Fusing belt

Abstract

The present invention aims to provide a fixing belt having excellent thermal conductivity and capable of suppressing the increase of torque during long-term use. The fixing belt of the present invention comprises a base layer including a polyimide resin, a thermal conductive filler and a wear-resistant filler, wherein the wear-resistant filler has an old Mohs hardness of 5 or more, the base layer has a thermal conductivity of 0.7 W / mK or more, and the inner surface roughness Rz of the base layer in the sliding direction is 2.0 μm or less.

Description

Technical Field

[0001] The present invention relates to a fixing belt mounted on an image forming apparatus or the like. Background Art

[0002] In image forming apparatuses such as copiers and printers using an electrophotographic method, an unfixed toner image formed on a recording medium such as recording paper is fixed by a fixing device. In the fixing device of such an image forming apparatus, a transfer paper having a thermosensitive ink temporarily disposed on one surface of a fixing belt is fed between a fixing belt having a heater disposed on the back side and a pressure roller, so that the thermosensitive ink is melted and fixed on the transfer paper and pressure is applied to the thermosensitive ink so that the thermosensitive ink is firmly fixed.

[0003] Meanwhile, a method is known in which a filler with excellent thermal conductivity (high thermal conductivity filler) is included in the base material layer of the fixing belt, so as to improve the thermal conductivity of the fixing belt, enhance the fixing performance, and achieve a shortened waiting time after startup, a reduced power consumption, and a high fixing speed, etc. For example, as such a method, "mixing 1 to 25 parts by volume of a filler with a thermal conductivity greater than 60 W / mk in a resin tubular material with a heat-resistant resin as a base material" has been proposed in the past (for example, see Japanese Patent Application Laid-Open No. 2006-330405).

[0004] Prior art literature

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-330405 Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] However, when such a high thermal conductivity filler is used to make a substrate, for applications requiring increased printing speed, the following problems may occur when used for a long time: the substrate itself may be scraped by the guide portion of the heater, and the scraps of the substrate may be mixed into the grease provided on the inner surface of the fixing belt, deteriorating the function of the grease, and increasing the torque of the fixing belt. Therefore, a fixing belt is required that can suppress the increase in torque caused by scraping of the substrate while maintaining thermal conductivity.

[0009] An object of the present invention is to provide a fixing belt which has excellent thermal conductivity and can suppress an increase in torque during long-term use.

[0010] Technical means to solve technical problems

[0011] The fixing belt of the present invention comprises at least a polyimide resin, a thermally conductive filler and an abrasion-resistant filler in the base layer. The thermally conductive filler can control the thermal conductivity of the base layer to be above 0.7 W / mK, and the old Mohs hardness of the abrasion-resistant filler is above 5. Moreover, the base layer obtained by these is not easily scraped and can maintain the function of the grease. In addition, the inner surface roughness Rz of the base layer in the sliding direction is below 2.0 μm.

[0012] In the fixing belt of the present invention, the diameter (particle size) of the wear resistant filler is preferably in the range of 0.1 μm to 10 μm, and the amount of the wear resistant filler added to the base layer is preferably in the range of 0.1 parts by volume to 10 parts by volume.

[0013] In the fixing belt of the present invention, the shape of the wear-resistant filler is preferably any of a plate shape, a needle shape, and a spherical shape.

[0014] In the fixing belt of the present invention, the diameter (particle size) of the thermally conductive filler is preferably in the range of 0.1 μm to 10 μm, and the amount of the thermally conductive filler added is preferably in the range of 5 parts by volume to 50 parts by volume.

[0015] In the fixing belt of the present invention, the wear-resistant filler preferably has an old Mohs hardness within a range of 5 or more and 9 or less.

[0016] In the fixing belt of the present invention, the thermal conductivity of the base material layer is preferably within a range of 0.7 W / mK to 2.5 W / mK.

[0017] In the fixing belt of the present invention, it is preferable that the inner surface roughness Rz of the base material layer in the sliding direction is within a range of 0.3 μm or more and 2.0 μm or less.

[0018] In the fixing belt of the present invention, the elongation of the base material layer is preferably within a range of 2% to 20%.

[0019] In the fixing belt of the present invention, the puncture strength of the base material layer is preferably within a range of 0.9 kgf to 2.0 kgf.

[0020] Effects of the Invention

[0021] The fixing belt of the present invention described above is excellent in thermal conductivity and can suppress an increase in torque during long-term use. DETAILED DESCRIPTION

[0022] The fixing belt in the embodiment of the present invention has a base layer including a polyimide resin, a thermally conductive filler and an abrasion resistant filler, wherein the abrasion resistant filler has an old Mohs hardness of 5 or more, a thermal conductivity of the base layer of 0.7 W / mK or more, and an inner surface roughness Rz of the base layer in a sliding direction of 2.0 μm or less.

[0023] In addition, the fixing belt of the present embodiment is preferably an endless belt.

[0024] The fixing belt of the present embodiment has the above-mentioned structure, so that the thermal conductivity is high, and thus the inner surface of the belt can be suppressed from being scraped, thereby preventing the torque from increasing.

[0025] The reason for this can be presumed as follows.

[0026] In the fixing belt of the present embodiment, while the thermal conductivity is improved by the thermal conductive filler, the old Mohs hardness of the wear-resistant filler is 5 or more, so that the scraping of the substrate caused by the wear-resistant filler on the inner side is suppressed, and the torque increase caused by the scraping of the substrate can be suppressed. Therefore, the old Mohs hardness is more preferably in the range of 5 or more and 9 or less, and more preferably in the range of 6 or more and 9 or less. In addition, it is believed that since the inner surface roughness Rz in the sliding direction of the substrate layer is 2.0 μm or less, the friction force of the heater guide relative to the substrate layer can be reduced, and the scraping of the substrate layer can be further suppressed. In addition, by optimizing the inner surface roughness Rz along the sliding direction of the fixing belt (the rotation direction of the fixing belt), the friction force of the fixing belt relative to the heater guide can be further reduced. Here, such an inner surface roughness Rz is preferably 1.7 μm or less, and more preferably 1.5 μm or less. In addition, the inner surface roughness Rz is preferably 0.3 μm or more, more preferably 0.4 μm or more, and more preferably 0.5 μm or more.

