the heating roll 61. The lighting of the halogen lamp 66 is controlled based on the temperature measurement value by the temperature sensing element 69, and the surface temperature of the heating roll 61 is maintained at a set temperature (for example, 150 ° C.).
The heating roll 61 is configured, for example, by laminating a heat-resistant elastic body layer 612 and a release layer 613 around a metal core (cylindrical core) 611 in this order.

The pressure belt 62 is disposed in contact with the outer peripheral surface of the heating roll 61.
The pressure belt 62 is rotatably supported by a pressing pad 64 and a belt traveling guide 63 disposed therein.

The pressing pad 64 is disposed inside the pressure belt 62 and applies to the heating roll 61 via the pressure belt 62.
The pressing pad 64 includes a front sandwiching member 64 a on the entrance side of the sandwiching region N and a peeling sandwiching member 64 b on the exit side of the sandwiching region N.
The front clamping member 64a is configured in a concave shape along the outer peripheral shape of the heating roll 61, and ensures the length (distance in the sliding direction) of the clamping region N.
The peeling nipping member 64b is configured to protrude from the outer peripheral surface of the heating roll 61, causes local distortion in the heating roll 61 in the exit area of the nipping area N, and heats the recording medium after fixing. Peeling from the roll 61 is facilitated.

The sliding member 101 is formed in a sheet shape, and is disposed between the pressure belt 62 and the pressing pad 64 so that the sliding surface thereof is in contact with the inner peripheral surface of the pressure belt 62 that is a sliding member. ing.
The sliding member 101 is disposed so as to cover the front sandwiching member 64a and the peeling sandwiching member 64b in order to reduce the sliding resistance between the inner peripheral surface of the pressure belt 62 and the pressing pad 64.

The support member 65 supports the pressing pad 64 and the sliding member 101. The support member 65 is made of metal, for example.
A belt traveling guide 63 is attached to the support member 65. The pressure belt 62 rotates along the belt traveling guide 63.
A lubricant supply device 67 that is a means for supplying a lubricant (oil) to the inner peripheral surface of the pressure belt 62 may be attached to the belt traveling guide 63.

  On the downstream side of the sandwiching area N, a peeling member 70 is provided as an auxiliary means for peeling the recording medium. The peeling member 70 includes a peeling claw 71 and a holding member 72 that holds the peeling claw 71. The peeling claw 71 is arranged in a state of being close to the heating roll 61 in a direction (counter direction) opposite to the rotation direction of the heating roll 61.

  The heating roll 61 is rotated in the direction of arrow C by a driving device (not shown), and the pressure belt 62 is rotated in the direction opposite to the rotation direction of the heating roll 61 following this rotation.

  The sheet K (recording medium) having the unfixed toner image is guided by the fixing inlet guide 56 and conveyed to the sandwiching area N. When the paper K passes through the sandwiching area N, the toner image on the paper K is fixed by pressure and heat acting on the sandwiching area N.

[Fixing Device According to Second Embodiment]
FIG. 4 is a schematic diagram illustrating a configuration of a fixing device 80 according to the second embodiment.

  The fixing device 80 includes a pressure roll 88 (an example of a first rotating body), a heating belt 84 (an example of a second rotating body), a pressing pad 87 (an example of a pressing member), and a sliding member 101 (this embodiment). 1 is an electromagnetic induction heat generation type fixing device including an example of a sliding member according to an embodiment and an electromagnetic induction device 90 (an example of a heating source).

The pressure roll 88 is arranged to be pressed against the outer peripheral surface of the heating belt 84, and a sandwiching area N (nip portion) is formed in an area where the pressure roll 88 and the heating belt 84 are in contact with each other.
The pressure roll 88 includes, for example, a base material layer 88A, an elastic layer 88B, and a release layer 88C.

  The heating belt 84 has an endless structure in which, for example, a base material layer, a heat generation layer that generates heat by electromagnetic induction, an elastic layer, and a release layer are laminated in order from the inner peripheral side.

A pressing pad 87 is disposed inside the heating belt 84 at a position facing the pressure roll 88. The pressing pad 87 is supported by the support member 86, the heating belt 84 is wound around, and the heating belt 84 is pressed against the pressure roll 88. The pressing pad 87 is a member made of, for example, metal, heat resistant resin, heat resistant rubber or the like.
For example, a lubricant supply device (not shown) that is a means for supplying a lubricant (oil) to the inner peripheral surface of the heating belt 84 may be attached upstream of the pressing pad 87.

