Film, tubular fixing member, fixing device, and image forming apparatus

Abstract

To provide a film that is excellent in thermal conductivity in a thickness direction.SOLUTION: A film contains at least one high polymer selected from the group consisting of resin and rubber, and conductive filler dispersed in the high polymer and including at least acicular filler. The content of the conductive filler is 40 volume% or more.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a film, a tubular fusing member, a fusing device, and an image forming apparatus. [Background technology]

[0002] In Patent Document 1, "For 100 parts by weight of the polymer component, the thermal conductivity is 5 to 80 W / m K, the volume resistivity is 10 10 Inorganic filler with a resistance of Ω·cm or more: 400-600 parts by weight, thermal conductivity of 100-300 W / m·K, volume resistivity of 10 -3 ~10 -6 A heat dissipating rubber composition is disclosed, which contains 3 to 30 parts by weight of a thermally conductive or electrically conductive filler having a resistivity of Ω·cm and 20 to 40 parts by weight of tetrapod-shaped zinc oxide whiskers.

[0003] Furthermore, Patent Document 2 discloses a resin molded body comprising "a skeletal portion and a resin portion formed integrally with all or part of the skeletal portion, in which the difference in thermal conductivity between the skeletal portion and the resin portion is 1 W / mK or more, and the skeletal portion and / or the resin portion has a volume resistivity of 1 MΩ cm or less (excluding 0)."

[0004] Furthermore, Patent Document 3 discloses "a resin composition containing a thermoplastic resin, carbon fiber, and a conductive filler, the conductive filler being distributed in a network-like manner in the thermoplastic resin." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6438701 [Patent Document 2] Patent No. 3558548 [Patent Document 3] Patent No. 7135825 Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present disclosure is to provide a film that has superior thermal conductivity in the thickness direction compared to a film that does not contain a needle-shaped filler as a conductive filler or a film in which the conductive filler content is less than 40 volume %, as well as a tubular fixing member, a fixing device, and an image forming apparatus that are equipped with the film. [Means for solving the problem]

[0007] Means for solving the above problems include the following aspects. <1> The conductive paste comprises at least one polymer compound selected from the group consisting of resins and rubbers, and a conductive filler including at least a needle-shaped filler dispersed in the polymer compound; A film having a conductive filler content of 40 volume % or more. <2> The volume resistivity at a measurement voltage of 0.1 V is 1,000 ohm cm or less. The applied voltage dependence of volume resistivity, which is the difference between the volume resistivity at a measurement voltage of 0.02 V and the volume resistivity at a measurement voltage of 0.1 V, is 600 ohm cm or less. <1> The film according to claim 1. <3> The applied voltage dependence of volume resistivity, which is the difference between the volume resistivity at a measurement voltage of 0.02 V and the volume resistivity at a measurement voltage of 0.1 V, is 300 ohm cm or less. <2> The film according to claim 1. <4> The applied voltage dependency of surface resistivity, which is the difference between the surface resistivity at a measurement voltage of 0.02 V and the surface resistivity at a measurement voltage of 0.1 V, is 200 ohm / suq. or more. <1> ~ <3> 13. The film according to any one of claims 1 to 12. <5> The applied voltage dependency of surface resistivity, which is the difference between the surface resistivity at a measurement voltage of 0.02 V and the surface resistivity at a measurement voltage of 0.1 V, is 400 ohm / suq. or more. <4> The film according to claim 1. <6> The content of the conductive filler is 60% by volume or more. <1> ~ <5> 13. The film according to any one of claims 1 to 12. <7> The content of the conductive filler is 80% by volume or less. <1> ~ <6> 13. The film according to any one of claims 1 to 12. <8> The content of the conductive filler is 70% by volume or less. <7> The film according to claim 1. <9> The conductive filler further contains at least one of a spherical filler and a flat filler. <1> ~ <8> 13. The film according to any one of claims 1 to 12. <10> The total amount of the spherical filler and the plate-like filler is 20% by volume or more and 60% by volume or less with respect to the total amount of the conductive filler. <9> The film according to claim 1. <11> The total amount of the spherical filler and the plate-like filler is 30% by volume or more and 50% by volume or less with respect to the total amount of the conductive filler. <10> The film according to claim 1. <12> The needle-like filler is a filler of a carbon material. <1> ~ <11> 13. The film according to any one of claims 1 to 12. <13> <1> ~ <12> A tubular fixing member comprising the film according to any one of claims 1 to 5. <14> A first rotating body and a second rotating body arranged in contact with an outer surface of the first rotating body, At least one of the first rotating body and the second rotating body, <13> The tubular fixing member according to claim 1, a fixing device for fixing the toner image by passing a recording medium, on a surface of which a toner image is formed, through a contact portion between the first rotating body and the second rotating body. <15> An image carrier; a charging device for charging the surface of the image carrier; an electrostatic latent image forming device for forming an electrostatic latent image on a charged surface of the image carrier; a developing device for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing a toner to form a toner image; a transfer device for transferring the toner image onto a surface of a recording medium; fixing the toner image onto the recording medium; <14> and the fixing device according to claim 1 . Effect of the Invention

[0008] <1> According to the present invention, a film is provided that has superior thermal conductivity in the thickness direction compared to a film that does not contain a needle-like filler as a conductive filler or a film in which the conductive filler content is less than 40 volume %. <2> or <3> According to the invention, a film is provided that has superior thermal conductivity in the thickness direction compared to a film having a volume resistivity of more than 1,000 ohm cm at a measurement voltage of 0.1 V, or a film having an applied voltage dependence of volume resistivity, which is the difference between the volume resistivity at a measurement voltage of 0.02 V and the volume resistivity at a measurement voltage of 0.1 V, of more than 600 ohm cm. <4> or <5> According to the present invention, a film is provided which has superior thermal conductivity in the thickness direction compared to a film having an applied voltage dependence of surface resistivity, which is the difference between the surface resistivity at a measurement voltage of 0.02 V and the surface resistivity at a measurement voltage of 0.1 V, of less than 200 ohm / suq. <6> According to the present invention, a film is provided which is superior in thermal conductivity in the thickness direction compared to a film having a conductive filler content of less than 60 volume %. <7> or <8> According to the present invention, a film having excellent flexibility and durability is provided as compared with a film having a conductive filler content of more than 80 volume %. <9> According to the present invention, a film is provided which is superior in thermal conductivity in the thickness direction compared to a film which does not contain either a spherical filler or a plate-like filler as a conductive filler. <10> or <11> According to the present invention, a film is provided which has superior thermal conductivity in the thickness direction compared to a film in which the total amount of spherical filler and flat filler is less than 20 volume % of the total amount of conductive filler, or more than 60 volume %. <12> According to the present invention, a film is provided which has superior thermal conductivity in the thickness direction compared to a film in which the needle-shaped filler is a filler made of a ceramic material. <13> , <14> or <15> According to the invention, a tubular fixing member, a fixing device, and an image forming apparatus are provided which have superior image fixing properties compared to films which do not contain needle-shaped filler as a conductive filler, or films in which the conductive filler content is less than 40 volume %. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram illustrating an example of a fixing device according to a first embodiment of the present disclosure. [Diagram 2] FIG. 11 is a schematic configuration diagram illustrating an example of a fixing device according to a second embodiment of the present disclosure. [Diagram 3] 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment that is an example of the present disclosure will be described. These descriptions and examples are intended to illustrate the embodiment, and are not intended to limit the scope of the embodiment.