[0027] The thermal conductivity of the base layer of the fixing belt of this embodiment is preferably 0.7 W / mK or more, which can increase the fixing speed of the fixing device. It is more preferably 0.7 W / mK or more and 2.5 W / mK or less, further preferably 0.9 W / mK or more and 2.5 W / mK or less, and further preferably 1.0 W / mK or more and 2.2 W / mK or less.

[0028] As a thermally conductive filler, graphite, boron nitride, carbon nanotubes, etc. can be used. In addition, since the thermally conductive filler has high thermal conductivity with a small amount of addition, it is preferably in a plate or needle shape. Further, as the diameter (particle size) of the thermally conductive filler, it is preferably in the range of 0.1 μm or more and 10 μm or less, more preferably in the range of 1 μm or more and 10 μm or less, and further preferably in the range of 2 μm or more and 8 μm or less. The diameter (particle size) here is the longest diameter in the case of a needle shape or a plate shape.

[0029] Furthermore, the wear-resistant filler with an old Mohs hardness of 5 or more used in the present embodiment is preferably an inorganic particle, such as silicon oxide (fused silica), magnesium oxide, titanium oxide, crystalline silicon dioxide, silicon carbide, aluminum nitride, fused silica, silicon nitride, aluminum oxide (aluminum oxide), beryllium oxide, aluminum oxide (alumina), etc. In addition, these wear-resistant fillers are preferably spherical, plate-like, or needle-like in shape. Further, in terms of controlling the dispersibility and the inner surface roughness of the substrate layer, the diameter (particle size) of the wear-resistant filler is preferably within the range of 0.1 μm or more and 10 μm or less. In addition, the diameter (particle size) of the wear-resistant filler is preferably within the range of 0.2 μm or more and 10 μm or less, more preferably within the range of 0.2 μm or more and 7 μm or less, and further preferably within the range of 0.2 μm or more and 5 μm or less. Furthermore, if the wear-resistant filler is in the shape of a plate, needle, or sphere, it can make the substrate layer difficult to scrape. Therefore, the wear-resistant filler is preferably in such a shape. In addition, even if the wear-resistant filler is in the above-mentioned shape, the degree of difficulty in scraping the substrate layer varies depending on the shape of the wear-resistant filler, and the preferred diameter (particle size) also varies due to its shape. In the case where the wear-resistant filler is in the shape of a plate or needle, since the wear-resistant filler is easily oriented on the surface of the substrate layer, even if the diameter is large, the surface of the substrate layer is difficult to become rough, and the substrate layer is also difficult to be scraped. That is, when using a plate-shaped or needle-shaped wear-resistant filler, a wear-resistant filler with a large diameter tends to be selected. However, if the diameter is too large, it is difficult to maintain the mechanical properties required as a fixing belt, so it is not preferred. Based on these circumstances, the diameter of the plate-shaped wear-resistant filler is preferably in the range of 0.1 μm or more and 10 μm or less, and the diameter of the needle-shaped wear-resistant filler is preferably in the range of 0.1 μm or more and 7 μm or less. On the other hand, when the wear-resistant filler is spherical, the surface of the substrate layer tends to become rough as the diameter of the wear-resistant filler increases, and the substrate layer tends to be scraped. That is, when a spherical wear-resistant filler is used, it is preferred to reduce the diameter of the wear-resistant filler. Specifically, the diameter of the spherical wear-resistant filler is preferably within a range of 0.1 μm or more and 5 μm or less.

[0030] In addition, the elongation of the base layer of the fixing belt of the present embodiment is preferably within the range of 2% to 20%, more preferably within the range of 3% to 20%, and further preferably within the range of 5% to 20%. By setting the elongation within the range of 2% to 20%, the bending property is excellent.

[0031] In addition, the puncture strength of the base material layer of the fixing belt of the present embodiment is preferably within the range of 0.9 kgf to 2.0 kgf, more preferably within the range of 1.0 kgf to 1.7 kgf, and further preferably within the range of 1.1 kgf to 1.4 kgf. By setting the puncture strength of the base material layer within the range of 0.9 kgf to 2.0 kgf, the fixing belt is excellent in mechanical properties.

[0032] Then, as the polyimide resin for forming the fixing belt of the present embodiment, for example, a polymer of tetracarboxylic dianhydride and a diamine compound, i.e., an imide of polyamic acid (polyamic acid, polyamic acid) can be cited. As the polyimide resin, a material obtained by polymerizing equimolar amounts of tetracarboxylic dianhydride and a diamine compound in a solvent to obtain a polyamic acid solution is specifically cited, and the polyamic acid is imidized.