  The sliding member 101 is formed in a sheet shape, and is disposed between the heating belt 84 and the pressing pad 87 so that the sliding surface is in contact with the inner peripheral surface of the heating belt 84 that is a sliding member. .

The electromagnetic induction device 90 is disposed at a position facing the pressure roll 88 with the heating belt 84 interposed therebetween, and heats the heat generation layer of the heating belt 84 by electromagnetic induction.
The electromagnetic induction device 90 incorporates an electromagnetic induction coil (excitation coil) 91. The electromagnetic induction device 90 applies an alternating current to the electromagnetic induction coil 91 to generate a magnetic field, changes this magnetic field with an excitation circuit, and generates an eddy current in the heat generation layer of the heating belt 84. This eddy current is converted into heat (Joule heat) by the electrical resistance of the heat generating layer, and the surface of the heating belt 84 generates heat.

  The heating belt 84 is rotated in the direction of arrow C by a driving device (not shown), and the pressure roll 88 is rotated in the direction opposite to the rotation direction of the heating belt 84 following this rotation.

  The paper K (recording medium) having the unfixed toner image T is conveyed to the sandwiching area N of the fixing device 80. When the paper K passes through the sandwiching area N, the toner image on the paper K is fixed by pressure and heat acting on the sandwiching area N.

In the fixing devices 60 and 80 according to the first and second embodiments, the sliding surface of the sliding sheet 101 is in contact with the inner peripheral surface of the pressure belt 62 or the heating belt 84. The sliding member which concerns on a form does not necessarily need to be a sheet form.
For example, in the fixing device 60 of the first embodiment, the inside of the pressure belt 62 of the pressure member (the pressure pad 64 and the support member 65) that presses the pressure belt 62 from the inner surface to the heating roll 61 without providing the sliding sheet 101. A sliding layer that includes a fluororesin and inorganic material particles in a region (sliding surface) that can be in contact with the peripheral surface and has a convex portion derived from the inorganic material particles may be provided on the sliding surface.
Also in the fixing device 80 of the second embodiment, the inside of the heating belt 84 of a pressing member (supporting member 86 and pressing pad 87) that presses the heating belt 84 from the inner surface to the pressure roll 88 without providing the sliding sheet 101. A sliding layer that includes a fluororesin and inorganic material particles in a region (sliding surface) that can be in contact with the peripheral surface and has a convex portion derived from the inorganic material particles may be provided on the sliding surface.

<Image forming apparatus>
An image forming apparatus according to this embodiment includes an image carrier, a charging device that charges the surface of the image carrier, a latent image forming device that forms a latent image on the charged surface of the image carrier, A developing device that develops a latent image with toner to form a toner image, a transfer device that transfers the toner image onto a recording medium, and a fixing device according to the present embodiment that fixes the toner image onto a recording medium. .

  Hereinafter, an image forming apparatus according to the present embodiment will be described by taking an electrophotographic image forming apparatus as an example. The image forming apparatus according to the present embodiment is not limited to an electrophotographic image forming apparatus, but is a known image forming apparatus other than the electrophotographic system (for example, an inkjet recording apparatus including an endless belt for paper conveyance). It's okay.

  FIG. 5 is a schematic diagram illustrating an example of the configuration of the image forming apparatus 100 according to the present embodiment. The image forming apparatus 100 includes the fixing device 60 of the first embodiment described above. The image forming apparatus 100 may include the fixing device 80 according to the second embodiment described above instead of the fixing device 60.

  The image forming apparatus 100 is an intermediate transfer type image forming apparatus generally called a tandem type. The image forming apparatus 100 includes image forming units 1Y, 1M, 1C, and 1K on which toner images of each color are formed by an electrophotographic method, and a primary transfer unit that sequentially transfers (primary transfer) each color toner image to an intermediate transfer belt 15. 10, a secondary transfer unit 20 that batch-transfers (secondary transfer) the superimposed toner image transferred onto the intermediate transfer belt 15 to the paper K as a recording medium, and fixes the secondary transferred image onto the paper K. And a control unit 40 that controls the operation of each device (each unit).

The image forming units 1Y, 1M, 1C, and 1K are in the order of 1Y (yellow unit), 1M (magenta unit), 1C (cyan unit), and 1K (black unit) from the upstream side of the intermediate transfer belt 15. Are arranged in a substantially straight line.
Each of the image forming units 1Y, 1M, 1C, and 1K includes a photoconductor 11 (an example of an image carrier). The photoconductor 11 rotates in the direction of arrow A.