[0011] In the present disclosure, a numerical range indicated using "~" indicates a range that includes the numerical values ​​before and after "~" as the minimum and maximum values, respectively. In the numerical ranges described in the present disclosure in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In addition, in the numerical ranges described in the present disclosure, the upper or lower limit value of the numerical range may be replaced with a value shown in the examples. In the present disclosure, the term "step" includes not only an independent step, but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved. When an embodiment of the present disclosure is described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. In addition, the size of the members in each drawing is conceptual, and the relative relationship between the sizes of the members is not limited to this. In the present disclosure, each component may contain multiple types of corresponding substances. When referring to the amount of each component in a composition in the present disclosure, if multiple substances corresponding to each component are present in the composition, the total amount of the multiple substances present in the composition is meant unless otherwise specified. In this disclosure, the "axial direction" of a tubular member means the direction in which the axis of rotation of the tubular member extends, and the "circumferential direction" of the tubular member means the direction of rotation of the tubular member.

[0012] <Film> The film according to the embodiment of the present disclosure contains at least one polymer compound selected from the group consisting of resins and rubbers, and a conductive filler including at least a needle-like filler dispersed in the polymer compound, and the conductive filler content is 40% by volume or more.

[0013] The film according to the embodiment of the present disclosure has the above-mentioned configuration and is therefore excellent in thermal conductivity in the thickness direction. The reason for this effect is believed to be as follows.

[0014] The film according to the embodiment of the present disclosure contains a large amount of conductive filler, at least 40% by volume, including needle-like fillers. Therefore, the conductive filler contained in a large amount is present in the polymer compound in a state where it faces in various directions and is randomly dispersed, without being oriented in one direction. It is presumed that the conductive filler is dispersed in a state where it faces in various directions, and thus a thermal conduction path is formed between the conductive fillers in the polymer compound, and excellent thermal conductivity is exhibited in the thickness direction of the film.

[0015] Next, each element constituting the film according to the embodiment of the present disclosure will be described.

[0016] (Conductive filler) Conductive filler content The film according to the embodiment of the present disclosure contains a conductive filler including at least a needle-like filler, and the content of the conductive filler in the film is 40% by volume or more. By having a conductive filler content of 40% by volume or more, a film having excellent thermal conductivity in the thickness direction can be obtained. The content of the conductive filler in the film is preferably 50% by volume or more, and more preferably 60% by volume or more. On the other hand, the lower limit of the conductive filler content in the film is preferably 80% by volume or less, and more preferably 70% by volume or less, from the viewpoint of improving the flexibility and durability of the film.

[0017] Conductive filler shape The film according to the embodiment of the present disclosure contains at least an acicular filler as a conductive filler. By containing at least an elongated acicular filler as the conductive filler contained in the polymer compound in a state of being randomly dispersed in various directions, a good thermal conduction path is formed in the polymer compound, and excellent thermal conductivity is exhibited in the thickness direction of the film.

[0018] In addition to the needle-like filler, the film according to the embodiment of the present disclosure preferably further contains at least one of a spherical filler and a plate-like filler as a conductive filler. By further containing at least one of a spherical filler and a plate-like filler as a conductive filler, a heat conduction path is more easily formed in the polymer compound, and excellent heat conductivity in the thickness direction of the film is easily exhibited.

[0019] When the film contains at least one of spherical fillers and flat fillers, the total amount of the spherical fillers and flat fillers is preferably 20% by volume or more and 60% by volume or less, more preferably 25% by volume or more and 55% by volume or less, and even more preferably 30% by volume or more and 50% by volume or less, of the total amount of conductive fillers, from the viewpoint of making it easier to exhibit excellent thermal conductivity in the thickness direction of the film.

[0020] Here, the shape of the filler will be described. The direction in which the length of one filler is longest is the X-axis, the direction in which the length is longest among the directions perpendicular to the X-axis is the Y-axis, and the direction perpendicular to both the X-axis and the Y-axis is the Z-axis. When the length (z) of the filler on the Z-axis is 1.0, fillers whose length ratios (x:y:z) on the X-axis, Y-axis, and Z-axis are in the following ranges are defined as follows: Needle filler / x:y:z=3.0 or more: less than 3.0, 1.0 or more: 1.0 Flat filler / x:y:z=3.0 or more:3.0 or more:1.0 Spherical filler / x:y:z=less than 3.0, 1.0 or more: less than 3.0, 1.0 or more: 1.0

[0021] How to check the conductive filler content in the film Here, a method for confirming the content of the conductive filler in the film will be described. First, a rectangular parallelepiped with three sides in the axial, circumferential, and thickness directions and a length of 1 mm in the circumferential direction is cut out from the center of the axial direction of the film, and embedded in epoxy resin. The embedded object is cross-sectionally processed with a microtome to form a block cross-section in which the cross-section in the thickness direction can be seen. The sample with the block cross-section formed is fixed to the sample stage of a FIB-SEM device (FIB-SEM Helios NanoLab 600i, FEI Company, USA) and subjected to deposition processing. FIB processing and SEM observation of the block cross-section are repeated with the FIB-SEM device to obtain a two-dimensional stacking image. FIB processing and SEM observation are repeated until at least 30 fillers are observed. SEM observation is performed at a magnification that allows the fillers dispersed in the film to be observed. The two-dimensional stacking images are imported into three-dimensional image analysis software (Avizo-Fire, VSG) to construct a three-dimensional image. From the constructed three-dimensional image, it is confirmed whether the conductive fillers contained are needle-shaped fillers, spherical fillers, or plate-shaped fillers (i.e., the ratio of the lengths of the X-axis, Y-axis, and Z-axis). Furthermore, the individual contents (volume %) of needle-shaped fillers, spherical fillers, and plate-shaped fillers are determined.