[0033] Specific examples of tetracarboxylic dianhydrides include pyromellitic dianhydride (PMDA), 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3,3'4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 2,3,3'-biphenyltetracarboxylic dianhydride, 2,3' ... 3,3',4'-Benzophenonetetracarboxylic dianhydride, 3,3',4,4'-Benzophenonetetracarboxylic dianhydride (BTDA), bis(3,4-dicarboxyphenyl)sulfone dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 2,2-bis[3,4-(dicarboxyphenyloxy) )phenyl]propane dianhydride (BPADA), 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, oxydiphthalic anhydride (ODPA), bis(3,4-dicarboxyphenyl) sulfone dianhydride, bis(3,4-dicarboxyphenyl) sulfoxide dianhydride, thiodiphthalic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 9,9-bis(3,4-dicarboxyphenyl) sulfone dianhydride Aromatic tetracarboxylic dianhydrides such as 9,9-bis[4-(3,4'-dicarboxyphenyl)fluorene dianhydride and 9,9-bis[4-(3,4'-dicarboxyphenoxy)phenyl]fluorene dianhydride, cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, 3,4-dicarboxy-1-cyclohexyl succinic dianhydride, and 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride. In addition, two or more of these tetracarboxylic dianhydrides may be used in combination. Among these tetracarboxylic dianhydrides, pyromellitic dianhydride (PMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 2,2-bis[3,4-(dicarboxyphenoxy)phenyl]propane dianhydride (BPADA), and oxydiphthalic anhydride (ODPA) are particularly preferred.

[0034] Specific examples of the diamine compound include p-phenylenediamine (PPD), m-phenylenediamine (MPDA), 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane (MDA), 2,2-bis-(4-aminophenyl)propane, 3,3'-diaminodiphenyl sulfone (33DDS), 4,4'-diaminodiphenyl sulfone (44DDS), 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether (34ODA), 4,4'-diaminodiphenyl Aromatic diamines such as phenyl ether (ODA), 1,5-diaminonaphthalene, 4,4'-diaminodiphenyldiethylsilane, 4,4'-diaminodiphenylsilane, 4,4'-diaminodiphenylethylphosphine oxide, 1,3-bis(3-aminophenoxy)benzene (133APB), 1,3-bis(4-aminophenoxy)benzene (134APB), 1,4-bis(4-aminophenoxy)benzene, bis[4-(3-aminophenoxy)phenyl]sulfone (BAPSM), bis[4-(4-aminophenoxy)phenyl]sulfone (BAPS), 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 2,2-bis(3-aminophenyl)1,1,1,3,3,3-hexafluoropropane, 2,2-bis(4-aminophenyl)1,1,1,3,3,3-hexafluoropropane, 9,9-bis(4-aminophenyl)fluorene, etc. Furthermore, two or more of these diamine compounds may be used in mixture.

[0035] As the polyimide resin, from the viewpoint of durability, thermal conductivity and bending durability, preferably, a polyimide resin (BPDA-PPD) composed of 3,3',4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine, or a polyimide resin (BPDA-ODA) composed of 3,3',4,4'-biphenyltetracarboxylic dianhydride and 4,4'-diaminodiphenyl ether, or a polyimide resin (PMDA-ODA) composed of pyromellitic dianhydride and 4,4'-diaminodiphenyl ether can be cited. In addition, a combination of these polyimide resins can also be used.

[0036] <Construction of the fixing belt>

[0037] The fixing belt according to the embodiment of the present invention is mainly composed of a base layer, an undercoat layer and a release layer. These constituent layers will be described in detail below.

[0038] (1-1) Base material layer

[0039] The base layer is a seamless tubular layer, mainly formed of a polyimide resin, a thermally conductive filler and an abrasion-resistant filler. In the fixing belt of the embodiment of the present invention, from the viewpoint of mechanical properties, the thickness of the base layer is preferably in the range of 30 μm to 100 μm, and is further preferably in the range of 50 μm to 80 μm in consideration of the ease of manufacturing and the flexibility required for the fixing belt.

[0040] In addition, in order to make the thermal conductivity of the substrate layer greater than 0.7 W / mK while suppressing the degradation of mechanical properties and scraping of the substrate layer, the amount of thermally conductive filler added is preferably in the range of greater than 5 parts by volume and less than 50 parts by volume, more preferably in the range of greater than 7 parts by volume and less than 50 parts by volume, and further preferably in the range of greater than 14 parts by volume and less than 30 parts by volume.

[0041] Similarly, in order to suppress scraping of the substrate layer while maintaining the thermal conductivity and mechanical properties of the substrate layer, the amount of wear-resistant filler added is preferably in the range of more than 0.1 volume parts and less than 10 volume parts, more preferably in the range of more than 0.5 volume parts and less than 8 volume parts, further preferably in the range of more than 0.5 volume parts and less than 5 volume parts, and particularly preferably in the range of more than 1 volume part and less than 5 volume parts.

[0042] (1-2) Primer

[0043] The primer layer is a layer that plays the role of bonding the substrate layer and the release layer, and is composed of the following resins: adhesive resins such as fluororesins and acrylic resins; water-soluble heat-resistant resins such as water-soluble polyamide-imide resins and water-soluble polyimide resins, etc. In addition, in the fixing belt of the embodiment of the present invention, the thickness of the primer layer can be adjusted within the range of 1 μm or more and 10 μm or less as long as it is a thickness that allows bonding.

[0044] (1-3) Release layer

[0045] The release layer is preferably formed of at least one substance selected from the group consisting of fluororesin, silicone rubber and fluororubber. From the viewpoint of the release property of toner, etc., it is preferably formed of fluororesin. As fluororesin, for example, polytetrafluoroethylene (PTFE), polytetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP) can be cited. These substances can be used as monomers or in combination. In addition, the release layer is preferably a thickness in the range of 6 μm or more and 35 μm or less.

[0046] <An Example of a Method for Manufacturing a Fixing Belt>

[0047] The fixing belt of this embodiment is mainly manufactured through a polyimide precursor solution preparation process, a substrate layer forming process, a primer layer forming process, a release layer forming process, a calcination process, and a demolding process. However, this manufacturing method is only an example and does not limit the invention of this application. The above-mentioned manufacturing processes will be described in detail below.