  Around the photoreceptor 11, there are a charger 12 (an example of a charging device), a laser exposure device 13 (an example of a latent image forming device), a developing device 14 (an example of a developing device), a primary transfer roll 16, The photoconductor cleaner 17 is sequentially disposed along the rotation direction of the photoconductor 11.

The charger 12 charges the surface of the photoconductor 11.
The laser exposure device 13 emits an exposure beam Bm to form an electrostatic latent image on the photoconductor 11.
The developing device 14 stores toner of each color, and visualizes the electrostatic latent image on the photoreceptor 11 with toner.
The primary transfer roll 16 transfers the toner image formed on the photoconductor 11 to the intermediate transfer belt 15 in the primary transfer unit 10.
The photoconductor cleaner 17 removes residual toner on the photoconductor 11.

The intermediate transfer belt 15 is a belt made of a material obtained by adding an antistatic agent such as carbon black to a resin such as polyimide or polyamide. The intermediate transfer belt 15 has a volume resistivity of, for example, 10 ⁶ Ωcm or more and 10 ¹⁴ Ωcm or less, and a thickness of, for example, 0.1 mm.

The intermediate transfer belt 15 is supported by a drive roll 31, a support roll 32, a tension applying roll 33, a back roll 25, and a cleaning back roll 34, and is circulated and driven (rotated) in the direction of arrow B according to the rotation of the drive roll 31. .
The driving roll 31 is driven by a motor (not shown) having excellent constant speed, and rotates the intermediate transfer belt 15.
The support roll 32 supports the intermediate transfer belt 15 that extends substantially linearly along the arrangement direction of the four photoconductors 11 together with the drive roll 31.
The tension applying roll 33 functions as a correction roll that applies a certain tension to the intermediate transfer belt 15 and suppresses meandering of the intermediate transfer belt 15.
The back roll 25 is provided in the secondary transfer unit 20, and the cleaning back roll 34 is provided in a cleaning unit that scrapes residual toner on the intermediate transfer belt 15.

The primary transfer roll 16 is disposed in pressure contact with the photoconductor 11 with the intermediate transfer belt 15 interposed therebetween to form the primary transfer portion 10.
The primary transfer roll 16 is applied with a voltage (primary transfer bias) having a polarity opposite to the toner charging polarity (negative polarity; the same applies hereinafter). As a result, the toner images on the respective photoconductors 11 are sequentially electrostatically attracted to the intermediate transfer belt 15 to form toner images superimposed on the intermediate transfer belt 15.
The primary transfer roll 16 includes a shaft (for example, a metal cylindrical rod such as iron or SUS) and an elastic layer (for example, a blend rubber sponge layer containing a conductive agent such as carbon black) fixed around the shaft. A cylindrical roll. The primary transfer roll 16 has a volume resistivity of, for example, 10 ^7.5 Ωcm or more and 10 ^8.5 Ωcm or less.

The secondary transfer roll 22 is disposed in pressure contact with the back roll 25 with the intermediate transfer belt 15 interposed therebetween, thereby forming the secondary transfer portion 20.
The secondary transfer roll 22 forms a secondary transfer bias between the rear roll 25 and secondarily transfers the toner image onto the paper K (recording medium) conveyed to the secondary transfer unit 20.
The secondary transfer roll 22 includes a shaft (for example, a metal cylindrical rod such as iron or SUS) and an elastic layer (for example, a blend rubber sponge layer containing a conductive agent such as carbon black) fixed around the shaft. It is a configured cylindrical roll. The secondary transfer roll 22 has a volume resistivity of, for example, 10 ^7.5 Ωcm or more and ^108.5 Ωcm or less.

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 forms a transfer electric field with the secondary transfer roll 22.
The back roll 25 is configured, for example, by covering a rubber base material with a tube of blend rubber in which carbon is dispersed. The back roll 25 has a surface resistivity of, for example, 10 ⁷ Ω / □ or more and 10 ¹⁰ Ω / □ or less, and a hardness of, for example, 70 ° (Asker C: manufactured by Kobunshi Keiki Co., Ltd., the same shall apply hereinafter).
A metal power supply roll 26 is disposed in contact with the back roll 25. The power supply roll 26 applies a voltage (secondary transfer bias) having the same polarity as the charging polarity (minus polarity) of the toner to form a transfer electric field between the secondary transfer roll 22 and the back roll 25.