[0022] The average fiber length of the needle-like filler, which will be described later, is determined by determining the length of the longest part (X-axis direction) of each needle-like filler from the constructed 3D image and calculating the arithmetic mean of these. Furthermore, the average particle diameter of the spherical filler and the flat filler described below is determined by determining the area circle equivalent diameter of each spherical filler and each flat filler from the constructed 3D image and calculating the arithmetic mean thereof.

[0023] Conductive filler material From the viewpoint of thermal conductivity, the material of the conductive filler is preferably at least one selected from the group consisting of carbon materials, ceramic materials, and metal oxide materials. In particular, from the viewpoint of easily exhibiting excellent thermal conductivity in the thickness direction of the film, the material of the conductive filler is preferably a carbon material, and the material of the needle-shaped filler is more preferably a carbon material.

[0024] Examples of the conductive filler made of a carbon material include carbon fibers such as carbon nanofibers and carbon nanotubes, graphite particles, and tabular graphite. Examples of the conductive filler of the ceramic material include ceramic fibers, ceramic particles, and plate-like ceramics such as aluminum nitride, boron nitride, and silicon carbide. Examples of conductive fillers made of metal oxide materials include acicular metal oxides, metal oxide particles, and plate-like metal oxides, such as alumina, boehmite (alumina monohydrate), silica, titania, zirconia, magnesium oxide, tin oxide, zinc oxide, and barium oxide.

[0025] Conductive filler particle size From the viewpoint of dispersibility in the film, the needle-like filler contained in the film according to an embodiment of the present disclosure preferably has an average fiber length (i.e., the average length of the longest portion (X-axis direction)) of 1 μm or more and 10 μm or less, and more preferably 2 μm or more and 8 μm or less. Furthermore, when the film according to the embodiment of the present disclosure contains at least one of spherical fillers and flat fillers, from the viewpoint of dispersibility in the film, the average particle size of the spherical fillers and flat fillers is preferably 5 μm or more and 20 μm or less, and more preferably 8 μm or more and 18 μm or less.

[0026] (polymer compound) -Types of polymer compounds The film according to the embodiment of the present disclosure contains at least one polymer compound selected from the group consisting of resins and rubbers. Examples of the polymer compound include resins such as polyimide resins, polyamide resins, polyamideimide resins, thermotropic liquid crystal polymers, fluororesins, and silicone resins, and rubbers such as fluororubbers, silicone rubbers, and fluorosilicone rubbers. The polymer compounds may be used alone or in combination of two or more. From the viewpoint of the heat resistance of the film, polyimide resins are preferred.

[0027] The content (vol %) of the polymer compound contained in the film is preferably 20 vol % or more and 60 vol % or less, and more preferably 30 vol % or more and 40 vol % or less, from the viewpoint of flexibility and durability of the film.

[0028] (Film properties) From the viewpoint of exhibiting excellent thermal conductivity in the thickness direction of the film, the film according to the embodiment of the present disclosure preferably has a volume resistivity of 1,000 ohm·cm or less, more preferably 800 ohm·cm or less, and even more preferably 600 ohm·cm or less at a measurement voltage of 0.1 V. The lower limit of the volume resistivity at a measurement voltage of 0.1 V is preferably 100 ohm·cm or more, more preferably 200 ohm·cm or more, and even more preferably 400 ohm·cm or more.

[0029] From the viewpoint of exhibiting excellent thermal conductivity in the thickness direction of the film according to the embodiment of the present disclosure, the applied voltage dependence of the volume resistivity (i.e., the difference between the volume resistivity at a measurement voltage of 0.02 V and the volume resistivity at a measurement voltage of 0.1 V) is preferably 600 ohm·cm or less, more preferably 400 ohm·cm or less, even more preferably 300 ohm·cm or less, and even more preferably 250 ohm·cm or less. Note that the lower limit of the applied voltage dependence of the volume resistivity may be, for example, 0 ohm·cm, 10 ohm·cm or more, or 50 ohm·cm or more.

[0030] From the viewpoint of exhibiting excellent thermal conductivity in the thickness direction of the film according to the embodiment of the present disclosure, the applied voltage dependence of the surface resistivity (i.e., the difference between the surface resistivity at a measurement voltage of 0.02 V and the surface resistivity at a measurement voltage of 0.1 V) is preferably 200 ohm / suq. or more, more preferably 400 ohm / suq. or more, and even more preferably 600 ohm / suq. or more. The upper limit of the applied voltage dependence of the surface resistivity may be, for example, 2,000 ohm / suq. or less, 1,500 ohm / suq. or less, or 1,000 ohm / suq. or less.

[0031] Here, the method for measuring the volume resistivity and surface resistivity of the film will be described. The volume resistivity and surface resistivity are measured at a measurement voltage of 0.1 V and at a measurement voltage of 0.02 V using an R8340A ammeter manufactured by Advantest Corporation and a UR-SS probe as a measurement probe.

[0032] The average thickness of the film according to the embodiment of the present disclosure may be set depending on the application, and may be, for example, 10 μm or more and 1000 μm or less, 15 μm or more and 800 μm or less, or 20 μm or more and 500 μm or less.

[0033] The film according to the embodiment of the present disclosure may be a flat film or a tubular film. Applications of the film according to the embodiment of the present disclosure include sheets installed in electronic devices for the purpose of absorbing and releasing heat, tubular fixing members of image forming devices, etc.

[0034] (Film manufacturing method) An example of a method for producing a film according to an embodiment of the present disclosure is a production method in which the following steps (1) to (3) are carried out in order.

[0035] Step (1): A polymer compound and a conductive filler are mixed to prepare a coating liquid. If necessary, a solvent or a dispersion medium is also mixed. Step (2): The coating liquid is applied onto a substrate and dried to form a coating film. Step (3): The coating is baked to obtain a film.

[0036] By forming the substrate in step (2) into a cylindrical mold, a tubular film can be produced.

[0037] <Tubular fixing member> A tubular anchoring member according to an embodiment of the present disclosure comprises a film according to an embodiment of the present disclosure. The tubular fixing member according to the embodiment of the present disclosure may be a member consisting of only the film according to the embodiment of the present disclosure, a member in which the film according to the embodiment of the present disclosure and another film are laminated, or a member in which a plurality of films according to the embodiment of the present disclosure are laminated. When a plurality of films according to the embodiment of the present disclosure are laminated, the plurality of films may be the same or different in components and compositions.

[0038] The average thickness of the film provided in the tubular fixing member is preferably 20 μm to 300 μm, more preferably 30 μm to 250 μm, and even more preferably 40 μm to 200 μm, from the viewpoints of durability and thermal conductivity.