[0048] (1) Polyimide Precursor Solution Preparation Process

[0049] In the polyimide precursor solution preparation step, the thermally conductive filler and the wear-resistant filler are added to the polyimide precursor solution prepared as follows to obtain a filler-containing polyimide precursor solution. In addition, the method of adding the thermally conductive filler and the wear-resistant filler to the polyimide precursor solution is not particularly limited, and it can be a method of directly adding the thermally conductive filler and the wear-resistant filler to the polyimide precursor solution, or a method of adding the thermally conductive filler and the wear-resistant filler when preparing the polyimide precursor solution.

[0050] In addition, as the organic polar solvent that can prepare the above-mentioned polyimide precursor solution, for example, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, hexamethylphosphoric acid triamide, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, etc. can be cited. Among these diamines, N,N-dimethylacetamide (DMAC) and N-methyl-2-pyrrolidone (NMP) are particularly preferred. In addition, these organic polar solvents can be used alone or in combination. In addition, aromatic hydrocarbons such as toluene and xylene can be mixed in the organic polar solvent.

[0051] In this embodiment, it is preferred that 4,4'-diaminodiphenyl ether is used as a diamine and pyromellitic acid dianhydride is used as a tetracarboxylic acid dianhydride, and it is particularly preferred that p-phenylenediamine is used as a diamine and 3,3',4,4'-biphenyltetracarboxylic acid dianhydride is used as a tetracarboxylic acid dianhydride. The polyimide resin obtained from these monomers has excellent toughness in terms of mechanical properties, and does not soften or melt like a thermoplastic resin even when the temperature of the fixing belt rises, showing excellent heat resistance and mechanical properties.

[0052] Furthermore, to the polyimide precursor solution, a resin such as polyamideimide or polyethersulfone may be added if necessary within a range not impairing the gist of the present invention.

[0053] In addition, as the polyimide precursor solution, known additives such as dispersants, solid lubricants, sedimentation inhibitors, leveling agents, surface conditioners, water absorbents, anti-gelling agents, antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, anti-skinning agents, surfactants, antistatic agents, defoamers, antibacterial agents, antifungal agents, preservatives, thickeners, etc. can be added within the range that does not impair the properties of the present invention. A dehydrating agent and an imidization catalyst in a stoichiometric amount or more can be further added to the polyimide precursor solution.

[0054] In addition, the polyimide precursor solution is preferably subjected to treatments such as filtration and defoaming before use.

[0055] (2) Base material layer forming process

[0056] In the substrate layer forming step, after the polyimide precursor solution is uniformly coated on the outer peripheral surface of the cylindrical core body using an annular die, the core body with the coating film is heated. In addition, the heating temperature at this time is preferably a temperature at which the organic polar solvent volatilizes but does not undergo imidization, for example, preferably a temperature below 200°C, and the temperature can be gradually increased to 300°C to 450°C.

[0057] (3) Primer layer forming step

[0058] In the primer formation step, the core body formed with the substrate layer is immersed in the primer liquid, so that the primer liquid is uniformly applied on the outer peripheral surface of the substrate layer, wherein the primer liquid contains a dispersion medium of a fluorine-containing resin and the above-mentioned water-soluble heat-resistant resin. Then, the substrate layer with the coating film (with the core body) is heated. In addition, the heating temperature at this time is preferably a temperature at which the solvent evaporates but the previous polyimide precursor does not undergo imidization, for example, preferably a temperature within a range of 200°C or less.

[0059] (4) Release layer forming process

[0060] In the release layer forming step, after the fluororesin dispersion is applied, the coating film is dried, and the coating film of the fluororesin dispersion is formed on the primer layer.

[0061] (5) Calcination process

[0062] In the calcination process, the material obtained in the release layer forming process is calcined to obtain a fixing belt. The calcination temperature at this time is preferably a temperature in the range of 300°C to 450°C. In addition, the treatment time is preferably in the range of 30 minutes to 2 hours. The completion of the imidization of the substrate layer and the calcination of the fluororesin of the release layer are carried out simultaneously, which can not only shorten the manufacturing time of the fixing belt and improve the thermal efficiency, but also improve the adhesion of each layer.

[0063] (6) Demolding process

[0064] In the demolding process, the fixing belt is pulled out from the core.

[0065] <Design concept of fuser belt>

[0066] In an image forming device using a conventional fixing belt, the fixing belt melts and fixes the toner on a recording medium such as paper. At this time, the guide portion of the heater provided on the inner side of the fixing belt contacts the fixing belt substrate layer, and the substrate layer is scraped due to friction. At this time, the friction applied to the substrate layer of the fixing belt is composed of the combined force of the force in the thickness direction of the fixing belt and the force in the sliding direction. Since the surface hardness of the substrate layer is increased by adding a wear-resistant filler with an old Mohs hardness of 5 or more to the substrate layer, the fixing belt of this embodiment becomes effective against friction relative to the thickness direction of the substrate layer. However, the inclusion of a filler with a high old Mohs hardness causes the inner surface of the substrate layer to form unevenness, and if the inner surface roughness Rz in the sliding direction is too large, the wear-resistant filler itself will fall off due to the force in the sliding direction, so the substrate layer becomes easy to be scraped. Therefore, as a fixing belt, while adding a wear-resistant filler with an old Mohs hardness of 5 or more, it is necessary to control the inner surface roughness Rz in the sliding direction to be less than 2.0.

[0067] The fixing belt of the present embodiment may include an elastic layer between the base layer and the release layer.

[0068] Examples and Comparative Examples

[0069] The fixing belt of the present embodiment will be described in more detail below by showing examples and comparative examples. However, the present invention is not limited to these examples and comparative examples.

[0070] Example 1

[0071] 1. Production of fixing belt

[0072] First, a mold having an outer diameter of 18 mm and a length of 500 mm, the surface of which was subjected to a release treatment, was prepared.