  An intermediate transfer belt cleaner 35 is provided on the downstream side of the secondary transfer portion 20 of the intermediate transfer belt 15 so as to be able to contact with and separate from the intermediate transfer belt 15. The intermediate transfer belt cleaner 35 removes residual toner and paper dust on the intermediate transfer belt 15 after the secondary transfer.

A reference sensor (home position sensor) 42 is disposed upstream of the image forming unit 1Y. The reference sensor 42 generates a reference signal that serves as a reference for taking the image forming timing in each image forming unit. The reference sensor 42 recognizes a mark provided on the back side of the intermediate transfer belt 15 to generate a reference signal, and in response to an instruction from the control unit 40 that has recognized the reference signal, the image forming units 1Y, 1M, 1C, and 1K. Starts image formation.
An image density sensor 43 for adjusting image quality is disposed downstream of the image forming unit 1K.

The image forming apparatus 100 includes a sheet storage unit 50, a sheet feed roll 51, a conveyance roll 52, a conveyance guide 53, a conveyance belt 55, and a fixing entrance guide 56 as conveyance units that convey the sheet K.
The paper storage unit 50 stores paper K before image formation.
The paper feed roll 51 takes out the paper K stored in the paper storage unit 50.
The transport roll 52 transports the paper K taken out by the paper feed roll 51.
The conveyance guide 53 sends the paper K conveyed by the conveyance roll 52 to the secondary transfer unit 20.
The conveyance belt 55 conveys the sheet K on which the image is transferred by the secondary transfer unit 20 to the fixing device 60.
The fixing entrance guide 56 guides the paper K to the fixing device 60.

Next, an image forming method by the image forming apparatus 100 will be described.
In the image forming apparatus 100, image data output from an image reading apparatus (not shown), a computer (not shown), or the like is subjected to image processing by an image processing apparatus (not shown), and then by image forming units 1Y, 1M, 1C, and 1K. Image forming work is executed.

  In the image processing apparatus, the input reflectance data is subjected to image processing such as shading correction, position shift correction, brightness / color space conversion, gamma correction, frame deletion, color editing, and movement editing. 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 the photosensitive members 11 of the image forming units 1Y, 1M, 1C, and 1K with an exposure beam Bm according to the input color material gradation data.
The surface of each of the photoconductors 11 of the image forming units 1Y, 1M, 1C, and 1K is charged by the charger 12, and then the surface is scanned and exposed by the laser exposure device 13 to form an electrostatic latent image. The electrostatic latent image formed on each photoconductor 11 is developed as a toner image of each color by each image forming unit.

  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. Is done. In the primary transfer unit 10, a voltage (primary transfer bias) having a polarity opposite to the toner charging polarity (minus polarity) is applied to the intermediate transfer belt 15 by the primary transfer roll 16, and the toner images are sequentially superimposed on the intermediate transfer belt 15. Transcribed.

The toner image primarily transferred onto the intermediate transfer belt 15 is conveyed to the secondary transfer unit 20 as the intermediate transfer belt 15 moves.
In synchronization with the timing at which the toner image reaches the secondary transfer unit 20, the paper K stored in the paper storage unit 50 is transported by the paper feed roll 51, the transport roll 52 and the transport guide 53, and is transferred to the secondary transfer unit 20. Supplied and sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22.
The toner image on the intermediate transfer belt 15 is electrostatically transferred (secondary transfer) onto the paper K in the secondary transfer unit 20 where the transfer electric field is formed.

The sheet K on which the toner image has been electrostatically transferred is peeled off from the intermediate transfer belt 15 by the secondary transfer roll 22 and conveyed to the fixing device 60 by the conveyance belt 55.
The sheet K conveyed to the fixing device 60 is heated and pressurized by the fixing device 60, and the unfixed toner image is fixed.
Through the above steps, the image forming apparatus 100 suppresses the occurrence of paper wrinkles on the paper K as a recording medium, and forms an image.

  Hereinafter, the present embodiment will be specifically described with reference to examples, but the present embodiment is not limited to the following examples.

<Example 1>
(Production of sliding sheet)
The polyimide precursor was dissolved in an aprotic polar solvent (N-methylpyrrolidone) to prepare a polyimide precursor solution having a solid content of 30% by mass.
The polyimide precursor solution was applied onto a 300 mm × 150 mm aluminum plate with a bar coater (Tester Sangyo Co., Ltd. SA-203-150), dried at 120 ° C. for 60 minutes, and a polyimide precursor with a thickness of 70 μm. A dried coating film (polyimide precursor film) was formed.