[0039] The average thickness of the film provided on the tubular fixing member is the arithmetic average of the layer thicknesses measured with an eddy current film thickness gauge at 10 locations evenly spaced along the axial direction of the tubular fixing member and at 90° intervals around the circumferential direction, a total of 40 locations.

[0040] The tubular fixing member according to the embodiment of the present disclosure may have a release layer that serves as an outer peripheral surface on the outer peripheral side of the film according to the embodiment of the present disclosure. The release layer desirably contains a heat-resistant release material. Examples of heat-resistant release materials include fluororesin, polyether ether ketone (PEEK), polyphenylene sulfide (PPS), etc. Examples of fluororesin include tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polyethylene-tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), vinyl fluoride (PVF), etc.

[0041] The release layer may contain various additives, such as fillers (calcium carbonate, etc.), functional fillers (alumina, etc.), softeners (paraffin, etc.), processing aids (stearic acid, etc.), antioxidants (amines, etc.), crosslinking agents, etc.

[0042] The average thickness of the release layer is preferably from 5 μm to 30 μm, more preferably from 10 μm to 25 μm, and even more preferably from 15 μm to 20 μm.

[0043] An example of a tubular fixing member according to an embodiment of the present disclosure includes a configuration in which a base layer, an elastic layer, and a release layer are laminated in this order, and at least one of the base layer and the elastic layer is a film according to an embodiment of the present disclosure. A preferred embodiment of the above embodiment is one in which the base layer is a film according to an embodiment of the present disclosure that contains a resin, and / or one in which the elastic layer is a film according to an embodiment of the present disclosure that contains rubber.

[0044] From the viewpoints of durability and thermal conductivity, the average thickness of the base layer is preferably from 20 μm to 200 μm, more preferably from 30 μm to 150 μm, and even more preferably from 40 μm to 100 μm.

[0045] From the viewpoints of durability and thermal conductivity, the average thickness of the elastic layer is preferably 30 μm or more and 300 μm or less, more preferably 50 μm or more and 250 μm or less, and even more preferably 80 μm or more and 200 μm or less.

[0046] Examples of the shape of the tubular fixing member according to the embodiment of the present disclosure include a cylindrical shape and a belt shape. The tubular fusing member according to the embodiments of the present disclosure may be a fusing belt or a fusing roll.

[0047] <Fixing device> A fixing device according to an embodiment of the present disclosure includes a first rotating body and a second rotating body arranged in contact with the outer surface of the first rotating body, and fixes a recording medium having a toner image formed on its surface to the recording medium by passing the recording medium through a contact portion between the first rotating body and the second rotating body. At least one of the first rotating body and the second rotating body is a rotating body that applies heat to the recording medium, and is a tubular fixing member according to an embodiment of the present disclosure.

[0048] As examples of the fixing device according to the embodiment of the present disclosure, a first embodiment and a second embodiment will be given. The fixing device according to the first embodiment includes a heating roll and a pressure belt, and at least the heating roll is a tubular fixing member according to an embodiment of the present disclosure. The fixing device according to the second embodiment includes a heating belt and a pressure roll, and at least the heating belt is a tubular fixing member according to an embodiment of the present disclosure.

[0049] [First embodiment] FIG. 1 is a schematic diagram showing a fixing device 60 according to the first embodiment. The fixing device 60 includes a heating roll 61 (an example of a first rotating body) and a pressure belt 62 (an example of a second rotating body).

[0050] A halogen lamp 66 (an example of a heating means) is disposed inside the heating roll 61. A temperature sensor 69 is disposed in contact with the surface of the heating roll 61. Based on the temperature measurement value by the temperature sensor 69, the lighting of the halogen lamp 66 is controlled, and the surface temperature of the heating roll 61 is maintained at a target set temperature (for example, 150°C).

[0051] The pressure belt 62 is rotatably supported by a pressure pad 64 and a belt running guide 63 arranged inside.

[0052] The pressure pad 64 presses the pressure belt 62 against the heating roll 61. The pressure belt 62 is pressed against the heating roll 61 by the pressure pad 64, and a pinch region N (nip portion) is formed.

[0053] The pressure pad 64 includes a pinching member 64a and a pinching member 64b. The pinching member 64a is disposed on the entrance side of the pinching region N in order to ensure a wide pinching region N. The pinching member 64b is disposed on the exit side of the pinching region N in order to distort the heating roll 61 and facilitate peeling of the recording medium.

[0054] A sheet-like sliding member 68 is disposed between the pressure pad 64 and the pressure belt 62 in order to reduce the sliding resistance between the inner peripheral surface of the pressure belt 62 and the pressure pad 64. The pressure pad 64 and the sliding member 68 are held by a metallic holding member 65. A belt running guide 63 is attached to the holding member 65. A lubricant supplying device 67, which is a means for supplying a lubricant (oil) to the inner peripheral surface of the pressure belt 62, is attached to the belt running guide 63.

[0055] The peeling member 70 is an auxiliary means for peeling off the recording medium from the fixing device 60, and is disposed downstream of the pinch region N. The peeling member 70 includes a peeling claw 71 and a holding member 72. The peeling claw 71 is held by the holding member 72 at a position adjacent to the heating roll 61.

[0056] The heating roll 61 is rotated by a drive motor (not shown). The heating roll 61 is rotated in the direction of the arrow S by the drive motor, and the pressure belt 62 is rotated in the direction of the arrow R in response to this rotation. Paper K (an example of a recording medium) having an unfixed toner image thereon is guided by a guide 56 and conveyed to a pinch region N, and as the paper K passes through the pinch region N, the toner image on the paper K is fixed by pressure and heat.

[0057] [Second embodiment] FIG. 2 is a schematic diagram showing a fixing device 80 according to the second embodiment. The fixing device 80 includes a fixing belt module 86 having a heating belt 84 (an example of a first rotating body), and a pressure roll 88 (an example of a second rotating body) arranged to be pressed against the heating belt 84 (fixing belt module 86).

[0058] At the contact portion between the heating belt 84 (fixing belt module 86) and the pressure roll 88, a pinch region N (nip portion) is formed.

[0059] The fixing belt module 86 includes a heating belt 84, a heating pressure roll 89, a support roll 90, a support roll 92, a posture correction roll 94, and a support roll 98. The heating belt 84 is wound around the heating pressure roll 89 and the support roll 90. The heating pressure roll 89 is rotated by a drive motor (not shown) and presses the heating belt 84 from its inner circumferential surface toward the pressure roll 88. The support roll 92 is disposed outside the heating belt 84 and defines the rotation path of the heating belt 84. The posture correction roll 94 corrects the posture of the heating belt 84 from the support roll 90 to the heating pressure roll 89, and suppresses meandering of the heating belt 84. The support roll 98 applies tension to the heating belt 84 from its inner circumferential surface on the downstream side of the pinch region N.