[0073] Then, graphite (diameter 2 μm, shape: plate-like) as a thermally conductive filler is added to a polyamic acid solution (composition: 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) / p-phenylenediamine (PPD): isophthalic dianhydride (PMDA) / 4,4'-diaminodiphenyl ether (ODA) = 8:2 ratio, solid content 18.4 parts by mass) so that the solid content relative to the polyamic acid solution is 26.5 parts by volume, and the polyamic acid solution is stirred until the graphite becomes uniform. Titanium oxide (diameter 0.2 μm, shape: spherical) with an old Mohs hardness of 7 is further added as a wear-resistant filler so that the solid content relative to the polyamic acid solution is 3.0 parts by volume, and the polyamic acid solution is stirred until the titanium oxide becomes uniform, thereby obtaining a filler-containing polyimide precursor solution with a viscosity of 1000 poise.

[0074] Then, the mold was immersed in the polyimide precursor solution containing fillers up to the portion of 400 mm, and after the polyimide precursor solution containing fillers was applied to the outer surface of the mold, a ring-shaped concave mold with an inner diameter of 19.4 mm was dropped from the upper end of the mold by its own weight, and the polyimide precursor solution containing fillers was cast on the surface of the mold. After that, as a drying process, the mold was placed in an oven at 120° C., dried for 30 minutes, and then heated to 200° C. in 20 minutes, maintained at the same temperature for 20 minutes, and cooled to room temperature, thereby producing a base layer.

[0075] Then, the primer liquid was applied to the surface of the base material layer and dried at 150° C. for 10 minutes to prepare a primer layer.

[0076] After that, the PFA dispersion was coated on the undercoat layer to a thickness of 12 μm after calcination, and then dried at room temperature for 30 minutes, gradually heated to 350° C., and calcined at 350° C. for 30 minutes to obtain a fixing belt with a substrate layer thickness of 60 μm as the target product.

[0077] 2. Physical property evaluation

[0078] (1) Surface roughness of the inner surface of the substrate layer

[0079] According to JIS B0601-1994, under the conditions of a feed speed of 0.1 mm / sec, a cutoff value of 0.8 mm, and a measurement length of 2.5 mm, the surface roughness Rz was measured at any 6 points in the sliding direction. The surface roughness Rz was 0.51 μm on average. The surface roughness Rz is the surface roughness Rz of the inner surface of the base material layer of the fixing belt produced as described above.

[0080] (2) Check the scraping condition of the substrate layer

[0081] The fixing belt of this embodiment was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times. It was confirmed that there was no scraping compared with the fixing belt without wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the above-mentioned fixing belt manufacturing method).

[0082] (3) Measurement of thermal conductivity of substrate layer

[0083] Referring to JIS R2616, only the base layer of the fixing belt was cut into a 2 cm × 2 cm piece, and a transistor was placed on one surface of the base layer with thermal grease, and a heat sink (made of aluminum) was placed on the opposite surface with thermal grease. Then, the temperature was raised by power until the temperature of the transistor reached 60°C, and then the base layer was heated at 60°C for 3 minutes, and the temperature A of the transistor surface and the temperature B of the base layer surface with the heat sink were measured using a thermocouple. In addition, the power consumption at this time was measured, and the thermal resistance was calculated using the following formula using the temperature of each surface and the power consumption.

[0084] Thermal resistance = (transistor surface temperature A - substrate surface temperature B) / power consumption

[0085] Furthermore, the thermal conductivity was calculated from the following formula using the thermal resistance calculated above.

[0086] Thermal conductivity = film thickness of substrate layer / (cross-sectional area of ​​transistor × thermal resistance)

[0087] In addition, the thermal conductivity of the base material layer of the fixing belt of this example is 1.18 W / mK.

[0088] (4) Determination of elongation

[0089] The preparation of the primer layer and the application of the PFA dispersion in the above “1. Preparation of fixing belt” were omitted, and the base layer was simply heated to 350° C. and calcined at 350° C. for 30 minutes to obtain a base layer as a single body.

[0090] After cutting the obtained base layer, the base layer was punched out in the long side direction in the form of a JIS-3 dumbbell (JIS K6301) to prepare a sample. The sample was tested using Autograph AGS-50A manufactured by Shimadzu Corporation with a chuck distance of 30 mm and a tensile speed of 50 mm / min, and the tensile elongation at break was taken as the elongation. In addition, the elongation of the base layer in this example was 6.6%.

[0091] (5) Determination of puncture strength

[0092] The preparation of the primer layer and the application of the PFA dispersion in the above “1. Preparation of fixing belt” were omitted, and the base layer was simply heated to 350° C. and calcined at 350° C. for 30 minutes to obtain a base layer as a single body.

[0093] The obtained substrate layer was set in a fixing fixture. Using Autograph AGS-50A manufactured by Shimadzu Corporation, the substrate layer was pierced with a puncture needle (Imada / TKS-250N) at a test speed of 5 mm / min in accordance with JIS Z1707 1997, and the test force at the time of rupture was measured as the puncture strength. In addition, the puncture strength of the substrate layer in this embodiment was 1.2 kgf.

[0094] Example 2

[0095] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 20.5 parts by volume, and the wear-resistant filler was changed to alumina (diameter 10 μm, shape: plate-like) with an old Mohs hardness of 9 and alumina was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 3.0 parts by volume.

[0096] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.04 W / mK, the roughness Rz was 1.11 μm, the puncture strength was 1.4 kgf, and the elongation was 9.7%.

[0097] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0098] Example 3

[0099] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 14.5 parts by volume, and the wear-resistant filler was changed to alumina (diameter 5 μm, shape: plate-like) with an old Mohs hardness of 9 and alumina was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 7.5 parts by volume.

[0100] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 0.89 W / mK, the roughness Rz was 1.1102 μm, the puncture strength was 1.7 kgf, and the elongation was 5.9%.

[0101] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0102] Example 4

[0103] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 21.5 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 1 μm, shape: spherical) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 3.0 parts by volume.

[0104] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.14 W / mK, the roughness Rz was 0.70 μm, the puncture strength was 1.5 kgf, and the elongation was 6.8%.

[0105] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0106] Example 5

[0107] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 15.0 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 5 μm, shape: needle-like) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 8.0 parts by volume.

[0108] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 0.94 W / mK, the roughness Rz was 1.39 μm, the puncture strength was 1.1 kgf, and the elongation was 8.2%.

[0109] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0110] Example 6

[0111] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 20.5 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 1 μm, shape: spherical) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 3.0 parts by volume.

[0112] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.21 W / mK, the roughness Rz was 1.25 μm, the puncture strength was 1.1 kgf, and the elongation was 9.9%.

[0113] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0114] Example 7

[0115] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 20.5 parts by volume, and the wear-resistant filler was changed to alumina (diameter 2 μm, shape: plate-like) with an old Mohs hardness of 9 and alumina was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 3.0 parts by volume.

[0116] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.18 W / mK, the roughness Rz was 1.26 μm, the puncture strength was 1.2 kgf, and the elongation was 8.8%.

[0117] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0118] Example 8

[0119] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 20.5 parts by volume, and the wear-resistant filler was changed to alumina (diameter 7 μm, shape: plate-like) with an old Mohs hardness of 9 and alumina was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 3.0 parts by volume.

[0120] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.22 W / mK, the roughness Rz was 1.43 μm, the puncture strength was 1.0 kgf, and the elongation was 8.7%.

[0121] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0122] Example 9

[0123] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 14.5 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 0.2 μm, shape: plate-like) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 7.5 parts by volume.

[0124] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 0.80 W / mK, the roughness Rz was 0.61 μm, the puncture strength was 1.3 kgf, and the elongation was 4.6%.

[0125] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0126] Example 10

[0127] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 25.0 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 0.2 μm, shape: plate-like) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 5.0 parts by volume.

[0128] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.32 W / mK, the roughness Rz was 0.55 μm, the puncture strength was 0.9 kgf, and the elongation was 3.1%.

[0129] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0130] Embodiment 11

[0131] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 14.5 parts by volume, and the wear-resistant filler was changed to silica (diameter 0.3 μm, shape: spherical) with an old Mohs hardness of 8 and silica was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 7.5 parts by volume.

[0132] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 0.78 W / mK, the roughness Rz was 0.54 μm, the puncture strength was 1.8 kgf, and the elongation was 19.6%.

[0133] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0134] Example 12

[0135] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 14.5 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 5.0 μm, shape: needle-like) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 7.5 parts by volume.

[0136] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 0.89 W / mK, the roughness Rz was 0.84 μm, the puncture strength was 1.5 kgf, and the elongation was 11.0%.

[0137] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0138] Example 13

[0139] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 14.5 parts by volume, and the wear-resistant filler was changed to silica (diameter 0.5 μm, shape: spherical) with an old Mohs hardness of 8 and silica was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 7.5 parts by volume.

[0140] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 0.79 W / mK, the roughness Rz was 0.51 μm, the puncture strength was 2.0 kgf, and the elongation was 15.8%.

[0141] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0142] Embodiment 14

[0143] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 25.0 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 0.2 μm, shape: plate-like) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 3.0 parts by volume.

[0144] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.27 W / mK, the roughness Rz was 0.56 μm, the puncture strength was 1.1 kgf, and the elongation was 5.6%.

[0145] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0146] Embodiment 15

[0147] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 14.5 parts by volume, and the wear-resistant filler was changed to alumina (diameter 0.3 μm, shape: spherical) with an old Mohs hardness of 9 and alumina was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 7.5 parts by volume.

[0148] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 0.87 W / mK, the roughness Rz was 0.61 μm, the puncture strength was 1.7 kgf, and the elongation was 17.6%.

[0149] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0150] Example 16

[0151] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 22.5 parts by volume, and the wear-resistant filler was changed to alumina (diameter 0.2 μm, shape: plate-like) with an old Mohs hardness of 9 and alumina was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 5.0 parts by volume.

[0152] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.15 W / mK, the roughness Rz was 0.56 μm, the puncture strength was 1.2 kgf, and the elongation was 7.1%.

[0153] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0154] Embodiment 17

[0155] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 25.0 parts by volume, and the wear-resistant filler was changed to silica (diameter 0.2 μm, shape: spherical) with an old Mohs hardness of 8 and silica was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 5.0 parts by volume.

[0156] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.26 W / mK, the roughness Rz was 0.68 μm, the puncture strength was 0.9 kgf, and the elongation was 5.3%.

[0157] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0158] Embodiment 18

[0159] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 22.0 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 0.2 μm, shape: plate-like) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 5.0 parts by volume.

[0160] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.29 W / mK, the roughness Rz was 0.65 μm, the puncture strength was 1.1 kgf, and the elongation was 6.9%.

[0161] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0162] Embodiment 19

[0163] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 18.0 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 0.2 μm, shape: plate-like) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 8.0 parts by volume.

[0164] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.21 W / mK, the roughness Rz was 1.05 μm, the puncture strength was 0.8 kgf, and the elongation was 7.0%.

[0165] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0166] Embodiment 20

[0167] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 3 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 20.0 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 0.2 μm, shape: plate-like) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 5.0 parts by volume.

[0168] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.05 W / mK, the roughness Rz was 0.58 μm, the puncture strength was 1.6 kgf, and the elongation was 13.5%.

[0169] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0170] Embodiment 21

[0171] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 17.0 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 0.2 μm, shape: plate-like) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 7.5 parts by volume.

[0172] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.03 W / mK, the roughness Rz was 1.01 μm, the puncture strength was 1.0 kgf, and the elongation was 9.5%.

[0173] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0174] Embodiment 22

[0175] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 5 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 19.0 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 0.2 μm, shape: plate-like) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 5.0 parts by volume.

[0176] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.15 W / mK, the roughness Rz was 0.92 μm, the puncture strength was 0.9 kgf, and the elongation was 8.1%.

[0177] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0178] Embodiment 23

[0179] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 18.0 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 0.2 μm, shape: plate-like) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 5.0 parts by volume.

[0180] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.03 W / mK, the roughness Rz was 0.99 μm, the puncture strength was 1.2 kgf, and the elongation was 12.1%.

[0181] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0182] Embodiment 24

[0183] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 19.5 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 0.2 μm, shape: plate-like) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 3.0 parts by volume.

[0184] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.07 W / mK, the roughness Rz was 1.11 μm, the puncture strength was 1.2 kgf, and the elongation was 12.6%.

[0185] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0186] Embodiment 25

[0187] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 20.5 parts by volume, and the wear-resistant filler was changed to alumina (diameter 10 μm, shape: plate-like) with an old Mohs hardness of 9 and alumina was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 0.2 parts by volume.

[0188] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.08 W / mK, the roughness Rz was 1.22 μm, the puncture strength was 1.3 kgf, and the elongation was 13.7%.

[0189] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0190] Embodiment 26

[0191] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 20.5 parts by volume, and the wear-resistant filler was changed to alumina (diameter 10 μm, shape: plate-like) with an old Mohs hardness of 9 and alumina was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 0.5 parts by volume.

[0192] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.08 W / mK, the roughness Rz was 1.25 μm, the puncture strength was 1.2 kgf, and the elongation was 14.6%.

[0193] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0194] Embodiment 27

[0195] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 20.5 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 1 μm, shape: spherical) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 1.0 parts by volume.

[0196] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.06 W / mK, the roughness Rz was 1.23 μm, the puncture strength was 1.3 kgf, and the elongation was 16.3%.

[0197] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0198] Embodiment 28

[0199] A fixing belt was obtained by the same method as used in Example 1, except that PMDA / ODA of the polyamic acid solution was changed to BPDA / ODA, and the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 20.5 parts by volume, and the wear-resistant filler was changed to titanium oxide (diameter 1 μm, shape: spherical) with an old Mohs hardness of 7 and titanium oxide was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 3.0 parts by volume.

[0200] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.22 W / mK, the roughness Rz was 1.25 μm, the puncture strength was 1.1 kgf, and the elongation was 8.2%.

[0201] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0202] Embodiment 29

[0203] A fixing belt was obtained by the same method as used in Example 1, except that PMDA / ODA of the polyamic acid solution was changed to BPDA / ODA, and the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content thereof was 20.5 parts by volume relative to the solid content of the polyamic acid solution, and alumina was added to the polyamic acid solution so that the solid content thereof was 3.0 parts by volume relative to the solid content of the polyamic acid solution while the wear-resistant filler was changed to alumina (diameter 10 μm, shape: plate-like) with an old Mohs hardness of 9.

[0204] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.19 W / mK, the roughness Rz was 1.41 μm, the puncture strength was 1.0 kgf, and the elongation was 6.1%.

[0205] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0206] Embodiment 30

[0207] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content thereof was 20.5 parts by volume relative to the solid content of the polyamic acid solution, and the wear-resistant filler was changed to alumina (diameter 10 μm, shape: plate-like) with an old Mohs hardness of 9 and alumina was added to the polyamic acid solution so that the solid content thereof was 3.0 parts by volume relative to the solid content of the polyamic acid solution.

[0208] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.21 W / mK, the roughness Rz was 1.38 μm, the puncture strength was 1.2 kgf, and the elongation was 11.3%.

[0209] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0210] Embodiment 31

[0211] A fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to graphite (diameter 10 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 20.5 parts by volume, and the wear-resistant filler was changed to alumina (diameter 10 μm, shape: plate-like) with an old Mohs hardness of 9 and alumina was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 3.0 parts by volume.

[0212] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.23 W / mK, the roughness Rz was 1.50 μm, the puncture strength was 1.1 kgf, and the elongation was 9.4%.

[0213] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0214] Embodiment 32

[0215] The fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to carbon nanotubes (diameter 5 μm (×150 nm), shape: needle-like) and the carbon nanotubes were added to the polyamic acid solution so that the solid content of the polyamic acid solution was 25.0 parts by volume, and the wear-resistant filler was changed to alumina (diameter 10 μm, shape: plate-like) with an old Mohs hardness of 9 and alumina was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 3.0 parts by volume.

[0216] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 1.97 W / mK, the roughness Rz was 1.26 μm, the puncture strength was 1.3 kgf, and the elongation was 6.3%.

[0217] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0218] Embodiment 33

[0219] The fixing belt was obtained by the same method as used in Example 1, except that the thermal conductive filler was changed to carbon nanotubes (diameter 5 μm (×150 nm), shape: needle-like) and the carbon nanotubes were added to the polyamic acid solution so that the solid content of the polyamic acid solution was 25.0 parts by volume, and the wear-resistant filler was changed to alumina (diameter 10 μm, shape: plate-like) with an old Mohs hardness of 9 and alumina was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 5.0 parts by volume.

[0220] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 2.09 W / mK, the roughness Rz was 1.67 μm, the puncture strength was 1.2 kgf, and the elongation was 3.7%.

[0221] In addition, as was done in Example 1, the fixing belt of this example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that there was no scraping compared to the fixing belt not containing wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0222] Comparative Example 1

[0223] 1. Production of fixing belt

[0224] First, a mold having an outer diameter of 18 mm and a length of 500 mm, the surface of which was subjected to a release treatment, was prepared.

[0225] Then, carbon nanotubes (diameter 5 μm (×150 nm), shape: needle-shaped) as thermally conductive fillers are added to a polyamic acid solution (composition: 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) / p-phenylenediamine (PPD): isophthalic dianhydride (PMDA) / 4,4'-diaminodiphenyl ether (ODA) = 8:2 ratio, solid content 18.4 parts by mass) so that the solid content relative to the polyamic acid solution is 25.0 parts by volume, and the polyamic acid solution is stirred until the carbon nanotubes become uniform. Titanium oxide (diameter 5.0 μm, shape: needle-shaped) with an old Mohs hardness of 7 as a wear-resistant filler is further added so that the solid content relative to the polyamic acid solution is 5.0 parts by volume, and the polyamic acid solution is stirred until the titanium oxide becomes uniform, thereby obtaining a filler-containing polyimide precursor solution with a viscosity of 3000 poise.

[0226] Then, the mold was immersed in the polyimide precursor solution containing fillers up to the 400mm portion, and after the polyimide precursor solution containing fillers was coated on the outer surface of the mold, a ring-shaped concave mold with an inner diameter of 18.3mm was dropped from the upper end of the mold by its own weight, and the polyimide precursor solution containing fillers was cast on the surface of the mold, so that the thickness of the final substrate layer was about 5μm. After that, as a drying process, the mold was placed in an oven at 75°C, and after drying for 60 minutes, a ring-shaped concave mold with an inner diameter of 19.30mm was further used to cast the polyimide precursor solution containing fillers on the coating film, so that the final film thickness of the substrate layer was about 60μm. After that, as a drying process, the mold was placed in an oven at 120°C, dried for 30 minutes, and then heated to 200°C in 20 minutes, kept at the same temperature for 20 minutes, and cooled to room temperature, thereby producing a substrate layer.

[0227] Then, the primer liquid was applied to the surface of the base material layer and dried at 150° C. for 10 minutes to prepare a primer layer.

[0228] After that, the PFA dispersion was coated on the undercoat layer to a thickness of 12 μm after calcination, and then dried at room temperature for 30 minutes, and then gradually heated to 350° C. and calcined at 350° C. for 30 minutes to obtain a fixing belt with a thickness of 60 μm as a target product.

[0229] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 2.03 W / mK, the roughness Rz was 2.10 μm, the puncture strength was 0.8 kgf, and the elongation was 3.2%.

[0230] In addition, as was done in Example 1, the fixing belt of this comparative example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that it was scraped to the same extent as the fixing belt without wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0231] Comparative Example 2

[0232] The fixing belt was obtained by the same method as used in Example 1, except that PMDA / ODA of the polyamic acid solution was changed to BPDA / ODA, the thermal conductive filler was changed to graphite (diameter 8 μm, shape: plate-like) and graphite was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 15.0 parts by volume, and the wear-resistant filler was changed to silica (diameter 7 μm, shape: spherical) with an old Mohs hardness of 8 and silica was added to the polyamic acid solution so that the solid content of the polyamic acid solution was 8.0 parts by volume.

[0233] The physical properties of the obtained fixing belt and base layer were measured by the same method as used in Example 1, and the thermal conductivity was 0.92 W / mK, the roughness Rz was 2.23 μm, the puncture strength was 1.0 kgf, and the elongation was 11.6%.

[0234] In addition, as was done in Example 1, the fixing belt of this comparative example was assembled to the fixing device of the printer, and the scraping of the base layer was confirmed when the fixing belt was rotated 60,000 times, thereby confirming that it was scraped to the same extent as the fixing belt without wear-resistant filler (the fixing belt manufactured without adding wear-resistant filler in the manufacturing method of the fixing belt shown in Example 1).

[0235] Industrial Applicability

[0236] The fixing belt of the present invention has the following characteristics: while having the same release properties as before, the scraping of the base layer is suppressed compared with before, so that the torque increase caused by long-term use can be suppressed, and the high thermal conductivity can be further maintained. The fixing belt of the present invention can be used as an image fixing device and a fixing belt, a fixing tube, etc. of the image fixing device, and the image fixing device is an image fixing device of an image forming device such as a copier and a laser printer.

Claims

1. A fixing belt, wherein: The fixing belt comprises a base material layer including a polyimide resin, a thermally conductive filler and an abrasion-resistant filler. The wear-resistant filler has an old Mohs hardness of 5 or more, The diameter (particle size) of the wear-resistant filler is within the range of 0.1 μm or more and 10 μm or less. The amount of the wear-resistant filler added to the base layer is within a range of 0.1 parts by volume or more and 10 parts by volume or less. The thermal conductivity of the substrate layer is greater than 0.7 W / mK. The inner surface roughness Rz of the substrate layer in the sliding direction is 2.0 μm or less.

2. The fixing belt according to claim 1, wherein: The wear-resistant filler may be in any shape of plate, needle, or sphere.

3. The fixing belt according to claim 1 or 2, wherein: The diameter (particle size) of the thermally conductive filler is within the range of 0.1 μm to 10 μm. The amount of the thermally conductive filler added to the base material layer is within a range of 5 parts by volume or more and 50 parts by volume or less.

4. The fixing belt according to any one of claims 1 to 3, wherein: The wear-resistant filler has an old Mohs hardness in the range of 5 or more and 9 or less.

5. The fixing belt according to any one of claims 1 to 4, wherein: The thermal conductivity of the base material layer is within a range of 0.7 W / mK to 2.5 W / mK.

6. The fixing belt according to any one of claims 1 to 5, wherein: The inner surface roughness Rz of the substrate layer in the sliding direction is within a range of 0.3 μm to 2.0 μm.

7. The fixing belt according to any one of claims 1 to 6, wherein: The elongation of the base material layer is within a range of 2% to 20%.

8. The fixing belt according to any one of claims 1 to 7, wherein: The puncture strength of the base material layer is within a range of 0.9 kgf to 2.0 kgf.