3M Glass Bubbles iM16K (average particle size 20 μm, 90% residual pressure strength 110 MPa, thermal conductivity 0.16W) / M · K) A dispersion for forming a sliding layer in which 50 g was dispersed was prepared.
This dispersion is spray-coated on a polyimide precursor film with a thickness of 30 μm, heated to 380 ° C. at a rate of 2 ° C. per minute in a hot air oven, and baked at 380 ° C. for 20 minutes. A sliding sheet having a sliding layer containing PTFE and a glass balloon on the layer was produced.

(Slidability evaluation)
The obtained sliding sheet is set on an A4 color printer DocuPrint C2110 manufactured by Fuji Xerox Co., and the shaft of the fixing roll after passing 50,000 sheets of J paper (color copy paper manufactured by Fuji Xerox Co.) A3 at the initial stage. The torque was measured and the occurrence of paper wrinkles was evaluated. The evaluation of the occurrence of paper wrinkles was made with the number of paper wrinkles occurring for the first time after passing 50,000 sheets.

A: No paper wrinkle occurs B: Paper wrinkle occurs between the 101st sheet and the 50,000th sheet C: Paper wrinkle occurs within the 100th sheet

(Evaluation of thermal insulation)
On the surface (sliding surface) on the PTFE / glass balloon sliding layer side of the obtained sliding sheet, the thermal conductivity is measured by ai-Phase (manufactured by Eye Phase Co., Ltd.), and the heat insulation is evaluated. It was.

<Example 2>
In the dispersion for forming a sliding layer prepared in Example 1, a dispersion for forming a sliding layer was prepared in the same manner as in Example 1 except that the amount of 3M Glass Bubbles iM16K added was 100 g. Coating and baking were performed on the polyimide precursor film to produce a sliding sheet.
Using the obtained sliding sheet, the slidability and heat insulating properties were evaluated in the same manner as in Example 1.

<Example 3>
In the sliding layer forming dispersion prepared in Example 1, the type of glass balloon to be added is 3M Glass Bubbles K37 (average particle size 45 μm, 90% residual pressure strength 21 MPa, thermal conductivity 0.12 W / m · K), and a dispersion for forming a sliding layer was prepared in the same manner as in Example 1 except that the addition amount was 100 g, and applied and baked on the polyimide precursor film to prepare a sliding sheet. .
Using the obtained sliding sheet, the slidability and heat insulating properties were evaluated in the same manner as in Example 1.

<Example 4>
In the dispersion for forming a sliding layer prepared in Example 1, the kind of glass balloon to be added was Spatterel 60P18 (average particle size 18 μm, 90% residual pressure strength 55 MPa, thermal conductivity 0.20 W, manufactured by Potters Ballotini. / M · K), and a dispersion for forming a sliding layer was prepared in the same manner as in Example 1 except that the addition amount was 100 g, and applied and baked on the polyimide precursor film to produce a sliding sheet. did.
Using the obtained sliding sheet, the slidability and heat insulating properties were evaluated in the same manner as in Example 1.

<Example 5>
In the dispersion for forming a sliding layer prepared in Example 1, the type of glass balloon to be added is 3M Glass Bubbles K25 (average particle size 55 μm, 90% residual pressure strength 5 MPa, thermal conductivity 0.09 W / m · K), and a dispersion for forming a sliding layer was prepared in the same manner as in Example 1 except that the addition amount was 100 g, and applied and baked on the polyimide precursor film to prepare a sliding sheet. .
Using the obtained sliding sheet, the slidability and heat insulating properties were evaluated in the same manner as in Example 1.

<Comparative Example 1>
In the sliding layer forming dispersion prepared in Example 1, a sliding layer forming dispersion was prepared and applied onto the polyimide precursor film in the same manner as in Example 1 except that no glass balloon was added. Firing was performed to produce a sliding sheet.
Using the obtained sliding sheet, the slidability and heat insulating properties were evaluated in the same manner as in Example 1.

<Example 6>
In the sliding layer forming dispersion prepared in Example 1, instead of the glass balloon, glass beads EGB210 (average particle size 18 μm, thermal conductivity 0.7 W / m · K) manufactured by Potters Barotini Co., A sliding layer-forming dispersion was prepared in the same manner as in Example 1 except that the amount added was 100 g, and applied and baked on the polyimide precursor film to prepare a sliding sheet.
Using the obtained sliding sheet, the slidability and heat insulating properties were evaluated in the same manner as in Example 1.