[0060] A sheet-like sliding member 82 is disposed between the heating belt 84 and the heating pressure roll 89 in order to reduce the sliding resistance between the inner circumferential surface of the heating belt 84 and the heating pressure roll 89. The sliding member 82 is disposed with both ends supported by support members 96.

[0061] A halogen heater 89A (an example of a heating means) is disposed inside the heating pressure roll 89, and heats the heating belt 84 from the inner circumferential surface side. A halogen heater 90A (an example of a heating means) is disposed inside the support roll 90, and heats the heating belt 84 from the inner circumferential surface side. A halogen heater 92A (an example of a heating means) is disposed inside the support roll 92, and heats the heating belt 84 from the outer circumferential surface side.

[0062] The pressure roll 88 is supported rotatably and is provided so as to be pressed by a biasing means (not shown) against the portion of the heating belt 84 wound around the heating pressure roll 89. The heating belt 84 rotates in the direction of the arrow S due to the rotational drive of the heating pressure roll 89, and the pressure roll 88 rotates in the direction of the arrow R in response to this rotational movement.

[0063] A sheet of paper K (an example of a recording medium) having an unfixed toner image thereon is transported in the direction of arrow P and guided to a pinch region N of the fixing device 80. As the sheet of paper K passes through the pinch region N, the toner image on the sheet of paper K is fixed by pressure and heat.

[0064] <Image forming device> The image forming apparatus according to the embodiment of the present disclosure includes an image carrier, a charging device that charges the surface of the image carrier, an electrostatic latent image forming device that forms an electrostatic latent image on the surface of the charged image carrier, a developing device that develops the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image, a transfer device that transfers the toner image to the surface of a recording medium, and a fixing device according to the embodiment of the present disclosure that fixes the toner image to the recording medium. The fixing device may be a cartridge that is detachable from the image forming apparatus.

[0065] 3 is a schematic diagram showing the configuration of an image forming apparatus 100 according to this embodiment. The image forming apparatus 100 includes the fixing device 60 according to 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.

[0066] 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 that form toner images of each color by electrophotography, a primary transfer section 10 that sequentially transfers (primary transfer) the toner images of each color onto an intermediate transfer belt 15, a secondary transfer section 20 that collectively transfers (secondary transfer) the superimposed toner images transferred onto the intermediate transfer belt 15 onto a recording medium, paper K, a fixing device 60 that fixes the secondary transferred images onto the paper K, and a control section 40 that controls the operation of each device (each section).

[0067] The image forming units 1Y, 1M, 1C, and 1K are arranged in a substantially linear manner from the upstream side of the intermediate transfer belt 15 in the following order: 1Y (yellow unit), 1M (magenta unit), 1C (cyan unit), and 1K (black unit). 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 an arrow A.

[0068] Around the photoconductor 11, a charger 12 (an example of a charging device), a laser exposure device 13 (an example of an electrostatic latent image forming device), a developer 14 (an example of a developing device), a primary transfer roll 16, and a photoconductor cleaner 17 are arranged in sequence along the rotational direction of the photoconductor 11.

[0069] 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 unit 14 contains toner of each color, and develops the electrostatic latent image on the photoconductor 11 into a visible image using the toner. The primary transfer roll 16 transfers the toner image formed on the photoconductor 11 onto the intermediate transfer belt 15 in the primary transfer section 10 . The photoreceptor cleaner 17 removes residual toner from the photoreceptor 11 .

[0070] The intermediate transfer belt 15 is a belt made of a material in which an antistatic agent such as carbon black is added to a resin such as polyimide or polyamide. The intermediate transfer belt 15 has a volume resistivity of, for example, 1×10 6 Ω cm or more 1×10 14 It has a resistance of Ω·cm or less and a thickness of, for example, 0.1 mm.

[0071] The intermediate transfer belt 15 is supported by a drive roll 31 , a support roll 32 , a tensioning roll 33 , a back roll 25 , and a cleaning back roll 34 , and is driven (rotated) in a circular manner in the direction of arrow B as the drive roll 31 rotates. The driving roll 31 is driven by a motor (not shown) having excellent constant speed performance to rotate the intermediate transfer belt 15 . The support roll 32 , together with the drive roll 31 , supports the intermediate transfer belt 15 , which extends in a substantially straight line along the arrangement direction of the four photoconductors 11 . The tension applying roll 33 applies a constant tension to the intermediate transfer belt 15 and also functions as a correction roll for suppressing meandering of the intermediate transfer belt 15 . The back roll 25 is provided in the secondary transfer section 20 , and the cleaning back roll 34 is provided in a cleaning section that scrapes off residual toner on the intermediate transfer belt 15 .

[0072] The primary transfer roll 16 is disposed in pressure contact with the photoconductor 11 with the intermediate transfer belt 15 sandwiched therebetween, forming the primary transfer section 10 . A voltage (primary transfer bias) of the opposite polarity to the charge polarity of the toner (negative polarity; the same applies below) is applied to the primary transfer roll 16. As a result, the toner images on the photoconductors 11 are electrostatically attracted to the intermediate transfer belt 15 in sequence, and superimposed toner images are formed on the intermediate transfer belt 15. The primary transfer roll 16 is a cylindrical roll that is composed of a shaft (e.g., a cylindrical rod of metal such as iron or SUS) and an elastic layer (e.g., a sponge layer of blended rubber containing a conductive agent such as carbon black) fixed to the periphery of the shaft. The primary transfer roll 16 has a volume resistivity of, for example, 1×10 7.5 Ω cm or more 1×10 8.5 Ω·cm or less.

[0073] The secondary transfer roll 22 is disposed in pressure contact with the back roll 25 with the intermediate transfer belt 15 sandwiched therebetween, forming a secondary transfer section 20 . The secondary transfer roll 22 forms a secondary transfer bias between itself and the back roll 25, and performs second transfer of the toner image onto the paper K (recording medium) conveyed to the secondary transfer unit 20. The secondary transfer roll 22 is a cylindrical roll that is composed of a shaft (e.g., a cylindrical rod of metal such as iron or SUS) and an elastic layer (e.g., a sponge layer of blended rubber containing a conductive agent such as carbon black) that is fixed to the periphery of the shaft. The secondary transfer roll 22 has a volume resistivity of, for example, 1×10 7.5 Ω cm or more 1×10 8.5 Ω·cm or less.

[0074] The back roll 25 is disposed on the back side of the intermediate transfer belt 15 and constitutes a counter electrode for the secondary transfer roll 22 , forming a transfer electric field between itself and the secondary transfer roll 22 . The back roll 25 is formed by, for example, covering a rubber base material with a tube of blended rubber in which carbon is dispersed. The back roll 25 has a surface resistivity of, for example, 1×10 7 Ω / □ or more 1×10 10 It has a hardness of, for example, 70° (Asker C: manufactured by Kobunshi Keiki Co., Ltd.; the same applies below). A metallic power supply roll 26 is arranged in contact with the back roll 25. The power supply roll 26 applies a voltage (secondary transfer bias) of the same polarity as the charge polarity (negative polarity) of the toner, and forms a transfer electric field between the secondary transfer roll 22 and the back roll 25.

[0075] An intermediate transfer belt cleaner 35 is provided on the intermediate transfer belt 15 downstream of the secondary transfer unit 20 so as to be movable toward and away from the intermediate transfer belt 15. The intermediate transfer belt cleaner 35 removes residual toner and paper dust from the intermediate transfer belt 15 after the secondary transfer.

[0076] 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 timing image formation in each image forming unit. The reference sensor 42 recognizes a mark provided on the back side of the intermediate transfer belt 15 and generates a reference signal. Upon recognition of this reference signal, the control unit 40 issues an instruction to the image forming units 1Y, 1M, 1C, and 1K to start image formation. An image density sensor 43 for adjusting image quality is disposed downstream of the image forming unit 1K.

[0077] The image forming apparatus 100 includes, as transport means for transporting the paper K, a paper storage unit 50, a paper feed roll 51, a transport roll 52, a transport guide 53, a transport belt 55, and a fixing entrance guide 56. The paper storage section 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 picked up by the paper feed roll 51. The transport guide 53 sends the paper K transported by the transport roll 52 to the secondary transfer unit 20 . The conveyor belt 55 conveys the paper K onto which the image has been 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 .

[0078] An image forming method using the image forming apparatus 100 will be described. In the image forming apparatus 100, image data output from an image reading device (not shown) or a computer (not shown) is processed by an image processing device (not shown), and an image forming operation is carried out by image forming units 1Y, 1M, 1C, and 1K.

[0079] The image processing device performs image processing such as shading correction, positional deviation correction, brightness / color space conversion, gamma correction, frame erasure, color editing, movement editing, etc. The image data that has undergone image processing is converted into color material gradation data of four colors, Y, M, C, and K, and is output to the laser exposure device 13.

[0080] The laser exposure device 13 irradiates the exposure beam Bm onto each of the photoconductors 11 of the image forming units 1Y, 1M, 1C, and 1K in accordance with the input color material gradation data. The surface of each photoconductor 11 in the image forming units 1Y, 1M, 1C, and 1K is charged by a charger 12, and then the surface is scanned and exposed by a laser exposure device 13 to form an electrostatic latent image. The electrostatic latent image formed on each photoconductor 11 is developed into a toner image of each color by each image forming unit.

[0081] 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 section 10 where the photoconductors 11 and the intermediate transfer belt 15 come into contact with each other. In the primary transfer section 10, a voltage (primary transfer bias) of the opposite polarity to the charge polarity (negative polarity) of the toner is applied to the intermediate transfer belt 15 by the primary transfer roll 16, and the toner images are transferred onto the intermediate transfer belt 15 in sequence, overlapping each other.

[0082] The toner image that has been primarily transferred onto the intermediate transfer belt 15 is transported to a 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 section 20, the paper K stored in the paper storage section 50 is transported by the paper feed roll 51, the transport roll 52 and the transport guide 53, supplied to the secondary transfer section 20, and sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. Then, in the secondary transfer section 20 where a transfer electric field is formed, the toner image on the intermediate transfer belt 15 is electrostatically transferred (secondarily transferred) onto the paper K.

[0083] The paper K onto which the toner image has been electrostatically transferred is peeled off from the intermediate transfer belt 15 by the secondary transfer roll 22 and is transported to the fixing device 60 by the transport belt 55 . The paper K conveyed to the fixing device 60 is heated and pressed by the fixing device 60, so that the unfixed toner image is fixed thereon. Through the above steps, an image is formed on the recording medium by the image forming apparatus 100. EXAMPLES

[0084] Hereinafter, the embodiments of the present invention will be described in detail with reference to examples, but the embodiments of the present invention are in no way limited to these examples. In the following description, unless otherwise specified, "parts" and "%" are by mass. In the following description, syntheses, treatments, manufactures, etc. were carried out at room temperature (25° C.±3° C.) unless otherwise specified.

[0085] <Film manufacturing> [Example 1] A polyamic acid solution (solid content 18%, U-imide varnish KX-R, manufactured by Unitika Co., Ltd.), needle-shaped filler 1 (carbon nanotube), and plate-shaped filler 1 (graphite) were mixed and kneaded with a three-roll mill to prepare coating solution (1). The total content (volume %) of the conductive filler and the ratio (volume %) of needle-shaped filler 1 and plate-shaped filler 1 in the conductive filler are shown in Table 1. The dispersion state of the conductive filler in the coating solution was controlled by adjusting the distance between the roll mills and the rotation speed of the roll mills when kneading the polyamic acid solution and the conductive filler.

[0086] The coating solution (1) was applied onto the outer peripheral surface of an aluminum cylindrical mold (diameter 168 mm). During application of the coating solution, the dispersion state of the conductive filler in the coating film was controlled by adjusting the gap between the flat plate and the film applicator and the application speed (mm / s). The cylindrical mold with the coating film was then placed in a heating furnace and heated to a temperature of 320° C. to bake the film. The amount of coating solution (1) was adjusted so that the average thickness of the film was 80 μm. The cylindrical mold under the film was pulled out to obtain a tubular film.

[0087] [Examples 2 to 6, 8] A film was obtained in the same manner as in Example 1, except that the conductive filler used was changed to Filler A and Filler B shown in Table 1, and the total content (volume %) of the conductive filler and the proportion (volume %) of Filler A and Filler B in the conductive filler were changed to the values ​​shown in Table 1.

[0088] [Example 7] A film was obtained in the same manner as in Example 1, except that the conductive filler used was changed to Filler A shown in Table 1, and the total conductive filler content (volume %) was changed to the value shown in Table 1.

[0089] [Comparative Examples 1 to 4] A film was obtained in the same manner as in Example 1, except that the conductive filler used was changed to Filler A shown in Table 1, and the total conductive filler content (volume %) was changed to the value shown in Table 1. In Comparative Example 3, when mixing the polyamic acid solution and the conductive filler, the distance between the roll mills was adjusted to be narrower than in Example 1, and the rotation speed of the roll mill was adjusted to be faster than in Example 1. Furthermore, when applying the coating solution, the gap between the flat plate and the film applicator was adjusted to be narrower than in Example 1, and the application speed (mm / s) was adjusted to be faster than in Example 1.

[0090] <Confirmation of conductive filler content in film> The conductive filler content of the films obtained in the examples and comparative examples was confirmed. A rectangular parallelepiped with three sides in the axial, circumferential, and thickness directions and a length of 1 mm in the circumferential direction was cut out from the center of the axial direction of the film and embedded in epoxy resin. The embedded object was cross-sectionally processed with a microtome to form a block cross-section in which the cross-section in the thickness direction can be seen. The sample with the block cross-section formed was fixed on the sample stage of a FIB-SEM device (FIB-SEM Helios NanoLab 600i, FEI Company, USA) and subjected to deposition processing. FIB processing and SEM observation of the block cross-section were repeated using the FIB-SEM device to obtain a two-dimensional stacking image. FIB processing and SEM observation were repeated until at least 30 fillers were observed. SEM observation was performed at a magnification that allowed the fillers dispersed in the film to be observed. The two-dimensional stacking images were imported into three-dimensional image analysis software (Avizo-Fire, VSG) to construct a three-dimensional image. From the constructed three-dimensional image, it was confirmed whether the conductive fillers contained were needle-shaped fillers, spherical fillers, or plate-shaped fillers (i.e., the ratio of the lengths on the X-axis, Y-axis, and Z-axis). Furthermore, the individual contents (volume %) of needle-shaped fillers, spherical fillers, and plate-shaped fillers were determined.

[0091] <Film properties> The volume resistivity and surface resistivity of the films obtained in the examples and comparative examples were measured. Using an Advantest R8340A ammeter and a UR-SS probe as the measurement probe, the volume resistivity (ohm cm) was measured at a measurement voltage of 0.1 V and at a measurement voltage of 0.02 V, and the surface resistivity (ohm / suq.) was measured at a measurement voltage of 0.1 V and at a measurement voltage of 0.02 V. The measurement results are shown in Table 2. Table 2 also shows the applied voltage dependence of the volume resistivity (i.e., the difference between the volume resistivity at a measurement voltage of 0.02 V and the volume resistivity at a measurement voltage of 0.1 V) and the applied voltage dependence of the surface resistivity (i.e., the difference between the surface resistivity at a measurement voltage of 0.02 V and the surface resistivity at a measurement voltage of 0.1 V).

[0092] <Thermal conductivity of film> The film was cut into a square of 2 mm in the axial direction and 2 mm in the circumferential direction, which was used as the measurement sample. Thermal diffusivity was measured at room temperature (25°C ± 3°C) using a thermal diffusivity measuring device ai-phase (manufactured by ai-phase Co., Ltd.), and thermal conductivity (W / (m K)) was calculated by multiplying the thermal diffusivity by the specific heat and density. The calculated thermal conductivity was classified as follows: A(◎): 10W / (m·K) or more B(〇): 7.0W / (m K) or more, less than 10W / (m K) C(×): Less than 7.0W / (m K)

[0093] [Table 1]

[0094] [Table 2]

[0095] The details of each filler listed in Table 1 are as follows. (Needle filler) Needle-shaped filler 1 / Carbon nanotube, Product name: VGCF-H, Manufacturer: Resonac, Average fiber length 4μm (Flat filler) Flat filler 1 / graphite, product name: UP-15N, manufacturer: Nippon Graphite Co., Ltd., average particle size 15 μm Flat filler 2 / Graphene nanoplatelets, Product name: GNZ-XC, Manufacturer: Graphene Platform (Spherical filler) Spherical filler 1 / spherical graphite, product name: CGB-12R, manufacturer: Nippon Graphite Co., Ltd., average particle size 12 μm Spherical filler 2 / Product name: Denka Black, Manufacturer: Denka Spherical filler 3 / Product name: Speciel Black 4, Manufacturer: Orion Engineered Carbons

[0096] The film, tubular fixing member, fixing device, and image forming apparatus according to the embodiments of the present disclosure include the following aspects. (((1))) The conductive paste comprises at least one polymer compound selected from the group consisting of resins and rubbers, and a conductive filler including at least a needle-shaped filler dispersed in the polymer compound; A film having a conductive filler content of 40 volume % or more. (((2))) The volume resistivity at a measurement voltage of 0.1 V is 1,000 ohm cm or less. The film according to (((1))), wherein the applied voltage dependence of volume resistivity, which is the difference between the volume resistivity at a measurement voltage of 0.02 V and the volume resistivity at a measurement voltage of 0.1 V, is 600 ohm cm or less. (((3))) The film according to (((2))), wherein the applied voltage dependence of volume resistivity, which is the difference between the volume resistivity at a measurement voltage of 0.02 V and the volume resistivity at a measurement voltage of 0.1 V, is 300 ohm cm or less. (((4))) The film according to any one of (((1))) to (((3))), having an applied voltage dependency of surface resistivity, which is the difference between the surface resistivity at a measurement voltage of 0.02 V and the surface resistivity at a measurement voltage of 0.1 V, of 200 ohm / suq. or more. (((5))) The film according to (((4))), having an applied voltage dependency of surface resistivity, which is the difference between the surface resistivity at a measurement voltage of 0.02 V and the surface resistivity at a measurement voltage of 0.1 V, of 400 ohm / suq. or more. (((6))) The film according to any one of (((1))) to (((5))), wherein the conductive filler content is 60 volume % or more. (((7))) The film according to any one of (((1))) to (((6))), wherein the conductive filler content is 80 volume % or less. (((8))) The film according to (((7))), wherein the conductive filler content is 70 volume % or less. (((9))) The film according to any one of (((1))) to (((8))), further comprising at least one of a spherical filler and a plate-like filler as the conductive filler. (((10))) The film according to (((9))), wherein the total amount of the spherical filler and the plate-like filler is 20% by volume or more and 60% by volume or less with respect to the total amount of the conductive filler. (((11))) The film according to (((10))), wherein the total amount of the spherical filler and the plate-like filler is 30 volume % or more and 50 volume % or less with respect to the total amount of the conductive filler. (((12))) The film according to any one of ((1))) to (((11))), wherein the needle-like filler is a filler made of a carbon material. (((13))) A tubular fixing member comprising the film according to any one of (((1))) to (((12))). (((14))) A first rotating body and a second rotating body arranged in contact with an outer surface of the first rotating body, At least one of the first rotating body and the second rotating body is a tubular fixing member described in (((13))), a fixing device for fixing the toner image by passing a recording medium, on a surface of which a toner image is formed, through a contact portion between the first rotating body and the second rotating body. (((15))) An image carrier; a charging device for charging the surface of the image carrier; an electrostatic latent image forming device for forming an electrostatic latent image on a charged surface of the image carrier; a developing device for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing a toner to form a toner image; a transfer device for transferring the toner image onto a surface of a recording medium; and a fixing device according to (((14))) that fixes the toner image onto the recording medium.

[0097] According to the invention (((1))), a film is provided which has superior thermal conductivity in the thickness direction compared to a film which does not contain a needle-like filler as a conductive filler or a film in which the conductive filler content is less than 40 volume %. According to the invention of (((2))) or (((3))), a film is provided which has superior thermal conductivity in the thickness direction compared to a film having a volume resistivity of more than 1,000 ohm cm at a measurement voltage of 0.1 V, or a film having an applied voltage dependence of volume resistivity, which is the difference between the volume resistivity at a measurement voltage of 0.02 V and the volume resistivity at a measurement voltage of 0.1 V, of more than 600 ohm cm. According to the invention of (((4))) or (((5))), a film is provided which has superior thermal conductivity in the thickness direction compared to a film having an applied voltage dependence of surface resistivity, which is the difference between the surface resistivity at a measurement voltage of 0.02 V and the surface resistivity at a measurement voltage of 0.1 V, of less than 200 ohm / suq. According to the invention related to (((6))), a film is provided which has superior thermal conductivity in the thickness direction compared to a film having a conductive filler content of less than 60 volume %. According to the invention related to (((7))) or (((8))), a film having superior flexibility and durability is provided compared to a film having a conductive filler content of more than 80 volume %. According to the invention (((9))), a film is provided which has superior thermal conductivity in the thickness direction compared to a film which does not contain either a spherical filler or a flat filler as a conductive filler. According to the invention of (((10))) or (((11))), a film is provided which has superior thermal conductivity in the thickness direction compared to a film in which the total amount of spherical filler and flat filler is less than 20 volume % or more than 60 volume % of the total amount of conductive filler. According to the invention (((12))), a film is provided which has superior thermal conductivity in the thickness direction compared to a film in which the needle-shaped filler is a filler made of a ceramic material. According to the invention related to (((13))), (((14))) or (((15))), there are provided a tubular fixing member, a fixing device, and an image forming apparatus which have superior image fixing properties compared to a film which does not contain a needle-like filler as a conductive filler, or a film in which the conductive filler content is less than 40 volume %. [Explanation of symbols]

[0098] 60 Fixing device 61 Heating Roll 62 Pressure Belt 63 Belt guide 64 Pressure Pad 64a Clamping member 64b Clamping member 65 Retaining member 66 Halogen lamp 67 Lubricant supply device 68 Sliding members 69 Thermosensor 70 Peeling member 71 Peeling Claw 72 Retaining member 80 Fixing device 82 Sliding member 84 Heating Belt 86 Fuser Belt Module 88 Pressure Roll 89 Heated pressure roll 89A halogen heater 90 Support Roll 90A halogen heater 92 Support Roll 92A halogen heater 94 Posture Correction Roll 96 Support member 98 Support Roll 100 Image forming device 1Y, 1M, 1C, 1K Image forming unit 11 Photoconductor (an example of an image carrier) 12 Charger (an example of a charging device) 13 Laser exposure device (an example of an electrostatic latent image forming device) 14 Developing unit (an example of a developing device) 15 Intermediate transfer belt 16 Primary transfer roll (an example of a transfer device) 22 Secondary transfer roll (an example of a transfer device) K Paper (an example of a recording medium)

Claims

1. The conductive paste comprises at least one polymer compound selected from the group consisting of resins and rubbers, and a conductive filler including at least a needle-shaped filler dispersed in the polymer compound; A film having a conductive filler content of 40 volume % or more.

2. The volume resistivity at a measurement voltage of 0.1 V is 1,000 ohm cm or less, 2. The film according to claim 1, wherein the applied voltage dependence of volume resistivity, which is the difference between the volume resistivity at a measurement voltage of 0.02 V and the volume resistivity at a measurement voltage of 0.1 V, is 600 ohm-cm or less.

3. 3. The film according to claim 2, wherein the applied voltage dependence of volume resistivity, which is the difference between the volume resistivity at a measurement voltage of 0.02 V and the volume resistivity at a measurement voltage of 0.1 V, is 300 ohm-cm or less.

4. 2. The film according to claim 1, wherein the applied voltage dependence of the surface resistivity, which is the difference between the surface resistivity at a measurement voltage of 0.02 V and the surface resistivity at a measurement voltage of 0.1 V, is 200 ohm / seq. or more.

5. 5. The film according to claim 4, wherein the applied voltage dependency of the surface resistivity, which is the difference between the surface resistivity at a measurement voltage of 0.02 V and the surface resistivity at a measurement voltage of 0.1 V, is 400 ohm / seq. or more.

6. The film according to claim 1 , wherein the conductive filler content is 60% by volume or more.

7. The film according to claim 1 , wherein the conductive filler content is 80% by volume or less.

8. The film according to claim 7 , wherein the conductive filler content is 70% by volume or less.

9. The film according to claim 1 , further comprising at least one of a spherical filler and a flat filler as the conductive filler.

10. The film according to claim 9 , wherein the total amount of the spherical filler and the plate-like filler is 20% by volume or more and 60% by volume or less with respect to the total amount of the conductive filler.

11. The film according to claim 10 , wherein the total amount of the spherical filler and the plate-like filler is 30% by volume or more and 50% by volume or less with respect to the total amount of the conductive filler.

12. 2. The film according to claim 1, wherein the acicular filler is a filler of a carbon material.

13. A tubular fusing member comprising the film according to any one of claims 1 to 12.

14. A first rotating body and a second rotating body arranged in contact with an outer surface of the first rotating body, At least one of the first rotating body and the second rotating body is the tubular fixing member according to claim 13 , a fixing device for fixing the toner image by passing a recording medium, on a surface of which a toner image is formed, through a contact portion between the first rotating body and the second rotating body;

15. An image carrier; a charging device for charging the surface of the image carrier; an electrostatic latent image forming device for forming an electrostatic latent image on a charged surface of the image carrier; a developing device for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing a toner to form a toner image; a transfer device for transferring the toner image onto a surface of a recording medium; An image forming apparatus comprising: the fixing device according to claim 14 which fixes the toner image onto the recording medium.

Images