On the sliding surface of the sliding sheet produced in the example, convex portions derived from the inorganic material particles added to the sliding layer were observed.
The results are shown in Table 1. In Table 1, “Inorganic material particle addition amount” is an addition amount with respect to 1000 g of PTFE dispersion 31-JR manufactured by Mitsui / DuPont Fluorochemicals.

When the sliding sheet of Comparative Example 1 in which the inorganic material particles are not added to the sliding layer is used, the sliding property is high in the initial torque, and the paper wrinkle is generated at the initial stage of 100 sheets or less. Presence of sliding auxiliary oil was not confirmed on the surface (sliding surface) of the sliding sheet of the sliding portion.
Compared with the case where the sliding sheet of Comparative Example 1 was used, paper wrinkles were less likely to occur when the sliding sheet of the example added with inorganic material particles was used.
Moreover, when the glass balloon with an average particle diameter of 20 micrometers or more was added to the sliding layer, the reduction effect of thermal conductivity was confirmed and the effect with respect to heat insulation was confirmed.

  When the sliding sheet of Example 5 using a glass balloon having an average particle size of 55 μm was used, the initial torque was good, but the torque increased with the passing of paper, and A3 paper and 50,000 sheets were passed. Then, as the torque increased, paper wrinkles were generated, and accumulation of black foreign matter, which was seen as belt abrasion powder, was observed on the sliding surface of the sliding sheet of the sliding portion. As a result of magnifying and observing the surface of the sheet with a microscope, a plurality of dents, which were seen as traces of the added glass balloon breaking, were confirmed. It is considered a thing.

1Y, 1M, 1C, 1K Image forming unit 11 Photoconductor (an example of an image carrier)
12 Charger (Example of charging device)
13 Laser exposure device (an example of a latent image forming apparatus)
14 Developer (Example of developing device)
15 Intermediate transfer belt (part of transfer means)
22 Secondary transfer roll (part of transfer means)
25 Back roll (part of transfer means)
60 Fixing Device 61 Heating Roll (Example of First Rotating Body)
62 Pressure belt (example of sliding member (second rotating body))
64 pressure pad (an example of a pressure member)
65 Support member 66 Halogen lamp (an example of a heating source)
67 Lubricant supply device 80 Fixing device 84 Heating belt (an example of a sliding member (second rotating body))
86 Support member 87 Press pad (an example of a press member)
88 Pressure roll (example of first rotating body)
90 Electromagnetic induction device (an example of a heating source)
100 Image forming apparatus 101 Fusing device sliding member (sliding sheet)
110 Substrate layer 112 Sliding layer 112A Sliding surface 120 Inorganic material particle K Paper (recording medium)

Claims (8)

  A sliding member for a fixing device, comprising a fluororesin and inorganic material particles, and having a convex portion derived from the inorganic material particles on a sliding surface in contact with the sliding member.   The sliding member for a fixing device according to claim 1, wherein the inorganic material particles are hollow particles.   The sliding member for a fixing device according to claim 1, wherein an average particle diameter of the inorganic material particles is 45 μm or less.   The sliding member for a fixing device according to claim 1, wherein the inorganic material particles have an average particle diameter of 20 μm or more.   The sliding member for a fixing device according to claim 1, wherein the sliding member is a sheet shape. A base material layer;
A sliding layer disposed on the substrate layer and having the sliding surface;
The sliding member for a fixing device according to claim 5, comprising: A first rotating body;
A second rotating body disposed in contact with the outer peripheral surface of the first rotating body;
A pressing member that is disposed inside the second rotating body and presses the second rotating body against the first rotating body from an inner peripheral surface of the second rotating body;
The sheet-like fixing device according to claim 5 or 6, wherein the sheet-shaped fixing device is interposed between an inner peripheral surface of the second rotating body and the pressing member, and a sliding surface is in contact with the inner peripheral surface of the second rotating body. Sliding member for
A heating source for heating at least one of the first rotating body and the second rotating body;
A fixing device. An image carrier,
A charging device for charging the surface of the image carrier;
A latent image forming apparatus that forms a latent image on the surface of the charged image carrier;
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 7, wherein the toner image is fixed on a recording medium.
An image forming apparatus comprising: